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Petrogenesis of the~1.94 Ga Meta-gabbronorites in Liangcheng:Implications for Tectonic Evolution of the Khondalite Belt,North China Craton
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作者 LIAN Guanghui REN Yunwei +2 位作者 SHI Jianrong XU Zhongyuan FENG Fan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第2期418-435,共18页
We investigated the meta-gabbronorites in Liangcheng and used detailed petrography,geochemistry,zircon geochronological and in-situ Hf isotopic studies to clarify their formation and metamorphic ages,petrogenesis,tect... We investigated the meta-gabbronorites in Liangcheng and used detailed petrography,geochemistry,zircon geochronological and in-situ Hf isotopic studies to clarify their formation and metamorphic ages,petrogenesis,tectonic setting and provide constraints on the tectonic evolution of Khondalite Belt(KB).The zircon U-Pb dating results show that the meta-gabbronorites crystallized at~1.94 Ga and were metamorphosed at~1.91–1.89 Ga.They can be subdivided into the low-Mg and high-Mg groups.The low-Mg meta-gabbronorites contain relatively lower MgO and higher SiO2 contents than high-Mg meta-gabbronorites.They are enriched in light rare earth elements and large ion lithophile elements,depleted in high field strength elements,and exhibit positive(high-Mg meta-gabbronorites)and negative(low-Mg metagabbronorites)Sr and Eu anomalies.The zircon in-situεHf(t)of meta-gabbronorites is 0.07–4.12,with Hf model ages(TDM)of 2169–2400 Ma.The meta-gabbronorites in Liangcheng originated from the asthenospheric mantle and experienced fractional crystallization of olivine,orthopyroxene,clinopyroxene,and plagioclase.They were contaminated by the crustal rocks(mainly khondalite series)during ascent,especially for low-Mg gabbronorites.The ridge subduction is the most plausible tectonic setting for meta-gabbronorites,indicating the eastern segment of KB was in a ridge subduction setting at~1.94 Ga following an orogenic thickening event during a prolonged orogenic process. 展开更多
关键词 meta-gabbronorites PALEOPROTEROZOIC Liangcheng Khondalite belt North China Craton
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Characterization of partial melting events in garnet-cordierite gneiss from the Kerala Khondalite Belt,India 被引量:1
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作者 Nilanjana Sorcar Kumar Batuk Joshi +2 位作者 Elson POliveira JKTomson VNandakumar 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第2期597-611,共15页
Phase equilibria modelling coupled with U–Pb zircon and monazite ages of garnet–cordierite gneiss from Vallikodu Kottayam in the Kerala Khondalite Belt,southern India are presented here.The results suggest that the ... Phase equilibria modelling coupled with U–Pb zircon and monazite ages of garnet–cordierite gneiss from Vallikodu Kottayam in the Kerala Khondalite Belt,southern India are presented here.The results suggest that the area attained peak P–T conditions of^900C at 7.5–8 kbar,followed by decompression to 3.5–5 kbar and cooling to 450–480C,preserving signatures of the partial melting event in the field of high to ultra-high temperature metamorphism.Melt reintegration models suggest that up to 35%granitic melt could have been produced during metamorphism at^950C.The U–Pb age data from zircons(~1.0–~0.7 Ga)and chemical ages from monazites(~540 Ma and^941 Ma)reflect a complex tectonometamorphic evolution of the terrain.The^941 Ma age reported from these monazites indicate a Tonian ultra-high temperature event,linked to juvenile magmatism/deformation episodes reported from the Southern Granulite Terrane and associated fragments in Rodinia,which were subsequently overprinted by the Cambrian(~540 Ma)tectonothermal episode. 展开更多
关键词 Kerala khondalite belt(KKB) Garnet-cordierite gneiss Partial melting PSEUDOSECTION Monazite-zircon geochronology
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Petrological evidence for isobaric cooling of ultrahightemperature pelitic granulites from the Khondalite Belt,North China Craton 被引量:6
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作者 Longlong Gou Chengli Zhang Quan Wang 《Science Bulletin》 SCIE EI CAS CSCD 2015年第17期1535-1542,共8页
The ultrahigh-temperature(UHT) pelitic granulites from the Khondalite Belt, North China Craton(NCC), contain ilmenite in the matrix, which has been partially replaced by rutile. Based on this observation and the growt... The ultrahigh-temperature(UHT) pelitic granulites from the Khondalite Belt, North China Craton(NCC), contain ilmenite in the matrix, which has been partially replaced by rutile. Based on this observation and the growth of biotite by garnet-consuming reaction, the UHT rocks are inferred to have recorded three metamorphic stages: the peak metamorphic stage(M1) and two retrograde metamorphic stages(M2 and M3). The M1 stage is represented by the assemblage of perthite+sillimanite+ ilmenite in the matrix, and quartz inclusions bearing(in the cores) garnet porphyroblasts. The M2 stage is defined by rutile-replacing ilmenite and growth of garnet mantles and rims containing acicular sillimanite inclusions, with the garnet+ perthite+ sillimanite+rutile+ ilmenite+ quartz assemblage. The M3 stage is recorded by the growth of biotite in the matrix, with the garnet+ biotite+ perthite+ sillimanite+rutile+ilmenite+quartz assemblage. Based on phase equilibrium modeling, an isobaric cooling path is reconstructed, which is consistent with the idea that mantle-derived magma provided the heat for the UHT metamorphism in the Khondalite Belt, NCC. 展开更多
关键词 P-T pseudosection Isobaric cooling UHT metamorphism Khondalite belt North China Craton
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