[meteorite-list] Mapping the Demise of the Dinosaurs

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed, 11 Dec 2013 17:04:19 -0800 (PST)
Message-ID: <201312120104.rBC14Jei013675_at_zagami.jpl.nasa.gov>


Mapping the demise of the dinosaurs
Monterey Bay Aquarium Research Institute (MBARI) News Release
December 9, 2013

About 65 million years ago, an asteroid or comet crashed into a shallow
sea near what is now the Yucatan Peninsula of Mexico. The resulting firestorm
and global dust cloud caused the extinction of many land plants and large
animals, including most of the dinosaurs. At this week's meeting of the
American Geophysical Union (AGU) in San Francisco, MBARI researchers will
present evidence that remnants from this devastating impact are exposed
along the Campeche Escarpment - an immense underwater cliff in the southern
Gulf of Mexico.

The ancient meteorite impact created a huge crater, over 160 kilometers
across. Unfortunately for geologists, this crater is almost invisible
today, buried under hundreds of meters of debris and almost a kilometer
of marine sediments. Although fallout from the impact has been found in
rocks around the world, surprisingly little research has been done on
the rocks close to the impact site, in part because they are so deeply
buried. All existing samples of impact deposits close to the crater have
come from deep boreholes drilled on the Yucatan Peninsula.

In March 2013, an international team of researchers led by Charlie Paull
of the Monterey Bay Aquarium Research Institute (MBARI) created the first
detailed map of the Campeche Escarpment. The team used multi-beam sonars
on the research vessel Falkor, operated by the Schmidt Ocean Institute.
The resulting maps have recently been incorporated in Google Maps (maps.google.com)
and Google Earth (earth.google.com) for viewing by researchers and the
general public.

Paull has long suspected that rocks associated with the impact might be
exposed along the Campeche Escarpment, a 600-kilometer-long underwater
cliff just northwest of the Yucatan Peninsula. Nearly 4,000 meters tall,
the Campeche Escarpment is one of the steepest and tallest underwater
features on Earth. It is comparable to one wall of the Grand Canyon -
except that it lies thousands of meters beneath the sea.

As in the walls of the Grand Canyon, sedimentary rock layers exposed on
the face of the Campeche Escarpment provide a sequential record of the
events that have occurred over millions of years. Based on the new maps,
Paull believes that rocks formed before, during, and after the impact
are all exposed along different parts of this underwater cliff.

Just as a geologist can walk the Grand Canyon, mapping layers of rock
and collecting rock samples, Paull hopes to one day perform geologic "fieldwork"
and collect samples along the Campeche Escarpment. Only a couple of decades
ago, the idea of performing large-scale geological surveys thousands of
meters below the ocean surface would have seemed a distant fantasy. Over
the last eight years, however, such mapping has become almost routine
for MBARI geologists using underwater robots.

The newly created maps of the Campeche Escarpment could open a new chapter
in research about one of the largest extinction events in Earth's history.
Already researchers from MBARI and other institutions are using these
maps to plan additional studies in this little-known area. Detailed analysis
of the bathymetric data and eventual fieldwork on the escarpment will
reveal fascinating new clues about what happened during the massive impact
event that ended the age of the dinosaurs - clues that have been hidden
beneath the waves for 65 million years.

In addition to the Schmidt Ocean Institute, Paull's collaborators in this
research included Jaime Urrutia-Fucugauchi from the Universidad Nacional
Aut?noma de Mexico and Mario Rebolledo- Vieyra of the Centro de Investigaci?n
Cient?fica de Yucatan. Paull also worked closely with MBARI researchers,
including geophysicist and software engineer Dave Caress, an expert on
processing of multibeam sonar data, and geologist Roberto Gwiazda, who
served as project manager and will be describing this research at the
AGU meeting.

For additional information, video, or images relating to this news release,
please contact:

Kim Fulton-Bennett
831-775-1835, kfb at mbari.org

Note: From December 9 to 13, 2013, Kim Fulton-Bennett can be reached in
the AGU pressroom at 415-348-4404

AGU presentation information:
Poster number P41F-1985. Thursday, December 12, 2013, 8:00 AM - 12:20
PM. Hall A-C (Moscone South)
Multibeam mapping of the Cretaceous-Paleogene meteorite impact deposits
on the the Campeche Escarpment, Yucatan, Mexico.
Roberto Gwiazda (presenter); Charles K. Paull; David W. Caress; Mario
Rebolledo-Vieyra; Jaime U. Fucugauchi; Iza Canales; Esther J. Sumner;
Xavier Tubau Carbonell; Eve M. Lundsten; Krystle Anderson
Received on Wed 11 Dec 2013 08:04:19 PM PST

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