Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentr...Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentrating district.Recent studies show that the newly discovered Yanshanian porphyry Cu-Mo polymetallic mineralization superimposed in the Indosinian porphyry copper belt in this area.展开更多
Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus ...Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus become an internationally noteworthy gold ore cluster.The gold exploration depth has been increased to about 2000 m from the previous<1000 m.To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m,the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named“Deep drillhole ZK01”to a depth of 3266 m.Hence,as reported herein,the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented.ZK01 is,to date,the deepest borehole with an gold intersect in China,and constitutes a significant advance in deep gold prospecting in China.The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources,while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources.The Jiaojia Fault Belt tends to gently dip downward,having dip angles of about 25°and about 20°at vertical depths of 2000 m and 2850 m,respectively.The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing,alteration,mineralization,and tectonic type.The deep zones can generally be categorized from inside outward as cataclastic granite,granitic cataclasite,weakly beresitized granitic cataclasite,beresitized cataclasite,and gouge.These zones exhibit a gradual transitional relation or occur alternately and repeatedly.The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development;that is,the higher the pyrite content,the wider the veins and the higher the gold grade.Compared to the shallow gold ores,the deep-seated gold ores have higher fineness and contain joseite,tetradymite,and native bismuth,suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization.ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane(gouge)and hosted within the Linglong Granite,contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro.These new discoveries are particularly significant because they can help correct mineralization prospecting models,determine favorable positions for deep prospecting,and improve metallogenic prediction and resource potential evaluation.展开更多
Objective“Orogenic gold deposits,”which account for 30%of global gold resources(Frimmel and Hennigh,2015),is one of the most important types of gold deposits in the world.This kind of gold deposit is supposed to hav...Objective“Orogenic gold deposits,”which account for 30%of global gold resources(Frimmel and Hennigh,2015),is one of the most important types of gold deposits in the world.This kind of gold deposit is supposed to have spatial and temporal distribution association with the accretionary orogenic belt.The Ailaoshan Gold Belt,where there are many large orogenic gold deposits including Jinchang,Daping,Laowangzhai,Donggualing,and Changan,contribute substantially to Chinese gold resources.The Himalayan orogen and Ailaoshan Orogen,both have experienced the early accretionary orogenesis and the subsequent collisional orogenesis are one of the biggest orogenic belts on the earth.Gold mineralization can be divided into that the earlier Yarlung Zangbo suture zone(59–44 Ma)and the later Ailaoshan Orogen(35–26 Ma)(Li et al.,2017),based on previous geochronological studies.In order to find out if there are any connections between these two gold events,we present 40Ar/39Ar data of hydrothermal sericite collected from the Xiachahe gold deposit in the northwest of the Ailaoshan Gold Belt.However,our new geochronology data regards this as a continuous gold mineralization event resulting from the India–Eurasia collision.展开更多
The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassi...The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassic intrusions have been identified in the belt. Apart from the quartz diorite porphyry in the large Xietongmen deposit, the Cu mineralization potential of other Jurassic intrusions in this belt remains unclear. This study presents zircon U–Pb dating and trace elements, apatite major and trace elements as well as published whole-rock geochemical and isotopic data of the Dongga tonalite in the central part of the Gangdese belt, aiming to reveal the petrogenesis, oxidation state, volatile content, and Cu mineralization potential of this intrusion. The Dongga tonalite has a zircon U–Pb age of 179.4 ± 0.9 Ma. It exhibits high whole-rock V/Sc values(8.76–14.6), relatively low apatite CeN/CeN*ratios(1.04–1.28), elevated zircon(Eu/Eu*)Nvalues(an average of 0.44), high Ce4+/Ce3+values(205–1896), and high ?FMQ values(1.3–3.7), collectively suggesting a high magmatic oxygen fugacity. The Dongga tonalite features amphibole phenocrysts, relatively high whole-rock Sr/Y ratios(20.3–58.9), and lower zircon Ti temperatures (502–740 ℃), reflecting a high magmatic water content. Estimation of magmatic sulfur content(0.002–0.024 wt%) based on apatite SO3contents indicates an enriched magma sulfur content. Combined with previous studies and the collected Sr–Nd–Hf isotopes, the Dongga tonalite is derived from juvenile lower crust related with subduction of the Neo-Tethys oceanic slab. When compared with Xietongmen orebearing porphyries, the Dongga tonalite exhibits remarkable similarities with the Xietongmen ore-bearing porphyries in terms of magma source, tectonic background, magmatic redox state, and volatile components, which indicates that the Dongga tonalite has a high porphyry Cu mineralization potential, and therefore, provides important guidance for the future mineralization exploration.展开更多
