GSA Today
Volume 30, Issue 12

Cover image

Typical coarse-grained to pegmatitic, orthopyroxene-bearing anorthosite (leuconorite) from the 1765–1630 Ma Mealy Mountains Intrusive Suite (Labrador, Canada). This Mesoproterozoic anorthosite massif intrudes the Mealy Mountains Terrane and is one of several classic intrusive complexes in the Grenville Province of eastern North America. The hammer is ~40 cm long. Photo courtesy of Grant Bybee, Univ. of the Witwatersrand.

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