Proterozoic mafic magmatism in Siberian craton: An overview and implications for paleocontinental reconstruction

• We present a summary of late Paleoproterozoic to Neoproterozoic mafic magmatism in the Siberian craton, including recently published U-Pb and Ar-40-Ar-39 dates. These new precise ages suggest that at least some of the previously published K-Ar ages of Siberian mafic bodies should be ignored. The time-space geochronological chart, or the 'barcode' of mafic magmatic events shows significant differences between northern and southern Siberia. Both are characterized by similar to 1900-1700 Ma magmatic events, but then there was an almost 1 Ga mafic magmatic 'pause' in south Siberia until similar to 800 Ma. Meanwhile there are indications of multiple mafic magmatic events in North Siberia (Anabar shield and Olenek uplift) between similar to 1600 and 1000 Ma. A series of magmatic events probably related to the breakup of Rodinia occurred in southern Siberia after similar to 800 Ma. So far, there are no indications of late Neoproterozoic mafic magmatism in North Siberia. Ca. 1000-950 Ma mafic sills were reported from Meso- to Neo-Proterozoic sedimentary successions in the Sette-Daban area on the east side of the Siberian craton, but their tectonic setting is debated. Recent Ar-Ar dates of similar to 1750 Ma for NW-trending dykes in the Aldan and Anabar shields, together with similar-age NNE-trending Baikal uplift dykes in south-eastern Siberia suggest the existence of a giant radial dyke swarm possibly related to a mantle plume centred in the Vilyui River area. (C) 2010 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

Nyckelord

Geochronology

Dykes

Mafic magmatism

Proterozoic

Siberian craton

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