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GEOL6358 Terrigenous Depositional System - Day4 10-02-2021-Part1
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00:05 Okay. Yeah. Right. Okay. Yeah. Yeah.
00:22 Right. Oh. Oh yellow, calling up, could you sleep?
00:33 this just a little bit. That's . Uh huh. Yeah, that'll
00:41 great. Thank you. True, sorry. Yeah. Okay. Uh
00:56 . All right. We now have car. Okay. I left last
01:03 suggesting this is a good kind of for the transition from open overfilled to
01:15 filled folks. And uh the next also summarizes the properties. Right.
01:27 in terms of the continual video, matter structures, mythologies, material,
01:36 a lot of information here. It's pretty good, but some of it's
01:40 simple to kind of recall and uh , plant propagation going into the
01:52 uh productive chemical. Uh So look this uh I'm not going to ask
02:04 a lot of details on this, the general picture should be fairly evident
02:09 now. So here's just a picture one of the uh lakes,
02:17 some one of the local custom deposits reservoirs for china. A lot of
02:23 uh really seminal work now is being in china. Uh you'll notice this
02:32 this particular case, it goes from overfilled lake system and what they're looking
02:43 , their defining it as a change accommodation frame a little bit changing uh
02:50 . Uh Certainly when we look at scale, uh changes in accommodation
02:57 tectonic activities, major factor as can . Climate change is a major
03:03 Okay, Now, I think what asked about the east african rift
03:11 I'm going to use that is one my modern case studies. Uh,
03:15 see this, this system coming Uh, one of the things to
03:22 out is that when we look at in detail, even though it is
03:28 extension all system, it consists of series of problems. So we're gonna
03:35 at problems uh, to get a of what uh, they're uh,
03:42 of pattern is. So we've got master fault here and then a master
03:48 master fault there. Wish a hinge on that side. So, beginning
03:55 see a consistent pattern here with these broadly and uh, basic, both
04:04 intentional and even extension. Okay. , now, one of the things
04:09 note here is that these are very lakes, uh, 1.5 kilometers deep
04:18 six kilometers upset. So this is major long live system going back to
04:26 seat. Also notice this here. , we tend to have the false
04:36 being accommodated by this accommodation. okay, so we'll see where that
04:45 in. Sitting here here, we him Arjun left lower case.
04:54 and then the market here is the . Masterful. Masterful. This is
05:01 zone transition by which the strain is . Uh, this is a reasonable
05:12 , idea of what the types of environment that they are setting like
05:18 Uh, where we look at the margin little kid fan belt, take
05:25 dog, we look over here, looking at larger deltas in this particular
05:31 . Probably stream flow deltas could keep . Okay, so we got larger
05:38 head smart side reflecting the large area uh drink there very minimal green Nigeria
05:50 uh down below and got a lot past le you got. So I
05:59 a perfect clothes that are coming down some blue custard fans. So all
06:05 these species, when you look at more get to them. Uh so
06:11 , just kind of close up on a cemetery that reflected both in the
06:18 style and in the type of, course uh that session. Yeah.
06:31 when we talk about mhm He said really is deep environment and it tends
06:40 have a lot of fluctuation in water . Uh these legs can vary
06:48 So as a result, we have lot of features that really look a
06:53 like kind of largest. Uh we ice and delta as a ghost and
06:59 we get inside down sub custom we get subbed custom, say Malcolm
07:09 his family. So these are features we associate more typically with the marine
07:17 , but that we actually get them as well. Uh so this is
07:21 like back to that idea of cemetery the rift and then realizing that and
07:29 got wait stand coming in, the more regular belts is here. That
07:41 up what it was really proposed as model for a rift basin in
07:50 But it turns out pretty much And that is that the active margin
07:55 evangelicals. Uh, well fan belt degree and larger deltas on mason margin
08:07 a longitudinal river filling to a lake filling. Okay, so we've seen
08:15 . We saw it here for uh, in Norway immediately. All
08:21 , grain flow down to the green delta. Uh, the late coming
08:28 uh, actually delta coming into filling legs. We stay here like uh
08:41 delta's on the other side filling in to time. And of course we
08:47 here where we've got there were killing that goes like as we do
09:02 So one of the study questions might , oh, describe the basis track
09:12 a rift basin. Uh, both plan view and Matthew Now the map
09:20 will come up just a month again the cross section. Uh, so
09:29 is the simplest view of a building them. And so we had
09:39 real sadness and speaker sir. And uh, we have deepening remember how
09:47 talked about as subsides defense. We from rivers, lakes, uh,
09:54 eventually filled with deltas, rivers and notice right here. Uh, basically
10:02 point where the faulting is, so began to have a spill two.
