TY - JOUR

T1 - Low-grade Sandow Group metasediments of the Denman Glacier area (East Antarctica)

T2 - Chemical composition, age and provenance from U–Pb detrital zircon data, with some palaeotectonic implications

AU - Mikhalsky, E. V.

AU - Tkacheva, D. A.

AU - Skublov, S. G.

AU - Leitchenkov, G. L.

AU - Rodionov, N. V.

AU - Kapitonov, I. N.

AU - Kunakkuzin, E. L.

N1 - Funding Information: This research was supported by the Russian Foundation for Basic Research grants No 10-05-00624 to GLL and 11-05-00254 to EVM. The research was partly supported by the IPGG RAS (project 0153-2019-0002 ). Publisher Copyright: © 2020 Elsevier B.V. and NIPR Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12

Y1 - 2020/12

N2 - The Sandow Group in the Denman Glacier area consists of low-grade supracrustal (post-cratonic) strata. Such rocks are scarce and poorly studied in East Antarctica, but are significant for a better understanding of the geological history and tectonic evolution of the Precambrian supercontinents. We report U–Pb (LA-ICP-MS) detrital zircon ages which mostly fall into two groups of ca 1350−900 Ma and ca 1800−1500 Ma, which correspond to those of crystalline rocks exposed in the western Australo-Antarctica. The youngest zircons with magmatic zoning yield ages of ca 950–900 Ma which define the maximum age of sedimentation. Chemical and neodymium isotopic compositions of the Sandow Group rocks indicate derivation from a Proterozoic largely granitic source region. High-Ti mafic volcanic activity accompanied sedimentation, and therefore the Sandow Group should be considered a volcanic-sedimentary succession. The Sandow Group was presumably accumulated in a continental (pull-apart?) basin formed in the Neoproterozoic in relation to proto-Darling Fault system activity with its continuation into Antarctica. The Sandow Group may have its correlatives in Western Australia where sedimentary successions (e.g., Moora and Badgeradda Groups) occur along the proto-Darling Fault system.

AB - The Sandow Group in the Denman Glacier area consists of low-grade supracrustal (post-cratonic) strata. Such rocks are scarce and poorly studied in East Antarctica, but are significant for a better understanding of the geological history and tectonic evolution of the Precambrian supercontinents. We report U–Pb (LA-ICP-MS) detrital zircon ages which mostly fall into two groups of ca 1350−900 Ma and ca 1800−1500 Ma, which correspond to those of crystalline rocks exposed in the western Australo-Antarctica. The youngest zircons with magmatic zoning yield ages of ca 950–900 Ma which define the maximum age of sedimentation. Chemical and neodymium isotopic compositions of the Sandow Group rocks indicate derivation from a Proterozoic largely granitic source region. High-Ti mafic volcanic activity accompanied sedimentation, and therefore the Sandow Group should be considered a volcanic-sedimentary succession. The Sandow Group was presumably accumulated in a continental (pull-apart?) basin formed in the Neoproterozoic in relation to proto-Darling Fault system activity with its continuation into Antarctica. The Sandow Group may have its correlatives in Western Australia where sedimentary successions (e.g., Moora and Badgeradda Groups) occur along the proto-Darling Fault system.

KW - Antarctica

KW - Detrital zircon age

KW - Neoproterozoic

KW - Pull-apart basin

KW - Sedimentation

UR - http://www.scopus.com/inward/record.url?scp=85090703298&partnerID=8YFLogxK

U2 - 10.1016/j.polar.2020.100587

DO - 10.1016/j.polar.2020.100587

M3 - Article

AN - SCOPUS:85090703298

VL - 26

JO - Polar Science

JF - Polar Science

SN - 1873-9652

M1 - 100587

ER -