GSA Paper Demonstrates Single Impact at Cretaceous-Tertiary BoundaryPaul bristolia at yahoo.com
Mon Apr 2 08:28:10 EDT 2007
There is a new paper on the impact and extinction
at the Cretaceous-Tertiary Boundary. It is:
MacLeod1, K. G., Whitney, D. L., , Huber, B. T.,
and Koeberl, K., 2007, Impact and extinction in
remarkably complete Cretaceous-Tertiary boundary
sections from Demerara Rise, tropical western
North Atlantic. Geological Society of America.
vol. 119, no. 1, pp. 101-115.
They found a single, about 2-cm thick, layer of
spherules, which is interpreted to a primary air-
fall deposit. They found no other spherule layers
in the multiple cores of the K-T boundary section,
which were recovered.
"Sedimentological, geochemical, and paleontological
changes across the boundary closely match patterns
expected for a mass extinction caused by a single
Baton Rouge, LA