The Micropalaeontological Society

Chesapeake Bay Impact Crater Workshop

Reston, Virginia, U.S.A. 21st.-23rd. September 2003

In late September, and immediately after the landfall of Hurricane Isobel, the U.S. Geological Survey hosted an ICDP (International Continental Drilling Program) workshop at Reston, Virginia to define the scientific criteria which will decide the location for a deep well to be drilled in the centre of the Chesapeake Bay Impact Crater (CBIC).

The CBIC impact occurred approximately 35 million years ago (Late Eocene) when a meteorite or comet came to earth on the U.S. Atlantic continental shelf at a location that is currently occupied by the southern part of the Chesapeake Bay and neighbouring land, within the Virginia Coastal Plain. The crater as currently defined is approximately 84 km (53 miles) circular structure. This lies under several hundred feet of younger Tertiary marine sediments.

The structure of the crater has a direct and important effect on the groundwater circulation in the State of Virginia, so any research undertaken will have a strongly economic interest, as well as having an academic side.

The workshop was attended by workers from a wide range of geological disciplines who have been working with impact structures. Notable amongst these, for nannofossils workers, was Jean Self-Trail who presented a poster on the nannofossils biostratigraphy of the CBIC, together with a description of her innovative work on shock fracturing in nannofossils. I was invited to attend by virtue of my current research work on the nannofossils of Silverpit Crater, British Sector, North Sea.

It was notable, and gratifying, that in both the main meetings and break out groups, biostratigraphy (which in this case is dominated by nannofossils studies), was seen as an integral and essential component of both the well drilling program and the post-drilling research.

It’s planned to spud the well during 2005, and the drilling platform will be sited near Cape Charles, at the south east end of Chesapeake Bay. It is presently planned that both Jean Self Trail and I will take duties as wellsite geologist/nannopalaeontologist during the drilling of the well.

Dave Jutson