The Lithogenic Nature of Some Gold Deposits in Carbonaceous–Terrigenous Sequences

Abstract

Carbonaceous–terrigenous sequences hosting the largest gold deposits in Russia are divided for the first time into two lithochemical (normal potassic and anomalous sodic) rock types. It is shown that the type of terrigenous rock alkalinity is governed by peculiarities of the tectonic evolution of sedimentary-rock basins and stages of lithogenesis. The alkalinity type reflects the character of ore-forming processes. In potassic rocks, primarily disseminated-stringer gold–sulfide deposits are formed as a result of sedimentary-diagenetic processes. In sodic rocks, gold–quartz veins and stringer zones are formed as a result of elisional and catagenetic transformations. All these deposits should be identified as lithogenic objects. Processes of the subsequent zonal metamorphism or tectonomagmatic reactivation complicate the structure of gold deposits (sedimentary-diagenetic sulfide and elisional-catagenetic quartz veins) or create new deposits at the expense of primary lithogenic ore material in other lithostructural environments.