Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists aboard drilling vessel recover rocks from Earth’s crust far below seafloor

07.04.2005


But Earth’s elusive mantle is a near miss



Scientists affiliated with the Integrated Ocean Drilling Program (IODP) and seeking the elusive "Moho"--the boundary, which geologists refer to as the Mohorovicic discontinuity, between Earth’s brittle outer crust and its hotter, softer mantle--have created the third deepest hole ever drilled into the ocean bottom’s crust.

Scientists had hoped to drill into Earth’s mantle, but found instead that their efforts had missed the mark, they now believe by less than 1,000 feet. The X that marks the spot, they now think, is located a short distance to the side of the drill hole.


From the ocean drilling vessel, JOIDES Resolution, the researchers recovered rocks from more than 4,644 feet (1416 meters) below the sea floor that will provide valuable information about the composition of the Earth. And despite coming up short, "This is one of the best efforts to date," said Rodey Batiza, NSF program director for ocean drilling, "to drill into ocean crust and find mantle. It will provide important clues on how ocean crust forms."

IODP’s initial 10-year, $1.5 billion program is supported by two lead agencies, the U.S. National Science Foundation and Japan’s Ministry of Education, Culture, Sports, Science, and Technology.

Scientists aboard two consecutive oceanographic cruises, known as Legs 304 and 305, drilled into the Atlantis Massif, located at the intersection between the Mid-Atlantic Ridge and the Atlantis fracture zone. The central portion of this region is made up of a shallower sea floor feature than the area around it. That "core," scientists believed, would turn out to be composed of rocks that make up Earth’s lower crust and upper mantle, providing a first-ever opportunity to sample the mantle.

The cored rocks, however, are clearly part of Earth’s crust.

Benoit Ildefonse of the Université Montpellier, a co-chief scientist on the expeditions, said, "Deep coring in the ocean crust is a challenging endeavor, and has been a long-term goal for geoscientists since the late 1950s. Post-cruise research [on samples recovered by the drilling] will expand our knowledge of processes at slow spreading mid-ocean ridges, a key component of the Earth’s dynamics."

Co-chief scientists Ildefonse, Donna Blackman of the Scripps Institution of Oceanography, Barbara John of the University of Wyoming and Yasuhiko Ohara of the Hydrographic and Oceanographic Department of Japan, and IODP scientist Jay Miller of Texas A&M University led the expeditions, which drew scientists from IODP’s 18 member countries.

"The rocks cored," said John, "have compositions that represent some of the deepest crust ever sampled. They’re unique in ocean drilling records, and provide an unprecedented opportunity to learn about formation of Earth’s crust."

More drilling to locate the mantle may take place in the same location; at the end of the expedition, the drill hole was open and in good condition, IODP scientists said, and ready to be drilled deeper.

Miller said scientists have a largely preconceived idea of how the Earth evolved, based on previously acquired geophysical data. "The types of rocks we recovered show that this interpretation is oversimplifying many of the features of the ocean’s crust. Each time we drill a hole, we learn that Earth’s structure is more complex. Our understanding of how the Earth evolved is changing accordingly."

The Integrated Ocean Drilling Program (IODP) is an international marine research drilling program dedicated to advancing scientific understanding of the Earth by monitoring and sampling sub-seafloor environments. Scientists affiliated with IODP are conducting research on its principal themes: the deep biosphere, environmental change, and solid earth cycles.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>