Impact Damage to Dinocysts from the Late Eocene Chesapeake Bay Event

摘要: Abstract The Chesapeake Bay impact structure, formed by a comet or meteorite that struck the Virginia continental shelf about 35.5 million years ago, is focus of an extensive coring project U.S. Geological Survey and its cooperators. Organic-walled dinocysts recovered from impact-generated deposits in deep core inside 85–90 km-wide crater include welded organic clumps fused, partially melted bubbled unlike any previously observed. Other observed damage to consists breakage, pitting, folding various combinations. entire marine Cretaceous, Paleocene, Eocene section was once present at site has been excavated redeposited under extreme conditions shock, heat, collapse, tsunamis, airfall. preserved reflect these and, as products known impact, may serve guides for recognizing impact-related elsewhere. Features are not unique impacts, such breakage folding, off...