Heat generation in solid fossil fuels as a factor of epigenetic inhomogeneity of geological environment

Abstract

Consequences of heat generation caused by exothermic changes in organic matter in the subsurface have been considered. It has been shown that once existed deposits containing solid organic matter and then self-heated, spontaneously ignited, and burnt under subsurface conditions can be traced by not only thermally altered rocks (including ore mineralization, etc.), but also landforms (positive and negative) and increased levels of both dislocations and geofiltration heterogeneity. Elevated temperatures (sometimes up to 1000–1200°C), causing transformation of both organic and mineral matter, create preconditions for deformation of host rocks: void emptying due to loss of a large mass (more precisely, volume) of matter (mainly organic), explosive activity of generated fluids, and the corrosive nature of some of them. As a result, the bed integrity is disturbed, stockwork fracturing (and permeability) develops, and rocks are subjected to impact of corrosive solutions. The role of solid organic matter in the disintegration of rocks has been analyzed. It has been pointed out that not only high temperatures can cause deformation alteration of rocks, but also dislocating nature of the environment can cause heat generation. In any case, there will be spatial alignment of both thermally altered and dislocated rocks.