File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Geochemistry of Neoproterozoic mafic intrusions in the Panzhihua district (Sichuan Province, SW China): Implications for subduction-related metasomatism in the upper mantle

TitleGeochemistry of Neoproterozoic mafic intrusions in the Panzhihua district (Sichuan Province, SW China): Implications for subduction-related metasomatism in the upper mantle
Authors
KeywordsMafic Intrusions
Metasomatism
Neoproterozoic
Subduction
Sw China
Yangtze Block
Issue Date2007
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/precamres
Citation
Precambrian Research, 2007, v. 152 n. 1-2, p. 27-47 How to Cite?
AbstractMetasomatism above subduction zones is an important process that produces heterogeneous mantle and thus a diversity of igneous rocks. In the Panzhihua district, on the western margin of the Yangtze Block (SW China), two Neoproterozoic mafic intrusions, one olivine gabbro and one hornblende gabbro, have identical ages of 746 ± 10 and 738 ± 23 Ma. Both of the gabbros are tholeiitic in composition and have arc-like geochemical compositions. The hornblende gabbros have K2O concentrations ranging from 0.70 to 1.69 wt.% and show enrichment of Rb, Ba, U, Th and Pb and depletion of Nb,Ta and Ti. They have variable 87Sr/86Sr ratios (0.7045-0.7070) with constant εNd(t) values (-0.12 to -0.93). The olivine gabbros have relatively low K2O (0.19-0.43 wt.%), are depleted in Rb and Th relative to Ba and U, and have obvious negative Nb-Ta and Zr-Hf anomalies on primitive mantle-normalized trace element diagrams. Their εNd(t) values range from -0.64 to -1.73 and initial 87Sr/86Sr ratios from 0.7070 to 0.7075. Both types of gabbro experienced fractional crystallization of clinopyroxene, plagioclase, amphibole and minor Fe-Ti oxide. The parental magmas of the olivine and hornblende gabbros were formed by about 20% partial melting of garnet-spinel lherzolite and spinel lherzolite, respectively. According to trace elemental ratios, the hornblende gabbros were probably derived from a source strongly modified by subducted slab fluids, whereas the olivine gabbros came from a mantle source modified by subducted slab melts. The close association of the olivine gabbros and hornblende gabbros suggests that a steep subduction zone existed along the western margin of the Yangtze Block during Neoproterozoic time. Thus, the giant Neoproterozoic magmatic event in South China was subduction-related. © 2006 Elsevier B.V. All rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/151201
ISSN
2015 Impact Factor: 4.037
2015 SCImago Journal Rankings: 3.214
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorZhao, JHen_US
dc.contributor.authorZhou, MFen_US
dc.date.accessioned2012-06-26T06:18:35Z-
dc.date.available2012-06-26T06:18:35Z-
dc.date.issued2007en_US
dc.identifier.citationPrecambrian Research, 2007, v. 152 n. 1-2, p. 27-47en_US
dc.identifier.issn0301-9268en_US
dc.identifier.urihttp://hdl.handle.net/10722/151201-
dc.description.abstractMetasomatism above subduction zones is an important process that produces heterogeneous mantle and thus a diversity of igneous rocks. In the Panzhihua district, on the western margin of the Yangtze Block (SW China), two Neoproterozoic mafic intrusions, one olivine gabbro and one hornblende gabbro, have identical ages of 746 ± 10 and 738 ± 23 Ma. Both of the gabbros are tholeiitic in composition and have arc-like geochemical compositions. The hornblende gabbros have K2O concentrations ranging from 0.70 to 1.69 wt.% and show enrichment of Rb, Ba, U, Th and Pb and depletion of Nb,Ta and Ti. They have variable 87Sr/86Sr ratios (0.7045-0.7070) with constant εNd(t) values (-0.12 to -0.93). The olivine gabbros have relatively low K2O (0.19-0.43 wt.%), are depleted in Rb and Th relative to Ba and U, and have obvious negative Nb-Ta and Zr-Hf anomalies on primitive mantle-normalized trace element diagrams. Their εNd(t) values range from -0.64 to -1.73 and initial 87Sr/86Sr ratios from 0.7070 to 0.7075. Both types of gabbro experienced fractional crystallization of clinopyroxene, plagioclase, amphibole and minor Fe-Ti oxide. The parental magmas of the olivine and hornblende gabbros were formed by about 20% partial melting of garnet-spinel lherzolite and spinel lherzolite, respectively. According to trace elemental ratios, the hornblende gabbros were probably derived from a source strongly modified by subducted slab fluids, whereas the olivine gabbros came from a mantle source modified by subducted slab melts. The close association of the olivine gabbros and hornblende gabbros suggests that a steep subduction zone existed along the western margin of the Yangtze Block during Neoproterozoic time. Thus, the giant Neoproterozoic magmatic event in South China was subduction-related. © 2006 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/precamresen_US
dc.relation.ispartofPrecambrian Researchen_US
dc.rightsPrecambrian Research. Copyright © Elsevier BV.-
dc.subjectMafic Intrusionsen_US
dc.subjectMetasomatismen_US
dc.subjectNeoproterozoicen_US
dc.subjectSubductionen_US
dc.subjectSw Chinaen_US
dc.subjectYangtze Blocken_US
dc.titleGeochemistry of Neoproterozoic mafic intrusions in the Panzhihua district (Sichuan Province, SW China): Implications for subduction-related metasomatism in the upper mantleen_US
dc.typeArticleen_US
dc.identifier.emailZhou, MF: mfzhou@hkucc.hku.hken_US
dc.identifier.authorityZhou, MF=rp00844en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1016/j.precamres.2006.09.002en_US
dc.identifier.scopuseid_2-s2.0-33751254103en_US
dc.identifier.hkuros128863-
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-33751254103&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume152en_US
dc.identifier.issue1-2en_US
dc.identifier.spage27en_US
dc.identifier.epage47en_US
dc.identifier.isiWOS:000244094100002-
dc.publisher.placeNetherlandsen_US
dc.identifier.scopusauthoridZhao, JH=49061691300en_US
dc.identifier.scopusauthoridZhou, MF=7403506005en_US
dc.customcontrol.immutablesml 130308-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats