Supplementary geological datasets to Halpin et al. (2026) "Ediacaran-Cambrian high-strain melt-present deformation of the Archean Charcot Province, East Antarctica" in AGU Tectonics

Supporting geological data to accompany Halpin et al. "Ediacaran–Cambrian high-strain melt-present deformation of the Archean Charcot Province, East Antarctica” in review with AGU Tectonics. Includes tables of sample details, field observations, whole rock geochemical data, zircon U–Pb data, zircon Hf-isotope data and feldspar Pb–Pb data. These tables are uploaded separately in XLSX format. Abstract for "Ediacaran–Cambrian high-strain melt-present deformation of the Archean Charcot Province, East Antarctica” in review with AGU Tectonics: The assembly of Gondwana involved several Pan-African orogens, although their extension into ice-covered Antarctica remains contentious. Particularly problematic is our understanding of the Kuunga orogenic system in East Antarctica, including its eroded architecture and temporal evolution. The remote Charcot Province, at the easternmost extent of the Antarctic Kuunga Orogen, presents a key opportunity to test recent tectonic models. Here we investigate the geological history of Alligator Island, a rarely visited exposure of the Charcot Province. Field relationships, petrography and zircon U–Pb–Hf geochronology indicate that the Alligator Island migmatitic gneisses originated from a Mesoarchean (c. 2.97–2.95 Ga) volcano-sedimentary package. Metamorphism during the Neoarchean (c. 2.76 Ga) was characterised by channelled melt migration. An apparent tectonic quiescence followed until the Ediacaran–Cambrian (580–540 Ma) when high-strain melt-present deformation led to pervasive migmatitic textures and tight folding. Zircon Hf isotopic signatures from anatectic 580–540 Ma grains indicate that melt was sourced from crust older than 3.0 Ga. Melt metasomatism affected whole rock chemistry and feldspar Pb–Pb compositions highlighting complex interactions within the crust. Correlations within the Charcot Province suggest that Alligator Island's Mesoarchean volcano-sedimentary package was deposited on a basement complex possibly represented by Paleo-Mesoarchean gneisses exposed 40–60 km to the east at Cape Charcot and Davis Peninsula. Overall our findings are consistent with a recent model in which Charcot Province rocks formed through gravitational spreading within the Kuunga orogenic system during Gondwana assembly, and enhance our understanding of the tectonic processes shaping East Antarctica.