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Article: Emeishan large igneous province, SW China

TitleEmeishan large igneous province, SW China
Authors
KeywordsEmeishan
Flood Basalts
Guadalupian
Lip
Mantle Plume
Permian
Issue Date2005
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/lithos
Citation
Lithos, 2005, v. 79 n. 3-4 SPEC. ISS., p. 475-489 How to Cite?
AbstractIn recent years, there have been major advances in our understanding of the Emeishan large igneous province (LIP) of SW China following publication of a number of LIP-focused investigations of the terrain and associated rocks. This paper reviews the current state of knowledge. The volcanic and upper-intrusive portion of the province is relatively small (∼0.3 × 10 6 km 3), even when offset fragments, eroded sections and buried portions are included in the volume calculation. The most reliable radiometric age dates (zircon U-Pb SHRIMP from an associated layered intrusive body several kilometers in area) indicate generation at ∼259 Ma, consistent with the end-Guadalupian (end Middle Permian) stratigraphic age. In addition, several Ar-Ar dating studies have been carried out, mainly on the volcanic rocks, with a number of reported dates ∼253-251 Ma (Late Permian), but a consensus is emerging that these ages are problematic because they are in conflict with the stratigraphic data (possibly due to a monitor standard miscalibration). The Ar-Ar investigations have also yielded a large number of secondary ages, which are clustered at ∼175, ∼142, ∼98 and ∼42 Ma, and these are inferred to record sub-regional tectonic events that affected the western Yangtze Block as East Asia was assembled and later deformed by India's collision-indentation into Asia. Magnetostratigraphic data and field observations suggest that the bulk of the volcanic sequence formed within 1-2 my. The geochemistry of the volcanic rocks and bio-lithostratigraphic studies of the underlying Maokou Formation suggests a mantle plume generated the province. The basalts can be classified into low and high Ti groups with different parental magmas. The low Ti basalts are confined to the western part of the province and are overlain by the high Ti basalts. The low Ti magmas formed at shallow mantle depths in the spinel-garnet field transition zone (60-80 km), whereas the high Ti magmas formed by low degrees of partial melting within the deeper garnet stability field. This observation suggests a deepening of the melting column as the lithosphere thickened due to under-plating and a transition from peak basalt generation to the waning stage. Outstanding issues, which might focus future studies, are also outlined. © 2004 Elsevier B.V. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/151128
ISSN
2014 Impact Factor: 4.482
2014 SCImago Journal Rankings: 2.461
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorAli, JRen_US
dc.contributor.authorThompson, GMen_US
dc.contributor.authorZhou, MFen_US
dc.contributor.authorSong, Xen_US
dc.date.accessioned2012-06-26T06:17:26Z-
dc.date.available2012-06-26T06:17:26Z-
dc.date.issued2005en_US
dc.identifier.citationLithos, 2005, v. 79 n. 3-4 SPEC. ISS., p. 475-489en_US
dc.identifier.issn0024-4937en_US
dc.identifier.urihttp://hdl.handle.net/10722/151128-
dc.description.abstractIn recent years, there have been major advances in our understanding of the Emeishan large igneous province (LIP) of SW China following publication of a number of LIP-focused investigations of the terrain and associated rocks. This paper reviews the current state of knowledge. The volcanic and upper-intrusive portion of the province is relatively small (∼0.3 × 10 6 km 3), even when offset fragments, eroded sections and buried portions are included in the volume calculation. The most reliable radiometric age dates (zircon U-Pb SHRIMP from an associated layered intrusive body several kilometers in area) indicate generation at ∼259 Ma, consistent with the end-Guadalupian (end Middle Permian) stratigraphic age. In addition, several Ar-Ar dating studies have been carried out, mainly on the volcanic rocks, with a number of reported dates ∼253-251 Ma (Late Permian), but a consensus is emerging that these ages are problematic because they are in conflict with the stratigraphic data (possibly due to a monitor standard miscalibration). The Ar-Ar investigations have also yielded a large number of secondary ages, which are clustered at ∼175, ∼142, ∼98 and ∼42 Ma, and these are inferred to record sub-regional tectonic events that affected the western Yangtze Block as East Asia was assembled and later deformed by India's collision-indentation into Asia. Magnetostratigraphic data and field observations suggest that the bulk of the volcanic sequence formed within 1-2 my. The geochemistry of the volcanic rocks and bio-lithostratigraphic studies of the underlying Maokou Formation suggests a mantle plume generated the province. The basalts can be classified into low and high Ti groups with different parental magmas. The low Ti basalts are confined to the western part of the province and are overlain by the high Ti basalts. The low Ti magmas formed at shallow mantle depths in the spinel-garnet field transition zone (60-80 km), whereas the high Ti magmas formed by low degrees of partial melting within the deeper garnet stability field. This observation suggests a deepening of the melting column as the lithosphere thickened due to under-plating and a transition from peak basalt generation to the waning stage. Outstanding issues, which might focus future studies, are also outlined. © 2004 Elsevier B.V. All rights reserved.en_US
dc.languageengen_US
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/lithosen_US
dc.relation.ispartofLithosen_US
dc.rightsLithos. Copyright © Elsevier BV.-
dc.subjectEmeishanen_US
dc.subjectFlood Basaltsen_US
dc.subjectGuadalupianen_US
dc.subjectLipen_US
dc.subjectMantle Plumeen_US
dc.subjectPermianen_US
dc.titleEmeishan large igneous province, SW Chinaen_US
dc.typeArticleen_US
dc.identifier.emailAli, JR: jrali@hku.hken_US
dc.identifier.emailZhou, MF: mfzhou@hkucc.hku.hken_US
dc.identifier.authorityAli, JR=rp00659en_US
dc.identifier.authorityZhou, MF=rp00844en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/j.lithos.2004.09.013en_US
dc.identifier.scopuseid_2-s2.0-11244329133en_US
dc.identifier.hkuros108404-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-11244329133&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume79en_US
dc.identifier.issue3-4 SPEC. ISS.en_US
dc.identifier.spage475en_US
dc.identifier.epage489en_US
dc.identifier.isiWOS:000226613200012-
dc.publisher.placeNetherlandsen_US
dc.identifier.scopusauthoridAli, JR=7102266465en_US
dc.identifier.scopusauthoridThompson, GM=7403078084en_US
dc.identifier.scopusauthoridZhou, MF=7403506005en_US
dc.identifier.scopusauthoridSong, X=7402269092en_US

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