plate tectonics tagged posts

Rice University scientists propose that life in the solar system could have been very different – See more at: http://news.rice.edu/2016/07/05/lush-venus-searing-earth-it-could-have-happened-2/#sthash.pz2Lc0vd.dpuf

Life in the solar system could have been very different. If conditions had been just a little different an eon ago, there might be plentiful life on Venus and none on Earth. The idea isn’t so far-fetched, according to a hypothesis by Rice University scientists who published their thoughts on life-sustaining planets, the planets’ histories and the possibility of finding more...

A specimen of a Witwatersrand diamond. Credit: Wits University

The 3 diamonds extracted from 3B-yr-old Witwatersrand Supergroup – the rock formation that is host to the famous Johannesburg gold mines to study when modern-style plate tectonics began to operate on planet Earth. “Because diamonds are some of the the hardest, most robust material on Earth, they are perfect little time capsules and have the capacity to tell us what processes were occurring extremely early in Earth’s history,” says Dr Katie Smart.

A cluster of the Witwatersrand diamonds. Credit: Wits University

The Earth is ~4...

Venus as a model: Today this planet looks like the Earth might have looked before the onset of plate tectonics. Credit: NASA/JPL

It is common knowledge that Earth’s rigid upper layer called lithosphere is composed of moving plates. But just what mechanism first set plate tectonics into motion still remains a mystery. Scientists have now come up with one possible answer with simulations. But just as in the past, earth scientists still do not understand what triggered plate tectonics in the first place, nor how the first subduction zone was formed. A weak spot in the Earth’s lithosphere was necessary in order for parts of the Earth’s crust to begin their descent into the Earth’s mantle...

A team from US, France, U.K. is reporting data sent back by Mars rover Curiosity suggests Mars may have once had a continental crust similar to Earth. They describe 20 rocks that had been probed by the rover, and why their findings suggest a different history for the planet than has been thought. Researchers believe they have found evidence that suggests that rather than a lack of magmatic planetary activity, which should have been evident in rock samples showing mostly basalt, rock samples are full of silica and have a rich composition.

The light-colored rock samples are from an area inside the Gale Crater (in the southern hemisphere near Mount Sharp) and have been dated back to approximately 3.6B years ago...