ANCIENT HIT-AND-RUN: A TRANSIENT PALEOPROTEROZOIC PALEOMAGNETIC CONNECTION BETWEEN THE VESTFOLD HILLS AND PROTO-INDIA

Extending the plate tectonic record back in time requires comprehensive geological data from all continents. The Precambrian paleomagnetic record of Antarctica is remarkably barren due to difficulty accessing the continent and limited exposure of outcrop. The Vestfold Hills area of East Antarctica – a dry, generally ice-free valley – provides a unique window of access into the early tectonic history of this high metamorphic grade terrane northeast of the Rauer Group in the Prydz Bay region. Numerous well-exposed Proterozoic mafic dykes in the Vestfold Hills offer an excellent target for paleomagnetic research constraining its movement through time. A single pilot paleomagnetic study has been carried out in this area by Embleton and Arriens (1971). Geochronological studies of these dykes swarms show them as episodic in nature, yet have not robustly defined the ages. Here we report new paleomagnetic and rock magnetic results from mafic dykes of the Vestfold Hills. Three dykes with similar paleomagnetic signatures (when rotated to an Indian reference frame) closely resemble 2.18 Ga paleomagnetic signatures from the Dharwar craton/northern Southern Granulite Terrane in India. Other stable paleomagnetic data from the Vestfold Hills may compare with proposed neighbors throughout the Proterozoic. Further paleomagnetic and geochronologic research is needed to adequately average paleosecular variation and confidently assign ages to the paleomagnetic data. These results show the remarkable but underutilized potential of the Vestfold Hills as a window into Precambrian tectonics.