Abstract: The carbon in sedimentary basins may be derived from:(1)marine carbonates;(2) organic carbon;(3)abiogenetic carbon from thermal degradation;(4)carbon from meteoric calcite,and (5)inorganic carbon in the thermal brine systems.The carbon both in the hydrothermal gold deposits and hydrothermally exhalative-sedimentary deposits has a deep-seated origin.The processes of deep-seated inorganic carbon-bearing hydrothermal fluids spouting onto the sea floor may be interpreted to be the leading factors for the formation of anoxic environments and ore-bearing black shales at the bottom of extensional basins.