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
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
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
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
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
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
: 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
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
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
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
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
基金the China Postdoctoral Science Foundation the Key Project (No.9502010)of the former Ministry of Geology and Mineral Resources+1 种基金 the National Key BasicResearch Project (No.G1999043211) the NationalScience Foundation of China Outstanding Youth Grant(No.49925306).
文摘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.
基金supported by the National Natural Science Foundation of China grant 49972034the National 973 Project of China grant G1999043211
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
文摘: 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.
文摘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.
基金DST-SERB grant vide Project No.CRG/2020/002635CSIR-JRF fellowship No.09/1236(11154)/2021-EMR-I。
文摘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.
文摘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.
文摘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)。