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GEOL6380 - Sequence Stratigraphy - Zoom_Bhatta-23
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00:04 Yeah, yeah, yeah. Yeah. Yeah. Okay, so
01:03 got everything open here. I've got chat. I could see the participants
01:09 . I'll just ask Maria to keep eye out for, uh when Joseph
01:15 us. Um, sure. Yeah. Still, I know he's
01:23 the quiz because I've seen his So s I'm going to give a
01:28 . Now, that's kind of what call it a reinforcement lecture. So
01:31 talked about Yeah, flu. Viel graffiti last class. And this
01:38 uh, I don't know, an but goodie Michael at Michael and
01:44 His middle name stands for money. , you know, when you meet
01:48 guy whose middle name is money that gonna be successful, Uh, at
01:55 rate. So Michael was my first master student when I was a young
02:02 in 1998 at the University of Texas Dallas. Kind of scary. Think
02:07 was that long ago. I'm trying remember. I think Michael did his
02:11 had a degree in forestry, and he, uh, decided after years
02:16 the in the landscape business decided that really liked geology because it was a
02:22 of business, which he liked. the money in his middle name,
02:26 . Sort of like the outdoorsy, kind of sign. So he decided
02:31 and he'd done some geology here his degree. So he came back toe
02:36 school. You 2000 did some catch undergraduate classes and then, uh,
02:42 his masters with me, and I to put him on the,
02:47 the book Cliffs section in Utah that visited and never done any work
02:55 And the title of his thesis uh, was braided Rivers of the
03:02 Black Hole Formation, Utah implications for Marine sequence photography. And then we
03:07 a paper in the journal Sentiment Research we called the paper uh, no
03:14 in phobia style across the sequence And if I remember all, I
03:18 put the paper, I'll stick it on the on the Web for you
03:21 to have a look at. So book Cliffs says, as I mentioned
03:26 yesterday, has sort of been a ground for trying to understand the sequence
03:33 fee of non marine and flew via in particular. And if you're driving
03:39 Salt Lake City to price Utah For of you have ever been to that
03:43 of the world, if you work a big oil company, it's sort
03:46 a standard field trip location for But, uh, I remember when
03:51 was a postdoc at at, uh Edmonton, you know, some just
03:59 was a lot of buzz about the cliffs and this guy balls Lee,
04:02 was leading field trips Exxon, were their work and, you know,
04:06 who was anybody like it was desperate go and have a look at these
04:10 because they were really becoming sort of pivotal point for understanding the sequence
04:16 Anyway, if you drive from from to price you you go through the
04:21 gates and there's one side of the gate. They used to be clearly
04:25 the other side of the road, it looked like the gate and they
04:28 that down when they widened the So the gates look gone. But
04:31 castle gates sandstone was named after this of this big fin of cliff of
04:39 . This is all Amalgamated Sandy Channel . Why'd he interpreted as braided stream
04:45 nature and the the council gate is from the underlying Blackhawk. And be
04:51 here. There's a this is actually different cliff, so it looks like
04:54 take a jumps. But it's uh, there's a talus slope
04:57 cliff, and then you and then bit of parallax going on there.
05:01 this is a relatively continuous, continuous surface, at least over the limit
05:06 the outcrops, and it separates a forming a stack of amalgamated multistory
05:13 Channel fills channel belts from a muddy unit that contains, uh, eyes
05:19 flew. Deal, um, Onda between the floodplain dominated money Blackhawk formation
05:28 the cliff forming castigate formation was taken the excellent Research group is a major
05:35 sequence boundary. Now, if we around, we see this because this
05:40 on just on the other side of road and when they widen the roadway
05:47 you could see the base of the up there, you see these beautiful
05:52 units, these air coal bearing floodplain . But I think you could see
05:56 meandering channels in the road behind you that just highlights the erosion. I'll
06:01 the base, the channels and then accretion betting in those channels. And
06:07 may you may recognize this channel also this was perhaps the channel I used
06:12 , uh, as a guide for second, with the diagram just illustrating
06:16 geometry of a meandering channel. The is, I put your with the
06:20 . Incised valley. Where is Is, uh, sitting on top
06:25 a coal on some crevasse splay units . Now, if we go about
06:31 miles to the south and these air these rocks are a little bit
06:36 So this'd say this is a campaign succession. And these are Theron.
06:42 . But they showed exactly same Graphic pattern, beautiful slope forming.
06:48 via units of the John Henry member . That's a floodplain and channel dominated
06:53 . I think you can see a there. E don't know if you
06:59 the pointer. There is a channel . They're coming up there is the
07:06 of the channel. Okay. And also you can see a channel
07:10 and it kind of probably comes up . Uh, there's also a big
07:14 here that comes down. Okay, back up again. There it
07:19 There again, This, um And here is this series of cliffs
07:24 are behind each other. And, , this upper unit here is the
07:28 tank member on that. That's a Amalgamated through the channels, you can
07:33 the integral Channel store. There's the can even see some of the creation
07:37 . So you sort of get a for the scale of the individual channel
07:41 elements that build up the vertical And even here in the background,
07:46 can see peace. Um, some betting so that contact has taken as
07:52 as a sequence boundary. And this this was Keith families PhD study
07:58 So Keith Channel, you noticed the thing that the Exxon group did,
08:03 is that you see these transitions from net to gross floodplain dominated, flew
08:07 units to flu units that consists of amalgamated channel belts, overlaying a
08:14 irrational surface that was widely interpreted as sequence boundary, and probably and incised
08:22 . And so it was observations like that led to the development of the
08:26 McCabe sequence photography model, where you a low net to gross Hiestand fluid
08:32 with isolated channel belts so low net gross Hiestand units with isolated channel
08:44 Oh, Verlaine by cliff cliffs of stones with Amalgamated Channel belts, Cliffs
08:51 sand stones with amalgamate channel belts with of erosion, I'll scour the base
08:57 as the base of the valley. , obviously, this outcrop doesn't show
09:01 nice U shaped valley coming up. the assumption is that the scale of
09:05 is bigger than the scale of the on. For better. For one
09:10 the, you know, on this here, it simply says the scale
09:13 one to tens of kilometers. So , if if the valley scour scour
09:18 low angle or is broad, it be a deepens you want. But
09:23 it's if the width of the values of kilometers, you know you're not
09:27 to see the valley edge on a outcrop like this. So the trick
09:30 step is to hunt around the crop and see if you can find that
09:34 edge. Okay. One of the with these big regional studies by Mackay
09:41 , Van Wagoner's that is that they to really find the value is there
09:45 no doubt that they could see the in stacking pattern. There's no doubt
09:48 they could see scour at the base the amount of mated versus Isolate Flavio
09:54 , but the Valley edges were perhaps little bit less well documented than I
09:58 have liked. Um, but that to the idea that there was a
10:04 change influential style from Amalgamated flu viel belts to to isolated channel belts and
10:12 examinations of the isolated channel about showed predominance of point bars associated with the
10:17 Rivers, Andi and the Amalgamated Nature the of the Valley fills push them
10:26 an interpretation as braided channels. now, um and so then the
10:35 idea was that the sequence boundaries defined the change from meandering below to braid
10:40 above that became a bit of thes of theory in sequence strategy, graphic
10:48 . We all know our head and , Well, that's good, you
10:50 ? And then I went through the explicitly. Last class eso I'll just
10:55 you that you know the low stand stones and the castle gate were interpreted
11:01 directly interpreted as deposits of braided so multistory, amalgamated stand dominated units
11:09 braided streams. Interestingly, in the , all always shows a crease in
11:16 direction. Now it's not clear if downstream accretion or lateral accretion or
11:21 but it's interesting that that the diagram show any bidirectional accretion. We'll come
11:27 to that in just a little In contrast, the Hiestand Systems tracks
11:33 transgressive systems tracks were interpreted be deposited single story sound stones that were
11:40 So curiosity and, of course, point bars. And that, of
11:44 , uh, implies or assumes that are the deposits of meandering streams.
11:51 , okay. And of course, know, we began our discussion of
11:56 sequence photography by pointing out that you , the traditional models for Flavius
12:02 Before there was sequence, photography suggested mug dominated, uh, flu viel
12:09 were deposited by strongly meandering streams and flu viel sand stones were deposited by
12:15 streams, and never the twain shall . Okay, um, now,
12:19 I began, a couple of things in 1998 19. Sorry,
12:28 I began working with Brian Willis at Bureau of Economic Geology. We were
12:34 scientists there together for a couple of , and Brian was a PhD.
12:39 done his PhD with John Bridge, John was. John was not very
12:42 about the scent of rated versus meandering Economy said, Look, you
12:46 Fallujah systems more complicated than that. know, Net to Gross is controlled
12:50 things like migration rate, avulsion subsidence rate, you know. And
12:55 doesn't have any obvious relationship to this sort of tired dichotomy of braided versus
13:01 . That was the sort of the lluvia model dogma, you know,
13:06 the fifties until until the early Uh, and then when I became
13:12 professor, I noticed that the textbooks everybody was using, you know,
13:17 as Sand Boggs and the late Sam and Gary Nichols, who was a
13:22 of mine, you know, sort emphasized, you know those books.
13:26 know, once you got the flu chapter would say they were braided
13:29 their meandering rivers, and it was about brilliant versus meandering rivers.
13:34 you know, the expert community kind said Well, that that's an
13:39 And, you know, maybe we sort of rethink the idea that the
13:43 thing that's that's necessary and sufficient to flu you'll systems is whether they're braided
13:48 meandering them. You know, I I hit that theme pretty hard last
13:55 and again, I'm just just giving another reminder here. You know when
13:58 start seeing the same diagram 23 No, it's probably an important
14:03 Thio pay attention to as we move our last day together and and make
14:09 that you're prepared for the final on . And so what this diagram explains
14:15 I went through last class, is the net to gross eyes controlled by
14:21 like the rate of channel migration and frequency of revulsion and the overall
14:27 uh, aggregation of the floodplain on those features aren't aren't necessarily obviously related
14:34 whether the rivers meandering abraded. In , we showed that that strongly Latin
14:42 accreting sand belts are commonly produced by rivers, land would of the backwater
14:49 the rivers don't feel the rise and of sea level as a result of
14:54 sea level changes, tides or storms , but once you get into the
14:58 back water, uh, migration tends be inhibited. Ah, vote is
15:04 in the backwater, resulting in a lower channel about with the depth ratio
15:11 DSO, Mike Bloom would say, , actually, you know the net
15:14 Gross is controlled by whether or not in the lower back. Water or
15:18 of the backwater has nothing to do stream style. So a meandering stream
15:25 give this kind of channel geometry or kind of jet channel geometry depending on
15:30 it is in the backwater. That That was kind of a message that
15:33 gave you yesterday. And then let's said, Well, you know,
15:37 could also get, you know, of channels. You know, if
15:41 got a function clusters, you and that's and that's on. That's
15:46 consequence of avulsion on dso. You what I should have said is,
15:50 1993 Bristowe and Best said, we may we need to we need
15:55 pay more attention to what controls channel and what controls avulsion. That's been
16:00 big focus of research since then. the newer models for fluids. Photography
16:05 are coming out now are pointing out you know that the controls on
16:10 on avulsion of things like backwater effects avulsion clusters and and have no obvious
16:18 to the simplistic, meandering versus So again, that's just sort of
16:23 , You know where we went yesterday the lectures on flu deal,
16:28 strategic fee. So the question then is given that there is that there's
16:34 about, you know, and and of the interpretations of flu viel successions
16:40 braided is not dependent on analysis of actual channel Phil themselves. It's the
16:47 observation off the high net to So most geologists who trained in the
16:52 and eighties if they see a big stack of fluid in Nepal, it's
16:56 assume it's braided rather than demonstrate its . Okay, on, I'll talk
17:03 little bit later. I'll give you the critical criteria that's required to distinguish
17:08 or not a river is braided or okay, and whether or not that
17:12 anything to do with sequence photography, , and of course, you
17:19 the interpretation of rivers braider meandering fundamentally you have to know what the platform
17:25 . And the question is is if you have is a well log through
17:28 feels photography. How could you possibly what the plan viewers you consider?
17:33 know what? You know what the to gross is because the well law
17:36 will give you the percent of channel versus floodplain intersected by the well.
17:41 , of course, if it's mostly about, you can use,
17:46 this model say, Oh, it's channel belt must be graded. But
17:49 I'm trying to tell you is that that's the wrong model, or
17:53 if you're well, log is mostly , mud stones and a few channel
17:57 , because they must be me and . But again, you know,
18:00 models have not really stood the test time. Okay, now I want
18:07 get a little bit thio the the of the black hole Capital Gate.
18:17 , um, one of the things that that the Exxon Group did is
18:23 would they would see these, sequence boundaries. They would rise them
18:28 , rise them up, and they tip them out on top of the
18:31 . Paris sequences, so they tipped out. So that's the end of
18:35 sequence. Stops there. And you , this is the grassy Hiestand sequence
18:42 . This is the desert low And so obviously the high stand is
18:46 than low stand, so that that sequence party tips out, there's
18:51 you know, like there should be big you know, in my
18:56 what that's worth. You know, should be. There should be a
19:01 form, a nice low stand delta by that incised valley. You
19:04 even if there's a bypass surface there isn't. Okay, so a
19:10 consequences That interpretation that led John back the hypothesize that the rivers in the
19:18 gate dry it out in a terminal fan before they ever reached the
19:23 So there is the shoreline and there's end of the river. So he
19:28 that the Catholic ate the Cascade River I'm not even sure what this
19:33 This to me looks like a flowing . There's no scale on here.
19:39 is hundreds of kilometers. This this sort of imply that the river is
19:44 you know, 50 kilometers wide there's no such thing on planet Earth,
19:49 that's a different story. Um, is the area that they studied the
19:53 . So you know, there's a boundary and there's the tip out
19:57 Then they and then they suggested that was some shallow lakes and swamps on
20:01 low stand shoreline that really didn't have sediment associated with it. So sort
20:05 about it was sort of set up shoreline, and they and they hypothesized
20:09 the that that that the castigate rivers , uh, terminated in the middle
20:16 the sort of in the middle of floodplain. Now, I remember John
20:22 Wagoner presenting a talk on this at PG some years ago. So this
20:27 sort of a nanite dote because I his paper several times and he was
20:32 smart enough not to put his verbal into writing because he knew that people
20:37 be critical of it. But I him. John was a very
20:41 very colorful by extremely gifted presenter. , he was just talking at the
20:46 of his lungs about about his idea the that the Black Hawk,
20:51 and and castigate recorded a massive changing in which the Black Hawk was a
20:59 climate on the castle gate was an climate, and as a consequence from
21:06 change from human to arid, he that the water in the castigate rivers
21:11 of evaporated before it ever got a to get to D. C.
21:17 perhaps some of the water also infiltrated the poorest underlying rocks of the of
21:23 Black Hawk. Okay, so he the change in flu. You'll
21:28 I'll, uh, to be consequence the of the transition from the Blackhawk
21:34 sort of more traditional delta system, which the rivers reach the sea to
21:40 arid system in which the river is lost their water and sort of appeared
21:45 on a vast sort of coastal Now he talks about shallow lakes and
21:52 , so that that sounds a bit to me. But nevertheless, you
21:55 , he had this idea that it a big climate change. Okay,
21:59 course. He You know, of , that the Black Hawk is well
22:04 for all the coals that our mind you know, have not time to
22:09 into the strategic graffiti coal. But preservation of Coles requires wetland, so
22:14 typically indicate a human environment with lots subsidence. So, in addition,
22:22 course, the Blackhawk systems were interpreted . The castle gate is braided.
22:28 in addition, of course, you , the council Gate Rivers never got
22:33 see. And so the other assumption , Well, they probably couldn't have
22:37 much mud. Right now, we got time to talk about a,
22:42 know, to give you a course flu viel settlement ology. How many
22:47 you have never heard of of a a suspended load versus a bed load
22:53 building? Pray talk about that. . Okay, now what's interesting is
22:57 you go back and look at Data showing was the flu 70 ologists
23:03 they came up with the idea that are suspended load rivers and bed load
23:08 and the bed load rivers carry 85% load in shams classifications and the suspended
23:16 rivers carry 95% suspended. Lower the load rivers of some carry 15% bed
23:25 on the suspended load, river was 5% bed load, so There's a
23:30 of three difference in the amount of load that abed load reverse suspended load
23:34 carries. But there's only about a difference in the amount of suspended
23:39 So the message is that most rivers of the time when they're in
23:44 are dominated by their suspended load. , on rivers carry between 5 to
23:50 of bed load. So there really no such thing as a river that
23:55 has no suspended load that will be blue water river. And that would
23:58 very, very rare nature. And in order to prefer. And we
24:04 that the, you know, way know that the you know these,
24:12 know, if you sort of think source to think, Yes, you've
24:15 sandy valleys here. You've got Sandy there. But what about this man
24:20 ? You've got thousands of feet of , all of which is derived from
24:24 erosion of the land and deposited in rotation Seaway. So according to Van
24:29 hypothesis, somehow that castigate river the supply suddenly disappeared. That means that
24:36 , you know, if the Blackhawk was a suspended river uh, the
24:42 Wagoner climate hypothesis would require that the went from carrying 90% suspended load to
24:48 no suspended load. Yes. So of the eso, this model you
24:53 as well drawn and is interesting as as it looks, has some pretty
24:58 concerns. Now, as as it on the diagram, you know,
25:04 the work on the on the Black was done from the middle part of
25:08 of the flu ville system out towards deposition ledge. And no one had
25:12 done any work in the more proximal . Um, that Wagner interpreted these
25:20 as as mega fans. And I , Well, let's look at the
25:23 end of the of the castle gate see if it has anything resembling a
25:28 mega fan. And let's also have more careful look at the flu in
25:33 style of the Black Hawk at the proximal and and see what that looks
25:38 . Okay. Uh huh. So just let's just think about this a
25:45 bit, okay? So let's kind add up our our hypotheses and think
25:51 the consequences. Okay. So according the theory, according Toe fan Magnus
25:59 . The Blackhawk is meandering, which that there's fewer rivers and more
26:05 It's also more human, which means there's more water. Okay, the
26:11 gate is interpreted a greater river, means which means a larger number of
26:17 active streams. And according to the , the climate was more area,
26:22 less water. Okay, so let's this through, right? So which
26:28 should be deeper? The Black Hawk the Council gate Black Hawk has
26:34 uh, fewer rivers and more Cascade has more rivers and less
26:40 So which rivers should be bigger? can type the response if you want
26:46 see if anyone wants toe. I should be bigger. Exactly.
26:51 So the hypothesis is the castle gate have a larger number of wider and
26:58 channels. Okay, on the black Hawk should have a fewer number of
27:03 and deeper channels. Okay, in addition, the scales of bars
27:10 bed forms, such as such uh, cross beds on and another
27:16 indicators should be very different. So if you've done built to praise
27:21 , you know that the size and of bed forms and bars scaled to
27:25 size of the river so bigger, rivers have bigger dunes. And that
27:29 big cross beds and bigger rivers have bars on. All of those should
27:34 evident by looking at the rocks, , and it's remarkable how many papers
27:41 were published on both the Blackhawk and , with no basic work done on
27:49 on the on the faces, architectures paleo hydraulic reconstructions of these ancient river
27:57 and have to work with Broad Willis being around John Bridge, I
28:00 Well, I know how to do work So let's actually test this hypothesis
28:04 looking at the rocks and more detailed had been attempted before. So just
28:10 remind us we're in the Cretaceous Interior . It's a wrap margin of the
28:15 margins. There are thousands of Columbus in the Arctic and Gulf of
28:20 We're gonna stuck in the middle of facing unopened ocean with a very deep
28:26 ramp margin that slopes towards the center the base of Okay, okay,
28:32 a general in general, The depositions you know, is broadly speaking,
28:37 West to East. Although you you'll that there is a big curve in
28:42 shoreline. That's the so called Utah , Uh, in the area of
28:47 . Okay. Uh huh. And know what is this diagram? Which
28:55 is this diagram? I'm not gonna you to memorize the steps, by
28:59 way, but just see if you my my methods paid my methods of
29:05 correct. Daniel got it right. step one. Get the big
29:08 right? Yeah. So we always with that. Now, the book
29:13 is also a place where there has lots of studies that have been
29:20 Okay. And, uh, let just spend a minute on that.
29:26 So these represent, uh, the of the lift? Those photography's okay
29:34 these. These represent the sequence. okay. And I want to look
29:39 these little returns a bit. There is the Blackhawk formation.
29:46 And it's broken up into a lower member. A middle shale member,
29:50 sandstone member. I'm not remember on what? What's the boundary between these
30:01 ? Anybody? What do you think boundaries are? Wheeler? Arbitrary
30:09 Arbitrary verdict. Cutoffs. Exactly. . Yeah, you got that
30:13 All right. So, clearly, whole book was Was was a need
30:17 a reevaluation. Okay, Eso that to sort of sequence photography version
30:24 Which was the Van Wagoner interpretation, know, breaking up the the So
30:32 the matter of shale. You've got desert member at the castle gates sandstone
30:41 , then to the right here, the medical shea on the castle gates
30:45 , the formation names change change. comes a vertical cut off their basically
30:49 of in or ignoring those and, know, coronary the flooding service that
30:54 Paris sequences on the sequence boundaries that the incised valleys from the from the
31:00 the marine woods. The difficulty is they do have this scenario where the
31:08 the valleys tip out against and then they don't seem to feed anything.
31:14 a bit of a problem, So they showed modern forms, but
31:17 never allow the erosion surfaces. Thio right. So, you know,
31:23 a situation where there. So that's out. Perhaps that sequence Spanish ships
31:27 be there. And so there's some with those correlations. And so,
31:35 , uh, when they published, Van Wagner published his paper, you
31:40 , he showed to a different interpretations the castle castigate Blackhawk booklets photography.
31:47 in the upper one, he tips the sequence boundary on top of the
31:51 stand. Okay? Which means that the deltas, Aaron, the high
31:56 and all that fluid was in the stand. And so you have low
31:59 that feed nothing, uh, that into Delta's that were fed by
32:04 Right. So the rivers that fed high stance on them to never preserved
32:09 is that I would have imagined might been fed by these rivers are never
32:14 , and he basically shows thes contacts erosion surfaces. Then he shows the
32:21 diagram that shows an incision that then that ends and passes a nuclear
32:28 Conformity. Okay, an incision that into a core relative. Conformity.
32:33 now he has this river feeding all stuff here. Now I think that's
32:38 more reasonable interpretation. What that says got sequence boundaries and coral conformity.
32:43 thinking up the river and it's forced delta. Okay, Now, for
32:49 reason, John bandwagon refers to that a little security interpretation on the above
32:55 a sequence strata graphic interpretation, I argue that these air different sequence strata
33:00 interpretations of the same rocks. And this is a more simple sequence.
33:05 graphic interpretation that puts all the flu a little faces into one sequence on
33:10 the Delta little faces into the second or systems tracked on this diagram.
33:17 faces are put into different sequences in sequences. I personally favor this interpretation
33:24 disfavor that one John Batman, your , this one and show this is
33:28 incorrect interpretation. But, um, think the ah much more recent work
33:38 a colleague of mine, Simon Patterson the University of Grand Man tell
33:42 But I was gonna put a slide morning because it's it's like I was
33:45 , Yeah, I should put that and he's gone back and redone.
33:48 this photography and his correlations have corroborated lower one. So So this one
33:54 not correct anyway. And of you know, the interesting thing is
33:59 in the so called excellent sequence different little faces, a largely paste
34:04 in different sequences uh, whereas in example, different with the faces or
34:11 in the same sequence. So yeah, this is this should never
34:15 been called little photography. Thes We're just different secret strategy graphic hypotheses
34:20 the same rocks. Okay, so a very schematic depiction of the of
34:30 started graffiti of the of the of Black Hawk Castle Gay. Okay.
34:37 , uh, in this area you know, there's Bosch photography in
34:41 buck tongue and all of these marine sequences the desert grassy Sunnyside.
34:48 actually, a lot of these things sequences and have multiple Paris sequence within
34:52 , you know? But there's marine below here. Marine fossils about
34:56 There's indications that there's a hiatus Okay, And now here, of
35:02 , you've got a non marine normally, Blackhawk overlay, non marine
35:06 . So it's a little harder to what the age of these non marine
35:11 Marine units are because it's not as bar superior has been done on the
35:15 Marine faces is the marine faces and of the previous studies of the cascading
35:20 Hawk are kind of outlined by that seven So what I thought was
35:25 let's go to approximately and where No done the work and see if the
35:30 based on the distant land could be by an examination of the proximal.
