bullethead
Of the hard cast variety
From : https://www.yahoo.com/news/fossils-show-ancient-seafloor-gave-rise-life-123202372.html
"The rocks date to a time when the Earth's mantle, the viscous layer just below the outer crust, was exposed to seawater. Scientists have long suspected that this mix of deep-Earth rocks and ocean water could have created conditions ripe for life. The new study, published today (Aug. 31) in the journal Proceedings of the National Academy of Sciences, reveals how those chemical reactions might have happened."
"The rocks date to a time when the Earth's mantle, the viscous layer just below the outer crust, was exposed to seawater. Scientists have long suspected that this mix of deep-Earth rocks and ocean water could have created conditions ripe for life. The new study, published today (Aug. 31) in the journal Proceedings of the National Academy of Sciences, reveals how those chemical reactions might have happened."
