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Enrichment of Mantle-derived Fluids in the Formation Process of Granitoids: Evidence from the Himalayan Granitoids around Kunjirap in the Western Qinghai-Tibet Plateau 被引量:6
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作者 姜耀辉 凌洪飞 +3 位作者 蒋少涌 周珣若 芮行健 杨万志 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第3期343-350,共8页
Taking the Himalayan granitoids around Kunjirap in the western Qinghai-Tibetplateau as an example, the authors present in this paper the characteristics of the granitoids richin mantle-derived fluid components and dis... Taking the Himalayan granitoids around Kunjirap in the western Qinghai-Tibetplateau as an example, the authors present in this paper the characteristics of the granitoids richin mantle-derived fluid components and discuss their rock-forming mechanism. The research resultsindicate that the rock assemblage of the studied granitoids involves diopside syenite-diopsidegranite-biotite (monzonitic) granite, consisting mainly of K-feldspar, oligoclase, quartz,iron-phlogolite, diopside and edenite. The rocks are rich in mantle-derived fluid components ofvolatiles including F, alkali metal elements such as K, Na, Rb, Sr and Ha, and radiogenicheat-producing elements such as U and Th. They were generated by the influx of mantle-derived fluidsinto the lower crest to give rise to partial melting during the lithosphere thinning in theQinghai-Tibet plateau. 展开更多
关键词 mantle-derived fluid GRANITOID western Qinghai-Tibet plateau
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Gold Content of Mantle-Derived Rocks from Eastern China and Its Implications 被引量:4
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作者 HEYing DONGZhenxin +2 位作者 YUEKefen ZHANGZhanjun WANGXin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第2期212-219,共8页
We have analyzed the gold content of 65 samples of mantle-derived xenoliths and their host rocks from eastern China, which is found to be inhomogeneous, falling in the ranges of 1.0×109-8.2×109 (averaging 3.... We have analyzed the gold content of 65 samples of mantle-derived xenoliths and their host rocks from eastern China, which is found to be inhomogeneous, falling in the ranges of 1.0×109-8.2×109 (averaging 3.8 ×10-9) and 0.2×10-9-5.3×10-9 (averaging 2.7×10-9) in the mantle-derived xenoliths and the host basalts respectively. Except the samples from Wanquan County of Hebei Province and Anding County of Hainan Province, the gold content is the highest on the margins of the North China platform and decreases spatially towards the north and south, and temporally the samples of the Tertiary have a higher gold content than those of the Quaternary. The gold content of the mantle-derived xenoliths and the host Paleozoic kimberlites is 3.8×10-9-180×109and 0.1×10-9-38.0×10-9 respectively, which are higher than that in the mantle-derived xenoliths in basalt and the host Cenozoic basalts. The mantle-derived xenoliths have a higher gold content than the host rocks, but their relativity is not very clear, suggesting that the genetic relationship between them is complex. Our data indicate that the average gold content of the lithospheric mantle in eastern China is approximately equal to or approaching 3.8×10-9, which is lower than the average abundance of the upper mantle (5.0×10-9), higher