Paleomagnetism of cryogenian kitoi mafic dykes in south siberia: Implications for neoproterozoic paleogeography

摘要

We present a new paleomagnetic pole of 1.1°N, 22.4°E, A_(95)=7.4° from the 760Ma gabbro-dolerite Kitoi dykes located in the southern part of the Siberian Craton. The pole is supported by contact tests and suggests closer position of Siberia relative to Laurentia at 760Ma than in Mesoproterozoic. We propose that this closer configuration was achieved by dextral transpressive motion of Siberia relative to Laurentia between 780 and 760Ma. This motion was probably initiated at the first stage of the Rodinia breakup and is coeval with the 780Ma Gunbarrel magmatic event of the western Canadian shield.