10:11 you know, uh, sediments and is sometimes called a long, so
10:18 born. So this is a good one except what's missing in this
10:30 This cross section and the fans. . So clearly I wouldn't want this
10:36 be your ranch, but you can with and then modifying as we talked
10:44 . I'm going to take a break just a second. I seem to
10:47 getting an echo. Um mhm. , I think. Okay.
10:57 So here we have rubio with little , large deflects, shallow lakes,
11:05 . Why can't you bring out Okay, now it's time more
11:14 information on the Grift based series in , the eastern part of us is
11:26 , uh, basically east africa and goes because this was essentially the rifting
11:35 north, the north atlantic. So bases here are pretty much the
11:43 Okay, so uh, this type system uh, is coincident are being
11:51 by, is that right greeted true uh, is seen all along both
12:00 the atlantic market in north atlantic and atlantic margin. A lot of the
12:08 salt basis that we see in brazil basically the script nations. So imagine
12:17 action was bordered breath, but it split off season process from happening here
12:25 go from Mexico. That's what we here except we don't have the
12:30 It seems too far more and we have the evaporates down in south
12:35 What was the agent at Triassic well up here is Triassic when you
12:42 down to the south atlantic. It's maybe vicious opening up south atlantic more
12:57 . Yeah. Now, one of things that we see particularly well.
13:05 huh Especially in the base should do are very, very laminated us like
13:14 loyal share its organic rich UK. when we look at these individual
13:22 uh, we can actually subsidize two which tend to be annually stratified.
13:33 the racial get right right variation for nomination. Uh, any variations,
13:46 myself, uh, these are not very finally laminated, but they allow
13:55 to actually begin to document how long lake was being filled. Uh,
14:01 then there's some others as well. , I refer you to this diagram
14:07 to this articles, details point is looking at various lamination, both,
14:16 , with yeah, by biological material courage in this material. Uh,
14:24 allow us to look at seasonal Now there's a irregular lamination.
14:34 these are just other events. So going to focus right now. The
14:39 part the uh, yeah. And what you can do if you had
14:51 lot of patients. This, basically count you number the eliminations and
15:03 apply a helicopter. It turns out , uh, you get experience of
15:10 . Yeah, These cycles or basically gate fight cycles. So, we're
15:21 at variations in the relative power So we can determine, oh,
15:31 . Spring tides, 22 years. Union, last immigration period.
15:47 there's a lot of information that can seen on the climatically driven variation.
15:53 that's what we get down here as look at larger, larger cycles begin
15:59 see things Like by eight Oscillations evening a film. So we're looking at
16:14 variations that compose on March, large . Okay, now going back to
16:23 diagram here, we talked about dealt with great delicacy on delta's.
16:30 , but I want to focus on now are like Custer's deltas.
16:35 and yeah, really the myth is the custom deltas are characterized whole flow
16:46 Gilbert delta, Gilbert type delta is too steep for set. Yeah.
16:53 , yeah. The reason why people that, first of all, hi
16:59 techno flows. That is to say , uh, water coming in is
17:04 saving water in receiving. Basic is the same. That is a freshwater
17:11 freshman. That's mainly with open It's clearly not the case. We
17:17 closed. Uh, now based on flu studies that showed that it soon
17:24 the river is the standing body of to spread out like this very
17:31 So the idea is that you get rapid steep Gilbert type delta and in
17:39 the first deltas that were looked at terms of lakes were around salt lake
17:44 like where they did a very steep . So it seems reasonable when this
17:49 kind of a typical example. you may not think this is very
17:54 and actually it is for a Uh, Mississippi delta has a slope
18:00 less than one degree. So we now statements, is that 20
18:11 uh, I think in some uh, here's an example of a
18:18 horse, rain gilbert like built, . Uh, this is just a
18:24 more details, killing, uh, uh, system, uh,
18:38 Okay, Say it again. What your back, you know?
