Abnormal composition of carbon isotopes in underground alkaline waters of Kuzbass

Abstract

The first data on abnormally high δ¹³С values in hydrocarbonates (НСО ₃^-) dissolved in underground waters of coal deposits of Kuzbass (up to +30.9‰) are reported. It is shown that such an unusual isotope composition of waters results from the long, strictly directed interaction in the water–rock–gas–organic material system occurring under the conditions of hindered water exchange. Extensive fractionation of C isotopes is the result of the evolution of the water–rock–gas–coal system after penetration of infiltration waters into the coal deposits and their long interaction with all these components, rather than metamorphism of organic material upon its transformation into coal. With respect to such an approach, the isotope composition of dissolved C may indicate the duration of the evolution in the water–rock–gas–organic material system.