| 00:00 | what are you Okay? Great. Well as you know I'm dr dre |
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| 00:08 | kind of know three people, I'm getting, get something of the whole |
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| 00:14 | time semester. And the main thing this slide is my email. Uh |
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| 00:22 | can go through blackboard to get to uh supposedly it's a direct link but |
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| 00:30 | always a little more comfortable of people go to w to pray. You |
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| 00:34 | studied you. Um The this course so accelerated that I don't actually have |
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| 00:42 | readings. I didn't say I don't you to do readings, but I |
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| 00:47 | you can't do all the meetings that want you to do. And so |
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| 00:51 | tried to kind of gives them some in terms of what I think are |
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| 00:57 | most important readings. Uh In addition notice that all of the the |
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| 01:06 | almost all the slides that I've taken the literature will have a reference uh |
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| 01:11 | England and a date and most of are in the reading list that's on |
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| 01:19 | website. So again you can go them as well down ripple, which |
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| 01:24 | your text. And let me just uh do all of you have the |
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| 01:29 | . Yeah. Yeah. Yeah. really need to get that. And |
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| 01:35 | if you look at the and and reason for that is that it is |
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| 01:42 | inexpensive includes carbonates and it's actually a good review. Um If you look |
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| 01:48 | the syllabus you'll notice I've given a to the Canadian Geological Society and you |
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| 01:57 | join that for $10 a student member then get the book for? |
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| 02:02 | It's as cheap as you'll ever get . So I do recommend you get |
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| 02:07 | . Okay. Uh and so I the reference FM four, which is |
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| 02:12 | models for or the chapter within it the court. Um, Sounds |
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| 02:25 | Okay, so let me again, talking about sediments and then towards the |
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| 02:29 | of the the uh lecture, I'll a little bit more about the |
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| 02:35 | Okay, As I go over the , of course, when we're talking |
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| 02:40 | sentiments, there's there's a variety of of thinking about them. Uh and |
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| 02:46 | of the important distinctions is, are sediments that have derived from within the |
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| 02:51 | basin, which they are. Talk us and those that are derived from |
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| 02:56 | the deposition. This particular course focuses on optimus settings. Uh sediments derived |
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| 03:05 | within the definitional basis are extremely And carbonates not so much in this |
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| 03:11 | here. Okay. All when we of a locked in the sediments, |
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| 03:17 | mainly there. To original, they to as to Origen Isse that is |
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| 03:22 | derived from um outside the deposition of And that's about 65 have all sedimentary |
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| 03:31 | . Okay. And ironic play mud being the most dominant uh said mainly |
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| 03:38 | because pyroclastic rocks are also included. not really the subject of this |
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| 03:43 | Yeah. Uh so there is a confusion sometimes here. Uh original |
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| 03:52 | Selous classic. but what's the difference who cares? Well, I've told |
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| 03:57 | about. The original classic basically means from pre existing material broken up, |
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| 04:08 | it could include a lot on top this material that is material from within |
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| 04:14 | basis. Uh So rip up uh some limestone material, uh shelf |
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| 04:22 | , etcetera. Uh those would be , but they wouldn't be original. |
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| 04:29 | . Uh the other solicit classes, is maybe the most common. We |
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| 04:33 | alternative to richness. And that's basically minerals. It excludes plastic mineral farm |
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| 04:43 | non silicates. Um and so there's to using each um each excludes a |
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| 04:52 | that I'll be talking about. Um rigidness is the easiest for me to |
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| 05:00 | because when I look it carbonates, I'm really mainly interested in carbonate fragments |
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| 05:08 | from outside the definitional basis. And re deposit. So that's going to |
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| 05:12 | most of the carbon. Is look at having said that when we |
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| 05:16 | into shells, that's not the So, uh as usual, shells |
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| 05:21 | expensive case here, we have folks subdivided rocks into true itchiness. And |
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| 05:29 | chemical rocks. Okay. Uh the is I'm going to be dealing with |
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| 05:35 | upper hand and of course, dr was the Lord of this. You'll |
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| 05:41 | see there's a lot of overlap, in the first few lectures and his |
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| 05:45 | in mind. Uh I think it's . I wish I knew a little |
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| 05:50 | of what he does. Sometimes he me. Sometimes I call Yeah. |
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| 05:56 | having said that if you have any , mm this is meant to be |
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| 06:05 | casual as you like. So please hesitate to ask me a question if |
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| 06:11 | was covered in his class that didn't fit and what I'm saying, if |
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| 06:15 | if you're confused, uh ask me or sp at the end of the |
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| 06:22 | . Okay. Now if we're going be taking a kind of a big |
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| 06:28 | view for a little while, certainly . Uh and we're looking at the |
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| 06:33 | sediment distribution system from the production of source area to the deposition of sediment |
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| 06:40 | some kind of a sink. And uh the way increasingly we're dealing |
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| 06:47 | that or referring to that is sourced sink and uh this kind of a |
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| 06:54 | approach to sedimentary rocks recognizes that there a lot of influences on that ultimate |
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| 07:05 | will sink, which is the sediment rocks that remain mainly interested in uh |
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| 07:13 | have been inherited from that transfer transit the source area into the sink. |
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| 07:21 | like loss of unstable come homes finding it's that Okay, so I'm |
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| 07:30 | going to be kind of subdividing this into looking at things that are influenced |
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| 07:37 | our in the source area uh in the tectonic and climatic setting in the |
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| 07:44 | area and how it affects texture, composition, how transportation history modifies both |
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| 07:51 | and composition. How that uh the environment in the sink of choice is |
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| 07:59 | to be the focus of the course realizing they've inherited that material and ultimately |
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| 08:07 | we'll talk a little bit about what to those sediments and sedimentary rocks as |
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| 08:12 | are subsequently buried in altered genetically. , uh just very briefly uh tectonic |
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| 08:21 | tends to control the parent material and relative leaf that also influences the |
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| 08:29 | Some types of weather. A climate influences weathering uh both in terms of |
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| 08:37 | solid and dissolved components. Transportation modifies sediment by abrasion selected transport in c |
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| 08:47 | weathering etcetera. The environment of deposition rearranges those particles into a three dimensional |
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| 08:58 | of little fishies and of course burial die genesis by increased temperature and |
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| 09:05 | Uh things like compaction, imitation, , fluid expulsion migration. All of |
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| 09:11 | things are going to ultimately influence the rocks that is petroleum geologists were interested |
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| 09:18 | . Okay, uh so again, going to focus on definitional systems but |
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| 09:23 | going to lead us into that by at some of those controls on those |
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| 09:29 | of systems. Now again, a definitions uh that we all use intuitively |
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| 09:38 | sometimes there is some confusion uh got pretty good sense of what a deposition |
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| 09:44 | is. It's a geographic area characterized some set of deposition processes. A |
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| 09:52 | is a linkage of deposition environments, contiguous or adjacent. Uh So we |
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| 09:58 | be looking at a marine system or system or even within a link clustering |
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| 10:06 | . We have a lot of different environments. Sub components if you |
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| 10:13 | Each of which leaves its signature in sedimentary record. Uh The other thing |
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| 10:19 | word we use and there's a little ambiguity with this and that is uh |
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| 10:24 | . Uh When originally defined it was sum of all mythological, independent illogical |
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| 10:32 | . Uh huh A working definition. think about the more important thing characterized |
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| 10:41 | little logical structural when they say They're talking about sedimentary structure and organic |
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| 10:50 | . The second thing is that it field basis. These we use the |
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| 10:55 | face. She's based on criteria that discernible in the field and their objective |
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| 11:03 | that's a real important point to make we've allowed fishies to drift into a |
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| 11:10 | interpretation. So you'll see reference to flu ville faces or a channel bar |
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| 11:19 | sheet, strictly speaking. Uh That an interpretation. And one of the |
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| 11:27 | that I want to emphasize throughout this is the distinction between observation and |
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| 11:36 | And so we try to keep those uh easiest affirmation body rock with specific |
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| 11:45 | , albeit the characteristics typically our mythology in infrastructure and fossil content based on |
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| 11:55 | characteristics. Okay, now we sometimes about a sedimentary fishies and so we |
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| 12:02 | to restrict it within a deposition system this is where we get into that |
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| 12:09 | . Okay. Um and so one the textural composition of structural characteristics resulting |
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| 12:17 | the accumulation of modification in a specific . I get a little frustrated by |
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| 12:25 | use of the term faces because we've from objective to interpret it. So |
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| 12:31 | I'm going to suggest we do is think about little fishies and other types |
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| 12:40 | a little face. She's is basically on mythology. And when I say |
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| 12:45 | , I'm including sedimentary structures. Uh so we're gonna look at literature |
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| 12:51 | I'm talking about things that describe the faces and then the interpretation of those |
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| 12:57 | faces, the origin. So little might be inter bedded sandstone, no |
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| 13:05 | . Uh the interpretation might be titled . So wherever we can't keep separate |
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| 13:14 | observation, als, fishies and the interpretation uh, of the deposition |
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| 13:21 | Okay, now we've we've extended the faces into a lot of different settings |
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| 13:27 | based on fossil content, based on fossil content, based on science signature |
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| 13:34 | characteristics, even fault characteristics. So she's has gone well beyond the original |
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| 13:42 | interpretation to include a lot of different . And the only thing I would |
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| 13:48 | on here is that this is a term, but it should always be |
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| 13:54 | . I'm sorry. You should always objective and not just here. |
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| 13:59 | Yeah. We talked about face. track, we're looking at uh contemporaneous |
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| 14:07 | face. She's like here in a visual system? So we're looking at |
