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GEOL6380 Sequence Stratigraphy - Day6 AM 05-07-2022
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00:00 mhm. I might put all these . This is more Exactly. And
00:16 field trip type. Lot of But mm. Anyway, so I
00:40 talked talked talked a little about another system that Farron sandstone in Utah and
00:49 is uh this is your outcrop example you're playing around with. So we'll
00:55 some correlations that might look similar. there's a lot of controversy about what
01:05 ah what causes sea level change. the cretaceous, the cretaceous is generally
01:15 to be a greenhouse. Some people it a an ultra greenhouse, so
01:20 one of the warmer times in earth , sea level was much higher than
01:24 is today. And yet there's still of high frequency sea level changes.
01:30 question is what controls that. So miller, who's at Rutgers University has
01:37 that ephemeral ice sheets and antarctic could caused sea level changes. If you
01:42 at the right hand diagram here, shows there's Antarctica at the top,
01:47 of course now is completely glaciation and go further back in time. You
01:51 the ice sheets get smaller and smaller million years ago and smaller. And
01:57 here we are, about 90 million , which is the mediterranean, which
02:01 the time period that I've been And he suggests that 15 to 25
02:07 sea level falls. So plus -30-50 of sea level would be compatible with
02:13 growth decay of ephemeral antarctic ice Is there any evidence for these ice
02:20 ? Well, Antarctica's right now is covered by ice that's probably the least
02:24 of all the continents. So the answer is, you don't really
02:30 uh, since militants work, there's some other hypotheses for controls on
02:37 use static sea level change. We're to put aside tectonics, you
02:41 that when oceans grow and when oceans , young, hot oceanic crust is
02:48 a little bit higher in the stratosphere displaces that water onto the continents.
02:54 so continent, sea level does rise fall Over 10s to hundreds of millions
02:59 years as a result of what we tectonic used to see, which is
03:04 to rates and magnitudes of sea floor and whether or not there's a lot
03:09 young oceanic crust, but those kind changes probably occur at timescales that are
03:15 slow. And what I'll show you is some, some of the evidence
03:20 much higher frequency sea level change in cretaceous. And you've already seen some
03:24 these examples and sort of here and , but we'll focus on this a
03:28 bit. The other interesting thing that's on is that the, when we
03:37 about Exxon trying to develop a use global sea level curve. I think
03:44 idea was that this would actually almost the geological timescale. The idea is
03:49 sea level is changing faster than And so if you can actually nail
03:54 the timing and patterns of high frequency driven you static change that that gives
04:01 even high resolution As two time zones as stages and uh and periods and
04:09 smaller units versus using traditional bios photography the conventional geological timescale that's developing into
04:17 science of astro chronology, which means the geological record on the basis of
04:23 of these molecular astro astronomical orbital And if you recall when I talked
04:29 the origin and frequency of orbital I mentioned that there were there were
04:36 , and 400,000 year cycles and that's rapid. Okay, auto genic process
04:41 as switching of big delta lobes, the Mississippi occurs over frequencies of maybe
04:46 couple of 1000 years. Small deltas switch even faster. But once we
04:51 into sort of 20 and 100,000 years were sort of into things that are
04:55 what we call allergenic or Alice. click were driven by processes that are
05:01 to the sedimentary basin. Mhm. , in terms of of of used
05:08 see which again means global sea level the greenhouse glaciers are sort of the
05:13 obvious way to take water out of ocean and stick it on the continent
05:17 call sea levels dropped. Okay. , there are other effects. There
05:21 what are called hysteric effects which is when sea water is warmer, it
05:26 a little bit and when seawater is contracts a little bit. So a
05:30 temperature change. The oceans can cause sea level change of about a few
05:35 . Okay, now, down Miller said, well, 15 m
05:39 sea level fall, that will be by 50 m of sea level
05:43 When the glaciers melt, that means could have plus and minus 30 m
05:46 sea level change or zero suitable uh gets taken out of the ocean is
05:52 the continent's withdraws by 15 m that melts and comes back up again
05:57 so so and so so and so . Um hysteric effects sort of plus
06:03 minus maybe five m. So you've 15 m. It can't be stereo
06:07 . The other hypothesis that's been around maybe maybe a decade is the idea
06:12 aquifers, that is groundwater changes can you static sea level changes. And
06:19 idea is that if you get more stored in aquifers, then sea levels
06:23 drop. And if you get less stored in aquifers aquifers than see that
06:27 can rise. Now, if you about that, you know,
06:33 when the earth is dry, you expect less water on land and more
06:36 the oceans. So dry periods might correlated with, with sea level rises
06:41 wet periods might correlate with sea level . Right? And you know,
06:46 then we tend to think, wet periods, warmer, warmer,
06:49 , high sea level, cold and , low sea level. So that's
06:53 of a that's kind of the opposite what you might expect with aquifer used
06:56 see. Um So we've been thinking this activity used to the idea The
07:02 says that if all of the actress the world simultaneously filled and drained,
07:06 could get a c double change up 40 m. However, putting ice
07:13 a content. Just one thing because content gets colder, but you
07:18 with climate, you know, it be warm in one continent dry and
07:22 , it's not clear to me at why aquifers would simultaneously rise and fall
07:27 the same time. You got different and different hemispheres. So my feeling
07:32 it would be harder to get synchronous rises and falls globally versus uh growth
07:39 decay of ice sheets. So although theoretical limit of aquifer used to see
07:44 40 m, Other people said it's not more more than 5-10 m.
07:50 the theory of adequate profusely is still much a theory. Anyway. The
07:58 thing is Matthew's back and I think we did some of the early work
08:04 on global temperature change suggested that the was completely ice free in the mid
08:11 . So there is that sort of out there that there was no
08:14 No, I see no significant icing planet earth in the mid cretaceous and
08:19 course that then requires you to okay, so if there's no
08:23 How do you get these high frequency Europe? See dollar changes. It's
08:27 gonna be aquifer used to see or effects. But as I've talked
08:32 those are probably probably just not big for the magnitude of changes that we
08:37 in the in the rock record. . Now, another thing that that
08:44 worth considering is that in a passive on the bottom got a hinge
08:51 Okay. And general subsidence is greater the basin. And the hinge line
08:55 moving very much. There's no real to lift that hinge line up.
08:59 in passive margins, it's very easy subside the basin which can cause a
09:03 sea level rise. But at a marketing by definition is passive but there's
09:10 way to lift that lift the sphere . So as a consequence, it's
09:13 difficult to produce a sea level fall a passive margin unless you drop sea
09:20 . That makes sense. You you can you can cause a relative
09:23 level rise by lifting the land Right? But then that that requires
09:27 tectonic lee active basin. So, I think some people protecting academics don't
09:33 is one of the reasons why. did all of their mapping of global
09:37 to see on passive margins is because said they're not tectonic lee active.
09:42 can't lift up. So we see from big sea level drops a couple
09:46 m of sea level drop. There's way you can lift a passive margin
09:49 by 100 m. That would mean a it's a tectonic Lee active
09:53 which it isn't by definition, it's passive margin. Now the problem is
09:58 lot of the, you know, that was sort of the story of
10:01 seismic photography in the development, the sea level curves that came from analysis
10:06 seismic data that Exxon had around the . But I'm just reiterating some of
10:12 lectures I gave I guess last Now john Van Wagner got in the
10:18 and was influenced very much by truck who you work with an Exxon and
10:24 worked on the gallops sandstone in New , which I've done a lot of
10:27 on mentored Van Wagner and got Van said, wait a minute, why
10:32 we take these seismic concepts and apply using well, logs and outcrops.
10:38 of course he was an ep arco production research company and you know,
10:42 being the size of the company. I said sure we'd like you to
10:45 see whether or not you can apply secret strata graphic concepts to more geological
10:50 and what better place to test that liquidations interior seaway. We got all
10:54 beautiful rocks. Right? The problem course is that foreland basins don't work
10:58 same as passive margins, they subside to where the load is. Okay
11:05 area here. The hinge line can up and lift. So unlike a
11:09 margin in a fallen basin, which an active margin, you can get
11:13 . Also, if you erode the away, that decreases the ice static
11:18 and the basement can lift up So foreland basins can kind of yo
11:21 up and down. Gabe. The , of course, is how fast
11:25 happens. And I've talked about the modelers and I mean, Gary carter
11:29 to say, oh, you if you removed a single grain of
11:32 that removes the load and the little will will respond by lifting up.
11:37 a grain of sand isn't much So the little sphere will lift up
11:40 about a 10th of a grain of . So, you know, you
11:43 to remove a lot of load to significant uplift. Right? So when
11:47 see sequence boundary and fallen basins, evidence of sea level drops and valley
11:52 . You have to you have to the question, okay, could could
11:56 of that sea level fall be the of lifting the basin up? Because
12:00 basins could yo yo up and Right. And so, you
12:03 I thought quite carefully about. so what's the rate of which foreland
12:07 subside and lift up? You and how much of the tectonic component
12:12 we ignore or extract when we're trying extract sea level records from foreign
12:18 That's a that's a little bit of of again, this, this is
12:21 , you know, we reviewed a bit about the tectonics of the sequence
12:24 of non marine basins and foreland basins the class in the class.
12:29 So this sort of reviews and, builds on those concepts, but the
12:33 being that a lot of high resolution photography has been done in foreland
12:38 but they of course have a, a different accommodation and tectonic profile versus
12:44 margins. Okay, you've seen this before. So here we are in
12:50 cretaceous interior seaway. The Tyrone Ian the time in which sea levels were
12:55 highest. There was massive sea floor as the atlantic was opening. The
13:00 atlantic little sphere was buoyed up in atmosphere, displacing water onto the
13:06 splitting north America in two. And was combined with periods of very high
13:11 global temperatures. So in general, very warm period with lots of uh
13:17 of high sea level, resulting in flooded continents. So here is a
13:24 cross section across the fallen basin and have a series of uh, we
13:29 the shale to the right, the shale in the more distant parts of
13:33 form of the seaway that becomes a . Those are things like the austin
13:37 here in texas. And of as we go towards the thrust
13:42 we start to start to get these of sandstone that intrude into the Mongo
13:47 and the sandstone that we're going to about this morning is the fare and
13:51 member, which is uh, sticks the tongue into the mongo
13:56 It over lies the shell and it's land by the blue gate shale and
14:01 passes ultimately into conglomerate. Ick It's a middle tyranny in the late
14:10 , late Santoni in age and it's to be a member in terms of
14:14 , photography. It's considered to be member of the mango shale formation.
