Source Rocks and Petroleum Geochemistry

Abstract

As discussed in Chap. 1, petroleum is generated from organic matter which accumulates in sedimentary basins. Only a small fraction of the organic matter produced in the photic zone in the ocean becomes trapped in sediments (Fig. 14.1). Most of the organic matter is oxidised in the water column or on the seafloor and the nutrients are released into the water and become available for new organic production near the surface during upwelling. Most source rocks are black shales like the Upper Jurassic Kimmeridge Clay and its equivalents in the North Sea basin (Fig. 14.2).