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Acta Geochimica 2023年第5期42卷 879-894页

作者： Zhaode Xia Haibo Ding Yanjiao Ru School of Earth Science and Resources Chang’an UniversityXi’an 710054ShaanxiChina The Third Geological Branch Xinjiang Geological and Mineral BureauKuerleXinjiang 841000China Geophysical and Geochemical Exploration Corporation Bureau of Geological Exploration for Nonferrous Metals in Northwest ChinaXi’an 710068ShaanxiChina

The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Dunde mining area in order to constrain the tectonicmagmatic activities and metallogenesis of this *** in the southwest of Dunde mining area are mainly syenogranites intruded into volcanics of the Dahalajunshan Formation in the Early Carboniferous,and they are far from the area where ore bodies and mineralized altered rocks are widely ***-ICP-MS U–Pb zircon dating indicates that Dunde syenogranite was at 306.8±1.0 Ma,which could constrain the upper limit of metallogenic age for this *** Dunde granites are high SiO_(2)(73.41–80.07 wt%),high differentiation index(D.I.=89.7–95.0),weakly peraluminous to metaluminous(A/CNK=0.94–1.08),and they are enriched in LILE and LREE and depleted in Eu,Ba,Sr and P_(2)O_(5),indicating that they belong to highly fractionated Ⅰ-type *** on εHf values(+9.2 to+10.5)for zircon and high εNd(-t)values(+4.7 to+5.8)for whole-rock,and the two-stage model ages for 601–735 Ma,suggest that the magma source could be the juvenile lower *** with regional geological setting,the 306.8 Ma Dunde granites are formed in post-collision extensional tectonic setting.

关键词： Granite Geochemistry magma source Tectonic setting Dunde deposit Western Tianshan

Geochronology,Geochemistry,and Sr-Nd-Hf Isotopes of the Diorite Porphyrites from the Weining Beishan Area,Ningxia Hui Autonomous Region:Constraints on Their source and Tectonic Implications

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Journal of Earth Science 2024年第2期35卷 462-475页

作者： Anlu Liu Lianfu Hai Jinke Liu Xiaojun Zhang Haifeng Li Fengshun Zhao Guoliang Zhao Jinhe Bai Yifu Museum China University of GeosciencesWuhan430074China School of Earth Resources China University of GeosciencesWuhan430074China Mineral Geological Survey Institute of Ningxia Hui Autonomous Region Yinchuan750021China National Demonstration Center for Experimental Mineral Exploration Education China University of GeosciencesWuhan430074China Coal Geological Survey Institute of Ningxia Hui Autonomous Region Yinchuan750021China Zhuhai Engineering Investigation Institute of Guangdong Province Zhuhai519000China

The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic ***,the tectonic evolution of this area remains unclear due to the lack of magmatic *** paper conducted researches on geochronology,geochemistry,and Sr-Nd-Hf isotopes of the diorite porphyrites exposed in the Weining Beishan *** zircon U-Pb dating yields two ages of 145.0±1.1 and 146.2±1.5 Ma,and the whole-rock geochemical data indicate that the diorite porphyrites are metaluminous to weakly peraluminous and high-K calc-alkaline *** characteristics of highly initial^(87)Sr/^(86)Sr ratios(0.70816 to 0.71047),negativeε_(Nd)(t)(−8.9 to−8.4),and negativeε_(Hf)(t)(−13.8 to−21.2)indicate that the diorite porphyrites originated from partial melting of the middle-lower ancient crust related to the North China *** with the regional geology,we suggested that partial melting was triggered by a tectonic activity of deep faults cutting through the crust under the regional stress transformation from compressing to extension during the Late Jurassic–Early Cretaceous,which is probably related to the westward subduction of the Paleo-Pacific Plate.