14:20 word formation is sometimes not used, it can be confusing and again,
14:24 to go back to lecture to, think it was, you know,
14:27 lot of jobs. So it's, the, it's the, you
14:30 it's the magic of shell. It's Austin chalk, you gotta wait a
14:34 . Is that a formation or is is a group? Is it a
14:37 ? You know, and you get little bit losses to like wait a
14:39 . What, what, what, in the hierarchy is this? Is
14:43 myth a strata graphic, you we're talking about? Okay,
14:47 but the macro shell is indeed a and the Faron sandstone is indeed a
14:54 . My opinion should be elevated to formation, but I've never done
15:00 So the fair and sound stone is exposed in central Utah kind of
15:09 the san rafael swell and Call her in the 70s to find it to
15:15 a series of wedges in the Uh, there is the last,
15:20 he called the last Chance Delta that's bit younger. That's exposed, sort
15:25 from kind of around the town of and pinches out before you get to
15:30 . There's a delta that comes from north and south called the vernal
15:35 And then there's this delta that's exposed the Notam Road and around Hank's ville
15:42 that's referred that's referred to as the Delta. These are informal names.
15:47 they're smaller scale features the members. have to get one of these
15:50 I'm going to, I'm going to the note and dealt the last chance
15:53 out as members and elevate the fair a formation, but I haven't done
15:58 yet anyway. In general, the builds in general to the east and
16:05 northeast. So the last chance delta are essentially a dip section. Whereas
16:11 note, um, delta is sort a horseshoe comes down and then it
16:15 of goes east. So it's got much more sort of oval shaped
16:21 So it, it intersects the formation various angles. Jim Garrison attempt to
16:27 of put the, that the Um, and last chance in vernal
16:31 . I don't have the vernal is here. Uh, you may not
16:35 this, but yesterday I showed you of the john Henry member over land
16:41 the, that the uh, what hell's the name of the sandstone tarantula
16:47 ? This is, this was keith PhD work. The last chance is
16:52 little bit younger. The noted was older delta general. The note,
16:56 looks like it might be sort of third order fall of sea level
17:01 The last chance is a bit of back step. Uh, so at
17:04 sort of third order scale, remember have, we have first order to
17:07 all the changes. Those are the sort of wilson cycles that we have
17:11 order changes. Third order of the strata graphic cycles and the 4th and
17:15 order in general, correlate to use to probably glacier you static cycles.
17:21 these members might correlate roughly with kind third order cycles. That third,
17:27 3rd motorcycles that may have a quasi component. And uh, we do
17:35 some dates associated with these, which us to think about, you
17:39 because we have a pretty good bye graphic framework and we've got bentonite throughout
17:44 units that we've now gone back and dating on. We do have a
17:48 good idea of the amount of time with each of these delta systems and
17:53 relatively short lived, The known adult deposited in about 750,000 years. And
18:01 last chance deposited about a million which gives you a feel for the
18:06 timing of the duration of the deposition these units. So this is work
18:13 by Jim Garrison and his former wife the time, koko Vandenberg. She
18:21 to work at Exxon mobil. He at mobile and they both quit and
18:26 moved out to, he moved out emery Utah and got up every day
18:31 basically measured sections for several years and together this cross section of the last
18:35 delta each the black dots on the is one of his measured sections.
18:41 . And so if you recall, very last thing I showed yesterday was
18:49 Patterson's revised work on the book cliffs on hundreds of measures sections and Simon's
18:55 section looks not dissimilar to Jim's cross . So it sort of tells you
19:00 , you know, and you'll struggle this. You know, when when
19:02 look at your cross sections, they're look simpler than these because you have
19:07 data. Right? So we'll give an idea of how of how difficult
19:11 is to get all the details when have sparse data and how much you
19:15 in the subsurface world anyway. And is a simplified cross section of a
19:21 more detailed correlation panel that Jim Garrison together. But broadly speaking, he
19:27 of has a rim of shore faces deltas and yellow. Uh these correlate
19:35 worth with with a wedge of non faces that consists of floodplain, mostly
19:41 , mud stones and find sand stones green coals and black and then a
19:47 of channels, channel belts and sized showing the orange colors. This is
19:52 country and the Faron is mined for coal. In addition that coal produces
19:58 , there's coal bed methane as well gas. Gas fields associated with the
20:02 and sandstone. So it is it a it is rich in fossil
20:07 One thing it doesn't have is Okay, the other thing you may
20:11 , if you just look at it , what can you tell me about
20:17 distribution of the sizes of channels or belts in this cross section?
20:46 Brain freeze. Okay, I'm Right, right. But I think
21:21 think it does look like that cole kind of quite widespread. The channels
21:25 of in between the coals. It looks like the channels are kind
21:28 avoiding. It looks like you've either Kohli layers or channel areas. Sometimes
21:33 channels cut the calls out, they seem to be quite the levels of
21:37 cold, suggesting the channels are maybe graphically different in their origin from the
21:42 . Right. I'm going to I'm to question you on one thing you
21:47 pointed out. Well, you said about channels distantly versus in the sort
21:53 the green area. Right. McDonough that there were less channels distantly than
22:00 the green area. Do you agree that? I don't agree with
22:05 I don't that wider. So are channels here? Let's count it.
22:25 . 1, 34567, 8, , 10, 11, 12,
22:29 , 14, 15, 16, , 16, 21 27,
22:34 25, 26, 26 - 5 channels here. That's not fair.
22:44 . I think there's actually more chance about there smaller right now. Some
22:52 them are actually still on his Right? So now we're seeing evidence
22:56 single story channels with little amount amalgamation much bigger channels and sometimes,
23:03 you know, one of these channels here in the first shadow right
23:06 these distribution channels are just rivers. remember, I talked about the fact
23:12 in plastic wedges, you know, , you know, the channels get
23:16 as you go downstream because it become , right? And you may get
23:20 moisture channels landlord. So we are in general, I think it's very
23:25 . You see six solid channels on periphery of the wedge, bigger and
23:31 motivated challenges in the part of the , right? That's probably representing something
23:37 do with that trump versus distributor channels I talked about, right, whether
23:42 not an interpretation channel series a different . Do uh, they have been
23:48 so well for the last chance, my graduate students are well documented within
23:52 building, which has a lot of . So, you know, you
23:55 start to look at sort of the of channels of channels, which channel
24:00 versus these big things. It might valleys, you can sort of see
24:04 , you know, their values There's no valleys out here.
24:08 But they never got this far, sort of makes sense, Right?
24:11 , you know, some gumdrops, drops and the public's almost and
24:15 but the valley stopped before the low alone is deposited. Right? Like
24:20 saw in some of the other examples showed yesterday. Does that make
24:30 So here's an example of one of and Vandenberg's more detailed panels. The
24:38 lines represent their measured sections. And then these lines represent their
24:44 And you can see they've got multistory , uh local, sometimes they have
24:49 plugs. Right? So the, mud plugs kind of give you an
24:53 maybe what the channel is. They have a lot of lateral accretion.
24:57 you should have got the feeling for scale of a lateral accretion set.
25:01 then in some of these non marine , they have relatively small channels.
25:05 there's a channel belt that's basically one thick and the mud plug is almost
25:09 same thickness as the channel belt. that right down here and then we've
25:15 these single story, a single lateral set. So sometimes we've got single
25:20 channels and sometimes we have four or vertically stacked stories and jim used that
25:26 kind of distinguish units that he thought sequences or, you know, sequence
25:31 versus just single single channels. And can see, you know, sometimes
25:36 got to what looks like a multi sandstone, then you get a bunch
25:39 single story, the multi stories. there may be some cycling of single
25:44 multi story channels. So this is most language panel. This is the
25:52 panel. Again, you can see , we've got a a single channel
25:56 that's actually multistory. It's over lined a call. It's underlined by a
26:01 fill. And if you can trace channel to this mouth bar.
26:06 So the nice thing about the and you say, well that channel
26:09 that delta. So you can sort think about the scale of the delta
26:12 the channel that feeds it. So can link specific channels to a specific
26:18 that it feeds. There's a few in the last chance where you get
26:23 views through the channels. So this a vertical line that represents a strike
26:28 comes into and out of the page there's this nice channel in the middle
26:33 the outcrop has been named the kokopelli . And here's a close up of
26:38 geology of that channel. So the has this sort of shape.
26:50 and a lot of these channels have channel and what we call wings.
26:56 wings would be the crevasse splay, ? What you can see is that
26:59 channel is migrating in that direction. it's also lifting up just a little
27:03 , see that. And so what end up is with a channel belt
27:10 that's about the thickness of the Okay. Which is maybe 10
27:15 And the thickness of the channel belt maybe 12 or 13 m. So
27:19 maybe a few meters. The channel a little bit thicker than the channel
27:23 it's a grading just a little Okay, so that's an example of
27:27 channel. It's migrating and every flood lifting itself up a little bit.
27:32 , this is very common in river that when they flood, they built
27:36 levee up and the channel actually auto lift itself up. This is actually
27:42 it could be lifting up because it's the back water. So maybe a
27:45 bit of sea level is talking it's lifting up. But once the
27:48 becomes elevated or super elevated, you , if the top of the channel
27:53 a little bit at the top of water in the channel is higher than
27:56 old floodplain, then that channel will a temp propensity for Dulcich. So
28:02 jim didn't talk about the controls of . Many people have documented this process
28:07 a channel lifting itself up as it as a mechanism to cause and initiate
28:14 avulsion of a channel. This is good example of how a single story
28:18 migrates and can produce a slightly multistory certainly multilateral channel belt, multilateral because
28:26 the channel belt is significantly wider than channel that formed it multi story because
28:32 a little bit thicker than one story down. There's this thing called the
28:40 Line channel and that's, that's the Line channel there and that feeds that
28:49 bar. And there's been some debate to whether this is an incised valley
28:54 a distributor channel. Let's look at a little bit. So what's interesting
28:59 is what it looks like an So, you know, the air
29:02 is not vertically exaggerated, but you see what looks like a wing
29:08 Then it kind of cuts down, up and then it's got a wing
29:13 the other side. Okay, so what this thing looks like.
29:19 when I first visited this out this and the, I guess in the
29:24 90s, you know, we we just call this a distributor channel
29:28 moved on. Right. However, more I looked and I said,
29:31 it's kind of interesting. It's actually eight stories and stories 1-5 look like
29:39 incised 7, 8 looks like they're grading. So this looks like a
29:46 cut a fairly deep hole. Now a five m scale here. So
29:51 incision is about, I think it's 30 m. The actual thickness of
29:57 story is maybe about 5-6 m. , We're pretty close to the shore
30:03 , only five km, but this looks like it's sizing. So some
30:08 us think that this may be evidence this is some sort of incised
30:12 right? Having said that it's not wide. Like look at the lateral
30:15 here, this thing is migrating very . What is this thing?
30:24 Oh my goodness. I think I what it is. This is probably
30:30 backwater scour. Remember when I said the river that gets, when it
30:34 close to the shore line? And if the river is in
30:38 it digs down and cuts a little . I bet you dollars to
30:42 That's what that's what this thing And you know, when I realized
30:50 , so I've interpreted things in size . The other hypothesis is this
30:55 remember I talked about when the, the river's flood, the lower back
30:59 couldn't size a bit more deeply. when I figured that out. I
31:09 told you the story. Right, hmm. No, I figured out
31:21 , right now I'm serious. I went like, wait a minute.
31:26 been confused by this for 20 I bet that's a backwater scour Because
31:33 lower one is only 1.7 km of shorelines. That's, that's pretty
31:39 Okay. Anyway, so the interesting this this the the lack of the
31:46 of lateral migration tells what this thing . This thing was very short
31:49 Right? So it looks like it's a scarab that's that's eight stories
31:53 Now not all the stories are fully , but it's a short lived over
31:58 size system and a dust seemed to into a couple of power sequences
32:03 Okay, here is another small Faron and this is also quite close to
32:11 shore line. It cuts into three sequences. You can see the lateral
32:16 sets. Okay. And there's five stacked stories. The depth of the
32:23 is about 27 m. The depth channels is about six m. So
32:27 thing is cutting about three or four depths deep. But once again it's
32:32 narrow, it's only about 100 m . Right? So it's quite a
32:36 , probably relatively short lived system And so I stripped off all the
32:43 and then the blue represents the size the channel versus the largest scale scarab
32:49 it cut. Once again, I whether this thing possibly could be a
32:55 scour. I've got to think about some more. Anyway. Yeah.
33:01 I've worked on the, I started on the fair and First started looking
33:05 it when I joined Arco in And then uh I worked around it
33:12 I, when I worked for the of Economic Geology in 97, they
33:16 just finished a big project and when I took up my professorship at Ut
33:21 , we started working on, we doing work on the last chance Delta
33:26 went to U. Of H. started working on the Farrah Notam Delta
33:30 earnest. And that work began about . And uh since and of course
33:38 Wally and usually the 1st 1st 2 students at the University of Houston right
33:45 And they started their phds in about And we got finished in 2009 and
33:52 year later. And you can look the list of all my PhD students
33:59 and it keeps on going. And when I went to McMaster, these
34:04 McMaster students, these guys, all McMaster students that the final projects and
34:12 more. So I got up to students that worked on the ferret.
34:17 , now there's two ways you can a project, you can do what
34:21 Patterson did. Simon teaches at brand University has no graduate program only
34:28 So Simon just goes out every year has been going out for 30 years
34:31 himself Made with the old undergraduate, collecting data. My approach was to
34:36 33 students out over Well since 2005 we nailed it that way.
34:42 Either way we got a we got heck of a project. The trick
34:46 having 33 students says you've got to a lot of quality control,
34:49 Because they're all different and you've got make sure that in the end they
34:52 collect this day that's compatible with each . And so to do a lot
34:56 work to kind of make sure that , so there's a lot of mentoring
34:59 on here, right? You you got to spend time with all
35:01 students and make sure that you're confident they know what they're doing at any
35:07 . So, and, and this work was funded by A consortium
35:12 one point. I had 10 companies me at the University of Houston.
35:16 was kind of the glory days. consortium fee was I think 25-$35,000 a
35:23 . So I was pulling in, , about a quarter of $350,000 a
35:28 . And that was paying for a of students right that we, we
35:32 a good time, You know, to Utah and have a few
35:36 go do fieldwork. Yeah. Anyway went to the house and we found
35:40 guy in shanksville named Taco Van Leprechaun is dutch. He lives in Canada
35:46 he does his uh, he's a climber but he only slot slot climbs
35:51 the, in the early spring and fall of winter is never there in
35:55 summers. Of course we can't do work any other time this summer because
35:59 students are tang, even though it's there. And so, and he
36:02 always happy to have his rent this , he had a five bedroom house
36:06 a swamp or swamp air conditioner, couple of showers. It was
36:14 Yeah, he had two bathrooms, , that was great, you
36:18 And uh, and hacks ville was maybe half an hour drive from these
36:22 . So yeah, we we had good time of it from, so
36:27 work in 2005. 1st, students 2009 and uh, and I've still
36:35 a couple of students working on the and even as we speak, All
36:39 , their crops are amazing. You , the reason we picked these air
36:42 is there's not much vegetation and so can see the geology continuously exposed for
36:47 far as the eye can see. so the only limitation is just sampling
36:50 with enough frequency. They don't miss outs. Right? That's basically
36:54 Right. And even if you do pinch outs, you know, sometimes
36:58 can, you can correlate them with or just walk the sand stones out
37:03 between your measured sections. Thanks. here's an example of the delta it
37:10 . You can see there are a of pair of sequences here. There's
37:13 Big one you can probably see, a graduate student up there. There's
37:20 graduate student there, we do a of work on ropes. So we
37:23 a rope on the cliff and then the geology that way. Okay.
37:28 there's a DJ vu repelling down a and here is a couple of there's
37:33 Parco and Ryan Kruger measuring the right? So these J staff abby
37:38 and then and then basically work our up the outcrop or just use a
37:44 tape hanging on a rope. Just measure that the rocks vertically.
37:49 there's a photograph of the, of rocks above and then on the
37:54 there's there's a photograph of the rocks the various sequence boundaries, flooding
38:00 Ben, tonight's and other surfaces that students, e j ju who did
38:05 big dip profile, uh, sorted the fair and sandstone. There it
38:14 Lysistrata, graphically, there's the base it over lies a pretty thick unit
38:19 shales. Okay, that's the tonic . That's an interesting unit in its
38:25 right. You can see some little layers in the shale. Okay,
38:31 see them there. Those are the . So, the volcanic ash
38:36 Okay, those are critical for providing lower data. Critical. And you
38:42 also see there's all sorts of color in these shales. Many years
38:47 I managed to get another one of grad students, Zhang lei did his
38:55 on these shales with juergen Schieber indiana he logged the entire shale from the
39:01 of Dakota, all that to the , did a great project on that
39:05 the tanning shells. I see that is here so welcome. We're kind
39:11 just getting started in this lecture. just doing a bit of sort of
39:14 . Haven't missed too much. So just keep going if you have
39:20 just raise your hand. Let me . She also Okay, so there's
39:26 ahmed and she's walking out this bed . You can see it's got a
39:30 distinctive weathering popcorn weathering. Don't drive event tonight when it rains. It's
39:38 driving on Greece anyway. And they very distinctive, very soft in the
39:44 . They kind of have this light to sort of greenish color and of
39:48 they are rich in, in, , in crystals. Both zircons insanity
39:53 which the type of plastic plays. indeed have extracted those and sent them
39:57 to get dates, dates analyzed. the bentonite provide both critical chrono metric
40:06 as well as representing strata graphic data those are highlighted with the pink
40:12 Okay. Um, And there's the section that, that TJ put together
40:19 and we've actually revised that a little , pardon me. Where is
40:37 The calls? Uh, so this is the, this is the
40:42 and delta. There's a, there a little coal mine here that's
40:45 Yeah. We visit that number of and I visited some of the fair
40:49 coal coal mines. Yes. Uh, they're mostly cold. They're
40:53 digging kind of close to the Right? Yes. The mines aren't
40:57 deep. Most of the calls pretty to the surface. And so here's
41:02 measured sections and here's the same cross with the measured sections taken off.
41:06 Uj identified 43 pair sequences, 18 sequence sets, six sequences. And
41:12 show very well defined paris. You stack and patterns that define the various
41:18 . Tracks. Okay. And I through this last class, you've got
41:23 of paris sequences. You know, is faces little sort of delta front
41:30 pro delta transition. There is that in going from 15 - 14.
41:37 so that that represents a pretty major . Then that faces kind of starts
41:42 lift up so you can see it's into a grading. Then it starts
41:47 migrate landward. So that's the retro . Then it lifts up aggregation,
41:52 it starts to pro grade two Then it drops or degrades, then
41:56 drops again, then it pro grades it drops again. And so you
42:00 just you can you can pick any contact you want and track it throughout
42:04 cross section. Right? And whether track the shore line or the delta
42:10 to pro delta transition, Take a breath here, you know the pro
42:16 . The delta front of pro delta could shift a bit seaward if you
42:20 have a little bit of excess sediment . Right? So some of these
42:24 can be just caused by a little of local noise and sediment supply.
42:29 something like a physical drop of prophecies only produce by either uplift or sea
42:33 drop. Right? So some shifts faces can only be controlled by sea
42:38 drops and sorry, by sea level and others can be controlled by changes
42:45 sediment supply. So this boundary I'm is not the shore line and the
42:52 can also be, you know, you crank up sediment supply, the
42:55 will pro grade CRT. Another forum said that, you know, all
43:00 considered, you know, you big jumps probably represent sea level change
43:07 than just a bit more sediment or bit less sediment particularly drops. And
43:14 , you know, we're basically applying idea of of of of stacking
43:19 We've got various terms are the same . We can talk about the client
43:23 trajectory, the shore line, accommodation successions, para sequence stacking
43:30 they all basically mean the same Right? Just slightly different words.
43:35 advantage of using the word accommodation, , it gets you away from this
43:39 para sequence, which sort of implies scale. Okay. And and Jack
43:46 and vito bro said, well wait minute. You know, in the
43:49 of a clone, we can't see upward coarsening paris sequence. We can't
43:52 beds and bed sets. So we really use the term para sequence,
43:57 we can see similar project. We see similar patterns of chloroform uh
44:04 So why don't we develop a terminology a bit more generic and a bit
44:07 scaled at that? Okay. And that's why they came up with this
44:11 terminology. I can't like it. everybody does, but there you
44:15 Right. And furthermore, they pointed that that these that these these different
44:24 of stacking patterns reflect both magnitudes and of change of the accommodation to the
44:32 supply. So anytime you've got pro settlement, supply must outstrip accommodation,
44:38 means that the A. S. must be less than one.
44:43 If it becomes negative then you get . If it's positive but segment supplies
44:48 , then you'll get probation. And course when the accommodation is greater than
44:52 up to supply, that's the condition you get back stepping or retro gradation
44:57 transgression. Okay. And so on so forth. And then so that's
45:04 sort of the those are the that simple geometric diagrams that illustrate the concept
45:09 accommodation successions. And then here is designation of the accommodation successions in the
45:16 based on the analysis, the stack patterns of that cross section.