than the average abundance of the continental crust (3.0×10-9) and only slightly higher than the average abundance of the lower continental crust (3.4×10-9). Except the samples from Hainan Province, the mantle-derived xenoliths in basalts with a high gold content are distributed on the two margins of the North China platform, corresponding to the gold deposits-concentrated districts in northwest Hebei Province and Shandong Province, showing the control by the old continental lithospheric mantle and the lower continental crust on the margins of the North China platform. The gold content of the mantle-derived xenoliths from Hainan Province ranges from 7.1×10-9 to 15×10-9, suggesting that some blocks of the lithospheric mantle in Hainan Province may be derived from the ancient gold-rich lithospheric mantle of western Australia and that Hainan Province may possibly be an important gold deposits-concentrated district. Some mantle-derived xenoliths in kimberlite of Shandong Province have an excessively high gold content amounting to 180×10-9, which provides new evidence for the possibility of 'finding gold deposits near kimberlite pipes or alkali-basalt volcanic vents'. Thererfore, the gold content of the mantle-derived xenoliths may be an indicator to the distribution of gold deposits-concentrated districts. 展开更多
关键词 mantle-derived xenoliths BASALT KIMBERLITE gold content eastern China
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A Study on the Ore-forming Effect of Mantle-derived Fluid 被引量:2
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作者 Meng Qingqiang Wu Jianfeng Zhang Liuping 《Petroleum Science》 SCIE CAS CSCD 2007年第4期44-49,共6页
Based on summarizing of the effect of mantle-derived fluid on the formation of ores, especially on gold ore, and with the latest investigations, such as the formation of ore from the action of shallow-deep fluid, the ... Based on summarizing of the effect of mantle-derived fluid on the formation of ores, especially on gold ore, and with the latest investigations, such as the formation of ore from the action of shallow-deep fluid, the transportation effect of the thermal energy by mantle-derived fluid, this paper mainly aims at the effect of mantle-derived fluid on the generation of hydrocarbons. With the proof from geochemistry and fluid inclusion, it was suggested that the mantle-derived fluid not only supplied source materials for hydrocarbons, but also supplied essential energy and matter necessary for the generation of hydrocarbons. The mantle-derived fluid had a good effect, but at the same time it had an adverse effect under specific conditions, on the formation of reservoirs. This paper also discusses the future direction and significance of studying mantle-derived fluid. 展开更多
关键词 mantle-derived fluid ore-forming effect mantle ore oil and gas accumulation
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The Principles for Discrimination of the Source Composition of Mantle-Derived Igneous Rocks and the Nature of the Mantle Source Region of the Emeishan Basalts 被引量:1
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作者 Wang Yunliang, Li Juchu, Han Wenxi and Wang Wangzhang Chengdu College of Geology, Chengdu, Sichuan Jiang Minxi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1993年第3期315-328,共14页
