TEMPORARY: So how did the GC (Geological Column) get laid down from a mainstream POV?

This is a continuation of the original 'So how did the GC . . . ' thread that presumably Percy will attach to the end of the old thread once it is fully working again.Wehappyfew, I agree that Lyellian features are superimposed on the epeiric sea beds (ie the beds deposited as seas 'transgressed' and 'regressed' onto much of the area of the continents).I take your points on continental shelves being flat. I'm aware of El Capitan etc but I still think the vast majority of, eg the marine Grand Canyon area beds, appear to be, perhaps not too flat (although I would love to see cross sections compared of modern vs epeiric), but too undisturbed. One can follow the flat interfaces with only very little ups and downs. Much of these beds do not look like marine habitats as supported by the mainstream comment I cited. Even the marine burrowing looks more like escape burrows becasue the sediments are not mixed throughout the regions near the burrows indicating that these burrows were created suddenly in new sediments and then it ceased (we know why).Both of our arguements are at extremes and the data seems to be just compatible with both IMO although of course I beleive you are stretching it and you believe I am stretching it!

​

[This message has been edited by Tranquility Base, 05-27-2002]

I have now found mainstream sources which state categorically that much of the sediments on the continents were generated by epeiric seas (transgressions of sea onto land). We all of course knew this was true becasue how else do vast marine beds form on land!My sources at this point are citaitons from lecture notes on the web from mainstream geology courses. I will ultimately find peer reviewed sources on this but here are the excertps, and web sites of, from some mainstream geology courses on origin of the geological column:

quote:

---

" . . . the large scale inland seas formed during ancient episodes of high sea level are termed epeiric seas; these deposited the rock record of much of the Paleozoic and Mesozoic Eras."
http://www.blinncol.edu/brazos/natscience/ajulson/Hist3.html

​

"Much of the sedimentary rock record of the Paleozoic and Mesozoic Eras were deposited during these periods of marine inundation."

​

http://courses.unt.edu/hwilliams/GEOL_3020/exam1review.htm

​

"Also during this time, shallow seas called epeiric seas covered much of the landmass of North America. Sediment accumulated in these seas and eventually became lithified into sedimentary rocks. These sets of distinctive rock layers representing the deposition of sediment into epeiric seas are called cratonic sequences. Geologists can determine which sea the sediment was deposited in by examining the characteristics of the rocks in each sequence. In North America, geologists have found six primary cratonic sequences Sauk, Tippecanoe, Kaskaskia, Absaroka, Zuni, and Tejas. The Epeiric Sea in which the sediment for each sequence was deposited bears the same name. For example, the rocks of the Sauk-sequence are from sediment deposited into the Sauk Sea."

​

http://www.geology.iupui.edu/Academics/CLASSES/G119/ThePlotandSetting.htm

---

The first lecturer goes on to point out that these layers were generated gradually of course but my point here is simply that 'much' of the Cambrian to Cretaceous was formed by depositons from these seas not as river deltas etc although I agree that there are Lyellian features superimposed on these beds. In any case it is clear that the majority of layering from Cambrian to Cretateous in North America at least is due to transgressions and regressions of the sea.And as I said, we all knew this although I find that mainstream geolgoists and textbooks emphasize the smaller Lyellian features on some occassions completely neglecting to mention the major role played by the epeiric seas. Most continental formations are marine so it is no surprise.I will state it as such: much of the continental geological column was laid down by epeiric seas. The key word that might be new for some is 'much'.