45:21 And I went through all this last . Okay, so I won't review
45:25 again in in in detail. Um you know, if this is not
45:31 perfectly dip components. So there is uncertainty in the in the trajectory perhaps
45:36 of some strike, uh strike lateral of deltas. Good to be a
45:41 bit careful, but and then now other thing we've done, which I
45:47 should put that all in here is new work that we've done is we've
45:50 this cross six and we've back stripped . So what we've done is we've
45:54 assumptions about the tectonic subsidence, the of substance. And we stripped all
45:59 out to generate a use static sea curve. That's brand new work.
46:04 put it that paper this week. . And so we're sort of doing
46:09 lot of work on the use static in these outcrops. Yeah, well
46:19 did back when I was here, have a church rob Stewart took a
46:25 team out, we collected seismic on outcrop. I spent a lot of
46:31 to take the team out there. data weren't great. He's got that
46:39 you can talk to rob Stewart and where is that fair and seismic
46:43 Yes. See. Yeah. Yeah. The problem is always its
46:51 seismic. You've got statics problems. got resolution difficulties. It is
46:57 right, right at the surface. the short answer is yes. We've
47:01 we also have sex like that of different delta that arco collected and it
47:05 very poor quality data. So there go. And of course we put
47:12 wheeler diagrams. We do have, , this is terrible. I do
47:23 real diagrams with the absolute dates. didn't show those to you. Those
47:27 are in in papers, they're not young anymore. But but anyway,
47:33 got wheeler diagrams, we've got a sea level curve. We now have
47:37 use static C double curve with the taken out and it shows unequivocal evidence
47:44 100,000 to 40,000 years to 20,000 years . So we feel pretty confident that
47:50 are melancholic cycles. And that's that's well demonstrated by by the by the
47:57 by the number of the number of and sequences that we see. We've
48:02 about six sequences in seven and 50,000 . So that's roughly, you
48:07 Divide by 750 x six. You 120,000 possibly. You've missed a
48:12 There's someone conformity. So now you're that kind of 100,000 year realm for
48:16 sequences. And so it looks like probably the short eccentricity cycles.
48:24 And then we talked some about uh, the non marine sequence
48:28 Sorry about the rap here. I have fixed that. And we went
48:31 that in some detail yesterday and here's strike section. So it sort of
48:39 around the corner here. So this section is oblique dip. Bc is
48:43 , strike the delta sort of program or less in that direction. So
48:50 not. Neither of them are perfect sections, but certainly this section has
48:54 much better developed climate forms. So want to talk a little about this
49:01 valley since we are sort of on theme of non marine faces. And
49:08 was the main PhD student, did lot of work on this sized
49:12 Uh Apoula did a big PhD on , as did David Kynaston, who
49:18 up, has been a series of students that did some smaller projects.
49:22 there's the regional paler currents. This based on 210 pale current measurements and
49:29 that the valleys of programming sort of northeast is a rough direction and there's
49:38 variability in there. So here's what outcrops look like. Um Here you've
49:46 one marine power sequence and flooding then you have another one, but
49:52 second one is cut by valleys and noticed that there is a white valley
49:58 , then there's a sandy laminated valley and then there's the youngest valley.
50:03 you notice that this has beds that kind of dipping from left to
50:08 And on lapping this Valley three which is a big stack of Sandy
50:13 beds. And then the youngest valley laterally creating in the opposite direction to
50:18 . two and V. One, . Two and muddier. And
50:21 Three is a bit sandy in this , although the faces and feel very
50:27 , but it's not uncommon that we three amalgamated cuts. He also knows
50:32 V two cuts out V three. , we see evidence some of the
50:37 valleys are deeper than the older You get the idea that there's terracing
50:42 on. Right. And so this one of the world's first projects where
50:45 could really convince myself that we were evidence of terrorist deposits in a compound
50:51 film. Here is another example, of my favorite photographs of all
50:59 So what you see with the dashed line is a big channel form
51:05 See that the channel foreign feature. is that above it there is a
51:13 plain, coal rich mud stone and there's a sandstone here. And with
51:18 eye of faith, I think you see well developed lateral accretion. See
51:22 ? So here we've got a Okay, there is the channel and
51:30 is, there is it's it's channel and it kind of comes up to
51:34 zero line here. And so we a point bar overlying a floodplain that's
51:44 within a larger erosion all feature. ? So here, you can clearly
51:49 there is the largest scale valley and a smaller scale river and floodplain inside
51:54 valley. Right. And we we both Ben Hilton and David Kynaston mapped
52:02 , that you can actually map this valley floor locally and you can see
52:07 of tributary valley fills coming in. quite an interesting system. Now,
52:13 is the base of That would be . three And this is v.
52:21 . Okay. And then Valley one actually on top of a bit
52:27 So we see the three terraces in slide and we can see the three
52:30 and these literally This outcrop is maybe m away from that one that's on
52:35 side of the valley and then that's the other side of the valley.
52:40 you stand at this area where the comes up, that in the
52:44 that's the inter flu, you see examples of, of roots sticking
52:48 So that's, that's the air that high dry. The water table was
52:52 and the roots dug down to get the water. Eventually seen an erosion
52:56 into coles. Right? But these that are digging down in the sand
53:00 get to the water below, That's time of non call. Right?
53:04 the relatively dry time. So the of, we see evidence of water
53:08 water tables associate with these inter We also see lots of evidence for
53:19 much more muddier floodplain sediments. We've sandy caress plays with Kohli floodplains and
53:26 green mud stones with all sorts of slicking sides indicative of paleo Sauls.
53:34 And here's what those soils look Again, they're filled with beautiful route
53:39 and here's an example where there's actually hey bush, there's the trunk of
53:45 bush and then you can actually see twigs and branches coming off on the
53:49 of the bushes, sits, stood a paris flight buried the bush with
53:56 and the bush is still preserved in Uh and it's been there for 90
54:01 years. Pretty amazing. We see of tear apart or dinosaur footprints.
54:10 the toes. This is the fossil I helped to find which is the
54:15 vertebral column of this parasaurolophus. So see evidence of dinosaurs, both footprints
54:25 bones in these outcrops. Again, this to be a non marine
54:29 Right? You got trees and sit . You got dinosaurs walking around.
54:34 what more evidence could you want This is normal. Here's another example
54:38 , about a maybe a kilometer away the previous outcrops, same valley
54:44 And you can see beautiful upward coarsening sequence. Here's the next one And
54:51 next one is it wrote it into the incised Valley. Okay, if
54:57 look carefully at the top of the valley, there's a beautiful laterally creating
55:02 bar and if we draw the channel can see it's much smaller than the
55:07 of the sand boarding. So once we see evidence of a unequivocally multistory
55:12 bottles. If you look at the of the youngest channel belt and we
55:17 of draw that thickness. We see the the the the valley fill is
55:21 least three full stories thick. of course we can trace the marches
55:26 valley regionally until we get to the where it actually comes up to the
55:32 flu. So we know that the relief on that red surface regionally is
55:37 27-30 m. And the depth of biggest distributor or Meandering channel we've seen
55:46 maybe 5-6 m. And that would be the towel wag depth. So
55:51 main bank, full depth is probably m. Right? So we've got
55:56 3-4 m channel Mean Bank, full . That's cutting a 27 m deep
56:02 . So again, unequivocal evidence for valleys. We've done a lot of
56:07 on the betting diagrams. So again white arrows point to the base of
56:13 large valley. The valley is is km wide, 40 kilometers wide.
56:24 what what does the width of the correlate most with? No, well
56:35 maybe ask the question differently. What's main control on the width of the
56:41 ? We talked about the things that scales of values. What nope,
56:47 would control the discharge. Obviously the of the river has some control.
56:57 is this is the one that students the most and again in the context
57:03 the fairyland talked about, we've seen very small valleys And now we've got
57:07 of those 40 km wide where some the other Valleys 100 m wide.
57:13 that's that's two orders of management That has nothing do with tectonics.
57:19 are you static values. What does take? No, it's not subsidence
57:29 would cause the valley to a What's the main control on the,
57:45 width of the valley? So the is doing its work. Right.
57:58 would allow river to do more Very short. This stuff is all
58:12 soft. What controls the ability of river to do anything stuck in the
58:47 back there? And one of yesterday's . But these are small rivers,
59:09 ? 4-7 m deep. How on does a 47 m deep river produce
59:15 40 kilometer wide incision for me. could one flood event produce a 40
59:26 wide Valley and 47 m was gonna flood the valley and finish it.
59:41 , appreciate so again, right. okay, but it literally migrates because
59:49 has enough. I'm looking for one . All right, nope. Assume
60:01 those are all constant. But why, why is the colorado?
60:11 is the colorado colorado river cut the Canyon. It's not that big.
60:16 river. What allowed the colorado river cut a mile deep canyon?
60:25 it's not the next point. The Canyon is not really a knick point
60:31 feature. The entire colorado plateau has uplifted. So what's the main control
60:39 why the Grand Canyon is so doesn't do with topography. That's
60:49 Right. It's difficult to row and it's bedrock. You guys are gonna
60:57 yourself when I give you the When did when did the colorado River
61:09 cutting? That's that's a hint, me. Okay, there is some
61:30 that was that it started the So how many years is that?
61:37 still there today. Time. Have you guys ever read Lord of
61:42 No the Hobbit where he's having the with God about the riddles. It's
61:48 eats all cuts, all erodes And he's he he asked for more
61:54 . But that's the answer. Don't forget about. But this is
61:57 whole part of this talk is to to give you feeling for how much
62:00 it takes to form things, 40 km wide valleys and small rivers
62:06 only be cut if there's a lot time to do it. Right.
62:09 we know that this is a much lived. So in the note
62:13 the low stand was much longer lived it was in the last chance.
62:21 . Mhm. Now there is some on the betting diagram of bidirectional down
62:26 indicating that there were braided rivers. there is some notion that incised valleys
62:34 start being braided because if there nick generated, What does the nick point
62:47 ? And what what what favorite brady is favored by an increase in just
62:56 so. Right. So if you an increase in slope, you tend
62:59 produce braided rivers. Right? So not surprising. So in that sense
63:04 don't want to be over critical of idea that that the falling stage and
63:08 rivers can be braided. Who's commonly represents an increase in slope. And
63:13 you increase the slope, murders will to be more likely be braided.
63:26 at the base of this valley, see these mud stone rip ups.
63:31 little white dots represent pebbles. So see coarse grained lag as well as
63:36 grained material Cabot carried by the Here's an example of some of the
63:42 attic alluvial faces. So we've got grade uh pebbles in a cross bedded
63:53 . There's an example of small scale bedding with a hammer for scale.
63:57 the cross bedding is dipping in the direction and as we go into the
64:02 parts of the valley fills. Sometimes see these little vertical trace fossils.
64:08 some of these mud stones were getting marine donna, Flagg glitz and marine
64:14 , adults. So we're seeing some water and marine influence. Sometimes we
64:20 good evidence of double mud drapes. one there maybe maybe another one there
64:28 these double mud rapes are all these mud rapes are pretty typical of,
64:32 , of tidal influence. And then is one of my grad students next
64:38 a nice pinch out on channel, can see the lateral accretion in that
64:43 going into a cut bank. Here's example of a laterally creating channel.
64:50 one is over land by coal. interesting the coal is very difficult to
64:54 . So in this case the channel migrates like gangbusters over an old coal
64:59 or probably no pete. And then much younger channel occupies the area that
65:05 older channel used to be and eventually the older channel out and even gets
65:10 and cuts out that hole. And here's an example of laminated mud
65:15 . That's a floodplain and there's a growing in it. Probably some sort
65:19 mangrove and then that was the top the flood. That was the top
65:22 the floodplain lake and the rest of tree has been oxidized away.
65:31 We're sort of at 65 minutes. think we'll take a little Break.
65:35 I've got 90 slides in this we're almost at 50. We're about
65:39 through. So take a break, a 15 minute break. What time
65:46 it? 10 15? So Start at 10 at 10:30. Does that
65:51 good? No, and I hope I want all my little, my
66:06 stories, you know, kind of trying to make it a bit more
66:11 . Not that geology is not Anyway, so what was interesting
66:15 you know, I started this it's sort of close to the beginning
66:21 telling you how many students have had work the area, right. And
66:26 know, I was looking at google of this area for years and I
66:32 realized what I was looking at. I was looking at this map and
66:35 said, wait a minute. These meanders. Girls look at them,
66:42 another one here and there's probably an channel here. And although it's not
66:52 , this is an outcrop, the cliff here. And you go in
66:56 and you can see that the margin this channel is right there, see
67:00 pinching out perfectly. So um and can see that there is, you
67:06 , this kind of a meander belt . There's a channel coming through
67:12 There's another channel coming through here. that's some sort of shoot channel cuts
67:19 the meander. So we began to that we've got exposed views of these
67:25 meander belts, right? We get feeling for the, you know,
67:29 width of maybe a passive channel Phil so on and so forth. And
67:33 can see some sandy bars here in channels as it kind of migrates in
67:39 direction. And Chen yang wu did over this outcrop with his Brunton and
67:48 measured all the paley currents. So of these triangles points in the direction
67:53 flow and it's beautiful. It just around exactly like you'd expect. So
67:58 can see how the currents are changing plan view. And of course here
68:01 an example of these ribs and furrows that point in the flow direction and
68:09 more examples here you can kind of . So you can walk around these
68:15 and get all these paley current measurements we can sort of reconstruct the flow
68:19 if you like. And then this grain size. And so you can
68:25 that there's courses grains on the outer of the channel where its deepest kind
68:32 makes sense. And then we see uh we also see evidence that that's
68:37 bit coarse grained upstream and it's a finer grained downstream. So we can
68:41 downstream finding finding the point bar as as the finding from the inner as
68:45 as core spinning with finer grains on interbank and coarser grains on the outer
68:50 . So it allows us to mount green sizes in plan view. And
68:57 is useful information. You don't usually this kind of these kind of outcrops
69:01 ? And this gives you feeling for for the changes in grain size,
69:05 of course ultimately reflect changes in process credibility and would would would speak to
69:10 this point bar would produce oil and wasn't buried in full of hydrocarbons channing
69:18 kind of did a little reconstruction of history of the development. So it
69:21 off as a relatively straight channel becomes little bit more sinuous through time reaching
69:27 maximum velocity and eventually the channel re this whole position and these these this
69:35 channel gets plugged up of course, you've got us, that's kind of
69:40 final version with his little plugged up . And so of course, with
69:46 our crops like these, you can a pretty good idea of the width
69:49 the river versus the scale of the belt. We've got good information,
69:54 outcrops that give us information on the the channel and as I said,
69:57 have this this particular channel is well in raise it again. Yeah,
70:10 . Down here, this is where channel is well exposed. We're looking
70:13 this particular shower belt in the subsequent . Yeah, the outcrop belt is
70:25 of in here. All right. so we have an idea of what
70:33 depth of the channel is. And , here's our measured sections where we
70:37 the base of a channel, finds to ripples, base of a channel
70:41 beds going up to the ripples. the ripple faces would represent the upper
70:47 of the channel. The doom scale beds would represent the main main parts
70:51 the bars. And so we've got pretty good idea of of what they're
70:56 the thickness of a full channel Phil okay. And then this is the
71:01 form phase diagram. Bill Dupree probably about that. And so you can
71:06 that for. And so we've got depth on the vertical axis, we've
71:11 velocity on the horizontal axis. And we've got the various bed forms that
71:17 stable at any given combination of depth velocity. And so in the Faron
71:23 observe Doom scale cross beds. But observation of all these cross beds requires
71:29 to be the stable bed form, know, from the base of the
71:32 , all the way up to the at which the flow slowed down,
71:35 it finally slowed down into the ripple . That indicates waning flow.
71:41 And so if you want to understand maximum velocity associated with migration of these
71:46 , right, If it got too , it would it would wash
71:48 You get up a flatbed, you see the upper flatbed, and we
71:52 sees dunes. So we never got this line here. And we only
71:57 we only got lower than that line separates the dunes from the ripples during
72:03 waning flow. What that shows is for, you know, a five
72:07 67 m deep channel like Faron, velocity range in which dunes are stable
72:13 about 75 to 150 cm/s or about To 1.5 m/s slower than that.
72:21 gonna get ripples fashion that you're going get upper flatbed. The other
72:26 which I hadn't appreciated that is that stability of dunes is relatively insensitive to
72:30 depth of the flow. So whether depth 20 m or 10 m,
72:35 flow velocity in which dunes is stable about a meter per second. If
72:39 gets up to three m per even if it whether it's a 10
72:42 deep channel or two m deep it's going to be up a
72:46 Right? And so this is the you can use the observation of the
72:50 structures, whether it's an outcrop and and if you know, and you
72:55 even really, really need to know channel deaths because the sensitivity of the
73:00 form to trail depth is low, ? If you've got dunes, then
73:05 probably, you know, if you've dunes and you don't know what the
73:10 at all, you can say you're somewhere between uh, you know,
73:16 to maybe 50 centimeters to meters per , 2.5 m per second.
73:22 the likelihood that you have a 0.1 deep flow is, is if the
73:26 beds are bigger than 0.1 m, know, it can't be that small
73:29 there are no rivers or 100 m . So, I mean, you
73:32 , you can, you can pretty get to a velocity that's within a
73:38 of two or three using this of course, once you've got the
73:46 right, once you've got the you can here's the velocity shows the
73:57 , this is the manning equation that the velocity is equal to the hydraulic
74:02 , which is essentially the depth times square in slope. And if you
74:07 what the velocity is, you know the depth is. You can solve
74:10 equation and get slope right. So are the ways you can use some
74:13 these parents. Hundreds of equations to things that you might want to
74:18 And again the slope is going to and changes the slope. They're going
74:20 be cause things like nick points, going to drive things like incision and
74:26 in slope. Also required some sort tectonic tilting. Right? And then
74:33 course, if you know the velocity you know the cross sectional area of
74:36 channel, then you can calculate a discharge. So we go back to
74:42 strike section and that allows us to mapping the the plan view. Paleo
74:50 of these deposition systems here, we've a short face and yellow river delta
74:55 green and overlaid by channel here, channel there. And so there's the
75:02 geographic reconstruction. So there's the there's obliques tricare crop belt. There's the
75:11 dip outcrop belt. And so that's that's the geometry put together for this
75:17 . So it looks like you got incised valley. So the incised valley
75:24 books. Yeah, the inside's valley , is this thing here,
75:36 There's there's the incised valley, there's inter flu and its size all the
75:39 to that point there. And then get these delta system that it feeds
75:44 number six, there is a cross in this section here. The incised
75:52 here, and we've got a short here and there's a short face on
75:58 other side and it's not intersected by cross section and we've got a delta
76:02 the middle. That's basically how we them out. Not that not that
76:09 again, what that allows us to is to link a given in size
76:15 river with the associated delta. if we know how long that river
76:25 cutting, how long that river how long that valley existed.
76:29 This comes back this issue of time we can get an idea of the
76:34 because we know how many power sequences are, We know how many sequences
76:37 are, We know the total amount time. So, if we
76:41 you know the six sequences, If take a 7 to 50,000 years to
76:45 that by six sequences, we get on the scale of about 100 20,000
76:50 per sequence. And the sequence includes incised part. Transgressive partner Hiestand
76:57 So we just say, well, third of its associated with the falling
76:59 and low stand, Maybe the river sitting in that hole for 20,
77:04 , something like that. Right. not perfect, but it gives you
77:07 of a Some idea, right? know? And boy, if that
77:11 was sitting there for 20,000 years, enough time for it to cut a
77:14 wide valley. So the width of valley is compatible with the amount of
77:18 that we have available for that river be, to be working Now.
77:24 also have mapped the limits of the directly fed by the river, so
77:29 the sink. Remember I talked about to sink so we can map that
77:34 , we know how thick it is enough places that we can, we
77:37 get a pretty good idea of the of sand in that sink. So
77:43 we've got a river That sat there maybe 2,025,000 years something like that.
77:50 feeding sediment into that sink and we've an idea of what the discharges in
77:58 in, in m3/s. That gets bit of a problem. How do
78:05 go from cubic meters per seconds, kilometers of sediment per year delivered to
78:11 , to the shorelines? And that's tricky part of this source to sink
78:18 . However, you do what good do use empirical methods. There's lots
78:24 folks have compiled flood frequency and recurrence for global rivers. We've got some
78:31 on what the climate was like in and time. We know it's not
78:35 very big system. There's only, was only a few 100 km from
78:38 shore line to the mountain front that these probably didn't cross any climate zones
78:43 the, in the process. We've palan ology that tells us this in
78:48 is an ever wet environment. Not if it was monsoon or not,
78:52 all of that, all that kind information can be modeled and extracted,
78:59 know, a pretty good rule of is that most rivers are in flood
79:03 maybe 10 to 15 days a And the rest of the time rivers
79:07 doing very much right. I how many, how many, how
79:10 weeks a year to the texas rivers flood? Not every day, not
79:16 week, maybe once twice a You know, maybe a week or
79:20 years. You got a bit of . And so that's generally true.
79:24 ? You know, uh and so go look, okay, So If
79:27 assume that the rivers were, were that maximum discharge for say 14 days
79:33 there was a flood maybe once every years, maybe a recurrence frequency of
79:37 years, then you can say, , so during that 14 days and
79:43 it was 1.5 times a year, it's 14-plus 7. So maximum 20
79:48 of, of, of, of discharge year, you can convert the
79:53 discharge to a discharge for that flood . There's also empirical equations, you
79:59 use to say if, you know water discharge, you can figure out
80:03 much bed load and how much sediment load the rivers were carrying. It's
80:08 empirical based, right. There's lots empirical civil engineering data on this.
80:13 , there's uncertainty, but that's what did. Okay. Now, what
80:18 did was calculate sort of some medium and high cases to give us
80:21 ranges Gabe. So we've got we've some, you know, a range
80:27 uncertainties on the mean bank. Full From ranging from 3.3 up to 5.5
80:33 deep, Which could range from 75 to maybe a couple of 100
80:39 You've got some some constraints on that sizes. Again, we measured
80:45 I already told you we've got some good ideas of slopes. Right?
80:48 in general, the slopes are kind now here saying that the sort
80:52 you know, 3 to 5 times to minus four, We've got some
80:56 of velocity ranging from 1.6 to just of two m/s. Then we've got
81:02 estimates of water discharge From maybe a 100 up to a maximum of
81:09 Uh And then based on that, can calculate an instantaneous bed load
81:15 And then we simply integrate that instantaneous load transport in cubic meters per
81:21 Assume that the river is in flood 14.6 days per year. And that
81:25 us an average yearly bed load. ? And then we multiply that by
81:30 duration that we think the river was in this case, we thought it
81:33 be about 14,000 years. And that us a total bed load volume
81:38 In a billion cubic meters. And I think that that results in
81:45 in three, 2, km3 of . Well, now we've got a
81:52 , we can compare that directly to map volume of, of, of
81:56 in the actual uh area that we and see if it makes any
82:03 Okay, now, the total amount sand that we map. So this
82:09 here, Okay, we figured that about 2.4 km3 of sand.
82:18 Our low estimate said that the river have delivered, delivered three km cubic
82:23 of sand. We map 2.5 cubic . That sounds pretty like a pretty
82:29 match to me given the uncertainties. we said it could be as much
82:34 10, of course that would you know, that there's less probability
82:38 on the high side. Um Let's that, let's say there was three
82:44 bit more. What that would tell is that maybe we've lost some sand
82:50 that, that not all the sand river delivered, is there, wait
82:55 minute. We've also got ashore face we know that some of the sand
82:59 coming out and some of it is carried down drift. So when you
83:03 the shore face in, you add few cubic kilometers of sand. And
83:07 when you go into this offshore, still quite a lot of very fine
83:13 into bed with those pro delta And it's not, it's a nontrivial
83:18 . The flip side is most of very fine sand is being carried as
83:21 load, not bed load, whereas lot of the short faced sandstone is
83:26 sand and would have been carried as load stops at the mouth bar and
83:30 get reworked. We reworked down So in the end we felt that
83:37 , we thought that the uh the estimate that we made of the scent
83:42 in the delta can be accounted for we probably had a significant amount of
83:47 transported along shore in the longshore drift . So we were pretty excited about
83:55 because it sort of told us that sources think estimates seemed to be kind
83:59 certainly well within an order of You know, the, the sediment
84:04 estimated was being delivered to delta was with an order of magnitude of the
84:09 that we could map in the actual sink. Now suspended loads a little
84:14 harder because the clay can go anywhere . And the mud load is typically
84:21 times the bed load. But that us some idea of what the total
84:26 budget is in the basement. Not course becomes important if you're playing those
84:31 those mud stone plays. The other we're interested in was constructing the size
84:38 the drainage basins and uh and we some work on that. I won't
84:43 won't go into all the details on . Now another thing that we thought
84:50 was so the slide on the left unpublished. That was the map that
84:58 . J. Made of of the the of that sequence too. Indifferent
85:06 sequence. One of the youngest sequence is the one that we can link
85:09 the shore faces. The youngest sequence ends in florida and we don't know
85:13 it fed that that that the the is missing. It's up near and
85:17 away and you j mapped a single narrow valley and you know, we
85:23 that was a perfect good map. know, he's got his values being
85:28 a kilometer wide. But I just telling you the Columbus, 40,
85:32 valley is 40 km wide. So this map needed some revision.
85:38 Also the parallel currents kind of show rivers are programming that way. But
85:44 the area that you j had no , he kind of suggested that the
85:49 coming from the south Thanks. And know, here we've got the po
85:56 basin, you know, that's you , Alpine basin and eventually it all
86:04 into a single trunk river and finally is little delta, right? So
86:09 is the source to sink systems for and so the idea is maybe this
86:13 a prototype system. Now there was a a couple of hypotheses. Jim
86:24 , we talked about a little you know, put together the geology
86:28 the Faron notam. And and this parrots delta, which is where ki
86:33 worked and suggested that maybe most of sediment is coming from the south.
86:39 the cretaceous interior seaway has a western and then it's got a kink uh
86:48 these Mongolian highlands are, and they an old rift shoulder uplift that provides
86:55 that builds to the north. In , you got the severe or genic
87:00 and the cordillera magmatic arc that delivers from the west. So we have
87:04 completely different source distinct systems. what's interesting is they have very different
87:10 historical signatures. The Mogollon Highlands, 1.81.9 billion year old Zircons. Where's
87:18 cordillera magmatic arc is cretaceous zircons and fold and thrust belt is largely
87:25 Okay, so one hypothesis is, got sort of one single large major
87:32 system and it deposits the Norton then the last chance then back steps
87:38 feeds the corporal. It's and maybe vernal delta is in there somewhere.
87:44 there's a completely alternative view, which that each of these deltas is fed
87:48 completely different drainages, a much more style of drainage. That was a
87:55 that tom rare, who unfortunately since away, but he did a lot
87:58 work on the Faron in the you had to completely competing hypotheses who
88:04 this big river that was convulsing over producing these big delta wedges, or
88:10 had a bunch of rivers feeding deltas was sort of coalesced. Uh you
88:16 , a series of coalesce deltas and you'll permit me. Mhm, just
88:42 me a sec here. Remember in slide, we talked about the fact
89:20 when you're in the basin has low glacier aesthetic changes. And the
89:28 we've got changes that are 50 m about the maximum change. Again,
89:33 small compared to Icehouse Times when it be over 100 m or more.
89:41 what that means is that even at stands, you just don't have enough
89:45 area exposed to allow rivers to converge make big trunk rivers. And so
89:52 cretaceous is more like the Canterbury where all you ever has is a
89:58 of smaller rivers. Maybe there's a bit of chance for one or two
90:01 come together when sea level drops, but not so much. Okay,
90:07 to go back to that point. anyway, so we've got these these
90:30 hypotheses, you know, one is we have sort of just one major
90:33 river that fed a bunch of the others, we just have a
90:37 of rivers that never quite came And if that's true, we should
90:41 differences in to trial Zurich, on vernal should have no Mongolian uh to
90:46 to, Zurich opens the last chance , probably none. But we might
90:51 the notam and the comparison to be rich into tribal zircons from the Mongolian
90:58 . So my PhD student, David decided to sample the Notam Delta and
91:05 sampled the various terraces in this compound filled and so reminding, reminding here
91:13 that compound valley fill in Nielsen Walsh we sampled each of these different
91:22 Now we are also very influenced by bloom. So mike bloom was working
91:26 the gulf coast deltas and showed you a bunch of small rivers, the
91:31 that browses the colorado and so and forth. And at low stands,
91:37 they remain separate sometimes, for at low stand, the tyranny and
91:41 come together and the colorado and this river coalesced together. So you might
91:47 a couple of rivers coming together, a slightly bigger delta at low stand
91:51 that high stand. And rather than mhm rather than sticking with the jays
91:58 of a single big trunk stream, browser style dave Kinison went ahead and
92:04 remapped the valley system and said, a minute. It looks like there's
92:11 separate river systems that are feeding this . So it's not one delta fed
92:16 one river. So in fact we 47, maybe it looks like the
92:22 these coalesce, you know, there's crosstalk hair. Okay, So he
92:26 forced his map of the valley to more like the fraternity of the gulf
92:32 . So we're using the modern to how we envisage the the ancient As
92:37 to just assuming one Trunk Valley and a map that it was good for
92:42 day, but perhaps wasn't so So here's an example of the two
92:49 or con data and I'm not gonna into huge detail on this. But
92:55 you have is is whole bunch of here. So blue represents the old
93:06 , I think represents the older Uh pink represents the younger terrorists.
93:12 we've got a judge from left to . So 4.5 billion years on the
93:16 , zero on the left. You see this huge peak in about 90
93:20 years. Those are the zircons that coming from the volcanoes. And you
93:24 see some of these zircons have a of yellows. That's a lot of
93:29 stuff. Okay, then you can this blue peak. It's very high
93:33 some of these samples, some of samples have a mix of lots of
93:38 and the blue is Mongolian and some there's almost no Mongolian or it's it's
93:44 , it's very subdued and we get greens and yellow, which is coming
93:50 the corner and fold and thrust So it's very clear. So here's
93:56 here's the various regimes, You've got severe fold and thrust belt, the
94:01 highlands. And then you've got the magmatic arc. Okay. And the
94:07 Highlands have this very distinct blue The severe has a subdued Mongolian peak
94:14 it's got a much stronger green and peaks which represents Grenville Ian too,
94:23 fold and thrust belt sand stones in , which is uplifted paleozoic rocks.
94:30 , the Jurassic early night, which be the Navajo which covers the whole
94:34 and erosion of the Jurassic Navajo probably some of that sand got into
94:39 and again, that has almost no peak and it's got mostly grand village
94:46 and a lot of paleozoic stuff. , so it tells us that
94:50 some of the sand stones had a contribution from the fold and thrust belt
94:56 some of the sandstorms were mostly drive erosion of the Mongolian highlands. So
94:59 actually have two separate river systems feeding big delta complex. So the
95:05 by definition is fed by different drainage . It's not what we were expecting
95:10 all. In addition, this was nice little thing. We did some
95:16 basic old fashioned photography. I just at Montecristo in courts feldspar analytic fragments
95:22 we found that the sand stones derived the southern Mongolian areas. We're,
95:30 showed a transcontinental to mixed tectonic affinity they were more or less uh fellas
95:40 , whereas the severe material was. definitely lit carrionites And they that represents
95:47 blue crosses exit. Sorry. So saw very, very distinct and separate
95:54 composition. Right? Here's why this valuable. This is much cheaper than
95:59 the tribal zircon work. You gotta the sand stones to segregate them.
