ANCIENT COAL FIRES AS NEW CLIMATE TRACERS (EXAMPLE FROM THE KUZNETSK COAL BASIN, SW SIBERIA, RUSSIA)

摘要

Natural coal fires and related thermal alteration (combustion metamor-phism) of sediments constitute a separate global-scale geological phenomenon. Numerous coal ignition events occurred in Pliocene-Holocene time (Sokol et al., 2005; Stracher et al., 2010). In situ coal seams cannot burn for the lack of oxygen but combustion becomes possible as coal-bearing sediments reach the surface aeration zone as a result of uplift and ensuing erosion. Once being exposed to aeration, coal absorbs oxygen and either inflames or rapidly looses the ignition ability by oxygen deactivation (Kukharenko, 1960; Stracher et al., 2010). Large coal fires are common to areas of warm climate (Pogrebnov, 1978; Heffern et al., 2007; Stracher et al., 2010). Therefore, large-scale combustion of coal may have been a prompt response to tectonic activity and erosion, mostly during Late Cenozoic warm cycles.