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| 14:13 | levees, the point bars. The filled, uh, crevasses and |
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| 14:18 | Like so all of these would be of the deposition system of alluvial system |
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| 14:24 | subset. And we're gonna look at characteristics of each of these as we |
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| 14:29 | wrong. Now, one of the we commonly do uh, is to |
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| 14:35 | well thers law because although we Live a pretty much two dimensional landscape as |
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| 14:45 | , we spend a lot of time a two dimensional vertical escape, Be |
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| 14:51 | a course, cape clips kate. so we we would like to be |
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| 14:55 | to relate those laterally contiguous species with vertically observed little faces. Okay. |
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| 15:05 | we can do that through loss of , assuming it's a conform herbal |
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| 15:10 | This is a key point that is any significant erosion surfaces. So if |
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| 15:16 | is our lateral sequence of a mountain rivers going into a coastal zone, |
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| 15:23 | , then that's a vertical sequence. as long as there's no in eruption |
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| 15:30 | erosion, we can assume each of vertical little fishies was laterally adjacent at |
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| 15:38 | time of deposition. Okay, so me just stop and ask you for |
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| 15:42 | second. Is this a transgressive or sequence? Yeah, prestige. You |
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| 15:56 | to speak, wow. Regress. . Why do you say that? |
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| 16:05 | . It was like sea level with ? Yeah, it will work |
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| 16:13 | Okay. What do we see? . Are we going from uh deeper |
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| 16:25 | violence or deeper or shallower? Yeah. We're starting, yeah. |
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| 16:43 | top is the marine deepest. The quality is Lord facial sands which are |
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| 16:57 | it's a long transgressing. Okay. and so we'll be talking about transgressive |
|
| 17:05 | sequences a lot. Uh The thing would just note here the trend. |
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| 17:12 | is a bad example only because transgressive are rare and the reason for that |
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| 17:19 | either rare in coastal settings, which where we tend to use it because |
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| 17:24 | erosion during transgression. So what is common in coastal settings or regressive |
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| 17:32 | Okay, now, if you look walter's law in a little different Holbrook |
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| 17:37 | maybe I'll have a nice example. basically, what they do is they |
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| 17:43 | at the environment, they define it terms of the process and then look |
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| 17:49 | the find out of those processed and that really summarizes the one of the |
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| 17:59 | themes of this course to subdivide an into components with specific geological and biological |
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| 18:11 | which have a sedimentary signature. And course what that does. It allows |
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| 18:17 | to then described. We construct an . So here we have a programming |
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| 18:34 | regressive scene, we would go offshore to into non marine and then there's |
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| 18:42 | emotional surface. And you start off erosion surface caps on. Yeah. |
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| 18:52 | applicability the bosses. And so what see in here are the kinds of |
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| 19:01 | that are interpreted from the sediment research these kinds of events are then recreating |
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| 19:13 | a laterally constituent. You assess Okay, so here we've got a |
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| 19:20 | faces track of a wave dominated Looking at some of the sediment |
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| 19:27 | Uh we break it up in the shore face etcetera. We'll spend lots |
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| 19:34 | time on this later. But the is that if we know the lateral |
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| 19:42 | and the types of sedimentary structures, we can interpret that into a well |
|
| 19:52 | face to face the sea and in crop, they might look something like |
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| 20:00 | . And this particular seat basically begins a transgression flooding surface and erosion immediately |
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| 20:12 | statements is truncated by the transgression. That is basically what we refer |
|
| 20:19 | Common is a pair of sequence. many of you have heard that term |
|
| 20:26 | ? It's pretty commonly used, but want to make sure that we |
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| 20:30 | Um And basically those flooding surfaces, are the bounding surfaces of the parents |
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| 20:39 | are also the bounding mm surfaces of uh where walter's lost trickle. |
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| 20:49 | an example of this might be sitting , we've got Aeolian uh eroded and |
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| 20:56 | by uh offshore marine. Clearly this doesn't exist in any laterally continuous |
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| 21:06 | Clearly this is a transgressive marine flooding . Now we're often kind of forcing |
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| 21:19 | to look for a deposition of models we're making deposition models and they're really |
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| 21:26 | useful. You you look at a of different things. Local examples include |
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| 21:32 | and ancient summary fans. Okay. then you distill the characteristics of |
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| 21:38 | Try to summarise it into specific features in order to do things like compare |
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| 21:49 | observations, interpret predictor and these are of the rationale or why we use |
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| 22:02 | that's a shame on their useful. problem is that we're trying to a |
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| 22:13 | and the local example differs. So do you do? Do you change |
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| 22:17 | model? Do you change the I suggest you go do that. |
|
| 22:22 | But the reality is that we tend develop more and more models until uh |
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| 22:29 | some point they're no longer models. just another example. Uh flu vo |
|
| 22:37 | were like that submarine fan models are that. We could go through a |
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| 22:43 | list of where people keep proposing in deposition mark. Okay. And it's |
|
| 22:52 | to the point where the really the of a model in which you're trying |
|
| 22:56 | constrain your observations to a pre existing has really lost this flavor and his |
|
| 23:07 | what we're doing now instead is trying reconstruct the deposition environment. Bye defining |
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| 23:19 | series of architectural elements based on the were looking and and what that |
|
| 23:28 | it's a subdivision, particular system that's by a specific distinctive geometry and assembly |
|
| 23:40 | . Mhm. Uh huh. These , these faces are directly related to |
|
| 23:47 | . We can see in the modern channels or bars. And there's a |
|
| 23:55 | from very small things that build into and bigger and bigger things. So |
|
| 24:01 | could be talking about a ripple bar a channel or a removal system and |
|
| 24:14 | these are are the building blocks of the environment of deposition for what you're |
|
| 24:24 | in, not what somebody else's solve other place that although maybe similar isn't |
|
| 24:32 | . Okay, now what we do we subdivide our rock systems by the |
|
| 24:43 | of betting geometry and bounding surfaces. bounding surfaces are really time locks. |
|
| 24:52 | what they do they allow us to from the rock record a an entity |
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| 25:02 | or a package of sediments deposited during specific time interval. Okay. Uh |
|
| 25:09 | what you're doing is you're reconstructing the geo morphology. Um The rocks in |
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| 25:17 | . Now the bounding surfaces though are important and they are I would argue |
|
| 25:25 | and find the mental to applying the of architectural elements and in my mind |
|
| 25:32 | and reconstructing processes by which your sediment . Uh How many here have heard |
|
| 25:40 | a wheel or gotten? Yes. . Okay. Uh We are diagrams |
|
| 25:47 | very useful. I don't I don't them a lot conceptually because here is |
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| 25:53 | rock, I mean a cross section the track and the little line you're |
|
| 25:59 | lines, Those are all erosion And what if we do not drink |
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| 26:05 | is to stretch that out in So that the road, health services |
|
| 26:12 | are course, just a little line Iraq. The system can represent what's |
|
| 26:21 | . In fact, very clear. that any given place? Most of |
|
| 26:25 | geologic record is missing. We deal just an intermittent, irregular sampling of |
|
| 26:33 | that happened to be preserved here. . And so each of these is |
|
| 26:39 | type of bounding service. Now with much time, it is a pretty |
|
| 26:44 | banks surface. But if we start internally, we're going to see |
|
| 26:48 | smaller surface. In fact, we vision oh, a big Package of |
|
| 26:57 | Wisconsin in Northern hundreds of thousands, of views. And those are surrounded |
|
| 27:03 | so we can extract from that. unit that was taught to enjoy |
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| 27:12 | Million. Sure. 100,000 users. , subtract Oh, extract uh, |
|
| 27:28 | unit planning and what we're doing is are looking at yeah, events that |
|
| 27:42 | more and more closely related. down here in bed for migration is |
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| 27:53 | by a surface. Doesn't necessarily have be an erosion of service, but |
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| 27:58 | a bounding surface. They're literally represents time took that ripple tomorrow. |
|
| 28:06 | the other way we can talk about that are basin. Why? |
|
| 28:11 | that's okay. Okay. How's your ? Okay, good, good. |
|
| 28:22 | . And so I actually, this from this article here. Um, |
|
| 28:27 | of you have already had doctor about , course of, some of you |
|
| 28:31 | have a couple of people will have and this is really a very good |
|
| 28:37 | . Doctors topics. So what we is that we started with U- |
|
| 28:46 | say cheese. You might combine You get a station in the |
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| 28:56 | We're going to take the settlement defined services to create a higher heat of |
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| 29:04 | . Yeah, there are from We're going to reconstruct the depositions |
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| 29:12 | Mm. If you're so fine, can create your own deposition online. |
|
| 29:17 | in reality, what you want is model that describes your rocks that can |
|
| 29:23 | used for prediction. Okay, so might be a barrier island title in |
|
| 29:31 | deposition law. Okay. Uh, is how you might reconstruct. So |
|
| 29:40 | might look at bounding surfaces. It's jim Geum or fic components of that |
|
| 29:51 | system, a shore face and the fill the barrier core flood pedal will |
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| 29:59 | the fan. Each of those subdivisions a distinct character assemblage of processes, |
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| 30:09 | erosion and deposition, which leave a assemblage of sedimentary structures and biological |
|
| 30:20 | So that's our goal to be able subdivide what we see in the packages |
|
| 30:26 | reconstruct the setting in which in form we can do that. Pretty much |
|
| 30:34 | system you want uh with the global . We can start raised bed bed |
|
| 30:41 | based in bars and channels channel like as complex issue. Now. In |
|
| 30:49 | start with this, this is what see and this. But as you |
|
| 30:55 | it, I often approach it from point to build up. So how |
|
| 31:02 | approach interpreting creation destruction field or the . Um You come from both |
|
| 31:10 | You kind of take a big picture frick it and you take a little |
|
| 31:16 | and expand. Okay. Uh d of sediments the same thing. |
|
| 31:22 | Okay. So what are some of controls that were conservative? Yeah. |
|
| 31:28 | we've got our auto and a low again. Auto genic factors associated with |
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| 31:35 | deposition violence might be low shifting channel , lateral migration in central. |
|
| 31:43 | Allergenic factors are external to the involvement position. Things like accommodation space, |
|
| 31:51 | tunnels, climate sediment supply. Uh I'm gonna be focusing a little |
|
| 31:57 | today and for part of tomorrow on allergenic factors. But as we begin |
|
| 32:04 | look at specific deposition environments, we're be looking mainly at the auto hygienic |
|
| 32:10 | . So let's look at accommodation space . How much I've got a |
|
| 32:16 | I've got to deposit those settlements. systems. This water depth is pretty |
|
| 32:22 | forward. Uh For for alluvial system a little more complicated because base level |
|
| 32:30 | or may not be tied to sea equilibrium profiles of a river system. |
|
| 32:36 | extreme can vary and that can create space if you like create room for |
|
| 32:45 | or the degradation. Uh in both , subsidence is a factor tectonic lee |
|
| 32:53 | subsiding from a controlling point of uh fluid withdrawal subsidence from engineering point |
|
| 33:03 | view. Um So when we look water death, because now we're getting |
|
| 33:10 | look at water death. Now we're to look at those variables that influence |
|
| 33:15 | ultimate level and how much room we for those sentenced kim. Yes. |
|
| 33:22 | it possible for sediments to accumulate without space? Um Aeolian will. But |
|
| 33:32 | problem is accommodation versus preservation. Uh and aeolian dune can build up, |
|
| 33:42 | could argue the accommodation space for windblown . Is the atmosphere? Okay. |
|
| 33:49 | but how much of that is not away? Typically has to do with |
|
| 33:58 | like changes in basement. So, there is some deposition will relief in |
|
| 34:07 | environments. Okay. Uh but that is defined by the environment. And |
|
| 34:15 | we want to see the accumulation of settlement through time, we need some |
|
| 34:21 | of preserving it. And so that's base level changes. Police. We'll |
|
| 34:28 | , okay, basketball. Yeah, . Base level. Those points stream |
|
| 34:34 | though we can change the base level they could be late. Well, |
|
| 34:40 | be internal drainage mm important here is there is an equilibrium profile for |
|
| 34:50 | And so that profile can change even it's graded to the same base |