96:03 got to separate the zircons. You've to irradiate them. You got to
96:07 them. You gotta zap them in mass. Spec it's 600 bucks for
96:11 do. We actually get them done cheap. We get about $5 is
96:15 but you do about 300 Americans per . You do four or five
96:19 And your it's 3000 bucks. The work, Take a sample cut a
96:25 section for $10 and take spend a hours looking at microscope. And you
96:30 , but of course without calibrating the to the cut to the basic
96:35 You know, Now we've got that can do more of that. We
96:37 to worry about the zircon so So. David. Uh whoops.
96:45 matt. Um The so these are the the the general we saw three
96:52 , right? We had the we the Mongolian source valley. Now this
96:58 this is valley. Three terrorists. , what's interesting in terrorist three is
97:02 the northern valley shows more corny Aaron sheets and the southern valleys McCoy in
97:08 . So it's that's nice too because tells us that the southern valleys represent
97:13 that were draining from the south north the northern valleys represented rivers were draining
97:18 the west to the east. And the segregation of valleys is rather nice
97:23 does show us That that the older was formed by two separate rivers draining
97:29 areas. We see an increase of in source, in valley too,
97:34 with only a little bit of of source material, western source material,
97:38 of it from the south and then southern valley. We see um
97:44 in the youngest valley we see evidence a much greater sourcing from the severe
97:50 thrust belt. So very complicated source sink relationships, not what we were
97:56 at all. Young young lee was student of mine who did work in
98:02 north area and in a series of aerated cross sections. Very nice work
98:08 the various valleys. We did a of work in this Nielsen wash area
98:13 that wait while we had done then valley dive subsurface. We want to
98:18 at the northern area which was maybe 10 km north and see if if
98:24 valley looks the same. Young young that the oldest valley is more tight
98:31 or flood based the second terrorist is capped and the youngest family shows almost
98:38 estrogen influence at all. That was . We saw the oldest family looked
98:43 it was more tight influenced, so in segment, remember we talked about
98:48 maybe closer to the shore line. valley two looks like it's a bit
98:52 away from the shore line and V looks like it's the furthest away from
98:56 shore line. What would that correlate ? So we're looking at, we're
99:02 at one place in the photography, got message valleys and the valley fills
99:07 getting more flu viel as we go . What could control that. We
99:17 this was a pretty clever story The gun. Well that changes
99:29 Now here's the wheeler diagram, But is the interpretation at time one the
99:34 cuts, but it's, it's pretty to the shore line. So it's
99:38 the title backwater because this is a along long lived forced aggression at time
99:47 the next valley cuts and now the is further away. So it takes
99:54 . In this, let's maybe drop a still stand for any marine influence
99:57 enter the valley at a time for shoreline drops yet again and the valley
100:03 deeper and it's just too far away the shore line to ever be marine
100:08 . So, exactly right here's a diagram of the entire valley system
100:15 just emphasizing the dark chris nature of terraces that overlying the value fills and
100:23 oldest ones tend to be marine influenced they got more fluid, real
100:28 and we think that these are younger not 100% sure, but looks like
100:33 . One, V. One cuts V. Two. Anyway, of
100:38 , just to go back to sort wrap this part of the story
100:42 you know, originally in the in excellent sequence trickery, they had very
100:47 sea level fall and the assumption was there wasn't much time to generate
100:53 So you everywhere just produces degradation of . So I just introduced a new
101:00 . Right. And incised valley is elongated topographic load cut by a river
101:06 smaller than the elongate topographic low. that fit the definition of an incised
101:20 that I just gave, yep, that are smaller than the topographic
101:33 So does that fit my definition of incised valley of suit. And so
101:51 would say no and I would always yes. So the problem is On
101:58 Diagram, we've got four separate and values at least two of them.
102:05 blue one is rivers draining from the and the pink is reversed rating from
102:11 south. So, you know, hard to call this one incised
102:17 It's an incised landscape. You there's four separate valley systems. So
102:23 thought, you know, I thought calling this a mega valley because of
102:27 witch, maybe it's just a degradation landscape. You know, that consists
102:31 a series of adjacent valley systems, ? For valleys that form a valley
102:38 at any rate. Clearly it's it's not a simple incised valley.
102:42 it's at least a compound valley, it's not only compound in terms of
102:46 cutting fills, it's also compound in of multiple valleys over a wide
102:51 Right? You know, that's 40 of of separate sized valleys with inter
102:57 in between. And you know, not what we're expecting, but you
103:03 , but it looks way more like modern incised valley system which you have
103:07 rivers at the coast like we see the gulf coast that might bloom
103:11 So we really forced this um we forced this map to look like the
103:18 . Now I'm getting a bit upset now because Dave tried to publish his
103:25 . Dave's problem is when he writes paper gets so huge, gets a
103:29 hard to manage. It got rejected revisions and that was two years ago
103:34 we haven't got around to making the . But I like I love this
103:39 , I need to kind of take just kind of clean it up and
103:41 it a bit clearer. Right? because that's a really important story to
103:45 told right? He did get one out where he described his tributary valley
103:50 kind of a whole separate, complicated , but we didn't quite get to
103:55 the story of this mega valley system I think he got a little bit
103:58 in the forest and the big story missing. But I don't know,
104:05 got a book to write, I've these papers that I have to
104:09 I've got this class, I gotta , I've got a life to live
104:15 I'm not, you know, I'm, I sometimes think I'm a
104:18 lazy. Like I like to sleep , you know, I don't,
104:21 like to work smart and focused. told me I'm a workaholic. I'm
104:26 , I'm not a workaholic and I my weekends off. I'd like to
104:30 to my wife, listen to go to concerts. But then I
104:34 all this stuff that I'm like, , I should, this should be
104:37 . Right? Mhm. So so that led to this figure,
104:44 is in the, well I say new. I feel like I wrote
104:47 yesterday, but it's quite a few ago that john Holbrook and I wrote
104:51 , john Herbert wrote the paper and kind of added to it. So
104:54 bypass model is sort of the quintessential model for sequence photography, right?
105:00 know, you you, you, cut a big valley. So a
105:04 topographic valley with maybe a few scrapping deposits and most of the fill is
105:09 , low standard transgression in contrast. say, well, you know,
105:14 river cuts and it cuts more but it sort of leaves terraces
105:19 So in the end you get a that looks exactly the same. The
105:23 is the erosion of surface was never at one point in time.
105:27 he liked the strong and popular idea of a strata, graphic erosion surface
105:32 would know there was never a topographic . And we sort of had this
105:37 that is that the river is cut then cover the irrational surface kind of
105:43 leaving terraces of potentially quite widely different , producing a strata. Graphic erosion
105:51 that has very widely, that has that cover a wide time span such
106:00 a falling stage terrace might feed a downstream. And as the force progression
106:07 and the sequence banding rights over its deposits over a young adult deposits.
106:14 sequence boundary ends up lying on the of young delta deposits with older terrorist
106:20 above the sequence boundary in a more position. And that gives that annoying
106:25 of all terrorist deposits above the erosion surface landward. And that erosion surface
106:32 is actually younger because it's Dia Cronus overriding younger delta positive seaward direction because
106:38 sequence boundary is highly dia chris. , so it's not a single through
106:46 time surface. Anyway, this paper received over 100 quotes. So,
106:53 are paying attention to that story. , the last thing that we did
106:59 the Faron mm hmm. The last we did um was went to the
107:11 south of fremont river, lots of in this sweet water wash everywhere
107:17 And you know, some of the , the clips are pretty high up
107:21 that the marine stuff was all below surface. But this beautiful low network
107:26 political stuff was perfectly exposed and easy get around. I was reluctant to
107:31 that first because I wasn't quite sure photography. So this was a later
107:36 and a bunch of bunches of to students stand fixed to Susa and Omar
107:43 and then family photo we just call bodega for short who was one of
107:49 Nigerian students were a nice guy and decided to do a fairly small
107:53 Can't say anything about panty Sauls and know, but it is a real
107:57 person to shy but outgoing at the time. And he tunneled off too
108:04 and did some work with steve Greasy is a world expert in panty souls
108:08 steve gave us some excellent advice that him understand the the palace also
108:15 So we've got, you know, marine power sequences. We get the
108:19 valley, a nice compound, incised and then we get this inter bedded
108:24 , mud stones. This is all marine and then there's a sharp contact
108:29 into transgressive blue gate shales. The of the, of the sort
108:32 one of the last projects was on to rip apart this low nut to
108:38 package. And remember when we talked sequencing, we talked about pay Lysol
108:43 Right, Marriott. And that So I thought, well let's see
108:46 we can find out what the police surfaces are doing again. I've shown
108:52 all these pictures before. There's there's geologist looking at these lower network growth
108:58 inter bedded with floodplains with beautiful it trees. There is an example of
109:05 schematic payments on the left and an of a paley saul from the fan
109:09 the right. And boy, they pretty well. Most of the firm
109:13 solves what we call history calls, means they have an O. Or
109:18 horizon. Iaea peat or coal or shale in general are immature because it's
109:25 very dry. So they're immature soils history calls. They do have horizon
109:32 . So here we've got the the the bi layer which is largely leached
109:38 we have an upper B. And lower B. And then the C
109:41 is the bedrock in this case, is an older crevasse play. That
109:46 that is And floodplain that has been a little bit and cracked. And
109:52 those roots in the kind of see roots in these, in these police
109:57 . So we've got these glade or palace halls. The gray color applies
110:04 wet. We don't see any evidence quality which would be evaporates that you
110:09 see in a dry palace all we abundant roots again, which tells you
110:14 the and the and the roots are preserved carbon. So again the roots
110:19 not particularly liquefied, they're not salaciousness they're certainly not replaced with carbonate.
110:24 get poorly developed, so called pet . These are the structures that formed
110:29 wetting and drying of the soils. get these cracks and you get material
110:33 in the cracks. These are poorly in the ferret, which again is
110:37 of ever wet conditions. Of course get the coals and carbonaceous shales implying
110:43 high organic matter content that again tells in every environment. So there's sort
110:50 an example of what the vegetation looked to produce the coal. Um bought
110:58 sort of had had done his master's on by activation. So he had
111:03 of the bar activation index, which the degree of borrowing by organisms,
111:07 sediments. And so we thought about a slick inside index which is the
111:11 of cracks in the mud that didn't out so well. But he decided
111:16 sort of estimate the degree of which is sort of the degree of
111:20 disruption by roots. So he put a routing index first one to ever
111:24 that. So quite clever and I at this police all here. So
111:29 the crevasse play, it's over land flood plain mud and then it's over
111:33 by this colon pete. And in he put this routing index shows that
111:37 routing increases towards that surface there, represents the period of maximum exposure.
