科研之友
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摘要
This paper is a summary of the geological and geophysical information available today on the tectonics of the Arctic continental structures in the Late Precambrian-Paleozoic. We propose a new outlook on the history of Arctida - a continental mass that combined sialic blocks of the current Eurasian shelf of the Arctic Ocean. Based on new materials including paleomagnetic data we present a series of paleotectonic reconstructions that reflect the main evolutionary stages and mechanisms of the structure of Arctida from the Early Neoproterozoic to the Mesozoic. We demonstrate the role of the continental blocks of the Arctic in the global drift of lithospheric plates from the breakup of Rodinia to the assembly of Pangea. From the presented model we propose the existence of two (!) Arctic subcontinents in the Neoproterozoic-Paleozoic history of the Earth. Arctida-I was a collage of ancient blocks of Arctic sialic crust within Rodinia in the junction zone between the Laurentia, Siberia and Baltica cratons. During the breakup of Rodinia this subcontinent was destroyed with the formation of a series of small continental plates such as Kara, Svalbard and, probably, the New Siberian Islands (NSI), which is usually regarded as part of the Chukchi-Alaska composite terrane. By the time of its breakup Arctida-I was in a subequatorial position. The post-rifting tectonics of the newly formed small plates was closely associated with strike-slips that played a defining role both at the stages of opening and closure of the Paleozoic oceans. The rebirth of Arctida was due to the assembly of Pangea at the Paleozoic-Mesozoic limit. We consider Arctida-II a newly formed subcontinent that composed the shelf margin of Pangea in the temperate latitudes of the northern hemisphere, and again connected the margins of Laurentia, Baltica and Siberia.
- 出版日期2015-4