35:35 course, this contact is why they as a krone strata graphic sequence
35:40 You know, and I spent a of time last July showing you that
35:44 flew. The units can have very , uh, dia grenades on the
35:49 between, you know, Amalgamated flew unit and less amalgamated stuff below.
35:56 more complicated because of the preservation of , which are impossible to date.
36:01 , having said that, you the the interpretation was that there seemed
36:05 be certainly everywhere you look, there's erosion. So you know, it
36:10 . If everyone, if everywhere you the contact between the castle gate and
36:15 Blackhawk, it's a scour surface then the assumption is that a through
36:19 single scout surface, hence regional There's interpretation of value scale incision.
36:25 it isn't clear that there's a lot relief on the incision, we could
36:29 about the evidence for that, there is evidence of the basin with
36:35 and faces and, of course, big part of the interpretation that has
36:39 influential architecture from meandering students below two streams above. So here's the area
36:48 we were. So we're here in ESO. Previous studies were basically from
36:53 all the way out to Grand with very little, very little work
36:57 along the Wasatch Plateau. Part of reason is that the council bait is
37:01 ft up in the air. But you drive on I 70 there's some
37:06 , set of normal faults that bring that surgery right down the road in
37:11 that are quite easily accessible. Andi in the day, I was doing
37:19 trips to Atlantic Richfield Company, a research geologist, and I was asked
37:24 start leading free leading field trips to . I've been there on field trips
37:30 Gus Gustafson, who I worked with BP Alaska, and Gus took me
37:36 the very first, my very first to the book Cliffs. Uh,
37:40 year I got to our co in and you know, theater crops blew
37:47 socks off and then, you with within a few years after having
37:52 on field trips. I was being to the field for the company.
37:54 never worked there, but, you know, George all look pretty
37:57 to me. So I said, , So you know, myself and
38:00 Morris and Harry, any postman Tear my boss Bob Project. We went
38:04 around Utah, you know, driving crazy in our four wheel drives.
38:09 I was whizzing up by 70 going you know, 100 kilometers an hour
38:12 more. I said, Wow, Blackhawk castigates right there at the
38:17 So I found a way to get the highway and said, Wow,
38:20 is pretty outcrop and started eating field there. And then when I left
38:25 and became an academic, I You know, I am sick and
38:29 of leading field trips to that outcrop any measure sections. So,
38:34 at the very first field camp I talked for UT Dallas about all the
38:39 to this outcrop, and Michael Adams doing the undergraduate force and and the
38:44 methods because he had to do some , I said. Now Michael Adams
38:48 going to do his master's thesis Why don't we all have him out
38:51 a series of sections of the And then he's going to do the
38:55 faces, architectures and so eso so so that was basically the set up
39:01 doing the project. Now what's nice that the black hole castigate contact is
39:07 along a dip and strike cliff There's II 70 and you could see
39:12 a dirt road that comes in. was able to find the access to
39:15 road we parked right here, you know, we were minutes from
39:18 after all. So this is what outcrops I was driving by look
39:22 Okay. And here you can see Blackhawk, you know, it's it's
39:27 exposed, but, you know, can see clear evidence of channel
39:31 It's kind of coming and going And then here's the council gate that
39:35 exactly like the Council gate, 80 north, that Price County Nice big
39:40 of Amalgamated Sand Stones with what looks all all intents and purposes like a
39:45 razor sharp contact. So a little of work had been done in Salon
39:53 canyon. This was worked on a thesis by Black at Brigham Young
40:00 And I probably wouldn't give us much than kind of a B minus for
40:05 betting diagram. But, you there is some evidence of mounded
40:10 you know, uh, scours mounds see them here. You know that
40:16 no evidence of consistent downstream or lateral , so he interpret business of grated
40:22 on the basis of a lack of bars observed in the outcrops. So
40:30 what the Blackhawk looks like. the the castle gate. So we
40:37 large um ah, really large four . There is ah ah Dave MacDonald
40:48 scale. He's used to head up British Antarctic Geological Survey, and now
40:52 a senior professor of the University of . There is my buddy James
40:58 uh, acknowledges par excellence, and is a classic unit bar. So
41:03 is a unit bar in a braided , and then these air maybe a
41:08 bit hard to see. But this doing scale. Cross bedded sand stones
41:13 represent a compound compound bar filled with scale crossbred. And this makes a
41:20 this single story in a multistory sandstone , and you can see the individual
41:26 marked by the sharp based finding up cycles. We have 123456 vertically stacked
41:35 in this outcrop in this council Alcohol mhm, um, so back
41:41 the study that we did on that was actually on the other side of
41:45 70 another crop that we did a bit of work on for some other
41:51 on. So what we have And here's the Perry current directions.
41:54 we have a cliff that's oriented parallel the flow on a cliff Origin perpendicular
41:59 . This is critical because thes these oriented at variable directions to paleo flow
42:05 are the kind of of cliff geometries you need to look at in order
42:11 resolve the nature of the bars that that build a river and that and
42:17 is required to understand platform geometry off river. And I mean, I'll
42:23 about this a little more in the lecture. When I went, I'll
42:26 into the fair movement. So Michael included 24 major sections with the usual
42:34 grain size seven matches, structures and currents. He did four across
42:40 so two of them were sort of he called regional. Now it's a
42:43 area, but this was sort of entire channel about and then, within
42:46 individual channel about. He interpreted the architecture of the dunes and the bars
42:52 order to try and decipher the You'll style. In addition, we
42:58 a few thin selections to compare the Gate and the Black Hawk.
43:07 so this was the photograph of the the outcrop in which the you could
43:14 some pretty continuous channel belts in the Hawk, okay, separated by
43:18 So channel belt into bed with There's the contact with the castle
43:24 And although it's a little hard to , this is all all continuous sandstone
43:29 . Now you can see this very , but another thing we observed is
43:33 the castigate has kind of a creamy of white color to it. On
43:40 Blackhawks, channels have amore grave color them. So there was a color
43:45 between the Black Hawk and the Castle , and I'll show you in just
43:48 minute that that's reflective of the different of the sand stones, the the
43:55 gates, of course, Maronites on black. The Black Hawk is more
44:01 music and character. And so that the the sort of large scale flip
44:07 . Zack showed a Siris of Amalgamated Banks in the castle gate. And
44:13 showed you some details of the castle flew via channel style. In the
44:17 slides, they overload overload the lower to gross Blackhawk. The comprises channel
44:23 , inter bedded with Muslims. the Blackhawk Channel bounce on the scale
44:28 5.5 years thick, okay? uh, and I and then we'll
44:33 a look at the channel belt thickness the castle gate a little bit.
44:38 , so it's right here. So thickness of individual channel stories and the
44:43 gate looked like about 4 to 7 thick on the block off their 5
44:47 8 m thick. Okay, so channel story thickness, which is a
44:51 for channel death. It's pretty similar two systems. That's the first thing
44:55 notice. Let me go around the . Flow is not coming towards
45:01 and we can see that this middle belt and the Black Hawk pitches out
45:05 here. The lower one kind of on going. You can even start
45:10 see some geometry within it. on, then. The castigate is
45:14 platform unit about. I think you see the castigate sand stones have a
45:19 brighter color than the Black Hawk, is a bit more gray.
45:24 once again, the Black Hawk formation bouts or some between about 5 to
45:29 m thick on the cascade, is your unit. Ah, 100 m
45:34 . But it consists of stories that that that are about the same
45:40 There is just some photographs of So the Blackhawk consists of floodplain mud
45:46 , Richard Coles and plant material. on again the preservation of all this
45:52 plant material eyes proof, positive of relatively human climate. And the fact
45:58 you've got great fairly Saul's again is of a human climate. So the
46:04 that the Blackhawk rivers were deposited the climate is corroborate, corroborated by the
46:09 of the flood plains. The channel have erosive razor sharp bases, and
46:16 consist of nice dune scale cross bedded stones that you can kind of see
46:20 the photograph here. And we could a feeling for the thickness of the
46:25 of the cross bed sets. And cross bed thickness can be used
46:35 estimate chairman depth flow depth. here's an example of some of the
46:43 splay facing. So this is a example of climbing current rippled sandstone in
46:48 crevasse play and you can see the you see little ripples here. So
46:53 scale bed forms climbing. There's the sets. Beautiful climbing ripples is my
46:58 for scale. And, uh, don't have a photograph, but but
47:03 crevasse plays every once in a You see beautiful dinosaur footprints associated with
47:10 these canvas plays and came that there dinosaurs walking around the surface, feeding
47:14 the vegetation. Yeah, the fence . Differences were quite market so that
47:23 castle gates sandstone is a court. night that we see here is a
47:26 crystal. Pretty good porosity. But Black Hawk is filled with rock
47:32 Okay, What's interesting is 25% of Blackhawk consists of carbonate fragments. The
47:39 gate is a court paranoid. Now, I want you to go
47:45 to your sort of weathering one on . Right? If you have a
47:49 environment, right, walked rocks are to be the first to be weathered
47:58 . I was first. Yeah. Parliament. You have water. You
48:08 limestone. What does the water The limestone. Yeah. Anybody.
48:15 could see your mouth moving, but hear you. You could, hydraulic
48:18 of the calcium carbonate and dissolve Exactly. Right. Remember?
48:25 Hypothesis is the Black Hawk was and yet it has, uh It
48:31 unstable fragments, things that shouldn't What in human environment. That's kind
48:38 strange. If you have a human , you would expect the carbonates to
48:42 dissolved. Prolific airlines to be all to clay. You'd expect it in
48:47 more human environment you might get a forts rich. And as Daniel
48:51 maybe the fellas bars would be less . Um, uh, but in
48:57 , we see the opposite. The gate, which is supposed to the
49:00 has nothing but course you go. . That's kind of weird. So
49:03 the the composition of the sound stones seem to be completely opposite of what
49:08 might expect for human versus area Okay, Now, let's take a
49:16 so stretch break here just to make your brain's working. So this is
49:22 of a really critical slide. Uh . Not so much for sequence
49:29 but but critical to understand, faces architectural analysis on how that allows
49:38 to understand Floreal stunt. Okay, in this diagram here we have a
49:46 . Okay, It's bank attached, it's creating in that direction.
49:49 so that would be an example of point bar. Okay. The bar
49:55 consist of doom scale. Cross Okay. And if that's coming towards
49:59 , it might look like trough across here. Maybe there being ripples on
50:03 . Okay, so the cross bedding the bar represents the smaller scale architectural
50:11 . Okay. The cross stratification or traitor bed sets group To make these
50:18 scale accretions sets that are formed by bars, the bars migrate to fill
50:24 channel as the channel is migrating in direction. That, of course,
50:30 makes the channel belt on, of , but the channel feels amalgamate to
50:37 the larger channels we have the bars the channels that build channel belts.
50:42 , now, of course, what interested in doing is seeing whether or
50:45 based on analysis of the faces, , the channel, about Phil,
50:50 could determine whether we have banked point bars or mid channel braid
50:55 So that's that's the number of That's the core point that's required to
51:02 whether a river is berated or Andrew, it has nothing to do
51:06 Net two grows. It has everything do with the geometry of the bars
51:10 the channel. Okay, so, , so here's the example of the
51:19 parallel. So flows in that direction the Blackhawk. Okay, so there's
51:24 photograph. Probably can't see much in photograph. This is Michael Adams,
51:30 diagram betting diagram of the cliff architectures he did this in the field so
51:36 could see all the detail. And have, uh, intra bar A
51:41 services, which is the blue A tent bar. Top services,
51:46 would be to the yellow lines. . The channel base, which is
51:50 red line. Okay. And then top of the channel through, which
51:54 the green line on. It's pretty that in the flow parallel direction you've
51:59 downstream accretion. Okay, Uh, you've also got thes thes little scours
52:07 little scour pits here. Okay, have local scours. Okay. On
52:13 air, probably consulate scours around the . Okay, Now, the question
52:19 , the real question is, what this look like in the strike?
