Early Cretaceous paleomagnetic results from Marie Byrd Land, West Antarctica: implications for the Weddellia collage of crustal blocks

A new ~117 Ma paleomagnetic pole has been defined from the study of volcanic and plutonic rocks from the eastern portion Marie Byrd Land. The new pole implies that the eastern portion of MBL was an integral part of Weddellia. This pole is generally similar to a ~125 Ma pole from Thurston Island. Both poles call for major clockwise rotation and poleward motion of eastern MBL and Thurston Island between the Early Cretaceous and the mid-Cretaceous. It is proposed that in the Early Cretaceous, eastern MBL and the Eastern Province of New Zealand were part of a continuous active Pacific margin of Gondwana, connecting with the Antarctic Peninsula, and distinct from western MBL, the Western Province of New Zealand, and North Victoria Land. These western terranes are thought to have accreted to Gondwana in the Devonian. Eastern MBL and the Eastern Province of New Zealand amalgamated with western MBL and the Western Province of New Zealand by the mid-Cretaceous. -from Authors