VideoPoints

• ••• • •• • ••••• • •
GEOL6358 Terrigenous Depositional System - Day7 03-10-2023-Part2
Help Tour
© Distribution of this video is restricted by its owner
Transcript ×
Auto highlight
Font-size
00:00 Um But since we're recording, you're , OK. Um I posted
00:08 a modified set of notes just a of hours ago on Hyper Pit
00:14 So you're gonna see a bunch of that you don't have in your
00:18 Uh Just note that those uh images all in the new nodes and you
00:25 go and, and look at that we go. OK. Uh But
00:29 do want to talk uh more about Picts in a marine setting, particularly
00:33 deep marine setting. Um And, what we know about them is that
00:41 they are basically flood triggered. Uh ba uh and, and we talked
00:48 them both in the context of lacustrine and marine deltas. Uh They are
00:55 fact more common in lacustrine deltas, we do get them in marine
01:01 And in particular, when we get the shelf edged deltas, we have
01:07 hyper pics providing sands into the deep . Uh This particular uh image simply
01:14 the difference between a uh kind of long lived sedimentary gravity flow. Uh
01:20 called here, a quasi steady low turbo current that's really gonna be your
01:26 or uh is it gonna be the uh generated or storm generated uh single
01:36 ? Ok. Now, in this here, what we're looking at is
01:42 single but simple event. Uh and , this is the flood discharge increasing
01:50 decreasing and the resulting deposit. If discharge doesn't exceed some critical discharge to
02:01 that turbidity current, you're not gonna a turbidity current. You're just gonna
02:06 the waning flow deposition from suspension. as that critical discharge is exceeded and
02:14 the discharge of the river mouth then you begin to see this secondary
02:27 increasing flow. And in fact, even going to have some erosion followed
02:36 deposition. So you see this little surface here, OK. Uh So
02:42 getting increasingly more complex uh patterns. , uh here, for example,
02:52 a, a, an example of single hyper pic that is extending farther
03:04 farther offshore or perhaps laterally and how changes with distance. So when it's
03:12 to the um with the maximum you've got a lot of scour fining
03:19 . Uh Here, you don't get mud fragments here. You're getting more
03:24 a increase, decrease, increase, and just barely have. And so
03:31 got a muds stone face, shes sandstone face, she and a pebbly
03:37 that pretty much is at the base present. And that's only going to
03:42 when we uh have very high flows . Ok. Now, more
03:51 we're looking at particularly with the river flood, a longer lived event that
03:57 highs and lows. Um So it's have a peak, a low,
04:02 peak and low. But in we're gonna have accelerating flow to the
04:07 where erosion and bypass, followed by and deposition. OK. And so
04:13 is uh a sequence of what's happening in terms of the deposition as we
04:24 the strongest flow and it might look like this. OK. So notice
04:30 this one here, I'm gonna focus this one. Uh We have a
04:35 of repetition. In other words, no single sequence like shown here,
04:41 rather, there's some repetition of uh to yellow, to orange, to
04:48 , to ripples, to yellow, ripples to mud. OK? And
04:52 of these has a fay name. I'm not too concerned with the
04:58 So you're gonna get them in a . But the point is that you
05:03 having various times during which different fishes deposited during that decelerating flow.
05:17 It turns out the reason I had add illustrations is I've completely forgotten about
05:25 particular paper that really is probably the best paper on Hyper, particularly in
05:31 marine setting. And it's published in really bizarre journal that I don't normally
05:36 uh lithic reserves or re uh uh . But essentially, you're looking at
05:45 , this coarsening and finding and coarsening finding event ok, similar to what's
05:51 on here. And we're looking at it varies distantly. And one of
05:57 things is that you've got a bed component and a suspended component, bed
06:03 drops out suspended is deposition and notice happening here. We're beginning to have
06:09 loft. The, the head of hyper pics is actually beginning to become
06:18 dense and is floating. And then other things, you have settling out
06:24 suspension. And one of the things settle out of suspension, a lot
06:28 organic materials including leaves. So this the way we end up seeing leaves
06:35 deep water setups by these hypericon night are coming from the near shore.
06:40 there's a face bs face, Well, that's basically bed load sand
06:50 . And so here's what it kind looks like. Um Here's massive
06:57 that's one of the most common species the hyper pic event. OK.
07:05 This is the downstream change there. what we were looking at here,
07:13 down current and it could extend for of kilometers. Yeah, here is
07:24 change. What this is doing. extending away from the channel. It
07:29 if you like the levies. So in the channel itself, we
07:35 bed load deposition. But as we away from the channel, just like
07:41 we move down current, we're going this massive sand, that's arguably the
07:50 important because that's gonna be your best . And then as it gets farther
07:55 , you're getting, uh, intubated , rippled sands, uh, and
08:00 eventually it's beginning to loft and then beginning to get the, uh,
08:07 stones of the loft faces. Ok. So here we've got this
08:15 flow and we've got three faces Faces, one faces to in phases
08:31 Fay three is climbing ripples. Faces is parallel lamination and faces, one
08:41 massive. Ok. So you go massive to parallel laminated to climbing
08:49 But notice that it kind of goes and forth. And so what we
08:56 here is something that might be S , S 2, S one
09:04 S two S 1. OK. all of that is one flow but
09:10 varying discharges and velocities and sediment concentrations a flood from the river's mouth.
09:18 we look down here, we're getting sim similar fluctuation but of a more
09:25 face. She here we're getting That would be three, two.
09:35 I can't read it. Uh But , this would be uh anyway,
09:44 it ripple. That would be 232 . OK. So you get these
09:52 , OK. By the time you down to the lofting face sheets where
09:57 getting basically muds and there you're getting and decrease velocities showing increasing and decreasing
10:09 and mud size. So it looks like this and a single event may
10:16 you multiple cycles because you're just looking the tail of these things.
10:23 So, in summary, if you're at that fluctuating uh hydro graph,
10:33 you like uh with the initial deposition when this is coming through and you're
10:40 , uh just uh a little bit sediment here but not much. It's
10:46 acceleration. Now, you're getting erosion bypass, notice you're getting erosion down
10:53 and then it's bypassing over here. you're getting sand to mud,
11:01 to mud as if it's a levee you're still eroding the channel and then
11:10 deceleration and deposition. And that's when get deposition in the channel of coarsening
11:18 or finding upward sequence from the gravels the middle to um massive beds and
11:26 currents. And then out here, , um you get the basically S3
11:38 floating. Ok. And these again gonna be alternating depending on these fluctuations
11:46 . Ok. So, characteristics. Well, actually I should have done
11:53 . Oh, I'm sorry, I'm gonna let you read these a
11:57 of big things, uh greater range thickness, uh terrestrial organic debris indicating
12:05 drive from a river inverse and normal within a single event. Now,
12:12 is different than a hybrid bed. I find hybrid bread still kind of
12:21 , but the main thing about a bed is that you're incorporating or losing
12:28 during a single event. So you're adding mud from the bottom or you're
12:34 mud from the top. And so changing the viscosity and the nature of
12:40 , the bed hyper pic nights fluctuate the event. And so you're not
12:50 at something added or subtracted in but rather you're looking at fluctuations in
12:57 source from that flood event. Um They're most common in lacustrine
13:05 but most rivers can produce them and of them are pretty common uh even
13:11 submarine cans. So these uh have recognized again, classic, you find
13:20 you look for and we're seeing these and more both in the rock record
13:25 instrumented in studies of modern deposits. . Those add contour rights and
13:34 a, A type of deposit that ignored until about 10 years ago,
13:41 or better said, ignored by the community because it was thought that these
13:46 just generate muds. Ok. Uh , in reality, there are any
13:52 sea sediment deposited and or substantially reworked bottom curs. Ok. So what
14:01 those bottom currents? They're thermo haing currents? They're driven by differences in
14:07 and salinity and they are global in , their extent. Ok. So
14:15 are, this path is just some the examples of these global uh thermo
14:22 bottom currents. Now, when these first described, they actually were described
14:29 silts and there's mud to silt, mud. Ok. Uh They modified
14:36 and we're gonna see the big changes occurring in here, but notice that
14:41 we look at this one, uh actually into fine sand now and we're
14:47 at a gradual increase and decrease in size. OK. And, and
14:53 a little bit here, the reason that is that these bottom currents are
15:00 continuous in velocity and location, bottom meander, they move back and forth
15:08 and when they move away, the decreases, when they move towards
15:14 it increases. And so what this package is looking at is one kind
15:21 back and forth motion of a bottom , ok? And this is an
15:27 of a core of one of those currents that's basically getting higher and higher
15:36 into the sand, lower and lower the mud. And so we actually
15:44 getting some pretty good sand deposits, fine grain sand, but they are
15:50 sorted. So what we end up are three types of contour rights,
15:57 bedded, thin uh thick bedded, , thin bedded, sandy and
16:04 thick bedded, sandy are what we're interested in for reservoirs. They're horizontally
16:10 , and ripple, laminated, fine , well, sort of sand
16:14 ok. Um The thin bit and I'll show a picture. So,
16:20 here's the thick bit at sandstone, ? And these can be in commonly
16:26 units of 2 to 8 m. mean, this is a thick sequence
16:30 basically, it's reporting that interval of when the contour current was closest and
16:39 high velocities. Ok. Uh They be units up to 30 m.
16:45 , we'll see a couple. The thin bedded uh are a little
16:53 grain and they are kind of in . They're getting more impacted by the
17:02 flow as well as the uh increasing velocities. And then as you get
17:09 away, you're just getting mud. ? And so, uh these are
17:14 much extensively bioturbated uh and are gonna our seals and potentially our sources.
17:22 . Um Sandy contour rides occur in , what we call terraces and at
17:29 exit of straits or gateways, the uh is basically a, a place
17:36 contour currents having been funneled, spread . OK. So we're uh we're
17:43 look at some of those and you read uh this a little later but
17:48 a look at this. Uh look thick That uh uh amalgamated Sandstone is
17:56 uh most of the porosity over OK? And then this would be
18:07 the, these are sandy. Uh then in here, uh we're looking
18:13 some finer grain deposits, OK? straits of Gibraltar uh have very saline
18:25 waters coming out of the Mediterranean. so as it outflows, it's called
18:29 Mediterranean outflow of waters. And those come out here, they form channels
18:40 in particular, They form areas where red is over 50% sand. The
18:48 red is over 75% sand. So are really very sandy deposits over hundreds
18:57 kilometers, allergy skin thing uh covers 4000 square kilometers, ok. High
19:10 to gross thickness of over 800 So this is a huge deposit as
19:17 modern analog or ancient contours. there's a lot of geometries by which
19:25 things uh accumulate. This is just of them. Uh Let's look at
19:30 here. This is um a You notice that the turbo has been
19:46 moving towards this channel may even be a little slumping here. Ok.
