LAWS OF THE DISTRIBUTION OF NORMAL AND ISOPRENOID ALKANES IN COALS OF DIFFERENT RANKS.

The problem of the origin of caustobioliths is directly connected with questions of the formation of and the search for deposits of coal, petroleum, and natural gas and is therefore of great theoretical and practical interest. The solution to this problem is impossible without a knowledge of the structure of the components of the caustobioliths, a study of the hydrocarbon components is of particular value: their composition and structure probably depend on the initial material and the pathways of its transformation. Of particular interest for genetic comparisons is the determination in the composition of caustobioliths of inherited (relict) structures. In the reported investigation, the hydrocarbons of the series of normal and isoprenoid alkanes in coals of the gelitolite class of different ranks has been studied. The results of the investigation performed show that the laws of the distribution of the normal and isoprenoid alkanes are determined by the degree of transformation of the organic matter in the metamorphic process. The distribution of n-alkanes in brown coals has the form of a two-humped curve with a marked fall in the concentrations of normal C//1//9-C//2//4 paraffins, while for hard coals maximum concentrations of these paraffins are characteristic. A more uniform distribution of the isoprenoid hydrocarbons than for hard coals is characteristic for brown coals.