CompuServe Messages

<< Fossils are unlikely to "wash down" to younger layers because the younger sediments overlay the older ones. Only in an area where a tremendous upheaval has occurred and inverted the stratigraphy (like the rim rocks around Meteor Crater, AZ) or where faulting has aligned the sequence of adjacent rocks out of order would you be able to find older fossils washing down into younger fossil beds. >> I guess I didn't make clear my term "washing down". I was attempting to describe a process in which, for example, fossils from an exposed Pennsylvanian bed would be freed from the matrix by erosion or solution and re-deposited more or less intact along with other sediments into a bed of Permian or later age. I didn't mean "washing down" in the sense of "up" and "down" vertically, but rather in the sense of older material being eroded and "washing down" as sediment which would be incorporated into younger beds. Picture a conglomerate of a given age containing within its pebbly matter transported fossils from the older eroding highlands.