18:49 yeah, don't look too close Uh, so not a surprise with
18:57 deltas. Uh, speak for, we get a lottery working a lot
19:02 mass wasting, a lot of slumping material comes down here. So this
19:07 all well documented, get classic top for set bottom set structure.
19:15 Uh, so it's gonna look and again, a lot of reworking
19:24 lot of re deposition coming off a deltas. Here's, here's the
19:31 The steep four sets are not the of homer signal flow, there are
19:36 result of deep water. And so turns out that a lot of
19:42 the banks, uh, the likes Gilbert type delta is performed were fairly
19:49 rapid rise. And so they were , steep deltas, but we can
19:55 get steep marine deltas. Gilbert type that are any fiore's, for example
20:02 off glacial out wash. So, , when we look at uh,
20:08 delta's more detail, we find out the first of the young girls and
20:14 , lace uh, name. they shall walk up to, It
20:19 depends on the the flavor of uh . Now this particular page two,
20:31 begin to and a higher water into kill work over the show water.
20:44 yeah, I'm here to say show water dealt grading into good films.
20:53 , So yes, you can get type deltas in place, but it's
21:00 state to assume that is characteristic of custom health. Uh it's a characteristic
21:07 deposition to keep one. Now there two other situations that we have with
21:16 to the yeah, inflow of water sediment into standing body water.
21:24 this this whole from marine as well like we could have a hypertext
21:31 So this would be a case for river has so much sediment in it
21:37 it is actually more dense than receiving . So that would be most likely
21:44 happen with fresh water and a lot set coming in. So maybe and
21:53 Family Brother radio. Yeah, flash or something. In that case the
22:00 is actually sets up a density This is what we call alternatively what
22:11 typical in most marine deltas, but in salty saline delta. Is that
22:20 the water is not dancing saltwater even the combination etcetera. So it overruns
22:29 you get population deposition extension. So get the more typical deposition now in
22:38 , we can go from this to with climate chief we in fact saw
22:43 if you recall back all of yesterday we look at the hyper saline lake
22:51 brackish where uh the changing climate that getting in some resorts, uh during
23:03 low stand it was brackish water. , Or And so you hadn't seven
23:13 high stand with more rain. There a brackish former. We actually had
23:22 these were the seals. I'm These were the reservoirs. These were
23:28 this this particular example late was actually okay. So there is a second
23:36 of custom delta and on Gilbert got and this can alternate from different climatic
23:46 , but also between floods. Takes Little Slice so we can get periods
23:53 high suspended load coming in That ends developing one victim. Or we could
24:03 smaller floods where it's not as So, these hyper pink nights are
24:10 density terms. Uh arguably they're not ized because as ill defined them.
24:20 this is typically defined turbid ICT uh usually set up by a kind of
24:29 flush of sediment. These hyper pick are longer lived because you can have
24:37 a flood that can go on for or weeks. So you're constantly feeding
24:43 hypertext night. Whereas with a turban is usually a sudden event.
24:49 we'll talk more about this. Just just a few moments. I want
24:54 look at some of the chinese basis there's a said earlier that for most
25:00 the okay recent work being done in variety of basis but high bases.
25:11 , these are bases all over china they are sourced by and in some
25:18 the reservoirs are like customer deposits. . Uh, this is the URL
25:24 basin. Uh, if you look some cross sections, you basically see
25:28 a bunch of half problems. you look at the high basin same
25:34 , bunch of half roberts. so the first thing is fair enough
25:37 say that these half Robin model is to at least keep in mind.
