Evolution of the ca. 1.9 gallium Taltson magmatic zone, Northwest Territories: A neodymium isotope perspective.

• Main Author: Thériault, Réginald J.
• Other Authors: Lalonde, A. E.
• Format: Thesis
• Language: unknown
• Published: University of Ottawa (Canada) 1990
• Subjects: Geochemistry; Northwest Territories
• Online Access: http://hdl.handle.net/10393/5788; https://doi.org/10.20381/ruor-14537

The Taltson magmatic zone is a north-trending belt of Early Proterozoic granitoids exposed over an area exceeding 18,000 km$\sp2$ in the Northwest Territories. Three petrologically and chronologically distinct intrusive suites comprise the Taltson zone. These are the 1986 Ma Deskenatlata suite, the 1955 to 1925 Ma Slave suite and the 1935 Ma Konth suite. The Deskenatlata suite is composed of a biotite-hornblende diorite to granite suite whose major and trace element chemistry supports derivation by arc magmatism. The Slave and Konth suites are leucocratic granitoids which contain numerous xenoliths of dominantly pelitic high grade paragneiss and display S-type granite mineralogy which commonly duplicates that of the pelitic gneisses. Bulk rock chemistry for the Konth suite is consistent with a homogeneous crustal magma source whereas the Slave suite is compositionally more heterogeneous. The Deskenatlata suite is considered as continental arc-derived granitoids resulting from eastward subduction of oceanic lithosphere beneath the Churchill Province. The Slave suite is regarded as the result of melting of various segments of heterogeneous Archean crust whereas the Konth may have evolved exclusively from melting of pelitic metasediments. (Abstract shortened by UMI.)