The multistage history of the Queen Maud Batholith, La Gorce Mountains, central Transantarctic Mountains

This study reports U-Pb ages and the whole-rock geochemistry of a group of granitoids and metavolcanics related to the Ross Orogen in the La Gorce Range of the central Transantarctic Mountains. SHRIMP U/Pb dating reveals complex zircon populations in granites ranging in age from 540 to 480 Ma, with major pulses between 536 and 513 Ma. The metavolcanic Wyatt Formation shows simpler zircon systematics with a magmatic age of 526 ± 4 Ma and minor Pb loss. This age also exists in a Szabo Bluff granite, an indication that plutonic and volcanic rocks were emplaced at the same time. High-K, calc-alkaline geochemical trends link the igneous units together as a highly evolved granitic suite or supersuite that may represent transpressional magmatism along the Paleozoic Pacific margin of Gondwana. (author). 16 refs., 3 figs., 1 tab