|
| 34:57 | So we can have vertical oppression. alluvial deposits or down your decision of |
|
| 35:05 | deposits due to changes in the equilibrium that's usually the result of climate |
|
| 35:12 | Okay, So there is a point three uh river hits facebook were based |
|
| 35:21 | it really is no longer an issue rather its amendments. And we begin |
|
| 35:25 | add up screen improved. So we actually subdivide flew to assistant to a |
|
| 35:33 | base level control system in an upstream control system. Again, we'll talk |
|
| 35:41 | about that when we talk about river . Okay, well it's, it's |
|
| 35:48 | to visualize the role of base level regressive coastal systems. This is a |
|
| 35:54 | , either a barrier or a strand system. Okay. Uh This is |
|
| 35:59 | transgressive barrier system. Same day So there are some big differences even |
|
| 36:08 | the same setting, in the same level between transgressive regressive barrier islands. |
|
| 36:21 | the sea is transgressive. Yes. got basically transgression. We've got very |
|
| 36:30 | barriers deposition face the threat then here we have regressed? So we want |
|
| 36:39 | know what's the difference? What's controlling two very different kinds of said? |
|
| 36:46 | I'm sorry, deposition environments. And answer is the sediment budget two is |
|
| 36:52 | trying to quantify sources and sinks, segment over specific universe and the easiest |
|
| 37:01 | of thinking about it is that it's net loss or gain upset. |
|
| 37:09 | In costal regions which was the example looking at. It's mainly the rate |
|
| 37:15 | which sediment is removed by the marine ways and time versus is being replenished |
|
| 37:25 | sofa. So we have a supply sediment, we have a rate of |
|
| 37:30 | . Is it balanced? Is it negative sediment budget or positive sentiment |
|
| 37:36 | And that idea of positive negative sentiment is crucial to interpreting how deposition systems |
|
| 37:47 | rivers or because because what it says that if you add said this is |
|
| 37:55 | God, you're gonna kill his towards easy enough if you and energy go |
|
| 38:09 | erosion. And so the balance if you need to start adding more |
|
| 38:13 | , are removing more sense. And example how this works is building a |
|
| 38:19 | . And I'll show another example. show this example later, but uh |
|
| 38:24 | building a dam, we remove the from the down train route. |
|
| 38:30 | We haven't necessarily removed the energy. what happens when you remember? |
|
| 38:36 | you begin in the road, so downstream river begins to down cut. |
|
| 38:41 | of course in doing so it's reestablishing settlement vote. And so the river |
|
| 38:48 | getting back to an equilibrium by which has enough sediment. The discomfort. |
|
| 38:56 | not sure how comfortable it needs to , but it's imbalance with respect to |
|
| 39:00 | energy and and rate of participation, spend. You've created, you created |
|
| 39:06 | accommodation says uh well, that that's deposition. I'm talking about downstream of |
|
| 39:13 | dam, downstream of the dam because removed sediment from that river unless you |
|
| 39:21 | the discharge or energy of that That river is now sediment star. |
|
| 39:27 | a term in the literature called hungry and that river will begin to |
|
| 39:34 | Okay, similarly, of course, , what you've done is you have |
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| 39:40 | you've changed base level and you uh the sediment supply to increase in terms |
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| 39:50 | appropriations. So let's go back to various system. Here is a regressive |
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| 39:56 | which basically says we have a settlement , there's more sediment being supplied to |
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| 40:02 | coast than energy. And let's just wave because it's easiest. Then there |
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| 40:08 | wave energy to remove it, removing congress in that transgressive system and the |
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| 40:14 | deficit, there's not enough sediment. we basically are eroding and certainly conceptually |
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| 40:23 | it has happened. You can imagine balance, notice how we have heard |
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| 40:29 | position that is why something is going to give us accommodation steps. |
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| 40:35 | same thing here. Uh, there's some rise. And so we've got |
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| 40:42 | creating accommodation space at the time. same time. We are. |
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| 40:49 | Changing sentiments of our same thing down . There was a rise in sea |
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| 40:55 | increase in accommodation space. So we kind of graphically think about that at |
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| 41:05 | level sea level accommodation space versus budget positive. And this is one |
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| 41:19 | the things to keep in mind the concepts of sequence photography based on sea |
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| 41:24 | changes. Assume that when sea level there's transgression. When sea level |
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| 41:32 | there is regression maybe regression during high . Yeah. But the reality is |
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| 41:40 | and regressions are not just the result yeah, sea level or accommodations. |
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| 41:50 | They are also result sediment supply. we're gonna we're gonna look at the |
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| 41:56 | and control sediment supply and see how positional systems change is sediment supply |
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| 42:04 | Okay, so this is what's called normal regression constant. Sea level shoreline |
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| 42:13 | Murphy. Now another type of normal . Oh that's is that correct? |
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| 42:24 | type of transgression Because also if you but notice now we all forgot |
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| 42:35 | Well, originally when we were thinking secrets particularly rising, sea level was |
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| 42:40 | to be resulting in transgression. But this case and this is not a |
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| 42:46 | . The rate of seven. So is enough to at least episodically had |
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| 42:52 | radiation even though sea level. So these are normal. Um Now |
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| 43:01 | got to drop right or and we corporate asian. And this is called |
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| 43:08 | force regression. Okay, basically the is forced being forced to go see |
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| 43:19 | as water levels dropped. Now as turns out this is strong, bad |
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| 43:30 | and. Mhm. Well, just , can you, can you see |
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| 43:36 | I think that is not a good . A little hard to see |
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| 43:46 | It sounds like they're holding sea level . Well, yeah, that's that's |
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| 43:53 | you would have soon by looking at sand one great. The sand mud |
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| 44:01 | this is our general this green. can think it was a short face |
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| 44:06 | shore and that vertical cut boundaries. just pretend like it's sharp is a |
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| 44:19 | of wave energy. And see we change. Wave energy is function of |
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| 44:25 | . And so it stays at the vertical location as long as there's no |
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| 44:34 | of accommodation space. They'll change it notice here is rice and uh here |
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| 44:43 | ought to be different. And in , it should look like that. |
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| 44:51 | is what a force progression looks Okay. And notice both the forced |
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| 44:57 | and this normal regression suggests that a of this is episodic. There are |
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| 45:04 | of pro gradation, a little bit erosion. Pro gradation literally. And |
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| 45:10 | really far more each of these valuations . No, it's verified here for |
|
| 45:17 | long time. Yeah. Uh get here. It's a little harder to |
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| 45:25 | them. But we'll be looking at types of controls on the larger scale |
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| 45:34 | of deposition systems. Now, we're talking about things like sequence photography |
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| 45:40 | we're looking at changes in accommodation space sediment supply. And we're looking at |
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| 45:48 | dis conformity. These core relative These are this sounds like we're taking |
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| 45:54 | from the the architectural elements and in they just are larger scale architectural |
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| 46:03 | Okay, so we could look at assembly, different sequences defined by erosion |
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| 46:14 | boundary surfaces, timelines. And then could look within their uh with respect |
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| 46:21 | the definition systems that are characterized each these activities. So this is the |
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| 46:29 | picture. Doctor Bhattacharya did. We talk about this uh in his |
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| 46:35 | of course, uh what I'm I'm looking at this, I'm looking |
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| 46:42 | those packages of sediment that are being within those Hiestand tracks, transgressive most |
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| 46:53 | tracks. Okay, shit. Sorry I was Give me a little confused |
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| 47:06 | . It's 1, 1 more slide there. Yeah. So we say |
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| 47:12 | . Looking at this package of sediments are related. Could you also describe |
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| 47:17 | as programming? Programming? Yes. regressive synonyms. I see. So |
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| 47:24 | like two sides of the same Uh Yeah, it's just two different |
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| 47:28 | of looking at uh The transgression implies position of the coast. Regression implies |
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| 47:42 | changing the location of the coastal So, a pro grading system. |
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| 47:52 | , is a system with sediments by grating, moving seaward lucy the |
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| 48:01 | Well, man, see I Yeah. So for all purposes. |
|
| 48:12 | . Yeah. Yeah. Yeah. , let me just talk a little |
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| 48:21 | about things that have been happening over last 10 or 20 years and made |
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| 48:25 | life these here and uh you kind get things like uh gpr light are |
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| 48:33 | to go through each of these So uh let's look at uh the |
|
| 48:39 | linear dude dunes are notoriously difficult to . They're dry. They failed big |
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| 48:50 | and as a result linear do just they were described. Uh The internal |
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| 48:57 | have been argumentative are argued about for long time. Now we're able to |
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| 49:05 | into those things using GpR get much . Mhm. Idea of the types |
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| 49:12 | sedimentary structures that we could before. thing with barrier islands. Uh We |
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| 49:18 | look at the programming shore face barry . Yeah. Uh So you might |
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| 49:26 | look at the beach ridges but now can expand the beach ridges by looking |
|
| 49:31 | the climate force. Mattering migrating had . The biggest problem is we can't |
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| 49:38 | see the service Yet in some barrier . Over 50 of that package is |
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| 49:46 | by Thailand its pluses because of I laterally migrating in this. And so |
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| 49:55 | is really the go to process by we are studying many modern environments. |
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| 50:03 | in the process there's a great We are look at aspect of |
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| 50:09 | Uh huh. This is sometimes called GpR radar species. Uh So it's |
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| 50:19 | radar and she's one prescription interpretation. we've got to make that five different |
|
| 50:29 | . This is very similar. Would be doing in seismic interpretation? Uh |
|
| 50:35 | now we take this subdivided into We look at it in 3D |
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| 50:41 | And from that we can begin to the architectural levels. And so now |
|
| 50:48 | got a three dimensional geometry of what . We could only see in two |
|
| 50:55 | . Yeah, there's always been a between the modern and the ancient because |
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| 51:01 | tend to see the modern is a Matthew and our ability to look at |
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| 51:10 | environments in three dimensions is limited For the most part, two unusual |
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| 51:16 | surfaces, how deep and how many students should get out digging a |
|
| 51:22 | So it's not really official. This the new more in terms of looking |
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| 51:28 | modern definition of systems. The other we've had is that so many of |
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| 51:33 | best exposures on cliffs. And so von Sharia hasn't jumping off this. |
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| 51:40 | , on a rough sarah to say beginning to incorporate imagery taken uh contiguous |
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| 51:52 | , high resolution industry to give us sense of the lateral continuity because when |
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| 51:56 | look at ancient rocks, we tend focus on vertical section of measured section |
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| 52:04 | maybe one over here and then we to correlate, well, this is |
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| 52:08 | way of correlating almost inaccessible systems and drone photography now. Okay, |
|
| 52:19 | we're looking at the growth migrations. , you're looking at verte aerial photography |
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| 52:29 | leak photography. These all drones. , and we're using ground based |
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| 52:36 | So we're using both photos on gpr , drone photos, land photos, |
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| 52:47 | photos. There's all sorts of things using to be able to begin to |
