Abstract: A post-depositional hydrothermal alteration product in White Channel sediments and underlying bedrock is divided into 3 zones. These zones, termed the Bleached Zone, the Iron Zone, and the Footwall Zone, are characterized by the development of secondary clay minerals with moderate to high crystallinities. Trace element concentrations of Fe, Mn, As, Sb, Hg, Co, Ba and S are anomalously high in the Iron and Footwall zones. Three types of low temperature, post-metamorphic veins appear to be spatially related to both the distribution and intensity of alteration. Field relationships of altered and unaltered White Channel sediment show zoning patterns which cannot be explained by surface weathering and percolation of meteoric surface fluids.

Economic implications of the alteration of White Channel alluvium are that there may be a hydrothermal style of gold mineralization, in addition to gold which was initially deposited in a placer environment. Testing and exploration of altered White Channel alluvium should be done with this in mind, particularly for extremely fine-grained gold which may accompany the alteration product.

Authors: Dufresne, M.B., Morison, S.R., and Nesbitt, B.E.

Citation: Dufresne, M.B., Morison, S.R., and Nesbitt, B.E., 1986. Evidence of hydrothermal alteration in White Channel sediments and bedrock of the Klondike area, west-central Yukon. In: Yukon Geology Volume 1, J.A. Morin and D.S. Emond (eds.), Exploration & Geological Services Division, Indian and Northern Affairs Canada, p. 44-49.

Downloads

Name	Comment
Paper	File is .44 MB	Download PDF