The effect of increased concentration of organic matter on the rock properties

Rocks enriched with organic matter (OM) are considered: Baltic combustible shale-kukersites and domanic deposits of the Volga-Ural basin, in which organic matter is one of the rock-forming components. The discrepancy between the volume and weight ratios of organic and mineral matter of rocks is noted. The volume significance of the OM of these rocks in the thickness of shale formations and domanic sediments is shown. The high content of OM determines the reduced strength of such rocks. The variability of OM concentrations and other irregularities of shale formations and Domanic rocks (texture, nodule bodies, etc.) are factors of mosaic distribution of areas with different density-strength properties and, as a result, non-uniform reduction of layers and their deformation in case of loss (full or partial) of organic matter.