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GEOL6351-Basin Modeling - Day6 10-08-2022-AM
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00:00 start with today is um I'm gonna over a series of petrol motor
00:11 both one dimensional and two dimensional from kind of basins and one of the
00:17 of them you've already seen and other are new. And we're going to
00:22 through the figures just to see um know, talk about how to understand
00:29 from Petra mode, where sensitivities are . So the first basin that I'm
00:34 to talk about is this fore arc in California. And this was the
00:40 , well, uh that you did on friday afternoon during the second weekend
00:47 class. So this was the Sanya basin and this basin is a fore
00:53 basin in California. And we haven't talked about four basins yet, but
00:57 do it today and I'll start So, for a basin is a
01:02 basin that forms between the volcanic arc you have, you know, at
01:09 zones and basically the script of sediments the trench. So, what you
01:15 in this picture here is here a ducting slab abducting oceanic little sphere and
01:25 in a subduction zone like this um that are naturally present in the cursed
01:32 the oceanic crust. They actually get of that slab at some point in
01:37 and they move upwards and then they melting of the rocks and volcanism and
01:44 you form what we call a volcanic and that arc, of course it's
01:50 mountain range, right, a series volcanoes is a mountain range. And
01:55 that arc erodes and the rocks, sediments that are formed in that way
02:02 are transported downhill into the direction of fore arc basin. Now, when
02:09 subduction oceanic little sphere goes down deeper the Casino sphere into the mantle,
02:16 sub ducting oceanic little spheres or mental sphere cursed has always a layer of
02:23 on top and those are marine they fall down on the ocean floor
02:27 they're everywhere. And so when you such an oceanic slab, some of
02:34 marine sediments, they don't go down the slab, but they're scraped off
02:39 they end up in a paul that see here, it's called an accretion
02:44 wedge. So it's accretion of those that come from the ocean floor.
02:50 so they pile up in front of continent and they may form, you
02:55 , a low mountain range. And can see that here, that mountain
02:59 may erode as well. And those may end up in that for our
03:03 as well. So that for our informs on the four sides of the
03:08 , that's why it's called a fore basin. And again it gets the
03:15 from the ark and some of them be from the accretion ery reg because
03:24 we are very close to the coastline we're very close to a subduction zone
03:31 , what you see is that such fore arc basin is flooded. So
03:36 sea somehow finds a way in and have basically, you formed an in
03:42 inland sea or a lake on top that fore arc basin. When that
03:49 , you may find may you may very good source rocks right? Because
03:53 you have a water layer with a of organic material and so you have
03:58 potential to form a really good source . These rocks that are coming off
04:05 sediments that are coming up that four and maybe that's a creature Neri
04:10 Those settlements are probably rather coarse grains when they're being deposited they may form
04:18 reservoir rocks. Now furthermore, when subduction is going on and these
04:25 these ocean sediments, marine sediments power here on this precautionary wretch um that
04:34 pushes into the basin and you can of see that here. Oops,
04:38 to remove it, You can see here, you see that. So
04:41 sediments here, those sedimentary layers, are really strongly deformed, the buckle
04:47 falls, etcetera. And that is for these four are basins. They
04:52 um basins, sedimentary basins that are very much deformed and therefore they have
04:59 very complex structure. Not not like rifts on every kind of understand what
05:05 structure should look like. These. basins are really um Yeah, so
05:11 deformed that it becomes very complex, you can also imagine that if you
05:15 to fold these these sedimentary layers that make very good straps. So these
05:22 basins, they, you know, may have these source rocks right when
05:27 area was flooded by an ocean. They have good reservoir rocks, we
05:33 , you know, the source of reservoir works is close by and then
05:37 of all the deformation and folding that going on, they may also have
05:42 traps. So for our basins are where the petroleum industry is either present
05:49 looking. And that is also with basin here in California. So it's
05:54 Great Valley in California. So that the first basin that we looked at
06:00 the second weekend. Now, what with this subduction zone as you know
06:06 in California, we don't have a zone, but we have the san
06:10 fault zone. And at one point time this um this subduction came to
06:19 end. The slap broke off and deeper into the mantle and we started
06:23 form a Son Andreas fault zone which strikes the fold or transform fault where
06:29 plates are moving parallel with respect to another. So, that's what happened
06:34 . All right, so where are again? We are here in the
06:38 Valley valley of California here, for is san Francisco. Um Here's san
06:47 , here is the Los Angeles Los and the Los Angeles basin. So
06:52 gives you an idea where we are California coastal ranges, they are the
06:58 Neri wedge that I was just talking . So these, these California coastal
07:03 , that's a low mountain range. ? And if you look at those
07:07 , they are script of ocean ocean basin sediments, the Great
07:15 this is our fore arc basin and the share of Nevada here in the
07:23 and the cascades here in the They are the volcanic arc.
07:31 we see the build up the ark inland, the four art basin in
07:37 center and then the creature very Those are the California Coast coast
07:46 So, by looking at this you also get immediately an idea of
07:50 large that for our basin is. , It extends all the way from
07:56 past san Francisco. And I'm here southern California or central southern California.
08:03 here you see the width. So these four are basins can be fairly
08:09 basins. This particular for our base the great Valley was at some point
08:15 time flooded. You can still see in turn to remove some of
08:18 So here is san Francisco and I know if you've ever been in san
08:23 and maybe saw pictures of san but you see a little bit of
08:27 inland water here. Do you see this area here, this great valley
08:33 from that opening basically here in the past. So this great Valley was
08:39 some point in time, under a of water. Questions about this.
08:49 later this morning, I'm gonna come to these four art basis again.
08:54 go ahead, I'm sorry, but , but the Great Valley is an
08:59 , I mean, most four arcs not nearly as big as the Great
09:02 . I mean the one around, guess Sumatra is pretty big and I
09:10 Ecuador and Peru, the Dallara area pretty big, but otherwise four arcs
09:17 to be and then of course the tobago trough. But I mean,
09:23 you think most other four arcs are that big or maybe I'm, I
09:27 Alaska is pretty big too, isn't ? Okay, alright. I'll shut
09:30 . So the point is, is it's the same as, as rift
09:34 , right? You can have a zone that's 50 or 30 kilometers wide
09:39 a few 100 kilometers long and you have rift zones that are 100 to
09:44 kilometers wide and 1500 kilometers long or than 2000 kilometers long. Like what
09:51 have in the East african rift. , So there's say a range of
09:56 available available. How do you Uh, that, that occurred naturally
10:02 Earth? So I agree with This would be a large for earth
10:06 . Um, I guess what I'm to is that, um, when
10:11 talk about these sedimentary basins, we talk, don't talk about a
10:16 that is 10 by 20 miles. we're really looking at a much larger
10:21 and that skill you can nicely see , Oh, I think we lost
10:26 we lose her, I hope she's to get back in. Oh,
10:31 she is. Good. We lost . Um Anyway, so um
10:39 they come at a range, And you're right, this is a
10:42 one and there's smaller ones. But , when we talk about sedimentary basins
10:49 are oil producing, we don't talk a little post stamp. You're really
10:54 about larger areas. So that is story that I'm trying to um to
11:01 everybody off here. So do we there's good reserves there? Um That
11:06 aren't being tapped into. Oh, this is in a very prolific petroleum
11:13 and this is being, Yeah. know, there has been a production
11:18 here for a long time. I know about new prospects here. Um
11:23 I do know that this has you know, there's these cities in
11:27 California, in this this valley that basically pure oil city. So there's
11:33 a lot of production here. Petroleum , Bakersfield. Have you heard of
11:40 ? Hayden familiar one of those wonderful in the where you can have a
11:49 in petroleum. Yeah. Drive down street, you'll pass pump jacks in
11:54 all the big buildings. Oh okay, that's really amazing.
12:00 Alright. So while we're staring at map, it's a really good
12:05 So I'm going to point out some things. So yesterday, last weekend
12:10 talked about the Rio grande rift on few times. So I'm gonna point
12:14 out, it's here, that's the ground. The rift, you see
12:23 it starts in central colorado and then extends all the way into New
12:31 So this would be an example of narrow rift zone. We also talked
12:35 about some rift zones that are much . And then I mentioned the basin
12:39 range and I'm gonna sketch the to where the edge of the basin
12:44 So basically starts here. Who's all way up here, All of
12:55 It's the basin and range province. if you look at the topography,
13:00 see these riches here with valleys in those are the ridges and valleys we
13:05 about yesterday and you can see it's after another. So this entire entire
13:11 , the entire, you know, area has extended. It's one gigantic
13:18 rift song. Pretty impressive home. , But for now we're looking at
13:27 for our basins. So, this a figure that you all produced during
13:33 first weekends. And because it is an important figure, um I will
13:39 over it. So, what you here is a burial history. Um
13:46 lower most formation here, it's called basement's basement. Fresh. So basically
13:53 oils, basements and the first sedimentary in this location of the basin was
14:03 at this point in time. So will be the early paleo gene a
14:09 over 50 million years ago. That this formation here. The domain
14:15 So it was a positive from here here. You see that and then
14:19 subsides and then over time it warms so the colors in this figure are
14:28 , any questions about that? Is clear to everybody? Alright yeah go
14:36 . Okay. Trying to kind of a closer look. So the basement
14:44 , I guess you said it was to be positive during the police is
14:48 . Yeah. Um I guess it's kind of a little bit confusing.
14:54 , you can't really see it from but yeah. Okay. Um so
14:59 guess to me like what do we all everything that was deposited, you
15:04 , starting in the Jurassic this So that's a really good question because
15:10 is super confusing. This is basically you put into Patrick. So if
15:16 put into patron malls that you have basement that is 100 and 50 million
15:22 old grenades, Patrons says Okay, gonna put that basement in about 150
15:29 years ago and I'm not gonna, know, I'm not gonna say that
15:35 was a sedimentary basin there but I going to use it as like a
15:41 up before the basin modeling stars. all this is that 100 and 50
15:47 year old basement. That's why this starts around 250 million years ago.
15:53 just puts it down so that it like a basement of rocks before it
15:59 , you know the calculations with um know the sedimentary layers that are being
16:05 on top of it. So we pay attention to this last weekend,
16:12 you could do that in your real model, right? If you would
16:15 this for a company you would think , Okay, maybe I'm sitting here
16:19 a granite basement that was 500 million old and I would prescribe that,
16:25 I would choose that from your list lethality. I would prescribe it that
16:31 wouldn't be present here. And what's only thing that Patrick is going to
16:35 with it? It's gonna say, , I have my basement ready.
16:38 gonna calculate my temperatures and I'm ready start when you're first sedimentary layer is
16:44 be deposit. So it would never your model to do that. It
16:48 fact, it makes it a little more precise because it gives patrons the
16:53 to sort out, you know, was the temperature adepts before the sedimentary
16:59 started to form. So it's it's really good question Hayden and um so
17:05 told this course now for maybe 12 to probably 1000 students and you're the
17:12 one to ask. So that implements this to you and both of actually
17:17 paying a lot of attention to But it's it's a little trick that
17:22 can use and again for us here class, it doesn't matter. So
17:27 pick whatever we want. Right? that is why this model doesn't start
17:31 . Which you would expect. I gotcha. Thank you.
17:35 All right. Now, let's take look at the general subsidence history.
17:41 , we see that at this point time the basis starts forming, the
17:46 starts subsiding. You can see that , right in the geo history goes
17:51 here at this point in time, a phase of very rapid subsidence and
17:59 here it slows down again. Can see the trends? So subsidence extremely
18:05 subsidence and then slower subsidence again. , next question. So, what
18:14 product here is what we call the history or the geo history.
18:24 as you know now the burial history the geo history, they have the
18:29 of the sediment loads included. It's the whole power of settlements, plastic
18:35 process. If I would need to on this figure, a back stripped
18:43 subsidence curve, what would it look ? So that is a subsidence curve
18:51 the effect of the uh settlement it would be less dramatic.
19:03 Which could agree. Um actually formed . So what it would be if
19:14 remove the effect of the sediment load get the tectonic subsides curve and it
19:19 be less deep. Right? We know how deep, but you
19:23 around this time some sub science would . Maybe it does something like this
19:30 here it will be probably rapid subsidence that created the accommodation space and slowed
19:35 again. So maybe something like I don't know exactly what it would
19:39 like, but it would be Right. This here this curve now
19:46 the tectonic subsidence, the tectonics or temperature effect whatever is going on that
19:52 that silence in the basin and everything is the load of the sediments.
20:02 . All right. Now this figure shows temperatures and there's a scale
20:07 lower temperatures I have the bluish colors higher temperatures have the radish colors
20:15 Now, what you see if you one, if you follow one sedimentary
20:20 over time. This one for you see that over time as it's
20:25 deeper, it slowly heats up. ? That's that is as a result
20:29 the heat flow furthermore. You see um around this time here you see
20:38 cold temperatures in the blue colors, being dragged down all the way to
20:43 debts. What's going on there Um Yeah, rapid subsidence. And
20:58 why are these temperatures so cold? there any water bodies or something,
21:08 . There's nothing special going on. just the temperature affected him after.
21:18 do you mean? The temperature affected after. So, you know,
21:22 lays here. This layer here was know the positives. It subsides
21:27 It's very deeper and deeper and it heats up. Same layer this layer
21:33 layer all these layers. You know a layer of sediment is being deposited
21:37 time and it's very deeper and It will start to warm up.
21:43 then we're at this point of And now you see that sedimentary layer
21:48 being deposited here is being very deeper deeper. But there's not much heating
21:53 that's why these isil serves went all way down. You see that?
