Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A deep, dark mystery

30.06.2015

UCSB geologist Jim Boles makes new discoveries about the Newport-Inglewood Fault Zone in the Los Angeles Basin

UC Santa Barbara geologist Jim Boles has found evidence of helium leakage from the Earth's mantle along a 30-mile stretch of the Newport-Inglewood Fault Zone in the Los Angeles Basin. Using samples of casing gas from two dozen oil wells ranging from LA's Westside to Newport Beach in Orange County, Boles discovered that more than one-third of the sites -- some of the deepest ones -- show evidence of high levels of helium-3 (3He).


The Newport-Inglewood fault was responsible for the 4.9 magnitude Inglewood earthquake in 1920 and the 6.4 magnitude Long Beach earthquake in 1933.

Credit: Sonia Fernandez

Considered primordial, 3He is a vestige of the Big Bang. Its only terrestrial source is the mantle. Leakage of 3He suggests that the Newport-Inglewood fault is deeper than scientists previously thought. Boles's findings appear in Geochemistry, Geophysics, Geosystems (G-Cubed), an electronic journal of the American Geophysical Union and the Geochemical Society.

"The results are unexpected for the area, because the LA Basin is different from where most mantle helium anomalies occur," said Boles, professor emeritus in UCSB's Department of Earth Science. "The Newport-Inglewood fault appears to sit on a 30-million-year-old subduction zone, so it is surprising that it maintains a significant pathway through the crust."

When Boles and his co-authors analyzed the 24 gas samples, they found that high levels of 3He inversely correlate with carbon dioxide (CO2), which Boles noted acts as a carrier gas for 3He. An analysis showed that the CO2 was also from the mantle, confirming leakage from deep inside the Earth.

Blueschist found at the bottom of nearby deep wells indicates that the Newport-Inglewood fault is an ancient subduction zone -- where two tectonic plates collide -- even though its location is more than 40 miles west of the current plate boundary of the San Andreas Fault System. Found 20 miles down, blueschist is a metamorphic rock only revealed when regurgitated to the surface via geologic upheaval.

"About 30 million years ago, the Pacific plate was colliding with the North American plate, which created a subduction zone at the Newport-Inglewood fault," Boles explained. "Then somehow that intersection jumped clear over to the present San Andreas Fault, although how this occurred is really not known. This paper shows that the mantle is leaking more at the Newport-Inglewood fault zone than at the San Andreas Fault, which is a new discovery."

The study's findings contradict a scientific hypothesis that supports the existence of a major décollement -- a low-angle thrust fault -- below the surface of the LA Basin. "We show that the Newport-Inglewood fault is not only deep-seated but also directly or indirectly connected with the mantle," Boles said.

"If the décollement existed, it would have to cross the Newport-Inglewood fault zone, which isn't likely," he added. "Our findings indicate that the Newport-Inglewood fault is a lot more important than previously thought, but time will tell what the true importance of all this is."

###

Study co-authors include Grant Garven of Tufts University; Hilario Camacho of Occidental Oil and Gas Corp.; and John Lupton of the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory.

This research was supported by the U.S. Department of Energy's Office of Science and Office of Basic Energy Sciences and by the NOAA Pacific Marine Environmental Laboratory.

Media Contact

Julie Cohen
julie.cohen@ucsb.edu
805-893-7220

 @ucsantabarbara

http://www.ucsb.edu 

Julie Cohen | EurekAlert!

More articles from Earth Sciences:

nachricht A 3-D look at the 2015 El Niño
29.05.2017 | NASA/Goddard Space Flight Center

nachricht 'Tiny clocks' crystallize understanding of meteorite crashes
29.05.2017 | University of Western Ontario

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

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...

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

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

New drug reduces transplant and mortality rates significantly in patients with hepatitis C

29.05.2017 | Statistics

VideoLinks
B2B-VideoLinks
More VideoLinks >>>