This paper discusses the discrimination principles. deduction and methods for probing into the source composition of mantle-derived magma. The magmatophile (incompatible) source elements are not all optimal tracers fo... This paper discusses the discrimination principles. deduction and methods for probing into the source composition of mantle-derived magma. The magmatophile (incompatible) source elements are not all optimal tracers for mantle source composition. The ratios of two strong magmatophile elements (D<1) or the ratios of two trace elements with the same D value are not controlled by the formation mode and evolution degree of a magma, but maintain the characteristics of their composition in mantle source region prior to the magma formation. The ratios are related to different mantle-crust structures and dynamics. The mantle source composition of the Emeishan Basalt series is similar to that of the South Atlantic Rio Grande Rise-Walvis Ridge Basalts and Brazil continental-margin basalts. This may indicate that these basalt series might have similar source regions and tectonic environments. 展开更多
关键词 mantle-derived igneous rocks mantle composition trace elements DISCRIMINATION Emeishan basalts
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The Discovery and Study of Mantle-Derived Dunite Inclusions in Hornblende-Diorite in the Handan-Xingtai Area,Hebei 被引量:3
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作者 Xu Wenliang Lin Jingqian Changchun Universily of Earth Sciences, Changchun, Jilin Jiang Minxi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1991年第3期259-269,共11页
Phlogopiie-and diopside-bearing dunite occurs as rounded inclusions in hornblende-diorite. Thepetrofabrics, mineral composition and abundances of the trace elements in the dunite indicate that the inclu-sions were der... Phlogopiie-and diopside-bearing dunite occurs as rounded inclusions in hornblende-diorite. Thepetrofabrics, mineral composition and abundances of the trace elements in the dunite indicate that the inclu-sions were derived from the upper mantle and are the residues of high-degree partial melting of mantlepeirdotite. The study of trace elements in the inclusions and their host rocks shows that the magma was origi-nated from the mantle which was enriched in incompatible elements by mantle metasomatism prior to the par-tial melting. 展开更多
关键词 The Discovery and Study of mantle-derived Dunite Inclusions in Hornblende-Diorite in the Handan-Xingtai Area Hebei
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GEOCHEMISTRY AND TECTONIC ENVIRONMENT AND RESERVOIR FORMATION OF MANTLE-DERIVED NATURAL GAS IN THE SONGLIAO BASIN, NORTHEASTERN CHINA 被引量:2
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作者 LI Zian GUO Zhanqian BAI Zhenguo LIN Ge 《Geotectonica et Metallogenia》 2004年第2期168-182,共15页
During several decades of exploration, a number of mantle-derived natural gas pools have been discovered in the vicinities of deep faults in the Songliao Basin, northeastern China. The natural gas in these pools has a... During several decades of exploration, a number of mantle-derived natural gas pools have been discovered in the vicinities of deep faults in the Songliao Basin, northeastern China. The natural gas in these pools has a δ13C1 value of ?16.50/00 to ?24.20/00, a reversed arrangement in the amount of carbon isotopes