Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Geologists drill into fossil magma chamber deep under the ocean

24.04.2006


International collaboration brings up first samples of hard rock called gabbro in intact ocean crust



Scientists aboard the research drilling ship JOIDES Resolution have, for the first time, drilled into a fossil magma chamber under intact ocean crust. There, 1.4 kilometers beneath the sea floor, they have recovered samples of gabbro: a hard, black rock that forms when molten magma is trapped beneath Earth’s surface and cools slowly.
The scientists, affiliated with the Integrated Ocean Drilling Program (IODP), published their findings on April 20 in Science Express, the online edition of the journal Science.

Although gabbro has been sampled elsewhere in the oceans where faulting and tectonic movements have brought it closer to the seafloor, this is the first time gabbro has been recovered from intact ocean crust.



The borehole into the magma chamber took nearly five months to drill, and required the use of twenty-five hardened steel and tungsten carbide drill bits. Getting there "is a rare opportunity to calibrate geophysical measurements with direct observations of real rocks," said geophysicist Doug Wilson of the University of California at Santa Barbara, lead author on the Science Express paper. "Finding the right place to drill was probably the key to this success."

Wilson and his IODP colleagues found that place by identifying a region of the Pacific Ocean that formed some 15 million years ago when the East Pacific Rise was spreading at a "superfast" rate of more than 200 millimeters per year, faster than any mid-ocean ridge on Earth today.

"We planned to test the idea that magma chambers should be closest to the Earth’s surface in crust formed at the fastest spreading rate," said Wilson.

"These results confirm ideas about the way in which fast-spreading oceanic crust is built," said Jamie Allan, IODP program director at the U.S. National Science Foundation, which co-funds the program. "This new understanding opens the way to understanding the origin of oceanic crust, which we can best do by deep drilling."

"We’ve accomplished a major goal scientists have pursued for more than 40 years," agreed geologist Damon Teagle of the National Oceanography Centre at the University of Southampton, a co-chief scientist of the drilling expedition. "Our research will ultimately help answer an important question: how is new ocean crust formed?"

The formation of ocean crust is a key process in the cycle of plate tectonics, which constantly repaves the surface of the planet, builds mountains, and leads to earthquakes and volcanoes.

"Sampling a deep fossil magma chamber will allow us to compare its composition to overlying lavas," said expedition co-chief scientist Jeff Alt of the University of Michigan. "It will help explain whether ocean crust, which is about six- to seven- kilometers thick, is formed from one magma chamber or from a series of stacked magma lenses. The size and geometry of these lenses affect the composition and structure of the ocean crust, and circulation of seawater through the crust."

Such circulation leads to the formation of spectacular hydrothermal "black-smoker" vents--oases that support exotic life forms in the deep ocean.

IODP is an international marine research drilling program dedicated to advancing scientific understanding of the Earth, the deep biosphere, climate change, and Earth processes by monitoring and sampling sub-seafloor environments.

IODP is supported by two lead agencies, the U.S. National Science Foundation and Japan’s Ministry of Education, Culture, Sports, Science, and Technology. U.S.-sponsored drilling operations are conducted by the JOI Alliance, comprised of the Joint Oceanographic Institutions, Texas A & M University Research Foundation, and Lamont-Doherty Earth Observatory of Columbia University.

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

More articles from Earth Sciences:

nachricht Impacts of mass coral die-off on Indian Ocean reefs revealed
21.02.2017 | University of Exeter

nachricht How much biomass grows in the savannah?
16.02.2017 | Friedrich-Schiller-Universität Jena

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>