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Author | Topic: Formations really do match detailed lab expts of sorting under rapid currents | |||||||||||||||||||||||
edge Member (Idle past 1736 days) Posts: 4696 From: Colorado, USA Joined: |
quote: The length of Nevins' section is not material. However, his velocities are interesting. How are these calculated and in what direction are they? Remember that hydrodynamic sorting causes finer grained sediments to be deposited in a downstream direction.
quote: Actually, I don't. At least not in as simplistic a manner as you seem to be suggesting. Now you really need to question Nevins more carefully. Why does the sorting indicated an opposite direction of flow to Nevins' current?
quote: If you knew anything about geology you would understand that a bed is not a facies. You would also understand that three facies for the Tonto Group is a gross simplification of the real system that, unfortunately, makes it possible for Nevins to make wild extrapolations of the data.
quote: Then you understand that you have much to learn.
quote: Back to the classroom for you!
quote: Your posts have not shown this.
quote: Neither. The Tonto is a group of formations. The Mauv is a formation. The Mauv is made up of hundreds(?) of beds. A bed is a distinct layer with discontinuities of some kind at both upper and lower bounds. A lamination would appear within a bed and probably is the closest thing here to an actual time-bound unit. This is off the top of my head, of course and someone may have a more rigorous definition for you. You have to remember that formations are simply convenient names and may include many rock types and/or depositional facies. When we say the Mauv is a limestone, this is a generalization and it probably includes several other rock types. This has to be done or else details would swamp anyones effortst to understand them and the rocks would become impossible to map. Another simplification that Nevins employs (and must employ) is that the transgression is a nice orderly march across the continent. This is not the case. In fact, there are many sub-regressions and sub-trangressions (for lack of a better word). This is why we have feathered contacts on vertical sections and terms such as 'tongue' (primitive but very descriptive) in describing some formations. This is a detail, but it makes all of his calculations virtually meaningless.
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Tranquility Base Inactive Member |
Mark24
The sorting happens at multiple resolutions. You get a global (ie large-scale) sorting over 800 km horizontally and 1000 vertical feet and a local stratum level effect as well. It's not a pefect sorting across the entire 1000 feet. There are imperfections and they get sorted locally.
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Tranquility Base Inactive Member |
Edge
Who is Nevins? It rings a bell from our previous chats. Did Austin publish creaitonist material as Nevin's at one point? I think we all know his real name is Austin and that is what he publishes under these days too. The effect that Berthault, Julien et al find empirically is anti-intuitive. You get course stuff downstream first becasue the bed builds up horizontally and vertically at the same time and under rapid flow the fine stuff isn't deposited at all until the flow rate has decreased. The key issue is flow rate changes as well as flow rate at all. I thought it would be as you said as well but this is not what is found in the flume studies done at Colorado State. The leading edge (furthest from the source area) is coarse. Calling the Mauv a formaiton is fine by definition but may be a misnomer for creationists if we believe that it was formed at the same time as the Bright Angel and Tapeats. As a layman geologists I would think that creaitonists would view anything formed simultaneously to be a formation and the sorting by material as facies no matter how big. Because in the past, and perhpas still, you guys have had such a bias with the law of superposition it wouldn't occur to yuo to call the Tonto a formaiton. For us it is becasue it all formed in one dynamic. Having said all that, I can't speak for the professional creationist geologists. I'm only a humble biophysicist. I am fully aware that a 300 foot facies is a simplification but in our view of how they formed, a useful one. I'm fully aware that these formaitons come and go horizontally and are quite complex. Tonguing etc does not make any of Austin's clacs pointless. As a physicists we can do all sort of calcualtions that get the correct ballpark result. A spherical horse travelling at 20 km/hr will take 4 hours to travel 80 km regardelss of the anatomical simplificaiton made. Austin's results will be ballpark correct as long as, within the resolution he is working, he hasn't made any blunders. There is no need to require higher resolution to work out the basic flow rates. Just use Rubin et als empirical charts.
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edge Member (Idle past 1736 days) Posts: 4696 From: Colorado, USA Joined: |
quote: Perhaps a bit off topic, but why do we find NO such imperfections in the fossil sequence, then? Surely, if we can find gravels mixed shales, then we should be able to find at least one trout with the trilobites...
