Proterozoic flood basalts from the Coppermine River area, Northwest Territories: isotope and trace element geochemistry

• Published in: Canadian Journal of Earth Sciences
• Main Authors: Dupuy, C., Michard, A., Dostal, J., Dautel, D., Baragar, W. R. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1992
• Subjects: Coppermine River; Northwest Territories
• Online Access: http://dx.doi.org/10.1139/e92-151; http://www.nrcresearchpress.com/doi/pdf/10.1139/e92-151

The voluminous Proterozoic continental tholeiites of the Coppermine River province (Northwest Territories), which are coeval with the Mackenzie magmatic event (1.27 Ga old) and were emplaced over a short period of time (< 5 Ma), have trace element and Sr–Nd–Pb isotopic characteristics comparable to those of Phanerozoic flood basalts. The variations of the compositional parameters are inferred to be due to a mixing of at least two components: mantle and crust. In addition, the mantle component probably includes two end members. The first is a mantle plume, whereas the other represents the base of the continental lithosphere. The crustal component reflects contamination of the magma by Precambrian basement during its ascent to the surface.