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00:00 Yeah. Anyway, okay. I'm gonna talk about the customs

00:06 but the reality is that you cannot with lakes in isolation. You've got

00:13 look at the context in which they're the adjacent deposition systems and the structural

00:22 reasons for their formation. Now, actually a lot of good literature on

00:31 . But the one that this is of those cases where the textbook really

00:37 a good intro and I'm gonna be some of the chapters from the

00:43 including this one in the country. you'll see these names down here

00:51 in a lot of the figures, also notice there are a lot of

00:55 names because the chinese have really taken the study of the customs systems and

01:06 basins, uh to really the state the art at the President.

01:13 what is it about the custom Well, they don't cover a huge

01:18 today. Um, but they have the past, there are a limited

01:26 in the geologic record. So they're as well studied as other systems

01:33 They contain a large amount of important ranging from oil shales, we both

01:42 and reservoirs, uh, evaporate, rare earth minerals within cold uranium

01:52 So we continue to hold them in high esteem, in fact, even

02:00 , 10 years ago. Uh they about 20% of conventional petroleum reservoir.

02:06 , we really started looking at the in petroleum systems much more in the

02:13 15 years or so. These are some of the areas where we've seen

02:23 oil deposits. So, in offshore , in the south atlantic, all

02:28 china, uh the outer river in Denver Basin, in uh of

02:36 US etcetera. So, we see studies from many of these areas,

02:41 areas uh Indonesia and china and that's the bulk of the petroleum is

02:49 from the custom source rocks. uh these are major uh fields and

02:58 increasingly a major area of interest. the first question I might ask you

03:04 , how do you form a And clearly you need a whole,

03:10 you could block drainage, blocked drains a river. I mean by a

03:18 that would be like uh ag for example, when the continental uh

03:26 sheets began to retreat. North flowing formed this huge lake, you get

03:32 by dunes, uh, river oxbow lakes, landside lava flows.

03:39 Grand Canyon was damned by lava flow lake for awhile, balts. Uh

03:45 got thoughts that would lock off the . Um Most of these though are

03:53 . Um and so if you want long live, like, you're basically

03:58 have to create a whole due to . Okay, um subsidence volcanic

04:07 racial scour really is, is a longer lived result. The great

04:14 finger lakes, but tectonic depressions, rift valleys, foreland basins create,

04:21 sacks. That's really where the bulk our lancastrian deposits in the bulk of

04:27 petroleum interests has occurred. Okay, , 90% other lakes are the result

04:37 tectonics and glaciation. The one of variables that's beginning to sound kind of

04:45 . Well there's geology or whether there's climate and hydrology which is related to

04:52 and geology, which is related to and time and biology. Biology we

05:00 with respect to shale composition, but is much more important with respect to

05:07 customs policies because of the role of productivity in lake systems. So this

05:17 says the same thing. It just a little deeper into some of those

05:23 geology and things like tectonic setting accommodation, space, blah blah

05:28 You can read it, it's all but um it's all important in terms

05:35 understanding the controls on the customs The control systems have some things in

05:42 . A non marine final assembly that of goes without saying no astronomical

05:50 Okay, that makes sense. But can't have wind tides and so you

05:56 have set up and set down during that can generate some interesting environments.

06:03 it's a reduced wave climate, but course that's because lakes are generally smaller

06:09 oceans. But we talked about the sea which is a lake or the

06:15 legs. You got pretty good wave . So wave activity is a function

06:20 the size of the basin and fetch wind over. So for the most

06:26 lancastrian deposits on lower wave energy that but um you can't generalize uh episodic

06:37 and it can really lead to evaporate exposure and related cyclical prophecies is the

06:49 of those very large non use, fluctuations in lego like like Malala in

06:56 east. Um It's the frequency of fluctuations is driven by climate, the

07:09 extent tectonic activity. Um And it's an order of magnitude more rapid than

07:17 changes and it can be greater in . Uh Usually you see an increase

07:27 brain size towards the border, fine the middle will show exceptions paleo currents

07:33 the center. I'm not sure I agree with that. Now. Um

07:38 local sediment provenance that is shared by fans, they both tend to have

07:45 small drainage basins and therefore the local provinces. Having said that as we'll

07:56 , fans and Austrian deltas can intercept and more larger and larger advantage areas

08:04 become larger and larger rivers and have provenances. And unlike marine settings,

08:14 you can produce sediment with a high of oil, but with waxy organic

08:20 , the geochemistry of lancaster in organics different than the geochemistry of marine organics

08:29 I'll leave that for the next course get into detail. Whoops. Um

08:36 need to think a little bit about different settings uh in which we can

08:44 a late uh the littoral zone. the term we use for marginal water

08:52 be the marine or lakes. Uh that's basically the zone to the base

09:00 way, let's say weight base, in this case is also the zone

09:05 mixing because that's of course how you . Um, and then as we

09:11 into deeper water below wave base, getting into the pelagic zone. We're

09:19 deposition a lot of the deposition from center. We can also subdivide

09:25 No, we can use this for classifications to just 10 to into the

09:32 zone. Photo zone is the depth which you don't get significant like

09:38 of more interest is the zone that that's dark below plastic has no life

09:50 therefore no primary voters synthesizers, with death. Yeah, there's a

10:03 here mixing, but I'm gonna get to that in a moment. But

10:08 called the epidemic. And it's basically transition from the upper zone to the

10:18 zone. And this is for stratification stratification is an important variable in allowing

10:32 material that settles in the zone to non oxidized to be in reducing conditions

10:42 allow it to match your it to and gas. Now, if you

10:49 at the organic sentiments here's that epilepsy again, Lord May or may not

10:58 on that later. But below the he has stratification in, tends to

11:09 greater than the rate of decay. it is potentially hydrocarbon sources.

11:18 these here are allergenic, they're coming the outside our sports water bloom detritus

11:31 here. We also have auto jenny that's basically from the softest living fish

11:40 plankton yourself. So the accumulation of bread sentiment is going to be a

11:48 of both allergenic and allergenic resources. a surprise. The allergenic door

11:58 the photogenic sources very dominated are gonna towards the deeper usually metal parts of

12:08 we see here, big ball describing zone fans, they stay here.