52:22 view. So here's the strike parallel of that channel that shows the pinch
52:28 . Okay? And again, there a photograph of the cliff. There's
52:32 line betting diagram of the cliff And then there's the line. The
52:37 diagram exploded for you, and it's clear that what you don't have is
52:43 single set off creating surfaces. you have is mounted bars that show
52:50 directional down lap onto the floor of scour service mounted bar forms that accrete
52:58 more than one direction. So there's braid bar. There is a braid
53:04 . There's a braid bar. There a brave bar. There's a brain
53:09 . So it was immediately obvious to . Now this down arrow, basic
53:15 down means flow towards you. Up flow away, away from you and
53:20 floated left is for the right, a right hours floating right left our
53:26 left. So that's the convention. you're looking at cliffs as to how
53:29 draw the inference, you can also them with dollars towards you or a
53:34 undock will be flow away from you that those of the conventions used.
53:38 So It's really critical when you're making betting diagrams that you interpret the betting
53:42 with respect to the petticoats and you it. Zits. Detailed, painstaking
53:52 . You can't just go and look the net to gross to say,
53:54 , it's great. You have to at the internal geometry of the betting
53:57 er toe, actually determine when the is greater, too meandering in cross
54:02 views. And it's almost impossible to this analysis with a well longer
54:08 So I would argue that it's almost to know whether the river is greater
54:12 meandering. If you have coordinates very difficult and you can't use the
54:16 growth. So this is, diagram again, another important diagram to
54:23 you understand that the thinking process on left. We have examples of a
54:29 meandering river, so a bag of point bar that's moving in that
54:34 That's in contrast to a braided river you get a bar in which you
54:38 so that you have difference difference. , I'm kind of giving you a
54:48 lesson in and Rivers here. This all stuff that you probably would have
54:54 to build a brace class. And , when the when the flow comes
54:58 that produces a confluence take Oh so and typically when the when the
55:10 the flow comes back together again, get a little scarab pit that's called
55:14 Continent scour. And that's what, , that's what these things are.
55:23 there. The consulate scours, but threads on a braided bar come together
55:28 make a little scarab it that typically in with the steep prospect. I
55:33 a PhD student in an entire PhD that topic, and so on.
55:39 then and then there is no A simple, greatest stream with a
55:43 braid bar and a compound braided stream multiple braided bars. Okay, with
55:49 difference and conflict zones and you could the geometry is quite clear. You
55:53 these mounded ah bar forms that show directional, down, lap or side
55:59 inflow, uh, perpendicular views, it's pretty clear that the Castle gate
56:05 like this. It does not look a meandering stream. So everybody in
56:10 dog interpreted the Blackhawks meandering for the reason that it's low net to gross
56:16 any really attention paid to the barging . So we were the first folks
56:20 go and actually spend any time looking the bar geometry on. We show
56:26 evidence of Breitbart's and more than one . And so this is the paleo
56:31 Reconstruction Block Dr Block diagram for uh for for for this time periods
56:38 Z that sort of braid bars. that shows the drama trip for the
56:47 set. And then the upper diagram the geometry for the upper set.
56:51 Michael could have drawn, you a diagram that the set and so
56:55 so forth. So quite a complicated of bars shifting left to right,
56:59 to left, with no coherent organization , a classic rate and strength.
57:08 , if you have that if you that point bar that's in the middle
57:12 the dye influence confluence, would that downstream? Because you get a a
57:19 flow at the confluence point where you have some dropping in bed alone
57:25 you know, brave bars. So know bars can either either expand laterally
57:30 translate downstream right on that sometimes called with sweep, sweep, downstream swings
57:38 . That's what the deepwater guys Flu, flu, beall sentiment ologists
57:42 about lateral expansion of a bar or migration. Okay, Andrew Mile likes
57:49 refer Thio downstream of creation vs laterally okay or or lateral expansion versus downstream
58:00 . So let's get a lot of lot of jargon and terminology. So
58:04 , What? You're sitting with the migration of bars with the development of
58:09 confluence galleries. Exactly right on that these bars gradually migrating downstream. So
58:16 get a confident scour and then the fills that scour, right? And
58:20 , of course, the confluence scout can shift places on. That's exactly
58:24 we see here, right? So is this is really pretty classic,
58:28 extreme, right? Then there's all little uh, you know, there's
58:34 all these little scour pits is, , sorry. You know, there's
58:40 scour pit there. There's a scour there. There's little scour pit
58:45 There's a scour pit, their little pit. There, those are all
58:49 certainly consequent scours. And then the kind of feels on top of
58:53 so scour and fill. All so, you know, you could
58:58 a progenitor scour fill. You interpret as a constant scour. By the
59:03 , what's absolutely clear is you do have bank attached point bars in in
59:08 example. Okay, now, the thing we did was just compared to
59:13 section of the castigate Blackhawk. Uh, now there's theory that shows
59:20 the that the bed form should scale the size of the river.
59:24 So dune height scales to about, , 6 to 10 times flow That
59:32 . Ah, bar again. I'm a lot of fluids. Seven
59:36 Ah, bar is a feature that the way. So if you're on
59:39 boat going down the river and you a sandbar, you have to go
59:43 you. That's what the board bar . So again. If the Black
59:47 was humid with less rivers, the should be bigger, and the dunes
59:51 prospects should be bigger. Yeah, pretty clear that the thickness of the
59:56 , uh, so here's a single story in the Black Hawk. At
60:01 finding up with units represent bar It's pretty clear that scale bar deposits
60:07 small scale cross beds are pretty exactly same between the Black Hawk in
60:11 casket. The biggest difference. And can maybe see this. The castle
60:16 is a pebbly sandstone with local strings gravel on the Black Hawk is fine
60:22 medium sand, mostly fine center never up to any coarse grains or
60:28 so the cast is actually coarse Where is the Black Hawk is a
60:34 find a great That's about all you say on the council gate is the
60:37 era night. The Black Hawk is living area, but the scale of
60:42 . In addition, you can you take the thickness of the,
60:47 or the height of the bars Those typically represent about 80% of the
60:52 depth, right? So, so basically, the bar height is
60:58 elevation drop from that circus to the right again. That's about three or
61:03 m. Right on. Uh, shows that that the Blackhawk rivers were
61:10 2.5 to 3, maybe 4 m . The casket rivers were basically exactly
61:15 same. So, uh, Susan Claire and her supervisor, John
61:25 did work on modern rivers and basically that that cross bed thickness, which
61:32 sm okay, eyes related to, to dune height h m on.
61:40 that, you can calculate water Okay, which is typically 8 to
61:44 times dune height. Okay, then , you know, a variety of
61:49 equations that once you know the water of the channel, you can calculate
61:53 belt with channel with the channel belt on DSO on and so forth.
61:59 these are just the calculations based on compilations Michael put together okay. And
62:05 pretty clear that the estimated mean doom is essentially the same between the castle
62:12 in the Black Hawk estimated channel that basically the same and so that there's
62:17 there's no measurable difference either by just at the rocks or even doing some
62:22 hydraulic calculations. There is no measurable between the castigating the black shit,
62:29 it kind of conclude this story. , the Blackhawk channels consist of overlapping
62:35 directionally down lapping lens oy, brave deposits. The bars exhibit both downstream
62:41 creation, and it's pretty clear the hole channels that Rock Canyon were
62:46 Okay. Emphasizing the black hole China's rock can immigrated. Now it is
62:52 that when we go, you 100 kilometers seaward we start to see
62:57 examples of Vladimir creating meandering channels in black hole. Okay, so I'm
63:02 saying that that there was never a channel in the Black Hawk, But
63:06 the low natural growth Blackhawk faces in a canyon in the more proximate area
63:13 Brady. That's possible price Canyon rivers lower discharge or maybe their distributor
63:21 and you may simply be looking at increase in meandering as the slopes get
63:25 , are on a flat, fully or, uh okay. The differences
63:34 the Cascade Blackhawk at Salon a canyon no major change in Rivers River type
63:41 style across the sequence boundary. The Hawk castigate were both braided on.
63:46 is evidence the castle may have been smaller, but they're also more mountain
63:51 it. So perhaps there's more erosion there. Also, Force agree.
63:54 I didn't mention it should is that about a 90 degree change and paint
63:59 between the Blackhawks castigate. That's critical that change in pain occurrence means there's
64:04 regional changing slope that requires tectonic We now believe that that tectonic episode
64:12 a major court, uh, courts you like unit in the film Thrust
64:19 on that resulted in in a new . Of course, of course,
64:23 in castigate time. So the differences composition from the black Black Hawk to
64:29 Castle Gate reflects the fact that the Gate Blackhawk boundary is almost certainly a
64:35 un conforming produced by this ferric deformation of folding thrust belt tectonics that change
64:43 the tilt of the basin and uplifted exposed new up land areas to deliver
64:50 court trips mythologies, nothing to do used to sea or sea level on
64:55 indication of a valley. So we that the preservation off over back mud
65:03 is not a function of planting channel . And, of course, we
65:08 not are not and will not be last people to say that. We
65:14 argue that river type cannot be broadly according to secret strata graphic setting,
65:21 and so we don't really think that that this bandwagon model is correct.
65:26 think the Arabic that was made was that the Black Hawk was meandering and
65:33 Castle games braided because of net to patterns, without careful analysis of the
65:38 internal geometry. Okay, we also out the plan for the geometry of
65:44 river deposits can really only be interpreted doing detailed faces. Architectural studies that
65:51 season correct, because there's a lot great three D seismic data that that
65:57 the plan to geometry of ancient river . Very well, so, so
66:02 . Good three D seismic data can you exactly what the plan the geometry
66:06 an ancient river looks like. Of , many workers and many textbooks and
66:11 managers of companies you may have the is miss misfortune. Working for may
66:17 be very, very, uh, to the braided versus meandering and
66:22 And, uh, you know, , the purpose of this lecture is
66:26 to ask you to be cautious and be aware of the technical work that's
66:31 to really make that distinction and to more carefully about about what is actually
66:37 to document a sequence strata graphic change flu. Viel successions. Okay.
66:44 so we would We would argue that placement of different environments of deposition and
66:49 faces into the same genetic unit is essence of sequence photography. So we
66:55 with Van Wagoner that this is a strata graphic interpretation. We believe that
67:00 is a secret strata graphic interpretation. the only thing is missing from this
67:05 Islamic Patterson's reinterpretations that the rocks that just showed you that shows a much
67:11 and more correct version of this. maybe we're going to take a break
67:15 . And I'm actually try to find paper. I got my laptop
67:20 and I'll show it to you when when we come back. Uh,
67:27 uh, I've got, uh, after 10 right now. Eso how
67:35 we take a maybe a 15 minute ? Unless there's a burning question you
67:42 right now. Or you can think your question. Either type it in
67:46 asking when we get back. Sound ? Okay, You got back 15
67:57 later. Okay? So before we questions, just I'll just show you
68:04 slides I put together, uh, the break, so I had to
68:11 . So this is a new paper Simon Paterson. And he's been working
68:16 book Cliffs probably nonstop since about 1990 92. Maybe, maybe even longer
68:26 that. And, uh So here's his recent reinterpretation, I say a
68:34 . He went in and probably measured times more measured sections than Fan
68:39 One of things you'll notice he's got forms in these in the distal
68:44 right? He's also used a bottom right. So he's changed the
68:49 Um, to a bottom hang versus top hang that emphasized the clown
68:54 You can also start to see the to direct a little bit more
68:57 So you know, we could do short introductory exercise. It's sort of
69:03 toupee. Then it's kind of p to a and then back to pee
69:10 he argues forcefully, that there's no of major sea level drops on
69:16 All the Blackhawk rivers. Uh, the button coming across so he hasn't
69:20 much of this is the castigate So he just sees it as a
69:25 into fingering mess. Hey, does deeper scours at the distal toes,
69:30 he believes a lot of that is scour, reflecting Esther and deepening on
69:36 . Maybe other people do interpret these . What's interesting is John. How
69:41 another colleague of mine who also worked area, gave a talk completely independent
69:46 Simon a couple years ago a PG came to the exact same conclusion.
69:50 they don't see any evidence of valleys the Black Hawk or the Castle,
69:54 is again very interesting conclusions. And Simon just put together his sort of
70:00 of of of, if you uh, the previous interpretation. He
70:05 it the conventional secrets photographic interpretation on his re interpretation that these Paris sequences
70:13 using a you see how he's shown difference between using a top versus bottom
70:18 . So here's got aggregation right this compaction in the flu via around,
70:23 because of compassion. Coles, which this unit look thinner. But it's
70:27 a compassionate effect because all the coals much more than the Shales. And
70:33 basically shows, you know, individual genic channels feeding their Delta's with no
70:38 evidence of major based double changes. then, finally, he sort of
70:43 together a block diagram that shows his of the Black Hawk castigates photography.