in methane and its endogamous products (namely, δ13C1 >δ13C2 >δ13C3 >δ13C4), a 3He/4He value of 1.97 to 2.34×10-6,and an Ar/36Ar value of 1063 to 1949. This indicates a mantle 40 source for the natural gas. The trace elements Cd, In, Te and Re, never found in organic-sourced hydrocarbons, are highly enriched in certain crude oils from the Basin; respectively, concentrations of these elements were found to be 751, 28, 16 and 323 times the average crustal values in China, and this also supports a mantle-derived natural gas origin. The characteristics of mantled-derived magmatic rocks, hydrothermal fluids and gaseous fractions distributed in and near the deep Songliao Basin faults indicate that rifting tectonics is providing the mechanisms for this outgassing of the mantle. Deep extensional (normal) faults provide pathways for upward movement of these materials, and in the Songliao Basin, these deep rift fault zones are associated with reservoir occurrence and cap rock seals, forming good sites for accumulation of mantle-derived natural gas. Furthermore, a layer of low velocity, low density and high conductivity in the deep crust has been identified as a potential reservoir for mantle-derived natural gas. 展开更多
关键词 mantle-derived natural gas GEOCHEMISTRY RIFT fault RESERVOIR formation Songliao Basin
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The Characteristics of Spinels in Mantle-derivedXenoliths in Cenozoic Basalts from Eastern Chinaand Their Thermal States
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作者 DONG Zhenxin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1998年第3期271-281,共11页
: The colours and chemical composition variations of 160 spinels in peridotite and pyroxenite xenoliths from Cenozoic basalts in eastern China and their petrogeneses have been studied in detail. The relationships betw... : The colours and chemical composition variations of 160 spinels in peridotite and pyroxenite xenoliths from Cenozoic basalts in eastern China and their petrogeneses have been studied in detail. The relationships between major elements of spinels are discussed. The equilibrium temperatures, pressures and oxygen fugacities of spinels and their coexisting olivines, orthopyroxenes and clinopyroxenes have been determined using the Brey—kohler's T—P calculation methods (1990) and Ballhaus' fo2 calculation method (1991). The relationships between the composition and the equilibrium temperatures, pressures or oxygen fugacities of spinels in peridotite xenoliths from the basalts and the stable field of the spinels in the upper mantle have been shown. 展开更多
关键词 Cenozoic basalt mantle-derived xenolith SPINEL deep-seated mineral
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GEOCHRONOLOGY AND STRONTIUM,NEODYMIUM ISOTOPE OF MANTLE-DERIVED MAGMATITES FROM THEBU′S GOLD DEPOSIT, NORTHERN XINJIANG,CHINA
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作者 He Bochu Tan Keren Wu Qianhong(Changsha Institute of Geotectonics, Academia Sinica, Changsha, 410013) 《Geotectonica et Metallogenia》 1995年第1期54-62,共9页
