According to a new computer model, liquid methane in contact with a partially hydrogen-terminated diamond surface at extremely high pressures and temperatures spontaneously forms longer hydrocarbons, and hence the material of crude oil could be formed deep in the earth.

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The ice then melts, leaving a space below the surface, which caves in under the stress of vehicles and eventually forms a pothole.

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Because most of the peninsula sits on a limestone shelf, there are no surface rivers, and rainwater quickly seeps underground where it gathers and forms subterranean bodies of water known as cenotes.

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And only 10% of the life forms inhabiting that unknown world are known to those on the surface.

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