Experimentelle und Analytische Planetologie
Das ICDP-USGS Bohrprojekt Chesapeake Bay impact crater, U.S.A.
The about 35 Ma old Chesapeake Bay impact structure has previously been proposed as the possible source crater
of the North American tektites (NAT). New major and trace element data as well as the first Sr-Nd isotope data for
target lithologies, crater fill and post-impact sediments (drill core and outcrop samples) of the Chesapeake Bay
impact structure provide the final proof for this hypothesis. Based on the new isotope data, any relation between the
NA tektites and the Popigai impact crater is excluded, having within 2 s errors
identical ages. In a joint ICDP-USGS
effort, the central uplift of the Chesapeake Bay impact structure will be drilled between June and November 2005
down to at least 2.2 km. Essential new results are expected as Chesapeake had a multi-layered target structure
with about 500 m of water on top of a thick column of water-saturated, soft sediments, and crystalline
bedrocks.
Drittmittelgeber:
Beteiligte Wissenschaftler:
Veröffentlichungen:
|