Virginia

Ancient Mystery Revealed

Ancient Mystery Revealed

Considered to be one of the best preserved marine-impact craters on Earth, the massive crater lies 350 to 500 meters below Chesapeake Bay, surrounding peninsulas and the continental shelf of the Atlantic Ocean. Since 1994, it has been officially known as the Chesapeake Bay impact crater. Impact craters may be simple (those with a regular bowl shape) or complex, depending how they were formed. Craters classified as complex, are more than 10 kilometers wide and exhibit additional features. Geologists refer to the Chesapeake Bay impact crater as complex, and explain that it looks like an upside-down sombrero with an upturned outer rim, a trough (long, wide and deep depression in the crater floor having gently sloping slides, wider and shallower than a trench) with a high peak in the center. Since the bolide smashed through nearly a thousand feet of ocean water, a few thousand feet of wet sediment, and 6 miles into the underlying granite basement, the bolide itself was vaporized. The bolide has been estimated by geologists to have been one to two miles in diameter, making the crater that was left at the bottom of the Chesapeake Bay three times larger than any other known crater in the United States. The Chesapeake Bay impact crater measures 50 miles wide, twice the size of the state of Rhode Island and a mile deep, making it as deep as the Grand Canyon.

The Chesapeake Bay impact crater solved a great geological mystery and forced geologists to revise their thinking about the geology of the Atlantic Coastal Plain. However, studies from Poag and Powar’s project, along with ongoing scientific research done by the USGS, reveals how the lasting effects of such an immense blast influenced the area, along with the people who live there. The massive, subsurface crater seems to be the culprit behind several current concerns in the Chesapeake Bay area, such as salty groundwater, rivers’ changing course, sinking land and unusual erosion patterns