Monday, June 9, 2008
Orthogneiss: Inorganic Carbon
This is orthogneiss. Eoarchean orthogneiss from the Isua greenstone belt in Greenland was presumably formed before (3.8 Ga) all life on planet Earth. By definition, orthogneiss is NOT a sedimentary rock. Orthogneiss is a metamorphic rock which comes from the igneous (volcanic) rock granite. It contains bands of black graphite which is pure carbon. This igneous carbon is the inorganic mantle source of carbon found in hydrocarbons.
"We will consider it quite sufficient to recall that chemists of high standing in the scientific world, such as Berthelot and Mendeljeff, have long ago (1866 and 1877 respectively) suggested very probable forms such as carbides under which carbon could exist in the interior fluid magma, and probable reactions under which hydrocarbon compounds could have been generated." -- Eugene Coste, 1903