Publication Date:
2014-01-01
Description:
The Central Taimyr accretionary belt includes two granite-metamorphic terranes: Faddey and Mamont-Shrenk, which include the oldest igneous formations of the Taimyr folded area in the Arctic framing of the Siberian craton-granitoids and granite-gneisses with U-Pb zircon ages of 900-830 Ma. The [FeO*/(FeO* + MgO)]-enriched granitoids of these terranes are products of highly fractionated I-type magmas. This paper presents results of new petrographic, geochemical, geochronological, and paleomagnetic investigations of acid rocks from a volcanic-plutonic association (in the region of the Leningradskaya River) in the Faddey terrane in the northeastern Taimyr area. These rocks formed during the final stage of continent-island arc accretion and collision that occurred at approximately 870-820 Ma. We established that the studied rocks belong to a long granitoid belt extending from Mamont-Shrenk to Faddey terrane, where all the igneous bodies are deformed and oriented uniformly. The paleomagnetic pole we calculated differs significantly from the apparent polar-wander path interval of corresponding age for Siberia. The 33.8° ± 5.4° angular distance between the poles indicates that the formation of this volcanic-plutonic association took place at a significant distance from the Taimyr margin of the Siberian paleocontinent. © 2014 V.S. Sobolev IGM, Siberian Branch of the RAS.
Print ISSN:
1068-7971
Electronic ISSN:
1878-030X
Topics:
Geosciences
,
Physics
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