21:59 is that going on? So they cool down a bit and then it
22:10 hit. Do you agree? I didn't quite catch it. It's
22:18 maybe at that time the plates of tectonic plates didn't have much activity and
22:24 they started. That's the reason I'm that that point of time they got
22:29 a bit. No. Okay. simpler than it's so much simpler is
22:39 ? Because the density increased in the school? No simpler than that.
22:45 , think about this, sediments are deposited that happens every day. Right
22:51 and sediments are still being deposited So are being deposited and over the course
22:56 geologic time they're buried deeper and deeper they warm up. How fast do
23:02 think that warming up happens? It's overnight. It takes a long
23:08 These are sediments that become sedimentary This heat. They are not going
23:12 heat up in a year. It it takes a long time. So
23:16 you bury these sediments very quickly, deeply, they haven't had time yet
23:22 heat up. And as a result that at this point in time when
23:27 was very rapid sub science you basically to sediments so deep, so
23:33 so deep that they didn't have time heat up yet. So at that
23:37 in time, if you would have a hole in that basin where there's
23:41 more four million years ago or so million years ago, you would have
23:45 a hole in the basin. You have drilled very deep and find very
23:50 rocks. So normally subsidence is not fast in sedimentary basins. So your
23:56 have time to heat up and your basin is always in what we call
24:01 equilibrium. However, sometimes subsidence is fast. These sediments don't have time
24:09 heat up. And you basically have whole pile of cold sediments in your
24:14 basin. And that is what you here. And that is why you
24:19 these terms going down so much makes or No. Yes, okay,
24:32 then we see later on, so to the present day, we see
24:36 serves here dipping. You see that hard to see but they're dipping like
24:42 . What's going on there. Mm . It's hard to explain why it's
25:05 . But um, it's kind of that it is warming up with
25:12 Excellent. It's warming up the And um so you see that you
25:18 these reddish colors. Right? So clearly warming up because the versions of
25:23 is here is time. It's not distance. Right? This time.
25:27 , what you see is that in course of time at one particular
25:32 temperatures become higher and higher. And it's somewhat difficult to imagine. But
25:39 answer is correct. This is warming up the sediments. Okay,
25:47 Questions about this plus million years. that when the gulf of California opened
26:00 ? I mean, is there a with that? I mean, I'm
26:02 trying to think, Yeah, I , yeah, go ahead. I'm
26:10 . Let me tell you what the claims and what I think.
26:15 the literature says um that in this of the great Valley there was under
26:24 little sphere hanging a drip. you know, if this is the
26:30 sphere and the top part is the , there are indications that sometimes these
26:37 sphere plates become unstable and they form a drip. They wanna sink into
26:42 animal. A mental. I really that idea please. Well, I
26:47 completely hated. But anyways, people that and they say that for the
26:52 portion of the great Valley where it well, is from something like this
26:58 have happened. So this is who this? And so you can imagine
27:05 you start pulling on the bottom side a tectonic plate, you can pull
27:09 down. And he thinks that that around this time and that that caused
27:15 rapid subsidence. However, when I at this curve, such rapid
27:21 you see only one location on earth that is next to a strike slip
27:27 . So I think that this indicates um maybe strike slip fault forms or
27:35 active around this time in this region would very easily transform Eliphas Feerick's strike
27:44 fault. Right? Yeah. So whole plate boundary is moving inward,
27:50 ? So today, where you have walker name, which is a
27:53 you know, right? So the the course of time that that seduction
28:00 plate boundary changed into a strike So a transform plate boundary which is
28:06 inland basically. And so this is what I think when I look at
28:11 . So i i this is, know, buried below the surface.
28:15 ? So I don't know if she , I don't think he would see
28:19 at the surface of the Great I think this will be buried.
28:24 strike slip fault, one that you know, cuts across the the
28:29 sediments at the top. Um But what the show they're like regional rotation
28:36 all this stuff, including in the basin including the I'm talking Nevada,
28:41 know that basin range problem isn't there some component of rotation in there with
28:46 this stuff going on. Yeah, when you had the subduction zone in
28:50 western us, so when at one in time the sub ducting oceanic little
28:56 was very young and it stuck to overriding plate to the north american
29:01 And when that spreading which offshore stopped , that became one place one oceanic
29:07 which moved in the north westward direction respect to north America and started dragging
29:14 it basically southern California. So if go back to this figure here,
29:20 can see this, the orientation of mountains here is different from everything else
29:26 ? Everything is oriented like this except these. So these are stuck to
29:33 of the micro plates below and are part of the north of the pacific
29:38 and moving in this direction. So exactly what you're saying. Leo
29:47 and now this is a transform fault ? And then here in the east
29:51 have to walk relay so that transform system is moving inland. Yeah,
29:59 I see a figure like that like were showing and you're saying why is
30:02 happening? I try to, I to think about the tectonic processes,
30:07 regional geology that's going on at the time and see if that could be
30:12 as an explanation for what's happening? I think it's a much better explanation
30:18 things dripping off for which there is evidence. So the whole drip idea
30:23 is so the list is too, just occasionally drip off. I mean
30:29 the thing that I don't like about and I think refutes it is that
30:32 have, You know, three billion old bits of crust and electricity are
30:38 floating around. If that idea was pervasive process, those things would have
30:44 chewed up, they would have been would have been dripped off and then
30:48 would create some gravitational instabilities and they have just been chewed up in the
30:53 the in the supercontinent cycle process. I mean I think the fact that
30:57 have like really really old creek tonic spheres floating around sort of refused that
31:05 . But anyways that's just me. . So there it is um it
31:12 a very popular idea so people call a drip, right? The little
31:17 dripping something like that. So I it does not exist that the
31:23 But I have published maybe two papers the topic and people really like that
31:30 . So they're really well cited. I I do not believe in it
31:33 but everybody else seems to believe in . Um So what can you
31:37 Right, may I make another sort side comment if you don't mind?
31:45 be careful about, I mean in case they're saying tectonic sub substance meaning
31:53 that's basically the thermal subsidence. But word tectonic does not necessarily mean plate
32:01 . For example, if you read literature, you know, planetary
32:06 planetary geophysical literature, you'll see that talk about tectonic features in mars and
32:12 the moons around jupiter and Saturn because have big sheets of ice and frozen
32:18 and things like that. So the tectonic just means big regional structuring from
32:26 I can say. It's kind of just be careful once you see the
32:30 tectonic, don't automatically think you're talking plate tectonics. Anyways, I was
32:38 it's basically, you can almost call geology rights, geology or or whatever
32:44 going on rather than just the sediment . All right, let's move
32:55 Okay. I'm not gonna give you example from the center of Australia.
33:03 um so here you can see a of Australia. The little blue box
33:07 shown here and in a little blue , we're gonna look at a small
33:14 . It's basically an an antique Lionel rich structure that has formed traps for
33:22 . So that's where we are. have three wells. I'm going to
33:26 you one of them cuba one Marangi pelican. They're indicated in these triangles
33:32 right there and we're just going to on one of them. All
33:39 Here we are. You're looking here a geo history curve for burial history
33:45 of this particular basin in Australia. is called a cooper basin in
33:50 So, I'm gonna show you this , horizontal access time for records is
33:54 steps. And the first question I'm ask you is, what type of
33:59 basin are we looking at here for for land reflection? Dual rift basin
34:05 apart basin platonic basin. Which one we looking at here? Roasted
34:17 What are we looking at? And could you tell is it? So
34:35 me, my, my kind of first thought is that it's a rift
34:38 because it has rapid subsidence followed by looks like cooling because it kind of
34:44 flattens off. But um, it's a continental learn. So what was
34:52 other name for that mechanism? This a crossbow tag, isn't it
35:00 Creek tonic basin or crystal sec or tectonic basin. And you know,
35:09 Hayden is not, not far off remember this platonic basins, some people
35:14 that they initially start as some kind rift. But how do you
35:20 look at this time scale More than million years. And then yeah,
35:28 ahead. So that's that's the That's the key. And then it
35:37 impressive. Right? The big big picture that fills your screen with
35:41 lot of colors. But look at vertical skill 3.5 kilometers in 300 million
35:50 . That's not spectacular. That must a tectonic basin and maybe this chronic
35:56 started out as a rift zone. , that could be completely right.
36:00 is what you could be looking at . Right. That is a
36:04 faster subsidence face. But it's this skill, You know, 300 million
36:10 , 250 million years and then only km depth. That's the gift away
36:18 . And um, Um, there are two phases where there was
36:22 little bit more rapid subsidence in the and then again here. Right.
36:28 , so they are related to plate . So in 300 million years,
36:34 collides and breakups and that's what you of see in this um, in
36:39 history. Next thing I'm going to about here is the following. So
36:45 haven't really seen it in the example did in class. So that's what
36:48 going to point it out here over time of the formation of this cooper
36:54 in Australia. There were several periods time during which there was a little
36:59 of uplift. Can you point those Maybe around 152? Yeah, there
37:15 one and like 70 or something deep . Yeah, you see that,
37:30 basically literally when you see, you the basement come up right often,
37:38 can see that also at the Those are periods during which this basin
37:45 a little bit of uplift. You that it's not really spectacular, but
37:50 is there. No. Excellent. right. Next question, If you
37:58 at this model results, can you me when the water depth was largest
38:07 this basin? And how would you , you know, maybe 250-300 million
38:24 ago? Because the temperature is the at the most depth. I'm gonna
38:35 no. But we're gonna come back that command, Hayden because it's a
38:39 important command. What would you Meghna? Oh good. That is
38:49 a maximum at 90 or so. actually below 3000 ft. I mean
38:54 m nope, I'm talking about the depths. So by looking at this
39:05 , I can see when this basin covered by a layer of water.
39:12 it kind of our white space at top of the um Okay, so
39:17 of where the rapid subsides the second subsidence happens in the cretaceous.
39:23 So this here is sea level. see that zero. Okay so everything
39:28 this is below sea level. So correct, Hayden this year, this
39:34 a fish. This is water. you see that. So if you
39:40 the zero line here, everything below is water. So what you see
39:51 that the water depth was pretty high this time. Right. Reputation was
39:56 deep water in the U. But also here in the beginning in
40:00 permian time there was a rather deep layer. Clear or not clear.
40:11 here. And I guess what I kind of seeing with it being having
40:16 temperatures around 300 million years ago at depths is because of that rapid subsidence
40:22 your explanation, earlier. there's generally sediments everywhere on the planet basically work
40:30 sea levels extraordinarily high end cretaceous That's why we have so many cretaceous
40:38 rocks, right? Yeah. Well we're at that topic, so we
40:49 a lot of cretaceous oil. Um We have zero petroleum that is from
41:01 works that are older than about 540 years zero. Why is that?
41:11 the rocks might not have been heated ? It's simpler than that. This
41:19 this is a tricky question. That's I'm asking is here. Well we
41:26 sedimentation you know, 800 million years but we didn't didn't come first.
41:32 to do? No organic material, life. So you're not gonna have
41:39 source rock unless you have organic Right? So before 540 million years
41:46 , those you know, tiny single bacteria or whatever they were, they
41:52 do it. So that's why we have older source rocks than that.
41:57 that is something you can always be of. Somebody can give you um
42:03 rock that is 750 million years And it would never have your interest
42:09 There's just not enough organic material prior this time to make anything that's why
42:16 is called. Because the only life . Yeah, so, you
42:22 life started to take off on earth 500, you know, 540 million
42:29 ago. So we don't have any rocks older than that. There's just
42:33 enough organic material presence. And um when you look at the
42:40 you know, the source works on , they come in batches right over
42:44 when there was a lot of the covered with water. So, you
42:48 a lot of lakes or inland seas you have, you know, a
42:52 of life. Right? So you very organic rich shoes. So,
43:00 that's why it isn't like distributed equally the time scale. You know,
43:04 old are source rocks? Our best rocks? Um it's related to,
43:09 know, how much life there basically and how much organic material could
43:13 preserved. So keep that in It's a tricky question. But Um
43:18 is important, you know, you need to think about if if you
43:23 get somebody like this 600 million years has been needed to the right
43:28 You don't have to look at it all because it's just too old.
