Sedimentary Rock Formation

Some landforms are just incapable of being formed underwater. Geologists (and I'm not one) are not dummies: they have actually studied such things as the steepest angle that a pile of sand, like a dune, can form under a desert sky vs. under water. It's maybe 30 degrees in air, and way under ten degrees under water. You can do an experiment like that at home with a jar, some water, and a handful of sand. Particle-size distribution is different in wind-blown and water-carried sediment, too, and is subject to experiment to verify which can cause what.As to fossils, I have read of fossilized dinosaur nests that were buried by dunes - no water involved at the time of burial. My bet would be that, in most such cases, groundwater was responsible for bringing in the minerals to consolidate the sediment and fossilize the eggs. But you can bet that the folks digging the nest out paid very close attention to all the features that point to whether the deposit was wind-deposited or not.This message has been edited by Coragyps, 08-29-2005 10:07 PM

I've seen the proposal that all that 800-degree water from the "fountains of the deep" was saturated with salt, and that as it mixed with cool water on the surface, the salt fell out of solution to form, for example, the Zechstien and Louann Salt - both massive sodium chloride deposits. I see a couple of big, large, and humungeous problems with this:
1) Saturated salt water at 700 F contains, if I recall right from the Halliburton Cementin Manual, about 50% salt by weight. If you mix a sample of that brine with an equal weight of freezing-cold fresh water, the mixture will be at a temperature of 350 F or so, and contain 25% salt. However, water at room temperature will still hold 26% salt by weight. So no salt can drop out in this scenario.
2) Noah might have been a little uncomfortable in 350 degree water.....

High angles of repose seen in buried dune faces, for starters. Try the experiment: see how steep a pyramid of sand you can make in a piepan with everything dry. Repeat with the pyramid completely under water. Compare steepness of the sides.QED means "that which was to be shown:" it's the traditional last line of proofs in geometry or logic. Try the experiment. You'll get a QED.

I haven't been to Mongolia to look, but I'll bet that the sand grains entombing the nest are wind-borne grains: frosted, and with bedding preserved at angles far greater than those possible for sand deposited under water.Have you done the experiment I suggested at the start of this thread yet? Sand, a glass pie pan, and then a pyramid of sand a) under water and b) without water? You could even add a protractor and actually measure the angles you can achieve.

The original report of the nesting oviraptor - Norell, M. A., J. M. Clark, L. M. Chiappe, and D. Dashzeveg, 1995: A Nesting Dinosaur, Nature, 378, 21/28 December, pp. 774-776. - is just old enough that Nature wants $30.00 to read it online. I didn't want to bet that much, but if one of you kind folks is near a real library, I'm sure the paper gives some details.