* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Meteorite News -> Chesapeake Bay Impact
Post Info TOPIC: Chesapeake Bay Impact
Blobrana


L

Posts: 131433
Date:
RE: Chesapeake Bay Impact
Permalink  
 

Bay crater may extend into Isle of Wight County

The Chesapeake Bay impact crater, an impressive 80-plus miles across, may actually be a little bigger than that. State and federal scientists following up on a water-well permit have determined that the crater disrupted aquifers and left a rocky debris field at least as far south as Carrollton in Isle of Wight County.
Read more



__________________
Blobrana


L

Posts: 131433
Date:
Chesapeake Bay
Permalink  
 

Geologist and palaeontologist Ralph Eshelman said that from roughly 23 million to 5 million years ago, during the Miocene Epoch, this had been what scientists now call the Salisbury Embayment, a bight or cove-hundreds of miles wide-along the edge of an ancient sea. A cape to the south of the modern Chesapeake and a long curved seacoast bowed westward toward the Appalachians, arcing northeastward to a second cape where New Jersey's Pine Barrens lie above sea level today.
The fossil record at Calvert Cliffs indicates that the climate might have been similar to that of the coast of Georgia. It was a feeding and calving ground for many extinct marine mammal species. One can't walk very far along the shoreline beneath today's towering cliffs without finding a fragment of bone from one of these species. Very often, whole skeletons emerge from the cliffs. Palaeontologist Steven Godfrey and colleagues from the Calvert Marine Museum, acting on a tip from an amateur fossil collector, excavated much of an extinct whale, including the skull which, when packaged in protective plaster, was so heavy a Navy helicopter from the Patuxent Naval Air Station was engaged to hoist it for conservation at the museum.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
RE: Chesapeake Bay Impact
Permalink  
 

Scientists drilling into the site where a giant meteorite smashed into the lower Chesapeake Bay millions of years ago have found one more surprise amid the microscopic life and pockets of prehistoric ocean.

The water is saltier than expected - and no one is sure why.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

The true impact of an asteroid or comet crashing near the Chesapeake Bay 35 million years ago has been examined in detail for the first time. The analysis reveals the resilience of life in the aftermath of disaster.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Eocene meteor
Permalink  
 

In 2003, during construction of Interstate 99 in Centre County, Pennsylvania, state road builders hit the mother lode. That's a bad thing.
At a place called Skytop Mountain, 10 miles west of State College, PennDOT engineers encountered a huge deposit of iron pyrite laced through the sandstone ridge. Exposed to air and water, this highly reactive material became an environmental nightmare, leaching sulphuric acid into a nearby stream and groundwater. Subsequent efforts to contain the damage have so far cost more than $79 million.
What caused this massiveand unexpectedsulphide deposit? Barry Scheetz and his colleague Ryan Mathur pin the blame on a meteor that crashed 35 million years ago smack into Chesapeake Bay.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
RE: Chesapeake Bay Impact
Permalink  
 

Core samples some taken from soil more than a mile deep at a site on the Eastern Shore just north of Cape Charles dont appear to answer the big question: What formed the crater? according to at least one of the lead scientists on the international project.  
Credit MORT FRYMAN | THE VIRGINIAN-PILOT FILE PHOTO  

Source

Attachments
__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

The impact crater that lies beneath the Chesapeake Bay is both better known and more mysterious than ever, according to 53 papers and posters to be presented at a geology meeting this week in Denver.
Highlights of the research include the finding of microbes and DNA in the cores, a boon for scientists studying how to look for life on Mars, but still hanging are questions about what that means. Also unresolved is what formed the 53-mile-wide crater, what happened in the first million years after impact, and exactly how deep the planet was fractured.

"I think we made clear progress on all fronts" - Greg Gohn of the U.S. Geological Survey, one of four principal investigators.