43:31 wasn't enough life on earth to make a source rock. Okay, so
43:37 uh move on to the temperature So, uh in general, you
43:45 here, the temperatures increase with Right? So you can follow one
43:50 and you see that that one formation increases with depth. So that is
43:56 picture that we've seen before. Um me any questions and remaining questions about
44:04 figure before we go on to the one. Let's move on. If
44:10 want to come back that's always fine well. Okay. Rather shown here
44:20 , racial tr transformation ratio. So would like to explain um this
44:28 So do we have source rocks in basin? Um If so what is
44:33 maturity level of the source rocks? wants to give this a try,
44:39 can find source rocks from 90 or million years ago and I think they
44:47 not. They are in a good because they're not over mature because all
44:53 will be red and there will be oil or gas found. So I
44:58 Yeah. So I would say this a good place but to explore an
45:04 against. I would agree with you question. So you can see the
45:11 rocks here. Right, so the rocks at the bottom are more
45:20 That larger adepts are more matured than source rocks at shallower depths. Why
45:25 that just because of the increasing temperature increasing depth? Yeah. Would you
45:36 ? Yeah. Okay. Next question , about 95 to 100 million years
45:46 . Um The source works Didn't even maturing it one or two maybe started
45:55 about 95 million years ago. Why that? Why do we have such
46:00 long period of time where the source are actually not maturing and then all
46:04 a sudden they all start maturing rapidly 95 million years ago because maybe subsidence
46:12 down and gave him the opportunity to of begin to get to the temperatures
46:18 were required for hydrocarbons. Yeah, before this time there was this this
46:25 slow subsidence rights around this time you subsidence rates increase, it's much more
46:33 and you start to pull these blocks the temperature where they need to be
46:38 order to mature. Alright, let think if I can come up with
46:46 more questions here. Um No, think that's about it. Any questions
46:56 this figure or comments. So is time helping the rocks to get to
47:10 certain temperature to get the rocks Is are there any other factors that
47:18 affect? So it subsides normally? , that's what you need, you
47:21 to higher temperatures sometimes. What could is that there's a magmatic intrusion,
47:31 materials, molten rock writers folks, it can heat up the surrounding the
47:38 rocks. It is not really effective , it's not going to do it
47:43 you in a whole basin and I'm give you an example. So in
47:49 the eastern side of the Rocky Mountains Colorado, there's a basin that is
47:54 the Raton basin? This basin is foreland basin and it's formed by the
48:04 of the Rocky Mountains Now in that basin, that Atone basin was for
48:09 long time at the coastline of a sea. And as a result of
48:15 , there were in the past many . Now these swamps, over the
48:22 of geologic time, they turned into layers. You may have heard of
48:29 . Now when you go from a to a cold layer, your organic
48:34 becomes more mature over time, just the oil. So you start out
48:40 with Pete and then he gets brown and then black and then emphasize.
48:51 may have heard of that intersect. . So you go through this
49:02 Now, what you see in that , there are some um course seems
49:09 are brown coal in which a magmatic has come in. So maybe this
49:16 is the brown coal scene. The seam. The layer of coal magmatic
49:22 came in and it forms like seal that coal layer and then that material
49:30 heated up the coal that surrounds it above and below to exercise. So
49:38 could happen. But it's it is small scale so that you know,
49:44 you have a magmatic intrusion, it the work around it right? But
49:49 not gonna bake it over kilometers and scale, it's just really local.
49:56 in general maturation, you know, petroleum systems happens because you bury your
50:04 deep enough. That's that's the reason locally. Okay, you may have
50:10 magnetic intrusion or something like that that's up the rocks but in general it
50:15 the heat from the subsidence. So that is what you need to
50:21 in the back of your mind and modeling something like this, you're thinking
50:26 the temperatures in the region get high and what you would be looking for
50:31 silence as recent number one. If would just depend on magmatic intrusions that
50:37 be much oil that we would be to get out of the ground.
50:43 an excellent question. Um No. right, let's move on. So
50:52 do you see in this plot? this plot is here, bitter night
50:58 its perfect so percent our own let's eyes reflect its So this is a
51:07 predicted veteran. It reflects its depth , depth, vertical access, veteran
51:13 reflections, horizontal axis. So, just saw in the former slide.
51:18 just gonna go back. Um let's a look at some of the source
51:23 . So we have here the I know what it says and you see
51:32 one of the source rocks and the large as well. Now let's take
51:37 look one of the source walk and know it's not on here.
51:48 No, it's this one here, take a look at these ones.
51:52 these are ones of the source walks if we go back we see that
51:56 are today, the transformation ratio is about here and here. Right.
52:03 would say so maybe 60, 80%. So that would be around
52:13 . And that's also what the veteran reflected indicates. Two veteran eyes reflect
52:18 it's in the oil window would be little bit lower maybe around here or
52:23 . So we're here basically in the window. So what the model predicts
52:27 veteran it reflects since is exactly what saw in the transformation ratio.
52:35 so you should be able to compare um model prediction results now now I
52:41 a question for you what if you have been different reel satellite reflections,
52:48 points and you are given three data and they're here and there is one
53:00 and there is one here. So are your veteran it reflected values just
53:05 back from the lab because your company they drill this exploration while they took
53:10 and they sent a core back to lab to analyze veteran light reflections.
53:14 these are the values you get put model together. The patron model and
53:19 predicted Petro modes values for the veteran are shown on this line. What
53:24 you do wrong ritual model because the are kind of separate right, pretty
53:29 apart. The heat flow was too in your model. Would you agree
53:38 ? Yeah, I think that we got different predictions that we changed the
53:42 . Yeah. So the heat that put into your model was too high
53:47 therefore the veteran reflections values that you in the model were too high.
53:53 I would run a new model developed new model and lower the heat flow
53:57 this line, the predicted line basically on top of the veteran like reflections
54:04 . And then you know that the that you put into the model was
54:07 realistic questions about this. No Right. What we see here is
54:19 and this is again a burial history or a new history curve. And
54:25 is porosity. So the orange colors very low porosity values. The bluish
54:30 are the high porosity values. Tell what you see here. And the
54:38 city decreased with the deeper rocks due compaction, correct? Yeah. So
54:45 deeper the sedimentary layers buried the lower porosity because of compaction. Excellent.
54:52 there's a couple of layers where the seems to be much lower than all
54:56 layers. So for example, this here, right in the more strong
55:00 colors. What could that indicate? mythology, correct? Yeah, it's
55:07 a different mythology. Any questions about figure right Here, we're looking again
55:17 five tonight reflect it's the scale is here. We're looking at blue,
55:24 and red explain this fixture to veteran replicants is maximum at the the best
55:39 and it gradually decreased going upwards Absolutely correct these values here, the
55:51 ones, they basically indicate that you're the gas window. This would
55:58 you know, at this point in your your source works are source
56:02 Didn't really start to mature yet. . It didn't start until like here
56:07 so. So this would be around would probably be early oil. You
56:12 start to mature your source work. really depends on the carriage inside if
56:17 correction starts to mature already or if have to wait longer and then here
56:21 really in your oil window and this be your light oil window. So
56:27 general um oil is indicated with green or the oil window and red would
56:35 the um the gas window. That's people often color these um bars but
56:42 have to say. So Karajan comes different types right? In different compositions
56:49 uh the type of courage in really here. Um so some some correction
56:56 mature earlier than others. Alright, we see a porosity, depth clubs
57:03 I think you all see the relationship . So in general porosity decreases with
57:09 but there are some outliers and that because of changes in uh mythology work
57:16 here we see a figure that shows with depth And it's the same story
57:23 ? In general temperature increases with depth in this particular case you see now
57:30 temperatures are about about 170°C or so the base of this well, so
57:36 is above the oil, window as know now you would be in the
57:40 , window so the gas window would around here now. So this figure
57:48 you present day temperatures in the and so this figure you could compare
57:55 nicely with the bottom hole temperature. maybe when this well was drilled
57:59 people took temperature measurements at the bottom the well, or maybe also in
58:04 places in the well. And so temperatures are often available, so you
58:09 use those as well to constrain the day temperature of your model questions about
58:22 . Um Yes, ma'am, so kind of all these graphs, but
58:26 in particular, um the tr we get to get a really good
58:33 of our source rocks, um but doesn't necessarily give you a visual of
58:41 reservoir rock. Um Maybe I like gone through enough classes yet
58:47 you know, have a good I'm afraid this is a stupid
58:50 but were never drilling into our source , We're always drilling into a reservoir
58:55 . Right, Right, okay. so that is, it's a really
59:00 point. So, um we've been about the source works now because we
59:06 concerned with their maturation. Right? the second half of the story is
59:12 reservoir rock and the trip. So excellent that you're bringing that up.
59:18 the rest of our rock maybe, take a look at this example.
59:25 I'm gonna show you what a potential could be. So a reservoir rock
59:33 be a rock with good porosity and . And that could be a sandstone
59:38 example. So I'm pointing here at sandstone, the Corey Kiana sandstone at
59:44 depths. So maybe that is a potential reservoir rock. Well the rest
59:50 our rock isn't helpful to us unless is kept by a low permeability
59:58 Right. The caprock caprock needs to very low permeability otherwise it's not gonna
60:04 anything for us now. And I'm if I'm thinking that this sandstone maybe
60:10 know from samples that this sandstone has good porosity and permeability. So it's
60:15 potential reservoir rock now is the next . I'm thinking if this rock surrounded
60:22 rocks at a very low permeability and see above it thick mud stone.
60:28 this is present day. Right? we're having here are sandstone layer and
60:34 covered by a thick mud stone. mud stone has low permeability and
60:40 it's a thick layer. So we the potential for it to be a
60:44 solid um cap rock. So this work and then I'm looking here below
60:51 I see here the Now it's very because now we have a low permeability
60:57 above our potential reservoir rock and the permeability rock below. And then
61:05 you can see that over time this base and experience some uplift.
61:10 We see that here, for in here during phases of uplift that
61:15 may have occurred because of a little of compression. So the next thing
61:21 gonna look at is do we see like empty clients in this place and
61:26 riches that could form very nice Now this particular basin is actually a
61:32 with such antique Lionel traps. Gonna back to that just to all the
61:38 to the beginning. To show it . You see, I started out
61:41 this map here of the basin this is the base in the cooper
61:45 And here we have a rich structure the center. You see that and
61:50 may remember from one of your geology that this line here, the two
61:55 going out indicates an anti climb. we have an anti climb here.
62:00 here, one here, one, one there one here. So this
62:05 a a chronic basin that has experienced some compression over the course of
62:12 during which these antique Lionel structures So, let's take a look.
62:20 these anti climate structures they may have during phases of compression which are often
62:28 resourcing in some uplift. So looking this graph many of us compression
62:35 maybe there was compression here. think about the maturation started to
62:42 We looked at that figure that shows the transformation ratios the maturation started to
62:48 around this time here. And it been ongoing ever since now. The
62:55 in that started to mature around these . Around those times we were in
63:05 oil window. Remember that we were the oil wind around this time with
63:10 source rocks here. So oil window correction is mature into oil. We
63:20 a phase of uplift which could indicate during compression. We start to form
63:28 these anti climate structures. Now, you look at this shield, this
63:36 and this much stone when they were , they were deposited in the early
63:43 . So before we had the face uplift, before we had the
63:49 So if we look at this point time when the early, you
63:56 the the carriage in starts maturing into . And that oil face is around
64:04 , we see that we have all of our petroleum system in place.
64:09 have source works that start maturing and right in the oil in. Now
64:14 have rocks in place, the broad shell and the allure of mud
64:20 we have a sandstone in place and we're gonna start compression of phase.
64:27 we form beautiful traps, these empty . So in other words, the
64:32 that started forming at this time it up to shallower depths, it found
64:39 reservoir rock. This sandstone here, above and below by very nice cap
64:46 , a gigantic thick layer above. you're not gonna reach that easily.
64:51 , that reservoir rock and the rock probably gonna stay intact. And we
64:57 empty klein's. So we have the petroleum system in place. So that
65:02 the information that you would get out this. You see that you're looking
65:06 a source work that's maturing. You're for the presence of a reservoir
65:13 We found this very nice sandstone and rocks with low permeability. So maybe
65:18 mud stone or a shell. And we need a track. Well,
65:23 see periods of uplift. So anti may have formed already at this time
65:29 our soils are carriage and starts maturing we have the whole petroleum system in
65:36 and we can start looking for oil this or gas in that recipe for
65:41 . Does that make sense? ma'am, thank you. So,
65:47 a few minutes, I'm going to you two dimensional modeling results of petrol
65:52 and a three dimensional ones from the that show examples of such a
65:57 So, if we go back oops to this figure here, and
66:03 look again at this basin, you these anti clients, let's run under
66:12 . So, if you were an company and you had a couple of
66:15 wells thrills and understood this story. you know now why they are trying
66:23 get seismic reflection data here here, at all these riches, that's exactly
66:31 , where they're drilling. So these , you know, people may call
66:35 rich because it looks like a but it's actually an anti client.
66:38 see that? So this at the of these riches, that's where we
66:47 the oil and that's where we drill the petroleum in this basin. So
66:56 almost um, if you have a dimensional model, Petra molt may show
67:03 where your petroleum may have migrated into reservoir rock. So in one
67:11 it doesn't make one dimension doesn't make sense, right? Because it just
67:14 only move up. So that's why doesn't really do that for us.
67:18 in two dimensions you can really see immigration of the oil. So it's
67:23 excellent question. Okay, does it of quantify maybe how much migration you
67:29 have two? Okay, cool. Let's see, we're almost through this
67:40 I'm gonna go to the next. you guys still okay? Would you
67:43 okay with another, you know, minutes or so or do you want
67:47 take a break now and then come to this? We've been going on
67:52 , um, an hour, five about something like that now or I
68:02 I'm going to listen to one more than you're gonna listen to one
68:06 Okay, very brave. Okay, let's go. So here we have
68:15 let's take a look at the upper , vertical exorcist depth horizontal exercise
68:22 This is the Williston basin which is tonic basin in north America in the
68:27 . S. And Canada. This line that you see here now covering
68:34 with my pen. That is the history curve of the Williston basin.
68:41 pink line here that is the tectonic curve. So burial history curve or
68:48 history curve is again, you know the tectonics that is going on.
