Sedimentary pyrite as a gold-source in sediment-hosted gold occurrences in the Selwyn basin area, eastern Yukon

Intrabasinal sedimentary pyrite has recently been proposed as a potential gold source for sediment-hosted gold deposits. To evaluate this concept in the Selwyn basin area of eastern Yukon, we use laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to analyse pyrite from the Carlin-type Conrad, and orogenic gold 3Ace occurrences. This paper texturally and chemically characterizes four generations of pyrite in grey to black mudstones and siltstones, but focuses 83% of the analyses on early and late diagenetic pyrite. Diagenetic pyrite from the Conrad occurrence is trace element poor with respect to deposit-proximal pyrite from shales in the Northern Carlin Trend of Nevada, but is similar in composition to distal diagenetic pyrite in these Nevada shales. Diagenetic pyrite from the 3Ace occurrence is very similar in composition to pyrite around the giant Sukhoi Log deposit in eastern Russia. It can be preliminarily concluded that the trace element composition of diagenetic pyrite from the Conrad and 3Ace occurrences is permissive of a locally derived intrabasinal sedimentary pyrite gold source.