A Mid-Mesozoic Breccia from the Coast of Labrador

A unique occurrence of Mesozoic breccia cut by lamprophyric-carbonatite dikelets, near Makkovik, Labrador is interpreted to relate to the opening of the Labrador Sea. The breccia has been dated by nannofossils; vitrinite reflectance studies show that some time during or after deposition the rock was...

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Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Authors: King, A. F., McMillan, N. J.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1975
Subjects:
Online Access:http://dx.doi.org/10.1139/e75-005
http://www.nrcresearchpress.com/doi/pdf/10.1139/e75-005
Description
Summary:A unique occurrence of Mesozoic breccia cut by lamprophyric-carbonatite dikelets, near Makkovik, Labrador is interpreted to relate to the opening of the Labrador Sea. The breccia has been dated by nannofossils; vitrinite reflectance studies show that some time during or after deposition the rock was heated to at least 170 °C. It is suggested that shallow seas extended westward beyond the present Labrador Marginal Trough during early Jurassic time and that the period of late alkaline igneous activity is related to the rifting between Greenland and Labrador that commenced about the middle of the Mesozoic Era.