68:53 the sediment loads this shallow a curve is just the tectonics. The tectonic
68:59 curve. Okay I'm gonna show you more example. So Patron actually produce
69:06 two plots for you. We haven't looked at them yet but Patrick produces
69:11 for you. Let's take a look the cooper basin in Australia here the
69:16 line again is the burial history curve the g history curve? The pink
69:23 here would be the tectonic subsidence So what you see is that the
69:29 of these curves mimic each other. . But the do history curve or
69:34 barriers to re curve is always much because it has that sediment load
69:42 Alright so how did you go from curve to that curve. What process
69:49 you need to do to remove the load effect. Back stripping back
69:57 We did that last weekend on the remember. Right but the erosion of
70:07 sentiments also look Yes. So in stripping removed, we removed the effect
70:13 the sediment load. Right? And we we got back to that shallower
70:17 right there. Okay. All This is a weird figure. So
70:24 from what produces this, you may clicked on it or you may not
70:27 clicked on it, but just gonna it to you. This is a
70:31 from the Williston basin which is a basin in north America versus mental exercise
70:37 . And take a look at this . This goes back 600 million years
70:41 time. So this is truly a basin personal to exercise time towards the
70:49 day. And what you see on axis here is um petroleum system
71:07 So petroleum is system elements consists of rock, Overburden rock are rock layers
71:17 are shallow depths and they're overlying your system. They have nothing to do
71:22 it. But they're there. Then can see here it says seal
71:28 seal rock or kept rock. So sea work or the cap rock that
71:37 the rock formation overlaying your reservoir basically the petroleum in place and here you
71:44 your reservoir rock here you see a rock line and so we know what
71:51 reservoir rock is in our source rock . And here it says on the
71:56 rock. So under burden rock, are the rocks below your petroleum
72:01 So they could be older sedimentary layers just didn't play a role or maybe
72:07 basement granite rock, anything like anything that's below your your petroleum
72:14 Now then here it says trap formation formation is part of your petroleum system
72:21 because without a track you won't have place to drill for oil,
72:25 You need a trap. Okay here says generation migration and accumulation. So
72:34 petroleum has been formed in your source it may start to migrate out of
72:39 source rock and accumulate in a reservoir . So that is shown there
72:46 It shows preservation and its preservation of in the rest of our rock.
72:53 that is not part of this course petroleum that is in the rest of
72:57 rock over the course of time that rock may be spoiled. So maybe
73:04 reservoir rock is so close to the that ground water starts to flow through
73:09 and it starts to you know, oil or petroleum system, maybe it
73:14 in organic material and it changes the or whatever. But in other
73:20 your reservoir may be completely messed up for example groundwater or it may be
73:25 close to the surface. So preservation the reservoir, that's basically what it
73:31 . And then here it says critical and a critical moment that is,
73:36 talked about it. I think maybe the first weekend or last weekend but
73:40 talked about it at some point in . It is when all the elements
73:44 the petroleum systems are in place and source rock starts to produce oil at
73:51 point in time. You want all elements of your petroleum system to be
73:55 place. When you start producing you want your rest for work to
73:59 there. You want your work to with their, you want your your
74:03 trip to be there and you want migration pathways to be there. So
74:08 is what the critical moment indicates. . Petro Modes predicts gives you this
74:16 output. So it predicts this for . So patrol boats tells us what
74:22 critical moment is at this particular basin at this point in time. And
74:29 you can look, you see by at this figure whether all elements of
74:34 petroleum system were in place and they because you had an overburden rock which
74:42 have protected your reservoir. You had c rock in place. Your C
74:46 was uh and placed a long time , you had your reservoir rock in
74:52 . You see that here in it was placed many years ago.
74:59 had a reservoir, sorry, a work in place. It's shown here
75:03 black. So we had a source . We had an undo burden rock
75:08 is even older than that in We had tracked formation. It's not
75:13 indicated here, But in this particular , transformation started around this point in
75:22 and continued all the way around here had generation migration and accumulation um starting
75:31 this time here we have preservation, have a good overburden rock and this
75:36 a critical moment. So in this case you can look at all these
75:41 of the system and then you can , okay, at this point in
75:45 we start start to mature our Is everything in place from this graph
75:50 could say, yeah, everything is place. Makes sense. Huh?
76:00 . I guess I'm a little confused why couldn't it be maybe like early
76:06 ? Um when you first started, have to have your overburden rock
76:11 Um at that point you still have everything in place. Right,
76:16 So in this particular basin or in different location in this basin. If
76:20 had a carriage and maturing around this , you would have been good as
76:27 . Okay, good point. cool. Thank you. Sure.
76:38 . Um I'm gonna skip this I'm gonna go to this one
76:42 So this one looks familiar again shows . First steps shows a geo history
76:49 , but now it has something else on top of it. It has
76:53 temperature terms plotted on top of And so these ISIS terms are 50
76:59 100 degrees 150 degrees 200 degrees and degrees. So, this one is
77:07 degrees Celsius. This one is 100 50 degrees Celsius, 200 degrees
77:15 250 degrees Celsius. Now, I a mistake because no one was actually
77:22 . So, sorry, 50 100 100 here, 250 degrees Celsius.
77:33 if you look at this isil So, I'm gonna focus on the
77:36 room. This one here, this mainly horizontal with time, writes the
77:44 doesn't very much except for a year then it's mainly horizontal again with
77:50 What does it mean that an ISIS is in this one location in the
77:56 , mainly horizontal over time over such periods of time. What can that
78:09 ? If you would have lived in late you seen, you would have
78:13 a hole here and then if you have lived an early miocene, you
78:17 drill a hole here versus today. start drilling the hole. And what
78:21 you see that the temperature does with increases, increases with depth.
78:28 But the interesting thing is, if would have drilled a hole in the
78:32 , you see this one here, would have found almost the same temperature
78:37 um increase as what you found in early miocene is what you found
78:43 So in other words, temperature depth has stayed constant most of the
78:50 except for around this point of time . So that means that this sedimentary
78:55 has been in what we call thermal over most of its history. Only
79:03 this point in time that we discussed , you see the temperatures were much
79:08 in this location in the basin. an almost horizontal isil term on
79:16 on a geo history curve means the were, you know, stayed almost
79:23 same depth. Right? So a and thermal equilibrium in this particular
79:29 The reason was not in thermal equilibrium this time here because you see all
79:35 a sudden the temperatures were so much in that basin. Yeah.
79:44 Um Okay, let's take a look this 50 years. So the Williston
79:50 is this cra tonic basin in north right here. You see Wyoming for
79:57 north and south Dakota and so that where we are now. So take
80:01 look, take a look at the towards the left. And tell me
80:06 there were periods of uplift in this from a D correct? You see
80:23 400 years, Maybe just after just 300 million years ago here. There's
80:34 more faces, right? There's some and maybe some there. But
80:37 you get it now, how to at that. Right, Alright,
80:42 talk about this last one here. 70 that you immediately picked out 70
80:47 about 30 or so. Do you what happens in North America at this
80:57 ? If you heard of this, lara might. So this is a
81:04 in time when the Rocky Mountains were during this phase, the North american
81:16 was under compression. We formed this mountain range, right. The Rocky
81:20 are a gigantic mountain range. And interesting thing is that that phase of
81:26 of the continent, that responses in formation of the Rocky Mountains even resulted
81:31 some uplift this far into the You see that. So you can
81:37 these these phases of uplift. That at the boundaries of the continents.
81:41 you have continent, continent collision, you you know, whatever is going
81:47 . So earlier on, around here a little bit here and a little
81:56 here. This is when the the coast of the United States, where
82:00 have the Appalachians, etcetera and there a lot of compression there. So
82:04 can feel that those effects can feel often in the entire continent and even
82:10 basin like the villages and basin, is somewhere in the middle of the
82:13 saw some of those effects. So we can relate this back to,
82:20 know, other places in in a where we know what was going
82:24 All right, next question for looking at this figure towards the
82:30 When was the water depth largest? was there was the deepest water depths
82:38 500 million years ago. Yeah, here. Right. I agree with
82:46 . So, originally the water depths was it wasn't a kilometer, but
82:50 was 700 m or so. you see this cra tonic base and
82:55 is a cra tonic basin. I have asked you that first. It's
82:58 tonic basin. You see that generally its entire history, it has stayed
83:04 close to sea level. So, cra tonic basins, they're usually never
83:08 deep there usually around sea level. ? So, with like a
83:20 our deaths would have been measured in versus meters, probably. Right.
83:27 . Well, look again at foreign basins later this morning. Um but
83:33 , I would say yes. foreign land basis, they get
83:38 Right? They get easily to six . So over a short period of
83:42 . Yeah, it seems like the is a pretty good indicator on these
83:47 for rather or not, it's a tonic basin because the create tonic basins
83:52 form Fast. Yeah. So for basis, you look at the time
83:58 . First write a basin that is over, you know, 100 plus
84:02 200 plus million years. That's probably critical basin. So, that will
84:06 the first thing that I would look Many critical basins don't even get that
84:11 over that much of time. This actually does. So this is the
84:15 basin. This one did actually get . But then if you think about
84:19 it took it like 500 million Um you know then it's not that
84:25 . Right, right, okay. , Skip This one. The last
84:37 we're gonna show you example from Anadarko . So this was last weekend's
84:43 right that you're gonna write your petrol about Anadarko basin. So what type
84:49 patient is another occupation? It was basin checking two Foreland basin or flexible
85:07 . So foreland basins or flexible basins form because of loading of the
85:15 right? The loading of the elastic loading of the little sphere in this
85:20 case. These here are depths So the deepest part of the basin
85:26 in the south. So where do think you would be looking for the
85:31 in the north, the east and or the south in in the
85:38 Yeah. And here is our The Amorello Wichita Mountains. So
85:44 that is not an impressive mountain range form more. But it's a very
85:49 mountain range. And when that mountain forms at that point in time,
85:55 acted as a load on the north plate forming this foreland basin here,
86:04 catch a vertical transect through this foreign basin from I'm gonna call this north
86:11 I'm gonna call that south. So do that, let's sketch a vertical
86:16 . So I'm gonna make the sketch , I'm gonna make north here and
86:24 here and the vertical axis here is And I think that these steps
86:33 20 is 20,000 ft 30, etc, 13 ft space in south
86:45 north. Think about it for a . If you would have to sketch
86:50 vertical transect through this foreland basin, would it look like? Who wants
87:25 give it a try? I know can't sketch on the screen. Who
87:29 to give it a try towards the ? Is it deeper? Shallower?
87:38 . Um so it formed like from to right at det, you
87:44 from the left would be greater. . And go up towards the
87:51 So this is the location of the here. The Amarillo Wichita Mountains.
87:56 they have created a deep 40 basin the left side here, the south
88:01 and then towards the right towards the . You see shallowing of the
88:06 you maybe even see something like a or a sexual brooch around here.
88:14 see that central Kansas uplift. Um . Excellent. Alright. So,
88:21 I'm going to suggest is that we're have maybe like a 10 minute break
88:26 so and then we're gonna come back finish this and talk a little bit
88:30 about foreland basins. Sounds great. . Okay, ready to start
88:58 Yes, ma'am. Right. Um let's see where we are.
89:06 , so what I'm going to show next are some two dimensional and three
89:11 patrol boats. So focusing on this a darker basis. Okay, Anadarko
89:17 again. Um, I think most would recognize it as a foreland
89:24 All right. So what I'm showing is the location of um, some
89:31 reflection lines that I'm going to show . So yesterday we talked about seismic
89:35 lines. I'm gonna show you a of them. And so the one
89:39 I'm gonna show you are the ones located here. So they are
89:44 they're almost perpendicular to the um, know, to the loads, the
89:51 range. And they show very nicely the sedimentary layers become deeper and
89:57 The deeper you go into the So, what I'm gonna show
90:01 So, what you see here is following towards the right, you can
90:06 two seismic reflection lines and um, me show you a little bit how
90:16 , how they are oriented towards the ears. To south towards the left
90:22 the north. There's a little bit a kink in that line, but
90:26 shouldn't change much. So, if look at the Orinoco basin, we
90:30 that that mountain range that formed the . A Morello mountain range is located
90:36 . And then north of it. see that, um, foreland basin
90:42 a dark basin, foreland basin with deepest part here in the south and
90:48 layers going further north. Now the reflection line. This oriented something like
90:57 and it's oriented more towards more towards flank of the basin than in the
91:04 basin. So it's more towards Yes, and not in the deepest
91:11 . The deepest part would be around . Now, if you look at
91:17 seismic line at these, the context the sedimentary layers, you see that
91:23 dipping south a little bit. It's a very strong dipping. As you
91:27 see, the flanks of these basins not very strong dipping, but you
91:32 see a little bit of that dipping further towards the south. Alright,
91:39 I'm showing you here is a burial or a jew history plot for a
91:46 in this and an occupation. We're going to point out here where that
91:50 . So this location is around So it's somewhere here at the flank
91:56 the foreland basin. So here it , vertical access on this figure is
92:04 , depth in this particular case it's in meters. So this is about
92:08 kilometer deep location in the basin and exercise time. And if you look
92:15 the time scale, you can see the horizontal axis that it goes back
92:21 , um hundreds of millions of So in this particular case, the
92:28 started forming probably in um devonian or times, just gonna wait till you
92:39 are back because I'm going to ask about this figure. I'm here.
92:48 , that's okay, that's where the . Mechanized back. Right, So
93:33 talk about this basin. So this the Anadarko basin. The Anadarko basin
93:41 a foreland basin and if we sketched tectonic subsidence curve or the geo history
93:47 of a foreland basin, which shade it have as very much rapid subsidence
94:00 for a short amount of time though like this. Right? Yeah.
94:09 initially subsidence is still slow, But then it accelerates and then it
94:14 very complex. So let's take a at this figure here. This do
94:20 curve and see if we can recognize shape anywhere. This shape here.
94:30 it a rift basin? No, a foreland basin. Um Well,
94:40 kind of feel like I see it . Um because around the 500 million
94:46 range, you have slow subsidence and rapid subsidence really quickly and then following
94:53 , you have slow societies again followed rapid. That's upload. Not society
94:59 ? Sorry. No, it's That's good. So, you
95:04 you see this. Right, that well. Yeah, so that's
95:12 These two faces, they show us subsidence of this Anadarko basin.
95:20 I just told you it's a foreland . The foreland basins forum, because
95:25 have this load on the plate. ? And then we are foreland basins
95:29 somewhere here. However, this loads the plate doesn't form overnight. Over
95:35 you see more of these first stacked and then they form a bigger and
95:40 loads and then they form something like . But you often see in foreland
95:45 is, there may be a later of loading as well or some other
95:51 that can cause that second phase of subsidence. So I believe in this
95:57 case that this here will be the basin subsidence and I think that this
96:03 this particular case is caused by some deformation in the basin. But in
96:23 We see that here in the the basin is very deep, 30,000
96:28 , even more than that. So that would be you know 10 km
96:36 deeper in the south and then the decreases going north. Right. You
96:42 that, so you've really this very part of the basin here in the
96:50 . So going back to that that right there um Is it not okay
96:55 start your subsidence curve at 500 million ago or just over? Um I
97:03 that there is some subsidence here. , so you could do that,
97:10 could do, you could start it this and call this slow and then
97:14 rapid face. That's what you Yeah, so that that would be
97:20 to see it like that, You absolutely do that. Yeah, So
97:25 is not a crow atomic basin. this is really a foreland basin,
97:29 this is a foreland basin that started a very long time ago and experienced
97:35 slow subsidence for many periods of time that since around this time 50 million
97:43 ago. But that's not really well . This area has been uplifted a
97:47 bit and today it is above sea . Right? We know that.
97:51 that gives you the subsidence history of Anadarko basin. Now, would you
97:57 the colors on this figure, our and um you see in general that
98:04 terms, so you can sketch some them, right? You can follow
98:08 . They're pretty horizontal. So there really a phase of very rapid
98:12 but there was some going on here this face in time, as you
98:16 see when there was more rapid subsidence it looked like the base and cooled
98:21 little bit over time because the settlements have enough time to heat up.
98:27 in general, nothing spectacular going on . All right now, for this
98:35 basin, I'm also going to show a two dimensional model and the two
98:40 model and Petra modes you can make seismic reflection lines and that is what
98:44 is. So, this seismic reflection , there's a part there as
98:48 It's translated here in a petrol motor that's two dimensional. So instead of
98:54 having one. Well, this is a cross section through the basin is
99:00 southern part where the basin is deeper the darker basins deeper. Use the
99:05 part where the Anadarko basin shallower in this particular case there's a source
99:12 , sorry, a reservoir rock. moral sandstone located here in this tiny
99:18 on the northern part of the Anadarko . And that is shown here in
99:23 little bit more detail. So here see a sandstone which could be a
99:28 rock that is located below the shield also above, assume So, this
99:35 lens here provides us with a, know, this is a reservoir that
99:41 captured on all sides by, surrounded all sides by shields. So this
99:48 be a perfect reservoir rock. when you look at the scale
99:52 this larger longer line, this is 10 kilometer scale, but the detail
99:58 we're looking at here, you can the one kilometer scale. So the
100:03 kilometer scale shows us the details of sandstone lens and the sandstone lenses only
100:09 few kilometers in diameter. Did you that? So it's actually very
100:14 But this sandstone lens has been drilled has been producing petroleum for the last
100:20 years or so since has been really . Yeah, so, it's that's
100:25 area that we're gonna look at in little bit more detail. Now,
100:29 a look at this figure here. figure schematically shows, shows the results
100:35 the Petro mart. Two dimensional model this base in the south side is
100:40 the left, the north side is the right and you see the sedimentary
100:44 dipping towards the side, the So they're deeper in the south and
100:50 slightly thicker in the south now further towards the right here, you can
100:55 again that zoom in of that little mints and furthermore, what you see
101:02 this figure, if you see hopefully tiny green arrows, see the tiny
101:10 arrows, right? These tiny green , show us oil migration pathways and
101:21 there's some tiny red arrows here, example, and they show us gas
101:28 pathways. Okay then you see some things I'm gonna point them out because
101:38 difficult to see. You see here little green line and you can see
101:44 a little green line, those are reservoirs. So those are places where
101:55 has accumulated. Now furthermore, I'm going to go through everything you see
102:04 and then we're gonna go to some later. Furthermore, you see over
102:09 towards the left percentage are all. is that? Veteran veteran it
102:19 So, you see here a line shows 0.4 for tonight reflections.
102:26 and 1.0. So that tells us tells us something about the maturation of
102:32 source rocks that may be in Now, let's first take a look
102:37 the overall picture, The overall picture us in the green arrows formations and
102:44 of oil migration. So you see a lot of migration in this formation
102:50 towards the right and a little bit you see that. But there's also
102:55 here, for example where you have migration that is going down. You
103:00 here going up, going up and going down near towards the right and
103:07 here up. So there's places where was migrating towards the rights towards the
103:13 and going down. Why is Why could oil meat be me migrating
103:19 these different directions? I think that is where the rocks are more formidable
103:33 are interconnected. So the oil is through the pathways, correct? That's
103:40 what's happening? Why is the is oil sometimes migrating to larger depths?
103:47 could that occur? Could it be that brings everything down? No,
103:59 good thinking, but it's not the , is it? Due to density
104:08 ? No. So I'm gonna go now to the first afternoon of the
104:15 weekend. So we went, what had, they will go ahead.
104:20 it related to compaction? Um not directly. So what, This
104:27 the following. So say that this our source rock and our source rock
104:33 maturing. Remember from the first lecture the first afternoon, when the source
104:39 matures, you increase the pore pressure you form this pressure gradient. So
104:46 have higher pore pressure in the source and surrounding rocks and that causes migration
104:51 the oil or gas out of the work towards the surrounding rocks, rocks
104:57 that primary migration can both be up down. So, if you see
105:03 arrows pointing down, for example, it's our shoe and here, for
105:11 , that the source rock above it resulted in some primary migration of the
105:17 out of the source rock into the laying um reservoir rock or lower laying
105:25 migration pathway. Does that make So apart from that petroleum, oil
105:33 gas would always move upwards so it move downwards deeper inside the earth's when
105:39 primary migration from the source rock into different rock. But otherwise it would
105:45 be migrating upwards. Now, let's a look at some of these arrows
105:50 in this formation here, the orange , you see that all the arrows
105:54 pointing upwards. So this is really towards shallow Adepts. Then there's other
106:01 other formations, for example, he a purple one and that is my
106:05 you were just referring to here, can see a lot of migration going
106:10 the right, right. Um so is probably a permissible carrier beds where
106:17 flows very easily following that bed towards Adepts. So that's what you could
106:24 out of this. Now, you in some places, for example,
106:29 you see migration, these arrows are towards each other. You may wonder
106:35 going on. Well, this here like a little antique line, you
106:39 that. So it looks like a just losing my notes here, It
106:46 like the migration there is towards that anti climb. And that could be
106:51 place where there might be possible um accumulation. Now, let's take a
106:59 at the detail here towards the So the detail towards the right,
107:03 is the region that this particular study , the zone that this particular study
107:07 interested in. We see here in , this sandstone lens lens and this
107:14 arrows indicate that from all directions up down and sideways. Um it's likely
107:20 oil has migrated into this lens. see that some of it comes from
107:25 golf, so that's primary immigration. a lot of it also comes from
107:30 from below and from the site. you see that petrol model predicts that
107:34 particular ascent lands um could be a holding oil. Now let's go towards
107:45 shallower depths. So I just mentioned you that we have this green line
107:51 , which indicates a an oil reservoir potential oil reservoir and there's another potential
107:59 reservoir right there. You see Now let's start with the one here
108:05 the left. So you have this oil reservoir. But the ball
108:11 You see a blue arrows, a green arrow. And this green
108:16 points all the way from the reservoir the surface of the earth this year
108:21 the surface of the earth. What that mean that green arrow coming out
108:27 that reservoir? And pointing towards the , I think the gas is escaping
108:34 the great. So in this particular it's oil, right? Because the
108:39 is green, but it basically means the oil is escaping. So this
108:43 a reservoir that is breached. Maybe surface. You know, the permeability
108:48 good enough or the pressure in the got so high that it broke through
108:53 cap rock. But yeah, this is losing oil towards the surface.
109:00 , let's take a look at the here, towards the right. So
109:02 have a similar situation, right? have that green line that can indicate
109:07 oil reservoir, but now we have arrows going into it, but also
109:12 out of that. What could that ? The gas escaping? Yeah,
109:28 could mean the following. It could that gas is joining that Russia for
109:35 when it does that it may actually out some of the oil rights.
109:39 this also means that there were some presence in that reservoir that are now
109:46 . So here we have towards the , we have an oil leak.
109:49 here towards the right, we have potential gas leak. So this that
109:53 look good. So this is the that you can get with Petro moz
110:00 two dimensions. So in two Again, you would put in a
110:03 section, right. Petro moat. then petrol model predicts um not only
110:10 your source rock is, but also your oil and gas may have migrated
110:15 time. And by looking at this , you can immediately see you get
110:19 insights in how oil and gas can in the subsurface rights. What could
110:26 carrier beds? Where could your oil gas have gone questions about this.
110:39 , okay. So I have here little bit more information about other things
110:43 promotes predicted for this line. You really have to, you know,
110:47 at it or so. But if have an interest, uh, please
110:52 free to read it. So, I'm going to show you next is
110:56 , a three dimensional petrol model. three dimensional means all directions in the
111:05 . And then I'm gonna show you afford the results of a four dimensional
111:10 and the fourth dimension only means So when people are talking about four
111:17 , they're basically always talking about three in the subsurface. So really a
111:22 puke in the subsurface. And then first dimension is time. Now the
111:29 that I'm going to show you and have this paper also in the list
111:33 papers that you have is from the basin, just this foreland basin in
111:40 and just I want to show it you because it looks really cool.
111:46 what these people have done and this the USgs actually that has done that
111:51 . What these people have done is have the phillips, a patrol boat
111:57 of the Anadarko basin, which isn't well, you know, we are
112:00 well in class, right. I showed you the results of the two
112:04 model, but they really did the basin just to look at what this
112:09 basin would look like in a petrol . So it's pretty cool. And
112:14 that's why I wanted to show it you. So, I'm just gonna
112:16 you a few figures from their So this is the first picture
112:22 This first picture here shows you a of the Anadarko basin and these different
112:28 show you different depths of this Now again we have in the south
112:33 the mountain range that caused the loads the plate that formed the foreign and
112:38 . So that is the M. . L. O. Uplift and
112:41 mountain uplift. So these are the Amarillo, which is a mountain range
112:45 caused the formation of this foreign and . Now furthermore, you see here
112:50 these reddish colors, the deepest parts this foreland basin. So this is
112:55 the way in the south, right to the load, we have a
112:59 deep portion of the foreland basin and you can see that the foreland basin
113:03 shallower the further you go away towards north, the northwest and the
113:10 So you get that the general idea the depth of this foreland basin?
113:15 , ma'am, I actually have a with regards to the well, that
113:19 that we're studying and doing a paper it mentions in it mentions that it's
113:25 the northwestern region of the Anadarko but um doesn't really make sense to
113:32 because to me it looks like it's the southwest. Mhm. Oh,
113:37 know what? So you are actually right about it. It is
113:45 Mhm. It's like somewhere here, the location of that. Well,
113:51 so I agree with you, I call that the southwestern or western part
113:56 the Anadarko Basin. And the reason it's called Northwest in that exercise is
114:04 other people in the literature referred in past to this region being part of
114:09 north western part of the Anadarko So, it's just because people used
114:14 name it like this, but I agree with you. If you would
114:17 look at it, you would call the southwest. Yeah, so,
114:22 not somewhere here, it's it's it's in this area here, and
114:26 is the very close to the exact . Yeah. So what's important for
114:31 exercise to know is that you're not the deepest part of the basin,
114:35 , that's here, you're basically on flank of that foreign land basin.
114:45 , all right, so, what looking at here is something else.
114:50 , it's also the other day. , I'm just gonna go back this
114:54 the deepest part. Now, the figure that I'm showing you this figure
114:59 at the space in from this So, if you would be standing
115:05 and you would look into this you would see the deepest part the
115:09 away. And then maybe you would these these these mountains and that's what
115:14 see here. So you're looking here the Anadarko basin this year is the
115:19 part and then again here is the of the well approximately of our
115:27 So now North is here and south here. Do you see that,
115:31 that make sense? Yes, Alright. These yellow lines, their
115:38 that are present in the crust. um so we're not going to go
115:42 those but just to give you an of what they are. And
115:45 this is the deepest portion of the . Alright, so here are shown
115:52 fixtures with a similar setup. So is the deepest portion of the
115:58 Let me change that. Um this here is the deepest portion of
116:05 basin, sorry here and our will somewhere here here. So north is
116:13 here in South is here and we're into that base. This is the
116:18 , the figure to register left 220 years ago 220 million years ago is
116:24 time that many of the source rocks maturing in this basin. So what
116:30 this figure towards the left show you first thing that you may notice are
116:35 these green lines. If he it's not really that's clear here.