25:44 . And so this is what we're at. Begin notice secrets. Downgrade
25:49 stand. I stand so beginning to at basin scale evolution in replying
26:00 strategic graffiti to these lancastrian department. , we also see fan deltas over
26:09 . Uh middle sub custom fans. on the other side we're getting great
26:16 . So again, this model is least in the simplest way. Uh
26:21 out, there's a lot of details might expect going on here. So
26:26 gonna look at one study chang song all. Uh it's a nice study
26:31 the puts all the deposition of grants . Uh, Alluvial fan and
26:39 Uh, basically alluvial fans are water . Can you break out just signing
26:46 something like shell and big late. . Uh, and I just had
26:55 report risks. Let's so look out better said. Yeah, the five
27:02 materials are not risk. Your periodic of picnics can be okay, alluvial
27:10 . This is, we talked about , they've got the great flow.
27:14 is possible fan, she floods extreme fan, but it's the fan deltas
27:23 are more interest because as you recall fan deltas, we're getting a rework
27:30 the uh, this proportion of delta ways. So we're getting a pro
27:38 delta front that actually has some reservoir . Uh, this is from a
27:43 basin, but again, it shows , appropriate clothes. Uh, I'm
27:54 , I'm a little questioning whether or a fan delta, but in any
28:01 it shows the pattern, uh, coming into the system. Uh,
28:09 is also good place to point out fact that you've got to be careful
28:18 trying to correlate these delta process with crunchy with little integrity he did.
28:26 would be pretty easy to basically uh these straight across. But what you
28:34 be missing the fact that there are lines. Steelers that are basically meaning
28:42 these Samsung are not necessarily connected. that if you look at this
28:52 well, this is actually in but this is the connection you would
28:57 made if you just looked at little . This is the connection that actually
29:06 . Look at, oh deposition. a possibility You got a 43% increase
29:20 the risk for once you started realize was, and we'll see some
29:31 especially what was never clear to is the scale horizontally. I
29:38 on what scale do you start to ? We just can't carry these across
29:41 actually need to be dipping planet. , I tried to wait 500
29:50 Say it again, 500 years. yeah, this is about 500
29:57 So this is half a block. really, Yeah, and it's still
30:02 good. Okay, that's where you to really look at how these reservoirs
30:10 connected. True, we'll talk Okay, so here's a fan belt
30:18 uh possible to distal. Uh here have bad deltas on one side graded
30:31 great deltas on. So again, in front in this particular case,
30:39 all filled in by this stage. fan belt from here, uh extremely
30:50 . And so there's a lot of . This is 2018 about how you
30:56 to look at these photography in great . Really began to figure out how
31:03 do one of these basis. Uh Delta said are going to be better
31:13 have fair sequences. 20-30 m. , uh, it all depends of
31:20 on whether or not we're dealing with overfilled delta or not. Okay,
31:25 so here we got things uh, to be handling the health, don't
31:32 ? Possible margins, no coming up the lake. You noticed with a
31:43 . So this particular sequence. Uh are serious allegations, but getting bored
31:54 . Oh, anyway, the Yeah. And this is again an
32:05 , time slide. We tend to visualize what these deltas on the fracture
32:16 looked like. Now I mentioned earlier were high stands and most stands and
32:23 , depending on where you are, can engage in the I stand,
32:28 got the largest hedge you may actually built. Remember I talked earlier about
32:36 wave feature the than barrier islands or or wave dominated deltas could occur during
32:44 stands. During low stands. if there's going to be a
32:50 uh, is more likely to be being dominated because you just don't have
32:55 way. Okay, okay. Now you look at the effect of definition
33:03 channel, uh, looking at decrease we go from the channel offshore.
33:16 again, strong correlation within a definition the term inability. Thank you.
33:23 mean size valley film. This is suburb uh, industrial valley.
33:30 we've got a lot of one coarse sandstone. Uh, those tend
33:36 be submarine grafting clips or some Right? And when we look at
33:44 , uh, uh huh I said they can be wrong because partner coming
33:55 hi golly how the A. Diverse as opposed to the delta.
