Abstract: Placer gold deposits in the Indian River area, west-central Yukon, are grouped into five classes based on thickness, grain size, composition, age, process, landform and exposure. The placers vary from 1.5-16 m in thickness and consist of slightly muddy, sandy gravel that is dominated by either vein quartz clasts, or igneous and metamorphic clasts. The gravel was deposited on floodplains, now preserved as terraces and creek and river valley fills, that range from Pliocene(?) to Holocene in age. The formation of the placers is related to a hierarchy of physical scales: at the lithofacies scale (ms), bed roughness determined sites of gold deposition; at the element scale (10s of ms), gravel bars were preferentially enriched in gold; at the reach scale (100s of ms), stream gradient was an important factor; at the system scale (100s of kms), braided river environments transported large amounts of gold; and at the sequence scale (1,000s of km 2 ), economic placers formed in the White Channel Gravel unit in downstream parts of the Indian River drainage, and in upstream parts of the drainage in the unit herein referred to as the Local Creek Gravel.

Authors: Lowey, G.W.

Keywords: placer source-mineralization, Surficial Geology

NTS Mapsheet(s): 115N, 115O

Citation: Lowey, G.W., 1999. The geology of placer gold deposits in the Indian River area, west-central Yukon. In: Yukon Exploration and Geology 1998, Roots, C.F. and Emond, D.S (eds.), Exploration and Geological Sciences Division, Yukon Region, Indian and Northern Affairs Canada, p. 117-124.

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