The Relationship between Sedex and Carbonate Hosted Zn-Pb Showings in the Selwyn Basin in Yukon and Mackenzie Mountains, NWT

2006

Keith Dewing, Sarah Gleeson, Glen Hendrickson,

Stratiform shale-hosted Zn-Pb deposits in the east-central Yukon and carbonate hosted Zn-Pb deposits in the Mackenzie Mountains, in the NWT may share a common source of mineralizing fluids. As part of a regional Zn-Pb-Ag exploration initiative, Eagle Plains Resources Limited is re-evaluating the parameters controlling mineralization in this district. In 2005 a limited research partnership was formed between Eagle Plains, the GSC and the University of Alberta to study details of the mineralizing systems, focusing on the genesis of the carbonate hosted Zn-Pb showings. The age, fluid chemistry and tectonic setting of Zn-Pb mineralization of some of the carbonate hosted mineralization suggest a temporal link with the shale hosted Zn-Pb deposits in the Selwyn basin. These fluid systems interacted with the carbonate strata in the platform leaving a record of their passage middle Proterozoic through to Devonian rocks. Uplift and exposure of the resistive carbonate units allow a better look at the mineralizing processes operating in the shale basin at the same time. Similar signatures in the Selwyn basin are obscured by the recessively weathering nature of the rocks An Irish Type model for the carbonate host Zn-Pb deposits is favored over the previous MVT model. The linking of fluid movement in the shale basin and adjacent carbonate platform provides a focus for regional exploration which will be discussed in the presentation.