12:25 little unclear what's going on here. , I wouldn't know the hot

12:30 So, and uh these tectonic li zones where we have early rifting.

12:38 we not only have early lake deposits the alluvial fans, but we often

12:44 hot springs as well. And uh dr gravest talk about custom carbonates,

12:54 a little. Okay, well they're they're locally very important. Um in

13:05 there are some of the main uh sources and reservoirs in the sub solitary

13:13 , brazil's example. Okay, uh said that I'm gonna kind of pretend

13:19 don't exist because fundamentally I don't like rocks and uh I'll mention them in

13:26 , but just know there's more to and that's one of things I like

13:30 the textbook. I want you to . It's got almost a half the

13:35 is on carbonates. Right? So think about the non uh biological maybe

13:48 . Uh we still have the but now we've got a delta over

13:59 , some of that sentence. So density currents in some cases if there's

14:07 strong stratification, Let me just get pen going for a second. If

14:19 lake is stratified, some of those currents will float out along that stratified

14:27 and some will float as a clue the top. We'll talk about how

14:34 of these may vary. And of , providing sediment either from suspension or

14:42 uh bottom traffic uh related from that viel inflow, uh maybe ice drop

14:51 , a little volcanic added. so there's a lot of different things

14:56 can combined to fill that lake. , this is actually a diagram.

15:04 personally confirm in that. It still that delta sedimentation. It still shows

15:14 plumes of sedimentary gravity flows. It's the biological productivity. It also shows

15:25 that zone of mixing in the wave can cause erosion and re deposition.

15:34 , so depending on the size and velocity, a significant amount of the

15:42 in the lake can actually be um derived as far as the water.

15:54 have sources and sinks of water rain the lake, surface blow from the

16:00 and groundwater recharge from the influx. lose it by evaporation and evaporate transpiration

16:07 surface water exiting and groundwater reach being . So in short, that's what

16:14 in and that's what goes out and lot of what happens in the lake

16:19 the relative water budget. Think of like sediment budget if we have more

16:25 in than out, we've got a open lake, we have less water

16:30 that water out. We've gotta close . Yeah, we'll be here.

16:37 Water salinity certainly is a way of lakes from fresh to hyper saline.

16:45 I'm not gonna talk about that much . I'm more interested in some of

16:48 other aspects of it. Um We talk about open and close perennial to

16:55 pan, degree of stratification and last overfill the under field, overfill the

17:00 filled uh is probably the classification that geologists are using most today. So

17:07 focus a little more on that than we would have in the past.

17:13 let's start with the open she opened uh because there's more water coming

17:21 Um Then the lake can hold as spilling over whatever the seal is,

17:29 gonna have a relatively stable short. can never fill it over the

17:35 Okay, so it's always gonna be the rim level, it's never gonna

17:39 below. So here is the rim . What they call a spill

17:44 Okay, um inflow and precipitation is greater than outflow and evaporation because the

17:55 is constantly being replenished. We mainly solicited classic settlement derived from the rivers

18:03 erosion of the sides. Okay, again here we've got that zone of

18:11 but now that uh this was eroding depositing, here's our turbid ites,

18:17 our delta's okay. And here's our sedimentation. Now down here, the

18:27 are laminated. The mud are laminated they are below the zone of mixing

18:38 the this particular lake or this type lake is often stratified with the more

18:45 water below not being mixed with the dense water above. Okay,

18:53 right in here we've got homogeneous mud laminated. That's because it's oxygenated is

19:04 above anaerobic below. And so what have been laminated mud has been biology

19:12 aging is more massive. In that's the area where we're gonna get

19:17 related sedimentary structures. Okay, so we have an example of what would

19:29 decreasing brain size towards the myth, that really depends on the Botham itri

19:39 the shape of the source or source of the sources in here. That's

19:45 not the case. So in the geometry, even though open lakes

19:51 to have solicit classic settles, they to find with distance from the

19:58 It doesn't always hold that the finest be in the middle. That's usually

20:04 case, but not always now closed , on the other hand, does

20:09 fill past the spill point, more is leading and it's coming yet it

20:21 fill to that level. So as result there's a lot of up and

20:27 movement depending on climatic changes in the of influence. That means you have

20:36 shorelines as the water moves up and and there's a lot of chemical precipitation

20:45 and carbonates. Okay. And it to be sailing tends to be more

20:50 a salih lake then the open legs tend to be fresh. So here

20:59 got areas that are exposed during low of lake level dry periods, you're

21:09 have a lot of evaporates here, of apple rights and you may have

21:14 nuclear hated evaporates as well. And may have some sediment come celeste classic

21:21 coming in as well. But an lot of it is going to be

21:28 precipitated, dissolve solids. Well, legs are typically associated with internal

21:38 Okay. And if you look at those areas are there Australia, the

21:49 , basically, they tend to be desert areas. Okay. The Gobi

21:58 less so with the pompous sitting But And the reason for that is

22:04 you want to establish a through going , you're gonna have to fill all

22:08 holes. It's kind of a fill spill. The next fill and spill

22:13 and spill. Giovanni reached the Zeke if there's not enough rain. You

22:19 feel that first bill. And so drainages are typically associated with arid

22:27 They're also associated with areas of a amount of block faulting. So the

22:35 way too segment. The Grandage basin to break it up into fault horst

22:46 in fact we saw that with the grande route. Rio grande river was

22:54 the headwaters of the river and the partition by block faulting during basin

23:00 During the Miocene. It wasn't until those robins were filled and spill that

23:06 have the reintegration of the Rio grande . So if you're looking in south

23:12 , um you don't see much until those block faulted bases had filled in

23:21 one of the reasons they filled vaulting and so I couldn't maintain the relief

23:28 eventually the Senate filled it. So eventually do see the influx of sediment

23:33 into Rio grande health after those closed had filled. Now let's go back

23:43 look at stratification for a second. we look at solar radiation, we

23:50 to vote example going into the april summit. If that's very uh 10

23:58 , it's probably, oh, the part of the this is, I'm

24:11 quite sure um is well mixed, means it's warm, but it's uniformly

24:21 to the bottom. Once we get that fixing zone, you see a

24:30 in temperature coincided with a decrease in decrease in thermal solar, But it

