File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Association of Neoproterozoic A- and I-type granites in South China: Implications for generation of A-type granites in a subduction-related environment

TitleAssociation of Neoproterozoic A- and I-type granites in South China: Implications for generation of A-type granites in a subduction-related environment
Authors
KeywordsA-type granite
Charnockite
I-type granite
Neoproterozoic
Yangtze Block
Issue Date2008
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/chemgeo
Citation
Chemical Geology, 2008, v. 257 n. 1-2, p. 1-15 How to Cite?
AbstractNeoproterozoic magmatism in the Yangtze Block of South China produced voluminous S- and I-type granites, and sparse A-type granites. The Daxiangling A-type granitic pluton is spatially associated with the Shimian I-type pluton at the western margin of the Yangtze Block. Both plutons have similar SHRIMP zircon U-Pb ages of ∼ 800 Ma and are slightly younger than the tonalite-trondhjemite-granodiorite (TTG) gneisses in the area. The Shimian pluton is composed of granite and monzogranite with high SiO2 (69.3-76.6 wt.%), Na2O (2.79-3.80 wt.%) and K2O (3.94-5.87 wt.%), and low Fe2O3 (0.96-3.06 wt.%) and MgO (0.12-0.50 wt.%). The Daxiangling pluton consists of alkali-feldspar granites with higher SiO2 (76.3-79.3 wt.%) and lower Al2O3 (10.6-11.9 wt.%) and CaO (0.21-0.55 wt.%) than the Shimian granites. Both plutons are slightly peraluminous (A/CNK = 1.00-1.12) and belong to the high-K, calc-alkaline series. The Daxiangling alkali-feldspar granites have much higher Zr, Hf, Ga and HREE, and lower Sr than the Shimian granites. On the chondrite-normalized REE diagram, both plutons are enriched in LREE, but the rocks of the Daxiangling pluton show relatively flat patterns because of their higher HREE contents. Their primitive-mantle normalized spidergrams display negative Eu, Nb, Ta, Sr, P and Ti anomalies. Both plutons have nearly identical whole-rock Nd and zircon Hf isotopic compositions (εNd(t) = + 1 and εHf(t) = + 5 to + 9), similar to the TTG gneisses. We suggest that the I-type granites of the Shimian pluton were produced by dehydration melting of the TTG rocks as a result of underplating of mantle-derived mafic magmas. The rocks above the I-type magma source may have been converted to charnockites by heating and dehydration. With increasing temperatures, the charnockites underwent partial melting at temperatures > 900 °C to produce A-type magmas. Both the A- and I-type granites formed at an extensional active continental margin, perhaps in a back-arc environment. A-type granites with mantle-like isotopic signatures may be reworked or recycled from juvenile crustal rocks. The association of A- and I-type granites suggests that aluminous A-type granite is most probably derived from a charnockite source heated by large-scale magmatic underplating, rather than a tonalite source. Crown Copyright © 2008.
Persistent Identifierhttp://hdl.handle.net/10722/58674
ISSN
2015 Impact Factor: 3.482
2015 SCImago Journal Rankings: 2.346
ISI Accession Number ID
Funding AgencyGrant Number
CRCG University of Hong Kong
Funding Information:

We thank Xiaodong Deng for assistance in the field, Xiao Fu and Jianfeng Gao for major and trace element analysis, respectively, Allen Kennedy and Xiaoping Xia for Zircon U-Pb dating, and Yueheng Yang for zircon Lu-Hf analysis. We acknowledge Prof. P. Robinson to read an early draft of this paper. Support by a Chinese 973 project matching fund and a CRCG grant from the University of Hong Kong is thanked. Two anonymous reviewers are greatly appreciated for their helpful and constructive reviews.

References

 

DC FieldValueLanguage
dc.contributor.authorZhao, XFen_HK
dc.contributor.authorZhou, MFen_HK
dc.contributor.authorLi, JWen_HK
dc.contributor.authorWu, FYen_HK
dc.date.accessioned2010-05-31T03:34:49Z-
dc.date.available2010-05-31T03:34:49Z-
dc.date.issued2008en_HK
dc.identifier.citationChemical Geology, 2008, v. 257 n. 1-2, p. 1-15en_HK
dc.identifier.issn0009-2541en_HK
dc.identifier.urihttp://hdl.handle.net/10722/58674-
dc.description.abstractNeoproterozoic magmatism in the Yangtze Block of South China produced voluminous S- and I-type granites, and sparse A-type granites. The Daxiangling A-type granitic pluton is spatially associated with the Shimian I-type pluton at the western margin of the Yangtze Block. Both plutons have similar SHRIMP zircon U-Pb ages of ∼ 800 Ma and are slightly younger than the tonalite-trondhjemite-granodiorite (TTG) gneisses in the area. The Shimian pluton is composed of granite and monzogranite with high SiO2 (69.3-76.6 wt.%), Na2O (2.79-3.80 wt.%) and K2O (3.94-5.87 wt.%), and low Fe2O3 (0.96-3.06 wt.%) and MgO (0.12-0.50 wt.%). The Daxiangling pluton consists of alkali-feldspar granites with higher SiO2 (76.3-79.3 wt.%) and lower Al2O3 (10.6-11.9 wt.%) and CaO (0.21-0.55 wt.%) than the Shimian granites. Both plutons are slightly peraluminous (A/CNK = 1.00-1.12) and belong to the high-K, calc-alkaline series. The Daxiangling alkali-feldspar granites have much higher Zr, Hf, Ga and HREE, and lower Sr than the Shimian granites. On the chondrite-normalized REE diagram, both plutons are enriched in LREE, but the rocks of the Daxiangling pluton show relatively flat patterns because of their higher HREE contents. Their primitive-mantle normalized spidergrams display negative Eu, Nb, Ta, Sr, P and Ti anomalies. Both plutons have nearly identical whole-rock Nd and zircon Hf isotopic compositions (εNd(t) = + 1 and εHf(t) = + 5 to + 9), similar to the TTG gneisses. We suggest that the I-type granites of the Shimian pluton were produced by dehydration melting of the TTG rocks as a result of underplating of mantle-derived mafic magmas. The rocks above the I-type magma source may have been converted to charnockites by heating and dehydration. With increasing temperatures, the charnockites underwent partial melting at temperatures > 900 °C to produce A-type magmas. Both the A- and I-type granites formed at an extensional active continental margin, perhaps in a back-arc environment. A-type granites with mantle-like isotopic signatures may be reworked or recycled from juvenile crustal rocks. The association of A- and I-type granites suggests that aluminous A-type granite is most probably derived from a charnockite source heated by large-scale magmatic underplating, rather than a tonalite source. Crown Copyright © 2008.en_HK
dc.languageengen_HK
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/chemgeoen_HK
dc.relation.ispartofChemical Geologyen_HK
dc.subjectA-type graniteen_HK
dc.subjectCharnockiteen_HK
dc.subjectI-type graniteen_HK
dc.subjectNeoproterozoicen_HK
dc.subjectYangtze Blocken_HK
dc.titleAssociation of Neoproterozoic A- and I-type granites in South China: Implications for generation of A-type granites in a subduction-related environmenten_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0009-2541&volume=257&issue=1-2&spage=1&epage=15&date=2008&atitle=Association+of+Neoproterozoic+A-+and+I-type+granites+in+South+China:+implications+for+generation+of+A-type+granites+in+a+subduction-related+environmenten_HK
dc.identifier.emailZhou, MF:mfzhou@hkucc.hku.hken_HK
dc.identifier.authorityZhou, MF=rp00844en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1016/j.chemgeo.2008.07.018en_HK
dc.identifier.scopuseid_2-s2.0-54849428499en_HK
dc.identifier.hkuros167316en_HK
dc.identifier.hkuros192930en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-54849428499&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume257en_HK
dc.identifier.issue1-2en_HK
dc.identifier.spage1en_HK
dc.identifier.epage15en_HK
dc.identifier.isiWOS:000261564200001-
dc.publisher.placeNetherlandsen_HK
dc.identifier.scopusauthoridZhao, XF=49061648300en_HK
dc.identifier.scopusauthoridZhou, MF=7403506005en_HK
dc.identifier.scopusauthoridLi, JW=36067183300en_HK
dc.identifier.scopusauthoridWu, FY=40561925600en_HK

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats