Diagenesis of Organic Matter in Peat: Rock–Eval Pyrolysis Data

Abstract

Rock–Eval pyrolysis data were obtained on a collection of peat samples at various diagenesis stages (from depths of 0–350 cm) from the Gurskoe deposit, lower Amur area, and on producers of organic matter (OM). The pyrograms of the peat OM are superpositions of three peaks: (1) a low-temperature one, with temperatures of hydrocarbon release lower than 300°C, (2) an intermediate-temperature peak, with hydrocarbons released at 300–400°C, and (3) a high-temperature one, corresponding to hydrocarbon release at temperatures above 400°C. The peaks correspond to the lipid, labile, and kerogen OM components, respectively. The diagenetic transformation of OM is associated with a gradual decrease in the contents of the lipid and labile components and an increase in the content of the kerogen component. The process is the most intense in the upper part of the vertical section.