A diamond preserves a bit of the depth.
snip
...
Geoscientists can get a decent idea of the composition of the earth’s mantle based on what is present in the crust because the rocks in the mantle and crust are connected: tectonics move rocks and minerals up and down between the layers over millions of years. The minerals morph and change as they leave the high pressure and scorching temperatures of the lower mantle, however. Diamonds are the only direct window into this region because they do not morph. They form at least 150 km below the surface, with some originating as deep as 1,000 km. Diamonds’ crystalline structure is made of pure carbon, but they often scoop up tiny bits of their surroundings as they form. Because diamonds are incredibly hard, they can seal in these microscopic “inclusions” under very high pressure—even as the diamond ascends to the crust and is plucked by a miner. “The diamond doesn’t let anything in or out,” says Oded Navon, a geologist who studies diamonds and the deep mantle at the Hebrew University in Jerusalem but was not involved with the identification of davemaoite. “It’s really a perfect closed box.”
...
useful victorian slang
Podsnappery: the willful ignorance of someone who refuses to acknowledge fact that doesn’t align with their personal belief.
06:01 in General Commentary | Permalink | Comments (0)