Taxonomy term

plate tectonics

Did a geographic shift trigger the Cambrian Explosion?

Roughly 530 million years ago, Earth’s living cast of characters ballooned as a surge of evolutionary development led to the sudden appearance of almost all modern animal groups. Fossils from this period document the change in species, but the geologic, atmospheric and/or biotic factors that may have caused the radiation remain mysterious. Now, a new study suggests that massive changes in the positions of the continents may have played a significant role in sparking the Cambrian Explosion.

27 Mar 2015

Thank subduction for Earth's nitrogen-rich air

Plate tectonics underlies many of Earth’s distinctive features, from its ever-shifting continents to its colliding mountain ranges and continuously forming crust at mid-ocean ridges. According to a new study, the process might also explain another of our planet’s peculiarities: its nitrogen-rich atmosphere.

 
08 Mar 2015

Plate tectonics seen on Europa

Earth is no longer the only body in the solar system where plate tectonics operates, according to new research reported in Nature Geoscience. 

05 Feb 2015

North American terranes not so exotic after all

The cordillera of western North America is a patchwork of various landmasses, or terranes, that assembled through collision and accretion to the Laurentian Shield, leaving a complicated tectonic history for geologists to unravel.

 
30 Jan 2015

Mantle plume alternative explains Australian volcanism

Magma often finds its way to the surface along Earth’s crustal boundaries as tectonic plates crash together, rift apart or grind past each other. Less understood is why volcanoes sometimes emerge far away from plate boundaries. Narrow plumes of buoyant mantle rock rising from hundreds of kilometers deep have long been supposed as the source of intraplate volcanoes, but evidence for plumes is lacking in many areas. Now, in a new study, researchers have reported evidence for an alternative process, known as edge-driven convection, which appears to be driving intraplate volcanism in southeastern Australia.

 
29 Jan 2015

Skinned oceanic plates may be origin of ophiolites

Long recognized as slivers of oceanic crust incongruously emplaced on land, ophiolites are distinctive sequences of basalt, gabbro and peridotite found globally near former and current convergent zones, where oceanic tectonic plates subduct under continents. But scientists don’t have a clear idea why or how ophiolites split from downgoing plates and find their way onto land. Now, a new study suggests part of the answer may relate to weak layers of mantle that allow oceanic crust to be peeled, or “skinned,” from subducting slabs as they descend.
 

10 Jan 2015

Textbook mantle plume theory may need revision

Every basic geology textbook has a section on mantle plumes, which have long been thought to underlie certain island chains and other volcanic hot spots, but hard evidence in support of narrow columns of magma upwelling from deep within the Earth’s mantle remains scant. Now a new study suggests that the long-held plume theory should be abandoned altogether.

07 Jan 2015

South American fossils offer revised view of Gondwana assembly

Fossils of a known age have been found for the first time in rocks in Brazil that, although long-studied, had previously eluded scientists’ attempts to pinpoint their age. The discovery of the marine animals dates the rocks to 550 million years ago, researchers say, offering important insights into the geological evolution and timing of the assembly of the former supercontinent Gondwana.
 

25 Aug 2014

Unlocking the Cascadia Subduction Zone's secrets: Peering into recent research and findings

Megathrust earthquake hazards drive much of the research into the 1,000-kilometer-long Cascadia Subduction Zone, which lurks off the coast of California, Oregon, Washington and British Columbia. New studies are helping elucidate what is happening off the Pacific Northwest coast.

20 Jul 2014

Searching for evidence of ancient subduction

For billions of years, portions of Earth’s rigid surface have dipped and sunk along plate boundaries to be recycled back into the mantle below. Determining when the process of subduction began — a fundamental step in Earth’s physical, and possibly biological, evolution — has proved difficult for geoscientists due to the challenges of interpreting evidence from the few remnants of early Earth that remain. In a recent study, researchers have now proposed a new approach for identifying ancient subduction zones that could help tackle the longstanding question.
 

06 Jul 2014

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