The Ziyoutun Cu-Au district is located in the Jizhong–Yanbian Metallogenic Belt and possesses excellent prospects. However, the thick regolith and complex tectonic settings present challenges in terms of detecting an...The Ziyoutun Cu-Au district is located in the Jizhong–Yanbian Metallogenic Belt and possesses excellent prospects. However, the thick regolith and complex tectonic settings present challenges in terms of detecting and decomposition of weak geochemical anomalies. To address this challenge, we initially conducted a comprehensive analysis of 1:10,000-scale soil geochemical data. This analysis included multivariate statistical techniques, such as correlation analysis, R-mode cluster analysis, Q–Q plots and factor analysis. Subsequently, we decomposed the geochemical anomalies, identifying weak anomalies using spectrum-area modeling and local singularity analysis. The results indicate that the assemblage of Au-Cu-Bi-As-Sb represents the mineralization at Ziyoutun. In comparison to conventional methods, spectrumarea modeling and local singularity analysis outperform in terms of identification of anomalies. Ultimately, we considered four specific target areas(AP01, AP02, AP03 and AP04) for future exploration, based on geochemical anomalies and favorable geological factors. Within AP01 and AP02, the geochemical anomalies suggest potential mineralization at depth, whereas in AP03 and AP04 the surface anomalies require additional geological investigation. Consequently, we recommend conducting drilling, following more extensive surface fieldwork, at the first two targets and verifying surface anomalies in the last two targets. We anticipate these findings will significantly enhance future exploration in Ziyoutun.展开更多
According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature contin...According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).展开更多
Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed t...Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed the tectonic environment of crustal breakupcaused by mantle diapirism, in which ultramafic-mafic rocks were intruded along beep faultbelts and the superlarge Jinchuan magmatic Cu-Ni sulphide deposit was formed. In theMiddle-Late Proterozoic metallogenic epoch the crust was further broken to form anintracontinental rift, in which the Chenjiamiao style massive Cu-Fe sulphide deposits hosted bybasic volcanic tuff were formed in the lower volcano-sedimentary sequence, while the largesedex type Jingtieshan style Fe-Cu deposits were formed within the upper abyssal carbon-richargillaceous sedimentary sequence. The Early Palaeozoic saw the aulacogen environment, with-in which the Baiyinchang style superlarge massive base and precious metal sulphide depositshosted by quartz keratophyric tuff were formed in the Middle-Late Cambrian rifted island arcand the massive Cu-Zn sulphide deposits and magmatic chromite deposits associated with theophiolite suite were formed in the Early-Middle Ordovician, and the Honggou style massiveCu-Fe sulphide deposits hosted by spilite were formed in the Late Ordovician back-arc basinenvironment. In the Late Palaeozoic-Meso-Cenozoic, the metallogenic province went into anintracontinental orogenic stage characterized by compressive tectonic environment, in whichthere occurred carbonate-quartz vein type and tectono-alteration gold deposits associated withductile-shear structures.展开更多
The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also refe...The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.展开更多
The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 ...The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 respectively, and the average Y/ΣREE ratio is 35.8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43).展开更多
The Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province in the western Yangtze Block, is a key component of the low-temperature metallogenic domain in South China. In this area, more than 400 Pb-Zn deposits hav...The Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province in the western Yangtze Block, is a key component of the low-temperature metallogenic domain in South China. In this area, more than 400 Pb-Zn deposits have been discovered, and the total proven reserves are up to 260 million tons with lead and zinc grade reaching 10%, even up to 30%.展开更多
1 Introduction Rare-metal granites are widely distributed in South China.The Daping porphyritic granitic Ta-Nb deposit,located in the Yongding area of south Fujian province,South China,is a large rare-metal deposit re...1 Introduction Rare-metal granites are widely distributed in South China.The Daping porphyritic granitic Ta-Nb deposit,located in the Yongding area of south Fujian province,South China,is a large rare-metal deposit recently discovered.Few studies have been made of its petrology,mineralogy,geochemistry,chronology and metallogeny.In recent years,several exploratory drillings have been done in this deposit.These drilling holes,from 380 to 600展开更多
The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangt...The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangtiantang pluton are 153.2±1.1 Ma and 135.8±1.2 Ma,respectively.The Ar-Ar anti-isochrone ages of biotite and K-feldspar are 152.5±1.7Ma and 135.4±2.7Ma,respectively.The ages represent the isotopic closure ages of minerals in the pluton.The Zhangtiantang granites are regarded as peraluminous crust-derived type granites to possess the typical geochemical characteristics of calc-alkaline rocks on continental margin,with enriched Si,K,Al(average value of A/CNK as 1.18),HREE,Rb,U,and Th,heavily depleted V,Cr,Co,Ni,Ti,Nb-Ta,Zr,Sr,P,and Ba,strongly negative Eu and common corundum normative(average value of C as 1.84).The εNd(t) values of the Zhangtiantang granite are-5.84 to-7.79,and t2DM values are 1.69 to 1.83 Ga,which indicates partial melting of continental-crust metamorphic sedimentary rocks during the Middle Proterozoic.The cooling history of the Zhangtiantang granitic pluton indicates that the cooling velocity of pluton was faster(about 67℃ /Ma) from zircon(158 Ma) to biotite(152 Ma),and was slower(about12℃ /Ma) from biotite(152.5 Ma) to K-feldspar(135.8 Ma).It can be deduced that the temporal gap(about 10 Ma) between the granite formmation and W-Sn mineralization in South China may be related to ordinary magma-hydrothermal processes by the variational cooling curve of the pluton.The Zhangtiantang pluton was formed in a compressive setting,with differentiation evolution and mineralization occurring in a relative relaxation setting.展开更多
The Emeishan continental flood basalt, which is widespread in Yunnan, Guizhou and Sichuan provinces of Southwest China, is the volcanic product of a Permian mantle plume, and native copper-chalcocite mineralization as...The Emeishan continental flood basalt, which is widespread in Yunnan, Guizhou and Sichuan provinces of Southwest China, is the volcanic product of a Permian mantle plume, and native copper-chalcocite mineralization associated with the basalt is very common in the border area of Yunnan and Guizhou provinces. The mineralization occurred in the tuff intercalation and terrestrial sedimentary rock intercalation which were formed during the main period of basalt eruption. The orebodies are controlled by the stratigraphic position and faults. Metal ore minerals in the ores are mainly native copper, chalcocite and tenorite, with small amounts of chalcopyrite, bomite, pyrite and malachite, and sometimes with large amounts of bitumen, carbon and plant debris. Several decades of ore deposits are distributed in the neighboring areas of the two provinces, while most of them are small-scale deposits or only ore occurrences. By comparing the lead isotopic composition of the ores with that of the wall-rocks, cover and basement rocks of various periods, the source of copper in this type of ore deposits was studied in this paper. The results showed that: (1) The Pb isotopic composition of the ores from ten deposits is absolutely different from that of siliceous-argillaceus rocks of the Upper Permian Xuanwei Formation, limestones of the Lower Permian Series and Carboniferous, Cambrian sandstone-shale and recta-sedimentary rock and dolomite from the upper part of the Meso-Proterozoic Kunyang Group. This indicates that ore lead was derived neither from the cover rock nor from the basement rocks; (2) Although the Neo-Proterozoic Siman dolomite and silicalite, and dolomite in the lower part of the Kunyang Group are similar in Pb isotopic composition to the ores, lead and copper contents in these rocks are very low and they have not made great contributions to copper mineralization; (3) The ores have the same Pb isotopic composition as the basalt, the latter being enriched in copper. These facts indicate that lead and copper were derived from the basalt. According to the regional geological data and the geological-geochemical characteristics of the ore deposits, it is suggested that ore-forming materials were leached out from the basalt. The thickness and buried depth of the basalt and regional tectonic dynamics can affect the formation of large-scale copper deposits. Therefore, exploration for this type of ore deposits should be conducted in the areas from western Yunnan to western Sichuan, where there are developed basalts of great thickness, with extensive tectonic movement and magmatic activity.展开更多
The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristi...The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.展开更多
