Navigation Links
Ancient magma 'superpiles' may have shaped the continents

COLUMBUS, Ohio -- Two giant plumes of hot rock deep within the earth are linked to the plate motions that shape the continents, researchers have found.

The two superplumes, one beneath Hawaii and the other beneath Africa, have likely existed for at least 200 million years, explained Wendy Panero, assistant professor of earth sciences at Ohio State University.

The giant plumes -- or "superpiles" as Panero calls them -- rise from the bottom of Earth's mantle, just above our planet's core. Each is larger than the continental United States. And each is surrounded by a wall of plates from Earth's crust that have sunk into the mantle.

She and her colleagues reported their findings at the American Geophysical Union meeting in San Francisco.

Computer models have connected the piles to the sunken former plates, but it's currently unclear which one spawned the other, Panero said. Plates sink into the mantle as part of the normal processes that shape the continents. But which came first, the piles or the plates, the researchers simply do not know.

"Do these superpiles organize plate motions, or do plate motions organize the superpiles? I don't know if it's truly a chicken-or-egg kind of question, but the locations of the two piles do seem to be related to where the continents are today, and where the last supercontinent would have been 200 million years ago," she said.

That supercontinent was Pangea, and its breakup eventually led to the seven continents we know today.

Scientists first proposed the existence of the superpiles more than a decade ago. Earthquakes offer an opportunity to study them, since they slow the seismic waves that pass through them. Scientists combine the seismic data with what they know about Earth's interior to create computer models and learn more.

But to date, the seismic images have created a mystery: they suggest that the superpiles have remained in the same locations, unchanged for hundreds of millions of years.

"That's a problem," Panero said. "We know that the rest of the mantle is always moving. So why are the piles still there?"

Hot rock constantly migrates from the base of the mantle up to the crust, she explained. Hot portions of the mantle rise, and cool portions fall. Continental plates emerge, then sink back into the earth.

But the presence of the superpiles and the location of subducted plates suggest that the two superpiles have likely remained fixed to the Earth's core while the rest of the mantle has churned around them for millions of years.

Unlocking this mystery is the goal of the Cooperative Institute for Deep Earth Research (CIDER) collaboration, a group of researchers from across the United States who are attempting to unite many different disciplines in the study of Earth's interior.

Panero provides CIDER her expertise in mineral physics; others specialize in geodynamics, geomagnetism, seismology, and geochemistry. Together, they have assembled a new model that suggests why the two superpiles are so stable, and what they are made of.

As it turns out, just a tiny difference in chemical composition can keep the superpiles in place, they found.

The superpiles contain slightly more iron than the rest of the mantle; their composition likely consists of 11-13 percent iron instead of 10-12 percent. But that small change is enough to make the superpiles denser than their surroundings.

"Material that is more dense is going to sink to the base of the mantle," Panero said. "It would normally spread out at that point, but in this case we have subducting plates that are coming down from above and keeping the piles contained."

CIDER will continue to explore the link between the superpiles and the plates that surround them. The researchers will also work to explain the relationship between the superpiles and other mantle plumes that rise above them, which feed hotspots such as those beneath Hawaii and mid-ocean ridges. Ultimately, they hope to determine whether the superpiles may have contributed to the breakup of Pangea.


Contact: Wendy Panero
Ohio State University

Related biology news :

1. Scientists retrace evolution with first atomic structure of an ancient protein
2. CU-Boulder team discovers first ancient manioc fields in Americas
3. Ancient organisms discovered in Canadian gold mine
4. Amber specimen captures ancient chemical battle
5. Ancient whale fall from Californias Año Nuevo Island one of youngest, most complete known
6. Ancient whale fall from Californias Ao Nuevo Island one of youngest, most complete known
7. 454 Sequencing: Science paper describes a novel, highly efficient method of sequencing ancient DNA
8. Newfound ancient African megadroughts may have driven the evolution of humans and fishes
9. Ancient amphibians left full-body imprints
10. Scientists melt million-year-old ice in search of ancient microbes
11. Ancient fish bones reveal impacts of global warming beneath the sea
Post Your Comments:
Related Image:
Ancient magma 'superpiles' may have shaped the continents
(Date:11/9/2015)... 09, 2015 ... the "Global Law Enforcement Biometrics Market ... --> ) has announced the ... Biometrics Market 2015-2019" report to their ... ( ) has announced the addition ...
(Date:10/29/2015)...   MedNet Solutions , an innovative SaaS-based eClinical ... research, is pleased to announce that it has been ... one of only three finalists for a 2015 ... Growing" category. The Tekne Awards honor Minnesota ... innovation and leadership. iMedNet™ eClinical ...
(Date:10/29/2015)... Oct. 29, 2015  Connected health pioneer, Joseph ... explosion of technology-enabled health and wellness, and the business ... The Internet of Healthy Things . ... smartphones even existed, Dr. Kvedar, vice president, Connected Health, ... care delivery, moving care from the hospital or doctor,s ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... --> --> ... by Transparency Market Research, the global non-invasive prenatal testing ... 17.5% during the period between 2014 and 2022. The ... Analysis, Size, Volume, Share, Growth, Trends and Forecast 2014 ... to reach a valuation of US$2.38 bn by 2022. ...
(Date:11/24/2015)... ... November 24, 2015 , ... In harsh industrial ... points for in-line sensors can represent a weak spot where leaking process media ... of retractable sensor housings , which are designed to tolerate extreme process conditions. ...
(Date:11/24/2015)... LOS ANGELES , Nov. 24, 2015 ... a biotechnology company focused on the discovery, development and ... Marban , Ph.D., Chief Executive Officer, is scheduled to ... December 1, 2015 at 10:50 a.m. EST, at The ... York City . . ...
(Date:11/24/2015)... ... , ... Whitehouse Laboratories is pleased to announce that it has completed construction ... dedicated to basic USP 61, USP 62 and USP 51 testing specific to raw ... and micro testing performed by one supplier. Management has formally announced that ...
Breaking Biology Technology: