Geology of Placer Deposits in the Carib00 Mining District, British Col,umbia; Implications for Exploration

This report provides details on field activities in placer geology conducted by the Applied Geochemistry and Surficia1 Geology Section of the British Columbia Geological Survey Branch. I n 1989, the provincial government expanded the area open to placer mining substantially, and the need for new exploration techniques in these regions was recognized. Studies of gold-hearing placer deposits were undertaken with the objective of developing a set of geological criteria useful for recognizing placer potential i n undeveloped or poorly explored areas. The results of these studies will he used to develop regionally applicahle exploration models. The complexicy of the geology observed during this field season indicate!; that detailed sedimentological studies are required in order to understand both the distribution of placer deposits in a regional sense a:nd the location and extent of pay streaks at the local level. The Cariboo Mining District was selected for initial !study because of its long history of placer gold production. Since 1860 the district has produced almost 100 000 kilogrms (ahout 2.5 to 3 million ounces) of gold, more than any olher