Petrology and Nd-Hf isotope geochemistry of the neoproterozoic amon kimberlite sills, Baffin Island (Canada): Evidence for deep mantle magmatic activity linked to supercontinent cycles

Abstract

The c. 673 Ma (U-Pb rutile) Amon kimberlites located in northern Baffin Island intruded Late Archean basement rocks of the Rae craton as a subhorizontal sill complex. The Amon sills are part of widespread low-volume, volatile-rich ultramafic magmatism that occurred along the northern and eastern margins of Laurentia, demarcating the temporal and spatial breakout from the Rodinia supercontinent during the Late Neoproterozoic. Numerous other known kimberlite occurrences that are related to these rifting events between c. 680 and 540 Ma are located in mainland Nunavut, Ontario, Quebec, Labrador, and West Greenland. The magmas that fed the Amon sills are archetypal Group-I kimberlites, based on ..