Comparative Organic Geochemistry of Some European Oil Shales

Abstract

The distribution, and geology, of oil shales occurring in Western Europe was described in a substantial paper by Bitterli and briefly in a later paper by Schlatter. The interest of the former author was principally the location, depositional environments, mineralogy and organic carbon content of a very large number of bituminous sediments, and he proposed a classification which divided the bituminous rocks into seven categories. Although, in this work, the authors have followed Bitterli to some extent in the locations from which our samples were collected have, for convenience, considered Duncan's classification of three main oil shale lithologies. Although there were two major periods of European oil shale formation, namely deposits of Permo-Carboniferous age which are associated, in part, with coal sequences, and Jurassic deposits often of marine origin, the work undertaken in this laboratory has covered eighty samples from twenty deposits ranging in age from Cambrian to Oligocene. These may be divided, using Duncan's classification into a) those believed to have been deposited in shallow marine basins (Cambrian, Sweden; Permian, England; Lower, middle and upper Jurassic, Scotland/England; Oligocene, France), b) those deposited in large Lacustrine basins (Devonian, Scotland; Carboniferous, Scotland; Permian, France), and c) those deposited in small lagoonalmore » basins, often associated with coal swamp environments (Carboniferous, Scotland; middle Jurassic, Scotland; Tertiary, Germany).« less