Bu’s gold deposit is geographically situated in the northern side of Sawuer Mt., Western Jungar. Magmatites in Bu’s deposit including extrusive and intrusive rocks are widespread and have genetic relationship with t... Bu’s gold deposit is geographically situated in the northern side of Sawuer Mt., Western Jungar. Magmatites in Bu’s deposit including extrusive and intrusive rocks are widespread and have genetic relationship with the deposit. One volcanic suite and two intrusives are studied here. Extrusive products were formed in the Early Carboniferous with a whole-rock Rb-Sr isochron age of 347 Ma and fossil ages, while intrusions have Rb-Sr isochron ages from 310 to 329 Ma and are intrusive into the Lower Carboniferous and Upper Devonian.The isotope parameters I ranges from 0. 7037 to 0. 7046, from -5. 65^+6.67 and more,goes from +5. 65~ +7. 96, displaying that they have similar material sources and are derived from mantle magmas or their derivatives. The continental crust of Zhaisang diwa region may be initially formed in the Late-Proterozoic or even more earlier and grew probably in terms of non-proportionated model like S. China, N. American and other parts in the world. 展开更多
关键词 STRONTIUM and NEODYMIUM ISOTOPE mantle-derived magmatite GEOCHRONOLOGY and Bu’s gold deposit
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Petrogenesis of the Borjuri diorite pluton in the Mikir Massif of Northeast India:implications for post-collisional intermediate magmatism during the Pan-African orogeny
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作者 Tribujjal Prakash Ashima Saikia +1 位作者 Pallabi Basumatary Bibhuti Gogoi 《Acta Geochimica》 EI CAS CSCD 2023年第4期747-764,共18页
The Assam-Meghalaya Gneissic Complex(AMGC)of northeast India contains numerous Pan-African granitic bodies that have been attributed to post-collisional rift-related magmatism.The present study is concerned with the f... The Assam-Meghalaya Gneissic Complex(AMGC)of northeast India contains numerous Pan-African granitic bodies that have been attributed to post-collisional rift-related magmatism.The present study is concerned with the first appraisal of intermediate magmatism(diorite,monzonite,and monzodiorite)found in the Borjuri Pluton of Mikir Massif,which is the eastern extension of AMGC.The diorites are strongly metaluminous and exhibit enriched LREE([La/Yb]N=1.63–7.37)with respect to HREE([Gd/Yb]N=1.95–2.27).The studied rocks do not show any mineralogical or textural indication of metamorphism.Tectonic discrimination diagrams indicate that these rocks originated in a within-plate tectonic setting.The lower Mg#(33.49–38.69),low Cr(below detection limit),and Ni(27–41 ppm)contents along with elemental ratios such as Rb/Sr(0.32–0.95),La/Nb(0.49–4.21),and Nb/Ce(0.11–0.64)suggest a crustal source for the diorites.Discrimination diagrams coupled with elemental ratios suggest that these rocks originated due to partial melting of mafic components in the crust with possible contribution from mantle materials.The P–T conditions of diorite emplacement(7.4 kbar,688℃)were calculated using the amphibole-plagioclase geothermobarometer.Geochemical and geochronological data of the Pan-African felsic plutons reported from the AMGC indicate that these rocks were emplaced in a post-collisional extensional regime.The Borjuri Pluton is in close proximity with the Kathalguri Pluton,which has been reported as a product of PanAfrican magmatism.In view of the numerous extensional Pan-African felsic magmatism reported from the AMGC and based on the close vicinity of the Borjuri diorites with the Kathalguri granites,we speculate that the Borjuri diorites are products of the Pan-African post-collisional magmatism. 展开更多