19:56 is completely welded on. So it's , there's the contour right right
20:03 but it, the velocity decreases. fact, if we look at it
20:09 , There's two water masses is one towards us and one moving away from
20:18 where the velocities are the greatest right here. We're actually getting sandy face
20:29 rating offshore into muddy faces and this just a mass transport complex. So
20:36 we were looking at a face track here to hear, would look something
20:42 this. Well, I'm, I'm gonna read this to you except to
20:48 here's a muddy fine sand, here's laminated sand, thick bedded, here
20:57 climbing ripples, uh bedded sand here wavy lenticular and muds. So what
21:08 actually have is a transition from sand mud. It looks a lot like
21:16 tradition we would get in a tidal . Ok. Wow. Here's some
21:24 of what they look like. And that uh massive channel bottom, there's
21:31 horizontally bedded, it, this doesn't mass but mass it would typically form
21:37 between these two, um, rippled . But, ok, so that's
21:50 face she track you get here. is missing in that? Is that
21:56 sound? Ok. So here's our bedded, thin bedded And Muddy as
22:08 that is mixtures of the two, mean of the different faces. Here's
22:16 contra channel. The contrast is moving like this. Yeah. And if
22:24 look at the faces going from the down, we get a sandy
22:35 right? Getting more muddy, more , getting thinner to muds.
22:43 This up here is stuff that's coming from the slope. OK? And
22:49 would be the channel, OK? that would be like this right
22:55 So we get such high velocities in contour I channels that we can actually
23:00 gravel transported. Uh This is just picture showing the same thing, the
23:06 , right channel with the Corus sandy contour rights, then they're getting finer
23:14 , interbedded with muds. It would this one it and again, this
23:22 just pictures showing what that lateral transition be right here. And pretty much
23:38 same, this is the Paleo Mediterranean water flow. So this is looking
23:47 some older deposits, but with the geometry of gateways skipped it.
23:56 what's stunning is that the more and we look at contour, right,
24:03 contour currents, The more we find sand and two bed forms in that
24:14 . So here we're looking at basically high velocity. This is in
24:23 the funnel gateways like within the straits Gibraltar and within the channels along the
24:31 , they would go down to the and finally the finer grain drifts.
24:36 look what's happening here. We get features like furrows, uh then gravel
24:48 and even barca dunes. Then as get into a little uh slower
24:57 we're going from large sand waves to sand waves to three dimensional ripples to
25:08 dimensional ripples, straight crested ripples, ? OK. That's our flow rece
25:14 seeing the same flow regime that we in unidirectional currents in a river in
25:21 counter, right? And eventually it into smooth sand deposited from suspension.
25:31 . Some of these Big Barca dunes five or 10 m high wavelengths of
25:40 of meters. OK. Now, was really uh prophetic in pushing the
25:54 early on that contour rights could be processes on turbo channel levies.
26:06 And what we see here is a of the levee deposit and a redeposition
26:15 material. OK. And so he that you might go from coarse grained
26:24 beds to lasure bedding and the bedding of the winnowing of the channel and
26:36 . And certainly we see that we that in the Delaware Basin. Uh
26:40 see lenticular bedding. Uh We see bedding, uh rhythmic betting. The
26:48 are this down in here, probably cycles. Um These are all in
26:57 water deposits right next to a great submarine channel. Ok. So when
27:06 , when you see this, you directional currents, you see mixed
27:12 hetero lithic betting, climbing ripples, . All of these are typical of
27:22 higher energy portions of contour rights, , levy deposits. Ok.
27:30 this more just for general information, is what a down current turbidity,
27:37 might look like. Ok. Um I won't get into the details of
27:41 , but this is what a right? Might look like. Reworking
27:48 channel and letting. Ok, so we've got is channel deposits here.
28:02 reservoir properties, reworked ripples and uh to coarse grain sand. Again,
28:15 reserve properties, medium defined grain that variable. And by the time
28:21 get down to here, uh we've too much mud. It's gonna be
28:28 or reservoir conceivably um tight, uh rather uh conceivably little fingers, but
28:38 it's gonna be tight. Ok. the idea of contour currents, reworking
28:50 or channels uh is getting increasing interest the last few years. Now,
28:57 this particular case, we've got a lobe and we see sand moving down
29:08 here. We've got the con or superimposed on the turbo and that's where
29:16 get these pro grading drifts that are the turbo channel to migrate. In
29:29 words, if this was the channel , I mean, then the deposition
29:39 causing it to migrate a flow if like OK, up flow in the
29:46 of the contour current. OK. these are just some examples and you
29:53 look at these at your leisure. But this would be what's happening as
29:57 going down the axis of the And this is as you're going down
30:03 margin of the channel. So here got that lateral change of the
30:16 Uh This is just showing what some these fine reigned uh contour. Rs
30:25 grain, uh medium grain sand look well sorted they are. Yeah.
30:34 we can have some very well And as I showed earlier, thick
30:40 and it not only is a way generating con uh more sandy contra rights
30:52 is leaving behind winnowed turbos. um moody called these the mystery of
31:02 missing turbos. And it really wasn't much that the turbo was missing,
31:08 the upper part of the turbo was . Now, we typically assume that
31:13 upper muddy part which is kind of low density turbidity current is simply continues
31:20 offshore, farther down street. And one process that happens. But if
31:27 high and low density turbo is coming the channel at the same time that
31:33 have a unidirectional contour, right. , this is actually stripping that finer
31:42 turbo and finer grain material in depositing down, dr enhancing the grain size
31:50 the porosity and permeability of that lower turbo. So here we've got a
31:58 sandy contour eye, ok? Great , muddy con and pretty good
32:08 OK? And it may even be source uh particularly given the or high
32:16 content that's coming down these things from and if it's deposited in an anoxic
32:23 , ok. So just show a of field examples. Uh We've got
32:30 near Mozambique, we've got a series fields that are giant fields. They're
32:37 of the most prolific exploration areas in world with over 80 trillion cubic feet
32:43 natural gas in place mainly in So there's the coral in the mamba
32:51 . OK? So here they are this is the depositional model. These
32:58 grain turbos are diverting the turbidity currents the channels and they are winnowing out
33:17 upper part of those dense flows, them in the lower part of this
33:29 drift. So the highest net to here are the main channel as well
33:41 some gravity flows that are coming in uh lobes and some of the
33:52 The closest areas of the drift. . Love net is uh um isolated
34:04 and the distal portions of the OK? And non reservoir shales.
34:10 . So we've got am giant gas whose main reservoirs are basically a
34:22 right? Winnows channel. Also some lobes down channel and the most
34:32 portion of the, the drift. other area that is massive contour fields
34:40 in Brazil offshore. These are sub salt, uh the Santos Basin,
34:48 compost basin in the Santos Basin. . Here's the southern Santos Basin.
34:55 what we're looking at is channels coming here and even lobes. And here
35:07 the erosional can do it of a , right? And their erosion
35:17 But take a look. Here's some can dunes. Uh Here's some sandy
35:25 . I out here, if we at those bar can dunes. Uh
35:32 are sand waves in here. Big can dunes and linear stripes. So
35:39 highest velocity is in the core of contour I channel and this is the
35:48 as the velocities are getting lower and . OK. And this is just
35:54 looking at some of the sizes of , some of those bar cans are
36:02 m high and a couple of kilometers . So it's not your like Zan's
36:08 can uh also get larger dune Um Where you've got all of this
36:18 sand, well sorted, sand skip um in the compost basin, here's
36:31 con rights again. And they are the distal lobes. OK.
36:40 instead of reworking the channel, they're the lobes and in the Santos Basin
36:49 , a lot of reworked deposition reworked channels and associated sandy contour
37:01 OK? OK. So let's call quits for now. Um I'm going
37:09 uh stop sharing. We're gonna take short break and then we're gonna start
37:16 part two and that is the Ok. Ok. Ok.
37:36 we recording. Ok, great. you. Ok. Um,
37:40 let's look at these systems in terms their storyline because surprisingly, well,
37:55 me, it was a surprise that you begin to look at deep water
38:00 throughout the world, they often in fact, most commonly have a
38:06 sequence, a recurring sequence of patterns it begins with slope failure. And
38:17 forms a canyon and that canyon eventually until it captures a sediment supply.
38:27 that sediment is bypasses the slope to deposited as a basement for a
38:37 And that as the sediment begins to , get more muddy, you tend
38:43 backfill the canyon with the channel levee and eventually mud grapes, hemi planted
38:54 . Now, there's a lot of in transit, but that's a storyline
39:01 we're gonna basically find provides a framework thinking about how these multiple sequences of
39:13 occur. So let's begin with getting uh getting sediment uh off the shelf
39:22 into the deeper water. And that course involves uh this complicated bemet that
39:31 see on the slope and slope failure particular. And there's a lot of
39:37 for this. Uh in some deposition can cause loading uh and that
39:45 result in sheer drink reduction and failure uh in other cases, uh you've
39:53 tectonic or sea level change that can in increased stress, uh and slope
40:01 a lot of these different ways. as you might expect, there's AAA
40:08 variation, not only in terms of and mechanisms for slow failure, but
40:13 the scale and geometry of those But let's just imagine in a,
40:20 a simple form, we've got the gradation of the shelf and failure.
40:28 Failure beginning here is a large slump slump begins to work his way across
40:38 stream. Until finally, it has least the potential for intercepting sediment and
40:48 deposition of the van. And you notice here there's deposition that occurs
40:53 the initial rather at the initiation of slop, that's our mass transport
41:02 But as it expands, we begin cover that, uh we are aware
41:07 we will begin to cover that with the deep water deposits uh that we're
41:15 interested in. Uh We actually talked one variation of the theme when we
41:21 at the, the Wilcox in South on shelled deltas and the, the
41:29 of a swamp followed by the filling that by a delta. OK.