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TrueCreation Inactive Member |
"When did those shells find time to grow? Where will you get the dissolved calcium, and what will you do with the emitted carbon dioxide, from either their growth or from chemical precipitation? "General Flood Topic", post 17 and following, please."
--I partially considered the limestones and such marine depositions would have a source which was pre-flood. I haven't seen data which would allow me to see it feasible to have various chalk & limestone strata to be deposited. Of course this is due to my lack of data on their geography. ------------------
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Tranquility Base Inactive Member |
Edge
I suspect trout were better swimmers than trilobites but I follow your point.
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edge Member (Idle past 1736 days) Posts: 4696 From: Colorado, USA Joined: |
quote: I was just pointing out the uncertainty of knowing what Austin publishes.... It's so confusing. By the way, he DID lie about his use of Nevins, so you have to wonder.
quote: To someone not trained in the field, perhaps. To someone who has actually worked in the field there is nothing counter-intuitive here.
quote: Actually, as I remember, all of Berhtaults sediments were sand. Now, I challenge you to look at any sequence in the field and tell me that the coarser sediments are farther away from the source. You are going to have to explain, in that case why shales are offshore. I am begining to see your problem here. You are taking a bench scale experiment and extending the results to regional geology. Big mistake, TB.
quote: Once again, I suggest you learn some geology before you begin to reinterpret the literature.
quote: Well, if there was a flood you could do that. The problem is that there is no correlatable unit that one can call a biblical flood deposit.
quote: Superposition has been abused and misapplied by many, but it still stands.
quote: They have a lot to answer for, but they would rather that you just read their tracts and send money. You will almost never find them here helping you out, because they know that they will be made to look like fools. So, they send you out here into the fray.
quote: Sure it does. If the shoreline got to Grants, for instance, and then went back to Las Vegas, Austin has to cover the distance 4 times and his calculations are meaningless.
quote: Yes, these are all measurable quantities. Now, how many times did the shoreline backtrack? Any ideas?
quote: But he has. He has also not accounted for the current directions as you have previously mentioned ad nauseum. As I recall he needs to move a lot of water in the opposite direction of your transgression.
quote: Of course. Let's ignore the details that Austin/Nevins finds to be distasteful.
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Tranquility Base Inactive Member |
Edge writes: To someone not trained in the field, perhaps. To someone who has actually worked in the field there is nothing counter-intuitive here. Since we both find it strange that coarse particles are found at the far edge in flume experiments then we both find it anti-intuative.
Edge writes: You are going to have to explain, in that case why shales are offshore. Yes, I noticed that inconsistency too. The beach of course is not quite the right model for a catastrophic marine transgression where the flow would be in one direction (until regression) rather than waves and rips.
Edge writes: Well, if there was a flood you could do that. The problem is that there is no correlatable unit that one can call a biblical flood deposit. We're quite happy to work with a half dozen or so major marine formations for the flood with intervenning freshwater flooding. You keep forgetting we agree with your second order sea-level curves.
Edge writes: Superposition has been abused and misapplied by many, but it still stands. As Berthault discovered there never was a proper mechanistic theory of strata and facies generation. It was all assumed from empirical 'postulates' that only apply in near zero flow.
Edge writes: Now, how many times did the shoreline backtrack? These are important empirical questions that observation can answer but they do not impinge on the big question of how the strata got there. For you reversing was slow for us it was fast. It is not a point of distinguishment.
Edge writes: As I recall he needs to move a lot of water in the opposite direction of your transgression. Just as mainstream you have a regression after a transgression so do we! What's the surprise there?
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Admin Director Posts: 13046 From: EvC Forum Joined: Member Rating: 2.7 |
There has been some excellent discussion in this thread, but I have a small request. There's no violation of the guidelines involved, not even close, kudos to everyone, but I wonder if it might be possible to lessen the superior "look down your nose" comments. Thanks.
------------------ --EvC Forum Administrator
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edge Member (Idle past 1736 days) Posts: 4696 From: Colorado, USA Joined: |
quote: I don't find it anti-intuitive at all. I can think of a number of reasons for this. However, these experiments do not apply directly to a depositional basin. They represent only what might happen on a sandy beach.
quote: As I have been suggesting all along.
quote: And this has what to do with superposition. Even in Berthault's experiments superposition was not violated.
quote: Then you point regarding Austin/Nevins calculations was not necessary.
quote: I'm not sure if you are avoiding my point or just didn't get it. Austin has to do this DURING your transgression, not after.
