REGIONAL TO DETAILED GEOCHEMICAL MAPPING OF THE KARIISK ORE DISTRICT,EASTERN TRANS-BAIKAL REGION, RUSSIA

The Kariisk ore district is situated in a dome-ring complex formed dur ing late Mesozoic tectono-magmatic activity. The district comprises ma gmatic to post-magmatic vein-type mineralizations, which developed dur ing four stages characterized by different mineral parageneses: (1) qu artz-pyrite-tourmaline; (2) quartz-actinolite-magnetite; (3) quartz-ar senopyrite; and (4) quartz-carbonate-polymetallic. Geochemical surveys at regional to detailed scales involved ca. 12 000 rock samples which were analyzed for 40 elements including Au and associated elements Bi , W, Ag, B, As, Mo, Cu, Ph, Sn, and Zn. The results are presented as g eochemical maps illustrating the distribution of anomalous gold and mu lti-element associations. The geochemically anomalous area shows a fin ger-like pattern radiating from the core of the ring complex and has a concentric zoning of element associations outwards from the margin of the core: W-Mo, Bi-Ag-B, Au-As-Cu-Pb, and B-Ag-Zn. These features are interpreted to reflect that the mineralising process induced by heat from the granitoid magma in the core of the complex occurred in a numb er of separate pulses.