Electron microprobe analyses of native silver and associated arsenides from the Great Bear Lake silver deposits, Northwest Territories, Canada

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Changkakoti, A., Morton, R. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1986
• Subjects: General Earth and Planetary Sciences; Northwest Territories; Canada; Great Bear Lake; Echo Bay; Camsell River
• Online Access: http://dx.doi.org/10.1139/e86-142; http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-142

The Great Bear Lake silver deposits in the Northwest Territories of Canada occur within two separate domains, namely the Echo Bay sector and the Camsell River sector. In these deposits, native silver occurs in veins, associated with a wide range of Ni-, Co-, and Fe-arsenides, sulphides, and pitchblende in gangues of quartz, calcite, dolomite, rhodochrosite, and fluorite. The host rocks of the veins are for the most part Aphebian volcano-sedimentary roof pendants within the Great Bear batholithic complex. Native silver, nickeline (niccolite), maucherite, safflorite, rammelsbergite, pararammelsbergite, loellingite, skutterudite, cobaltite, gersdorffite, and arsenopyrite were analyzed on the electron microprobe to determine any local or regional chemical variations. Mercury and antimony were found to occur in significant quantities in the majority of the native-silver samples. The silver samples from the Camsell River sector were found to be generally more enriched in mercury than those of the Echo Bay sector. Nickeline, cobaltite, and gersdorffite were found to be enriched in arsenic in the ores of the Camsell River sector, versus those of the Echo Bay sector. Such variations are probably related to differing magmatic sources for the hydrothermal fluids or even to precursor metallo-organic associations and are not due to different rocks hosting the silver-bearing veins.