ISSN:
1432-1866
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract The Upper Aillik Group is an Early Proterozoic supracrustal sequence of felsic volcanic and associated sedimentary rocks occurring in the Makkovik Province of Labrador. The unit extends from the coast inland for over 90 km and is host to numerous occurrences of metallic mineralization ranging from indications to deposits. Coastal exposures of the Upper Aillik Group are cut by numerous high level, post-tectonic cupolas, whereas, inland the cupolas are lacking. There are three types of mineralization in coastal portions of the Upper Aillik Group, viz.; lead-zinc, molybdenite and uranium. Pb isotope data indicate the age of the post-tectonic granites. Skarnoid and disseminated molybdenite mineralization associated with these same granites indicate the molybdenum was probably derived from the granites. Similarities in REE patterns for the U, Pb-Zn and Mo occurrences imply that all three different types of mineralization in the coastal regions were derived from the post-tectonic granites. Inland, the felsic volcanic rocks solely contain uranium occurrences, in which the uranium mineralization is associated with pyroxene and amphibole-rich layers or disseminations in the host volcanic rocks. The REE patterns of this mineralization are significantly different from those of the coastal occurrences. These occurrences appear to represent syn- to postvolcanic products of hydrothermal leaching of volcanic glasses.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00206610
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