Interpretation of Thermal Mesophase in Vanadiferous Bitumens from Upper Proterozoic Lava Flows (Mítov, Czechoslovakia)

Abstract

In Mitov, Czechoslovakia, solid bitumens, quartz, calcite, and chlorite form the inter-pillow fillings of Upper Proterozoic pillow lavas. The bitumens, which are similar to poorly ordered graphite, show a marked mosaic and areal anisotropy typical of thermal mesophase that develops during industrial coking processes. The isotopic compn. of the bitumen carbon (X delta 13C = -30.1.permill.) is within the range typical of org. carbon in the adjacent sedimentary rocks (delta 13C = -24.2 to -35.3.permill.). Mineral inclusions in the bitumen contain an anomalous amt. of V. The origin of bitumen may be sought in the processes of pyrolysis and the thermal effects of submarine basalt extrusion on the org. matter of Proterozoic sediments and stromatolites.