TY - JOUR

T1 - U-Pb age of zircon from paragneisses in granulite terrane of the Sharyzhalgai uplift (southwest of the Siberian craton)

T2 - Evidence for the Archean sedimentation and evolution of continental crust from Eoarchean to Mesoarchean

AU - Turkina, O. M.

AU - Sergeev, S. A.

AU - Sukhorukov, V. P.

AU - Rodionov, N. V.

PY - 2017/9/1

Y1 - 2017/9/1

N2 - The Archean stage of sedimentation has been first substantiated for the granulite-gneiss terranes of the Sharyzhalgai uplift (southwest of the Siberian craton). High-alumina paragneisses contain detrital zircons varying in age from 3.7 to 2.74 Ga and corresponding in REE patterns to magmatic zircons. The Paleoproterozoic (~ 1.86 Ga) metamorphic zircons are strongly depleted in HREE and Y as a result of their formation in equilibrium with garnet. Zircons with an age of ~ 2.5 Ga also show geochemical signs of alteration during metamorphism. The formation of terrigenous sedimentary rocks preceded the Neoarchean stage of magmatism (~ 2.7-2.6 Ga), and their metamorphism occurred at the Neoarchean-Paleoproterozoic boundary and in the Late Paleoproterozoic. The sources of detrital zircons were mainly Mesoarchean rocks, such as magmatic protoliths of granulites and intermediate-felsic magmatic rocks. The single Eoarchean and Paleoarchean detrital zircon grains in the paragneisses are the first direct evidence for the oldest crust (up to 3.7 Ga) in the granulite terranes of the Sharyzhalgai uplift. The set of geochronological data for granulites and paragneisses suggests the following sequence of geologic events for the granulite-gneiss terranes: ~ 3.7—the beginning of crustal formation, 3.4-3.2 Ga—intermediate-felsic magmatism, including the recycling of the more ancient crust, and ~ 3.0 Ga—coeval magmatic and metamorphic processes and differentiation of the continental crust. Thus, the whole cycle from the beginning of crustal growth to the crustal differentiation and turn into continental crust proceeded from 3.7 to 3.0 Ga.

AB - The Archean stage of sedimentation has been first substantiated for the granulite-gneiss terranes of the Sharyzhalgai uplift (southwest of the Siberian craton). High-alumina paragneisses contain detrital zircons varying in age from 3.7 to 2.74 Ga and corresponding in REE patterns to magmatic zircons. The Paleoproterozoic (~ 1.86 Ga) metamorphic zircons are strongly depleted in HREE and Y as a result of their formation in equilibrium with garnet. Zircons with an age of ~ 2.5 Ga also show geochemical signs of alteration during metamorphism. The formation of terrigenous sedimentary rocks preceded the Neoarchean stage of magmatism (~ 2.7-2.6 Ga), and their metamorphism occurred at the Neoarchean-Paleoproterozoic boundary and in the Late Paleoproterozoic. The sources of detrital zircons were mainly Mesoarchean rocks, such as magmatic protoliths of granulites and intermediate-felsic magmatic rocks. The single Eoarchean and Paleoarchean detrital zircon grains in the paragneisses are the first direct evidence for the oldest crust (up to 3.7 Ga) in the granulite terranes of the Sharyzhalgai uplift. The set of geochronological data for granulites and paragneisses suggests the following sequence of geologic events for the granulite-gneiss terranes: ~ 3.7—the beginning of crustal formation, 3.4-3.2 Ga—intermediate-felsic magmatism, including the recycling of the more ancient crust, and ~ 3.0 Ga—coeval magmatic and metamorphic processes and differentiation of the continental crust. Thus, the whole cycle from the beginning of crustal growth to the crustal differentiation and turn into continental crust proceeded from 3.7 to 3.0 Ga.

KW - Archean

KW - detrital zircon

KW - paragneisses

KW - sedimentation

KW - Sharyzhalgai uplift

KW - SHRIMP

KW - U-Pb age

KW - METAMORPHIC EVENTS

KW - METASEDIMENTARY ROCKS

KW - DETRITAL ZIRCON

KW - GNEISS BLOCK

KW - PALEOPROTEROZOIC AGE

KW - LU-HF ISOTOPE

KW - IRKUT BLOCK

KW - METATERRIGENOUS ROCKS

KW - PLATFORM BASEMENT

KW - SILLIMANITE SCHIST DEPOSIT

UR - http://www.scopus.com/inward/record.url?scp=85031740874&partnerID=8YFLogxK

U2 - 10.1016/j.rgg.2016.07.007

DO - 10.1016/j.rgg.2016.07.007

M3 - Article

AN - SCOPUS:85031740874

VL - 58

SP - 1018

EP - 1031

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 9

ER -