In the central and southwestern Grenville province in Canada and the northeastern United States, anorthosites and related granitoids were emplaced during two distinct pulses, at ca. 1.16–1.13 Ga and 1.09–1.05 Ga, each following major crustal thickening events. U-Pb age constraints on movement along major ductile shear zones indicate that they were emplaced within extending crust in an overall convergent orogen. We suggest that convective thinning of the lithosphere played a significant role in their emplacement and in the tectonic evolution of the Grenvillian orogeny.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.