116:43 more clear if you look if you on the paper but you see those
116:47 streets, right? Those green they show you petroleum. So oil
116:56 pathways. So that shows you where oil that was formed around this time
117:04 migrating to. So it's clear it's out of this deep basin towards the
117:10 . You see that towards here towards , towards here towards here and towards
117:16 and also further out. So these pathways and you were asking about that
117:22 this morning, they can be very , you're talking about hundreds of kilometers
117:28 oil migration in some of these Yeah. So out of the deepest
117:33 of the basin all the way onto flank into the northern portion of Oklahoma
117:40 into texas. Now this picture shows else. It has these colors overlaying
117:46 it and they show you tr what T. R. Again?
117:52 transformation, transformation ratio. Yeah. if you look at T. R
117:59 here, so they go all the from 0 to 1 hundred's. And
118:04 um the transformation ratios that are in region of interests are these ones
118:11 So the very dark blue and purple , they're getting into the gas
118:17 But the oil face is you know you see the greenish colors, the
118:21 colors and the red colors. So can see that at this particular point
118:26 time, we see a lot of here on the right side, you
118:32 hardly see it. And also here the flanks of this basin. Now
118:38 take a look at the picture towards right, it shows the same,
118:42 now the present day. So in present day you can see there's still
118:46 lot of oil migration out of the onto the flanks and into the shallow
118:54 of the basin. So even today have oil migration furthermore, you can
119:00 again, places where these source rocks producing today. So some of that
119:06 in this part here production, but also still production going on or
119:13 I have to say of oil and on the flanks of the Anadarko
119:18 So this is still a system that developing, started hundreds of millions of
119:23 ago and it is still ongoing. also here, you haven't can get
119:29 idea of these migration pathways. So of them are short, some of
119:34 are very long. So these migration , they can be, you
119:38 hundreds of meters and they can be to over 100 km or so questions
119:47 this. No, so this is petrol, the petrol model will do
119:53 you in three dimensions. So you imagine you can really get an idea
119:58 what happens with this oil and where did it end up? Where
120:03 the rest of our works today and it would be drilled. So I'm
120:08 this figure one more time, but in a map, few. So
120:13 is the same figure and this is present day situation. So here in
120:19 south we have the deepest part of basin and then we were located like
120:26 , this is the location of our . So take a look at these
120:29 migration pathways that are shown you here green. So, you see,
120:35 know, some of them are fairly . You see that these pathways are
120:40 long. These are fairly long, are shorter. So in our area
120:45 have some that are shorter, you that the shorter ones here as
120:55 So some places shorter, some some longer. But you also see on
121:00 map few. What this author is author indicated some oil accumulation places and
121:07 indicated here with these green dots or areas. So these are major oil
121:15 in this basin that can be drilled and can be produced from questions about
121:26 figure. So, you can imagine if you are working in a basin
121:34 group as an oil company, that could be the work that you would
121:37 doing for a certain sedimentary basin. you would start with a one d
121:42 , right, if you don't have data available just to see if there's
121:46 potential here, then maybe you would that out to a two dimensional
121:51 If you have a vertical cross section reflection lines for example, or a
121:55 of wells. And eventually you might able to build a three dimensional model
122:00 you see here. Any questions about ? Right? So what I'm showing
122:16 here is the same figure again. then it has a lot of pink
122:22 and black triangles. These pink circles black triangles. These are wells,
122:28 see that horizontal wells are indicated with pink circles and oil wells are indicated
122:36 the black triangles. And you see are still, so some of these
122:40 tipping into these but there are still of these potential oil reservoirs that haven't
122:47 explored yet or are not produced from . Pretty impressive, huh?
122:56 All right, okay. I'm gonna sharing this and then we're gonna talk
123:03 little bit more about four land basins and um don't safe and then we're
123:13 have a break. So what I to do, I need to just
123:19 need to open up a difference. different documents this one here and I
123:32 I won't be able to sketch on . So, I'm also going to
123:35 up another power points. Okay, case we need it. Okay,
123:52 what I'm gonna share with you is answer sheets um of the foreland basin
124:03 that we started to work on in first weekend and let me know if
124:07 can see it. Yeah, So this ring a bell? Yes,
124:15 . So I also emailed to this sheets because this is not really,
124:20 know, it's, it's more difficult see here. Um But what I
124:25 to do is in the next 15 or so if you go over this
124:30 , so, um, if you to take a minute and pull up
124:34 exercise from your notes or your let's take that minute because it may
124:39 easier for you to take notes um you know, take notes on
124:44 on your pdf or however you want do it. So, um,
124:48 me know if you want to pull your exercise and we can take a
124:59 . So this is going back in quite a lot. I've got mine
125:06 up, I'm ready when you guys ready. Okay, So before we
125:15 , let's talk about foreland basins. , can one of you explain to
125:23 in words how a foreland basin forms should do with um there's continental
125:42 I think it be continental and oceanic well. Um, but when that
125:48 , you create like a mountain belt then um, you know, you
125:53 of create a basin at the foothills that mountain belt, correct? And
125:58 does that basin form there? So all, that's all perfect and why
126:02 the basic form there, you remember app formed by the volcanic card,
126:13 the loading of the plate? that mountain range that you form,
126:17 falls through spells. That's a lot mass. You put it on top
126:21 the plate and the plate starts to and ATF lecture of the plate then
126:26 the foreland basin. It's been a , huh? The slab which falls
126:36 into the landing way, Let me it, let me just see if
126:41 can pull it up. Okay, just quickly going to stop sharing and
126:45 we need to go through these foreland again anyways today, so why don't
126:49 try to find where they were wondering they're in here. Open it,
127:14 , Yeah, I'm gonna share a um slide show you he's from
127:27 Alright, so let me know if Yeah, right, so there we
127:36 , so we have a continent, collision zone forming this mountain range and
127:40 nice example would be the Himalayas. another example could be the alps in
127:46 or the Rocky mountains in the United . Now this mountain range acts as
127:51 load on the plate, that's a of mass and as a result of
127:55 , you will get some flex chewable working here and also over here and
128:03 is where these foreland basins form. we have a foreland basin here and
128:07 foreland basin there. You see that would be forming right there and right
128:14 . Does that ring a bell Alright, so that is what we're
128:19 at here. So, we're looking a foreland basin that forms basically at
128:23 site of a large mountain range, as the alps, the working mountains
128:29 the Himalayas. The mountain range doesn't have to be that large. You
128:33 also have smaller mountain range that forms smaller foreland basin. But this is
128:38 to give you an idea. All , let me stop sharing this one
128:43 go back. Well, let's Okay, let's let's just go back
128:51 some of these flights. So, now back at understanding where these foreland
128:56 form. So, these foreland basins sometimes called Flexeril basins. Right?
129:00 this is a sphere behaves elastically on time skills. And that means that
129:05 investigators very plate bands or flexes under loads. And that was what was
129:11 flexible. So here we have the . This is a very schematic mountain
129:16 , as you can see. And we have the little stick plate or
129:19 elastic plate that is bending on the of the lobes here and here are
129:29 where sediments will be the positives. this will fill up with settlements and
129:33 will fill up with sediments. And , this is where we form the
129:41 basis. Questions about this? ma'am. All right. So,
129:50 this elastic plate was sick, what that do with the deformation of the
129:58 ? So we have two situations a elastic plates and a thick elastic
130:04 Here's the thin one With the load here's the thick one with the
130:12 Both cases, the load is the , but in the left case the
130:16 plate is thinner. In the right the elastic plate is thicker. How
130:22 the deflection of the plate? Different these two scenarios with the thicker elastic
130:31 , you'll have a shallower um basin it might be wider or thinner.
130:37 , it'll be deep but narrow. you agree? Okay, great.
130:43 me sketch that in then. It's schematic, right? But you get
131:03 point. So you're absolutely right. elastic plate means you're foreland basins probably
131:09 but much deeper. Sin in a elastic plate means you're foreland basin is
131:14 much wider, but also not as . Yeah. Excellent. Alright,
131:21 we indicate the sickness of the elastic , often with E. T effective
131:26 thickness or t thickness of the elastic . And effective elastic thickness can be
131:33 like 20 or 30 kilometers that would rather thin but it could also be
131:38 kilometers or 80 kilometers. And that be rather thick. Just to give
131:42 an idea. Now we also talked fletcher of the little sphere or deflection
131:49 the little sphere where elastic deformation of little sphere. And then we talked
131:54 this equation. So this elastic deformation the little sphere is described by this
132:00 order differential equation. In his fourth differential equation he had on the left
132:07 , the rigidity of the plate and rigidity of the plate was dependent on
132:11 effective elastic sickness. Age. So sicker, the elastic plate, the
132:16 rich at the plate is and the resistant it is against bending.
132:24 In this equation is the deflection And we know now really well that
132:30 this deflection as this shape. It's 1/4 order differential equation. So
132:37 has a very deep basin and then it has like a little broach and
132:42 it has a tiny back coach. . So that is the shape of
132:47 foreland basin system. And towards the , we have this term here delta
132:52 rho mantel minus roll sediment infill or infill. And this is something.
132:58 if you are putting a load on plate and the plate is bending down
133:06 plate doesn't sink through the esteem a or so something pushes it up or
133:11 it up. And that term is here. Q. X. Does
133:17 remember what Q. X. Was in this equation? Think the Lord
133:28 is being put on the plate. . That's the load. So this
133:34 is Q. But if this is X. Axis, you could say
133:39 that loads varies as a function of X axis. So we write loads
133:44 function of X. So maybe in case of a foreland basin, there's
133:48 very high mountain range here, there's here and there's less here. So
133:54 loads may vary as a function of . So that's why we say
133:58 X. Yeah, so that's the . Excellent. Alrighty. And now
134:07 well let's do this one and then go to the exercise. So what
134:13 looking at here is a little bit detail of such a foreland basin
134:17 So the full first belt is here the left, this is the two
134:23 it. And then uh you this all is continent and I think
134:29 remember that. Right, right, , so the 40, that's the
134:40 part of the foreign land basin. sometimes people call that the four land
134:45 in the 14. So it also that shape, right, its deepest
134:50 to the load and then shallower further . And then when you look out
134:54 , you can see that for brunch then here the tiny back porch
135:00 recognize it all right here towards the , we have like some feed some
135:08 coming out of this 4th 1st belt are basically present here and on top
135:14 that area of that wedge we can wedge top basins. So you see
135:20 here for example, this would be a ridgetop basin. So together this
135:27 up for a foreign land basin So we have basins on the wedge
135:32 , we have basins in the four , we have bases on the four
135:36 , maybe, or sometimes the four , higher elevation and erodes. And
135:41 may have a little bit of sedimentation that back roach area. But the
135:46 deep again is our main basin. did the sediments come from again that
135:53 up a sedimentary basin here? Uh thrust belt. Exactly. So they
136:01 come from this area here. The higher you build up your fault
136:05 , about the more sediments you create the more settlements are being transported into
136:12 four deep basin here. Yeah, . Okay, do you remember
136:19 what is the typical depth of a invasion? Um I don't remember the
136:40 Of kilometers, right, two 6 km, maybe eight km,
136:46 like that. Yeah, This system be very wide. This can easily
136:53 600 km or so, so it be a fairly wide system and it
137:00 also be elongated. Right, If mountain ranges elongated, your basin will
137:05 elongated as well. So this can large sedimentary basins. Right. Questions
137:16 this. More questions. Okay, , I'm quickly gonna start with that
137:25 and then in a few minutes we're have a break and we'll continue after
137:31 break. Let me try to find . Yes. Right. First question
137:41 you. Um that figure that you here at the top of this
137:46 Where was it from? Do you India? Right, nope. I
137:56 know. Um You can see it , but that's uh you know this
138:04 basin in there, that goof in , The Middle East. Yeah.
138:10 this is the Persian gulf, So the Persian gulf again is a
138:15 basin. So the southern portion of foreland basin is covered with a layer
138:21 water. That's the Persian gulf. northern portion, I don't know if
138:24 can see my curse about. The portion is filled in completely with
138:29 The Zagros Mountains, which are a range in Iran. They form the
138:36 of this foreland basin. All now, let's take a look at
138:40 exercise. So the first question says . The information of an elastic plate
138:45 a line load is described by the equation. So we know that
138:49 Right, this is a first order equation. Remember about the functional
138:54 Was it was given by this And this equation E is the Young's
139:00 and New Year's ratio. And those elastic parameters. So they tell you
139:06 about how your work response elastically to information. So those are constants.
139:13 here is the is the flexion W. Is the deflection of the
139:18 . Roll em is the density of mental or fail? Is the density
139:21 the basin fill material and Q. . Is the load. We just
139:26 that. Now every equation has a solution. And the solution to this
139:31 is given by the relation below As a function of X. Over
139:36 equals W. Max my time sometime exponents times so a term that has
139:42 co sign and a sign in In this equation of of us to
139:48 your wave number in meters given by relationship over here. And if you
139:52 at this relationship in more detail, see that it has again the Flexeril
139:57 deemed in it, it has a role in it. And delta rho
140:01 the density of the mental minds density the infant. The actual wavelength is
140:08 pi times alpha. And again, is given in this equation here.
140:15 first question for you is looking at equation. I hope you can see
140:19 . Maybe I should try to enlarge a little bit. Yeah. Here
140:27 is enlarged. All right, Maybe I can make this go
140:34 Yeah. So let's take a look this. We have alpha which is
140:39 the wave numbers or the wavelengths comparable the wavelength we have here a relationship
140:45 alpha and flexible rigidity. D take look at this relationship. The larger
140:54 Flexeril rigidity of a plate. The plate, elastic thickness is you can
140:59 that an equation over here. And is gonna happen with alpha is also
141:09 proportional to the be. So, think they are they are all connected
141:16 . And if one increases all of increased, that's exactly right, that's
141:21 . So in other words, if have thicker elastic plates, you have
141:25 higher rigidity of that plate. The does not want to bend easily.
