Unraveling the Cooling History of Granulites From Grovnes Peninsula, Larsemann Hills, East Antarctica: Insights From Garnet Diffusion Speedometry

Deciphering the cooling rates of metamorphic rocks is critical in characterizing the kinematics of orogenesis as well as in understanding heat transport regimes. Although thermochronology is competent enough to unravel such processes, the application of solid‐state diffusion speedometry is also an excellent tool in the cooling rate estimation of high‐temperature metamorphic rocks. The present study attempts to constrain the cooling rate of a garnetiferous felsic gneiss from the Grovnes Peninsula of Larsemann Hills, East Antarctica using garnet diffusion speedometry. Our new results combined with existing thermochronological data identify a three‐stage differential cooling pattern for the studied sample. The estimated average cooling rates are 60–70°C/Ma between 750°C and 600°C followed by 13–15°C/Ma between 600°C and 450°C and 4–6°C/Ma between ∼450°C and 345°C–285°C. The initial faster cooling rates can be ascribed to domination of tectonically derived exhumation processes whereas the final slow cooling rates can be attributed to the prevalence of erosion‐assisted exhumation processes.