​

[This message has been edited by Tranquility Base, 05-27-2002]

Joe, you were wondering about my conceptions/misconceptions about sea-floor spreading etc. Yes, thanks. I now understand that the sea-floor spreading didn't fold the sea floor necessarily (or at all) but rather it is the build up of new sea floor ridges themselves that caused the sea level rises.My thought that you also commented on that I called 'delayed subduction' was just me trying to work out what caused the regressions. I'm now aware that mountain building on continents could lead to sea level drops. Having said that, now that I've seen the graphs of actaul sea-level vs time over the last 500 million years (see Hamblin, Christiansen & Hamblin for example) I am really wondering whether the idea of 'delayed' subduction is not a bad one (and might be a mainstream one). The graphs vs time (extracted from the geological record) show gradually increasing sea levels (transgression) with a rapid initial gradient that then decreases and levels of. Then the sea-level suddenly drops (regression). The graphs actually look exactly like a charging/discharging capcitor (for those into electronics ) - it's empirically an asymptotic approach to 'full' (1-e^-kt) and then a rapid exponential drop (e^-kt). Anyway, so the idea is that the sea-floor spreading is limited by the mass of the build up of magma sitting on top. Because it hardens it can then also exert pressure transversely on the oceanic plates at the mid-oceanic ridge directed along the plates. This transverse pressure ultimately is transmitted to the oceanic/continental plate boundaries, builds up and is released as the oceanic plates overcome a frictional threshold and subduct under the continental plates 'rapidly', relative to the initial build up, allowing the sea-floor to properly spread and so you get the sea-level drop. And hence you get the classic sea-level curve. That's my theory coming as an outsider anyway. I have checked the literature now on transgressions/regressions and have note a paucity of explanations for the 'sudden' sea-level drops (other than mountain building).

​

[This message has been edited by Tranquility Base, 05-27-2002]

Yes, Joe I'm mainly talking the 1st order curves. I'm not denying that there will be local effects and smaller global effects superimposed on this. But like any dynamical model it will have a central mechanism and my hypothesis is this idea of delayed subduction.It's probably complete garbage but it might even be part of the mainstream thinking - I'm just thinking aloud. I just did a search on the web and even came up with one hit to 'delayed subducton' and am currently evaluating its relevance. I agree I'm moving into new teritory here for me but physicists have a history of that of course!I don't deny that all things being equal the oceanic plates will dive under due to their density but one could imagine that density aside there will be frictional issues and that the relatively rapid sea-level drops could be due to a frictional theshold that gets periodically overwhelmed (cf earthquakes).PS 1 - I can't access your link.
PS 2 - I take your point about 'delayed'. I'm using it because the subduction is delayed relative to the spreading and sea level rise. From the normal point of view I agree it's more like 'forced subduction'. The 'delay' comes from the (do I really need to say hypothetical?) frictional threshold.

​

[This message has been edited by Tranquility Base, 05-28-2002]

Thanks Edge, I was actually feeling that too (Lyellian vs epieric seas). I can appreciate that(i) I'm not saying anything controversial
(ii) except that I need a better word than LyellianPerhaps I simply mean that the geological column can be considered to have been generated by a series of epeiric sea transgressions/regressions followed by primarily non-marine erosional processes that generated the smaller component of sediments.From the non-mainstream POV we would say that the flood surges generated the continental epeiric sea layers (which is much of the geological column). Each regression was followed by erosion of these soft layers via fresh water. At the end of the flood we have the final regression generating, eg Grand Canyon etc, out of soft layers, and then 4500 years of Lyellian gradualism. That is my current view of it but I would prefer it didn't side track us from the mainstream view in this thread. Debate it with me in the 'rapid layers' thread if you want.Is there something wrong with talking about marine strata on continents? Is there a better way to put it? Wait - I said that 'most continetal formations are marine'. I was hoping that that was not ambiguous - I meant: most formations on continents are actually marine. Is there a better way to say this?

​

[This message has been edited by Tranquility Base, 05-28-2002]

Edge, my main point is that much of the geological column was laid down as marine beds on land. We would be silly not to point this out as subscibers to flood geology and take some heart from it!Three comments on your point about the Grand Canyon etc being cut out from lithified sediments:
(i) We presume this was one of the later episodes of the 400 day event.
(ii) Mt St Helens displays sharp canyons cut out of soft layers (and yes there are of course scale differences here).
(iii) It's possible that a lot of the canyon collapsed due to it being soft and that 4500 years of Lyellian processes has worn down the collapsed edges through both erosion and landslides.

​

[This message has been edited by Tranquility Base, 05-29-2002]

Wehappy, thanks for your offers of help. I'll accept it gladly. At the same time don't write me of too quickly either!From the first order sea level curves it does seem to me that the continents have spent a lot of time underwater. Having said that the main piont for me is that most of the geological column on land is marine regardless of how long it took. If anything we would totally agree with you on the orogenic pulses - that much of the geological column tells a story of uninterputed deposition for thousands of vertical feet at a time (you would probably not say 1000s of feet I suspect ).I'll agree that your scenario for recording only the undisturbed sediments rather than than the actual sea floors is possible. But when the raw data tells the story of continuous parallel layering Occam's razor's first port of call is surely that the layering was continuous and rapid due to the lack of evidence of long-term habitation. Your scenaruio is possible but the dat better fits a sinlge 'storm' than many (1000s? of) storms.PS - I've read quite a lot on the early geolgoists. It is fascinating stuff and I'm not just in it for the flood geolgoy. I like the science of it too. I'm a fan of Hutton, Smith, Lyell, Cuvier, Mantell and Buckland etc. I have my own ideas of why the 'creationist' geologists failed to see the flood in the strata. The main reason IMO was that no-one expected that you could get layering from rapid deposition - they all thought it only happened due to cyclical seasonal events. The majority at least hadn't thought much about hydrodynamic sorting as a mechanism for rapid layering. The other aspect is that no-one knew about continental drift, the sea-level cycles and the possibility of tectonically induced flood surges. This is all a part of modern flood geology and IMO it is a valid sceanrio.

​

[This message has been edited by Tranquility Base, 05-29-2002]

Joe - go write those proposals.I've read about 5 different accounts of the uniform/catastoph debates (eg in Hallam's 'Great Geological Conroversies' etc). I stand by my two points above at this satge. It seemed that all that Lyell et al needed to do was show that there were compelling potential modern counterparts to fromaitons in the geolgoical column and the creationists of that day gave in. Modern flood geology can easily accomodate all of the basic features of the geological column:1. The vast marine strata (on land) formed by transgressions
2. Large non-marine layered beds
3. Local miscellaneous non-marine formationsIMO, mainstream geology only explains #3 well.

​

[This message has been edited by Tranquility Base, 05-29-2002]

Edge, I agree that the walls would have been weak and fallen and I agree that scale issues make MSH only potentially interesting. I wont agree it is a 'silly' - it is still a good model system.Let's try and picture in our minds what would have happened if my scenario were true.* A gully would be carved out by rushing regressions of waters. The walls would collapse near the centre of the gulley.
* Moving water would transport the collapsed walls down stream.
* Then more walls would collapse etc becasue the debris was no longer supporting the walls. This would iterate.
* At some point, as the flow decreased, enough debris would remain for long enough to hold up the walls long enough to not collapse. The flow, gradually settling to modern levels could ultimately remove the debris without further risk of major collapsing.I think you have to ask yourself what the Grand Canyon would look like in your opinion if it were carved out of soft sediments. Surely at some point you reach non-collapsed walls! You could argue that we should see partially collapsed walls or walls with curved layers but it's also possible, that due to criticality, that the walls would shear off over time ultimately leaving sharp walls with non-curved strata. And flow can move the debris. This would be difficult to deterministically simulate but not impossible. I don't think it's somehting you can 'pronounce' from intuition. We have no perfectly analogous model for this as you yourself pointed out.

