2.7 Ga high-pressure granulites of the Teton Range: Record of Neoarchean continent collision and exhumation

Continent-continent collisional orogens are the hallmark of modern plate tectonics. The scarcity of well-preserved high-pressure granulite facies terranes minimally obscured by later tectonic events has limited our ability to understand how closely Archean tectonic processes may have resembled betterunderstood modern processes. Here we describe Neoarchean gneisses in the Teton Range of Wyoming, USA, that record 2.70 Ga high-pressure granulite facies metamorphism, followed by juxtaposition of gneisses with different protoliths, and then by intrusion of leucogranites generated through decompression melting in response to post-collisional uplift. This evidence is best explained as the result of a 2.70–2.68 Ga Himalayan-style orogeny, and suggests that, although subduction may have been occurring earlier in the Archean, doubling of continental thickness by continent-continent collisions may date back to at least 2.7 Ga.