NEW DATA ON VOLCANISM OF ZHOKHOV ISLAND, DE LONG ARCHIPELAGO, ARCTIC BASIN

Abstract

The De Long Islands form a separate five-island group in the New Siberian Archipelago. Zhokhov Island, like others of the archipelago, rises several tens of meters above the shallow sea floor. The results of our field work establish that Zhokhov Island is covered entirely by flows of porphyritic olivine basalt lava. Our work has established that the volcanism of Zhokhov Island resulted from magmatic activity at fairly deep mantle levels, and that the island itself is a shield-type volcanic structure, formed chiefly by flows of porphyritic olivine basalt of the picritic basalt-alkalic basalt series (in the) Late Cenozoic. The most recent stage of volcanism on the De Long Islands, perhaps, is genetically related to the advance of the spreading Nansen Cordillera (Haeckel Ridge) onto the Eurasian continent, with the formation of an intracontinental rift system on its extension.