24:39 levels out in about 4°C. And the for that is that as ISIS begins

24:47 water is beginning to freeze, it to form linked, solicit silica tetra

24:56 hexagons that have a little more space therefore less density. So the most

25:04 packing of water is occurs not at it freezes, but when it's about

25:10 freeze. And so up until that the silicon tector he drew are getting

25:19 together, more dense and then At 4°C. We have our density max and

25:26 like that problem. Yeah. Now thermal type is a measure of temperature

25:36 with them. We can also talk the picnic client which is a measure

25:42 density variations in depth. If you a fish, you might be more

25:50 in the thermal Kline. But if are hydraulic, they're more interesting than

25:56 , because the low density cap is keeps this floating and therefore these potentially

26:04 from the high density lower zone. unless you've got a way of breaking

26:12 that technically by all of this water gonna stay up here and more specifically

26:21 of this oxygen is gonna stay at . Yes, unless we can break

26:28 up. Break up the stratification, gonna have an an arctic zone down

26:36 . So here we have empty Let me on late. That's a

26:47 Mhm. I tend to think about on that really just a transition.

26:58 here's a thumb applying well, lots of that experience poorly mixed.

27:08 , one of the ways of breaking that Nixon later. He's not waiting

27:16 when you have wind blowing across the of water. If I want that

27:21 be late, it could be a . The water accent piles up.

27:28 it filed up? It forces a . So what we see here is

27:37 being piled up a down welling which turn forces and upward. Now nutrient

27:47 water, nutrient rich because they haven't uh oxidized are coming to the surface

27:56 oxygen rich waters are coming down so can have minimal medicine at least the

28:08 . And this probably holds in oceans well. Now in addition to driving

28:16 , there's a lot of features above things that we get along the margin

28:23 large legs and his legs that have big fetch. Uh that we would

28:28 in any marine setting. We get , we get barrier islands fits programming

28:37 . So there's all sorts of Yeah. Um Here's an example um

28:46 very wrong awake. Oh the other I want to point out remember when

28:59 said there's a down dwelling on the side is being that download can not

29:09 bring oxygen to deeper water, it actually bring settle in the deeper

29:15 So what we get are some of sediment drips. Yeah, bringing creating

29:23 settlement down into the deep part. is not a turbidity current. The

29:29 current here, here we're But here are. Whereas here they are.

29:42 induced. So in a strata pot an idealized lake fill. No change

30:01 the water surface. I mean If it's for getting internet in some

30:15 Oscar pods because an offender. Suddenly could be these sediment drifts that could

30:25 the high protected source above it. go through self the same and this

30:36 predominantly mimics pieces. A lot of we've got this. So we get

30:50 and this could be waving to short could be cooperating dealt well. They're

30:56 currently set if it's not a strategy . I think that is to say

31:06 there is uh mixing for whatever months down here are gonna be

31:17 It's the there will be a sediment as we go upwards. We're gonna

31:27 to see on the why here we , what do you think? Primary

31:46 . Structure five. Hey, this the way is exactly the same thing

31:56 happens in green sex going on a scale. Into a certain different secrets

32:04 . Yeah. And in many cases the electrical picture of the gamma ray

32:26 has to be sensitive to the relative of players and and so we use

32:33 as kind of a third great So when you see this uh rise

32:40 one of the hot uh flood saying that that's a whole another area of

32:52 . Well, log interpretation that I'm know, kind of ignore except for

32:57 I just said. Oops. so we've got the sense of stratified

33:06 non stratified. Now let's look at and let's think about source for specifically

33:20 relative size of the catchment areas compared the size of the face and as

33:31 increase the relative sides of relative, gonna get more more water coming

33:42 So you'd expect perennial place like always be with this large, but you

33:55 also the climate is gonna and does good. So with this climatic

34:07 we basically go from, well dr , large catchment basin turn so larger

34:25 this field here, that's here. you got this perennial link, it's

34:33 open lake. Um but you're gonna you get more and more for any

34:41 uh geometry as you get drier and and ephemeral lakes that eventually gone in

34:57 solitary. So it begins to give a sense of how drainage and lake

35:09 and climate affect the type of length we're getting. So let's take a

35:16 lake that might actually evolving from flood say what are the types of

35:24 Yes, we would expect. alluvial fans are gonna be in all

35:30 the things that we're talking about But then as we come into here

35:36 but flats, maybe a sand dudes, rich and probably error.

35:45 gonna break it. So that might a kind of a typical hold

35:57 All his leg supplier said this is from your textbook, this is more

36:05 the line of what dr Davis might been talking about. But again,

36:12 got this Bahana sand flat with without saline lake and okay, such as

36:29 see their help with the alluvial fans the fan plants to the mudflats and

36:40 so in as preserved, we're gonna this inter bedded kind of muddy flats

36:50 the back lines. That's the first . This is gonna be where we're

36:54 be looking for bad and neither are of the sequences you might get on

37:02 lake margin in early on preserved in deepest parts are gonna be a permanent

37:15 saline waters. Well, now, the water begins to drop as we

37:22 from the open to assistance, we from a perennial to a criminal

37:30 We go into a permanent decisional. . When it was permanent and particularly

37:43 it's stratified, here's our oil change here's our mud stuff. So this

37:50 going to be that base of the and he's gonna be. But on

38:09 no beach, obviously that was big . Got themselves. So you just

38:16 some, we're looking at if that here in the center as well as

38:31 the what one of the things that still grapple with is the fact that

38:41 can get a lot of evaporating deposition the center plate because it's hyper selene

38:50 we're getting crystal growth on the the crystal here or often growing within

39:05 muddy matrix. And so they're gonna logical if it was sometimes called chicken

39:11 structure. So this would be the for permanent non stratified assault. Let's

39:23 an example of where that may have out. This is in Argentina and

39:29 is uh, an oil field in restaurant. It's got the vaulted

39:40 Alluvial fans reading into the company Right here the light, lighter

39:54 lighter color. Come right here, flows. Grady, I'm sorry.

40:03 dairy flows of the orange. These taylor's coats. Whoops. No,

40:17 about? I'll be there. We a tactical for one. Okay.

41:21 need to get back to screen too I can't, I can see

41:37 but I can't, we'll always have . Okay, you're trying. I'm

41:54 need your help again. Sorry, can't get back to this that and

42:17 clicked that but I don't see click different. That's what I want to

42:25 to. I can't forget to here we go. Don't know what

42:45 did that this them stuffed shirt. , okay. Where I want

43:08 Okay, Alright, okay. We're where we were, we got this

43:17 in the no mid to distal alluvial . The fluid. Then we go

43:34 , let's look a little more specifically what's going on. Okay,

43:53 We had periods of relatively low standings brought with a lot of reworking of

44:08 of building. It was eric it a lot of evaporation getting bailey

44:23 strict ID. Like with significant So that was the evaporative period will

44:33 a lot of evaporates forming at the drum, analyze ships in the hairline

44:42 level rose when it got wet. so the lake became less sali less

44:56 and it began to rework those dudes has extensive do feel during the

45:08 No, Those sentiments will be only Dr. seven or positive as high

45:19 flow sedimentary gravity flows down into the water to overfly the embankments. It

45:29 time and time again. The evaporator . No doubt respected writes carbonates

45:54 Uh, so that intermediate zone right here, we lose it when we

46:09 too far away. I protected for lose it over here where we don't

46:21 the map lines. So this fluctuation open and closed or at least more

46:28 . And let's say leave uh, is giving us a significant opportunity for

46:38 pay zones. Now, when I about here is really the classification that

46:49 mainly use or is mainly used most . But let's begin with thinking about

46:57 long and still maybe another. Let's on this. Right, wow.

47:12 into in a series. Oops. , I'm just saying, okay,

47:33 exiting right here and of course it's do that for. So climate tectonics

47:48 determining how much is coming into the basin floor subsidence and still uplift affect

47:56 accommodation range, which is. So look at this. The rate of

48:07 coming in. Both water and sediment is a function. The large extent

48:22 the amount of precipitation. More water blowing into the city for precipitation over

48:34 yet. Oh more water percent. not any subsided what you're gonna get

48:47 . Really? Oh and by the , so the extremes this is

49:03 No matter what the wrote the accommodations it's gonna be old. There's a

49:11 of variation within here but that's the . Uh huh. Here though,

49:18 gonna happen as you increase the ratings science for concentrated water again you're gonna

49:29 from the river related because there's a of waters in these overfilled with his

49:39 over until then. Yeah if you to increase the accommodation brain but you

49:52 change him out with water instead of in. That's gonna become a balanced

50:00 and field. So you can talk being overbuilt. Yeah. Out under

50:18 . Let's see what those look. When you got increase accommodation brand tend

50:40 go from thin sick. So so at this here. Why is it

50:50 is the package here? Let's do here thinner than here because of the

50:59 in a combination left The last 7 10. So I had the thickness

51:13 the custom. Right okay so let's what is it characterizes overfilled with.

51:28 1st 1 overfilled lake is an open . Therefore love to stay stable

51:38 Well in fresh water in the if think of this as being a half

51:53 . We have the master ball over with alluvial fans going into now.

52:04 here we have belters as well but procreating and they may actually be in

52:15 typically hard associated with large. It's to make this connection. Exactly just

52:26 these can be larger like I mean built well and the appropriating as well

52:39 so as a result you tend to from grading para scenes with a lot

52:50 flu bulimic, anybody looked like this . And here's another example of a

53:06 open, right killed it. Now particular of the gods at all.

53:22 a good place to get some of , the petroleum characteristics. I'm just

53:28 kind of skip over it because it's but basically highest porosity and permeability and

53:36 overall resource associate are associated with these . Okay, okay. One of

53:43 word once started teaching some really important realized because I never looked at things

53:55 big plan, the profoundly just needs deeper portion of the thing and that's

54:02 your yet they cannot now balance bill open sometimes for Les, which means

54:22 gonna be variations from periods of time at least on the low relief side

54:30 going to get transgressions and regions we're going to get stable program. So

54:40 gonna have well showing of, we talk more about but basically as the

54:53 fan belts building cycles, input Um they're the best vertical permeability

55:14 But again, I'm gonna leave you look at these as you like.

55:21 field are close links. As a , it can be a lot of

55:35 and blood stones in punctuates a completely . You still have, we still

55:44 some code. Let's make it We might get some travel coming up

55:53 the hot springs, there's gonna be recharge and so we're gonna get a

56:02 of the vaporize and other characteristics. a clothesline. This is our imposing

56:16 it has the thickest death penalty in because approaching vibrates accommodation. Hey shot

56:27 best horizontal when but it's complex you can you can make this situation

56:40 here's an example. 1 2nd. you. Try. This is ray

56:52 . It's never completely inversion but it's fun. We get blood cracks,

56:59 mats information. You're back basically do high percent concentrations. If we look

57:15 this area here standard, just have better idea. Think she's tried of

57:20 of the shallow saline lake systems again the shower. Hey, and you

57:35 be an example under filled lakes. then this is I like this diary

57:47 it kind of give me a visual of thinking about the transition from overfilled

57:56 under filled with really overfilled. You get there should be solicit plastic

58:11 But as we get more into balanced classic sediments begin to drop out.

58:21 begin to take over and then evaporates there. So that rights are dominated

58:29 the under filled and mixed. You flu viel to evaporate rights and

58:38 You get predominantly classic physical sedimentary That would be the uh sedimentary structures

58:47 uh cross bedding. Okay, dominantly began to get biogenic structures associated with

59:00 carbonates and then chemically associated structures chemical with the of athletes stacking goes from

59:12 gradation to aggregation biodiversity high in the . The load of very water low

59:20 you build from freshwater to hyper So it's intuitive, but it's a

59:29 visual way of thinking about what's happening that lake goes from open,

59:35 overfilled two closed hyper saline under Okay, and again, I'll let

59:43 read this, but it's kind of summary of what I just said.

59:50 there's a lot of oil in different environments of the lake system. There's

60:01 lot of it is from streams, streams and greatest streams, alluvial

60:07 van deltas. So we're gonna see and we're gonna pretend like that doesn't

60:12 . Uh We're gonna look at these environments to see what are the reservoir

60:20 . And so one of the things recognizes when we're looking at the evolution

60:24 a base in Philly. Uh We're gonna look just at one type of

60:32 , those legs change with time, like the alluvial fans. We saw

60:37 with time. So it went from ville to overfill the balance to

60:42 And this is just for one of basics. So let's look at some

60:50 the lancastrian systems in terms of tectonic and basis. Or we can look

60:59 the east african rift system, which the way is, is a dead

61:06 for those early drastic to cretaceous rift in north and south America. So

61:16 you're interested in sub salt riffs, the analogy is at least in part

61:30 what is exposed in the northern midland there's no salt like the Newark basin

61:37 also in the east african rift we've got a big sad lake here

61:44 a lot of lakes running down So let's look at a typical lake

61:51 lake structure well and it turns out a series of half problems even though

62:00 think of it as being pulled Extension is not giving us nice,

62:06 roberts is giving us these alternating zones half province. Let's look at it

62:19 closely. There's a half Robin, a half Robin and there's a kind

62:27 a transfer zone connecting those to have in different directions. So we have

62:35 hinged margin and in there's a lot different words for this main fault

62:42 but it's our half brother. Now beginning to see where some of that

62:56 , those deltas come from because there's lot of drainage basin area available to

63:05 into the hinge, March, there's much drainage basin area to go into

63:10 escarpment, March. So that's where would expect your little Fan belt is

63:15 we saw the western side of the of California. Okay, this might

63:24 more like the eastern side of the of California, draining larger areas.

63:31 . Now, if we look at species within this lake, which is

63:42 pair of half Robbins, um one the things, I'll point out here

63:50 then I'll look a little more The second is that we've got deltas

63:59 in here and here. Little Fan aren't bringing much, we've got a

64:06 of classic mud here and then a blanket down here. So there's a

64:16 to sell axle trans gradation, this not mud in the middle and sand

64:23 the sides. In addition the sand the west side on the hinge margin

64:31 much wider than the sand on the or escarpment margin, which is much

64:41 because we've got more drainage area and bigger rivers coming in on the hinge

64:47 side. Now, if you look little more closely now we were looking

64:55 hinge margin over here, not only we getting rivers coming in that are

65:00 large, both axel and on the , but we're getting these sublet custom

65:09 and delta deposits are hyper picked delta . He was here just Fan tells

65:16 not much. Yeah, and this that russell. So the wind is

65:26 from south to north and therefore the deposit before the classic deposits are restricted

65:36 to the northern zone, much to sun. This is a family of

65:48 , the east african rift system that tremendous fluctuations in water level hundreds of

65:57 . So we actually have high low stands deposits. And we even

66:04 what's kind of analogous to a uh, a continental slope. Dark

66:10 shell. Right? And we have size canyons and sublet custom fans.

66:20 . And then up here, I deltas, We have up to 300

66:32 uh lake level base level change. uh, in 12,000 years.

66:42 now let's say, yeah, About years 150 In about a 4000

66:53 That's a lot of change. It's a lot of water that's lost 97%

67:02 in water volume And 89% reduction in surface over 150,000 years. Yeah,

67:13 here's that same module. But this the accommodation. So the rift shoulders

67:19 the block vaulted area. I'm the block fault margin, The flexible

67:26 is the shoulder. So this is half roll and you can see how

67:33 changes as we go down with robert's . And and that's basically what we're

67:44 here. And that's basically what we talking about with the open overfilled versus

67:53 field. Okay, so this is model that we can visualize in cross

68:00 and here's a model, we can for that same half Robin in Matthew

68:08 have the active margin where the main is with a series of small Olivia

68:21 and fan deltas depending on whether or the lake has been filled on the

68:31 side. We've got larger alluvial fans in some cases deltas. And then

68:45 have an axial river that typically is in well parallel to the troll.

68:56 let's look at some examples. Let's first of all in a case where

69:02 the lake hasn't hasn't been filled So here's a case what we got

69:09 symmetrical Robin with Fan deltas coming in into the lake and braid deltas coming

69:19 here again from the lake, it's these have a larger drainage area.

69:24 is that lower areas, it's not steep, still fall boundaries, it

69:31 out, but it's not as And then we have some deeper water

69:36 going on here. Sobre deltas where less subsides. Fan deltas where it's

69:42 and smaller granny jerry here we have deltas, we have the main fault

69:52 rather fans. They were fan deltas just one leg compared to more stream

70:02 deltas, larger and more water related there's a larger drainage area.

70:11 it's a half dealt. Yes. you can see the difference in the

70:19 area and therefore the difference in the of the alluvial fans and the difference

70:28 the type of sediment transport larger drainage . Higher, more precipitation. more

70:36 related stream flood stream, um, relief a small area. Your brain

70:43 . Okay. Uh, here's a where we've got an axle river coming

70:49 forming a rather large delta that's filling this lake. That would be analogous

70:55 this longitudinal river. Here here we the river building in the fault bounded

71:10 alluvial fans, merging with this longitudinal and this was a lake until it

71:26 up the same pattern. And one the nicest examples is a devonian and

71:36 shows that trans intentional half throttle Up 25,000 ft of cm of set a

71:47 of subsidence and on the flanks on flank, we have stream flow dominated

71:55 and another flank other side. We the brief flow dominated fans. And

72:03 you look at the math view, got debris flow plans, larger stream

72:12 plans in an axial delta coming filling the lake in particular cross

72:22 We have these smaller, smaller debris fans in these larger streams of

72:31 Again, we're looking at them here then what this is this is the

72:39 filling up with this actual river actually a graded stream. Okay,

72:46 here's that like custom fan delta, coming down the axis and here are

72:54 little fan deltas coming in from the . Mhm. And we talked about

73:02 before. Van delta, braid Ban delta, braid delta, Van

73:13 , Xray delta. Here we go , steep, steep here. We

73:24 have a distributive alluvial system. It's a large system that we're actually getting

73:30 splitting up. But again, the of these asymmetrical robins ban raid or

73:52 , 3 15. Uh you wanna now or try to finish up and

73:58 it over. Hey, okay, . Well it'd be nice if we

74:06 just finish it and leave early. . Um, Gilbert type deltas are

74:13 assumed to be the norm for the deltas and the Gilbert type delta is

74:20 described as one that's got Top steep four sets, shallow bottom

74:30 just like this. And the reason the, or the assumption that these

74:40 what should form in deltas is because you have fresh water, alluvial deposits

