Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

FSU geologist explores minerals below Earth's surface

13.10.2016

New understanding of feldspar elasticity may explain seismic discontinuity

A Florida State University geology researcher is going deep below the Earth's surface to understand how some of the most abundant minerals that comprise the Earth's crust change under pressure.


Assistant Professor Mainak Mookherjee found that the mineral feldspar became softer under extreme pressure.

Credit: Mainak Mookherjee

In a paper published today in Scientific Reports, Assistant Professor of Geology Mainak Mookherjee explores how feldspar, one of the most important minerals in the Earth's crust, changes under pressure. Typically, materials become stiffer when pressure is applied, but Mookherjee found that these pale-colored crystals actually become softer under extreme pressures.

"I am interested in exploring these materials at extreme conditions," Mookherjee said. "Feldspar is very abundant in the earth's crust so we need to understand its elastic property."

Mookherjee's work shows that at a depth of about 30 kilometers from the Earth's surface, feldspar decomposes to denser mineral phases such as pyroxene and quartz. The densification of feldspar could partially explain a scientific observation called seismic discontinuity across the Earth's crust and mantle.

This seismic discontinuity, also called Mohorovicic discontinuity, is the boundary between the Earth's crust and mantle. It was first observed in 1909 by a Croatian scientist Andrija Mohorovicic who realized that seismograms from shallow-focus earthquakes had two sets of waves -- one that followed a direct path near the Earth's surface, i.e., crust, and the other arriving faster and probably refracted from the underlying higher-velocity medium mantle.

"This is the first study of the elastic properties of feldspar at high pressure," Mookherjee said. "And it provides very new insight and a novel way of accounting for the sharp Mohorovicic discontinuity."

Scientists have been working since the late 1950s to understand the Mohorovicic discontinuity that separates the Earth's outermost layer -- oceanic and continental crust -- with the underlying mantle. Last year, researchers from the drill ship JOIDES Resolution made attempts to drill a bore hole across the discontinuity, but fell short. Further drilling attempts are planned for future.

"We care about the mineral structures in the deep Earth and how they transform to denser crystal structures within the Earth," Mookherjee said. "Through a thorough understanding of the atomic scale structures at extreme conditions and how they influence the properties of the Earth materials, it is possible to gain valuable insight into deep Earth dynamics."

###

Mookherjee did his work through computer simulations at the FSU Research Computing Center and facilities at Argonne National Laboratory. The research was funded by the National Science Foundation.

Other researchers contributing to the article are Dhenu Patel, a Tallahassee high school student who interned in Mookherjee's lab last summer; Olle Heinonen from Argonne National Laboratory; Anant Hariharan from Cornell University; Ketan Maheshwari from University of Pittsburgh; and David Mainprice from Université de Montpellier.

Media Contact

Kathleen Haughney
khaughney@fsu.edu
850-644-1489

 @floridastate

http://www.fsu.edu 

Kathleen Haughney | EurekAlert!

More articles from Earth Sciences:

nachricht Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute

nachricht Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>