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A critique of AiG's Geologic Evidences for the Genesis Flood article by an actual geologist.
The reason why we see strata containing marine fossils in areas far from the sea is because the earth's crust is constantly in motion due to plate tectonics. This motion drags overlying rocks along with it as it goes. The places where you see the most movement are along mid-ocean ridges which push rocks outward:
This movement is measurable, an undisputed fact.
As these rocks move closer to the shoreline they collect sediment on top of them from turbidic and other clastic flows. Within this sediment are the remains of oceanic organisms of the sort you find fossilized on top of continents. This sediment is then pushed up on top of the continent in the region of the forearc basin. This is, to my knowledge, the primary mechanism for depositing marine sediments on top of a continent. In the case of AiG's examples, the Grand Canyon and the Himilayas, both experienced major uplift which the created huge disparagement we see in their altitude and sea level.
AiG's hypothesis, that these layers were deposited during the great Flood of Genesis, should seem very inadequate to anyone with the smallest amount of geologic training.
Firstly, if you mix up a bunch of sediment (as happens in a flood) you're going to see a great deal of sorting. The larger, heavier sediment will be the first to fall out of solution while the finer, mud particles will be the very last to be deposited. You can test that out at home by taking a whole bunch of sand and rocks and mixing it up in a big tub. This is absolutely not what we see in the Grand Canyon where we see intermittant layers of mudstone (very fine), sandstone (coarse), limestone (a chemical sediment), and even basaltic lava (I would love to hear how AiG explains that). This geology, on this scale, absolutely cannot be explained by a single flood event.
Secondly, deposited sediment needs to come from somewhere. There is a heck of a lot of sediment in these regions, and if they're going to say they're all deposited in a single event I would love to hear where they theorize the sediment would have come from. They suggest it would have come from somewhere to the Northeast, but I'm not aware of any great sandy deserts in the American mid-west or anywhere in eastern Canada. The only other answer I can think of is this sediment was pushed up from the deep sea by the "fountains of the great deep". This is a poor explanation, since you don't actually find much sediment on the ocean bottom very far from shore.
Sand simply isn't small enough to remain suspended for long enough to reach this far from land, and so in the deep sea you primarily see the deposition of muds or chemicals sediments. Therefore, this explanation would require that God created the earth with a large amount sand covering the deep sea. God would had to have done this knowing full well not only that such a covering would not come about naturally but also knowing that this sandy covering would not last very long since the expansion of the sea floor by the mid ocean ridges would eventually clear it all to the shores of the continents.
I can't speak to their example of the Redwall but catastrophic occurances are a common phenomenon on the planet, especially when we look at a geologic scale (billions of years). These events, such as floods or large ash falls, are going to create a large concentration of fossilized material. The mere existance of such fossil beds around the world is consistent with a global flood, just as it is consistent with countless separate events occuring over the span of 3.9 billion years.
One thing that should be mentioned here, however, is how inconsistent the contents of these many fossil beds is with a single, global flood. Using AiG's example of the Redwall in the Grand Canyon, why are the remains here limited to oceanic organisms (specifically nautiloids)? Aren't they claiming that these were deposited on land? Why are there no land or modern marine organisms found in this strata if everything is being jumbled up by the flood? Why was such a huge concentration of nautiloids dragged so far inland?
I can't find any information to corroborate these claims, so if anyone can provide me with additional information I'd appreciate it. I can picture something such as the Redwall being deposited along the length of the American west coast, but I cannot find information on this specific formation being located on other coasts. The same is true of the English chalk beds.
A formation is only going to be deposited along an area in which the source of the deposition, the rate of deposition, and the depositional environment are all relatively similar. AiG's claim that all of these were so consistent across the entire planet for the duration of the flood seems unlikely.
The existance of sediments in places where there is no nearby source is evidence of nothing more than sediment transport. It's what fluid does, it transports sediment.... however, AiG may be confused as to what fluid is responsible for the Coconino which wikipedia claims to be eolian (wind deposited) and cites McKee, E.D., 1979.
I cannot find a source for AiG's second claim regarding current directions being consistent for 300 million years across the Americas. It would be nice if they sourced this stuff. I suppose they are, therefore, claiming that the "fountains of the great deep" were located some place northeast of the Americas.
'Rapid or no erosion' is an odd phrase, it's like saying you found evidence of 'rapid or no eating' on a sandwich. I assume that 'rapid' is a poorly chosen word and that they meant 'short-lived' or something along those lines.
It's easy to find examples of rock units which show little or no erosion between them, just like it's easy to find rock units with huge amounts of erosion, representing tens of millions of years or more, separating them. I've seen them myself, in person, countless times. The existence of uninterrupted sequences of strata is evidence of constant deposition and does not tell us how fast it was or if it was across the entire planet.
This is a picture from the Grand Canyon:
Look very carefully at this picture as I talk you through it. The main thing you see is a bunch of sedimentary layers of different colors all kind of tilted as you look at them on the canyon wall. Now look at the very top of the canyon wall, you see that big white layer? You see the bottom of that white layer, how it truncates all of the tilted layers at an angle? This is called an angular unconformity and this is exactly the sort of thing AiG is saying we don't see in the Grand Canyon.
Now, what does this represent? Let me explain it. Historically speaking, the first thing that happened is all of those tilted layers were deposited, and when they were deposited they were laid down horizontally. That's how sediment accumulates, in horizontal layers. Eventually they lithified and became what's known as a structural block. This giant block of sedimentary rock was then tilted as a unit until it was approximately in the orientation we now see it.
After this happened time passed, and as time passed erosion took its toll on the rocks. Look at where all of those sedimentary layers get truncated by the white, you see how that top is relatively horizontal? It's horizontal because erosion was wearing down on those rocks, filing them down slowly over time. Eventually the environment changed to a depositional one, and that upper white layer was laid down. That is why we see the white layer intersecting the tilted layers, because lots of time and lots of activity separate the deposition of the tilted layers and the deposition of the white layer.
Rocks can fold even when cold and lithified in the upper crust, provided the pressures on them act on a long enough time scale to create ductile movement. All matter is fluid to some degree, you just have to exert force on it at the right temporal scale to get it to bend rather than break... it's like silly puddy, if you strike it you'll see it break but if you twist it more slowly you'll see it bend.
Rocks can also be made more ductile, and therefore more likely to bend than break when subjected to force, if buried deeply. This places them under more drastic levels of heat which make the rock more malleable - this is often seen in a subduction zone where rocks being pushed towards the continent are often dragged deep before breaking off onto the continent.
As to the specific instance AiG mentions I can't say much because, as is often the case with creationist groups, they mention pieces of evidence without showing them. I would need to see the fold in question as well as the rocks above and below it before I could even begin to explain it.
