Earth's Primeval Continents (Ancient / Bygone Continental Masses)

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#1
Long-lost continent found submerged deep under Indian Ocean
By Alice Klein

An ancient continent that was once sandwiched between India and Madagascar now lies scattered on the bottom of the Indian Ocean.

The first clues to the continent’s existence came when some parts of the Indian Ocean were found to have stronger gravitational fields than others, indicating thicker crusts. One theory was that chunks of land had sunk and become attached to the ocean crust below.

Mauritius was one place with a powerful gravitational pull. In 2013, Lewis Ashwal at the University of the Witwatersrand in South Africa and his colleagues proposed that the volcanic island was sitting on a piece of old, sunken continent.

Although Mauritius is only 8 million years old, some zircon crystals on the island’s beaches are almost 2 billion years old. Volcanic eruptions may have ejected the zircon from ancient rock below.

Now, Ashwal and his team have found zircon crystals in Mauritius that are up to 3 billion years old. Through detailed analyses they have reconstructed the geological history of the lost continent, which they named Mauritia. ...

https://www.newscientist.com/articl...id=SOC|NSNS|2017-Echobox#link_time=1485906278
 

PeteByrdie

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#2
Long-lost continent found submerged deep under Indian Ocean
By Alice Klein

An ancient continent that was once sandwiched between India and Madagascar now lies scattered on the bottom of the Indian Ocean.

The first clues to the continent’s existence came when some parts of the Indian Ocean were found to have stronger gravitational fields than others, indicating thicker crusts. One theory was that chunks of land had sunk and become attached to the ocean crust below.

Mauritius was one place with a powerful gravitational pull. In 2013, Lewis Ashwal at the University of the Witwatersrand in South Africa and his colleagues proposed that the volcanic island was sitting on a piece of old, sunken continent.

Although Mauritius is only 8 million years old, some zircon crystals on the island’s beaches are almost 2 billion years old. Volcanic eruptions may have ejected the zircon from ancient rock below.

Now, Ashwal and his team have found zircon crystals in Mauritius that are up to 3 billion years old. Through detailed analyses they have reconstructed the geological history of the lost continent, which they named Mauritia. ...

https://www.newscientist.com/article/2119963-long-lost-continent-found-submerged-deep-under-indian-ocean/?utm_medium=Social&utm_campaign=Echobox&utm_source=Twitter&utm_term=Autofeed&cmpid=SOC|NSNS|2017-Echobox#link_time=1485906278
So, Lemuria is back on the table?
 

EnolaGaia

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There's a Lost Continent Hiding Beneath Europe

There's a lost continent hidden below southern Europe. And researchers have created the most detailed reconstruction of it yet.

The lost continent "Greater Adria" emerged about 240 million years ago, after it broke off from Gondwana, a southern supercontinent made up of Africa, Antarctica, South America, Australia and other major landmasses, as Science magazine reported.

Greater Adria was large, extending from what is now the Alps all the way to Iran, but not all of it was above the water. That means it was likely a string of islands or archipelagos, said lead author Douwe van Hinsbergen, the chair in global tectonics and paleogeography in the Department of Earth Sciences at Utrecht University in the Netherlands. It would have been a "good scuba diving region." ...

FULL STORY: https://www.livescience.com/ancient-lost-continent-beneath-europe.html
 

EnolaGaia

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This is interesting, I think. The now sunken continent of Zealandia surrounding New Zealand. ...
Here's more about Zealandia ...

Zealandia , also known as the New Zealand continent or Tasmantis, is an almost entirely submerged mass of continental crust that sank after breaking away from Australia 60–85 million years ago, having separated from Antarctica between 85 and 130 million years ago. It has variously been described as a continental fragment, a microcontinent, a submerged continent, and a continent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995. Zealandia's status as a continent is not universally accepted, but New Zealand geologist Nick Mortimer has commented that "if it wasn't for the ocean" it would have been recognized as such long ago.
FULL ARTICLE: https://en.wikipedia.org/wiki/Zealandia
 

EnolaGaia

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#7
Going even deeper ... New research suggests earth's earliest "continents" (or continent-scale rocky provinces) may survive as masses deep within the mantle.

Underground Continents May Be As Old As Earth

Underground continents deep in Earth's belly may have formed when an ancient ocean of magma solidified on the surface of the baby planet 4.5 billion years ago, according to a new study.

The finding was detailed in a fascinating story on the American Geophysical Union blog GeoSpace.

As reporter Abigail Eisenstadt explains, scientists have known about these buried blobs of hot, compressed rock since the 1970s. Earthquakes reverberate through the rest of the mantle at a steady pace, but hit serious speed bumps when they rumble through these massive hunks of stone. These peculiar patterns of seismic activity helped scientists spot the continents on the border of Earth's mantle and molten outer core, but they still don't know when or how the structures emerged. Some scientists theorize that bits of the planet's crust dipped down into the mantle, broke off and clumped together over time, Geospace reported.

Now, new analyses of volcanic rock paint a different picture: The underground continents may be as old as Earth itself, and likely survived the planet-rocking impact that first formed the Moon, the study authors reported July 31 in the journal Geochemistry, Geophysics, Geosystems.

It’s amazing that these regions have survived most of Earth’s volcanic history relatively untouched, study co-author Curtis Williams, a geologist at the University of California, Davis, told GeoSpace. ...
FULL STORY:
https://www.livescience.com/alcohol-producing-gut-bacteria-harm-liver.html

EARLIER SOURCE @ GEOSPACE BLOG:
https://blogs.agu.org/geospace/2019...ntle-untouched-for-more-than-4-billion-years/
 
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