Edge, my point about the epeiric seas is that mainstream geolgoists, and sedimentology texts in particular, tend to emphasize that the geological column got here by modern day observed means. But in fact, the majority of the column got here by epeiric seas which I have quoted mainstream researchers saying do not have anything like modern counterparts (in size). That is not necesarily a problem (the earth's modes change due to tectnoic action - fine) and that is why it is non-controversial for you.A little bit of convtroversy comes from the following. I have recently read from cover to cover three 'Origin of Sedimentary Rock' books and the sedimentary/geological column sections of probably a half dozen university geology books and they almost invariably do not point out clearly that most of the geolgoical column was formed by epeiric seas.It is absolutely undeniable that 95% of the text in any of these books covers the miscellaneous local environments (eolian, glacial, fluvial, deltaic, lacustrine etc). A tiny proportion of the text will be spent telling us that most of the geological column was formed in marine neritic (?) or shelf environments on land due to multiple transgressions of the sea and showinf us wher ethese sediments are. To me that is a little disturbing and maybe you can tell me why this disproportionately small amount of time is spent on such a large proportion of the geological column? My (non-cynical) guess: because there are so many different non-shelf enviornments? Fair enough but then why the (typical but not always) silence in the geolgoical column sections on epeiric seas? I personally think you guys don't like admitting that much of the geolgoical column was generated by marine transgressions onto land but to each his own.I'll tell you one consequence of this. The naive layman (as I was and am becoming less and less) walks away with the impression that the layers around the world were all generated in swamps, river deltas and lakes. And I'm still convinced that the paelocurrents tell a story of rapid transgressions not your placid epeiric seas.If you think your 'each storm sheared of the seas floor habitat parallel with a current layer' is better than a rapid single continuous layering for marine beds - go ahead. I personally think that our scenariuo wins hands down on that. Your scenario is the one that needs the evidence of the 1000s of storms not ours! We don't see evidence of the 1000s of storms (via a lack of uneven unconfromities) and so we say the data talks of continuous deposition. The paleocurrent data even speask of long term rapid flow! It's your scenario which reads something into the data which is not necessarily there. You believe in your scenario simply becasue the long-age paradigm requires it. In this instance it is our scenario which is more natural.If you accept rapid deposition of layers - great. I have mainstream refs I have already posted here showing that, not that long ago, this was not beleived by the majority. And rapid layering clearly occurrs via hydrodynamic sorting - why do you say it doesn't?Why do I point out the eperic seas? I personally believe that if epeiric seas had been understood back in Lyell's time that the creationists would have stood a better chance than they did then.

​

[This message has been edited by Tranquility Base, 05-29-2002]

Edge you keep having a go at our Mt St Helen's model becasue we can't orchestrate a full scale Grand Canyon event for you to see today and then you say:

quote:

---

"Saturated sediments do not stand."

---

It clearly is an issue of quantitative extent. Mt St Helen's proves that you can get 100 foot high sharp canyons from month old sediments! But you prefer to use your experiences in the sand pit ahead of a very good model system that is tainted by creationism.PS - tell me more about the fracture systems.

​

[This message has been edited by Tranquility Base, 05-29-2002]

Philip, my point about the origin of the geological column is simply that, contrary to popular misconception, the mainstream view actually is that most of the geological column on land was deposited as encroaching shallow seas (these are called 'epeiric' seas) that came and went on multiple occasions. This is not really any shock to anyone becasue most of the sedimentary rocks on land are marine formations. In between these incursions of the sea are typically large freshwater deposits. Then on top of these we see evidence of more local deposition typically by rivers. At the top of the geoogical column we see a lot of evidence of glacial melting.So we see the vast marine layers on land as rapid incursions of the sea during the flood. Scientifically we thnk these incursions were rapid (not gradual as the mainstream view would have) because of the water flow speed data that is revealed by studying the grain, ripple and fossil orientations. The large freshwater deposits we think are due to the catastrophic rain and are not readily explained by mainstream environments. The local depositons we would say are the drainage of freshwater cutting into newly created soft sediments (although we acknowledgethat these also could have been creaed over eons of time carving out feautres from hard sediments).After several cycles of (i) marine surges, (ii) catastrophic freshwater torrents and (iii) local deposition due to final drainage the flood subsides, carving Grand Canyon etc out of soft sediments in the last cycle. The flood was presumably tectonically generated (ie due to sea-floor spreading etc) and the vast quantity of volcanic ash in the atmosphere generates a nuclear winter scenario and thus the ice age(s). The melting of these huge glaciers as the ash falls out creates the final large freshwater deposits on earth (much of the 'tertiary' gelogical period).Our scenario and viewpoint of the mainstream scenario goes something like that although I am not myself a flood geologist or any other sort of geolgoist.

​

[This message has been edited by Tranquility Base, 05-30-2002]

I would be interested to see a careful comparison of the layering in ancient epeiric sea formations vs modern shelves. I have read that:(i) The modern shleves are not at all comaprable in size
(ii) The ancient beds are too undisturbed (and maybe? too flat
(iii) The measured paleocurrents are differnet in character

quote:

---

"It is difficult to use modern shelf seas as analogues for their ancient counter parts for two reasons. First, at the present time, the earth lacks the vast sub-horizontal shelves that existed in previous times. For example, it is possible to trace a remarkable (sic) uniform Paleozoic stratigraphy in marine formations across much of modern North america. Similarly it is possible to trace antoher uniform stratigraphy in shallow marine Mesozoic formaitons across much of Arabia. These are examples of sediments deposited on broad shelves, commonly referred to as 'epeiric seas', the like of which are absent today. This reflects the fact that the earth is now in an unstable and exciting phase of its history, in which the vast continental plates of the past have been rifted and drifted apart."
R.C. Shelly Ancient Sedimentary Environments 4th Ed Chapman & Hall (London) 1996, p197

​

"the ocean bottom is subject to too many disturbances to permit any kind of gradual undisturbed accumulation."
Edwin L. Hamilton: "The Last Geographic Frontier: The Sea Floor," Scientific Monthly, Vol. 85, Dec. 1957, p. 296.

---

On the whole 'epeiric sea' issue I'll agree that I should have simply equated the marine layers on continents with epeiric seas. Maybe it is my problem but it is not clearly explained in the texts whereas, IMO, it should be the bread and butter of such a chapter. All I know is that if I were writing a chapter on 'origin of the geological column' I would state very clearly that most of it is epeiric sea deposits. I would show the sea-level curves. You know I'm still yet to see a geolgoical column diagram which shows, say, 5 local geolgocial columns from around the world and points to which local beds came from which global sea-level rise. Maybe I'll put out a geology text with this sort of clarity in it . I wont claim conspiricy then but I will claim lack of systematic clarity or true interest in where the geological column deterministically came from. The best I've seen is in Hamblin, Christensen and Hamblin. It's the only general geology textbook out of 6 that I've seen that even shows sea-level curves.On storm deposits I've mixed you up with another poster here who claimed that the reason the layers don't look like sea-floor habitats is that the (shallow) sea floor was repeatedly sheared off by storms followed by storm depositions. So ignore what I said in that paragraph please - I'll redirect it to the other guy. BTW - one of the mainstream geolgoy courses on the web raises the issue of whether most marine sedimentaiton in the record is actaully storm deposits for the exact reason I mention. I disagree with them because there are no unconfromities.You might be right about Lyell - it's quite likely that he did talk about the shallow seas. I like the guy. I'll stop using the term 'Lyellian' and start saying 'low-energy non-marine'. Thanks Edge, I am clearing up misconeptions through your comments.

Edge, I thought a lot of the MSH layering was formed by mudslides and ash?In any case what's wrong with my detailed scenario I proposed - that the canyon continued to collapse until it was hard enough, eventually leaving a sharp edged canyon?Fractures. I think the facture issue is easy to understand. A fracture in deep bedrock might easily be expected to generate subsidence above it in soft sediments thus seeding that region for runaway gully formation.

​

[This message has been edited by Tranquility Base, 05-30-2002]

^ I agree with you.