141:30 therefore you get these deflections, these land bases that are wider. They
141:36 a longer wavelength alpha and less That's exactly what's going on. So
141:42 can get that out of this You see that? All right,
141:54 number one, How does the flex wavelengths all far relate to the elastic
142:00 of the four land plate. what you basically do? You can
142:04 about it or you can calculate. let's first think about it.
142:09 the flex dual wavelengths. That equation shown here, and it showed this
142:15 with the Flexeril rigidity in it. Flexeril rigidity again, in turn,
142:20 a function of these parameters here. , if I decrease the elastic plate
142:29 , age, what is gonna happen my factual rigidity? It's going it's
142:37 to decrease as well. Right, . So if we decrease our ballistic
142:43 thickness, we decrease the actual And the D. Goes into this
142:49 here, that has often equals If I have a smaller flexible
142:54 D what is gonna happen with my ? It will be smaller, it
143:00 be smaller as well. You Right. Yeah. So in other
143:04 , let's go to question number what is the relationship between the Flexeril
143:10 and the elastic thickness of the foreign plate? Well, the smaller the
143:15 sicknesses, the thinner the elastic the smaller the wavelength of the
143:20 So you end up with this deformation foreland basin that is narrow but fairly
143:26 . Yeah, the larger the elastic of the four land plate, the
143:31 deflection rigidity, the more resistant to the larger the wavelengths. So in
143:36 words, if you have a sick plate, you will form a broader
143:42 wider but less deep foreland basin All right. So, what I'm
143:53 do before we continue with this let's have like an eight or 10
143:58 break. And then we're gonna continue this. Okay, Sounds good.
144:03 gonna stop sharing now, and I'll you in a few minutes.
144:13 Alright, let's get started again. , we're talking about this foreign land
144:20 rights. Next question in this exercise you sketch below deflection W as a
144:27 of X. So at 0.0, can calculate what the amplitude of the
144:34 is. There's an an equation for that you can see here and then
144:40 shape now you've seen many times right the deepest part of the base and
144:44 to the loads. Then here's the boat. Here's the back boat which
144:48 a tiny base and etcetera. Questions this. All right, then you
144:58 a dash line here also with a . If you compare the dash line
145:04 the solid blue line, which one these has the higher flexible rigidity and
145:10 thickest elastic thickness. Is it the line or the dash line? The
145:17 line? Would you agree? So again you have a smaller amplitude
145:25 deflections and you have a broader The next question as you show what
145:32 relation is between the deflection near the the front of that mountain range and
145:39 flexion rigidity. So we know already you're flexible rigidity is higher, you
145:45 a base and that is less So w the deflection at this location
145:49 will be less. Or you can show that with equations you have an
145:54 for this deflection at 0.0 X So that's the toe of the mountain
145:59 , which is this equation here. then we can plug in. That
146:04 is all file which has the Flexeril . And that gives you then the
146:10 between um the amplitude of the deflection um the reflection reflection rigidity and the
146:22 of the deflection. Any questions about ? All right, Okay.
146:32 We already did. And then this is more complex. And I first
146:38 to ask you if you have been to do anything with this last portion
146:43 the exercise, that's what I felt about. Like this one is actually
146:52 straight, you just have to substitute , I was about to ask you
146:58 I didn't feel confident about it. , So what I want to
147:04 let's go over the most important points and some of it we've actually done
147:11 . So there's some kind of start this question here. So there's,
147:16 know, here we have the deflection , right? There's three points scheduled
147:23 here, point number eight, point B and point number C. And
147:28 this question asks us, is to sketch how these points go up and
147:34 over time as this flex, dual moves over them. So remember from
147:41 first weekend, and when you have foreland basin, that foreland basin is
147:46 at the same location over time, kind of moves away from the of
147:51 moves with the mountain range as the ranges growing. So this system by
147:57 moves and this was something we started in our first weekend. It is
148:02 concept that is not easy to but the basic ideas is when you
148:08 a mountain range, that mountain range upright, it becomes higher, but
148:13 also becomes wider, so it kind moves forward as as its its
148:21 So that means that the foreland basin move forward as well, that's the
148:28 salt here. So what I'm gonna is I'm gonna open up the power
148:33 point with some free slides and then gonna sketch this one on the power
148:38 . And so I'm gonna stop sharing one and then I'm gonna open up
148:43 open power points if I can find here. Right? So here it
148:55 . Um So we had that curve the deflection doing this right? And
149:04 you have several points on that Um Let me see where they are
149:10 I don't remember by heart points eight us here, Point B. Was
149:19 and Point C. Was here. A. B. And C.
149:24 remember over time this mountain range that see here towards the left continues to
149:32 and therefore it will move in this , right? It will take over
149:36 of that space. So that means this flexible information, that wavelength moves
149:42 the right as well. So the step it will be here. You
149:47 that right? That's the concept. , so let's take a look at
149:55 um this exercise then it has on horizontal excess time and on the vertical
150:04 it has steps. I'm not gonna all the access because she has the
150:11 . But um this is what it like. So what's the question is
150:17 does point A do over time, does point video over time? And
150:21 this point see do overtime? So A. It's located here,
150:32 It has oh sorry, let me that a little bit better. So
150:38 A. Is located here. So or at the start of our exercise
150:46 is located the slightly below zero. is zero level, so it's slightly
150:53 . So maybe it is located here we start looking now going now forward
150:58 time, this mountain range is gonna and the load is gonna move in
151:03 direction. So what is gonna happen print A. Going forward, Point
151:09 . Going forward will become part of deeper basin. So going forward,
151:15 can say that Point A. Is do this, would you agree?
151:24 then let's take a look at Point . Today, Point B.
151:28 Is on that factual broad shots So it is it is located somewhere
151:35 . Point B. What is gonna over time? So over time when
151:41 mountain range moves towards the right, is gonna happen with Point B.
151:46 gonna go up or down down, maybe it was not as quite a
151:53 slope as point A. Would you ? All right, something like
152:04 Yeah. How about Point C. Point C. Is located on the
152:10 of the brooch currently at zero So this is the starting points of
152:16 C. What is point C gonna over time? It's gonna go
152:26 would you agree? Yeah. So think it's gonna go up first and
152:32 when it comes to the other side the brooch it will go down and
152:36 this curve Grief, we're not that was this exercise. I'm gonna
152:51 sharing this one quickly, go to other one and then we'll come back
153:00 . Here we are. Alright, that is shown here and you have
153:07 answers, right? So the starting for B. A. And
153:11 Are shown towards the left and I these curves here so you can see
153:15 better, but they should of course there. So that is exactly what
153:18 just did on the board. Alright , the last question, So if
153:29 look here at POINT C, Point started out at zero and then over
153:34 it became part of that brooch here then it goes down again when it's
153:41 the butch this material will start to mountain ranges, erode whatever is above
153:47 out is going to erode. So in other words, when you
153:52 eroding that material, you remove it then later on you would bury you
153:57 . You would recognize it as a graphic gap or as an nonconformity Yes
154:06 no. Yes ma'am. Yeah, this we erode this off.
154:14 So if you would know how fast C would move. You could calculate
154:21 duration of the strata. Graphic you would basically look at,
154:26 this is first one, it's gonna up. So now it's when erosion
154:29 gonna start, it's gonna erode here here here here, it's gonna dive
154:35 to below zero or whatever. And is going to stop. More sediments
154:40 gonna be added on top. So here represents a time gap not only
154:47 stuff, missing rocks but also a of time during which that was
154:53 And you can calculate the duration of time gap. How would you do
155:05 by calculating the wave number or the difference between them? Your clothes,
155:17 clothes. So, let me first with very simple physics that you both
155:24 . So remember the creation as distance velocity times time. Right? So
155:33 what you're gonna use. So you to have time, right? So
155:35 switch around the creation Time equals distance philosophy. Now we know the philosophy
155:42 it says the advance rage of the registered millimeter per year. So the
155:48 unknown is the distance, but you calculate that distance from here to here
155:54 that um alpha. Because this here like half the wavelength. So you
156:01 this distance, you know, the 10 per year. You calculate time
156:07 or time gap equals distance over And then you have your time
156:15 Right? So in this particular um the time gap four point C
156:21 if you do the calculations right, 26 million years point B as you
156:27 see also has a time gap because right at the top of the
156:31 right? So the point be time is something like 10 million years and
156:36 a would not have a time gap it's underneath, you know it's it's
156:40 00 C. Level the whole So you understand you could calculate that
156:47 the duration of that gap because you the distance, you know the
156:51 So you can calculate it now. that information is used for the final
156:59 here and the final exercise here. is this is complicated, This is
157:05 grown Australia graphic diagram which are difficult read but you will see them in
157:11 literature. So many companies do work them and they're studying a sedimentary
157:17 So what does this show you the axis is time in millions of
157:23 So going up, you know in , the horizontal axis is a distance
157:30 you could see it as the distance from for example the what we call
157:35 origin it reg or the load, ? The load of the mountain
157:40 So horizontal axis is the distance, axis is time. So this is
157:43 complicated plot. So what I've sketched towards the left is how this mountain
157:51 grows over time. So you can that the mountain range increases in the
157:58 X. Over time. It basically the growing of the mountain range over
158:04 . Is this clear this line or ? Um Do you mind repeating
158:13 Yeah. So but this shows you part here. This is taken up
158:18 the mountain range, we call it wedge. But you could call it
158:21 mountain range that fought first Belt. the first belts grow over time,
158:26 in height and laterally. So they up more space over time. In
158:31 particular case, the fault First belt growing between zero year zero and 40
158:39 years. During that time the first was growing, It was growing out
158:44 it was growing out as you can indicated here at 40 million years.
158:50 fall first belt stopped growing. So there was no longer continent continent collision
158:54 whatever what was going on, It no longer growing. So it's no
158:59 going further towards the right. All right next to the falls first
159:07 we find the foreland basin and that basin is sketched here. This space
159:13 , I hope you can see my , this is the foreland basin.
159:19 it's the right of the foreland We find the four broach the four
159:24 , is that, you know, little bit higher area outside of the
159:29 basin. That for Butch is shown that just so I can form a
159:36 graphic gap or a nonconformity. if that four broach is eroding,
159:41 erode away that material and that is you see here. So in other
159:47 , we only have the foreland basin between that mountain range and the four
159:54 in between is where you have your . Does that make sense or
160:00 Yes, ma'am. Right now, see here, this points A B
160:05 C. Again, C was located away from the 41st Bells be closer
160:11 A was located initially within that Point C. We calculated that the
160:18 graphic gap was about 26 million years duration and that is what I've indicated
160:25 . This is the location of Point . This here is the strata graphic
160:30 . So, this is the four on conformity. Point B was initially
160:36 almost on top of that four vote . We calculated the duration of its
160:41 gap. There was about 10 million and I put that in here And
160:46 a was initially located in the So there's no strata graphic gap
160:51 Now, I simply connected these points million years, 10 million years,
160:58 it like this. And then this here towards the right, gives me
161:02 location of the four votes over time because the material is eroded, we
161:08 it the four votes on conformity or four votes strata graphic gap over
161:17 Right. So, would you both that between the four Belch and the
161:23 range? We have the foreland All right now, remember.
161:29 this is from the first weekend we about these foreland basins when they initially
161:34 , we don't have enough sediments available fill up this entire basin. So
161:39 call those basins under field basins that under filled and in connection to an
161:46 or a C. They will be up with sea water so they will
161:50 marine. So during the under field of a foreland basin, you can
161:57 marine sediments in your foreland basin and is what you often see in these
162:02 basins. They start off being under and if you would look at what
162:07 are being deposited at this stage, would find a lot of shields marine
162:13 . Now then, in the course time, as your mountain range rose
162:18 and bicker, you form more and sediments and you will be able to
162:24 fill up your foreland basin. So other words, the water layer becomes
162:30 and shallower. We call that shallowing and eventually your entire basin will be
162:37 with sediments. So we go in sedimentary basins for marine sediments,
162:41 etcetera. Then you go towards shallow , then you go towards coastline and
162:48 you may go to continental sediments of feel sediments, for example, does
162:52 make sense? So in a groan strata graphic chart that is the information
162:59 you would put here on the you would probably find shields shallowing
163:06 Maybe some seals and sense? Then start to come in the coastline
163:11 So maybe you find even evidence for tunes, some deltas maybe. And
163:16 eventually you get into an environment or is about sea level and we find
163:22 that are coming off from these mountain . So they may be conglomerates,
163:27 feel sediments, anything like that makes or no. Alright, anything unclear
163:38 this man. Okay, I'm gonna sharing and um this one can go
163:49 so that was that exercise and then see if we can do a few
163:55 things and then we're gonna move on to four basins and sharing this and
164:02 to go to the next slide. , katanec basin subsidence curve except rift
164:23 scarves, that rift. So let's do the active rift here.
164:29 , sorry about that active rifts of cruise. We make this present day
164:37 here is present day, this is sub science curve. This is a
164:43 drift subside and scurvy. Now I'm sketch the foreland basin subside and
164:56 So this is the four lands, is the, this is a rift
165:02 is filled, This is a rift is active. I'm gonna sketch a
165:07 that margin and then this one here creek tonic questions about this.
