Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

India’s smoking gun: Dino-killing eruptions

10.08.2005


New discoveries about the timing and speed of gigantic, 6500-foot (2-km) thick lava flows that poured out of the ground 65 million years ago could shift the blame for killing the dinos.



The Deccan Traps of India are one of Earth’s largest lava flows ever, with the potential of having wreaked havoc with the climate of the Earth - if they erupted and released climate-changing gases quickly enough. French and Indian geologists have now identified a 600-meter (2000-foot) thick portion of the lava that may have piled up in as little as 30,000 years - fast enough to have possibly caused a deadly global climate shift.

"Our working hypothesis is that the majority of the total volume of lava might have been erupted in only a few major events spread over only a small fraction of millennia," said Anne-Lise Chenet of the Laboratoire de Paleomagnetisme, Institut de Physique du Globe de Paris (IPGP).


To test that hypothesis, the researchers have combined already known ages of the traps gathered from radiometric dating with magnetic fields frozen in the rocks. Volcanic rocks record information about the Earth’s magnetic field with magnetic minerals that align with Earth’s field like millions of tiny compasses before the lava cools. When the lava solidifies, the compasses are locked in place.

Lava layers that erupted within two or three centuries of each other will record similar magnetic fields, explains Chenet. Longer than that and the natural changes in Earth’s magnetic field start to show up. The team also incorporated information about the lava’s chemistry, the way it flowed and piled up and the red weathered soils between lava layers to estimate the timing and number of major volcanic pulses.

All that information points to the 600 meters (2000 feet) of lava pouring out in as little as 30,000 years. This is enough to have possibly released a climate-altering amount of sulfur gases, says Chenet. An estimate of just how much gas is still being worked out.

Chenet is scheduled to present the latest results of the team’s work on Wednesday, 10 August, at Earth System Processes 2, a meeting co-convened by the Geological Society of America and Geological Association of Canada this week in Calgary, Alberta, Canada.

Chenet and her colleagues’ new work on the Deccan Traps is just the latest in a series of discoveries which appear to weaken the case implicating the Chicxulub impact as the primary player in the Cretaceous-Tertiary (K-T) mass extinction.

"As originally proposed by Vincent Courtillot in 1986, the volcanism might be a key player in mass extinctions," said Chenet. "Research in India has shown the remnants of the impact - iridium in sediments - sandwiched between lava flows, implying that volcanism started before the impact."

In fact, most mass extinctions over the past 300 million years have coincided with large volcanic events, said Chenet. The general rule is that massive volcanism like the Deccan Traps correlates with all major mass extinctions in Earth’s history, she said.

"In only one case is there evidence for both volcanism and impact," she said. And that is the K-T mass extinction that ended the reign of the dinosaurs. "Our view is that impact added to the stress already generated by an ongoing massive eruption, enhancing significantly the extent of the extinction, which would however have taken place even if the impact had not occurred."

Wiped out in the K-T mass extinction were 80-90% of marine species and about 85% of land species. All land animals larger than 25 kg (55 lbs) were obliterated.

The Deccan Traps are a huge pile of basaltic lava extending over more than 500,000 square kilometers. Its original volume likely exceeded 2 to 3 million cubic kilometers, says Chenet. The entire volcanic episode that created the traps took place over about one million years. The source of the massive lava flows is thought to have been the surfacing of a plume of hot material from deep in the Earth’s mantle.

Ann Cairns | EurekAlert!
Further information:
http://www.geosociety.org

More articles from Earth Sciences:

nachricht NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center

nachricht The melting ice makes the sea around Greenland less saline
16.10.2017 | Aarhus University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>