41:40 We also can talked about failure that occur when the delta propagates beyond a
41:50 shelf edge. Now, this story that shows that failure will occur
42:01 OK. And then eventually we'll have and more sediment following it. Doris
42:13 suggested this in my scene of the of Mexico back in the 50s.
42:19 . The recognition of certain types of now this failure can be small or
42:26 the case of the coastal plains, can be a regional growth fault system
42:33 extends for the whole extent of the show. And so here's some examples
42:40 that. Uh we've got a uh here, a failure here and,
42:48 notice the failure was initiated at the edge and that failure resulted in a
43:00 transport complex that was then covered. another failure covered another failure.
43:11 So these are, are quite Now, when you think about ways
43:18 get sediment beyond the shelf, certainly whole line of collapsed shelf edges is
43:28 way, another way is to create point source, which is a
43:36 Now, obviously, as we talked that canyon doesn't start as a canyon
43:42 , it has to work its way . But once it does that it's
43:49 a source. Now, some you can basically the source can come
43:54 the shelf edge, those are shelf deltas. And in other cases,
43:59 source can come to the shelf edge having sediment provided by longshore drift.
44:07 , that could be a contour, that or rather an oceanic current that
44:12 onto the shelf. And we talked that with the so a shelf in
44:19 Africa where the current uh comes on and then can provide sediment uh going
44:27 the shelf. So these are all of which getting sediment into this.
44:33 slope and beyond, uh Monterey Canyon longshore drift. It's not really at
44:44 , at a delta hit, it longshore drift. Um That would be
44:50 like this Mississippi Canyon today. Uh not transport much sediment. It was
45:01 a good example of a retrograde system intercepted uh an earlier Pleistocene low with
45:11 Mississippi, the Congo inter is basically a, a submarine canyon in its
45:24 and, and this is something to in mind that we don't have to
45:30 a low standard of sea level to sediment into and beyond the shelf or
45:37 into and uh uh a submarine canyon bypass the shelf. OK. So
45:43 is a high stand feature. These are big. Uh Here's the Grand
45:50 Monterey Canyon, Mississippi Canyon. These the same scale as the Grand
45:56 Um And some canyons are even larger that. Um There's a recent uh
46:05 , I'll, I'll talk more about later. Um The most recent.
46:12 . A compendium of articles about deep systems was just published a couple of
46:19 ago, actually last March. Um um I can't remember the uh here
46:34 so when you see Russ uh Rusian all, that's from this publication,
46:41 . I can't put that uh in reading list because I'm not allowed to
46:47 it. OK. Uh But we'll about that later. Uh Here is
46:53 example of a single thread canyon typically the mouths of a large river that
46:59 be the Congo, for example, could also be the indus delta,
47:03 could also be the Jiu Delta. there is a canyon that basically is
47:11 , cutting into bedrock has got tributaries it's often structurally controlled Monterey submarine canyon
47:18 excavating a bedrock fault. And then Mississippi Canyon is a large scale canyon
47:25 is being modified by side slumps in mobile substrate. And on the
47:33 you see the, the model where have a bunch of little slumps,
47:38 canyons, they begin to merge uh eventually they become amalgamated Into one large
47:52 . OK? Yeah, let's think the Gulf of Mexico for a little
48:02 . Here's the Mississippi Canyon as big it is. It's small compared to
48:07 of these other canyons. Uh So got Plio Plyo submarine canyons all over
48:14 Gulf of Mexico and the they are these big ban systems, which is
48:24 what we refer to as the Mississippi . OK. And here are um
48:29 ship breaks at different times. Now, here actually, yeah,
48:39 , the here is late pliocene to . If we go farther onshore,
48:46 get into some Paleocene canyons like the canyon at the Lavaca canyons shown
48:56 cuts into delta front deposit shelf delta front and it is forming at
49:04 shelf edge of what is in essence ancestral Colorado Delta. There's another ancestral
49:13 delta that's feeding deep water fans and merge to form a submarine fan
49:24 That is the Wilcox equivalent of the fan today. Yeah. What I
49:41 to that? Ok. Uh, little younger. Uh, and the
49:51 is the Yoakum Canyon and its channel is mud and it's several 1000 ft
50:02 mud. Ok? I ran into in the Miss in an ancestral
50:08 I'm sorry, ancestral Monterey Canyon Where was looking at well, logs and
50:15 were basically shallow water deposits or let's say, Sandy deposits. And then
50:21 of a sudden the well log had ft of mud and what we had
50:32 was an ancestral butt. Can you of Monterey candy? Well, here
50:40 got that deep canyon fill. The Canyon, which is shown here and
50:49 we have shelf edge collapse and here feeding again a younger, um,
51:02 lower color. Yeah, that should been middle Colorado anyway, uh,
51:06 feeding another, uh, portion of Colorado system, this merging to form
51:15 fans. So the, the Lavaca Yoko represent large failures of the Paleocene
51:29 of slope edge. We have them the Houston Delta. We have them
51:34 the Holly Springs Delta. That's, the way is the ancestral Mississippi.
51:38 got them in the Lobos Delta. the ancestral Rio Grande. And we've
51:42 them all along here down in um, uh, rather in
51:50 um, Mexico. Something happened at time to cause the shelf edges to
51:59 unstable, most likely related to changes sea level. Uh, but there's
52:07 a one, uh, time or , there's not a singular event.
52:12 , it is rather a singular It's something that happened all along the
52:17 margin. Now, the other thing note is that not all canyons make
52:27 past the sh or onto the there are some small slope canyons that
52:37 do nothing more than erode whatever is the slope, most of which is
52:42 . So those are mud rich canyons do not produce a submarine fan.
52:51 canyons that produce the submarine fan have cut onto the slope and intercept either
52:59 delta or longshore drift in order to a sandy fan. Now, one
53:09 the things I'll point out look at aligned potholes marks. This is back
53:19 2011, 10 years later, we've a paper coming out showing how linear
53:29 uh pot marks appear to be the in which slope channels are initiated.
53:41 . And this is one of the things about being outside the industry.
53:49 People know about things way before they're . And so there's little hints in
53:56 papers and then finally, it's released publication. OK. So we see
54:02 pock marks, maybe gas generated, something else that begin to align themselves
54:08 create these And in essence type one mud rich shelf fans that some,
54:19 of which may eventually amalgamate to become uh type I'm sorry. Um These
54:27 a type of twos moving into type . You can see why I hate
54:32 use the terms type A and B and two. I get them mixed
54:39 . Here's an example of a canyon although it's not in the river's mouth
54:50 is getting sediment from the Ganges The thade dominated delta, the highest
54:58 of accretion uh almost 10 cm per is occurring right here in the head
55:07 the delta or rather in the head the submarine fan. OK? So
55:13 getting a lot of sediment loading, fan moving herds and other sedimentary gravity
55:20 off offshore. Same thing is happening . You got a lot of longshore
55:26 that's depositing in the head of the submarine canyon that has created submarine gravity
55:34 that are active today. Now, idea that some canyons, the heads
55:48 some canyons are restricted to the slope some go all the way across uh
55:55 a snapshot in time. But the thing that can happen is during a
56:00 stand, you can have these small that might even intercept the slope.
56:08 mean intercept the shelf but don't intercept source of set I'm sorry. Sandy
56:18 only some cut across the entire shelf would be like the or the or
56:26 Con uh Congo or Monterey Bay. canyons will deposit a fan during high
56:37 . But as sea level drops, though smaller canyons begin to intercept the
56:46 source, so now we begin to an amalgamated sand fan. That is
56:55 compilation. All of those. During the times when there's only a
57:05 stand, intercepting sediment, there's no to the shelf edge. OK?
57:12 still getting fans develop. OK. the canyon. But those fans are
57:23 by on lap, on lap of lower slope or on lap of the
57:29 because the slope is not pro OK. Remember it's a high
57:34 On the other hand, with shelf deltas, we have the possibility.
57:42 of all about a lot of fragmentation that forced regression and the slope or
57:49 shelf edge better said programing see or mover. And so there we had
57:57 on lapping wedges. So the nature the low stand, I'm sorry,
58:02 nature of the basin floor fan can a toe of slope or this type
58:13 basin floor fan depending on whether or you're intercepting sediment during a high stand
58:23 intercepting sediment during a low stand. ? OK. Let's look at slumps
58:30 , and the resulting mass transport complex a little more detail. OK.
58:35 basically have a failure, a glide a sheet in compression. Now it's
58:44 look something like this extension and lateral movement and accumulation into series of
58:57 lobes. And this is actually this , although it looks an awful lot
59:05 a sub aerial slum uh was first from uh fiords in uh Canada.
59:14 . So it's actually derived a detailed scan and uh high resolution seism.
59:23 , some of the features, first all, that whole slot feature is
59:29 be called a mass transport complex. gonna see a lot of surficial features
59:38 longitudinal shears scows. We're gonna see compression lobe with little thrust faults and
59:49 lobes. And we may even see few cases where we have some out
59:53 . I don't have a good picture that, but I've seen it.
59:57 . So here is that those um scalps, OK? You can't see
60:04 well here, but depending on how change the angle or what you're looking
60:10 the magnitude versus asthma, uh you accentuate these OK. As we go
60:18 slope, we see the crescentic Again, you can see them differently
60:27 different types of techniques. And if take a cross section, we'll look
60:36 this in more detail in a Uh you get the uh thrust
60:41 This is from the permian of the Basin. It's more of a sandy
60:46 here. We have those overlapping lobes nicely uh developed in a more muddy
60:58 . These are more mud flows. The arrow is the direction of uh
61:09 . Uh So it's basically flow. would be the head was this is
61:15 down depth portion of these overlapping OK. OK. Uh Again,
61:23 is one of those later or failures it looks all the world like
61:32 a lateral spread that we might get land. Uh This particular one is
61:38 from a landslide into sun. Again, going back to the uh
61:47 the surface features of these au or lobes. And here we have little
61:54 falls and slumps. So that's what getting here with the AU lobes and
62:01 little reverse FTS and we can see here and we see him here and
62:22 are people from scale and this is playing. OK. Uh Now there's
62:32 variety of seismic face for these, not gonna get into it. Uh
62:37 not something my concern is much. They're usually uh muds stone dominated uh
62:47 they can transport sandy materials, sandy and so locally they could in fact
62:57 uh potential reservoirs. And if you when I showed that retrograde slump along
63:05 slope, rather the slope edge onto shelf. I showed in some
63:11 there were massive blocks that were left and those are local fields even though
63:17 completely uh covered by muds and they part of a failure. So mass
63:24 complexes can include large blocks of preexisting material, for example, maybe the
63:32 front of that failure is a potential . The other thing that happens is
63:44 a lot of topography that it is the sea floor as a result of
63:52 , these failures. And so they to be local bases in which turbos
63:58 be trapped. And among other things be uh can fill and spill sp
64:06 spill. Ok. Now having said we also get salt Ecton that can
64:14 a complex uh Botham Mery and uh create a fill and spill fill
64:22 spill in these isolated bases. Uh in the *** Delta will do the
64:29 thing. So, mobile substrates uh important in part because they create this
64:40 bottom topography that can confine our sandy . Now, the other thing is
64:49 that the self margin can vary uh strike. So in some cases
65:03 uh during a low stand, uh of these, we're feeding a big
65:13 uh down here in low stand, were being fed by longshore drift and
65:24 other areas, they're being fed by failures. So if you're looking for
65:37 water reservoirs, the failures themselves are of interest except they may be the
65:49 of a younger conduit of sandy material those failures began to retrograde onto the
65:58 margin. Now, the low Hebrew Delta had a whole series of
66:11 slope um canyons and this little checker is for levied channels. And unlike
66:30 deep water systems, although there are along here in which sand accumulates.
66:40 lot of that system is actually intercepted a sea valley that deposits in the
66:46 water fan significantly offset. Ok. The Yukon Delta has something similar for
66:54 of the sand of the Yukon Delta is resuspended, goes through the Bering
67:00 and is deposited off of from Russia the S C C. The ***
67:09 is a great example of a slope system or rather uh a shelf edge
67:17 system that consists of a series of channels. I mean through uh canyons
67:27 are in their lower portions levied. we're gonna look at a lot of
67:34 examples to see about the significant uh of oil and gas of the
67:45 Now, the shape of the channels at least in part a feel of
67:55 function of the drain size. The is most of the channels that Galloway
68:02 talking about is actually not talking about canyons but rather the channels within the
68:12 . So uh this is a bit . I probably should delete it because
68:19 always have to explain my way out it. Uh But what we can
68:23 is that when we start looking at channels within the canyons and beyond the
68:31 on the lobes themselves, they change shape and that change in shape is
68:39 impacted by the change in the relative of suspended sediment to be OK.
68:46 I kind of filed this for future . Now, one of the things
68:50 do see is that these deep water start with canyons that erosional and then
68:58 to fill with the erosion aggravation and essentially are all aggregation. And this
69:15 dip sequence is what we're gonna see we go down dip of say,
69:21 of these chips. The other thing note is in these up dipped
69:30 the turbidity currents are completely con confined we go farther down depth either onto
69:38 slope channels that are still erosional in . The her bid currents are high
69:49 , you think can be hundreds of thick that they can overtop the canyon
69:55 have deposition occurring uh on top of canyon walls as, as external
70:05 So here's our in size canyons that be this here. We're getting into
70:11 levee complex that would be this and we get down into a distal
70:18 This is the working model for much which I'm going to be talking about
70:24 for the rest of today. and these are just the some of
70:29 is attacks and the like Galloway is into the E logs that's useful,
70:34 I'm not gonna focus on that here's another system for describing the same
70:46 and here's a cross section through here the formation of this outer levied system
71:00 the and here's the channel and there's a little inner levy as this system
71:09 migrating down the system until his opens into a deposition load. So here's
71:20 confined here, it opens up and it's a low. So we'll look
71:26 that transition. Uh With time here , this is kind of some cross
71:33 of what it might look like. this is where I wanted to mention
71:37 the Deepwater Sedimentary Systems book. It available as a, an ebook or
71:44 hard bound copy. It's really It's like 100 and 50 bucks.
71:49 expect it to get cheaper. It's been released. And I'm hoping uh
71:54 will be a discount for students uh some point. Now, one of
71:59 things that I like about the book is that it's up to date.
72:05 notice here we have our channel leage move again, but look what's
72:19 It's being reworked, my contour rights currents. So it's showing some of
72:31 reworking of these con of these sand by the contras. And notice as
72:39 rework, the more distal portion of lobe, all you're doing is reworking
72:46 . When you're reworking, the more portions of the lobes that are more
72:52 , you're getting sandy and in between mixed. And so again, this
72:58 be some of the asymmetrical patterns as take cross sections through the in size
73:14 , the levied, um, levied and then the down dep load.
73:26 . Now there's a beautiful study by Arter and others. Um, I
73:32 from a, but I'm not Um, and what they're doing is
73:37 , they're looking at the Mo Mo Straits and here's the Mola,
73:43 Moca Delta. And we're looking at low stand delta right here and
73:55 so we're gonna look at the shelf when this was a low stand
74:03 the channel and bass and floor in cross section. Here is a shell
74:16 in slope in the basin floor. was a second pro then there was
74:23 transgression, pro gradation, transgression, gradation, transgression pro gradation. So
74:31 is like the third cycle down. this is a shaded relief map.
74:40 ? And this is actually of the day floor. But one of the
74:44 that's really useful about deep sea sediments that hemi pelagic sediments will drape preexisting
74:54 so that we see evidence of a channel that's been covered with a significant
75:07 of Hemi plan sets. Yeah. what we're gonna do is we're gonna
75:13 some cross sections uh through that channel in here and here we have an
75:22 channels. Here we have some erosion a little bit of deposition.
75:32 And if we go a little farther , we're gonna switch gears and look
75:36 this system here and we're gonna look it from the shelf edge down the
75:46 canyon to the basin, a basin . Now take a look at this
75:56 here. This ridge is a tow thrust of shale. So we're still
76:04 at a mobile substrate. But the up here resulted in this tow thrust
76:11 here and it tends to constrain the and then opens up again into the
76:19 floor fan when we get past the . So if we take a time
76:25 , we see this is actually the front in these little channels or little
76:33 front channels. This is the shellfish and notice these little channels merge to
76:40 a larger system is actually cerebral that active and then they come past that
76:52 thrust and they open up into a compound uh dew um basin for
77:01 OK. It's a sand rich unconfined floor fan and that's during the low
77:10 . And this is kind of a of how uh arm uh arm uh
77:17 we look at this gullies, channel complexes, lobes and fans.
77:30 . Now, as the late low , as we're beginning to have see
77:37 rise in sea level, we're seeing shut off in a lot of the
77:43 source of the shelf edge delta, shelf edge delta is beginning to
77:48 So we're getting a more of a source. So now we're getting meandering
77:58 levies and the fan if you like a much smaller narrow fan.
78:06 So let's take a look at, it up here. We're getting all
78:15 this is later. Ignore that uh getting a lot of channel fill.
78:24 ? As we get down to the f, look what's happening. Um
78:28 is the innermost part of the that . This is actually that lower fan
78:38 now we get the upper fan. lower fan was that early sandy basin
78:49 fan. OK. Uh Here is lower fan here and that more money
79:00 complex fan and the outer fan just little bit of mud. So what
79:12 looking at is the outer fan. the um yeah is the earlier fan
79:32 stand sandy fan and then the more fan migrating on top. Now,
79:43 armor trout has suggested is that this the pattern that we get. Uh
79:50 get mainly erosion and fill, then get erosion and deposition and then we
80:02 almost all deposition. This is that fan. This is that later
80:20 the channel Levy complex. OK. let's look at that a little more
80:25 . Here's that toe thrust again right . We have the fan moving from
80:33 confined to an unconfined S I'm the the turbidity current. So the
80:39 levee system opens up to the fan we have this big band develop
80:51 that channel levee complex migrates on top that fan. So in one
81:08 what I showed here is upper fan , it hadn't even reached the upper
81:17 yet. The upper fans way down , it's still the channel levee
81:23 This migrated over that older fan. we're gonna see that and deal,
81:31 that that is extremely common. That's pattern that we get in a lot
81:37 deep water settings. Now, that levy complex is pretty similar in systems
81:51 over the world. Ok. Uh are the face, she's track.
81:57 you like is a meandering submarine we get crevasse plays, we get
82:06 uh and then it a grades and through time. But these main
82:14 we're gonna see time and time And when we first saw it,
82:19 first began to think about this was we began to look at side scan
82:25 of the Amazon submarine fan system over , particularly the upper fan. Let
82:35 just add for a second. This area here. Oops. And here
82:45 are mass trans big slump ed Ok. Here are channel levee
82:55 Here's the outer fan, your lower . And what we saw were meandering
83:02 of different ages. Uh Basically this the youngest And there was this one
83:09 there was this one and there was one and this week, this
83:13 So we've got what is analogous to distributive system, but it's a submarine
83:26 . Ok. And so we can to look at these and take a
83:34 of cross sections. And so here see each of these meandering systems has
83:45 funny kind of smiley look or gulling . That's what we saw in the
84:03 family. Um This is called the , uh and this is the
84:18 Ok. Now this package is repeated and over and over. Ok.
84:24 As these fans or as they channel sequences shift their location by a
84:35 Ok. So here's one chap, another chimp, here's another chimp.
84:43 . Now I'm gonna look right here most street. Oh, by the
84:47 , these are mask transport complexes. . OK. This is the Amazon
84:57 now what we have a deep sea cores uh to get a feeling of
85:04 some of the mythologies are that lower or sheet, which is analogous to
85:17 early low stand Sandri basin floor fan uh is, is called the heart
85:28 amplitude reflection package. And these things when, when you look at
85:34 the E logs, you see there's lot of thick amalgamated sand sand packages
85:40 to 35 m thick. OK? you have the channel it faces itself
85:48 this is the has high amplitude the hard and they're gonna be more
85:55 , but they will include some good good uh sands. And then finally
86:02 get the levee and over back, is low resistivity faces that are basically
86:08 thin bedded course and fine material. we're gonna look at a lot of
86:14 about this, but we could only one call on the Amazon. So
86:23 have to go to onshore analogs and densely drill levies to, to fill
86:30 the blanks here. OK. So the Amazon fan, here's that
86:42 here's that vertically accreting channel levee complex notice on underneath it is a mass
86:52 complex. OK? The in this area, the slump is the greatest
87:07 but More sandy deposits are almost 30% this section. So let's look at
87:16 in map view, we got these summary channels. We've got laterally accreting
87:26 cutback point bar. We even have off loops. We've got slumps,
87:34 got something in channel bed forms. other words, when people started looking
87:41 these things doing time slices, they to apply seismic geomorphology and say,
87:47 know, these things are amazingly like streams. You can apply the same
87:53 of geom morph characterization to them. as we'll see with significant differences as
88:00 , but one of the things is do migrate laterally so we can look
88:05 it here and look at uh this here, low direction. OK?
88:22 what we're looking at here, here's sketch of what that was when you
88:31 this, you think sweep or rather it's called uh in submarine fans.
88:43 you see this for this, you swing. Now we've talked about that
88:59 as translation and expansion. I wish could use the same terms, but
89:04 are describing the same style of migration , accreting packages of uh point bars
89:15 deeper water gravity flow deposits and even me under cutoffs banded channels.
89:31 So here basically is looking at the in which these things migrate.
89:39 when we're talking about rivers, we at a similar fluvial systems. We
89:48 something at my Saints Adams in Indonesia were fluvial and how we could use
89:55 seismic pattern of the of the point deposits to get a better feeling for
90:02 connectivity of sand deposits. And we do the same thing here by looking
90:09 the pattern of migration to see how potential reservoirs and seals are connected through
90:21 . So here, for example, that laterally migrating package? OK.
90:31 I remember talking to a a shell Back in the early 70s saying,
90:37 know, we we can actually see the high resolution the laterally accreting
90:43 He was actually thinking about fluvial deposits And I said, show me I
90:50 see this and I had to wait 30 years. Um but here we
90:59 a departed system. I'm sorry. This is a point bar. This
91:11 a, I honestly can't remember if is a fluvial system or not,
91:19 this, by the way, is of the answer to your homeworks whether
91:24 exam too. Uh this is its accretion. This is what it looks
91:29 in more detail. OK. one of the differences though is the
91:38 of those laterally accreting packages. In cases, their alternation between high concentration
91:51 and low concentration turbo. Notice in case, they, they merge
92:02 they're muddy all the way to the here. It's amalgamated high concentration,
92:11 density uh turbidity currents. OK. this is one major difference. I
92:19 if I asked you to compare laterally rivers with deep water meander shells,
92:32 is certainly part of what differentiates those packages skip this. Here are just
92:42 pictures. Field examples from the Jackson in Arkansas of that lateral accretion and
92:54 of the lateral variability. And uh in seismic. OK. Notice
93:05 here, there's a little dark zone underneath the high amplitude, that little
93:13 zone is mud and then that right fill is sandy. one of the
93:23 that often happens both in rivers and and when they ceased the meander and
93:33 submarine channels, when they cease to , they began to have mud deposit
93:38 they may still have one last deposit . But that's important because as we're
93:43 see in one of the field examples mud becomes a barrier to keep the
93:49 wet, but the laterally accreting deposits the levies which aren't shown here uh
93:57 producers. Now here is lateral accretion our Yeah, here is lateral accretion
94:11 seismic notice. There's vertical and lateral at some point, they often begin
94:23 become stabilized and they just accrete they quit meandering, not clear
94:30 but that's often seen. And then a channel abandonment but kept. But
94:36 is what it would look like in size we want. And here's the
94:49 about the ended channel, there's that bright spot right there. Uh But
94:54 mud, it separates the, this from the levee deposits. OK.
95:02 that'll be important later. And also how much topography is still preserved by
95:10 draping. And the last thing you a little sand here, this is
95:22 inversion of topography as the sand doesn't as much as the mud on either
95:30 . So what was this? It that? So this picture here,
95:48 this is lateral migration from below and vertical migration above. Yeah. The
95:55 with this three dimensional diagram is it it doesn't show any down current translation
96:07 the axis uh or rather the, sines is simply increasing. So this
96:22 be a an example and I'm gonna expansion because it's all I can
96:29 Um The way I want you to about this is this is one example
96:37 how these channels may migrate through If they're migrating through expansion. I
96:44 you to also imagine how they might through time if they I did it
96:55 translation. And lastly give some thought how the submarine channels change imply um
97:11 talk more about this transition of this in the levies later. But this
97:21 kind of the example vertical A This is a fluvial system. Now
97:33 did look at a creating systems chances cross sections. Channel F we had
97:41 rate versus rate of lateral migration versus of abul. OK. So we
97:48 there can be changes OK? But the short term, there's not nearly
97:55 much vertical accretion relative to the rate lateral migration, usually the flu systems
98:09 discontinuous. So that's one of several that you could be thinking. Also
98:18 about the levies and think about what the height, both of the channel
98:24 the levee. Is it gonna be full discharge or is it gonna be
98:28 thickness of the turbidity? Those are different dimensions now, in channel bed
98:38 . Um Well, we, we they existed uh because we've got these
98:43 of high amplitude reflectors in here, it wasn't really clear what they might
98:49 . Uh And it still isn't always . But when we look at the
98:54 Canyon example, again, we had sediment waves that were small when
99:04 enlarged when they were unconfined. And here are in channel bedford that our
99:17 flow regime and in which sand and does deposit and they're associated with hydraulic
99:28 . They form small scale bed forms large scale bed forms depending on whether
99:36 not, it's in a confined channel on a larger unconfined surface, either
99:45 a lobe or a levy. And are some of these sand wave or
99:51 sediment waves that migrate upstream up flow . Pardon me, uh that have
99:57 recognized for a long time. And fact, in some cases represent contour
100:06 and we'll just skip that. So the channels are meandering and by the
100:13 , the channels can be relatively straight too, we'll talk about that transition
100:19 , but there's also over bank Ok. So let's look at those
100:25 bank deposits, look where they're for and particular, look at this
100:43 this area in this area, it's the outer bend of a meander
100:54 I'm gonna come back to this, gonna reinterpret this uh to be contour
101:02 these, the reworked levies and uh uh that wasn't in the original
101:16 They certainly are sand waves, upper regime. Um This is a fault
101:23 . Ignore that, but we'll come to that idea. I want to
101:27 on these and these are, are spillovers where the upper part, less
101:43 turbidity current, the low density or concentration of turbidity current ends up spilling
101:49 the levee when there's a turn and the more dense flow. So we
101:58 what we call flow stripping and we progressively stripping the upper part of that
102:08 of turbidity current of the minor material then we get this amalgamated, thick
102:17 , thin bit to mud stones over . OK. So some of these
102:26 can still have enough sediment to be . But the most dense high concentration
102:35 turbidity currents are still confined to the . So here we have these san
102:44 units. OK. And they're pro potentially productive. Yeah. So here
102:53 these wash over lobes. There may some crevasse plays. Here is the
103:01 and again, this is here, is that older park that older Dan
103:17 are some examples again of sand Um I would simply add that at
103:24 some of these are probably rework We see him all over including the
103:32 in Nigeria where they been recognized forever being migrating upstream. But um it
103:45 only recently we started to record them these would be the more distal port
103:52 these would be analogous to the more portions of contours. And I don't
103:58 that you can tell the difference uh discal conor and distal lev except geometrically
104:06 currents and in a larger complex. these levies are in some cases,
104:14 reservoirs, sometimes called low resistivity They're a major architectural element in large
104:22 systems and actually smaller fan systems as . And they are associated with other
104:31 uh potential uh faces including channels and underlying uh harps or underlying lope
104:42 I just mentioned in passing, there crevasse plays So here's one of those
104:50 , those plays can like rivers begin be more long lived and here's that
105:00 lobe and as that lobe is that then becomes that lower heart
105:08 Ok. Uh We can do time to actually look at the growth of
105:17 crevasse play just as we took time to look at the growth of
105:23 Mississippi Delta play. Yeah. Now, here to reiterate, we
105:35 that low stand fan sand rich, have that more recent, more muddy
105:48 . So if you draw a cross right here, this is what we
105:55 . The lower fan harp. Notice chaotic debris flow underneath, come back
106:04 that channel levee system, debris flow fan love. That's what we saw
106:29 the Amazon. That's what we see over. And the suggestion here is
106:37 the initiation of a channel sequence is preceded by a mass transit um mass
106:45 complex which suggests Slum Canyon early Fan channel system abandoned. That's the sequence
107:03 I mentioned on the first slide. . And this is the pattern of
107:10 that we see from that sequence. , if we look at this,
107:18 channels or this cross section here, what we're seeing here. Um Here
107:26 got a channel, it's cut out . Here's a mud Drake you can
107:38 here is the ARP. This is frontal display. Here's the mass
107:54 here's the levee and this turns out be another debris. We'll ignore
108:03 Look at the E logs and the . I mean, I'm sorry for
108:15 Levy Chim. It's very diagrammatic but , it's a pretty good reflector on
108:26 way in which the sand is packaged is a relative measure of potential quality
108:34 the reservoirs. If we look at levees, one more thing, we
108:41 a surprising amount of slumping even though a very low relief feature. Although
108:49 can be slumps on the interior, proportion of the levee. And we
108:55 get these types of thin bedded not quite sure what they are.
109:02 were just named by what they look . Turns out uh here's a picture
109:06 some turns out, these are almost in most cases or in many
109:10 contour rights. So again, Levi contour rights, these are gonna be
109:16 proximal levy and proximal contra may be to tell apart if we look at
109:23 Mississippi fan, um entrenched middle fan lower fan. OK. There are
109:47 the let say this channel system, in the upper part, has not
110:03 laterally too much but has vert vertically through multiple cycles of Glacis static cycles
110:11 fall of sea level. Now notice as we get down into, we're
110:22 look at say three, four in , these are the most recent deposits
110:33 stage. one channel is wide, is narrow and sinuous. OK.
110:46 we're getting is a increase in sines a decrease in width. This is
110:55 many ways analogous to a great its . In any case, the channels
111:02 overlapping, if not an estimating this integrated into a meandering channel levee
111:13 . This sequence is really common again over the world. Now, if
111:20 go a little below this sequence, actually get gravels. So literally 1000
111:29 offshore, we're getting gravels being transported some of these oldest lowermost grav uh
111:39 . OK? Now, we know lot about OK, the um Deep
111:49 system by looking at uh Africa and particular, looking at the *** delta
111:57 it has a whole series of the channel systems and we're gonna look at
112:02 right here. It's the ban in channel. Mhm And this system
112:20 we're gonna look at a cross section there's an older channel that was um
112:31 by evolution, think of the OK. Uh But let's look at
112:37 system right here. Here's the channel is actually within it. Some
112:56 an excavation and what I want to on is right here, lateral
113:03 the upper mood and then tail OK. So we're gonna start looking
113:19 this transition from here up here and particular, look at the meandering system
113:34 the inner levies and slops. You this kind of arcuate sides over
113:44 These are all individual slopes. Now, we can trace individual river
113:56 . And when we do that, see that the lower course as a
114:02 of superimposed low stenosis streamss may be as we go higher and higher up
114:13 increases, wavelength increases radius of curvage . That's the Mississippi all over.
114:28 . If we go down to we can look at some channel
114:36 Uh I forget which one it I think it's this one but it
114:39 matter. The green channel complex did same thing. You can look at
114:46 youngest and you can actually see all laterally accreting uh laps when you say
114:53 cutoffs. But we can also look it through time from here to
115:08 Straight crested, straight crested is Angola , Mississippi. Other areas as well
115:22 pattern of evolution of those channels as a grading is reflecting the change in
115:33 amount of bed load to suspended That's what Galloway I think was thinking
115:41 he talked about the effect of sediment on channel morphology. OK. We've
115:50 channel levee systems all over the They just differ in size. Here's
115:57 , we're gonna look at that Let's go from Mexico, the
116:02 Zaire, Rome Amazon be they're just literally everywhere. And basically,
116:13 a canyon, there's an channel levy with an outer levee and an inner
116:21 belt in a terminal mode. This our kind of mental framework. And
116:30 look at that transition here here. here's our base a lobe, here's
116:41 channel, here's our outer levy. . In the channel film, this
116:53 the story eight. Here we got up here. It is interpreted.
117:11 things all begin to look alike because similar process like saying all meandering rivers
117:17 to look alike. They don't but they have so many similarities,
117:21 can combine them. Now, this diagram is from Morse and is based
117:30 on crop da. But it's an to um provide mythologies in sedimentary structures
117:47 a context based on seismic. So it's a big the channel and
117:59 levy. Look at those, those the valley and they migrated laterally then
118:13 , we've talked about that. And the canyon, we have these larger
118:25 levies and then we got local breaches Reba blades, sand waves on the
118:33 on the levees. Mhm. So , let's see what those might look
118:43 . This is a little more detail . Let me look at this one
118:51 . OK. Here's the channel OK. We'll talk about what that
119:01 there. I wanna focus right now and it's gonna be basically sandy deposits
119:06 la laterally migrating deposits. Let's look the levee up in here.
119:15 let me go to here. We've got this levee growing like
119:27 That's what this is showing here. got a couple of little crevasse plays
119:35 here. We got some sand waves in here. Here, the
119:41 there's some slumping that's going on. local slumps on the margins here because
119:51 steep, particularly where there's a cut will have a mass transit deposit at
119:57 base of it. We see this in meandering stream today where the cutback
120:04 in that slump, then is found the bottom of the channel. We
120:11 those uh or rather, we saw in the canoe formation where there are
120:16 big chunks of over back deposits, fell into the base of the channel
120:22 slumping. That's what these are. can. So let's see what these
120:30 sheet are. OK. And in , we're gonna ignore a because a
120:37 the channels uh deposits the lapse and on the levee. OK. Um
120:52 got hetero lithic deposits. one through and that is, oh, I
121:01 to look at the color again. That's gonna be here. OK.
121:10 the more proximal parts of the levee hetero lithic we get up into here
121:30 the upper proximal, we're getting into beds four and five. The distal
121:43 down here. I I do that . I having a hard time seeing
121:49 the hetero lithic faces are down here the sandstones are full and then as
122:05 grade upwards, we get into silt . So there is a lateral and
122:18 vertical change in the levee. I'll this again while I can explain it
122:24 little better. The lateral change goes proximal to distal and that's course to
122:33 , the vertical change is going to going from or to five course to
122:52 . So I was both finding upwards finding distantly, OK. Some variations
122:59 the theme might be these rework sand which increasingly we're seeing as possible.
123:06 Rs. OK. So here's the levy and we can break it up
123:14 the proximal part, upper and And that's gonna be coarser to find
123:25 distal portions is going to be interbedded lithic. So here we've got that
123:41 to find, to verify crevasse plays . Um Here sediment waves could be
123:52 , abandon channel drinks. OK. is a a pattern we see for
124:01 external levies both vertically and laterally and the sand waves. Well, we've
124:08 them before. This is what a wave may look like an outcrop.
124:15 wonder we can't see it. They're distinct in seismic, but they're so
124:22 and even these are large. Um the wavelength here is on the order
124:31 maybe 100 m at most. Oh like tens of meters. They're clearly
124:40 upstream but they may, they may be the flank. You may be
124:47 looking at this. Yeah. So not gonna see these in the
124:56 OK? You may see a channel right in here, cutting the
125:05 OK? And if you look at , yeah of the lower proximal
125:18 yes, binding upwards. And the is finding upwards is because when it's
125:31 formed, the canyon and channel were and so the coarser material could spill
125:42 so that we get course external That's right here. As that levee
125:55 , it cuts out more and more the turbidity current. So we're getting
125:59 and finer finding. OK. that implies that the canyon in which
126:14 turbidity currents or filling has continued to even as this channel is migrating,
126:34 is here, we have a migrating down here. So the outer channel
126:47 been around and is a larger scale older feature sense than is the channel
126:56 Neanderthal complex. That's why there's an led the in and outer look.
127:02 outer levee is where the canyon is spilled over as the canyon fills,
127:10 still canyon spill. So the outer continues to grow. It's just finer
127:19 . But now the canyon is filling a uh meandering channel which is consisting
127:32 the coarser material, the lower part the current. Now, another reason
127:40 it might change vertically is if the are moving laterally, this is more
127:48 of the inner levee, but maybe because there's a here and if you
127:54 it through here, notice how here's channel channel binding upwards. That's because
128:03 lateral migration. So both lateral migration vertical oh are shallowing of the depth
128:18 or rather increasing of the height of levies is a function or, or
128:24 will control the levee change. this is what I was trying to
128:29 . And I meant to show this notice, even when this canyon is
128:35 , you've got a little bit of and as it continues to migrate due
128:45 meandering that levy continues to grow. here's a laterally migrating channel and it's
129:00 have an inner levy and here it's moving laterally, but it could accrete
129:07 as well. And this is a model, but it works. Here's
129:14 channel, here's the slumping that's Here's that outer external levy. Here's
129:28 internal enter levies as that channel is at the same time as that outer
129:50 is growing. Ok. So here's inner levy and the outer levy.
130:00 . And here's what it looks like a seismic way. OK. It's
130:15 , but it's actually not. If generalize it, you've got these outer
130:23 growing from the beginning early on to end. As long as there's turbidity
130:31 current high enough to overtop it. the levees grow up, the overtopping
130:38 finer and finer grain. The canyons gradually filled with meandering channels that are
130:47 in S S as they get more more money because sea levels beginning to
130:58 and they can no longer, they it earlier over that low shelf.
131:04 mean that low fan, but now beginning to back right beginning to grade
131:11 and fill the channel with fine and material. Ok? And so this
131:17 just kind of a model that bears at at your leisure. Ok.
131:30 gonna, I'm gonna leave the topic you need to spend some time concentrating
131:35 it. Now, here are some channels that turned out to be um
131:45 . Here, you can see the channel systems but they're in valleys.
131:53 here is the valley for one Here's the valley feel for another
132:02 OK. So we're just gonna look one of these, the Sequoia
132:07 That's this one here, I Ok. Oh And this is the
132:18 on we had a lot of segment , but they don't show what we
132:25 assume is there's gonna be an external here. Gradually the bypass begins
132:32 We get a amalgamated channels. It to grow up into meandering channels that
132:45 basically filled. Now, in this , we have a couple of meandering
132:53 . Yeah. Uh That's just a on the thing. So here's our
133:01 where the levies are, but here's massive channel breaking up into a couple
133:09 meandering channels, breaking up into isolated , filling with mud. Now,
133:20 is an idealized pattern from Africa. just left the Nile, we'll come
133:26 to it. OK. The idea channel incision. A canyon incision rather
133:34 , maybe a debro was and channel maybe re incision. Finally channel the
133:48 levy and that's something like what we here. Now, let's let's kind
134:01 break it up in even more simpler . Uh bypass. So maybe a
134:09 growl slops high net to grow stack fill. That's gonna be those wide
134:23 chants grading up into lower net to channel Lee complex. We just,
134:34 can envision that going up to the until finally we get into very high
134:44 top most channel, low sanity, sanity, high sanity, low
134:53 high mud. Hi, Sam. , Sam. Ok. That's the
135:03 turns out this, this mile, turns out this miles all over the
135:13 . The other thing to keep in is that's just one incision fill event
135:21 this one or this one or these things can feel larger canyon systems
135:35 time. Ok. So each of is going to be one of
135:55 And so what we can think about kind of complexes where you've got,
136:11 channel feels upward. And then the channel sitting up here, the,
136:29 individual channel is something pretty small that's be in here. Oops, what
136:44 pin is good working. But you the idea of, um, I
136:48 my cursor that individual channel is gonna right in there. Ok. And
137:01 here we've got something for Angola. , now it's gone from West Africa
137:09 Angola. Uh 2018. Uh, now at least can say what country
137:14 here and I think you can see lateral change in these OK. That's
137:24 . Uh these canyon fields because these are long lived features that will be
137:32 conduits over long periods of time, sea level changes. And so these
137:39 lobes uh may also show the the , not only of a lobe covered
137:50 mean channels, but then abandonment, , meandering channels abandoned. So each
137:59 those systems here, he's going to a evil low growth pattern down,
138:12 slow. Is that OK? Let's it what's we can stop the
138:21 OK. Uh This is our We're looking at deep water centers.
138:34 And let's do some variations on the . Uh Suppose, for example,
138:41 have some kind of bath metric uh that causes an area to pond.
138:52 could be a slump or it could uh I any number of things.
139:01 what it will do is give us is an intra basin loa as supposed
139:07 a basin floor load. And a of our reservoirs uh are particularly
139:15 on mobile substratum are actually not base lobe, but rather intraloop lobes.
