SOME MICROSCOPICAL PHENOMENA RELATED TO PRIMARY MIGRATION.

A key stage in oil evolution is its primary migration i. e. its movement within and out of its source rock. The process involves the organic and inorganic components of the rock and its pore system. Changes in these components are examined by optical and scanning electron microscopy and complemented by porosimetry. The sample series of this study was obtained from an organic rich shale of Upper Cretaceous age from Pujortoq, Nugssuaq Peninsula, West Greenland. It is shown that the 'reactive' organic components are transformed and micrinite grains develop. The newly generated amorphous fluorescing organic phase is unevenly distributed in the pore system and changes its optical properties with the distance from the dyke.