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 Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University

nachricht Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>