139:22 . Now, also notice is coming of a confined area into a
139:29 but it seems to he actually course find. So let's look at this
139:38 um moody described a jet in which had erosion and of course uh rain
139:52 sorted sandstones that extended into an area proximal distal lobe. And that is
140:03 course, what was also shown with uh turned out moody uh had been
140:09 to some of the Exxon work and , was reflecting that uh in anticipation
140:15 publication. So we see here that , bed load deposition, suspended load
140:25 proximal to dis OK. Now let's a cross section here confined to
140:35 Yeah. Now we're coming through, is down in here high density,
140:42 density turbidity current, hydraulic jump lots turbulence as this thing begins to spill
140:54 . And it's basically gonna be we get a supercritical type of turbidity
141:04 and resulting herd as that transition And we can describe it, we
141:11 look at the back sets scows and also think about where it would
141:19 It's gonna occur any place where we from, confined to unconfined and confined
141:34 under unconfined. And in my we've got these fingerlike lobes, we've
141:43 the channel and these funny scalps. it turns out that in some cases
141:55 transition actually this here the transition is zone for break of slope to the
142:05 and it scoured the dunes could be , ridge dukes and sediment waves.
142:14 this is one of those cases where actually do see dunes forming in sub
142:20 systems. I mean, uh so deep water systems channelized levee expansion.
142:37 . Now it turns out that and think I talked about it.
142:41 Urbanites can be subdivided based on how they are in extending long distances.
142:53 a low efficiency turbo system is sand , low volume. Well, it's
143:01 low volume lobe. It's a Sandri mud, high efficiency, higher
143:11 more mud and most efficient is kind a mud dominated system. Now,
143:20 happening, the more mud you've the less viscous, the turbo is
143:29 of a low density turbo or low and the farther it will flow whereas
143:37 dense, uh, high concentration permitted with no mud, it's just gonna
143:45 . OK. Now, what that is that this area, this channel
143:51 transition can get increasingly wide. Um using wide in different terms. This
144:07 Um, 15 - 20 km I gotta redo that. OK.
144:14 here we've got media dump, scour with uh sediment here. Bypass high
144:30 , low efficiency. So this channel channel lobe transition zone, sometimes C
144:41 T Z can be seen in crawl fault here. And these are the
144:58 and this is the, the, model, OK? That we go
145:11 . I just, just skip It's too hard to explain the time
145:14 . But this is what you could that zone bypass looking like over time
145:26 the accretion of that proximal low. . And again, that's where we're
145:33 at here and here now that scour which includes not only erosion but
145:47 um, um, do like uh will, will alternate a lot
146:00 an Alluvial fan, it's got it from it channelized, unch channelized.
146:11 a lot of the work that's been is relating the flume work of fans
146:19 the inferred flume work of lobes where backfill, flip, backfill, flip
146:29 lobe flipping. OK. Uh I'll you read this at your leisure.
146:34 basically characteristics of these transfer results. . What I want to focus on
146:40 is where those that transition goes from to low. Now, this is
146:47 Congo, this is the channel floor this is the levy crest. Now
146:55 the levee gets lower and lower until merges with the bottom. That is
147:03 said the channel, the levees And at that point, you have
147:11 flow. So here we have those crests in the channel. OK.
147:19 we have the end of the the beginning of the lo. So
147:28 look at something more like a hypothetical uh look at the levee height.
147:38 a second. Um I can't just . OK. Yeah, there was
147:50 to be a line here which is this line here. Um This
147:57 Yeah, yeah. This line here a channel bot. Here's the levee
148:04 , here's the total flow. So density, high density turbidity current.
148:17 this is the channel bottom, levy , channel bottom like the height.
148:27 , right at this point, I've this to the point where the levy
148:34 goes to zero, you know. yeah. I'm sorry. I,
148:49 mean this is the bottom of the , sorry. Yeah, we'll see
148:57 this is in. OK. And is the top of the float levy
149:08 , chow, bottom, top of slope. This is what I was
149:14 around to this. Here is the high density, low density to be
149:39 , can't get this work. Now that turbidity current goes down flow,
149:56 a process of alleviation that causes the grain materials to float to the top
150:04 it spills over any time. The of the levy is less than the
150:12 of the turbidity occurrence. Their spillover lea growth and the turbidity current gets
150:22 and smaller distance. Now, the or height of it high density turbidity
150:33 really doesn't change much but look what right here. The high density turbidity
150:46 begins to spill over. There may still be some levies and there's this
150:50 not what I implied earlier where the and levee disappear, but rather it's
150:57 the levee is lower than the height the high density turbidity current. Say
151:07 fast real time. Uh you drive you crazy. And what that
151:13 is that the percent sand is gonna right about here. This is where
151:25 levee begins to uh or rather the begins to form a sandy lobe.
151:34 , this is a transition point, so much from the channeled that but
151:40 where the height of the levee is than the effective flow or height of
151:46 high density component in that transition will the deposition of a band where uh
152:04 , it'll have that transition be How do I say it closer to
152:13 land if the levee is not very and the Hi den morbidity current is
152:27 high relative to the levy levee. gonna be where you have a high
152:31 of mud system. Think low standard sea level think that lower Harp think
152:44 lower system where you had a sand float fan or basin boat fan.
152:50 look what happens to that transition point the flow turbidity current gets finer
153:01 less sand, more silt. It's seaward. Then finally, it's way
153:09 here. So now we've got this system migrating on top of the fan
153:22 . So here we have transition point low sand transition point I see.
153:33 this is the model that I want to think of. When you think
153:37 this transition, this frontal display, harp and all the details that we
153:46 about in here. Here's that final actually, let's look at it over
153:57 . Here's that transition unit here we that frontal display here, cross
154:21 So basically, this is what we've talking about for some time. This
154:28 here really this to this. So happens when it becomes unconfined?
154:40 we've already talked about the fact that is in a low flow system,
154:44 mean, low sand system, high system, there's a channel levy transition
154:55 . Let's ignore that for a second think about the depositional upload. It's
155:03 described as an access to French. it's a, it's a bit misleading
155:12 we really have these lobes, little elements forming a lobe lobes forming lobe
155:27 and then lobe complex sets sounds very like what we talked about with the
155:36 fly in the jet deposits. These represent short term deposition, depositional elements
155:47 a crate into larger and larger low . So let's look at that lobe
155:56 the low stand here, it was the low stand and here it was
156:04 the higher stand, I say higher . Um when you had the meandering
156:16 covered, OK. Now let's look that upper low and we see that
156:23 consists of a series of lopes and are uh you can't quite see him
156:29 , but you begin to see him packages and I'm just gonna take seller's
156:40 for it. Uh that this, are the packages that form the
156:48 Again, this is just a one of sea level uh pack it in
156:55 here and you can see with the in detail, the information you get
157:04 packet K. Well, it is it's some place. OK? Again
157:12 . OK. Here's that low K a little portion of the larger
157:23 Here's Kay again. And if you carefully, I think you can see
157:31 channels. All of that is part K which is part of the whole
157:49 . Here are again, some more . And Los Los, OK.
158:01 we see that little lobes form big which form big lobe complexes all within
158:08 single period of time in terms of package. OK. Uh If we
158:17 at these salt mini withdrawal basins we see the same thing. We
158:26 lobes, lobes lobes. And if look carefully, you can say distribution
158:44 . In fact, they look something this. So each of these is
158:52 little lobe packet, they had superimposed on top of another looks something like
159:01 . So this is in an intra . No, not a basin floor
159:08 , but it's the same packaging, same pattern of shifting. Uh Let's
159:18 to the Gulf of Mexico. Let's to this area here where we've got
159:22 whole series of basins. There are , many basins, salt withdrawal
159:29 basin, one to three and OK. When we look at one
159:39 those bases, we look at how feels. First thing that happened,
159:46 had a mass transport complex, then began to get dis tributary lobes and
159:55 and then it had his own bypass that lobe was covered by an overriding
160:05 channel complex. And notice the lobe like a finger like right, almost
160:16 . And that's because of these little . And this is something uh analogous
160:26 the what you might uh get, not gonna get into this. Uh
160:32 can look at it at your leisure you're interested about the vertical change.
160:36 the main thing is you go from trans transit to a channel lobe complex
160:44 load complex. And what's happening is a fill and spill. It
160:54 spills, fill, spills, fill and particularly during low stand, it
161:02 erodes. So during high stand, filling, the overflow is the relatively
161:19 grain upper portion of the turbidity currents the courses material being period at the
161:32 first oh first is to fill I'm later. If there's erosion going
161:47 you can get some coarser material. it could go here, capped with
161:56 erosion up here. So the pattern filling from top to bottom will change
162:05 on what the sediment supply is And one of the things unique to
162:10 Aly's gravity flows is that sub gravity can have a vertically stratified turbidity current
162:18 could be 100 m high with a grain portion below fine grain above.
162:26 of that tripartite subdivision we talked about the very beginning. Yeah. So
162:34 we've got a confined channel. It's up until finally spills over again.
162:45 fills up. This is an auto change. In other words, what
162:53 looking at here is the vertical change to a change in the proximity of
163:03 turbidity curve and then it spills over starts again. Here we've got an
163:15 lobe complex where we have changes in , upstream, up current sediment supply
163:24 by external factors will stand. He , for example, it gives you
163:30 cyclicity. OK. So we see an individual lo or rather within an
163:40 time period, autogenic changes and then time, externally driven changes.
163:51 And, and we see that in salt influenced Santo space, just like
163:56 many basins of the Gulf of they'll come in instead of just a
164:03 minded linear split like we saw in Gulf of Mexico doing all sorts of
164:15 . So this is the reality of really complex salt influenced that.
164:26 Uh And again, I'll just uh you look at that at your
164:30 but it shows you the, the that you get the Nile is
164:38 but it's the same story. Here's shale ridge causing ponding down here.
