Publication Summary
Issue ID: P2015-01-05
Title: U-Pb geochronology of the Hazelton Group in the McTagg anticliinorium, Iskut River area, northwestern British Columbia
Author(s): Cutts, J.A., McNicoll, V.J., Zagorevski, A., Anderson, R.G., Martin, K.
Series Name: Paper
Publication Year: 2015
Larger Work Citation: in Geological Fieldwork 2014, B.C. Ministry of Energy and Mines, Paper 2015-01
NTS Map Sheet(s): 104B
Place Keyword(s): British Columbia, Eskay Rift, Bruce Glacier, Treaty Ridge, Iskut
Lat/Long (NSWE): 57, 56, -130, -128
Theme Keyword(s): geochronology, Hazelton Group, Betty Creek Formation, Iskut River Formation, Salmon River Formation
Early to Middle Jurassic rocks of the Hazelton Group are extensively mineralized, including the precious metal-rich Eskay Creek deposit that is hosted by bimodal volcanic successions in the Eskay rift. In this study, we present U-Pb zircon ages of seven Hazelton Group volcanic, epiclastic and hypabyssal rocks to establish the absolute ages of Hazelton Group units in the McTagg anticlinorium, east of the Eskay Creek deposit. A felsic volcaniclastic sample from the Brucejack Lake member (Betty Creek Formation) yielded a 187.11.9 Ma U-Pb crystallization age that is consistent with previous fossil and U-Pb age determinations. Six samples from the Bruce Glacier member (Iskut River/Salmon River Formation) yielded U-Pb crystallization ages of 178.51.8, 174.61.8, 174.41.7, 174.71.8, 173.61.7, and 173.31.8 Ma. These ages indicate that volcanic rocks coeval with the Eskay member occur in the McTagg anticlinorium, as far south as Mt. Dilworth.