74:52 and diverging into a fresh water you have what's called home a pick

74:58 floor. The density of the in water is the same relatively as the

75:08 water. Fresh water. Fresh So the argument is, you have

75:14 very rapid divergence. The flow lines rapid sedimentation rate and the deposition of

75:27 four cents might look like this. , and this is an example of

75:37 Gilbert type guilt. The problem is in a marine environment. So the

75:45 thing we have to acknowledge is that type deltas can occur in marine as

75:54 as the acoustic settings. They're not to the customer and they're not unique

76:02 or float. um that are well , very steep. A lot of

76:11 sands, massive gravels, a lot sedimentary uh defamation. Here's another case

76:20 marine deltas. Starting off is what shallow water deltas and gradually as the

76:33 deepens grading into Gilbert type deltas. what what Gilbert type delta is really

76:44 are delta's pro grading into deep relatively deep water without a lot of

76:54 . So you're depositing large force. into that system. It has almost

77:04 to do with the home a pick flow. And it's not at all

77:11 to lakes. In fact, many deltas are completely unrelated to Gilbert

77:21 Now I'm expanding on this because we read everywhere. This is the type

77:27 delta you get with lakes. it's the type of delta that you

77:31 in alluvial lakes that G. Gilbert described around Salt Lake City when

77:41 lake level was high and it was into a steep front. Yeah,

77:52 do see in this case it's lacosta Gilbert type deltas, um pulses of

78:01 grading transgression for grading transgression. In particular case, we're looking at sequences

78:12 to episodic thrusting. We talked earlier how alluvial fans. Systems could pro

78:20 and out by thrusting by tectonic lee allergenic site, they're all asleep.

78:28 , so this is one case um lake bonneville, it turns out where

78:35 Gilbert deltas were first discovered and they basically, the course reigned steep

78:47 Water deltas elsewhere. We got fine deltas that weren't Gilbert type. So

78:55 have taken these three or four examples it is multiplied like mushrooms.

79:04 Now the rest of what I'm going talk about, our case studies,

79:10 of chinese deltas. And then reservoir associate with those and I'm gonna talk

79:16 the Bohai basin, the Hunger The early in basin doesn't matter their

79:22 necessarily, but know that you can them if you wanted to. And

79:27 look at the early in basin first all, and this is a really

79:31 early publication by chang song Back 20 ago. And if you look at

79:39 cross sections, you see there are bunch of mainly half problems. This

79:44 typical of the structural setting of these bases. Okay, have problems.

79:52 so here's a a and interpreted seismic . We had alluvial fans raiding into

80:03 deltas. So we've got lake Now, then down here we're getting

80:10 lancastrian deltas are fans wrapped over here deltas. So we're seeing this transition

80:17 fan deltas on the steep flank to deltas on the less steep flank.

80:25 , if you look at the deposition within the early basis, the size

80:31 , field grade deltas and the Subway fans and hyper pectoral deposits here are

80:38 main residence, Louisville fans. Don't about. We've talked about those and

80:44 not reservoir, but they're restricted to early phases of that delta before it

80:53 a lake. And actually maybe at , the later phase where the lake

81:02 filled, that we would have alluvial bands grading into non lancastrian lake

81:13 . Fan deltas are occurring when those fans are now grading into a

81:20 The system is closed or at least the accommodation rate has increased. But

81:28 getting a lake water. We have delta front and then a floodplain.

81:41 delta front is where there's a lot reworking and therefore it has. The

81:48 for being a resident is that we something in here. It's also that

82:01 and we saw in the devonian where were looking at that axial lake coming

82:09 axial river, rather filling the lake the east. Now, here's what's

82:18 a fan delta for the hunger. , I'm not sure that it might

82:24 better called a braid delta. There's its transition. But this is a

82:30 fact. These are, these are and inter channel bars. Uh,

82:36 is a reminder that you will be an error if you just do a

82:42 strata, graphic correlation of sand You need to do a chrono

82:47 graphic correlation. Uh, here's another where this sand does not correlate with

82:55 one. Correlates down here. So have to think about what are the

83:02 that are giving you the the The pro grading timelines and therefore pro

83:12 sands. Anyway, so here are deltas and the reservoirs are mainly in

83:23 zone here in the fan delta That's the reworked area. Yeah.

83:29 those are gas reservoirs here. We've a fault here. Van Delta's here

83:39 great Delta's here raiding into a delta . There was a lake there

83:49 We've got Van Delta's adjacent to the margin, gray deltas to the southern

83:55 . Okay, that's what we're looking here in a different reservoir, except

84:02 , we're actually looking at the we see this pattern over and over

84:09 , the great deltas or some of better reservoir. Some of our best

84:13 were their finer grained, they're thick coarsening sequences probably when it was a

84:23 delta. This is an example of variation and permeability in ferocity of one

84:35 those delta lobes. So there's a of variation in here, which we

84:41 talk about later. Talk about deltas here we have not a great delta

84:49 a meandering flu viel delta. Uh again, both our river dominated

84:56 And so these would be the equivalent those stream flow to unconfined or two

85:10 river belters. Okay, and they're occur in the axis of the trough

85:18 on the lower gradient margin, non margin of the half Robbins.

85:25 eventually those fan deltas and those meandering great deltas coming in are going to

85:31 the lake. Okay, so the is gonna disappear. And what happens

85:38 this? It's all meandering river and fan. Yeah, we can have

85:49 stand and low stand deltas that can opened and closed, insane vertical

85:59 I stands tend to be wave Remember how much area was covered,

86:08 , uh to wind on the high of the lake Malawi. More

86:18 more of a wave dominated delta down , there's not much wave actions.

86:24 little more flu ville dominated. You have a lot of evaporates if you

86:30 to know where the best reservoirs Look for distributor very channels and mouth

86:38 in those delta and lacosta and delta . Okay, we'll skip that.