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edge Member (Idle past 1736 days) Posts: 4696 From: Colorado, USA Joined: |
quote: I regret this. I was simply trying to (tactfully at first) suggest that one learn a bit about the subject before rejecting old work and expounding new theories based on incomplete knowledge. Apparently, my strategy has failed.
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Tranquility Base Inactive Member |
Edge
Edge writes: They represent only what might happen on a sandy beach. That's not waht the flume expereiments suggest. The flume experiments simply show what sort of deposition patterns one gets when one has current flow. Very general.
Edge writes: As I have been suggesting all along. Yes sop the beach may not be a great model but the flume experiments are together with Rubin's field measurements are.
Edge writes: And this has what to do with superposition. Even in Berthault's experiments superposition was not violated. I disagree. Some of the downstream lowest layers can form after the upstream upeer layers and yet the layers are traceable across the entire length of deposition. Have you ssen the Berthaults video of mainstream Julien's expereiments at Colorado State? It has to be seen to be believed. I still get the feeling yuo don't quite follow what is hown in these expereimetns since it proves beyond doubt that superpositon is violated for the case of sediment despotited under flow. Of course at point X superpositon applies. Go to point Y = X + 100 metres and layer 10 could have formed before layer 3 at X. I have seen it with my eyes in 20 minutes of footage.
Edge writes: Then you point regarding Austin/Nevins calculations was not necessary. Not really, the precise mechanism was interesting enough for the flum expereiments to be performed at Colorado State by Julien. And it all depends. What do you, or mainstream GC stratigrpahy in general, believe? Was some of the Muav laid before some of the Tapeats?
Edge writes: I'm not sure if you are avoiding my point or just didn't get it. Austin has to do this DURING your transgression, not after. Explain please. Austin has the current going from W to E during deposition. Do you disagree with that? [This message has been edited by Tranquility Base, 12-07-2002]
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Tranquility Base Inactive Member |
Edge
I'm rejecting nothing. It's Austin, Berthault and mainstreamers like Julien and Rubin's data that suggest the reinterpretaiton. You just find it easier to fight my background than the arguements.
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funkmasterfreaky Inactive Member |
Edge,
quote: Isn't this how the most significant discoveries come about in science? Isn't it a scientist who decides the current analysis of the data is flawed that usually makes a real breakthrough? I just watched a beautiful mind again the other night seems John Nash didn't seem to keen on following along with what everyone else thought. Innovation< imagination, this is where the discovery is made. Would we ever learn anything new if everyone just took what we had and stuck with that? There are different types of people needed to advance science. You need the imaginative people who run off and come up with ideas. You need people to verify and discredit these ideas. Otherwise it will get out of control. So neither type is more intelligent they just have a different role. Why is someone condemned for using their imagination to make discoveries? Their role is just as significant as the mainstream scientist who just regurgitates and critiques. I know I'm not involved in this thread I just was thinking about this as I caught up on what's going on here. ------------------saved by grace
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wehappyfew Inactive Member |
I think it might help to share the videos and Creationist tracks you have been relying on, TB.
Here are some links that might be similar to what you have been referring to: http://www.geology.ref.ac/...hault/fusion/stratification.htm http://www.geology.ref.ac/berthault/fusion/new-approach.htm
TB writes:
What do your paleocurrent indicators say about that? I thought you said all paleocurrents point to the southwest in N. America? If the depositional current is coming from the west, then the whole model falls apart - the source of the sediments is now downcurrent from their resting place. Do Julien's flume experiments show conglomerates, then sands, then shales flowing against the current (back to the west)? Austin has the current going from W to E during deposition. Do you disagree with that? I think edge is constrained by an expectation that the flow regime modeled for the Flood should bear some resemblance to what is physically possible. If you look at the drawing in the second link above, you will see that Flood waters advancing along the surface from the West to the East, with a return flow along the bottom back to the West that carries the sediment into the Tonto Group strata. At least this model has the currents going in the right direction.But if you can't see the problem this model has, well... we have a lot more work to do.
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