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| 52:54 | both modern and ancient environments in three . Okay. There's also a lot |
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| 52:59 | stuff going on with tours. This really my specialty. So on to |
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| 53:04 | that there's more and more that we do with interpreting the environment of deposition |
|
| 53:13 | detailed imagery, uh, micro imagery . Uh, this particular one is |
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| 53:19 | public this year. Uh, we're looking at the decline annual deposits of |
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| 53:27 | laterally migrating point ball. Uh, is in the uh huh oil sands |
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| 53:37 | Alberta. Okay. Uh huh. water. The environments we're very poorly |
|
| 53:48 | before the time of side scan sonar we're just trying to come to a |
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| 53:54 | metric profiles. Okay. Mhm Side scope son are drained the ocean course |
|
| 54:01 | allowed us to view marine environments like non marine environment and both from large |
|
| 54:10 | and also things like uh looking at bars in rivers where again we, |
|
| 54:17 | had difficulty and really interpreting what's below water. Those vertical sections. |
|
| 54:26 | these are the signs here. Some at all. Uh, these are |
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| 54:34 | sections of the, they're looking at cars. Do okay, get probably |
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| 54:46 | single most important. Yeah, single most important. Uh huh |
|
| 54:57 | Concept that's improved our, certainly our of uh ancient rocks. This size |
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| 55:06 | jim apology. And so what we're is we are trying to look at |
|
| 55:12 | d sizes interpreted basically as a faces . Remember the faces tracks was a |
|
| 55:22 | time. And so we're looking for lots and so we go in and |
|
| 55:28 | draw a timeline maybe along there. what we find is this seemingly totally |
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| 55:37 | detail of the environment of deposition, faces track at the time there. |
|
| 55:45 | we have this tremendous ability to interpret resolution three D. Size in terms |
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| 55:55 | the geo morphology. And it's also a resurgence of interest in traditional geo |
|
| 56:03 | . How do we interpret the landforms coastlines and rivers, etc. Satellite |
|
| 56:12 | is also broadened our access to case . Okay. Uh there was a |
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| 56:20 | when you could count the number of studies of Delta's will run heat. |
|
| 56:29 | we've got out and the reason that have access to that is because we've |
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| 56:36 | hi detailed satellite imagery and we've got Satellite imagery going back into the |
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| 56:45 | So we can even look at how positional systems have changed within decades. |
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| 56:54 | here, for example, we're looking uh training base. So tremendous additional |
|
| 57:06 | . Yeah. Uh We continue to things like flumes to recreate a variety |
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| 57:15 | systems. And uh there's been a of the use of interpretation of jet |
|
| 57:24 | . This is Work that was done the mid-50s originally and mainly because of |
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| 57:32 | but other companies as well. Uh beginning to see the application of new |
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| 57:37 | studies in interpreting uh particularly deep sea . Okay. We also had analog |
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| 57:45 | like sandboxes where we can look at both the morphology and cross section of |
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| 57:55 | that's coming into the system. We use very detailed uh imagery for elevation |
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| 58:03 | look at the morphology of these uh studies. We can also look at |
|
| 58:10 | modelling continues to be improved. And of the things to point out is |
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| 58:20 | if you're going to do numerical modeling what you're trying to do is to |
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| 58:28 | a given set of observations. So want to be able to find us |
|
| 58:36 | . Uh huh. Well, in to model did us you need to |
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| 58:43 | what are the variables that were controlling distribution center? It's a lovely supply |
|
| 58:56 | but by knowing those and or knowing they affect sediment and then modifying |
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| 59:04 | you can create a model for your for your out drop. Okay. |
|
| 59:14 | we're using more and more geochemistry, little less photography using things like zircons |
|
| 59:23 | look at uh provenance studies. We're at optically stimulated luminescence to date |
|
| 59:33 | Uh So that with providence were no constrained to photography. Bless you. |
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| 59:42 | with oh sl we're no longer constrained LTD uh Carbon 14 center. So |
|
| 59:50 | just a lot of things that have literally during the course of time in |
|
| 59:55 | I've been teaching this course. I having to add which one of the |
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| 60:00 | that continues to go longer than I . Yeah. So let me get |
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| 60:04 | what in a sense is the introduction that you're uh this is the sequence |
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| 60:12 | topics that we've talked about today. And the topic of the exam one |
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| 60:18 | is the next Friday now on saturday or sunday morning, I will post |
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| 60:25 | study guide for that example. And uh we'll go on and do |
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| 60:32 | . Um We're not. Mhm. it'll be selfish. Uh The exam |
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| 60:42 | is basically um short essay, interpret photo interpreter diagram, make a |
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| 60:52 | we match things. And they were there will all come from my |
|
| 60:59 | There's nothing on the exam that is from the reading. It is it |
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| 61:04 | all be from the notes and it all be from the study topics that |
|
| 61:08 | I have high grade. Yeah. Next friday exact for our part nail |
|
| 61:21 | systems. The falling friday saturday we're to look me at. Very |
|
| 61:31 | Yeah. Now example wanted to technically not human but that's misleading because the |
|
| 61:44 | covered here is being applied. Yeah. So although I may not |
|
| 61:54 | the question about sedimentary structures per I will ask you about sentiment |
|
| 62:03 | This is this is not. Uh This is gonna be first uh |
|
| 62:10 | I'll there will be a question on genesis. Uh Maybe two. But |
|
| 62:16 | what you'll see is when I give the topics and I genesis will be |
|
| 62:21 | of the topics of study guide. huh. It and usually I do |
|
| 62:25 | by topic. So the genesis follicles . Well, I will tell you |
|
| 62:33 | how many points on the example. more or less subdivided based on time |
|
| 62:39 | but I'll modify basic methods support. within that you might see on |
|
| 62:46 | Eight questions, one of which is digests or two of which. So |
|
| 62:51 | tells you you're not likely to have than one question about texas. |
|
| 62:59 | Alright. The last exam uh is the final. And so what I |
|
| 63:08 | is there's about a third of it deal with earlier topics And about 2/3 |
|
| 63:18 | last song. And there are certain for I can relate things between the |
|
| 63:25 | different exams comparing different environments. For , that arguably I couldn't do. |
|
| 63:34 | . Again, the study guide will your guide in terms of how you |
|
| 63:39 | . Okay. Okay. So the thing we're gonna do before we take |
|
| 63:42 | break is there's going to be a . Uh So here is heights sedimentary |
|
| 63:54 | . Does does anybody recognize this You give a name to destruction with |
|
| 64:04 | that again? Okay. It's fading stratification. Could you tell me |
|
| 64:12 | kind of prosperity fication? Yeah. swelling. And then we'll talk about |
|
| 64:21 | distinction. But basically we're looking at this point that except swim. Um |
|
| 64:31 | so that's gonna occur at the base wave base. So it's a wave |
|
| 64:39 | sedimentary structures relatively deep compared to the itself. So usually we talk about |
|
| 64:46 | storm Republics as we'll see there are exceptions to that. But this is |
|
| 64:53 | improvement sediment restructure that we completely ignored walked off uh for decades And that's |
|
| 65:05 | good friend, 1950s described it as because it was just didn't make |
|
| 65:12 | didn't fit our models of cross And so we ignored it until |
|
| 65:19 | uh in the mid to late 70s began to reinterpret then it was everyone |
|
| 65:26 | saw. And part is because we looking for and if you look forward |
|
| 65:32 | will find in fact you'll find it when it's not there, which is |
|
| 65:37 | of the problem. And I'll try really, let's say it again. |
|
| 65:43 | is this picture of? Well, , see how this hung up |
|
| 65:49 | building this comically structured here. If look at it right here, it's |
|
| 65:58 | is here. Um that's sent here . That's sticker here, man, |
|
| 66:07 | get the same thank you pension sweat these beds basically forming by vertical |
|
| 66:19 | They start with a plain bed and for pilots and Phil and swim. |
|
| 66:25 | talk more about that later. But is a type of sediment construction. |
|
| 66:33 | is very important because it is fairly and location specific, but it's one |
|
| 66:43 | we didn't recognize so long as Okay, this is awful constructed. |
|
| 66:50 | you give me a name for this drop press because Cross Stratification. Say |
|
| 66:58 | three times less. Yeah. Uh all dipping in the same uh in |
|
| 67:16 | sense that this is coming towards I say towards man coming in this |
|
| 67:31 | and failed for trump? How many you have trump? Mhm. Something |
|
| 67:40 | learn. Okay. Uh So where you think you would find this |
|
| 67:45 | What environment do you think this? process product was full short uh short |
|
| 67:58 | . Okay. It's a possibility. What this requires are ubiquitous dunes. |
|
| 68:08 | The reality is it's for the longest lumia power because I do know is |
|
| 68:17 | it cross cross stratification are typical in . It turns out that you're right |
|
| 68:25 | this is biography and it's got marine forces. And so there is an |
|
| 68:32 | fictions within the shortenings. We have trough clusters. Check so again the |
|
| 68:42 | was fluid. But the problem is it really was describing our three dimension |
|
| 68:52 | . What about this? Give you hit. Let's don't sense this. |
|
| 68:58 | is a particular type of Betty, coward. I'm not really here. |
|
| 69:10 | the alternation layers of sand. There's was called Mix of it having realistic |
|
| 69:20 | . Uh And you can see here there are little pockets for the biscuit |
|
| 69:26 | , isolated ripple. Other cases no and wavy layers. This is sometimes |
|
| 69:33 | bedding, wow particular bedding please. bedding. Yeah. Where do you |
|
| 69:41 | that type of betting occurs? How you have to work forever? Remember |
|
| 69:50 | again this richard, it's the darker my mother for much Lauren that so |
|
| 70:03 | they happen to see it. So we're beginning to see an environment |
|
| 70:09 | it is we have altered in deficit and like the short intervals attack where |
|
| 70:20 | . What's the scale of this is Oh, okay. Yeah. I |
|
| 70:27 | 14 to 20 kinds of scales ranging my car keys. Who can someone |
|
| 70:33 | millimeters to a person. Uh That's huge important question and often disappeared. |
|
| 70:39 | I'm also big independence nickels and Uh huh. So where do you |
|
| 70:44 | this might be? Where do you pleasure bedding weaving in particular, betting |
|
| 70:50 | , prolific or mixed, sending micro Marie. What is most typical in |
|
| 71:01 | snacks? So this is the almost signature picture photography positive. The problem |
|
| 71:12 | there's deep water forms exist. So you're description of the process is |
|
| 71:22 | but you're placing that process in the equivalent environment is wrong. This is |
|
| 71:29 | leading on a some region or someone thinks, okay, so the processes |
|
| 71:36 | assemblages of sedimentary structures can be similar a lot of different parts. |
|
| 71:44 | how about here? Uh huh. just say let's just call it big |
|
| 71:50 | person for escape. Uh huh. how do you think this? Uh |
|
| 72:07 | not gonna tell you this does separate set of information on this set of |
|
| 72:14 | . So this final stop this. . What? Okay. Yeah. |
|
| 72:31 | the longest while Yeah, that's how knew for the longest part. This |
|
| 72:38 | of structure is interpreted as the only , because the only thing we had |
|
| 72:46 | vision of that had that big a fits. But as we began to |
|
| 72:51 | at side scan sonar, we realized there are large scale sand waves forming |
|
| 72:57 | entitled environments and in current environments in ocean particularly accountant show. And you |
|
| 73:03 | not what this is. Well, is a circus is full of |
|
| 73:10 | So it's clearly Marie minutes to look here. You begin to see packaging |
|
| 73:18 | four sets that as we look more says title in order to So that's |
|
| 73:27 | is a damaging surface. These are the service and we're going to use |
|
| 73:33 | bounding surfaces to recreate set in this ? It's actually a uh title marine |
|
| 73:42 | straight in them. I see. , last last. Uh huh. |
|
| 73:48 | again you've got Uh huh. Mhm . A Yeah, boundary over |
|
| 73:59 | A a boundary surface here. Mm . My parents not to. All |
|
| 74:19 | . Yeah. Here. Okay. see the cross stratification. So first |
|
| 74:32 | all, that's that's just answer this . What's the failure flow direction share |
|
| 74:38 | us? Right. Mr it looks to do that again. That's two |
|
| 74:46 | ways. Looks like um Well, scour and what is the technique? |
|
| 75:00 | what what is the evidence that foreign ? Well, you said two different |
|
| 75:08 | . Well, yeah, it looks you can see evidence for one way |
|
| 75:12 | another way to buy your way. no, suggest. Therefore high preaching |
|
| 75:28 | where part of the strategy suggest therefore you said you see it Well. |
|
| 75:38 | ones below. But now I'm looking little closer to me. Maybe |
|
| 75:43 | All right. I can't. There's shower here. I don't see any |
|
| 75:51 | . Same thing here. Take a and see how this is laughing. |
|
| 75:57 | this is growing in this direction, death. So, I don't see |
|
| 76:05 | evidence by directions. This is actually direction. So, would that be |
|
| 76:13 | on lapping the dP to the These are Yes. And that is |
|
| 76:24 | long acting out there. Although it's it's curving for the package. |
|
| 76:32 | okay. Uh It turns out the is towards Yeah. And this is |
|
| 76:41 | feature of a sigh click step. it's an upper floor regime is like |
|
| 76:48 | huge an issue where the bed forms upstream. This that form or rather |
|
| 76:59 | sediment from structure has really only been the last three or 4 years. |
|
| 77:07 | , we're now beginning to see how are some large scale structures they are |
|
| 77:16 | sometimes in rivers and in deltas, mainly in deep sea environments where we |
|
| 77:23 | upper floor regime. Supercritical sedimentary Supercritical florida, where the bed forms |
|
| 77:29 | Margaret street. It was just now to find field examples of these. |
|
| 77:38 | the reality is we we see what look for and we interpret what we |
|
| 77:43 | based on what we've seen in the . And so the purpose of talking |
|
| 77:49 | these is that what we're really trying do is make that link between structure |
|
| 77:57 | process. Once you've done that, we start working back to the environment |
|
| 78:04 | . Okay? Um tonight, let's cut the recording at this point and |
|
| 78:12 | take a break |
|
