The Ol Doinyo Lengai in Tanzania oozes black goo called carbonitite lava that flows more like water instead of the hotter red stuff of most volcanoes. Now scientists think they know why.
The volcano sits in the Great Rift Valley, which is sinking and will eventually sit on the sea-floor in the distant future. The carbonitite is typical of sea-floor volcanoes, where the planet's crust is thin and material is pulled from the mantle below.
Ol Doinyo Lengai, they think, is behaving already much like a the sea-floor volcano it will become.
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