关键词： zircon U-Pb dating Sr-Nd-Hf isotopes magma source diorite porphyrite Weining Beishan area Ningxia Hui Autonomous Region geochronology geochemistry

Late Cryogenian-Ediacaran magmatism in southern Borborema Province,NE Brazil:Ages,sources,petrogenesis,and tectonic setting

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Geoscience Frontiers 2023年第6期14卷 70-101页

作者： Fábio Santos Pereira Herbet Conceição Maria de Lourdes Silva Rosa Moacyr Moura Marinho Colombo Celso Gaeta Tassinari João Marinho Milhomem Neto Jean-Michel Lafon Programa de Pós-Graduação em Geologia e Geoquímica(PPGG) Instituto de GeociênciasUniversidade Federal do Pará(UFPA)66075-110 BelémParáBrazil Programa de Pós-Graduação em Geociências e Análise de Bacias(PGAB) Universidade Federal de Sergipe(UFS)49100-000 São CristóvãoSergipeBrazil Instituto de Geociências Universidade Federal da Bahia(UFBA)40170-290 SalvadorBahiaBrazil Instituto de Geociências Universidade de São Paulo(USP)05508-900 São PauloBrazil Laboratório de Geologia Isotópica(Pará-Iso) IG-UFPA66075-110 BelémParáBrazil

The Sergipano Orogenic System(SOS)in southern Borborema Province(NE Brazil)hosts voluminous Neoproterozoic plutonism related to the Brasiliano/Pan-African *** paper presents comprehensive whole-rock geochemical data,titanite U-Pb ages,and the first combined zircon U-Pb and Lu-Hf isotope results for plutonic rocks from the MacururéDomain to constrain their sources,petrogenesis,and tectonic *** magmatic episodes are recognized and record the evolutionary stages of the orogen.(i)Early-collisional magmatism(643–628 Ma)comprises gabbros and diorites with minor tonalites characterized by well-developed tectonic foliation and evidence of solid-state *** rocks are magnesian,high-K calc-alkaline,LILE-and LREE-enriched and provide subchondriticε_(Hf)(t)values(6.5 to4.7)and Orosirian Hf-T^(C)_(DM)model ages(1.83–1.94 Ga).Such features indicate derivation from a lithospheric mantle source metasomatized by incorporating crustal components through subduction processes prior to magma generation,possibly related to the Rhyacian Orogeny(2.20–1.96 Ga).Extensive mixing/mingling between basaltic and crust-derived magmas took place at lower crustal depths,producing coeval hybrid diorites and quartz-diorites.(ii)Syn-collisional magmatism(630–624 Ma)encompasses biotite-and muscovite-bearing granodiorites and monzogranites,preserving their structures parallel to the schistosity of the country *** rocks are leucocratic,weakly metaluminous to peraluminous,and contain abundant surmicaceous *** features and geochemical composition suggest an origin related to the partial melting of graywacke protoliths with a subordinate igneous component.(iii)Late-collisional magmatism(625–600 Ma)includes undeformed and isotropic monzonites and granodiorites,which truncate the regional *** rocks are consistently metaluminous and magnesian,showing affinities with the high-K calc-alkaline to shoshonite *** element modeling with su

关键词： Brasiliano/Pan-African Orogeny Western Gondwana Zircon and titanite U-Pb dating Hf isotope data magma source

Chronology and Geochemistry of Mesozoic Volcanic Rocks in the Linjiang Area,Jilin Province and their Tectonic Implications

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Acta Geologica Sinica(English Edition) 2009年第2期83卷 245-257页

作者： YU Yang XU Wenliang PEI Fuping YANG Debin ZHAO Quanguo College of Earth Sciences Jilin University Changchun Jilin 130061 China

