File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Zircon U–Pb geochronology and geochemistry of two types of Paleoproterozoic granitoids from the southeastern margin of the North China Craton: Constraints on petrogenesis and tectonic significance

TitleZircon U–Pb geochronology and geochemistry of two types of Paleoproterozoic granitoids from the southeastern margin of the North China Craton: Constraints on petrogenesis and tectonic significance
Authors
KeywordsA-type granite
Anataxis
Jiao-Liao-Ji Belt
North China Craton
Paleoproterozoic
Issue Date2017
PublisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/precamres
Citation
Precambrian Research, 2017, v. 303, p. 268-290 How to Cite?
AbstractTwo types of Paleoproterozoic granitoids, i.e., K-feldspar/albite granites and granitic gneisses, were recognized from the Wuhe Complex of the Precambrian basement and neighboring areas in the southeastern margin of the North China Craton (NCC). They share the identical 207Pb/206Pb ages of 2096 ± 9 Ma and 2096 ± 8 Ma defined by zircon SHRIMP U–Pb dating. These granitic rocks are commonly enriched in HREE, Zr, Nb, Ga and Y, and depleted in V, Cr and Ni, most of which have high TFeO/MgO ratios and Zr-saturation temperatures over 850 °C, suggestive of an affinity with A-type granite. In addition, both have consistent whole-rock εNd(t) values (−3.0 to −0.9) and zircon Hf isotopic compositions (εHf (t) = −3.3 to +1.9). The latter are similar with ones of the Neoarchean TTG gneisses in the Eastern Block of the NCC. Thus these ∼2.1 Ga granitoids in the region were most likely derived from the partial melting of ∼2.5 Ga TTG gneisses with minor involvement of coeval mafic crustal materials. The zircon grains from the granitic gneisses can be categorized into core, mantle and rim domains with distinct CL images and trace-element characteristics. The grey mantles exhibit steep REE patterns, low LREE, Th, Pb contents and remarkably low Th/U ratios (<0.1), and define mean U/Pb ages of ∼1.85 Ga. The dark rims display relatively higher LREE, U, Th, Pb contents and Th/U values (0.1–0.3) with slightly younger ages of 1.81–1.83 Ga than mantles. Accordingly, the zircon mantles and rims are interpreted as metamorphic zircons formed during granulite facies metamorphism and anatectic zircons crystallized from limited melts, respectively. The comparable 2.1 Ga magmatism, ∼1.85 Ga high grade metamorphism and subsequent anataxis between the granitic rocks in this study and the Jiao-Liao-Ji Belt (JLJB) suggest that the Wuhe Complex and the JLJB share the same tectonic evolutional processes. These two types of granitoids both formed at an extensional background at ∼2.1 Ga, perhaps in a subduction-related rifting environment, subsequently suffered from granulite-facies metamorphism and selected partial melting during the Paleoproterozoic collisional orogeny.
Persistent Identifierhttp://hdl.handle.net/10722/263353
ISSN
2017 Impact Factor: 3.907
2015 SCImago Journal Rankings: 3.214
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorWang, CC-
dc.contributor.authorLiu, YC-
dc.contributor.authorZhang, P-
dc.contributor.authorZhao, G-
dc.contributor.authorWang, A-
dc.contributor.authorSong, B-
dc.date.accessioned2018-10-22T07:37:35Z-
dc.date.available2018-10-22T07:37:35Z-
dc.date.issued2017-
dc.identifier.citationPrecambrian Research, 2017, v. 303, p. 268-290-
dc.identifier.issn0301-9268-
dc.identifier.urihttp://hdl.handle.net/10722/263353-
dc.description.abstractTwo types of Paleoproterozoic granitoids, i.e., K-feldspar/albite granites and granitic gneisses, were recognized from the Wuhe Complex of the Precambrian basement and neighboring areas in the southeastern margin of the North China Craton (NCC). They share the identical 207Pb/206Pb ages of 2096 ± 9 Ma and 2096 ± 8 Ma defined by zircon SHRIMP U–Pb dating. These granitic rocks are commonly enriched in HREE, Zr, Nb, Ga and Y, and depleted in V, Cr and Ni, most of which have high TFeO/MgO ratios and Zr-saturation temperatures over 850 °C, suggestive of an affinity with A-type granite. In addition, both have consistent whole-rock εNd(t) values (−3.0 to −0.9) and zircon Hf isotopic compositions (εHf (t) = −3.3 to +1.9). The latter are similar with ones of the Neoarchean TTG gneisses in the Eastern Block of the NCC. Thus these ∼2.1 Ga granitoids in the region were most likely derived from the partial melting of ∼2.5 Ga TTG gneisses with minor involvement of coeval mafic crustal materials. The zircon grains from the granitic gneisses can be categorized into core, mantle and rim domains with distinct CL images and trace-element characteristics. The grey mantles exhibit steep REE patterns, low LREE, Th, Pb contents and remarkably low Th/U ratios (<0.1), and define mean U/Pb ages of ∼1.85 Ga. The dark rims display relatively higher LREE, U, Th, Pb contents and Th/U values (0.1–0.3) with slightly younger ages of 1.81–1.83 Ga than mantles. Accordingly, the zircon mantles and rims are interpreted as metamorphic zircons formed during granulite facies metamorphism and anatectic zircons crystallized from limited melts, respectively. The comparable 2.1 Ga magmatism, ∼1.85 Ga high grade metamorphism and subsequent anataxis between the granitic rocks in this study and the Jiao-Liao-Ji Belt (JLJB) suggest that the Wuhe Complex and the JLJB share the same tectonic evolutional processes. These two types of granitoids both formed at an extensional background at ∼2.1 Ga, perhaps in a subduction-related rifting environment, subsequently suffered from granulite-facies metamorphism and selected partial melting during the Paleoproterozoic collisional orogeny.-
dc.languageeng-
dc.publisherElsevier BV. The Journal's web site is located at http://www.elsevier.com/locate/precamres-
dc.relation.ispartofPrecambrian Research-
dc.subjectA-type granite-
dc.subjectAnataxis-
dc.subjectJiao-Liao-Ji Belt-
dc.subjectNorth China Craton-
dc.subjectPaleoproterozoic-
dc.titleZircon U–Pb geochronology and geochemistry of two types of Paleoproterozoic granitoids from the southeastern margin of the North China Craton: Constraints on petrogenesis and tectonic significance-
dc.typeArticle-
dc.identifier.emailZhao, G: gzhao@hku.hk-
dc.identifier.authorityZhao, G=rp00842-
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1016/j.precamres.2017.04.015-
dc.identifier.scopuseid_2-s2.0-85017429454-
dc.identifier.hkuros294407-
dc.identifier.volume303-
dc.identifier.spage268-
dc.identifier.epage290-
dc.identifier.isiWOS:000423004300015-
dc.publisher.placeNetherlands-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats