The origin and hydrothermal mobilization of carbonaceous matter associated with Paleoproterozoic orogenic-type gold deposits of West Africa
2015
Abstract
Two types of carbonaceous matter (CM) are present at all studied deposits: metamorphosed and hydrothermal. Hydrothermal CM is commonly associated with gold mineralization.
It forms veinlets in hydrothermally altered rocks and quartz veins, or irregular accumulations parallel or subparallel to C-type cleavage within shear zones. The isotopic composition of carbon in metamorphosed as well as hydrothermal CM (-26.2 to -33.1>; PDB) indicates their biogenic origin.
Optical properties, XRD and Raman spectra of metamorphosed and hydrothermal CM within a single deposit are similar.