关键词 Granites Rift-related magmatism Intermediate magmatism Within-plate tectonic setting Kathalguri pluton Assam-Meghalaya Gneissic Complex
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Geothermal Energy--Network of Geoplutonic Power Plants
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作者 Andrzej Pawula 《Journal of Environmental Science and Engineering(A)》 2023年第1期14-26,共13页
The article presents the concept of a network of geoplutonic power plants,the total capacity of which would correspond to the general energy needs of the entire region.A scenario of a regional economy is presented,pro... The article presents the concept of a network of geoplutonic power plants,the total capacity of which would correspond to the general energy needs of the entire region.A scenario of a regional economy is presented,provided with electricity produced from a clean source,without pollutant emissions.Thus,a vision of solving the energy crisis resulting from the planned elimination of fossil energy sources is presented.Such an opportunity appeared after solving the technological problems of deep drilling,exceeding 10 km.The new technology involves extracting heat from HDRs(Hot Dry Rocks)and heating the fluid circulating in a pipe in a closed circuit.The temperature at a depth of 10 km is determined by the regional geothermal gradient.Temperature is in the range of 200-400°C.This is already a zone of degassing magmatic solutions and exothermic chemical reactions.In general,it can be argued that the heat flux density is a function of the distance from magmatic intrusions. 展开更多
关键词 plutonic energy geothermal energy renewable energy sources
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甘肃北山南部早古生代古亚洲洋俯冲作用:来自明舒井埃达克质侵入体锆石U-Pb年龄及地球化学的证据 被引量:1
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作者 王红杰 白建科 +3 位作者 赵海波 程龙 朱黎宽 郭峰 《地质通报》 CAS CSCD 北大核心 2024年第2期376-389,共14页
甘肃北山南部具有重要的构造位置与复杂的构造演化历史,制约着北山造山带大地构造归属研究。北山明舒井埃达克质侵入体位于南部辉铜山以西地区,岩性主要为二长花岗岩、正长花岗岩、花岗闪长岩、石英闪长岩等。对明舒井侵入体中的二长花... 甘肃北山南部具有重要的构造位置与复杂的构造演化历史,制约着北山造山带大地构造归属研究。北山明舒井埃达克质侵入体位于南部辉铜山以西地区,岩性主要为二长花岗岩、正长花岗岩、花岗闪长岩、石英闪长岩等。对明舒井侵入体中的二长花岗岩、正长花岗岩和花岗闪长岩进行LA-ICP-MS锆石U-Pb测年,定年结果分别为423.4±3.4 Ma、425.4±2.3 Ma和437.8±3.5 Ma。岩石SiO2含量多数大于56%(55.53%~64.42%),Al2O3大于15%(15.1%~17.79%),MgO多数小于3%,全部小于6%(2.07%~3.5%),Y和Yb含量均较低,同时轻稀土元素富集,Eu异常不明显,Sr含量较高,具有与埃达克岩相似的特征。综合区域地质背景,认为北山南部志留纪埃达克质侵入岩形成于活动大陆边缘火山弧环境,可能是志留纪古亚洲洋向北消减俯冲背景下岩浆作用的产物,同时发生了大规模的地壳增生。明舒井埃达克质侵入岩体的识别为北山造山带早古生代构造演化提供了重要依据。 展开更多
关键词 埃达克质侵入岩 早古生代 俯冲作用 锆石U-PB年龄 甘肃北山 地质调查工程
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赣西北麦斜岩体岩石成因:来自黑云母矿物化学的约束
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作者 陶继华 杨跃贵 +3 位作者 苏献源 冷成彪 许德如 王帅 《地质论评》 CAS CSCD 北大核心 2024年第S01期171-172,共2页
黑云母是花岗岩常见的暗色矿物之一。黑云母化学成分变化是寄主岩浆固结成岩时不同的物理化学条件下所对应的结果,因此,黑云母化学成分很好地记录了寄主岩浆的属性,对黑云母开展矿物化学成分的研究可以有效地反演寄主岩岩浆演化和成岩... 黑云母是花岗岩常见的暗色矿物之一。黑云母化学成分变化是寄主岩浆固结成岩时不同的物理化学条件下所对应的结果,因此,黑云母化学成分很好地记录了寄主岩浆的属性,对黑云母开展矿物化学成分的研究可以有效地反演寄主岩岩浆演化和成岩过程的物理化学条件,指示岩石的成因类型、岩浆物质来源等信息(Wones and Eugster,1965)。 展开更多
关键词 黑云母 麦斜岩体 花岗岩
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粤北诸广岩体南部铀成矿地质特征及找矿潜力
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作者 李海东 江卫兵 +2 位作者 刘斌 赖静 郭新文 《铀矿地质》 CAS CSCD 2024年第3期442-458,共17页
