Apatite fission track and (U-Th-Sm)/He thermochronology of in-situ bedrock, western Marie Byrd Land, West Antarctica

Here we present the first apatite (U-Th-Sm)/He data from the Devonian Ford Granodiorite and the mid-Cretaceous Byrd Coast Granite suites from the Ford Ranges and the Edward VII Peninsula.

Thermal history modeling integrating apatite (U-Th-Sm)/He dates of 109–68 Ma with revised apatite fission track data in combination with geologic information indicates a thermal history with diachronous enhanced cooling at ~100–60 Ma and subsequent slow cooling until the present-day. Enhanced cooling at ~100–70 Ma was related to activity of the West Antarctic rift system and to continental breakup, thereby exhuming most samples to shallow crustal levels.