165:27 So if I give you something like , you will recognize it,
165:31 You will be able to label a like this. Okay, so foreland
165:39 , you have it in your mind forms next to a mountain range is
165:43 the rocky mountains, the alps, Himalayas or smaller mountain ranges That will
165:48 fine as well, rift zones form stretching an extension of the little
165:53 Sometimes these rifts die out. They we call that by the way our
166:00 region is a field rift arm. may find that term one day we
166:09 the script on IQ basis. Those are the old basins on the crypto
166:13 old parts of the continents. And we have the rift id margins now
166:17 next one that we're gonna add to A four Arc basis. And then
166:27 lunch we're gonna add the pull apart or the strikes basins. No,
166:41 can't give something away ahead and go . So with the foreland basin that
166:47 illustrated um is it not normal for for them to normally like, I
166:54 know draw the line to present day with no subsidence, like just two
166:59 on the line from there. you could do that absolutely like
167:06 So that would show that you're for based and forms, you know,
167:11 these stars and since then it has been sitting there. Yeah, you
167:16 absolutely do that. You can do with all these curves right, this
167:20 base. And you could say, , nothing happened after that.
167:23 So you could absolutely do that. , okay. I guess I was
167:29 at it like the rift basin that had that was failed. Um I
167:35 that to me was normal that it have a present day time curve or
167:40 curve didn't go all the way to time. Um But so the idea
167:48 , is um sketch curve, it matter ritual based on well data.
167:58 ? We started out with, well , we made a straight column and
168:02 from that we derived the subsidence We did that on the board one
168:06 . Um and I can do it this this afternoon, once. So
168:12 when you drill a well, the at the surface, they are not
168:16 day rocks, maybe you're walking on surface that is 100 million years
168:21 So in that particular case, which often do, if you add that
168:26 here, if this is just really the the youngest rocks that are in
168:31 Well, right, you may end there so you don't have to extend
168:36 to present day. But if you have data, you know, for
168:40 , the Foreign invasion, you do , you know, a sedimentary layer
168:44 is the positive maybe in the Pleistocene Holocene, you are allowed to sketch
168:49 like that. So often when there's data, people don't draw the line
168:55 . Okay, that's that's also the . That makes sense. Right.
169:02 talk about for our bases. So to give it away is for our
169:06 , that's the only type of sedimentary that hasn't, that's very specific shape
169:11 subsidence curve pull apart basins do rift marches to rifts to feel drifts to
169:17 basins for land basis, everything except for our basins. And I'll explain
169:23 next why? So let me quickly to that power point. I just
169:33 to find it here for faces. it's a pleasant, very short power
169:45 and that is actually because these basins a mess. So um there's stuff
169:51 can say about it, but not much. So we can go through
169:56 quickly. Let's see if I can it. Thank you. Okay,
170:11 this sideshow this power point is called our basis. So far basins
170:16 are these bases that form between the arc and the accretion eri wedge.
170:24 in between here we create a little of accommodation space. This accommodation space
170:30 be the result of loading with that . Right, An ark is a
170:34 of volcanoes. So this is a big mask that you add to the
170:38 sphere. So there can be a bit of fletcher in them that can
170:43 loading from the accretion very rich. this is also extra loads added to
170:47 plate. The third components to the arc basin subsidence is um you
170:57 the deformation of this entire region. that region is the forming and
171:02 you know, the curse here is forming. So that adds sort there's
171:07 components and I think Meghan and you it may be unintentionally, but you
171:12 say it earlier today and that is subduction zone. So this year is
171:17 oceanic little sphere and then oceanic little subject. It often doesn't doesn't do
171:24 as nicely as sketched here. So abducting oceanic atmosphere, this may change
171:30 little bit over time, maybe later time. This sub ducting slab is
171:36 like this or maybe it is less and does more like this. So
171:42 time such as sub ducting slab, know, it doesn't always stay under
171:46 same angle, right? This changes little bit, it goes up and
171:49 , may roll back and forth So that's all will also result in
171:57 uplift or subsidence of this region. in other words, there are many
172:03 and forces at play that form this our base in the last one is
172:09 even if nothing else was going if you have an uplift of the
172:13 Neri reg here, which forms, know, a slow shallow, how
172:17 you say it's a low mountain about here in the back you have a
172:23 arc or dying out volcanic arc, literally form a basin in between.
172:28 , So that will be the catchment for the settlements. So, because
172:32 are so many things at play in a fore arc basin, they don't
172:38 typical subsidence curves. So you can't , oh a fore arc basin has
172:43 curve subsidence history like this or subsidence like that. They're all different and
172:48 are also different from place to place the for our basin. Okay,
172:54 all basins, we can we know we look at the curve, what
173:00 we're looking at except for the four basin. So dynamite. All
173:06 I'm gonna show you now a few of close ups for our basis to
173:12 you a little bit more of an of what they look like.
173:15 what you see here in this figure going oceanic crust and oceanic mental
173:21 So this here is the down going , oceanic atmosphere and this is the
173:27 zone area here is schematically shown that creature Neri wedge that scraped off oceanic
173:36 marine sediments that are now piled up top of that area. And sometimes
173:41 call in the literature, you can that people call this instead of an
173:46 reg. They may call this an eri prison. Just to let you
173:50 that this is another term that you often now switch the rights you can
173:57 here, it says arc massif that is that volcanic arc that you
174:03 talking about. Sometimes when it becomes large arc, many volcanoes, people
174:08 it an arc massif. So, should imagine here basically volcanoes or dead
174:15 , they would be present there. if you see in between the ark
174:21 here called the ark massif and a very prison, which is a creature
174:25 rich. You see that fore Arc has formed. But for patients
174:31 you know, when there was quite subsidence and you have a lot of
174:36 be for multiple thick for earth basin basically means thick layer of sediments.
174:43 these four are bases that can be thick. So real for are based
174:48 real based on real size. Sometimes some cases the package of sediments that
174:57 on this oceanic plates when it was subjected subjected was very thin. So
175:03 in that case you can't scrape off sediments from the down going plate.
175:09 that settlement package was very thin, can imagine that you will not form
175:14 thick cream missionary reg for a christian prison. And as a result of
175:20 , you can't really form for our because there's nothing to hold those
175:25 So in other words, if we have this precautionary prison well developed,
175:30 not gonna have a well developed for basin for our basin. Sorry.
175:35 in that particular case, you may a skinny for our basin that probably
175:42 not gonna hold be good enough for systems. Yeah, so for our
175:48 can be thick with lots of sediments you have a sick creature, very
175:53 and an ark for ark basins can thin, almost non existing. If
175:58 don't have an accretion erI prison, really haven't scraped off much sediments to
176:02 with and then you don't create create accommodation space. So then it's not
176:07 result in anything questions. So the of the ocean, oceanic crust has
176:17 lot to do with you. A erI prison. The seconds of the
176:21 power that you find on the ocean is directly related to the preaching and
176:26 , correct? Okay, if you have any sediments to scrape off,
176:32 not going to form the prison, ? If you have sometimes when you
176:39 at an oceanic plate, it has four km of sediments on it before
176:43 comes to the trench. If those all going to be scraped off,
176:47 can imagine that you end up with very thick wedge of sediments and that
176:52 a perfect basin on the back side it. Yeah, so, we
176:59 this a four Earth basin questions so . No, So, these four
177:07 . Again, they don't have a nice subsidence curve, It changes from
177:12 to place and that is because there's many different forces or components involved with
177:18 subsidence. And then there's the last and that is that you can imagine
177:22 you start to push this and this wretch starts to build out your also
177:27 deform those settlements very strongly. So, it's really a mess.
177:32 subsidence curve will be a mess. won't give you anything good.
177:38 so, you both remember the difference the four art base in a foreign
177:43 space and Yes, ma'am. All , okay, now we're gonna look
177:51 this figure. This is the picture shows a similar situation, but from
177:56 little bit larger scale and I flipped so towards the right, we can
178:02 see down growing oceanic little sphere, a crystal layer very nicely indicated
178:07 and little sphere below on top of ocean accursed, we find a layer
178:13 sediments that's indicated here with agreeing the stripes. Most of those sediments are
178:21 off at the trench and they form discretionary wedge or a christian erI
178:27 Some of these sediments, they go with that oceanic plate, they have
178:32 been scraped off, but they you know, they hold a lot
178:35 sediments, right? These are sediments the sea for the sediments and the
178:40 hold water and that water is at point in time not gonna stay in
178:44 sediments, it's gonna be removed it's gonna move up, it's gonna
178:49 the rocks resulting in this volcanic So, so far, we're familiar
178:56 the picture. Now here, this build up this volcanic arc here,
179:02 ? You produce a lot of sediments then you have your fore arc basin
179:05 this volcanic arc and that's a christian prison. Any questions so far about
179:13 ? This is the story that we've so far. Now, I'm gonna
179:18 something else in the picture, that's following. So this seduction zone,
179:26 is abducting oceanic little sphere. What often see that it does is if
179:32 look at it 10 million years this small hole, which is the
179:37 mental boundary, I'm gonna use it a marker 10 million years later.
179:43 may be here and this may be base of the little sphere and basically
179:48 entire subduction system has moved towards the , we call that roll back,
179:56 has rolled back. So that means this all is gonna move with
180:02 right? There's not gonna be your you're gonna move it with it.
180:08 you know what that means? If start to move all this in this
180:12 because there's not gonna be a whole , you need to have an extension
180:16 a rift zone somewhere to make up that space and that extension zone is
180:23 be far inland here. And we this the back arc. So we
180:30 here the subduction zone, here's our very ranch, here's a fore arc
180:34 , here's our volcanic arc here in back towards the back on the backside
180:40 that volcanic arc. You often see there is some extension and we call
180:45 a backer basin. The reason that extension occurs is because this slap rolls
180:51 and then there's not a hole in earth, but it's just going to
180:54 until it feels of that space and does that in the back arc
180:59 So this here is a back arc . So we have subduction zone,
181:05 have here a trench, we have a creature Neri wedge or preaching in
181:09 prison for our basin are volcanic And then here we have a back
181:16 basin, a back arc basin. not talked about it previously because it
181:21 simply a rift zone, but it's rift zone in a special location.
181:28 that is why we call it a basin. You can recognize here the
181:32 faulting, you see that those are faults and then here sometimes these back
181:39 basins, they stretch so much that start to form new oceanic crust.
181:44 that is what you see indicated Questions about this. Excellent.
182:00 let's summarize the four basins. So four basins are these basins here,
182:06 go over them. These are often D positional basins on the trench sides
182:12 the equation very rich. So there the christian, very rich and the
182:17 they met. Some of them are to 700 kilometers long. So the
182:21 that we looked right, that was great valley in California, that's a
182:25 long one. They over lipe they set a creature very prison.
182:32 are christian, merry christmas, maybe the land surface, for example,
182:36 California, right? Or refined to coastal ranges, but they may also
182:41 covered under water and other places, completely underwater. We find several kilometers
182:47 sediments in these for our bases. these are um you know, these
182:52 real basins that we're talking about. some are deeper, some are
182:57 but they're real basins we find often icts in them and we find often
183:04 conglomerates in them. If the if if the settlements are coming from the
183:08 volcanic arc, that mountain range, might find conglomerates and you often have
183:14 a lot of service sites in So gravity flows underwater, gravity
183:20 Volcanism in these basins is rare because happens in the volcanic art, not
183:25 much in that fore arc basin Let's see, I'm gonna go to
183:32 one. So this is a figure shows subsides curves for for art basins
183:39 you can see different examples towards the in the center and towards the right
183:44 vertical axis. Here's depth, Exorcist time, we've seen the subsiding
183:49 many times before. And this is a collection of about 10 or so
183:53 our basis on earth. So what you see? You see that are
183:58 different. Some of them subside for long time. Some of them not
184:04 much, but subside gradually. Some them subsides very rapidly. Some of
184:10 have this weird subsidence history with pauses it. In other words, they're
184:15 different. So These these subsidence curves these four art basins. Yeah,
184:39 broke up for a second terry said cut off after um you said something
184:49 these four or subsidence curves and Yeah, yeah, sorry about
184:54 So I saw it on my screen there was nothing I could do.
184:57 um what I wanted to say is the subsidence curves of all these for
185:03 bases are all different. You see some are slow, some are
185:08 some are irregular, so much steps them. Um Some are fast and
185:13 , some are slow and fast. all different and that is because these
185:17 are basins have such a complex So we can't say, oh,
185:21 all form like this or they all like that. They have these different
185:25 in them. Does that make Yes, ma'am. Alright, questions
185:33 this. Okay, so here they . Let's see, oh, I
185:40 have to go through this because we run through this. So for our
185:45 here, Great Valley in California's sierra , the old volcanic art. The
185:51 ranges is the old accretion eri Questions about four are Basins. If
186:05 , then I'm gonna. Um I sharing already. Right. Yeah,
186:12 , good. So um what we do now is we can have a
186:17 till one PM and then this afternoon gonna go over pull apart basis,
186:24 gonna do that right after lunch. then I'm going to talk about modern
186:29 in basin analysis, in in in petroleum industry. So they are related
186:34 heat, geothermal energy, machine learning you may have heard of artificial
186:41 big data. And then at the of the afternoon we're going to summarize
186:46 the basins again and you know, to prepare you well for your
186:52 Sounds good. Alright. So I see you both in about an
186:59 Okay. Thank you. Great. you later.
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