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Author | Topic: Did the Flood really happen? | |||||||||||||||||||||||||||||||||||||||||
Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
The deposition age of the Siberian Traps, one of the largest volcanic events in Earth's history, started in the late Paleozoic and ended in the early Mesozoic. The bulk of Paleozoic sediments (Great Flood deposits to you) are stratigraphically below (older than) those volcanics and the bulk of Mesozoic (Great Flood deposits to you) are stratigraphically above (younger than) those volcanics. Thus, the volcanic event must have happened during your Great Flood. I offhand find no reference to that the volcanics were a submarine event. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
Lagging way behind in reading this topic, but I'll chip in a thought.
Just because the Silurian strata is vertical or near vertical at that location does not mean that it is near vertical everywhere. Indeed, if that strata is found over a large area, it must be much more horizontal in general. And the cross section diagram is covering that large area. Perhaps it is some more intense local folding??? A small detail that isn't going to show up in "the big picture"??? What would be nice, would be to have a good geologic map and/or cross section that only covers a few miles of lateral distance from that location. I can't find such online. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
A (not THE) geological column refers to the vertical sequence of rocks at a single location/point of the Earth. In concept, a true A geological column is a 1 dimensional object (AKA a vertical line). In practical reality, a A geological column would be a compilation/generalization of a collection of adjacent true A geological columns. An example of a practical reality A geological column would be the rocks of a drill coring, of which there are many examples upthread (of course that would actually be just the top part of that A geological column, as the core does not go to the center of the Earth). But even in that object of 3 dimensions, there would be some variations from 1 vertical (1 dimensional) line to the other vertical lines of the core. Going down the left side of the core would not be a precise mirroring of going down the right edge. The Earth's geology is the compilation of an infinite number of these A geological columns, those of every point of the Earth, be it continental or oceanic. When a geologist refers to THE geological column, he/she is actually referring to a A geological column of a quite specific location. Or more likely is referring to what is better termed as the geological time scale. So, getting back to the coin stack concept. On stack of coins is one column. Of course, the left edge of the stack is not precisely the same as the right edge of the stack. You are deviating from a 1 dimensional object and are starting to generalize. A second adjacent stack is a second column. If the second stack is right side by side to the first stack, then one might generalize that into being a single column. But then you are getting into even more deviations in the 2nd and 3rd dimensions. Returning to the above quoted:
Wrong. A (not THE) geological column is the rocks underlying a single point on the Earth. There are an infinite number of A geological columns, that underlie every point on the Earth. Now there is a muddled mess of a message. Maybe a mooseage. I don't know if all this hair splitting is of any value to the discussion. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined:
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This topic is plastered with thoughts about "the" geologic(al) column that I don't like.
If a geologist refers to "the" geologic column, he is either referring to "a" specific individual geologic column at a specific location OR he is referring to the geologic time scale, which is independent of any specific location of the Earth. Which one would be apparent from the discussion context. I strongly encourage the going to the Geologic Column topic started by NosyNed back in 2003 (16+ years ago!). Edge did a nice message 3 there. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
First of all, a couple of links for further reading:
https://geology.com/plate-tectonics.shtml
There is 3 types of plate boundaries: 1) Divergent - Essentially synonymous with mid-ocean spreading centers, the notable exception being the east Africa rift valley, which is rather a proto-mid-ocean spreading center. These are areas of tension (aka negative pressure). Not directly relevant to continental deformations. 2) Convergent - Essentially synonymous with subduction zones, mostly at ocean crust/continental crust boundaries, although there are also ocean crust/ocean crust subduction zones. The big example is the Pacific ring of fire. An exception to being subduction zones, is the case of continental plate/continental plate collision, the great example being the north end of the India plate. Another exception would be what I'll call obduction zones - Oceanic crust being thrust up upon continental crust, resulting in continental ophiolite complexes. 3) Transform faults - Such as the San Andreas fault in California and the Alpine fault in New Zealand.
The bulk of those plate boundaries are mid-ocean spreading centers. The ocean/continent boundaries are mostly subduction zones or transform faults. An "off the cuff" summary. I'm sure there could be some quibbles about the details.
The origins of the Appalachians is complex, but a big part of it was that the was a continental/continental collision at one or more points in time, when the Atlantic Ocean basin closed. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined:
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If by "sea bed" you mean oceans that are over the continental shelf or seas that were from a greater sea transgression onto the continents, then I would agree with you. If by "sea bed" you mean oceanic crust and sediments, then there is a big difference - The continents have a general specific gravity ("density") of 2.7 while the oceanic crust is 3.0.
Again, significant density difference. See isostasy. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
Actually, an at least partial reason for the height of the mid-oceanic ridges is that the relatively hot rock at the spreading center is slightly less dense than the cooler rock further from the spreading center. Less dense floats higher. quote: https://en.wikipedia.org/wiki/Mid-ocean_ridge#Morphology Links and much more reading at source page. May want to also look at https://en.wikipedia.org/wiki/Guyot All this is pretty irrelevant to continental deposition and deformation considerations. But someones got to put something interesting into the topic. Moose Edited by Minnemooseus, : Clean up formatting a bit.
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
... quote: ... quote: https://en.wikipedia.org/wiki/Gulf_of_Mexico#Geology quote: https://en.wikipedia.org/wiki/Back-arc_basin Another interesting tidbit (or two) I encountered: quote: https://en.wikipedia.org/wiki/Geology_of_Cuba quote: My "bolding". https://en.wikipedia.org/wiki/Ophiolite Tectonics seem to be pretty damn complicated. I seem to be turning into a geo-LamarkNewAge. Oh Flying Spaghetti Monster, save me! Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined:
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I never ceases to boggle me, about how you people can get into such discussions of details when your data source is a simplified big picture diagram. There is a lot of real world detail that is not captured by those big picture "cartoons".
First of all, one shouldn't assume that deposition, deformation, and erosion are sequential processes operating independent of each other. It's not deposition, then deformation, then erosion. Deformation may well be happening while deposition is ongoing, and there certainly is going to be erosion and redeposition of the eroded material while deformation is ongoing. PaulK's first sentence of the first paragraph really gave me a "there's some weird syntax doing on here" feeling. I repeat it:
Any deformation isn't going to happen to any strata before the strata was laid down. So that sentence would be better stated as:
At the Siccar Point angular unconformity, there was most likely erosion and redeposition while the older Silurian rocks were being folded and tilted. I don't offhand have the petrology down, but the upper Devonian rocks were at least in part derived from the erosion of the Silurian - There are clasts of the Silurian now part of the Devonian rocks. Anyway, the deformed Silurian rocks were later further deformed at the same time the Devonian rocks were. As a side note, a perhaps odd situation in one pre-Cambrian rock unit in northern Minnesota. There is a large unit called the Knife Lake Group (or is it Supergroup?). Anyway, a pretty thick stack of sediments. The lower part of the Knife Lake is intruded by the Saganaga "Granite" (actually a tonalite, IIRC). Anyway, a generally granitic type intrusion. The Knife Lake is contact metamorphosed by the Saganaga and both the Knife Lake and the Saganaga are deformed, with the Saganaga crystal structure showing pronounced stretching. But the kicker of this situation is that distinctive cobbles of the stretched Saganaga are found deposited in the more upper part of the Knife Lake. So, the general sequence would be, deposition of Knife Lake sediments, then intrusion by the Saganaga while deposition of the Knife Lake continued, then deformation of the Knife Lake and the Saganaga while the deposition of the Knife Lake continued, then erosion of the Knife Lake and Saganaga in one area while the deposition of the Knife Lake continued in another area. Nutshell - You have the same intrusion intruding and metamorphising a thick sedimentary unit, and later have that same intrusion supplying sediment to a later part of that thick sedimentary unit. Sedimentation, intrusion, metamorphism, deformation, erosion all happened while deposition was ongoing. Or something like that. I don't have time span information for how long that all took. Critiques of my reasonings certainly welcome. Moose Added by edit - A couple of Saganaga Granite links: https://www.jstor.org/stable/30056034?seq=1#page_scan_tab... Edited by Minnemooseus, : Added by edit.
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
Oh really? Wouldn't this highly hypothetical rebound be the same everywhere? How would you detect this? What is this evidence we could see? Moose Edited by Minnemooseus, : Change subtitle.
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
So, how would your "flood geology" explain a statigraphy of a thick layer of blatently land deposited sediment being found in between two thick layers of marine deposited sediments? The flood, the flood went away, the flood came back? Mainstream geology has no problems with multiple floods (repeated sea transgressions onto the continents). But you have only one flood. Moose
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
Not that anything Juvenissun says makes much if any sense, but...
Weathering - Breaking down the rock via physical and/or chemical means. Physical weathering and/or chemical weathering. Physical weathering turns rock into smaller pieces, chemical weathering causes chemical changes in the rock materials (eg feldspars changed into clay(s), or things going into solution). Erosion is the movement of the materials. You can have weathering without having erosion. Moose Added by edit: Just visited the "Do Nothing Button" for enlightenment, and it said:
Edited by Minnemooseus, : Added by edit.
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Minnemooseus Member Posts: 3834 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: |
Geology degree, you ignorant weasel. Moose Professor, geology, Whatsamatta U Evolution - Changes in the environment, caused by the interactions of the components of the environment. "Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham "The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness." - John Kenneth Galbraith "Yesterday on Fox News, commentator Glenn Beck said that he believes President Obama is a racist. To be fair, every time you watch Glenn Beck, it does get a little easier to hate white people." - Conan O'Brien "Politics is not the art of the possible. It consists in choosing between the disastrous and the unpalatable." - John Kenneth Galbraith It says something about the qualities of our current president that the best argument anyone has made in his defense is that he didn't know what he was talking about. - Paul Krugman (as stolen from Chiroptera's signature) "My fellow Americans, I'm pleased to tell you today that I've signed legislation that will outlaw Russia forever. We begin bombing in five minutes" - Ronald Reagan (1984) "I know a little about a lot of things, and a lot about a few things, but I'm highly ignorant about everything." - Moose
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