70:50 I will stick that up in the budget. It's just just a little
70:55 out to sort of show you how how the story has changed.
71:05 so before I continue, are there what what I'd like to do today
71:10 do again? It's still morning. a bit fresher, kind of get
71:14 . We got two more required lectures go, so I got another
71:18 That's, uh, just a lot examples of alluvial systems. Just
71:23 the sort of hopefully cement some of ideas of how to interpret correlate,
71:28 about filial systems. I thought I I would see if I can finish
71:32 this morning on Ben. We've got deep part of this afternoon I put
71:39 other lectures up, which is kind optional. So I might ask you
71:42 take a quick look at those over . I've got one on one.
71:47 my very, very latest paper on photography Popovich this year and another
71:52 which is sort of update on The time stretch short lecture. The
71:57 is longer. Shell may be of interest to you who are in
72:01 so we may have time for both them. Maybe not. We'll see
72:04 it goes this afternoon. I also to spend some time looking at the
72:09 you're doing on on Exercise five. last two exercises. However, you
72:15 we can do a workshop between them on those if if you need more
72:21 or or if you need help. we do have lots of options for
72:24 afternoon. So any questions about the Hawk talk that I gave?
72:38 Harry? None. I will make I've got all my participants out.
72:52 the chat. Okay, so I've my chat open. Just in case
72:56 wanna ask a question, I can all of you so you could wave
73:00 just turn your mic song and No problem if you do that,
73:04 , uh, we'll get started. , So the parents is a unit
73:13 I've been working on for no. years on it. It's a complex
73:21 delta unit. And I just thought give you some idea of our findings
73:25 how it relates to some of the in the course. So the framing
73:30 okay. Um, Miller and Uh um, sorry. Matthews and
73:40 suggested in the eighties that the particularly that the sort of Santa median
73:46 Santoni in May have been an ice time. This is Ken Miller,
73:51 Sea level history for the meeting, the Cretaceous to the Modern. And
73:59 , you know, since about about the past 15 20 million years,
74:05 has been completely covered with major ice . His suggestion with you know and
74:11 , and Antarctica in and of itself about 63 m of sea level
74:17 So if the Antarctic ice sheet sea level would rise by 63 m
74:21 green, nine melted, it would about 10 m on, of
74:24 the reason why I see that there so much lower at the last.
74:27 maximum is because of the contribution of Lauren tied ice sheet that covered North
74:31 . Aziz Well, Azaz parts of and Europe. Um, there's lots
74:38 evidence for high frequency, uh, sea level changes throughout the entire
74:45 On the big question is what controls . So there's a number of
74:48 one of the more recent is called , used to see, which suggests
74:52 that global changes in grab water storage enough to account for 10 to 20
74:56 of sea double change. And we've written some papers that debunk that hypothesis
75:02 criticize it very strongly. Miller's hypothesis they were ephemeral ice sheets on parts
75:08 Antarctica. The wax and wane, , weren't making a, however,
75:13 entire continent, but they were big to grow into K T. Be
75:17 to call sea level changes of the show. So his argument is that
75:21 caroni in which is to some of ice free time thes ephemeral ice
75:26 may have been able to account for 15 m of sea level change to
75:30 25 m, with increasing growth of ice sheets as you go into the
75:36 Cretaceous and then into the failure Okay, and the observations of these
75:43 frequency you see double changes, another development that you may or may not
75:48 heard Office called Astro Chronology. So the old days, you know,
75:51 had the Cretaceous period, we had , and that's the way that's how
75:56 calibrate the geological timescale. But the of it cycles occur at 2040 104
76:02 years. And if you can, you could time electric scale, toe
76:08 aged eight. Potentially, you could a secret strata. Graphic interpretation.
76:14 individual My lack of ex cycles people attempted to do that with great precision
76:19 accuracy for large sections of geological Obviously, Astra chronology worked very well
76:26 the last few million years because because have extremely high precision age states,
76:31 things like optically stimulated lesson optically stimulated and carbon, it gets harder as
76:36 go into deeper time because the precision eight states is worse. But I
76:41 tell you that we've been working with at Madison, Wisconsin, on they
76:48 theoretically able to get aged eight to of 80.2% on standings from 100 million
76:55 old rock. And if if you do the math in your head,
76:59 plus Iman is 20,000 years. So have the ability to calibrate sea level
77:03 in the center median to Santoni in develop an Astro chronology. I've never
77:09 work well because we're in the quotations normal. Okay, Mhm. Now
77:15 a passive continental margin. Okay, is greater at the sea would
77:20 And the hinge on is the area essentially no subsidence. Okay. And
77:26 know, in the in the creation the western interior basin of Canada,
77:30 gotta paint is a passive margin succession overnight by former base in succession and
77:37 base and substances greater towards the thrust it decays away towards the center of
77:42 basin. Remember? I talked about with Henry Postman tear and be zones
77:48 in our introduction to flu. Your cartography. Okay. And of
77:52 you know, for one of basins a lot more tectonics going on with
77:57 expressions of sea level changes. You from that the subsiding 40 to the
78:04 where you may get peripheral bullish Uh, but the flip side,
78:09 have a lot of good high resolution photography. The problem passive margins is
78:13 that there are always thinking. So you lift them up, you know
78:17 the record of security passive margins is more on on size with data.
78:21 , logs are supposed to detail outcrop . So our interest in outcrops is
78:26 we have much better resolution. The is you have more complicated subsidence history
78:31 uplift history. Okay, sorry Here's our step number one. Get
78:40 big picture. You know, shows the overall configuration of land, sea
78:44 basins and deltas at the time interval interest, which is the Timonium in
78:51 Upper Cretaceous and we're looking at the is broken up into three major Delta
78:57 , the notes and last chance and deltas. Here's a regional west to
79:03 cross section. Uh, that shows that the broad, regressive, transgressive
79:09 So this is a broad little So you have the Santee Dakota
79:12 uh, which is a regressive, regressive Senate repackage that deepens into the
79:18 the macro shell, which in this is renamed the tonic shale member,
79:24 by the fair member of the macro . That's over lane by the blue
79:28 . Out here, it's on Mac because you go to the center,
79:30 base, and that becomes a Okay, we could talk a bit
79:34 the geology of the Shales if we to the shale lecture, uh,
79:39 this afternoon and then that's overland by very broad package. And again,
79:44 with this lift, those photography we do a combination succession that that looks
79:49 bit thio p a whoops. All it P a and A grades.
79:56 it's that's a toupee, A Peter A. Peter A a two
80:03 . So you know, the broth broads exams can can actually be used
80:07 guess what the accommodation successions might Okay, on demand for this talk
80:15 be focused on the geology of the delta system. Um, most of
80:26 work don't ignore the red line there front of race it, but my
80:29 is being a bit sluggish. Most work on the on the most of
80:35 work on the Farron until I got . The game was done on the
80:40 this Delta sort of builds here. , Big Delta complex. And that's
80:45 the last chance Delta. But there's There's a gas field somewhere here on
80:53 . Uh, an AK crop belt extends from low all the way up
80:57 Price Utah. Okay, on the Farron sandstone stops around here.
81:02 then there's this so called noted Delta the south that represents a separate source
81:07 sync system that we've been studying for past 20 years or so.
81:15 Jim Garrison, who I mentioned before partner Coke Vandenberg, uh, Quick
81:23 and went to live in Emory, . And he put together a general
81:29 of the broad plastic wedges. There the last chance Delta, which looks
81:33 it's an overall third on the back . The NOTAM appears to be more
81:37 a degradation of forced aggressive system on John Henry member going into the drip
81:43 , which is which was key families de thesis with the low net net
81:48 gross, uh, John Henry feudal with the razor sharp contact on the
81:53 the drip tank member. I'm talking of that, uh, was Keith
81:57 PhD and that the Chi Parrots plateau to the South. Mukai parents is
82:03 in this area of Utah, so represents a major third order back
82:08 So So Garrison would argue that sort , like third or low stand transgressive
82:14 then Hiestand probably sequence set. So the sort of the broadest scale see
82:19 strata graphic framework we've already looked at Jim's work in some in some detail
82:28 we point out that we have ALS or aggregation of procreation. ALS
82:33 little little hints of D in places a little stepping back degradation again,
82:40 , degradation ALS procreation alone been aggregation a huge back step. And you
82:47 , of course, we could see this beautiful flu aerial photography. So
82:51 is his schematic cross section. Each these dots represents a measure section.
82:55 addition to these schematic panel, he extremely detailed panels of the geology on
83:01 useful to look at because they So the evolution of of flu,
83:05 systems throughout a classic wedge you can lots of evidence of single story channels
83:11 in floodplains. So low net to . Here's a single story channels much
83:16 . So these could be distributor trunk channels and then you've got thes
83:21 multistory channels. Okay, you've got channels that he interpreters incised valleys.
83:28 at the end, you have single channels again. So ah, wide
83:32 of different styles of scales of channels then the mud plugs basically are your
83:36 evidence for the actual geometry the channel the sand body that will be the
83:41 belt. To make sure you understand difference there is the actual there is
83:46 evidence of the active channel now filled mud once filled with water on the
83:51 that it made as it migrated laterally time. You could see some of
83:55 channels don't look like they migrated very . Others looked like they migrated quite
83:59 bit. Okay, um and then other thing is you could look at
84:07 individual channel. It's over lane by coal and underlined by that mud stone
84:13 track it to the delta that So this this little in size channel
84:19 feeds that delta. There's a little would shift to faces there. It's
84:23 much, but a bit of decision , So this is interpreted as a
84:27 a fairly short lived, very small valley. Mhm. Uh, there's
84:34 one place where we got a good view through the fair on. So
84:38 is Jim Garrison's detailed analysis of the channels. The Kokopelli Channel is kind
84:44 in the middle of the fair. at that. More details. Here's
84:47 that child about looks like. no, that's basically mhm,
84:58 outline of the actual active channel. . And then that's the belt that
85:03 channel made as it migrated in that . Now, what's clear is
85:08 you know, if you connect up points of the channel margin,
85:14 the channel, the channel is actually through time. Now, this adjacent
85:21 here is all floodplain. So this is basically lifting vertically and migrating
85:28 right? So if you want to of it, it's kind of it's
85:31 aggregation of channel with lateral migration. you repeat for that, because there's
85:36 evidence is programming. But this channel clearly lifting up through time. That
85:42 that the baseness subsided, right? this channel shows lateral migration and some
85:48 . There's a lot of cannibalization of the earlier channels with the next
85:53 So in terms of stories is there's little bit of one story, a
85:56 bit of another story, and then fully preserved third story. So
86:00 we have three preserved stories. but the only reason these lower stories
86:06 preserved is because there's been some aggregation the channel. It was purely lottery
86:12 . Then it would be a single channel that makes sense, so we
86:16 not interpret. This is a Okay, the channel is about 10
86:19 deep, so that's a that's a good sized channel. So probably a
86:24 channel now that there's this channel down called The Counting on Channel. And
86:35 this unit right here. And there's a lot of debate is whether that's
86:39 distributor, rechannel or in size Okay, there is what looks like
86:45 there is the lateral. There is vertical and lateral scale there, so
86:49 sand bodies was 5 10. You , it's it's about 25 almost 30
86:56 deep on its 5100 and 50 to 250 m wide. Okay, at
87:03 widest. So that's, you if that was a river channel,
87:09 , 30 m deep channel would be the size of the Mississippi, you
87:13 , And it's 215 years wide, quarter to Colombia wide that that would
87:17 a pretty big That would be a big distributor channel. And,
87:22 you know, when I started looking rocks, I'm like that. That
87:25 no sense to me that that's way big, right? And then it's
87:29 clear that this channel's got 1234567 eight staff stories. Okay, it's only
87:37 kilometers from the shoreline, and you get indications off channel forms that is
87:44 of more on the scale of, know, five or 6 m
87:48 So is this a five or six deep channel? That's that's that's incised
87:52 then a graded. Or is this big distributor channel the fact that it's
87:57 narrow? It was a valley. a pretty small valley. It's a
88:00 river, but it's a small okay? And of course, these
88:04 two stories. Inter finger with coal Kohli settlement So these are all eroding
88:09 marine Paris sequences, But the upper stories interfering with the floodplain.
