Privileged Planet: water helped make continents (Introduction)

by David Turell , Wednesday, July 27, 2022, 16:56 (851 days ago) @ David Turell

A new analysis:

https://phys.org/news/2022-07-earth-ancient-key-continents.html

"Although we understand the modern deep-water cycle, we know very little about how it worked when Earth was still a very young planet," Dr. Hartnady said.

"Multiple lines of geological evidence show that water was transported to great depths within Earth all the way back to 3.5 billion years ago, although it is not well understood how exactly it got there."

Researchers used sophisticated modeling to show that primitive high-magnesium volcanic rocks—that erupted onto the ocean floor in the early Earth—would have soaked up much more seawater than more modern lavas.

"This water, which is locked into particular crystals within the rock, would have been released as the rocks were buried and began to 'sweat.' In modern lavas, this sweating happens at a temperature of about 500 degrees Celsius," Dr. Hartnady said.

"Our findings indicate that much of the seawater initially bound within the ancient primitive lavas would have been released at much higher temperatures, greater than 700 degrees Celsius.

"Importantly, this means that the water was transported much deeper into the early Earth than previously thought. Its release would have caused surrounding rocks to melt, ultimately to form the continents." (my bold)

"Dr. Hartnady said this research helped to explain the inner workings of the planet from more than 2.5 billion years ago."

Comment: more information showing how the Earth evolved. Water with its amazing properties was a key to geologic processes as well as vital to life.