Author:
Armstrong Richard Lee,Ramaekers Paul
Abstract
The Athabasca Group overlies 1.8 Ga or older basement of the Churchill Province and predates uranium mineralization at 1.3 Ga. Cross-cutting diabase dikes have been dated by Rb–Sr mineral isochrons at 1.31 ± 0.07 Ga at Diabase Peninsula, Cree Lake, and 1.16 ± 0.04 Ga at Lazy Edward Bay, Cree Lake. Initial 87Sr/86Sr ratios for these dikes are 0.7040 ± 0.0005 and 0.7036 ± 0.002, respectively. Clastic sedimentary rocks of the Athabasca Group normally show limited variation in Rb/Sr and variable initial 87Sr/86Sr. Sedimentary rocks in two areas near the northern margin of the Athabasca Basin scatter about isochrons of 2.6 Ga, reflecting Archean provenance of detrital material and lack of Sr isotopic homogenization since deposition. Sediment of the tuffaceous Wolverine Point Formation, near Rumpel Lake, is much more variable in Rb/Sr and enriched in Rb relative to Sr and defines a 1.43 ± 0.03 Ga isochron with a 0.7057 ± 0.0005 initial ratio. This is possibly the age of deposition of the Athabasca Group.
Publisher
Canadian Science Publishing
Subject
General Earth and Planetary Sciences
Cited by
42 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献