88:17 Here is that the same system on is just another road cut about three
88:24 four kilometers seaward of this outcrop. . And, uh, this was
88:31 done by Mark Martin at the Bureau Economic Geology in 2004 and in 2000
88:38 , uh, round about 1995 96 I was at the Bureau of Economic
88:44 . Working with Mark Hey, was felt that this was a distributor
88:49 I said, Mark, you've got vertically stacked stories and each story consists
88:55 a meandering channel right indicated by the accretion lines. Said that you
89:00 it's got about 25. 20. 30 m deep incision. If that
89:07 a river, that would be an big river. You know, in
89:10 lateral creation bars show heights of about or 6 m that I think that's
89:16 five or 6 m meet sick five 6 m deep river again the width
89:21 things. Phyllis of 30 60 120 100 and 70 m wide. It's
89:28 hugely why, but you know that would be a fairly wide river,
89:34 know. And and this was interpreted the mobile research group as a distribute
89:39 Channel. So it was kind of . Andrew Mile was visiting UT Austin
89:45 a talk and popped up to the to visit myself and Bron Willis and
89:51 all looking at at Mark Martin's and you said, Wow, that's
89:54 pretty cool incised valley. And so was sitting there in my huh Uh
90:01 , anyway, So when Mark published paper in 2004 he have reinterpreted.
90:07 is in size value. You notice cuts up into cuts into three separate
90:11 sequences A, B and C, those were showing with flooding surfaces have
90:15 with the yellow and go back to talk on criteria for identifying and in
90:20 Valley okay, an erosion of surface three times deeper than the Paris sequences
90:27 adjacent to it. An incision that flew to the rocks in anomalous Walt
90:32 , violating juxtaposition to marine rocks. , down lap on lap of point
90:40 in the Valley. Okay, on off the units below So that every
90:47 sequence boundary truncation and on lap location on lap above. Anomalous juxtaposition of
90:55 Marie faces over marine faces and a additional, uh, surface. That
91:02 that's five times deeper than the typical story thickness. So every criteria for
91:08 valley it fits. The only problem it's a fairly small this feature.
91:12 it's about the scale of the Mississippi . And so for those scientists that
91:17 driven by but auto genic distributor channel , they prefer an interpretation of this
91:24 a distributor channel now somewhere. I'm I didn't put it This talk.
91:31 got a well, a diagram of , but, uh, I should
91:34 show you that in any way. I just stripped away all the geology
91:37 show you what you know, the between the channel and the erosion,
91:42 feats that informed. Okay. Now width of the valley is one of
91:48 biggest controls on value. It is duration off the time allowed for the
91:54 to cut the value. And if a sea level rise and fall short
91:59 , then the River just doesn't have much time to cut a very wide
92:03 . So my guess is that this quite a short lived fall of sea
92:07 , and it cuts a very small on because it's so small and so
92:11 to the shoreline. Ah, lot the research is even Jim Garrison,
92:15 know, really still insists that this a distributor channel, like he may
92:19 of agree that it might be in distribute Terry, but if it's a
92:22 by definition, it's it's not. value may not be an important
92:25 A big one. By definition, a valley. Okay, on the
92:29 of the channel, depth, which a maximum about my meters to the
92:34 , is clearly incompatible with this being distributor channel. Okay, so this
92:43 shows you this is an out of slide. This just shows you all
92:47 students that I've supervised who have worked me on the fair. Okay.
92:52 we got 123456 six PhDs and 27 in all Onda. Uh,
93:06 so, you know, if you to add up all the time it
93:09 for all of these PhDs, massive . And there's some undergraduates and there's
93:14 , David, by the way, graduated. Been graduated sometimes go.
93:18 this is a while mats long since . Natasha's graduated. Yeah. So
93:25 tiny right, you know, it's It's a lot of person power on
93:28 outcrop on. And, uh, know, the reason I put the
93:35 up here is just a just to you a feeling for what it really
93:38 to do Anak your it sequence trata interpretation it took It took Simon patents
93:45 30 years to really test the hypothesis John Bandwagons interpretation. John is no
93:51 . You know, John had armies Exxon folks. Now the difference between
93:56 on academic is, you know, the best of all company. They
93:59 will not send their staff out for months of time to do fieldwork.
94:03 piece students students will routinely do two of fieldwork for a PhD. They
94:08 have two summers, so that's four of fieldwork. But I promise
94:12 when you work for all company, lucky Lucky to be able to get
94:15 week or two a year in the . So although Exxon put together great
94:20 section, you know, it you know, it was based on
94:23 sort of short field bursts. I'll it over a long period of
94:28 Uh, Simon Paterson works university with graduate students. So he's just gone
94:32 every year. You know, for years, and just by sheer virtue
94:37 the number of years he's worked it has come up with a robust
94:41 of those wrongs. But the point , if you don't have at that
94:44 and if you don't have much you're gonna you're gonna have a less
94:48 sequence. Trata graphic interpreting Asian. , once again, these are some
94:55 the finest rocks in the world superbly . You can see the ton of
95:00 down here, the blue gate shale there. And then this is the
95:05 is the fare into, and you see these nice up, of
95:09 in units beautiful. A precaution. in the marine marine realm. And
95:14 those are over lamed by isolated channels bed with floodplains in the upper part
95:20 the fair. Okay, here's, there has been browning. There's gang
95:28 . So we do a lot of work on uh uh, these cliffs
95:34 ropes. Okay, now, here can see a nice set of delta
95:38 forms in and up, of Name Paris sequence with flooding surface on
95:43 and then another. Another parent sequence top of that. In addition,
95:46 have, ah, volcanic ash layers the base. So we have a
95:51 lower datum to do the work. , Uh, there is you Jew
95:57 didn't get his PhD on the dip . Photography. Hang on. Rope
96:01 there is Ryan Kruger and Michaela Mike last I heard works at Occidental
96:08 works for a small company called Sanchez , uh, in Houston, using
96:14 job make up staff and a hammer mark the point of shoot to measure
96:19 sections on. This is an example one of the diagrams from you J
96:26 again, a photograph of the of of this, uh, west limb
96:31 the of the of the banks of factory Butte. Same Klein.
96:36 There is the basis of Farron upper in Paris sequences. And then these
96:41 here represents the flu. You gonna of kind of coming and going
96:44 Then there is the tonic shale on of it. And then here this
96:47 shows the various Paris sequences, flooding and secrets boundaries that E.
96:55 Was able to identify in the field correlate across the area again.
97:01 props were experienced beautifully. I asked there is a better night's there.
97:07 can see these little little white markets Shales. So those the bentonite correlations
97:12 the first para sequence in the Farron the distance here. That's this.
97:15 Sandra felt the San Rafael swell and of them that's starting to poke out
97:20 . But there's a big flood back on the rocks. Continue off the
97:24 the left. Uh, these shells , uh, I had a student
97:29 a little bit of work on on shells here in extreme detail on That's
97:36 large part of the talk on shells I could talk about that student
97:40 then left University of Houston and went work with Juergen cheaper and Indiana,
97:46 is, you know, the god Shales and that his PhD on the
97:50 tenant shale that Avery Nice project on , There's Ah, smile off,
97:56 . One of my, uh, students are one of my master students
98:02 out one of these Ben, Tonight's exposed, uh, in the base
98:07 the town of Shale. And there's a close up that shows the weathering
98:11 the one of the thickest Bente mites we have. Of course,
98:14 in addition to using it for correlation also sampled it ended ages, dates
98:18 it to get the chronometer tree of fair. So you've seen this several
98:26 ? Eso I've shown this slide sporadically bond shows that the correlations and measured
98:36 again hung on the lower bentonite So this is an example. We
98:40 a good lower data. This is same photography with just with the measure
98:47 taken off. But of course, can, you know readily start to
98:51 the accommodation successions. This is largely of slightly presentational. Okay, there's
98:56 little bit of of retro gradation from to here on the system. Then
99:00 system goes aggregation to retro relational. it's aggregation to probe rotational. Then
99:05 goes strongly degradation all down this Then it starts to a grade,
99:10 it's just some shifting around a little . Then it back steps or retro
99:14 . Then it let's back up again it goes almost horizontal appropriation. Then
99:19 down steps or degrades down steps kind of recovers a bit, then
99:24 steps again. Then it degrades and to get a bit of lateral
99:28 Then there's a big kickback, a procreation, then another intense pro grade
99:35 , aggregation and then another incised And these last two degradation ALS stacks
99:44 we finally see the incised valleys expressed incision. And when we talked quite
99:49 bit about that yesterday, and of we can interpret those stacking cannons in
99:56 of the neoliberal combinations successions what's gonna coming back to the slides? Because
100:01 critical to understand sequence photography. and that's just an example of the
100:07 successions for the fair. An example just showed you. Of course we
100:12 . We could well arise that on . Uh huh. You could realize
100:20 . And somebody that's that's one of slide here, But maybe it Z
100:27 , eyes oldest live, but we've bentonite up here. We've got
100:31 Tonight's down here on. So we able to aged eight. These un
100:36 is to put a time scale the axis. I think that's another wheel
100:40 I showed you earlier on. and these sequences are clearly,
100:47 100,000 year duration sequences. So we good evidence from a lack of
100:52 Cyclist city in the fair. And addition, we could control we could
100:56 could use the shoreline trajectory toe measure magnitude of seat on the drops,
101:01 it looks like we have evidence evidence sort of maybe after 60 m of
101:06 over timescales of 100,000 years. So felt that that was unequivocal evidence from
101:11 lack of its scale. Cyclist We thought that provided circumstantial evidence for
101:16 hypothesis off ephemeral Antarctic ice sheets. was sort of the story there.
101:24 then, of course, we way notice that there was we sort of
101:29 to wheeler scenarios. The lower one some or uncertainty in the age of
101:35 units that fill the valleys, and sort of led us to the idea
101:39 dia. Cronus Valley fills that form the fall to rise cycle as opposed
101:44 the old Exxon view, where every during fall A None of it feels
101:49 late low stand transgressive times. And we also demonstrated that the the amalgamation
101:55 off alluvial systems within the fat valleys the transition to Coles and flooding surfaces
102:03 , really fit this Shanley McCabe model accurately. We also see similar evolution
102:09 Paley Saul's on other features that fit well with these general secret strata graphic
102:15 for flu for how feudal systems This is an example of the oblique
102:21 view so pale if it was sort in that direction. So this cross
102:26 is a little bit more dip oriented this cross section is almost perfectly strike
102:31 , and here you can see the channels showing up rather nicely. You
102:36 see bi directional down lap on some the Delta Delta lobes that indicate compensation
102:41 stacking okay, way not for students worked on the inside valley. Both
102:51 and David of David graduated last and Stephanie graduated about 2017 so they've
102:57 graduated for a while. The uh, on the base of 210
103:02 , Current missions, measurements, general in that direction. Okay. On
103:07 ripples show that what the, wave approaches in that orientation and coastline
103:13 probably speaking forint in that orientation. , you know, we have parent
103:17 data and regional, uh, data sort of tell us what the overall
103:22 geography is. So here's an example a fair and compound valley. You've
103:27 a couple of upper costing Paris Okay, The top one is truncated
103:32 this white sandstone here. That white is truncated by Matt Money on
103:38 uh, floodplain Phil. And then eroded by a younger, meandering
103:45 You see that? You can see Mandarin there. So we see at
103:49 three episodes of cutting Phil so good of a compound valley system. This
103:56 worked the cliff section done by another mind. Uh uh uh,
104:04 It was his name. Uh, was my favorite photograph. So here
104:10 have. Ah, upper cautioning shore here. It's truncated by this regional
104:16 surface. There's the sand stones of oldest valley three. Then Valley three
104:22 incised by valley to valley to is lane by a flood plain and a
104:28 point bar. Right? So there's nice, meandering channel that fills the
104:33 floodplain. Okay. And then that's over lane by another flu legal system
104:38 referred to as Valley one. So we see is a larger erosion.
104:42 scour filled by a river, and on lapping floodplain. So again we
104:48 a complete mismatch between the scale of channel on the larger scale.
104:53 Okay. Right. Um, when go to this area here, we
104:59 beautiful, deeply penetrating roots. So the inter flu. There's also evidence
105:05 dinosaur footprints all over the place and sorts about the great stuff s.
105:08 here's an example of what the Paley look like. This is actually a
105:11 play. This is a an Little tree. Okay, it
105:17 roots play out in this direction. can see the top of the plant
105:21 there. Uh, in these mud , blow this beautiful examples of down
105:26 bifurcating roots. Okay. And then see some cold layers that indicate that
105:31 air humid soils bearing environments of human results. We see 97 sense of
105:41 of, of, of, of variety of animals thes air. The
105:46 elements of a small, uh, small, probably herbivorous dinosaur.
105:52 this is the first dinosaur fossil ever in the fair. Sandstone by
105:57 And we were, um there is road. So we were We were
106:05 some work. Um, way we . Yeah, we were working
106:14 so I was leading a group of on this cliff section here. I've
106:18 taken about half dozen field trips Then one day, I just went
106:22 the street literally across the road uh, found that guy or I
106:29 a bone. I took the bone to the camp and showed it to
106:33 guys from the Berkeley Museum of Natural . And that worked on the Mars
106:37 sight. Said, Hey, what do you think about this?
106:39 I bought the whole group to that , and in fact, in
106:42 one of their pants just flipped over and found, uh, and found
106:46 rest of the bow. They took back Thio working museum prepped it,
106:50 we published a paper in science advances years ago. so I'm pleased
106:56 I found the first dinosaur ever found the fair. Um, e
107:00 I talked to Jim Kirkland, uh, is that is the chief
107:04 tolerance for the state of Utah. he said no one's ever found a
107:09 bone in the fair. And I it right by the road. Like
107:13 didn't even have to hike in I was just sitting there by the
107:16 . Yeah, it was a Yeah. I just want they tell
107:19 what, What part of it belong ? Yeah, that's that those the
107:24 vertebrae. So they would be from area. Uh, yeah.
107:31 so here is just a close up of the incised valley. Okay,
107:35 we see, uh, incision there . You can see it up,
107:39 course. In Paris sequence another upper in Paris eating in the sack of
107:43 is truncated by undulating, irrational Okay. And if we look at
107:49 at it closer, we could see beautiful evidence of of one, perhaps
107:56 maybe four stories. Maybe fifth one the upper one has unequivocal evidence off
108:01 in a lottery cream point bar. . You can see Ah, creation
108:05 in some of the lower stories as . Okay, this was extremely detailed
108:11 diagram that my PhD student Waleed id one of these lower channel stories,
108:16 he saw evidence of bi directional down locally. Okay. And so he
108:22 this as a braided river. where's the upper stories show? More
108:27 style. So, in fact, was an example. Where? But
108:30 lower fell in this valley, it like it was a greater channel that
108:34 reflect the high slopes formed during the incision. Paleo geographical reconstruction showed that
108:40 valley topography was about up to about to 30 m on the river was
108:46 probably about 4 to 7 m Okay, uh, the Valley Phil
108:52 extra formacion conglomerate, which is the little white, uh, court
108:57 Church particles, as well as large formation of mud ship rip up classes
109:02 those occurring the base of the Okay, Sometimes we see a nice
109:06 formation of conglomerates indicating steeper ingredient, grained river systems. Interestingly, these
109:18 , pebbles and cobbles are common in valley. Fills, but they never
109:23 to the shoreline, so they always toe to stop about five kilometers from
109:27 shoreline, which which may reflect a effect. And if you recall,
109:32 did some backwater calculations Farron and it sort of on the scale. About
109:39 to 20 about 5 to 20 Nice examples of uni directional doom scale
109:46 bedding typical of your directional flows. , you get little drapes. Sometimes
109:54 see rather impoverished by observation, with little vertical cylindrical burrows and some planning
110:00 , this almost certainly indicates brackish So some of the upper parts of
110:04 valley filled show a little bit of water effects that indicates that they're that
110:11 within the Bay Line to go back our Bay Line and Backwater conversation on
110:18 we see evidence for double mud You see these little parent mud drapes
110:23 on those double mud drapes are indicative title reworking of these doing scale cross
110:30 and again that suggest deposition within the backwater. So that allows us toe
110:36 the for the for the valleys that before we see the shorelines allows us
110:42 estimate how far away from the shoreline were. There's Ah, young young
110:47 standing next Thio Bo days, or you bought a family body.
110:54 nicknamed him Body because the body is . You could see the beautiful cut
110:59 of a meandering river increasing is going that direction. You can see that
111:05 bond on, actually overline, but little hard to see. But that's
111:09 That's the top of the channel. a great abandoned channel fill. And
111:14 there's a floodplain coal overlying there on can see a series of again
111:19 of course, the channels with some bedding. Uh, here you see
111:23 beautiful example of a muddy, meandering . You can see the Mandarin
111:28 and then it's cut into by a channel classic, a channel reoccupation that's
111:33 of migrating in an opposite direction. is an example of a laminated little
111:39 lake with a beautifully preserved tree Okay, and then that was the
111:46 top of the lake fill. This apparently solved, of course, that
111:50 of the plant was stuck up in air and was oxidized away. Where's
111:53 part of the plan that was permanently ? was preserved and petrified to become
111:59 wood. But, you know, know, these are beautiful textbook examples
112:04 off alluvial rocks. Okay? And close to the top of the Farron
112:10 that it's over lane by the blue shale above. Okay, uh,
112:16 addition, what was interesting is I looking at this area for years on
112:20 Earth. And then one day I looked it again and said, Holy
112:23 Comolli, You know, these are loops. Look at it.
112:30 right? There is a meander loop . There is the outer edge of
112:35 river. Okay, so these air then there's another chance that's cutting through
112:42 . Okay? And that flows in direction. This flows in that direction
112:47 flows in that direction. You could this little man groups here, so
112:52 I discovered these, you know, been walking over them for or you
112:57 , so I have been walking over because I didn't revisit this into this
112:59 much because I was interested in the exposures. But once we've done all
113:03 secrets photography, I put some students work on these plans. You
113:07 and he's a very rare to find the ancient record in detail, you
113:12 , see nice evidence of Of, , of Sandy, of sandy large
113:17 bars. And there's geologists there for on DSO. This is work done
113:23 Chen Wang Chen Liangyu. Hey, his embassy in 2013 went to Rice
113:29 , just finished his PhD with Jeff . Try our and he emailed the
113:33 day, and he's on his way Korea to start a postal,
113:36 South Korea. And so in when walk across the apple, which we
113:42 a beautiful ribbon Pharaoh structures. here they are, a little bit
113:46 view. Okay, these are made migrating tunes and they curve in the
113:52 of flow. Okay, so he able to walk across the surface and
113:56 the flow field of an ancient Cretaceous and you can see the flow.
114:02 Paley cards are curving, matching the curvature of the ancient river channel.
114:09 also mapped the grain size and so can see the outer cut Bank is
114:14 little coarser. We see that the would margin the bars, of
114:17 er and there's downstream finding which matches models for grain size variation with point
114:24 . Quite well. And then here his sort of final summation of the
114:29 of this channel from relatively straight. expands lottery at first, then and
114:35 the last stage. It shows some migration, and then I don't have
114:40 on here. But in the last of this challenge and it's plugged up
114:44 abandoned. Now, the additional thing able to do is to look at
114:49 the thickness of defining upward profiles. that gives us you know, particularly
114:55 you see the transition from from dunes ripples. The ripples represents the upper
115:02 of the channel filled on when you cross beds going to small cross beds
115:06 ripples in the floodplain. Once this gives us an idea of what
115:10 broadly saying broadly, a complete story like yeah, here. Here's the
115:16 channel phase. Okay, We can getting feeling for the channel depth from
115:20 cross sectional profile of the lower Okay, now, because we observe
115:26 doing scale cross stratification. Okay, can use the bed form faced off
115:31 Graham, which plots flow depth various grain sizes. What this diagram
115:39 is that you know, at velocities sort of between, say, 50
115:43 125 centimeters per second and channels it , you know, 6 m deep
115:50 a stable. If the flow velocity down to 25 centimeters per second,
115:56 a stable if it drops down to centimeters per second. No settlement transporter
116:01 at all. And if it jumps to about 102 m, 2 m
116:06 second or 70 per second, you up a flatbed or low altitude bed
116:12 . And of course, what we in the rocks is a dominance of
116:15 scale cross bedding. So that tells that the velocity during the formation of
116:20 dunes was between about 75 250 centimeters second. So roughly speaking, about
116:25 me either per second. Okay, we know the depth of the channel
116:30 we could get the cross sectional area our plan view, uh, reconstructions
116:35 cross sectional observations. We can now water discharge. So now we can
116:40 get some quantitative estimates as to the and scale this river Okay,
116:46 the Mississippi River flood discharges 40,000 cubic per second. And when it's not
116:53 , it's down about 5000 cubic meters second. Okay. Ah, when
117:01 do the calculations for the Farron, , it turns out to between about
117:07 to a maximum of about 1000 cubic per second. And those higher numbers
117:13 represent the flood discharge. So the calculations alone quantitatively demonstrate that that not
117:20 are observation Lee are the fairing channels or of Manitou less deep unless y
117:26 the Mississippi. But the quantitative para discharge calculations demonstrate the same. So
117:32 idea that was suggested by mobile back 2004 that the pharaoh represents the Mississippi
117:39 just nonsense. Okay, Perfectly good that happens to be wrong. But
117:44 required very detailed sentiment ology to prove that was an incorrect hypothesis.
117:50 the other thing that we could do look at the lateral on regional
117:55 changes to put to put together a dimensional paleo geography off the farm.
118:01 now we're going a little bit more in scale. And so what we
118:05 is evidence of incised valley that we on the cross sections on that feeds
118:09 nice low stand delta. What's interesting we see a very river dominated delta
118:14 the middle of the area on its . By too short phases on,
118:18 see variations in the period occurrence that that sometimes that the distributor, Eri
118:24 bars of building to the West. they're building the east. Sometimes they're
118:28 to the Northeast. So classic radiating car a directions so the other we
118:37 start to do is waken use, , quantitative analysis. So we have
118:42 lot of evidence that allows us to both the water and sediment discharge that
118:48 passed through this incised valley. So know how much water and sediment was
118:53 passed through the valley in the river was cutting. And, of
118:58 we've now mapped the sand in the . I'll sink. Okay, so
119:02 lot of the sand is deposited in Delta front, and some of that
119:06 might escape to some of these flanking phases, and that allows us to
119:11 a quantitative analysis. We call it fulcrum analysis, which the John Harbert
119:17 that says that, you know, you can find the Trump Stream,
119:20 could predict how much sentiment passed from point to the downstream. So you
119:25 predict the amount of sand might be downstream sink. What you need,
119:30 course, to know is how much passed, You know, uh,
119:35 much time was that river actually sitting , spewing its settlement? Of course
119:40 have. We've got 43 Paris We've got six sequences. I think
119:46 have 19 Paris sequence sets and we radio metric dates that allows us to
119:51 the durations off the cutting and filling these valley fields. Okay, It
119:59 like the durations of the valley fills on the order of maybe 14,000
120:06 So we think that's how long the was sitting there. Spirited sentiment.
120:11 in sequence to we've got information on width, the depth of rivers.
120:17 have information on the grain size You can estimate the slope to tend
120:22 on this floor. We can estimate loss of use in bed for phase
120:27 . We can estimate the water discharge we can estimate the bed load discharge
120:32 the settlement discharge. Okay, and discharged in cubic meters per second.
120:38 then we can integrate that over the of time you think the river was
120:42 there 14,000 years. The big question how much? How how much time
120:48 year was the river providing that much on? The short answer is,
120:53 know you have to go to modern data, and it looks like the
120:59 is pretty clear. Most rivers flood between a few days after about two
121:04 per year. So you know about days per year was 14 divided by
121:09 and 65. Uh, we have time doing that in my head,
121:13 , you know, it's a few of the time per year. So
121:16 in the human environment, the rivers flooding most of the time. That's
121:20 true on. So we made some about how much time the rivers
121:26 and ultimately we integrate the the amount time for Europe. The river is
121:32 what's called the recurrence frequency, or amount of the number of times the
121:36 experiences of flood integrate that over the years and Ultimately, we get a
121:42 amount of sediment that you know, range of of sediments, depending on
121:48 uncertainties of our parents. Hydraulic That gives us sort of low on
121:53 estimate of the amount of sand on amount of clay that that sentiment was
122:00 . And so it looks like we have something on this on the range
122:03 3 to 10 cubic kilometers off Sam was delivered to the to the
122:09 Okay, now, remember, we we've matched the area of the sand
122:15 ranged between zero in about 50 Right? So again, you can
122:19 can plan on that that or just a quick and dirty thickness and area
122:24 . We can accumulate that. There's on the order of about 2.5 cubic
122:28 of sand in that delta front. that's, you know, not that's
122:34 close to the three cubic kilometers That our low side calculation. It za
122:40 one third of the high side calculation . It suggests that our estimate is
122:46 to within a new order of It suggests that there may be escape
122:52 what is clear is that there is or elliptic, very fine sands out
122:57 this dealt shelf area. And of , there's sand in this short
123:01 So we think probably maybe about 50% the sand delivered by the river.
