IMPLICATIONS FOR GONDWANA OF NEW ORDOVICIAN PALEOMAGNETIC DATA FROM IGNEOUS ROCKS IN SOUTHERN VICTORIA LAND, EAST ANTARCTICA

New paleomagnetic data presented here from the southern Victoria Land (SVL) region of East Antarctica further refine the Gondwana early Pale ozoic apparent polar wander path. The results are based on paleomagnet ic analyses of Early to Middle Ordovician granitoids and dike swarms f rom which a new SVL pole (23 degrees E, 3.5 degrees S, A95=5.9 degrees ) was calculated. The new SVL paleomagnetic pole agrees with less well -determined Ordovician poles from other parts of East Antarctica indic ating little or no translation/rotation across the East Antarctic crat on since the Middle Ordovician. A new Gondwana similar to 475 Ma mean pole (11 degrees E, 36 degrees N, A95=7 degrees, N=4 studies, in Afric an coordinates) has been calculated from African, Australian, and Anta rctic Early and early Middle Ordovician paleomagnetic poles. Age reass ignment of the Antarctic Sor Rondane paleopole (Zijderveld, 1968) plac es it into the Cambrian period and when combined with other Gondwana C ambrian poles results in a new Gondwana similar to 515 Ma pole (7 degr ees E, 22 degrees N, A95=9.5 degrees, N=7 studies, in African coordina tes). The new Gondwana similar to 515 Ma and similar to 475 Ma poles, when compared with poles of similar age from Laurentia, allow paleogeo graphic reconstructions to be made that are in keeping with models pre dicting that Iapetus Ocean basin opening and closure may Rave been rel ated first to rifting and then collision of Laurentia with Gondwana. T he paleomagnetic data also suggest that most of West Gondwana moved to ward lower latitudes between the Middle/Late Cambrian and the late Ear ly Ordovician which may be reflected in the fossil record.