CaltechAUTHORS
  A Caltech Library Service

Microstructures documenting Cenozoic extension processes in the northern continental margin of the South China Sea

Sun, Liheng and Sun, Zhen and Huang, Xiaolong and Jiang, Yingde and Stock, Joann Miriam (2019) Microstructures documenting Cenozoic extension processes in the northern continental margin of the South China Sea. International Geology Review, 62 (7-8). pp. 1094-1107. ISSN 0020-6814. https://resolver.caltech.edu/CaltechAUTHORS:20191017-132811087

[img] Archive (ZIP) - Supplemental Material
See Usage Policy.

41Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20191017-132811087

Abstract

In order to investigate the thinning process of the northern continental margin of the South China Sea, petrographic and microstructural analysis were carried out on 20 greenschistfacies mylonite samples, which were obtained from Site U1504 of IODP Expedition 367/368 in the Outer Margin High of the region. The mineral assemblage of the greenschist-facies mylonite is chlorite + epidotite + albite (Ab = 94.7–99.9) + quartz, which contains 10-30% gravel components. Microstructural analysis indicates that the greenschist-facies mylonite experienced two episodes of deformation:early ductile deformation followed by a later stage of brittle deformatio. Both episodes of deformation suggest an extensional environment. The extensive development of bulging recrystallization (BLG) of quartz, microscopic fractures and fine granulation of albite suggest that the temperature of ductile deformation is about 300-400°C, compatiable with a ductile shearing at shallow crust levels (~5-10 km). Petrographic features suggest that the greenschist-facies mylonite might originate from volcanic sedimentary rocks or sedimentary rocks affected by the intrusion of mafic magma. Combined with seismic interpretation, we propose that the greenschist-facies mylonite might be formed by crustal exhumation after thick Mesozoic sediments were denuded by a major extension.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1080/00206814.2019.1669079DOIArticle
ORCID:
AuthorORCID
Stock, Joann Miriam0000-0003-4816-7865
Additional Information:© 2019 Taylor & Francis. Received 04 Mar 2019, Accepted 14 Sep 2019, Published online: 29 Sep 2019. This work was supported by the Natural Science Foundation of Guangdong Province [2017A030312002]; K.C. Wong Education Foundation [GJTD-2018-13]; IODP-China and South China Sea Deep Project [91628301]. CAS P.I.F.I. visiting professor project [2019VMA0002]; National Natural Science Foundation of China [41576070, 41625007]; . This project used samples or data from the JOIDES Resolution Science Operator of the International Ocean Discovery Program, a large facility funded by the US National Science Foundation. This research was supported by the research team project of Guangdong Natural Science Foundation (2017A030312002), K.C.Wong Education Foundation (GJTD-2018-13), South China Sea Deep Project (91628301), Guangdong Special Support Program to Y. D. J., CAS P.I.F.I. visiting professor project to J. M. S. (2019VMA0002) and the IODP-China Foundation. No potential conflict of interest was reported by the authors.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
Natural Science Foundation of Guangdong Province2017A030312002
K. C. Wong Education FoundationGJTD-2018-13
South China Sea Deep Project91628301
Chinese Academy of Sciences2019VMA0002
National Natural Science Foundation of China41576070
National Natural Science Foundation of China41625007
NSFUNSPECIFIED
Guangdong Special Support ProgramUNSPECIFIED
International Ocean Discovery Program (IODP)UNSPECIFIED
Subject Keywords:Greenschist-facies mylonite, petrography, microstructure, Continental margin of the northern South China Sea, Cenozoic, IODP367/368
Issue or Number:7-8
Record Number:CaltechAUTHORS:20191017-132811087
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20191017-132811087
Official Citation:Liheng Sun, Zhen Sun, Xiaolong Huang, Yingde Jiang & Joann Miriam Stock (2020) Microstructures documenting Cenozoic extension processes in the northern continental margin of the South China Sea, International Geology Review, 62:7-8, 1094-1107, DOI: 10.1080/00206814.2019.1669079
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:99329
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:22 Oct 2019 22:22
Last Modified:08 Jun 2020 21:26

Repository Staff Only: item control page