86:46 , another good place to look is incised valley field. Here's that incised

86:52 . Okay. And there were getting pretty well sorted, forced to find

86:58 stones and gravels. Now, what's these they're gonna be submarine sedimentary gravity

87:08 and slopes. Here's a cohesive debris . Here's a high density turban tight

87:19 here are thin bedded, lower density . Now there's we're gonna spend a

87:28 of time talking about these types of sedimentary gravity flows. We talked about

87:36 water, marine setups. Let me say here that we get the same

87:42 of sedimentary deposits in lakes as well the marine and dark. And we

87:50 the same transition from Deb writes the pick nights which are hyper picnic flows

87:56 I will find that a little better hide to low density turbo tights.

88:03 , so here are sandy debris flows muddy debris flow and here's a high

88:15 her body, the low density turbodyne this particular turbid Aight is serge like

88:28 this particularly turbid ite is classy Now, what we mean by that

88:35 search type turbo died is one that there's failure very instantly we get all

88:43 sediment put into suspension in one event then it spills out into the deep

88:50 of the base across a stable low interpreter is one that's being fed over

88:57 long period of time and that's due a river. I concentrated river sediments

89:03 into a basin for a long That's what I mean, a long

89:07 . We can have rivers in flood weeks, maybe months, but certainly

89:13 . And so that's gonna give us different pattern of deposits. Now,

89:23 actually showed this earlier and I said was an example of a relatively stable

89:30 grading para seats, but in it's not stable. It's kind of

89:37 up up. So there's a pro , all climate forms followed by an

89:46 platforms and procreation. Now, that to do with the rate of sediment

89:54 accumulation. That's pretty straightforward. But importantly, okay, when it's pro

90:02 , these deltas are right at the edge and they're slumping. And these

90:09 are giving you a series of slump and deeper fans when it's more

90:21 These are beginning to break into turbo channels in submarine fans. So we

90:32 bypassing the deltas to get into the water deposits with sand. Now,

90:45 the slumps, this is kind of we get this slump induced fan and

90:54 often elongated debris flows. Kind of like those debris flow lobes. We

91:02 on that debris flow dominated, uh fan. Now, they're associated with

91:11 steeper front here. This is an a pack, but it really consists

91:17 a series of overlapping lobes. and you can see in cross

91:29 this is one in brazil. There's delta, here's those individual sand lobes

91:40 grains uh too 30 m, 30 thick sandy loads got a potential

91:55 Here's another. Okay, um up 60 meetings of Sandy Lopes here are

92:07 of the slope deposits raiding into turbidity . Okay, in fact, that's

92:18 of what we're getting here as we from a sandy debris flow to muddy

92:23 flow to turbidity currents. Now, it's slumped, it's gonna be a

92:30 single event turbidity current. Okay, here are those Sandy Debra. It's

92:37 are permeability is up to um it millie darcy's uh yeah, or

92:46 it's not millie darcy darcy permeability is to 8 to 14%. I gotta

92:53 this, but permeability is high enough these are residents. When we look

93:00 in here, Here's permeability, ease up to two Darcy's averaged 200 million

93:09 for these sub custom fans associated with Debra writes here. Lower uh army

93:22 . Similar the lower process. I to double check this out here.

93:29 , here's a blood triggered system slump system, debris flow, high density

93:39 . Current policy, steady turbidity, debris flow. Oops. To search

93:47 density surge like turbidity current. The thing I want you to remember for

93:53 now is that these deposits can be our bridge and uh and laterally

94:06 But they vary let because what has is very deceptive. There is a

94:15 of that sedimentary gravity. Yeah. I did see tremendous crime today.

94:33 . Oh yes. Each of these have a characteristic sediment package.

94:45 I'm gonna defer talking about what those are and therefore how you distinguish.

94:52 I want you to recognize that there seven biological signatures for each of those

94:59 , even of a single event. can think of this almost as a

95:02 . She's man um of an So here we have coming in in

95:12 water and here we have flood generated to diets and there we have paint

95:27 generated turbo adults. Yeah. Here the slump generated uh sedimentary gravity flows

95:39 you mainly Sandy device. And here the flood triggered sedimentary gravity fluids.

95:47 um Well fine. Now these hybrid are basically flood generated, 70 friends

96:09 form in you can have this So coming in and they're staying high

96:21 a long period of time. So is basically the duration for yeah take

96:31 focus and as a result you've got and and erosion at various times as

96:43 information that material is accumulating. So got a variety of vertical sequences.

96:54 you don't have is that plastic bomb sequence that we think of turbulence finding

97:04 massive parallel Ripley. And again um it's that vertical variability that is characteristic

97:17 I predict whether it's or something or . Custom, vertical, very building

97:24 size, anti sedimentary structure and thinks can be a lot thicker and many

97:31 they are more long lived. Um Here's just an example of some

97:37 the variation you might get. Uh player later. Um here we have

97:54 upwards the packets but at different scales have the this variability. Yeah.

98:08 similar story here. The take home the variation and the origin here,

98:21 not a hypertechnical, it's a failure time we generate a degree flow going

98:32 . But the density of the turbidity is getting less and less in part

98:37 it's incorporating water as it flows down because it's a signal and then we

98:45 the capacity development finding those same very . Get um getting towards the end

98:58 . Uh This is the north Auckland in the south atlantic isn't that Robin

99:08 is uh, this if we look that as a half problem, what

99:20 we see side? You see little and a lot of these subs custom

99:32 . These are the major residents and inside sally. These are just kind

99:45 some sketches and some of the vertical here are those fans that's time slice

99:55 they have broken up in folks if this looks very similar to when we

100:03 in marine. There's a lot of and basically what type uh det

100:23 These are the, so when we're into the deeper water causes, we've

100:35 two things either have sand coming My slumps and surge is one or

100:44 setting out of suspension. So the consists of fine grained material. I

100:54 much in some cases the uh, it's shallow it may be blood

101:06 stones will bring money, but below critical death using we get the six

101:18 that are typically laminated, high organic . Um, Nick writes so and

101:32 missing. Well clued you an, ignoring all of those sand um,

101:40 gravel tons. This is what surrounded forces your brain deposits. And one

101:48 the things we recognize the country particularly those portions of them that are

101:54 in an anoxic conditions is they are laminate. Mm If you look at

102:03 lamination, they are typically, let's often patient place Number one, you're

102:14 there. The annual barbs that we of the blood customers deposits. Now

102:21 other ways of getting lamination. Um not gonna get into as much as

102:27 the text. You can look at later, you can peruse and but

102:36 vary from where there's something controlling them a kind of a regular basis like

102:45 , weather conditions to irregular events, a volcanic talk or something else.

102:53 , when you look at those look at those deep places, fish

103:05 began to look at herself. We one of 48 analysis that if you

103:13 the east lamination is a year, is pretty good. It's then you

103:21 figure out that you have certain peaks varied a certain find italy. There's

103:29 20 years. So. Oh I mean 20,000 a. 40,000 140

103:45 . Those are basically climatically controlled. , have you heard of like

103:56 Okay, okay. A cycle is a cycle of variations in incoming solar

104:08 based on long term astronomical changes in position of the earth and sun.

104:17 so uh an 18 year cycle is common. We can see that in

104:23 title process. But the 120 year is the cycle that seems to to

104:31 glacial integration. And we have finer and longer cycles. So a lot

104:39 our twice the scene climatic variation is by along these cycles. And a

104:47 of the cyclist city in our sedimentary is driven by that as well.

104:56 , we had these red lights down very small. Here they are,

105:06 getting larger and larger cycle that basically annual, longer term dynamic cycles in

105:18 cycles. Our technology. So we a combination of tectonic automatic control on

105:30 cyclist city, both the alluvial fans customers policies. Let's try that.

105:40 this is one. So this is this. It's And we're looking at

105:55 delta. All of your fans. . Bringing up into um public

106:08 fans ready back in. So a Mhm. And a cross section that

106:27 like this. Here's a great diligence the way, you know, lower

106:39 relief, lower rates of subsided that a problem. Here's our against the

106:59 we got shallow water deposits here overline flu beginning of the plan to transition

107:08 shallow delta. And they're going to water. We begin to see the

107:20 things is greater than the settlement supplies paper people beginning having great. This

107:32 more of a um overfilled setting. in notice we've got these deeper water

107:43 packets that are the simpler custard fans summit size balance. We can also

107:55 of axial center sources coming in here's our it's like and that's pretty

108:13 . Uh You won't say it but state we're beginning to say that

108:21 in in the chinese uh Custom systems least all over china. And actually

108:29 different tectonic settings? We're getting similar of the customer based film? Here's

108:39 one that's predominantly shallow to the function . So it's more of a balance

108:47 close this balance of 100. But ray delta shell. So what we

109:03 way we had this vertical transition from D. So here is that cross

109:20 be shallow. So this is how cross section might look a delta.

109:37 when we look at this, that's of what we're beginning to see.

109:49 this is a model that suggest that a half problem. And as early

110:01 it's a shadow room filled. That accommodation space increasing. Now that's filling

110:19 , delayed is actually even filled. still we have a border fall that's

110:26 the center. At some point we post riff for the sediment expands over

110:32 while. In other words, the have subsided by thermal subsidence and erosion

110:42 then there's no more base and Okay. And uh that's sometimes called

110:52 the longhorn model because it's got Okay. But we see it.

111:03 I mean that's typical. And so is just kind of a discussion of

111:08 style and the problem with this cross is something missing. What is missing

111:23 this graph section that I've shown you Many other cross sections. There's a

111:37 deposition system or systems that aren't shown . What are they? We got

111:52 like delta food. Mhm. Is nothing else that we talked about particularly

112:03 the margins with the face. She's at times too. The please tell

112:24 no thank you. So if not is missing in that space, she's

112:33 that just kind of describe crossing from in custody. What? I'm

112:52 Yeah, challenge. But there are shells. So the first thing is

113:05 is all the sudden stuff. The absolutely. We would expect to see

113:15 stand bodies in here. Now you argue maybe scale, but what's

113:25 All businesses, all the alluvial all the fan belt that are coming

113:33 from the flat. This delta here maybe coming from the actual plane where

113:47 filling up the whole valley. But was, and also it shows

114:01 I want to make this stops right . So, uh, this is

114:14 just here, it doesn't show the , but here's the filling. Remember

114:22 we had the, those axle deltas side delta is just completely filling the

114:34 . So I'm gonna take it. , I'm gonna have a question on

114:39 exam, we're read something like draw a cross section of a half Robin

114:56 you go from early flu viel through custom to a real system including syn

115:09 and post rift geologist. Okay, that's gonna be kind of a

115:15 this diagram, this diagram, that plus maybe some details. So you

115:24 to think about that first of And then I'm gonna also ask you

115:27 also draw the face. She's tracked a typical half Robin where there is

115:42 significant portion of it still having a . Okay. So you might think

115:49 it as someplace along will someplace along . Yes, or along here draw

116:04 the map view of the deposition system there we go. He got a

116:10 of sitting there. They don't get . Okay, so work with

116:18 And the last thing I would just that you know these these changes from

116:23 , maybe deep to shallow alluvial um They reflect in part long term

116:31 in the rate of sub science. the deep lakes typically are where the

116:38 rages uh the greatest and and as turns out um there for example

116:49 Alright, the but it turns out you're looking for source law, they

117:02 with those periods of baptist sons. bars are actually subsides rates. So

117:15 wider that bar the greater the substantially intervals of source rock formation are shown

117:37 . Okay, those deep lakes, source rocks are being to us and

117:48 in addition uh they are probably the where we have the longest lived and

117:58 and toxic deposits, the dark shapes ships. Yeah. So in

118:10 this is a good article to read the customer unconventional resources, no permeability

118:19 probably horizontal drilling or fracking. Uh gonna let you read this, but

118:29 of the things to point out is the custom deposits can be quite deep

118:40 of Lake Malawi 6000 ft of Uh, and again, you can

118:51 this. Okay, this lower Permian here. This is a good summary

119:02 why this particular lake system, as hydrocarbon potential. And this last

119:11 is to remind you that those deep rich, the customer deposits have to

119:27 expelled and then you have to get to a sandy reservoir. So they're

119:32 be mainly coming up false. So gonna come up the fault and then

119:38 distributed in this area here. you're looking at the migration as well

119:43 the source of industrial ones. All right. Uh, that's all

119:50 can talk about because I'm talked So I'm going to I suggest we

119:58 reporting better than

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