诸广岩体南部地处闽赣后加里东隆起与湘桂粤北海西印支坳陷刚柔地块结合部,位于东西向南岭铀成矿带与北东向桃山-诸广铀成矿带的交汇部位,自西向东分布有城口、长江、百顺和全安4个矿集区。文章通过对诸广岩体南部区域成矿地质背景、岩... 诸广岩体南部地处闽赣后加里东隆起与湘桂粤北海西印支坳陷刚柔地块结合部,位于东西向南岭铀成矿带与北东向桃山-诸广铀成矿带的交汇部位,自西向东分布有城口、长江、百顺和全安4个矿集区。文章通过对诸广岩体南部区域成矿地质背景、岩浆热液活动、铀源以及控矿因素等成矿地质条件综合分析,同时结合前期已有工作成果,系统梳理了区内铀矿化类型、赋存空间及控矿因素;在此基础上进一步分析了诸广岩体南部铀找矿潜力,提出了以下找矿方向:1)棉花坑、书楼丘、水石等矿床深部及外围是区内成矿最有利地段,为下一步找矿重点地段;2)塘湾矿床深部、企岭、黄沙桥等矿床外围新发现的成矿有利地段可进一步进行扩大或钻探验证;3)对比华南邻区花岗岩外带型成矿地质条件和找矿成果,认为诸广岩体南部外带型铀矿化可作为区内铀矿的重要找矿方向。 展开更多
关键词 铀成矿条件 找矿潜力 矿化特征 控矿因素 诸广岩体南部
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江西金滩岩体花岗岩的侵位深度——来自白云母矿物化学成分的约束
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作者 陶继华 杨跃贵 +2 位作者 张吉源 石争 许德如 《岩石矿物学杂志》 CAS CSCD 北大核心 2024年第4期847-855,共9页
白云母是过铝质花岗岩中常见的矿物,可以用来作为限制岩体侵位深度的压力计矿物。文章利用电子探针对金滩二云母花岗岩中的白云母进行了化学成分分析,通过白云母结晶压力计算获得金滩岩体的侵位压力为4.9×10^(8)~6.1×10^(8)Pa... 白云母是过铝质花岗岩中常见的矿物,可以用来作为限制岩体侵位深度的压力计矿物。文章利用电子探针对金滩二云母花岗岩中的白云母进行了化学成分分析,通过白云母结晶压力计算获得金滩岩体的侵位压力为4.9×10^(8)~6.1×10^(8)Pa,平均5.4×10^(8)Pa,对应的侵位深度为16~20 km,平均18 km。综合前人研究成果认为,华南印支期花岗岩侵位深度普遍为17~19 km,且华南印支期造山加厚的地壳厚度很可能≥50 km,而在燕山期经历了强烈的风化剥蚀去顶作用。这一认识为揭示华南地区相对缺乏印支期火山岩提供了一种新的解释。 展开更多
关键词 华南 花岗岩 金滩岩体 白云母 侵位深度
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粤北贵东岩体及外围花岗岩地质特征对比及其意义
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作者 王春双 刘斌 《中国矿业》 北大核心 2024年第S01期557-565,586,共10页
前人对贵东复式岩体的研究多集中在单个岩体上,而未能对整个岩体地质特征、成矿因素等进行全面对比分析。本文为进一步研究粤北贵东岩体及其外围花岗岩体的铀成矿差异的原因,通过对贵东岩体及其外围花岗岩体的地质特征、岩浆演化期次、... 前人对贵东复式岩体的研究多集中在单个岩体上,而未能对整个岩体地质特征、成矿因素等进行全面对比分析。本文为进一步研究粤北贵东岩体及其外围花岗岩体的铀成矿差异的原因,通过对贵东岩体及其外围花岗岩体的地质特征、岩浆演化期次、矿物学特征及地球化学特征等方面进行系统研究分析。研究结果表明:在岩浆演化过程中,岩浆结晶粒度的变化,反映在矿物成分上含量上,主要表现为石英含量逐渐增加,斜长石含量逐渐减少,并且中长石逐渐被钠长石取代,黑云母被白云母替换而含量降低;贵东岩体中西部与东部花岗岩相比,角闪石、斜长石的含量偏大,自变质和交代蚀变较弱,东部花岗岩的矿物组成中基本不含角闪石,斜长石的含量总体上偏低,自变质和交代蚀变较强;地球化学特征表明西-中部岩体属亚碱弱过铝质的花岗岩体,东部及外围属亚碱弱过铝质-过铝质的花岗岩体,说明西-中部岩体在形成过程中可能有少量幔源组分的加入,认为其并非同源物质不同程度部分熔融产物,而是不同源区物质经部分熔融形成。 展开更多
关键词 花岗岩体 贵东复式岩体 地质特征对比 物源 粤北
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安徽铜陵桂花冲铜金矿床的成矿条件与找矿潜力
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作者 刘军 周涛发 +3 位作者 范裕 陈静 熊燕云 刘杰添 《合肥工业大学学报(自然科学版)》 CAS 北大核心 2024年第8期1068-1079,共12页
桂花冲矿床位于铜陵矿集区和繁昌火山岩盆地之间的过渡区,是长江中下游成矿带中新类型的铜金多金属矿床。矿体主要呈透镜状、脉状,分别赋存于桂山岩体与三叠系南陵湖组灰岩地层的接触带和远端碳酸盐地层裂隙中。文章通过记录野外地质工... 桂花冲矿床位于铜陵矿集区和繁昌火山岩盆地之间的过渡区,是长江中下游成矿带中新类型的铜金多金属矿床。矿体主要呈透镜状、脉状,分别赋存于桂山岩体与三叠系南陵湖组灰岩地层的接触带和远端碳酸盐地层裂隙中。文章通过记录野外地质工作及全岩地球化学特征,开展锆石U-Pb定年研究,发现矿区内青山岩体(花岗闪长斑岩)是成矿前岩体,桂山岩体(石英二长斑岩)是成矿岩体。对比铜陵—繁昌过渡区内姚家岭大型矿床研究发现,青山岩体与姚家岭早期岩体形成时代在140 Ma左右,青山岩体可能为姚家岭早期岩体延伸至桂花冲区域,后被推覆至地表;桂山岩体与姚家岭晚期岩体为成矿岩体,形成时代在138 Ma左右,两者可能在深部相连,是同一岩体的不同岩枝。综合桂花冲矿床控矿因素和成矿条件分析,探究该类矿床的成矿潜力和勘探方向,分析表明,在铜陵—繁昌过渡区的碳酸盐地层层间裂隙、褶皱滑脱区域、地层岩性显著变化位置以及形成时代在138 Ma左右的石英二长斑岩与黄龙组、栖霞组、孤峰组、大隆组、南陵湖组碳酸盐地层的接触带具有较好的找矿潜力。 展开更多
关键词 锆石U-PB定年 地球化学 桂花冲矿床 铜陵—繁昌过渡区 青山岩体 桂山岩体
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琼西南晚白垩世千家岩体矿物学特征及其对岩石成因的约束
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作者 陈沐龙 吕昭英 +7 位作者 马昌前 薛桂澄 何玉生 魏昌欣 袁勤敏 黄武轩 常振宇 吕嫦艳 《地质通报》 CAS CSCD 北大核心 2024年第4期503-515,共13页
千家岩体为海南岛典型的晚白垩世早期花岗质杂岩体,岩石类型主要有花岗闪长岩、二长花岗岩及正长花岗岩,常见造岩矿物有黑云母、角闪石、斜长石、碱性长石、石英等。为进一步揭示岩石形成过程及源区性质,反演壳幔相互作用,本文选取千家... 千家岩体为海南岛典型的晚白垩世早期花岗质杂岩体,岩石类型主要有花岗闪长岩、二长花岗岩及正长花岗岩,常见造岩矿物有黑云母、角闪石、斜长石、碱性长石、石英等。为进一步揭示岩石形成过程及源区性质,反演壳幔相互作用,本文选取千家岩体,利用电子探针技术对不同岩石类型中的主要矿物进行了矿物化学分析。结果显示,角闪石、黑云母均属于壳幔混源成因,斜长石发育正反环带及振荡环带,记录了岩浆混合作用的影响。镜下观察发现,千家岩体各类岩石中存在大量的岩浆不平衡结构,如斜长石和角闪石的环带结构,针状产出的磷灰石,以及斜长石、钾长石和石英的嵌晶结构等,结合暗色微粒包体的分布组合及形态特征,认为千家岩体形成中经历了岩浆混合作用。综合来说,岩石及矿物化学证据均表明,岩浆混合作用是研究区岩石形成的主因,矿物学证据表明,千家岩体岩石类型为I型花岗岩,其源区属钙碱性岩浆,黑云母矿物化学数据表明岩石形成环境为相对较低的氧逸度。 展开更多