The reports present the first results from an international project that cored more than a mile into the Earth to retrieve samples of rocks near the centre of the 35-million-year-old buried crater. The drilling took place in late 2005, on Eyreville farm just north of Cape Charles on the Eastern Shore. Research from the project, funded in part by the International Continental Scientific Drilling Program, a consortium of science agencies in 13 countries, will be presented at the Geological Society of America meeting. Two sessions of the five -day conference will be devoted to the Chesapeake Bay impact crater.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Chesapeake Impact Structure
Permalink  
 

The U.S. Geological Survey has set a date for a meeting where scientists will divide up the results of last fall's drill into the Chesapeake Bay Impact Crater.
The so-called "sampling party" will take place the week of March 19, 2006.
The Chesapeake Bay Impact Crater is the largest of its kind in the U.S. and the seventh-largest in the world.
More than 100 scientists from around the world have been invited to the March event. It will take place at the USGS headquarters in Reston, Virginia, US, where the samples are housed.

Scientists will identify areas of the samples they want to study.

__________________
Blobrana


L

Posts: 131433
Date:
RE: Chesapeake Bay Impact
Permalink  
 

Initial findings from the Chesapeake Bay impact crater show that the drills first penetrated clay, sand and sediments before they reached pulverized stones known as suevite that were melted by the impact. When one drill bit got stuck halfway down, two of them had to be replaced, which meant crews weren't able to reach their initial target depth of 7,200 feet.

The surprise was what stalled the drills between the sediment and stones: a huge slab of granite that starts at 3,600 feet and extends down to about 4,500 feet. How it got there remains a mystery.

"The granite was a complete surprise to everybody. We had never anticipated this 900-foot block of granite, and we're going to have to rethink and reinterpret some pretty big things about the crater structure" - J. Wright Horton, a bay impact crater expert for the U.S. Geological Survey.

The granite is lodged between sedimentary material that washed into the area after impact and a layer of crushed stone that was partially melted by the meteorite. One issue ripe for review is exactly what type of debris filled the hole in the sea floor moments after the meteorite hit.

"It could mean new models of crater formation" - J. Wright Horton.

Experts are unsure if the granite slid into the crater bed from the rim or was pushed there by massive shifting of the earth when the meteorite hit. Scientists also are unsure whether they've actually reached the bottom of the crater. Further study may resolve such questions.

"We don't exactly know what we have right now, even though the drilling phase is over. We still have to go through the scientific phase and analyse all the material" - J. Wright Horton.

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

The drilling is over:

The scientists at the drill site on an Eastern Shore farm took their last core from an ancient impact crater Sunday morning, at about 1766 metres. Drilling into the Chesapeake Bay Impact Crater began in mid-September and ran nearly continuously for almost three months.
After the core was raised in the wind and rain at about 8 a.m., the scientists began lowering numerous probes into the borehole and ran into some minor trouble. The probing should end today and the site will come down.
There was no ceremony to mark the final core.

"We were more glad to be finished than anything. We're packing up what we can now."- Greg Gohn, U.S. Geological Survey researcher directing the project.

The USGS paired with the International Continental Scientific Drilling Program on the nearly $1.5 million project to dig into the basement of the 85 kilometre-wide crater. The crater's epicentre is Cape Charles.
Geologists say a fiery space rock, probably an asteroid, blasted into coastal Virginia more than 35 million years ago, carving a hole that quickly filled with tons of water, rubble and debris.
The Chesapeake Bay Impact Crater is the largest of its kind in the United States and the seventh-largest in the world. It sits 305 metres beneath the lower part of the bay, surrounding peninsulas and the intercontinental shelf of the Atlantic Ocean.
Earlier bore holes were drilled along the crater's outer rim in Mathews County, Newport News and at NASA's Langley Research Centre. The deepest was about 823 metres.
In early March, dozens of scientists will gather for a "sampling party" to retrieve specific sections of the cores, housed by the USGS in Reston, for their research.

Scientists expect the drilling to reveal more about the effects the prehistoric impact had on the region's geology and water supply and to help better estimate the space rock's speed, size and energy as it slammed into the seabed. Other scientists will study samples of prehistoric water found in the cores that had been trapped in the crater's depths by the impact's aftermath.

__________________
1 2  >  Last»  | Page of 2  sorted by
 
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Meteorite News -> Chesapeake Bay Impact


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard