Инд. авторы:	Shatsky V.S., Skuzovatov S.Y, Malkovets V.G, Belousova E.A.
Заглавие:	Evolution history of the neoproterozoic eclogite-bearing complex of the muya dome (central asian orogenic belt): constraints from zircon u-pb age, hf and whole-rock nd isotopes
Библ. ссылка:	Shatsky V.S., Skuzovatov S.Y, Malkovets V.G, Belousova E.A. Evolution history of the neoproterozoic eclogite-bearing complex of the muya dome (central asian orogenic belt): constraints from zircon u-pb age, hf and whole-rock nd isotopes // Precambrian Research. - 2015. - Vol.261. - P.1-11. - ISSN 0301-9268.
Внешние системы:	DOI: 10.1016/j.precamres.2015.01.013; РИНЦ: 24009031; SCOPUS: 2-s2.0-84923092002; WoS: 000352680500001;
Реферат:	eng: U-Pb dating and Hf-isotope analysis of zircons and whole-rock Nd-isotope analyses were carried out on country rocks of the eclogite-gneiss complex of the North Muya dome in the Anamakit-Muya zone of the Baikal Muya accretionary fold belt. Zircons from garnet-biotite gneisses (Qtz+Kfsp+Pl+Bt+Grt) and garnet-biotite-muscovite schist (Pl+Kfsp+Bt+Mu+Grt+Qtz) were dated using the LA-ICP-MS technique. Based on U-Pb isotope data and CL images zircon grains were divided into three groups: detrital, magmatic and metamorphic zircons. Metamorphic zircons display no zoning or the cloudy zoning. The grains morphology together with the well-developed oscillatory zoning clearly identifies the igneous origin of magmatic zircons. The metamorphic zircons (ages 576-680Ma) have Th/U ratios varying from 0.271 to 0.004, whereas the ratio in magmatic zircons ranges from 0.779 to 0.11. Magmatic zircons from granite-gneisses of the North Muya dome exhibit a relatively narrow spread in the crystallization age with the major peak at ca 764Ma. Younger ages are interpreted as due to the partial resetting of U-Pb system during the subsequent metamorphic evolution. Detrital zircons from two-mica schist sample Mu-93-10 give ages of 1.88-2.66Ga. The oldest detrital zircon from this sample plots near concordia and has a 207Pb/206Pb age of 3.2Ga. Zircons from this sample are characterized by the widest scatter of eHf(t) values (from +13.9 to -15.3) and TCDM model ages (0.82-3.86Ga). Zircons from other samples have a much narrower ranges of eHf(t) (+11.6 to -0.7) and TCDM (0.85-1.52Ga). The involvement of older crustal material is also evident from the whole-rock Nd isotopic compositions. The gneisses and schists exhibit a range of Nd isotopic compositions with eNd(t) values ranging from -3.5 to +3.6 and tNd(DM) from 1.64 to 1.09Ga. The integration of the Hf-isotope data with the age spectra provides with the first evidence for the existence of Mesoarchean crust in the Baykal-Muya sector of the Central Asian Orogenic Belt. © 2015 Elsevier B.V.
Ключевые слова:	zircon; uranium-lead dating; subduction; Proterozoic; orogenic belt; neodymium isotope; isotopic analysis; hafnium; gneiss; eclogite; country rock; Zircon; U-Pb dating; Hf isotopes; Continental subduction; Central Asian Orogenic Belt; Central Asia;
Издано:	2015
Физ. характеристика:	с.1-11