Article: Emeishan Basalt Ar-Ar overprint ages define several tectonic events that affected the western Yangtze platform in the Mesozoic and Cenozoic

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TitleEmeishan Basalt Ar-Ar overprint ages define several tectonic events that affected the western Yangtze platform in the Mesozoic and Cenozoic
AuthorsAli, JR2
Lo, CH1
Thompson, GM2
Song, X2 3
KeywordsChina Amalgamation
Collision
Longmen Shan
Tectonic Resetting
Issue Date2004
PublisherPergamon. The Journal's web site is located at http://www.elsevier.com/locate/jseaes
CitationJournal Of Asian Earth Sciences, 2004, v. 23 n. 2, p. 163-178 [How to Cite?]
DOI: http://dx.doi.org/10.1016/S1367-9120(03)00072-5
AbstractAr-Ar whole-rock dating was carried out as part of a detailed stratigraphical investigation of the Emeishan Basalt large igneous province (LIP) in the stratotype area, Sichuan, China. Thirteen (from twenty-one) specimens from three sections yielded reliable reversed isochron and plateau ages (maximum 1σ errors of ≤2.1 and 1.6 m.y., respectively), and form two clusters centered on the Late Jurassic-Early Cretaceous and Early-Late Cretaceous, with a tail spanning 82-40 Ma. However, all are appreciably younger than the magnetobiostratigraphically-constrained late Middle Permian (255-260 Ma) age of the basalts, reflecting varying degrees of thermal resetting during the Mesozoic and Cenozoic. Recently, Middle Jurassic-Early Cretaceous ages reported from elsewhere in the LIP have been used to infer a single 40 m.y.-long tectonic episode that affected the western Yangtze Platform. Developing this idea, the new information have been combined with data we hold for other parts of the terrain, and results from three Emeishan LIP Ar-Ar dating studies published during 2002, to give 32 reliable age dates. Three 10-12 m.y. events appear to be recorded in different parts of the province: Middle Jurassic, Late Jurassic-Early Cretaceous and Early-Late Cretaceous, with a fourth shorter middle Eocene episode (the 40 m.y. Mesozoic episode appears to be a sampling artifact). Following a review of the regional deformation/tectonic features, it is argued that activity related to various phases of deformation in the Longmen Shan Thrust Belt is the most likely cause of resetting. The final suturing of the North and South China blocks may have also been responsible for the Middle Jurassic event. However, the Oligocene-present indentation of India into Asia appears not to have had an impact, possibly due to the large-scale related strike-slip faults that have effectively shielded the LIP/Sichuan Basin. © 2003 Elsevier Ltd. All rights reserved.
ISSN1367-9120
2011 Impact Factor: 2.152
2011 SCImago Journal Rankings: 0.062
DOIhttp://dx.doi.org/10.1016/S1367-9120(03)00072-5
ReferencesReferences in Scopus
DC Field
Value
dc.contributor.authorAli, JR
dc.contributor.authorLo, CH
dc.contributor.authorThompson, GM
dc.contributor.authorSong, X
dc.date.accessioned2012-06-26T06:17:43Z
dc.date.available2012-06-26T06:17:43Z
dc.date.issued2004
dc.description.abstractAr-Ar whole-rock dating was carried out as part of a detailed stratigraphical investigation of the Emeishan Basalt large igneous province (LIP) in the stratotype area, Sichuan, China. Thirteen (from twenty-one) specimens from three sections yielded reliable reversed isochron and plateau ages (maximum 1σ errors of ≤2.1 and 1.6 m.y., respectively), and form two clusters centered on the Late Jurassic-Early Cretaceous and Early-Late Cretaceous, with a tail spanning 82-40 Ma. However, all are appreciably younger than the magnetobiostratigraphically-constrained late Middle Permian (255-260 Ma) age of the basalts, reflecting varying degrees of thermal resetting during the Mesozoic and Cenozoic. Recently, Middle Jurassic-Early Cretaceous ages reported from elsewhere in the LIP have been used to infer a single 40 m.y.-long tectonic episode that affected the western Yangtze Platform. Developing this idea, the new information have been combined with data we hold for other parts of the terrain, and results from three Emeishan LIP Ar-Ar dating studies published during 2002, to give 32 reliable age dates. Three 10-12 m.y. events appear to be recorded in different parts of the province: Middle Jurassic, Late Jurassic-Early Cretaceous and Early-Late Cretaceous, with a fourth shorter middle Eocene episode (the 40 m.y. Mesozoic episode appears to be a sampling artifact). Following a review of the regional deformation/tectonic features, it is argued that activity related to various phases of deformation in the Longmen Shan Thrust Belt is the most likely cause of resetting. The final suturing of the North and South China blocks may have also been responsible for the Middle Jurassic event. However, the Oligocene-present indentation of India into Asia appears not to have had an impact, possibly due to the large-scale related strike-slip faults that have effectively shielded the LIP/Sichuan Basin. © 2003 Elsevier Ltd. All rights reserved.
dc.description.natureLink_to_subscribed_fulltext
dc.identifier.citationJournal Of Asian Earth Sciences, 2004, v. 23 n. 2, p. 163-178 [How to Cite?]
DOI: http://dx.doi.org/10.1016/S1367-9120(03)00072-5
dc.identifier.doihttp://dx.doi.org/10.1016/S1367-9120(03)00072-5
dc.identifier.epage178
dc.identifier.hkuros90882
dc.identifier.isiWOS:000220961200002
dc.identifier.issn1367-9120
2011 Impact Factor: 2.152
2011 SCImago Journal Rankings: 0.062
dc.identifier.issue2
dc.identifier.scopuseid_2-s2.0-1942473112
dc.identifier.spage163
dc.identifier.urihttp://hdl.handle.net/10722/151151
dc.identifier.volume23
dc.languageeng
dc.publisherPergamon. The Journal's web site is located at http://www.elsevier.com/locate/jseaes
dc.publisher.placeUnited Kingdom
dc.relation.ispartofJournal of Asian Earth Sciences
dc.relation.referencesReferences in Scopus
dc.subjectChina Amalgamation
dc.subjectCollision
dc.subjectLongmen Shan
dc.subjectTectonic Resetting
dc.titleEmeishan Basalt Ar-Ar overprint ages define several tectonic events that affected the western Yangtze platform in the Mesozoic and Cenozoic
dc.typeArticle
Author Affiliations
  1. National Taiwan University
  2. The University of Hong Kong
  3. Chengdu University of Technology