Geology and geochronology of Helikian magmatism, western Labrador

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doi: 10.1139/e81-113
Authors:Brooks, Christopher; Wardle, Richard J.; Rivers, Toby
Author Affiliations:Primary:
Univ. Montreal, Dep. Geol., Montreal, QC, Canada
Other:
Newfoundland Dep. Mines and Energy, Canada
Volume Title:Canadian Journal of Earth Sciences Revue Canadienne des Sciences de la Terre
Source:Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre, 18(7), p.1211-1227. Publisher: National Research Council of Canada, Ottawa, ON, Canada. ISSN: 0008-4077
Publication Date:1981
Note:In English with French summary. 39 refs.; illus. incl. 37 anals., 4 tables, geol. sketch maps
Summary:The Shabogamo suite, a predominantly gabbroic series which intrudes into a variety of Archaean, Aphebian, and Helikian units in the Churchill and Grenville provinces of western Labrador, is dated at approx 1375 m.y., using Rb/Sr and Sm/Nd methods. The suite is synchronous with Elsonian magmatism in Labrador. Gabbros of the Shabogamo intrusive suite are emplaced into volcanic and volcaniclastic rocks of the Blueberry Lake group, which are provisionally dated at 1540 + or - 40 m.y. The linear disposition of centres of felsic volcanism in the Grenville Foreland zone approx 1500 m.y. ago is suggestive of a major ensialic rift at least 300 km in length at that time. A twofold magmatic history during the Helikian of this part of Labrador is proposed on the basis of field mapping and geochronological studies. [P.Br.]
Subjects:Absolute age; Alkaline earth metals; Composition; Dates; Gabbros; Genesis; Geochronology; Helikian; Igneous rocks; Isotopes; Magmas; Mesoproterozoic; Metagabbro; Metaigneous rocks; Metals; Metamorphic rocks; Metamorphism; Plutonic rocks; Precambrian; Proterozoic; Rb/Sr; Schists; Sm/Nd; Sr-87/Sr-86; Stable isotopes; Strontium; Upper Precambrian; Canada; Canadian Shield; Churchill Province; Eastern Canada; Grenville Province; Labrador; Newfoundland; North America; Blueberry Lake Group; Evolution; Intrusive rocks; Ratios; Shabogamo Intrusive Suite
Coordinates:N524500 N541000 W0650000 W0671000
Abstract Numbers:82M/0029
Record ID:1982001865
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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