New constraints on metamorphism and crustal evolution of the Isua Supracrustal Belt and neighbouring gneisses, southwest Greenland

Abstract

This thesis investigates the polymetamorphic rock record of the Isua Supracrustal Belt and surrounding Eoarchean gneisses in southwest Greenland using petrography and in situ Lu–Hf garnet geochronology. It unravels the pressure–temperature–time (P–T–t) record of Eoarchean granulite-facies metamorphism and synthesizes a more complete metamorphic history by integrating literature and new age constraints on later events, further including an apatite–within–zircon inclusion study focused on recovering Eoarchean isotopic signatures.