34:11 how much wider delta is. then the silver custom saying this would
34:18 an example uh sediment gravity social. in some cases up 60 m thick
34:31 . And this is again, I di agree these fans wait floor
34:39 that are gradually. Yeah, we see here is this this is
34:45 lot like a submarine champ. The processes are largely the same.
34:54 . And again, just in terms permeability, uh, you're looking at
34:58 average of about 200 million Darcy. up to to do it 20
35:05 So what figures what? So these really very good residence. Not to
35:17 the fact that there are sourced by fine grain settlements. So we get
35:25 density here. They call them turbid . There are degree flow deposits.
35:31 are seven vette interpret eyes. And , as it turns out, a
35:34 of these are actually pick nights. , but uh this is the these
35:42 the reservoir face. She's for most the lancastrian deposits. Uh, this
35:48 a fascist map. Here's a delta down to uh look down into
35:55 curious what we've got. SaN moving be blue lake deposits. Now,
36:08 Sebelius, probably four. Sure, density. You're dying, I think
36:19 . Sammy money. This could come out of the lecturer. Uh,
36:27 is some question about the difference between long lift to the current. Pick
36:33 flow. I'm not gonna get into particularly, but this is the spectrum
36:39 de positional settings that you get in subway customer deposits. Uh, for
36:47 trigger. Uh, we're coming down at, you see these are,
36:59 , wow, I'm not going to into the details, but you can
37:07 a variety of patients changes within the course defined, but also other types
37:15 changes. Uh, so what we're at is uh mainly high professional flows
37:24 flood generated. Okay, so, brown plans further are into the basement
37:34 . Like these are Elvis here, and Rick and Elka. Uh,
37:42 know what they are with the likes a unlike. Yes, yes,
37:48 is the equivalent of like shelf, is a public slope and on so
37:56 size channel summary something Professor business. , we also get slump generated.
38:12 , these are going to be more during bos stan, you've got the
38:19 water. Okay, wow. So is going to a kind of the
38:27 of the platform uh that we talked when we saw the steep delta.
38:34 Gilbert, this is a more typical . And particularly if you have a
38:41 sand, low stance shelf, like do say in. Uh, so
38:48 can't make up, this is just picture of what these two look
38:52 I'm not gonna get into details on at this point. Uh we're gonna
38:59 of defer to the lectures towards the of the semester, but one of
39:04 things I do want to mention is , you do have a lot variation
39:11 sentiment structures and you feel proximal to disproportion uh, ready, uh,
39:21 infrastructures. Again, not unlike what would have in uni directional flow,
39:28 all of these potential, albeit very for reservoir developed. Now, let
39:36 point out one thing about hyper pigments this would hold for something custom or
39:44 and that is that unlike the surge where usually a failure results in
39:55 the lapse of sediment and then it's its goes down straight. These things
40:00 basically Just loading hold for seven uh have some long period of time.
40:10 of these folks in last weeks or . Yeah. So what we see
40:16 where the energy is increasing the Uh we eventually get our erosion,
40:26 suspicion of sand and then re suspension your life. We've got a long
40:35 of time where there is erosion beginning position. What time, what that
40:43 is you don't have the classic knowledge which is basically deceleration, you've got
40:51 waxing and waning, acceleration, acceleration, deceleration and so what that
40:58 shown is in here where you have sobriety claim that around ripple basically you
41:12 subdivide it to get a lot of finish this within the same event.
41:21 these picker and a turban. I and they will have more variability at
41:28 in terms of waxing and waning. you can see that even here where
41:34 begin to see of course not Oh, whole series. Um waxing
41:44 waning events. You have a Yeah. With him, the fence
41:51 escaped. Okay, uh, Again, standing debris flows coming off
42:00 , slow uh, they actually are have Pirmin abilities up to $4
42:07 Sees the thing about a debris flow a slump. Is that all depends
42:11 what you start. If you are something that's already relatively well sorted,
42:17 it's going to be a massive well of the bottle. So it's,
42:22 the target if you're slumping something, whole bunch of mud in it.