123:07 of it ended up out here on rest of it was carried by waves
123:11 the down drift area. So the , you know, so so what's
123:16 here? That's the number that your in predicting if you're trying to do
123:21 exploration search to predict how much sand theoretically possible to B. C.
123:27 of a river that you may have . This is a technique to make
123:30 estimate. It gives you an or P town gives you a low
123:35 or p 90. And then, you multiply that by porosity on,
123:39 multiply that by water saturation. You estimate a potential hard carbon volume that
123:45 be within that deposit on that that make you decide to either pursue that
123:50 if it's huge or walk away from , because it's just too small to
123:55 worried about. So, you and that's the business of prediction that
124:00 really are in ultimately. Okay, , the other thing that I was
124:06 during was constructing the size and scale drainage basins. Okay, on bond
124:13 . I just didn't prepare the geographic to do that. It looks like
124:17 that the drainage basins fed the fare the scale about 50,000 square kilometers.
124:23 are there's lots of quantitative measures if you know the size of the
124:26 basin, you could predict the amount sediments and the water depth in the
124:31 of the rivers on again. It's of allows you to make regional scale
124:36 to sink predictions about the proportion of that might be in a downstream
124:46 Here is a cross section of Web and size. Valley again shows good
124:50 of a compound and size valley with of fonder scale finding upward,
124:57 individuals, channel story deposits that build the overall valley. Here is an
125:03 of ah, valley margin. So is my stick shore face here.
125:07 this unit we call the monkey There's a monkey, okay? And
125:14 you can see the valley margin right . So we do see the valley
125:19 preserved in a number of places. have beautiful a Christian betting probably of
125:24 influenced meandering streams in this valley here with, uh, four stacked bars
125:31 a multistory channel deposit blue represents the Red represents the overall incision of the
125:38 . This is work done by one my master's students who didn't extremely detailed
125:43 . Architectural study off this valley field to the left. So that's the
125:49 field going to the left and again the oldest valley Phil. Here we
125:55 , uh, deepening, uh, and then deeply and cutting. So
125:59 valley is coming deeper and deeper and with time. Here is the un
126:04 exaggerated cross section with the measured sections faces blue represent mother faces orange would
126:10 the courses gravity faces, that I you a photograph off earlier. And
126:15 just shows the scale the channel that to produce this valley cut.
126:21 And then here is just some close of, uh, the complicated,
126:26 filled geology. Okay, we could ah wheeler diagram in that it shows
126:30 extremely sparse nature off the valley That's a wheeler diagram off that
126:37 right there showing its complexity. Uh, one of my PC students
126:43 detailed analysis of the valley It in area to the north, a
126:51 So the air I just showed you here. Um, go about 10
126:57 of north in the same valley system preserved to everywhere we look. We
127:01 evidence of three episodes of cutting What's interesting is the oldest couple.
127:06 looks tightly influenced. The next Valerie fills. That's flood based. The
127:12 Valley is flood capped on the youngest shows no title influence at all.
127:17 , uh, we wondered why that possibly be. Here is the wheel
127:20 diagram three Oldest value is tightly Flood based the Middle Valley is flood
127:27 , and the Third Valley shows no influence at all. And young Young
127:33 that this may reflect the evolution during step forced regression. So during the
127:41 first phase of Valley fall, short is the valley feel is within the
127:47 back water. So we get a dominated Valley film during the next phase
127:51 valley fall. The valley is out the title of backwater, but then
127:56 rises and fills again on you. title influence and then seal falls a
128:01 time, and the third Valley is so far away from the shoreline that
128:05 always fluid filled. So it looked a step forced aggression that really did
128:10 the kind of sea level behavior that's by glacial growth of glaciers again,
128:17 providing evidence of a Quaternary style forced driven by glaciation zones that would be
128:25 off ephemeral glaciation in Antarctica. So our regional sequence strata graph across action
128:33 Valley Phil and then the placement of units in the leader space just emphasizing
128:39 DIA critics nature off that value Okay. And so that sort of
128:46 that the valley was the Valley. was formed over a prolonged time
128:52 Okay, on that sort of flies the face of the instantaneous, all
128:57 model bypassed model of the Exxon Group that favors this new bottle that John
129:03 Burke and I put together. So old Exxon model. So to suggest
129:06 you largely have bypassed during the falling with trivial preservation of terraces and most
129:12 the fill occurs during the the Most stand and transgression. Our view
129:18 you may get deepening and narrowing during falling phase with significant preservation of falling
129:24 terrorists is that's what we think we in the fair. Okay, Way
129:30 quite a lot of work on these systems in the Sweetwater Gulch area just
129:38 emphasize the work that vote aided and of the other students here is just
129:42 move you. There is the top the Farron. Uh, sorry.
129:45 the Marine Paris sequences, the baseline valley, the low net to gross
129:51 on. Then there is the contact the blue gate shale above. So
129:55 a slot I showed you before. these beautiful that I don't need.
129:59 meander belts inter bedded with floodplain Saul's Paleo Shawls classic donation Thes air
130:07 History Souls, which has a organic coal rich environment. Ah,
130:13 of clay that's been slight leeched on a unit of clay that Z.
130:19 weathered. And then there's the crevasse , which represents the the If you
130:25 , the bed sort of sentiment producing Siris of petty assault horizons.
130:31 and there is the there is the purely salt horizons. And we did
130:36 estimates of the duration of these coals the time it takes to form these
130:39 souls to try to do some some strata. Graphic analysis of thes sits
130:44 arises. E think I may have coming up the at the end of
130:48 little section here? Uh, so did detailed measurements of the Paley
130:56 You may have heard of a bio Shin Index. He came up with
131:00 what he called the routing Index. the routing indicates indicates the aggressiveness of
131:04 Paley Saul. So it's very aggressively up until the base of the cold
131:10 . Okay? And he will be example of one of his police.
131:14 units. There's a crass play with muddy soil on top kept by the
131:19 . And then there's his routing Okay, forming a cycle of panty
131:25 development. These things are sometimes referred as Flavia lag relational cycles f a
131:31 . S on. He showed how stack up in the non marine
131:35 So we get floodplain cycles and of , we get funding upper channel belts
131:39 . The idea is to try to of look at the cyclist City of
131:42 in the floodplain do analysis that would similar toe what we do in marine
131:48 sequences. So that sort of generates idea. Effluvia aggregation of cycles developed
131:54 Stacy Actually and Stacy actually and and on by his his, uh,
132:00 student, Greg Cleveland, who is an Exxon. So these finding up
132:04 cycles and fairly salsa cycles represent these viel aggregation cycles that would be roughly
132:10 apparent sequence they group in the The vibrational cycle sets on those intern
132:16 flew viel sequences. Eso Here's an with Flavia Lag Rotational cycle. There's
132:21 base of the cycle. There's the caps, the cycle Okay, producing
132:27 finding up with facing succession. there's one below on. You
132:32 Mary Crowds in 1987 looking a floodplain saw similar things and the rocks that
132:38 worked on in Wyoming on Ben. Bodies cross section that says in Prep
132:45 he's long since graduated and published his Eso There's that There's the Geological Cross
132:50 based on measured sections. Here is example of his of his cycles indicated
132:54 routing. Thats represents the integration of and faces. So yellow represents the
133:03 . You'll fill oranges, upper You'll fill greatest floodplain. Red is
133:09 . Plays and purple represent little crevasse . And then the yellow represents the
133:15 Floreal channels. Okay on, that he in turn then interpret that
133:21 a zey Siri's off systems, tracks sequences. Okay, then ultimately attempted
133:29 wheel. Arise the floodplain. This one of the first attempts to do
133:32 wheel of diagram on floodplain successions. general, he described 21 flew feel
133:38 sets deposited 100,000 years. Uh, those sort of the 21 fluid iteration
133:45 those groups into nine, uh, aggravation. Uh uh. Cycle
133:51 And those in turn were grouped into high frequency sequences about 30,000 years duration
134:00 some lack of it. Cyclist city this floodplain. Okay, As I
134:04 , the non rain sequence photography were matches quite well with the Shani and
134:10 Moloch. Okay, uh, body , based on his careful paint analysis
134:16 suggested that that may have been some , uh, systems tracks that lacked
134:22 low status. So these would uh, what these would be the
134:26 Paris cycles of the seismic photography. periods of rise on still standard rise
134:33 still stand with no intervening, full cinema falls, which is why there's
134:38 secrets boundaries in the upper part of Farron. So when you just get
134:42 work, he just called that all . And then they went back and
134:45 that into some addition transgressive in Hiestand tracks, uh, at a series
134:53 massive students who also worked with body did Cem mapping of the alluvial channels
134:59 the same area. Their interest was to get a feeling for the width
135:03 depth of the channels. Uh, did some nice work with a projected
135:08 wits of the channel belts on either of Sweetwater Creek. And,
135:14 you know, that's a 50 m here. So that Z,
135:20 which is looking for the scale But these things range up to Maybe
135:26 in the second diagram here. So here's the width of the
135:30 about so ranging from the smallest 40 to about 250 m wide on,
135:39 , on. They converted the they trigonometry. So they use Paley currents
135:44 correct the apparent wits and the cliff to their true wits on that allowed
135:49 to plot them in the Giblin diagram try to determine whether these were valley
135:53 , distributor channels and rivers braided And they showed that the that the
135:59 channels plot sort of on the low of the gambling diagram, Certainly right
136:03 in the middle off his of his his, uh, of his
136:11 Um, and in contrast, we able thio plot the Valley dimensions and
136:17 , they plot well with they plot the sort of lower end of of
136:21 sandy, uh, a valley fills sandy alluvial strata. So the way
136:30 sort of test whether or not these fall within or outside of the range
136:34 theoretically possible dimensions for other channels or values, right? And what What
136:40 plot show is that our data fall smack with in the middle of these
136:44 giving giving us some some confidence that probably reasonable. Okay, so I've
136:51 some words there. I don't think going to read those because we're sort
136:54 one hour and 10 minutes, my get a little rough. You could
136:58 through those yourself and decide whether that's what I told you. Um
137:05 that that's kind of it for for political systems. Okay. Uh,
137:14 , So I'm gonna end there. , it's right now. I've got
137:18 minutes after 12. So are there quick questions before we break for
137:27 Everyone talking. You ready for a ? Okay, so you do have
137:31 homework to do over the over the . I do have to study guide
137:36 there, so have a look at . Uh, we have a couple
137:41 choices. We can either review that afternoon. You could sort of go
137:44 a little bit if you have any questions. I'm also happy to,
137:48 know, if JD wants Thio, a little 45 minutes or an hour
137:53 review between now and, uh, exam time on Wednesday afternoon, I'll
138:02 happy to do that again. There be some questions about the final
138:07 We will talk about the correlation exercises afternoon. I got the one lecture
138:12 deepwater that I'll give probably right after . Get that over with. Then
138:17 could spend the rest of the afternoon chatting. I can give you other
138:21 . Lecture of time strata graphic lecture . Depending on how we're feeling about
138:25 energy level is we could talk about . We could talk about assignments.
138:30 , weaken, review any questions on previous quizzes if you if you like
138:34 . So I'm hoping we'll have some and what we do this afternoon,
138:39 , way could go to the bitter . We could We could end of
138:42 earlier if everyone's feel they have what what they need. But there will
138:46 questions on the final about the deep . So we do need toe one
138:50 that we really do have to get before we finish up. So we'll
138:54 for lunch against It's pretty close to after 12. So let's meet again
139:01 how about quarter after one? Give an hour for lunch today. Is
139:04 okay? So, 1 15. . All right. We'll see.
139:08 guys in
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