Geochemical signatures of gold provinces in South Greenland

Abstract

Many gold occurrences have been discovered in South Greenland over the past ten years as a result of exploration by companies and the Geological Survey of Denmark and Greenland. Their location is examined in relation to regional geochemical distribution patterns as recorded by stream-sediment data. All of the zones of known gold mineralization are outlined by gold anomalies in both stream sediments and heavy-mineral concentrates. In the Archaean craton epigenetic, shear zone-related gold mineralization hosted by Archaean greenstone deposits lies within a pronounced high-As-Sc province, which also covers Palaeoproterozoic supracrustals-the host of one gold occurrence. In the Palaeoproterozoic Ketilidian orogen twelve occurrences of epigenetic gold mineralization have been found, of which five are located along the southeastern margin of the so-called Batholith Zone, which is interpreted as the root zone of a volcanic arc, and seven in metasediments interpreted as fore-arc deposits. A high-As province defined by stream-sediment data covers the entire Ketilidian sedimentary basin, and zones of gold mineralization are characterized by regional anomalies for Cs and local anomalies for Sb and Sc.The spatial relationships are used to propose that coinciding anomalies for As, Sb, Au, Cs and Sc be used as a prospectivity criterion for epigenetic gold mineralization in the Ketilidian orogen. The geochemical data are further used in discussion of a multi-stage model for the gold mineralization, according to which a first-stage concentration of gold and pathfinder elements in the Ketilidian sedimentary basin was followed by late-stage remobilization of these elements as a result of late- to post-Ketilidian granite magmatism.