Cretaceous Magmatism South and East of Svalbard: Evidence from Seismic Reflection and Magnetic Data

Abstract

In the Svalbard archipelago, late Mesozoic magmatic rocks in the form of basaltic sills and dykes are recorded from the land areas between central and eastern Spitsbergen and the Hinlopen Strait.In addition, tholeiitic f100d basalts are identified on Kong Karls Land, where they typically form the summit plateaus ofthe main islands, and in Pranz Josefs Land in the Russian Arctic.Seismic mapping, combined with the forward modelling of magnetic anorna- lies, has revealed the cxtcnt of the magmatic province in the offshore area to the south and east of Svalbard.Sills and dykes are identified within sedirnentary sequences of Penno-Carboniferous, Triassie, Jurassie.and Cretaceous age.The evolution of the basalt province was related to the initial brcak-up of the Eurasian-Laurentian supercontinent.This event involveel extension anel volcanism associated with the opening of the Canada Basin and subsequent formation of the basaltic Alpha Ridge, presently situateel in the Arctic Ocean.The mapping of this province has important implications for the thermal evolution of petroleum source rocks, and the evaluation of the hydrocarbon potential of the northern Barents Sea.