December 19, 2008

Magma provides glimpse of past

Geologists say an undisturbed chamber of molten rock in Hawaii is offering new insight into the way continental rock is formed.

The magma, discovered in 2005 when a geothermal power company drilled a mile and a half deep on one of the islands, is the first contact scientists have had with the molten rock from anywhere other than a volcano, The Washington Post reported Thursday.

This is Jurassic Park. This is first contact. Here we see this (continental) stuff being produced in its natural habitat, Bruce D. Marsh, a geologist at Johns Hopkins University, said at a meeting of the American Geophysical Union in San Francisco.

The chamber is the length of a football field and about 50 feet thick.

Continental rock is higher in silica than basalt rock. It is formed from magma as silica-poor compounds crystallize out, leaving silica-rich material that solidifies as it cools, the report said.