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Post by 1dave on Aug 26, 2018 11:09:34 GMT -5
Ryan Anderson Is preparing to study the geology of Mars. One part was visiting the Painted Desert and Petrified Forest. Here is some of his report. blogs.agu.org/martianchronicles/2009/03/22/the-painted-desert-and-petrified-forest/ The colorful layers of the painted desert formed in the triassic period when meandering tropical rivers deposted layers of mud and clay. Some of these layers are due to volcanic ash choking up the rivers and altering to clay. Matt Brown, a fossil preparer at Petrified Forest national park chips away at the protective plaster around the skull of an alligator-like dinosaur. A reconstruction of what one of the dinosaurs being studied at the park may have looked like, based on its skull. More at website.EDIT: Clay-bearing river or delta deposits. These may have been deposited extremely rapidly, since there was the fossil of an 8-foot-tall horsetail in the outcrop, still standing upright and crossing several layers! Annual layers ~ 2 foot thick like varves?
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