Portal de Periódicos da CAPES

Neoproterozoic Orogeny along the margins of Siberia

2004; Zoological Society of London; Volume: 30; Issue: 1 Linguagem: Inglês

10.1144/gsl.mem.2004.030.01.18

2041-4722

V. A. Vernikovsky, A. E. Vernikovskaya, Victoria Pease, David G. Gee,

Geochemistry and Geologic Mapping

Abstract The Siberian Craton is bounded by fold-and-thrust belts involving Neoproterozoic (locally Mesoproterozoic) complexes on the southern (Baikal-Vitim), western (Yenisey Ridge and Turukhansk-Igarka), northern (Taimyr), and eastern (Verkhoyansk) sides. This paper focuses on the geological structure and evolution of these formations. Previous and new geochronological data show that passive continental margins existed around most of the Siberian Craton during the early Neoproterozoic and possibly the late Mesoproterozoic. Between about 850–760 Ma, the southern, western and northern passive margins of the Siberian Craton were transformed into active margins. Middle-late Neoproterozoic island arcs and ophiolites were formed between c. 750–650 Ma along these margins; they are inferred to have been obducted onto the Siberian continental margin at c. 600 Ma, prior to late Vendian deposition. New ion microprobe U-Pb ages of ophiolitic rocks from Taimyr’s Central domain are presented. The Neoproterozoic record in the Cretaceous Verkhoyansk fold-and-thrust belt indicates that the eastern part of the Siberian Craton remained a passive continental margin during the Neoproterozoic and Palaeozoic. Baltica-Siberia relationships are also discussed.