164:49 have that the unit is going from ridge to open. Here's a different
164:58 shall ridge open. Let's look at in detail, we see individual
165:07 So what looks like a axial to banning is really a series of these
165:17 lobes. OK. Skip this uh is a discussion about these intra slope
165:26 basin floor fans. I'll let you at that. Uh I don't want
165:31 go too much into that with the I had left. But let's look
165:38 the submarine fan system of the The this plane lower fan, middle
165:45 , upper fan, Lower fans, harp look at the percent month,
166:00 , mud, even though it's the distal part of the fan, 90%
166:08 Or 95% mud when you're up here the upper fan with the channel le
166:15 . So there are major changes as go and look at these fan elements
166:22 time. Now, let's look at meandering system ahead of the meandering system
166:32 a low. Ok. So each those meandering systems had a low and
166:39 pro graded through time. So here's series of them of these meandering pro
166:51 lobes that were eventually covered with the levy system. Now, this is
167:08 , older. This is that little time. One that's right about
167:19 And now the lobes are regressing and they're doing, they're filling this area
167:32 . They're backs stepping. This yeah, this is something we haven't
167:35 seen before. They're backs stepping because the rise in sea level.
167:45 Dingo fan lobes, Mediterranean fan the bigger lobes, the channel,
168:02 Congo here are some of those big . Here's the modern day basin floor
168:11 . Let's look at one of these , low, low, low,
168:15 . This is how it's extending itself with the basin floor fans, they
168:25 by theories of younger and younger They see it on the all the
168:36 bottom floor basin floor fans in in Bain floor. Same model that that's
168:50 a repeat that wasn't supposed to be . Here's the Mississippi, we're looking
168:57 one part of the Mississippi main Mississippi , an older channel lobes,
169:07 lobes, look at them in more , little bitty channels, little bitty
169:17 . We look at those and we tiny lobes. Yes, me and
169:34 can only see this detail because we're a high resolution scanner of of the
169:42 surface. That's basically what we see . So we see that the distal
169:50 of, we see that these lobes splitting up in smaller smaller lobes to
169:56 their tiny little child chimps like OK. So let's see how we
170:04 approach these from a reserve point of . I've shown you some examples of
170:11 with contours. Let's look at some using this model here, let's begin
170:18 the Gulf of Mexico and there's five that we could look at each of
170:24 represents production in a different portion of model that we talked about. So
170:33 look at the levies first think we this. Um So we have the
170:44 and associated reservoir fishes uh channels, underlying low. Here's our goal and
171:00 a channel and levy notice the levee coarsening rather fining upwards. Ok.
171:15 Globe Levy, all three are potential . The Tahoe field is basically a
171:28 . It thin beds, but they're producing is coarser at the bottom finds
171:36 because all of these little stringers are laterally. Yeah. What about
171:49 Well, I'll have to come back that. Um, these P slope
172:02 come through here, you know, some stuff but um always happens.
172:22 run out of time. Um Uh These are the main traps,
172:27 mean main um reservoirs and they're basically up uh the feeder channel and,
172:38 here's the lobe About 10 m thick it consists of a series of little
172:50 . There's other uh reservoirs in Channels mainly here. So this is
172:58 a channel fed a channel reservoir setting some uh lobes at the end
173:14 and uh the Congo basin and Angola big uh channel aggregate, we get
173:25 series of amalgamated channels. They are , they're in the lower part of
173:34 of these aggregation fields as we go up, we get into lobes,
173:45 as good reservoirs, but because of lobes or bath, the metric
173:52 we have compensation stacking. What we're at here is that model again,
174:04 reservoirs, moderately good reservoirs, no . OK. So that package the
174:16 time and time again, the LEVI in offshore Nigeria. Here's the
174:29 here's the channel, here's that here's that levy. OK. Notice
174:40 levee sitting on top of the OK. Congo, nope, just
174:59 we saw elsewhere. Little bitty fingerlike . So, so, so we're
175:14 at again, lobe reservoirs here in North Falklands, we talked about it
175:21 . We get these digitate globes within lobes. We have 13 lobes here
175:33 this basin, We have four rock , mass flow in T A as
175:46 inner lobe, low density turbo, outer lobe, mass flow debris,
175:56 fringe and non reservoir. The best are sitting here with the VMAS.
176:05 gonna be the proximal part of that low. It's gonna be the inner
176:13 of each of these groups. Here we've got again, the inner
176:24 , those little distribution channels thick oh deposits still good thick, what they
176:41 them hybrid here. Oh Actually, is uh going into grade deposits.
176:53 is the pro grading frontal lobe and see the distal decrease in that thick
177:04 turbo and lateral changes as well. this is the downstream pro gradation,
177:15 or down lapping of that package. this is the kind of lateral packing
177:24 against it. Compensation of hacking. go back to this. Let's go
177:35 to the top, which is a here. We got the channel fill
177:46 . We have a levee and lee . Now, the levee over
177:52 OK. You can kind of see the um e log vertical sequence.
178:09 are centimeter thick sand. So you don't seem like they would be
178:13 but they're producing wells. This is map of the, the field and
178:26 problem is most of the channel is . The production is mainly from the
178:36 . And the reason for that is there's a little bit of a down
178:43 here, a shale at the base the champ and that shale is just
178:50 to cut off the channel deposits. here's the production or the,
179:00 this better, here's our oil and or a gas and water.
179:07 oil and gas and gas on Oil on the bottom, right?
179:16 , yes. So, ok, Ram field, these are lobes and
179:28 at um series of overlapping packages. amalgamated cheat chat for Jay Allen M
179:44 Levy and Amal invaded Saints. You look at that later. Uh But
179:55 the levy and here's the chance the is in the levee. Here it
180:05 here. This portion here, this of the field is in the
180:19 Yeah, these are levy deposits. the channel wet and I meant to
180:33 this. This shows the oil in real thin um levy deposits and what
180:47 wanted you to see, but I to enlarge it is that proximal to
180:53 , fining upwards of the living. . Um Mars in the slope basin
181:04 here it comes in, it's being by a big salt dome. There's
181:14 field, I'm sorry. Uh here's field in yellow salt domes all around
181:23 uh being barrels of oil equivalent seven , the lowermost reservoir series of pro
181:35 lobes. And if you look at in detail, you see those little
181:40 lobes. Ok, amalgamated sands giving sheet sands. Now as it grades
181:57 , we get into more money systems more channelized systems, the upper channels
182:11 more narrow. Here's a low lower , think of it as your heart
182:18 then we get into the a grading migrating on top of the lobe.
182:26 the lobe is an amalgamated sheet sand these are some of the characteristics.
182:34 . Um MENSA sitting here is a of backs stepping lobes. Amalgamated sheet
182:49 that are backs stepping due to a in sea level is tilted uh because
183:00 uplift on so on marsh. Here's field right here and notice the lobe
183:06 this is an individual lobe but the are not always connected, but this
183:15 I think is disconnected. Maybe it's , these are amalgamated. You see
183:20 these lobes aren't always laterally connected and is just one of the areas
183:42 Oh, so it's laterally disconnected. . OK. Uh Amalgamated sand.
183:57 all amalgamated sands, but these are poses with little shale where you're separating
184:03 the um reservoirs and this is um channel cut out. Ok. Sheet
184:18 , channel sands and I'm gonna handle still Gulf of Mexico but supply.
184:32 same idea though older lobe, younger , each lobe consists of a series
184:39 little distributed lobes, the trunk. tributary here insists Over 70% Sandstone,
184:55 , massive sense, chas lobe, massive sandstone, low margin,
185:05 No. So let's look at a real might be something like this.
185:12 might be looking at the trunk, might be looking at the distal lo
185:17 completely different percentages of uh I'm Uh This is your field within that
185:27 . You've got areas that are 90% turbo deposits or den uh debris,
185:35 de uh herb s which are your reservoir to almost not OK. If
185:43 look at the permeability, the red distal, the blue approximately. Now
186:01 some blue that are pretty bad, the reality is your best reservoirs are
186:07 be here in the approximal area. . And part of it because they
186:16 are grained is you approximate the Part of it is because there's more
186:22 , the sandstones are smaller and more rich. This again looks at the
186:30 in grain size and the trunk channels are very good. The channelized lobes
186:40 almost as good. Low margins are very good at all. Now,
186:47 one other thing, the paleogene reservoirs not nearly as good as the
186:58 Now turns out MCE reservoirs are much quartz rich. 82% quarts, much
187:12 with the paleo and the rock fragments 20% vs about 2% here. Now
187:30 tells me there's a change in but there's also a resulting change in
187:38 porosity and permeability. You can look the convection curve for the my,
187:47 doesn't, it stays at 30%. at the compaction curve for the
187:54 it goes down to 20%. And because of the increasing amount of ductal
188:04 better volcanic. And so the quartz zones, sources are not, will
188:15 more of their primary porosity. Then the rock fragment rich. So zones
188:24 because of the ductal deformation, the of pseudo matrix are not as
188:32 And look at the variability of the composition in composition and grain size of
188:44 deep water reservoirs. The same variables impacted the flu system and flu reservoirs
188:53 the Deltec system and Deltec reservoirs in deep fan systems and deep reservoirs.
189:01 start with sources and continue through Di . OK. Now a lot,
189:10 one last thing I'll mention here. is the change in source. Here's
189:17 globe in China. The source did change. What's changing is the fabric
189:25 the texture of the different environments. system. We've got an low
189:35 a near access fringe. We already that those consist of a whole series
189:41 little, little bets. We know the high density turbos here are our
189:51 reservoirs and cous reservoir. They're also decrease in grain size and increase in
190:01 . Look at the permeability and the high density turbos, the low
190:17 turbo. OK. The reality is as we go and bury these
190:28 actually, I'm gonna skip it as go and bury these things, we
190:32 a change in porosity and permeability, because of the composition of the sandstone
190:42 , but because of the amount of in the grain size. So the
190:47 thing I'll end on is this statement Moo and it says case by case
190:57 without preconceived ideas that is models and based on careful core analysis, Integrated
191:05 0D seismic and well logs has opened a whole new, Ran the phase
191:11 research in the industry and company in industry and academia. And I would
191:17 not only 0D but seismic human. current models are still heavily based on
191:24 driven depositional patterns. They're clearly particularly in terms of recent advances in
191:32 exploration. We need to begin to at some of the complexities, one
191:37 which is the role of turbo and fan systems. OK. So on
191:44 , that's all the time we There's lots more to this world uh
191:49 of mythology that you'll just have to on your own. But uh that's
191:54 for this course. So OK, think uh you could figure out that
192:13 there's a whole new, there could a whole course in each of these
192:18 . I used to teach a semester course Deltas and Deep Sea fans.
192:25 , so you've got the rest of career to teach yourselves and take advantage
192:31 any opportunity you got. But, , let me send you the,
192:42 , uh, uh, take home , um, let me, I'll
192:51 over it with you real
-
+