Piemontite-bearing Explosion Breccia in Archean Rocks, Labrador, Newfoundland

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Taylor, F. C., Baer, A. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1973
• Subjects: General Earth and Planetary Sciences; Newfoundland; Hopedale
• Online Access: http://dx.doi.org/10.1139/e73-129; http://www.nrcresearchpress.com/doi/pdf/10.1139/e73-129

An explosion breccia, 4 km east of Hopedale, Labrador, occurs in Archean migmatite forming part of the Hopedale Gneiss. The breccia, 105 by 60 m, consists of angular to well-rounded fragments compositionally similar to the country rock. Extensive development of piemontite and epidote is characteristic of the breccia. Two narrow mafic dikes post-date and fill fractures in the breccia. An electron probe analysis of piemontite and epidote shows the former contains 1.86% Mn 2 O 3 and the latter 0.21%. A genesis of the breccia involving fluidization with subsequent development of piemontite by hydrothermal activity is suggested.