Zircon U-Pb ages and geochemical analytical results are presented for the volcanic rocks of the Naozhigou, Ergulazi, and Sidaogou Formations in the Linjiang area, southeastern Jilin Province to constrain the nature of magma source and their tectonic settings. The Naozhigou Formation is composed mainly of andesite and rhyolite and its weighted mean ^206pb/^238U age for 13 zircon grains is 222±1 Ma. The Ergulazi Formation consists of basaltic andesite, basaltic trachyandesite, and andesite, and six grains give a weighted mean ^206pb/^238U age of 131±4 Ma. The Sidaogou Formation consists mainly of trachyandesite and rhyolite, and six zircon grains yield a weighted mean ^206pb/^238U age of 113±4 Ma. The volcanic rocks have SIO2=60.24%-77.46%, MGO=0.36%-1.29% （Mg#=0.32-0.40） for the Naozhigou Formation, SIO2=51.60%-59.32%, MGO=3.70%-5.54% （Mg#=0.50-0.60） for the Ergulazi Formation, and SIO2=58.28%-76.32%, MGO=0.07%-1.20% （Mg#=0.14-0.46） for the Sidaogou Formation. The trace element analytical results indicate that these volcanic rocks are characterized by enrichment in light rare earth elements （LREEs） and large ion lithophile elements （LILEs）, relative depletion in heavy rare earth elements （HREEs） and high field strength elements （HFSEs, Nb, Ta, and Ti）, and negative Eu anomalies. Compared with the primitive mantle, the Mesozoic volcanic rocks in the Linjiang area have relatively high initial ^87Sr/^86Sr ratios （0.7053-0.7083） and low εNd（t） values （-8.38 to -2.43）, and display an EMⅡ trend. The late Triassic magma for the Naozhigou Formation could be derived from partial melting of a newly accretional crust with the minor involvement of the North China Craton basement and formed under an extensional environment after the collision of the Yangtze Craton and the North China Craton. The Early Cretaceous volcanic rocks for the Ergulazi and Sidaogou Formations could be formed under the tectonic setting of an active continental margin related to the westward subduction of t

关键词： LA-ICP-MS zircon U-Pb dating geochemistry volcanic rocks magma source tectonicsetting Linjiang area Jilin

In situ U-Pb dating and trace elements of magmatic rutile from Mujicun Cu-Mo deposit,North China Craton:Insights into porphyry mineralization

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China Geology 2024年第4期7卷 730-746页

作者： Fan Yang Jing-wen Mao Wei-dong Ren Jia-run Tu Gilby Jepson Si-yuan Meng Zhi-min Wang MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Key Laboratory of Mineral Resources in Western China(Gansu Province) School of Earth SciencesLanzhou UniversityLanzhou 730000China Tianjin Center China Geological SurveyTianjin 300170China Department of Geosciences University of ArizonaTucson AZ85721USA Hebei Geological Engineering Exploration Institute Baoding 071051China

Porphyry Cu(Mo-Au)deposit is one of the most important types of copper deposit and usually formed under magmatic arc-related settings,whilst the Mujicun porphyry Cu-Mo deposit in North China Craton uncommonly generated within intra-continental *** previous studies have focused on the age,origin and ore genesis of the Mujicun deposit,the ore-forming age,magma source and tectonic evolution remain ***,this study targeted rutile(TiO_(2))in the ore-hosting diorite porphyry from the Mujicun Cu-Mo deposit to conduct in situ U-Pb dating and trace element composition studies,with major views to determine the timing and magma evolution and to provide new insights into porphyry Cu-Mo *** trace element data show flat-like REE patterns characterized by relatively enrichment LREEs and depleted HREEs,which could be identified as magmatic *** U-Pb dating yields lower intercept ages of 139.3–138.4 Ma,interpreted as post magmatic cooling timing below about 500℃,which are consistent or slightly postdate with the published zircon U-Pb ages of diorite porphyry(144.1–141.7 Ma)and skarn(146.2 Ma;139.9 Ma)as well as the molybdenite Re-Os ages of molybdenum ores(144.8–140.0 Ma).Given that the overlap between the closure temperature of rutile U-Pb system and ore-forming temperature of the Mujicun deposit,this study suggests that the ore-forming ages of the Mujicun deposit can be constrained at 139.3–138.4 Ma,with temporal links to the late large-scale granitic magmatism at 138–126 Ma in the Taihang *** on the Mg and Al contents in rutile,the magma of ore-hosting diorite porphyry was suggested to be derived from crust-mantle mixing *** conjunction with previous studies in Taihang Orogen,this study proposes that the far-field effect and the rollback of the subducting Paleo-Pacific slab triggered lithospheric extension,asthenosphere upwelling,crust-mantle interaction and thermo-mechanical erosion,which jointly facilitated

关键词： Rutile U-Pb geochronology Rutile geochemistry Intra-continental porphyry mineralization Paleo-Pacific slab subduction Tectonic evolution magma source Ore-forming age Mujicun Cu-Mo deposit Mineral exploration engineering North China Craton

Geochemistry and Petrogenesis of Basic and Ultrabasic Rocks Elogo Complex in Ivindo Archean Block (Congo Craton): Geodynamic Implications

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Open Journal of Geology 2023年第2期13卷 107-135页

作者： Nelson Lekeba Makamba Vicky Tendresse Télange Bouenitela Ulrich Verne Matiaba-Bazika Florent Boudzoumou Geodynamics Laboratory Faculty of Science and Technology Marien Ngouabi University Brazzaville Republic of the Congo Department of Geosciences National Institute for Research in Exact and Natural Sciences Brazzaville Republic of the Congo

The Elogo complex is a greenstone belt portion located on the Eastern edge of the Archean Congo craton at the junction with the Paleoproterozoic to Neoproterozoic Sembe Ouesso basin. This study was carried out on this complex to determine the context of the placement of basaltic rocks. Metaluminous tholeiitic basalts (basic and ultrabasic), calc-alkaline basalts, andesitic basalts, and peraluminous calc-alkaline dacites represent greenstones. Tholeiitic and calc-alkaline basalts come from deep enriched and depleted mantle sources, including garnet in fusion residues [Al2O3/TiO2 > 16 (16.5 to 35.12) and in some samples between 12.45 to 14.48;CaO/Al2O3 1 (1.04 to 1.35) in ten samples and (Gb/Yb)PM > 1]. The calc-alkaline dacites come from a shallow depleted mantle source [Al2O3/TiO2 > 16;CaO/Al2O3 1]. Tholeiitic and calc-alkaline basalts have a negative Rb, Ba, Ce, and Nb anomaly without negative Ti anomaly, positive Ta, Pb anomalies, and a lack of significant REE [(La/Yb)n = 0.36 to 0.97 and 1 to 2.15;(Ce/Yb)n = 0.27 to 0.96 and 1.04 to 1.72, respectively] fractionation. High Nb/Th (2 to 10) and Nb/U (1.82 to 26) ratios and low La/Ta (5 to 27) ratios are characteristic of divergent margin magmatic sources. Tholeiitic and calc-alkaline basalts correspond to an extensive back-arc basin-type tectonic setting. Calc-alkaline andesitic basalts and dacites show positive Ba, U, Th, K, La, Ce, Pb, and Li anomalies and negative Nb, Ta, and Ti anomalies reflecting crustal contamination and hydrothermal alteration in a compressive tectonic context as a volcanic arc in a subduction regime marking the interruption of the meso-neoarchean Elogo’s opening. Elogo’s opening and closing are probably associated with the emplacement of the greenstone of the meso-neoarchean Gabon Belinga group and the relics of the Mesoarchean greenstones of the Cameroun Ntem complex.

关键词： Elogo Greenstone Archean Tholeiitic Andesitic Basalts Dacites magma source

Petrogenesis of Miocene ultrapotassic rocks in the western Lhasa terrane, Tibetan Plateau: evidence from in situ zircon U–Pb dating, Hf–O isotopes, and whole-rock geochemistry

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Petrogenesis of Miocene ultrapotassic rocks in the western L...