Bolide Impact Figure 1. Location of bolide impact and of shoreline when bolide hit. A spectacular geological event took place on the Atlantic margin of North America about 35 million years ago in the late part of the Eocene Epoch. Sea level was unusually high everywhere on Earth, and the ancient shoreline of the Virginia region was somewhere in the vicinity of where Richmond is today fig.
Tropical rain forests covered the slopes of the Appalachians. To the east of a narrow coastal plain, a broad, lime calcium carbonate -covered continental shelf lay beneath the ocean. Suddenly, with an intense flash of light, that tranquil scene was transformed into a hellish cauldron of mass destruction.
From the far reaches of space, a bolide comet or asteroid , kilometers in diameter, swooped through the Earth's atmosphere and blasted an enormous crater into the continental shelf.
The crater is now approximately km southeast of Washington, D. The entire bolide event, from initial impact to the termination of breccia deposition, lasted only a few hours or days. The crater was then buried by additional sedimentary beds, which accumulated during the following 35 million years.
The Chesapeake Bay crater was recently identified by C. Wylie Poag U. Geological Survey, USGS , who has assembled an international team to investigate its characteristics and consequences. Figure 2. Cross section showing main features of Chesapeake Bay impact crater and three coreholes that provided data on these features.
