Geochemical, isotopic, and geochronological evidence for subsynchronous island-arc magmatism and terrigenous sedimentation (Predivinsk terrane of the Yenisei Ridge)

• Published in: Russian geology and geophysics Vol. 57; no. 11; pp. 1570 - 1590
• Main Authors: Nozhkin, A.D., Dmitrieva, N.V., Likhanov, I.I., Serov, P.A., Kozlov, P.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2016; Allerton Press
• Subjects: absolute age; Ar/Ar; Asia; Cambrian; chemical composition; Commonwealth of Independent States; dates; Geochemistry; Geochronology; ICP mass spectra; ion probe data; island arcs; isotope ratios; isotopes; LA-ICP-MS dating; Late Precambrian; Lower Cambrian; major elements; mass spectra; metals; metamorphic rocks; metasedimentary rocks; metavolcanic rocks; Nd-144/Nd-143; neodymium; Neoproterozoic; nesosilicates; orthosilicates; P-T conditions; Paleozoic; Precambrian; Predivinsk Terrane; Proterozoic; rare earths; Russian Federation; SHRIMP data; SHRIMP II; Siberian Platform; silicates; Sm-Nd isotopy; Sm/Nd; spectra; stable isotopes; trace elements; upper Precambrian; volcanosedimentary rocks; Yenisei Ridge; zircon; zircon group; Yenisei Ridge; Sm-Nd isotopy; Predivinsk terrane; SHRIMP II; LA-ICP-MS dating; volcanosedimentary rocks; Late Precambrian
• ISSN: 1068-7971; 1878-030X
• DOI: 10.1016/j.rgg.2016.10.004

In this study we present data on the geologic setting, geochemical and isotopic compositions, timing and P-T conditions of metamorphism of Neoproterozoic terrigenous metasediments, and associated island-arc metavolcanics of the Predivinsk terrane of the Yenisei Ridge. Relatively immature terrigenous rocks were eroded from a local source which is associated with island-arc magmatic complexes. The geochronological constraints indicate that the terrigenous rocks were eroded from juvenile crustal sources represented primarily by magmatic rocks, which are similar to those of the Predivinsk terrane. This is supported by a similar range of model ages, positive £Nd values of terrigenous and magmatic rocks, and correspondence between the concordant ages of detrital zircons from metasedimentary rocks (610-640 Ma) and the U-Pb ages of zircons from rhyolites (ca. 620-640 Ma) from two suites within different sequences. The P-T conditions for volcanosedimentary rocks of the Predivinsk terrane correspond to the epidote-amphibolite facies and the transition from epidote-amphibolite to amphibolite facies. The most likely age of metamorphism due to Vendian accretion/collision events is given by Ar-Ar dates of 600-610 Ma.