Abstract: The Mount Freegold district is an ideal natural laboratory to evaluate the structural and magmatic framework for porphyry, skarn and epithermal mineralization in the Dawson Range. The district is located within a major extensional relay zone of the Big Creek fault system, a regionally significant dextral strike-slip structure in which localized extension facilitated the emplacement of mid to Late Cretaceous magmatic rocks. New mapping defines a previously unrecognized granite pluton at Mount Freegold, as well as the ca. 77 Ma Stoddart pluton, which represents the magmatic roots of hypabyssal intrusive rocks at the Revenue Cu-Mo-Au-Ag deposit and Nucleus Au-Ag-Cu deposit. The relay zone in the Big Creek fault system is partly plugged by the ca. 70 Ma Seymour Creek stock, which is cut by a southern strand of the fault system. Episodic fault movement took place over a minimum 35 m.y. interval during which at least three distinct epochs of magmatic-hydrothermal mineralization occurred.

Authors: Friend, M.A., Allan, M.M. and Hart, C.J.R.

NTS Mapsheet(s): 115I02, 115I06, 115I07

Citation: Friend, M.A., Allan, M.M. and Hart, C.J.R., 2018. New contributions to the bedrock geology of the Mount Freegold district, Dawson Range, Yukon (NTS 115I/2, 6 and 7). In: Yukon Exploration and Geology 2017, K.E. MacFarlane (ed.), Yukon Geological Survey, p. 47-68.

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