11. Field Relations of Granite Harbour Intrusives and Associated Dikes from the USARP Mountains, North Victoria Land, and Prince Al­ bert Mountains, Central Victoria Land, Antarctica

Two suites of Paleozoic intrusives are distinguished in the Transantarctic Mountains, i.e., the Cambrian to early Ordovician Granite Harbour Intrusives (GUNN & WARREN 1962) and the Devonian to early Carboniferous Admiralty Intrusives (HARRINGTON 1958; redefined by GRINDLEY & WARREN 1969). Whereas granitoids of the Admiralty Intrusives are restricted to North Victoria Land (see HENJES-KUNST this vol.) intrusives of the Granite Harbour Intrusives suite are widely distributed in a belt that runs along the edge of the Polar Plateau from the Pacific coast of North Victoria Land to the Weddell Sea (GANOVEX-TEAM 1987). Forming abundant synto post-tectonic plutons and batholiths they represent the c1earest manifestation of the early Paleozoic Ross Orogeny in western Antarctica. Geochemically, the Granite Harbour Intrusives are gabbros to granites of calcalkaline affinity indicative of a forrner active continental-margin setting (BORG et al. 1987, BORG et al. 1990, see KLEINSCHMIDT & TESSENSOHN 1987).