More than a mile-long core retrieved from Crater Drilling

Jan 12, 2006

Following three months of around-the-clock work, the Chesapeake Bay Impact Crater Deep Drilling Project successfully completed its operations, extracting more than a mile-long segment of rocks and sediments from the Earth. On Dec. 4, the drill bit reached a final depth of 5,795 ft (1.1 miles, 1.77 kilometers) within the structure of the crater.

The impact crater was formed about 35 million years ago when a rock from space struck the Earth at hypersonic speed. Scientists have only recently begun to explore the consequences from that distant event and learn how it has greatly affected the population living in southeastern Virginia today.

"The drilling project was a major success," said Greg Gohn, a U. S. Geological Survey (USGS) scientist in Reston, Va. "We recovered a nearly complete set of core samples from the top of the crater fill to the crater floor." USGS and the International Continental Scientific Drilling Program (ICDP) are the project's sponsors.

Gohn is a co-principal investigator of the drilling project, along with Christian Koeberl of the University of Vienna in Austria, Kenneth Miller of Rutgers University in New Brunswick, NJ, and Uwe Reimold, at Humboldt University in Berlin, Germany.

"This is one of the most complete cores ever obtained in an impact structure," said Koeberl, "and will allow us to understand a shallow-marine impact event at an unprecedented level."

The team successfully recovered the complete succession of post-impact sediments above the crater, the entire sequence of rocks broken up during the impact, and rocks from the crater floor. These samples will allow the project's international science teams to research the post-impact environment, impact-related processes, and the impact process itself. In addition, the team completed geophysical down-hole logging to collect additional data, such as the temperature gradient within the corehole.

Important in this multidisciplinary venture is the analysis of the groundwater reservoir in the Chesapeake Bay impact crater. Findings have direct implications for the millions of people living in the area along Virginia's eastern shore and to future development. Several teams from the U.S. and Europe are investigating the microbial life present in the impact crater, part of intriguing recent studies of life in exotic environments.

"The post-impact sediments record the recovery of the continental-shelf target area from devastating impact mega-tsunamis to the passive continental shelf and coastal plain that continues today," said Ken Miller, who chairs the Department of Geological Sciences at Rutgers University. "Comparison of the section in Virginia with more complete sections sampled in New Jersey and Delaware will yield new insight into global sea-level changes and the distribution of water-bearing units in the coastal plain."

The drillsite is located on private land in Northampton County on Virginia's Eastern Shore. The site was chosen because of its location above the central part of the buried crater. Drillsite activities began with extensive site preparations in July 2005. The drill rig arrived in early September, and scientists recovered the first core sample on September 15th.

Cores are being stored at the USGS in Reston, VA and will be photographed and documented during the next 3 months. In March 2006 members from all international teams will gather at the USGS to obtain samples of the core for their various studies.

Source: United States Geological Survey

Explore further: Similarities between aurorae on Mars and Earth

Related Stories

World's largest asteroid impact site could be in Australia

Apr 07, 2015

Not long ago, asteroid impacts weren't considered as a significant factor in the evolution of Earth. Following the Late Heavy Bombardment, which pummelled the inner solar system around 3.8 billion to 3.9 billion ye ...

Comet lander ends up in cliff shadow (Update)

Nov 13, 2014

A shadow was cast—literally—across Europe's historic mission to land on and explore a comet. Scientists said Thursday the landing craft not only bounced twice, it also came to rest next to a cliff that's ...

Curiosity Mars rover finds mineral match

Nov 05, 2014

(Phys.org) —Reddish rock powder from the first hole drilled into a Martian mountain by NASA's Curiosity rover has yielded the mission's first confirmation of a mineral mapped from orbit.

Recommended for you

Image: Europa's Jupiter-facing hemisphere

7 hours ago

This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter's moon Europa that faces the giant planet. It was obtained on Nov. 25, 1999 by the camera onboard the Galileo ...

A bubbly cosmic celebration

7 hours ago

In the brightest region of the nebula RCW 34, gas is heated and expands through the surrounding cooler gas. Once the heated hydrogen reaches the borders of the gas cloud, it bursts outwards into the vacuum ...

Image: XMM-Newton self-portraits with planet Earth

8 hours ago

This series of images was taken 15 years ago, a couple of months after the launch of ESA's XMM-Newton space observatory. These unique views, showing parts of the spacecraft main body and solar wings, feature ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.