关键词 晚白垩世 海南岛 千家岩体 矿物学 壳幔混合 地质调查工程
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胶东中生代岩浆岩金等元素组成及其对金成矿的启示 被引量:1
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作者 董磊磊 白鑫 宋明春 《黄金科学技术》 CSCD 北大核心 2024年第5期768-780,共13页
胶东地区是我国最大的金成矿区,但是关于其巨量金的来源一直不明。通过对成矿前的晚侏罗世玲珑期岩体(玲珑、昆嵛山)、早白垩世早期郭家岭期岩体及其暗色包体(郭家岭、丛家)以及成矿后的早白垩世晚期伟德山型岩体及其暗色包体(崂山、牙... 胶东地区是我国最大的金成矿区,但是关于其巨量金的来源一直不明。通过对成矿前的晚侏罗世玲珑期岩体(玲珑、昆嵛山)、早白垩世早期郭家岭期岩体及其暗色包体(郭家岭、丛家)以及成矿后的早白垩世晚期伟德山型岩体及其暗色包体(崂山、牙山、艾山等)的Au、Cu和Ag等元素含量进行分析,发现这些亲铜元素相对于大陆地壳较为亏损。此外,玲珑期和伟德山期样品中Cu/Ag比值与Cu含量具有明显的正相关性。而郭家岭期岩体及其包体中以及伟德山期岩体中的暗色包体中,Cu/Ag比值与Au含量具有正相关性,表明在岩浆演化过程中,单硫化物固溶体从岩浆中持续分离,造成中生代岩浆岩具有较低的Cu/Ag比值和金属含量。这些硫化物的堆晶在中下地壳形成了富集Au等元素的矿源层,为胶东金成矿提供了物质基础。研究还表明,单硫化物固溶体分离是岩浆演化过程中普遍发育的现象,这种现象也可能是导致大陆地壳相对于地幔亏损Cu等元素的原因。 展开更多
关键词 胶东 金成矿 硫化物堆晶 玲珑岩体 郭家岭岩体 伟德山岩体
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宜春Ta-Nb与黄山Nb-Ta矿床成矿元素差异性富集的因素研究
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作者 王雪娜 陈喜连 +5 位作者 陈龙 许德如 邹少浩 万泰安 王国建 李博 《大地构造与成矿学》 EI CAS CSCD 北大核心 2024年第3期597-620,共24页
宜春、黄山地区均位于华南板块钦杭结合带上。宜春Ta-Nb矿床与雅山岩体密切相关,为富Ta的Ta-Nb矿床,赋矿矿物主要为钽锰矿和铌钽锰矿;黄山Nb-Ta矿床与黄山岩体密切相关,为富Nb的Nb-Ta矿床,赋矿矿物以铌铁矿和铌钽铁矿为主。目前,二者在... 宜春、黄山地区均位于华南板块钦杭结合带上。宜春Ta-Nb矿床与雅山岩体密切相关,为富Ta的Ta-Nb矿床,赋矿矿物主要为钽锰矿和铌钽锰矿;黄山Nb-Ta矿床与黄山岩体密切相关,为富Nb的Nb-Ta矿床,赋矿矿物以铌铁矿和铌钽铁矿为主。目前,二者在成矿元素上差异性富集的原因尚不清楚。本文在详细的岩相学观察基础上,对雅山和黄山岩体多期岩相中的云母进行主量和微量元素分析,并结合前人研究,综合探讨控制成矿元素Nb、Ta差异性富集的关键因素。雅山岩体为强过铝质S型花岗岩,具有高Al低碱、P和Li含量较高的特征,岩浆源区以古老地壳物质为主且源区熔融温度相对较低。黄山岩体为准铝质‒过铝质花岗岩,具有相对低Al高碱、P和Li含量低的特征,Zr+Nb+Ce+Y值为345~876μg/g,是典型的A型花岗岩,成岩岩浆主要来源于古老地壳部分熔融,且有相对较多新生地壳或地幔物质的参与,源区熔融温度较高。雅山岩体稀土元素总量较低,具有强烈的Eu负异常和明显的四分组效应;Nb/Ta值(0.32~4.91)、Zr/Hf值(3.96~32.0)较低,Rb/Ba值(1.06~6500)和Rb/Sr值(6.08~22750)较高,显示极高分异的特征;云母中的Ⅳ(F)平均值为–0.17,Ⅳ(Cl)平均值为–2.39,F富集程度较高,Cl富集程度较低。与之对比,黄山岩体稀土元素总量较高,呈现较强的Eu负异常和四分组效应;Nb/Ta值(3.80~45.2)、Zr/Hf值(13.3~30.1)较高,Rb/Ba值(2.61~136)和Rb/Sr值(9.46~521)较低,显示分异程度较高,但低于雅山岩体;云母中Ⅳ(F)平均值为0.01,Ⅳ(Cl)平均值为–3.52,F富集程度相对较低,较富集Cl挥发分。综上,岩浆富Al贫碱,分异演化极高,富F、P、Li,是形成富Ta的Ta-Nb矿床的重要因素;而岩浆贫Al富碱,分异演化较高,较富F、Li,贫P,且有更高比例新生地壳或地幔物质的加入,则有利于形成富Nb的Nb-Ta矿床。本研究认为岩浆源区及熔融温度、构造背景、岩浆演化程度、岩浆成分综合控制了宜春和黄山矿床Nb、Ta成矿元素的差异性富集,对今后指导找矿勘查具有重要的指示意义。 展开更多
关键词 铌钽矿床 雅山岩体 黄山岩体 云母 地球化学特征
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幔源岩浆持续提供热的有力证据:以湘南九嶷山花岗岩体中暗色包体成因研究为例
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作者 张斌武 郭春丽 +1 位作者 陈振宇 许以明 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第4期1061-1086,共26页
湘南九嶷山复式花岗岩体位于南岭西段,由一个加里东期岩体和四个燕山期岩体组成。其西侧金鸡岭岩体中广泛发育形态多样的暗色包体。本次选取一个2m×2.5m不规则椭球形包体开展研究,发现它与寄主岩具有较为相近的年龄、矿物组合、地... 湘南九嶷山复式花岗岩体位于南岭西段,由一个加里东期岩体和四个燕山期岩体组成。其西侧金鸡岭岩体中广泛发育形态多样的暗色包体。本次选取一个2m×2.5m不规则椭球形包体开展研究,发现它与寄主岩具有较为相近的年龄、矿物组合、地球化学和同位素特征:(1)SIMS锆石U-Pb定年结果显示寄主岩和暗色包体的年龄分别为154.0±1.6Ma和151.4±2.1Ma,两者在误差范围内一致;(2)两者均以钾长石、石英、斜长石、黑云母、磷灰石、锆石等为主要的矿物组成,但在矿物组成比例、粒度和形态上有所差距;(3)寄主岩和暗色包体的SiO2含量分别为70.9%~75.6%和67.3%~68.0%,两者均富集大离子亲石元素(LILE)而亏损高场强元素(HFSE),但暗色包体的LILE略低于寄主岩而HFSE略高于寄主岩;(4)寄主岩的εHf(t)值和δ18O值分别为-8.6~-0.4和7.8‰~8.9‰,包体的εHf(t)值和δ18O值分别为-7.0~+1.6和7.3‰~8.9‰。这些特征表明,金鸡岭暗色包体是由富钾的下地壳玄武质变质火成岩在受到幔源岩浆持续加热后发生部分熔融,熔融产物注入到已存在于中上地壳的岩浆房中(寄主岩)后发生淬冷作用形成的。尽管寄主岩和暗色包体均是下地壳物质发生部分熔融的产物,但地壳成分的不均一性导致两者拥有略有差异的同位素和元素组成。沿南岭郴州-临武北东走向断裂带从南向北依次分布有姑婆山、铜山岭、九峰、骑田岭、宝山、锡田花岗质岩体,其所含暗色包体的εHf(t)和δ18O值从亏损(+8、5‰)到富集(-8、9‰)变化范围很大,表明南岭地区暗色包体成因模式具有多样性,但无论是哪种类型,幔源岩浆的长期活动持续为下地壳的熔融和岩浆房演化提供热量是一个必不可少的重要因素。 展开更多
关键词 暗色包体 金鸡岭花岗岩体 九嶷山复式岩体 南岭地区 华南地区
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