111:43 then essentially we have a little rise the water table and we get the
111:47 developed. Right? So in terms sequence photography, the exposure surface would
111:54 there. Okay. And then that be over land probably by a little
112:00 surface or water table increased surface. could be the landing land would equivalent
112:06 a transgressive surface maybe. So we sort of have a little bit of
112:10 cycle even in these pearly assaults. so here's an example of his measured
112:15 . Obviously it's hard that the the index is zero in the sand stones
112:21 its high typically just below the And in some cases you can see
112:26 sort of this upward increase in the index. The other uh concept that
112:33 put together. So Stacy actually who's professor at at Baylor University worked with
112:40 Greasy. His graduate student was Dave , who now works next on and
112:47 an internship with Exxon. So he's working with Tim Demko and Dave Cleveland
112:51 Exxon. And so he decided to this concept of flu viel aggregation all
112:57 and it flew generational cycles could be floodplain to corvus, to flood,
113:02 flood plain, mud stone, couple comedy capped by a call. Or
113:06 could be a channel filled. These be grouped influential congregational sets. And
113:11 sort of the equivalent of facing successions paris sequences in the non marine
113:17 Okay. And you know, ultimately , the idea is that the stack
113:22 full fledged Floreal sequences. So body of integrated, you know, the
113:30 geology of a crevasse play with a plain, mud stone or lake deposit
113:35 top that gets routed and then it's flamed by a peat swamp deposit.
113:41 , And, and then the cycle and it wrote it wrote it into
113:45 channels that find upwards. And we cycles of channel finding as well.
113:50 would be one flew viel aggregation of . There will be another one
113:56 And so here's an example from mary flavia aggregation of cycles from the will
114:01 formation Wyoming. This is similar to fairest formation that, that this hijack
114:10 , Heller and Ben sheets. Did Cressy function on random avulsion cluster
114:16 Anyway, getting close to finishing So this is the cross section of
114:22 non marine faces along sweetwater wash. got the black hole's correlated, you've
114:28 these pink paras plays and levy And then he got the channels with
114:33 accretion shown with the gray and more sandy cross bedded channel films shown
114:38 the yellow, uh, and and some of the flyby inauguration cycles
114:42 across the whole area. And this not a massive area. So maybe
114:46 forgot what I can't really read the there. A few few kilometers,
114:51 a nice example of the correlation of , channel belts and flew viel.
114:56 cycles. There is the same cross with the uh with routing index and
115:03 can see that those are systematically correlate across the area. That gives you
115:08 eye that the floodplains are pretty And Dave Kennison has done similar work
115:13 his PhD and then we can integrate flotilla generational cycles plus the detailed
115:20 And then we can go ahead and to look at the at the sequences
115:24 systems tracks again. Sorry about the word wrapping here. We've got the
115:31 stance systems tracked representing the incised sand valley fill that goes from transgressive systems
115:39 that culminates in the coal that marks high stands. Okay, so that's
115:44 the high stand here. Sorry, stand. Systems tracked. Transgressive system
115:54 cut by cole and it looks like may be another transcription assistance track
115:59 Then going into another Hiestand systems track and that should be up there.
116:04 TST was here. Yes. So the cross section below where we've got
116:10 sequences and systems tracks and then brody to a wheel diagram of that's
116:18 He discovered that there were 21 fleabag . All cycles Developed in sequence one
116:24 2, nine FAC sets three high sequences suggesting maybe 30,000 years duration.
116:34 since got back and redone the bentonite and looks like it's even faster.
116:41 20,000 to 10,000 duration. So these very high frequency non marine cycles.
116:50 , so that was the original sequence . And then they went ahead and
116:54 identified an additional Hiestand and transgressive systems . So he actually identified some type
117:00 sequences in the upper non marine Ah But so yes, police calls
117:12 and the flu the aggravation cycles, integrates the channel film. Yeah,
117:16 integrated growth, right stacking of illegal as well as correlation of the police
117:22 cycles and the routing index. Okay dan fixed D'Souza and Omar Montes.
117:32 focus was more on on mapping the along sweetwater wash. And the channels
117:38 very scale, some of them very , amalgamated others very small. Then
117:42 the coals and the corvus plays and and levy deposits and in green and
117:49 . What they did is they mapped channels across sweetwater wash. So they
117:54 air crops on one side, their on the other side. And they
117:57 able to track them from one side the other. That allowed them to
118:02 the width of the channel belts based their paley flow directions. And so
118:09 mapped what is it here? 11 and map the wits of them and
118:15 plotted those on the gambling diagram which we talked about. So here's
118:20 on the horizontal horizontal axis and thickness the vertical axis. And it suggested
118:27 these channels are kind of down in delta distributor very uh system.
118:34 again, you know, remember the I asked if you see channels they
118:38 distributed or trunk. And so we've found the trunk channels. Those are
118:43 incised valleys. But in this low to gross floodplain, it looks like
118:47 actually on the delta plane, We do see evidence of large marine
118:51 surfaces. Here we see evidence of transgressive and high stand, and we
118:57 evidence of that, of channel belt that are more compatible with with this
119:05 channels. So, again, another of using these plots of of width
119:10 thickness to to give you an idea where in the system you might be
119:14 in the source of sex system you be. Yes, there's uncertainty
119:18 I mean, you know, it lies within the braided rivers, but
119:22 know these aren't braided uh and with meandering, but they so they could
119:28 meandering, distributor berries. Mhm. in contrast, the fair and valleys
119:33 right within the realm of of of classic valley fills within alluvial Murray in
119:43 up. So we felt pretty good that. Okay, I've got a
119:49 of world sports slides. I'll let guys read, let you read those
119:54 your own time. Okay, so obviously covered a lot, But hopefully
120:08 example reinforces some of the fear I about in the last two uh
120:15 Okay. I think what we'll do is we'll take our lunch break,
120:19 okay. And then uh it's What time you want to come back
120:27 me? Do you wanna do that ? Do you want to do that
120:33 lunch? Yes, let's take a minutes for questions about silence. Come
120:42 take a look for sure. I don't think it works right
120:54 Right, that's right. Whatever is for you. Absolutely. And
121:08 if you've got questions about assignments, can I mean after lunch we'll do
121:12 Deepwater lecture and then we'll spend the of the down assignments. I think
121:19 what we'll do. We can finish if you feel like it. I'm
121:24 feeling pretty good. I wasn't sure had a lot of food, I
121:27 sure how it was going to kind settle, but it's I think I'm
121:31 . It wasn't very well last but I was okay this morning,
121:34 I skip breakfast, didn't have any because I was a bit worried how
121:38 would feel. So okay, I want that. Okay, multiple partisans
121:55 now share. Mhm. Okay, . Right, right now thanks.
123:21 see how do I do this. we go. I just went to
124:29 , so okay go ahead, First threshold. So much truth
124:50 Which yeah thanks. Okay mm I mean yeah, no that's
125:58 I think it's over here probably as as I can make it. I
126:18 where my annotate has gone. I annotate it. It was down
126:24 Oh, but anyway, so I what I would do is I would
126:32 take that and have that truncated by channel if you like for that and
126:37 looks like it might caution upwards so might just take that flooding surface there
126:41 I'll probably just take it into their little thing there and you know,
126:46 it's building up in this younger valley cutting it out right? But I
126:51 over client informed that there here. not quite sure what that surface is
126:58 . So you've got a flooding surface , right? That's going to go
127:01 here. You got a base, haven't drawn your Samson yet for your
127:06 . So I would maybe start drawing sand stones in, right? So
127:15 can draw a shot at the base that funnel Suzanne at the base of
127:19 one. Then maybe that correlates to channel and it goes back to a
127:24 . You know, he got a , it's kind of getting silty.
127:26 good. But I would just drop platform down to there there.
127:36 that's good. Yeah, yeah, of these conflicts might be a little
127:43 too steep, probably won't take marks for it, but you know,
127:46 might might be a little bit, know, there is quantum farms.
127:51 they're more aggressive, sometimes a bit aggressive. Start thinking about drawing some
128:03 like in here that's a bit I think want to put that right
128:06 top of the sand, they're right there, right up there. There
128:19 go, yep. And that's where got a decision point, you take
128:23 down there, take it up to one, Right? So that you
128:27 take that. Yeah, you might that. Yeah. And that's going
128:39 change these correlations here a little Right? So, and I don't
128:46 there's a big platforms here. I that just keeps going there. I
128:50 that's probably pretty flat. I'm not what that line is there, but
128:58 not a season. Right? And sand is very thin. Okay,
129:04 a gamble. Okay. Yeah, there's no line, you know that
129:10 , there's nothing ideological about that line . Right? You can stop the
129:13 surface and then just pinch out that if you think it back steps.
129:32 ? Mhm. Maybe maybe there's a funding surface there, there's one
129:38 so you know, and then you connect up with this stuff here.
129:46 ? Yeah, I think that stuff fairly layer cake at that point.
129:50 you go, I like that better see it is converging right? There
130:06 go. This might correlate with that and end up there could be for
130:25 restaurant they subtly said. Yeah. yeah, the city's population yeah
130:43 Yeah, yeah, yeah, there's stuff going on there again. This
130:59 might go a bit higher so maybe that and just think about that a
131:05 bit, you know, because that's think that's that there this is probably
131:14 there. So I think I don't that this bentonite doesn't truncate like
131:20 these correlate down. Yeah, so think that's where you've got in a
131:24 bit of trouble there and I think still too high. Get rid of
131:29 one here. I don't think that laps which is truncated Then get this
131:37 one. See that surface there is that surface there. Mm hmm.
131:50 , I think, I think you're this too flat. I would erase
131:55 and erase that, erase that one raise this one. Yeah. Now
132:03 this and take it to their like and take it to their Yeah,
132:11 you go. And not feel it . That makes that's I like that
132:29 . No question. Yes, pardon . Yeah, yeah, probably something
132:41 that. Yeah. See in this here it goes to there and that
132:54 thing is that little thing there right . Is there a double it,
133:23 could be about right, yeah, . You know, you're doing a
133:33 job. So just get some shoes in there and uh yeah, that's
133:39 nice job. Other questions. Put something else up with Dennis.
134:37 , very good. Okay, so me, I think we'll take a
134:45
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