42:26 not. Yeah. Now we can to the North Falkland. This is
42:33 bit of stress. But again, can see you see yourself western martin
42:40 eastern martin syn rift closed ribs. is basically a longhorn model. And
42:47 point to make here is that we have these high standards shuffle uh
42:57 inside stands to a series of side feeding uh, lakes. And so
43:06 you look at those fans detail, , you can begin to see these
43:12 of low bait globes and these are reservoirs uh, in Norfolk.
43:19 uh North wall base, you can , you can break them up individual
43:26 . And those lobes are characterized by types of rock, uh, including
43:33 reservoir and non. So this is the same kind of process that
43:40 we deal with when we're looking at uh close. Uh uh Now,
43:48 we get into the shallow, I the shallow, these fine grained
43:53 Uh they are going to be mud stones and activated. Find great
44:04 way thinks deeper deposits. This is you can get laminated oil shale,
44:15 organic content. Oh yeah. And there will be some intervals where you've
44:22 some some Republican fan city. So is the interval between fans or adjacent
44:29 fans. Okay. Um I'm gonna this and just give you an example
44:39 how one basis that involved in Uh You start off early on sediment
44:47 greater than accommodation states. You've got it's move your filled gradually deeper accommodations
45:00 shallow because you've got fan belt Brain . And then it begins to get
45:09 deeper plane. Yeah, accommodation is . We still have great deal begin
45:21 get deeper water custard deposit, incised , and sometimes. Okay. And
45:29 it showers. So we get something looks kind of like this. This
45:36 actually a great process. You keep fine adding to it. What happens
45:44 ? This one you then great up delta. New deal uh spread out
45:55 real God. It's not always gonna this secret because it all depends on
46:02 relative rate of sediment supply to Okay. Uh But here, for
46:10 , if a mobile over house So each sequence may be a little
46:19 . But having said that, what when you look at the subsided
46:28 Well, that's my sad, you . Uh And you look at different
46:35 . It tends to be worth a lakes are that's not a surprise,
46:39 it's also where you get the source . Uh S our social large grater
46:51 . So what happened about 40 much . So he had that satisfactory
47:05 maximum sort of one so long as , afraid to look over some critical
47:13 . No, I mean uh that's you begin to get your source
47:20 Well, that will then become uh feed stop for your reservoir books.
47:28 . Source rocks and vibrate up, in the subway. Custom fans with
47:37 picnics etcetera. Okay, now there's thing that several things to keep in
47:45 , I would like to unconventional resource like lakes. Uh huh. For
47:53 most part they have four reservoirs. not all of the legs are going
47:59 be uh targets. On the other , the legs are geographically limited,
48:08 they can be great thickness. So great thickness actually is greater than in
48:16 cases every encounter. That means there's more limited four area from the custard
48:24 . So we can look at Uh Here it is. Yeah,
48:33 why it is like here look at great salt lake. Oh, this
48:42 a deep part of that life. is the participants. Uh This is
48:50 core where you're likely to be generating . The great thickness lack of carrier
49:03 can result in more lending ability to and mobilizing. Okay, they may
49:11 favorite post Triassic in part because had after the Triassic began to get biogenic
49:20 . You may recall when I talked biogenic silica and its role in composition
49:30 mud rock. Mm uh we didn't those until the diatonic is not in
49:38 they add to the brittles. So you have a pre Triassic mud
49:46 it's not going to have much much . So it's not going to be
49:51 brittle. It's not gonna be as fractured. Uh And also there's some
49:56 with respect to the title what that get a type of uh huh So
50:06 just uh huh. Well I'll just with this. You have we had
50:16 stable in this particular case the younger uh this was permanent pre Triassic stable
50:23 water and toxic with high sailing stratified center concentrations regarded organics will preserve it
50:35 organic resource wants former too high Okay, so that's the story from
50:44 customer deposits. I'm going to stop . But the main thing to keep
50:51 that here you're not the main But one of the things is that
50:58 of the similarities between custom rocks and lots, particularly in the deeper water
51:09 are striking and will become more apparent we talk about deepwater settlements in the
51:17 . But so let's just stop stop recording
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