Xianglushan-type iron deposits are one of the new types of iron deposits found in the Weining Area of Western Guizhou. The iron-bearing rock system is a paleo-weathered crustal sedimentary(or accumulating) stratum bet...Xianglushan-type iron deposits are one of the new types of iron deposits found in the Weining Area of Western Guizhou. The iron-bearing rock system is a paleo-weathered crustal sedimentary(or accumulating) stratum between the top of the Middle-Late Permian Emeishan basalt formation and the Late Permian Xuanwei formation. Iron ore is hosted in the Lower-Middle part of the rock system. In terms of the genesis of mineral deposit, this type of deposit should be a basalt paleo-weathering crustal redeposit type, very different from marine sedimentary iron deposits or continental weathering crust iron deposits. Based on field work and the analytical results of XRD Powder Diffraction, Electron Probe, Scanner Electron Microscope, etc., the geological setting of the ore-forming processes and the deposit features are illustrated in this paper. The ore-forming environment of the deposit and the Emeishan basalt weathering mineralization are also discussed in order to enhance the knowledge of the universality and diversity of mineralization of the Emeishan Large Igneous Province(ELIP), which may be a considerable reference to further research for ELIP metallogenic theories, and geological research for iron deposits in the paleo-weathering crust areas of the Emeishan basalt,Southwestern, China.展开更多
1 Introduction The Sanjiang metallogenic belt is one of the important nonferrous metal metallogenic belts in China,the potential resources of copper,lead,zinc,silver,gold and tin are huge(Zhengqian et al.,1993).In the...1 Introduction The Sanjiang metallogenic belt is one of the important nonferrous metal metallogenic belts in China,the potential resources of copper,lead,zinc,silver,gold and tin are huge(Zhengqian et al.,1993).In the west of Yunnan province has a lot of Yanshanian granite,according to 1:20 million test data,development of granite belt rich in radioactive minerals in the west of Yunnan展开更多
This study was to analyze the mineral elements in famous tea varieties in Sichuan Province. Eighteen mineral elements in the samples of 13 famous tea varieties in Sichuan Province were measured via related instruments...This study was to analyze the mineral elements in famous tea varieties in Sichuan Province. Eighteen mineral elements in the samples of 13 famous tea varieties in Sichuan Province were measured via related instruments. The results showed, of all the 18 measured samples, that the contents of K, P, S, Ca and Mg were relatively higher( 〉1 500 mg/kg) in famous tea varieties in Sichuan Province, while those of Ba, Cr, V, Co and Se were relatively lower( 〈 10 mg/kg) ; compared to common green tea, the famous tea varieties in Sichuan Province contained higher contents of K, Zn, P, Na, Ni, Cu, S, Se and Co(0.38% -115.65% higher than that in common green tea), and lower contents of Mg, Mn, AI, Ca, V, Rb, Fe and Cr(7.20% -46.67% lower than that in common green tea); of the 13 tested tea varieties, Hongyanyingchun, Yongchuanxiuya and Qingchengxueya were rich in mineral elements, while Yuchengyunwu and Yuqiancha lacked in mineral elements. The re- suits show that Hongyanyingchun, Yongchuanxiuya and Qingchengxueya are the elites in the famous tea varieties in Sichuan Province.展开更多
Characteristics and distribution patterns of clastic minerals (0. 063 -0. 125 mm) in bottom sediments represent a significant indi- cator for the identification of the origin of sediment. One hundred and fourteen su...Characteristics and distribution patterns of clastic minerals (0. 063 -0. 125 mm) in bottom sediments represent a significant indi- cator for the identification of the origin of sediment. One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South China Sea, were analysed to identify the mineral suites and their distributions in the study area. The area can be divided into three mineral provinces : (Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll ; ( Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South China Sea; and ( Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from China' s Mainland and do not exceed 17°N, and a mixed mineral subprovince of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons.展开更多
The characteristics and distribution patterns of detrital minerals (0. 063 -0. 125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral compo...The characteristics and distribution patterns of detrital minerals (0. 063 -0. 125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral composition of 219 surface sediment samples was ana- lysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces : (Ⅰ) province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau--Kyushu Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate - acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau--Kyushu Ridge. it is suggested that, ( 1 ) Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. (2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau (e. g. , Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. (3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.展开更多
基金financially supported by the National Natural Science Foundation of China (grant No.41502076)the Leading Talents Plan Project of Science and Technology of Yunnan Province (grant No.2013HA001)the Science Research Fund of Yunnan Provincial Education Department (grant No.2015Y066)
文摘Objective The Geza arc in Yunnan Province,located in the southern Yidun arc,is an important part of the Sanjiang tectonic-magmatic belts in southwestern China and is a newly discovered copper polymetallic ore-concentrating district.Recent studies show that the newly discovered Yanshanian porphyry Cu-Mo polymetallic mineralization superimposed in the Indosinian porphyry copper belt in this area.
基金by the National Natural Science Foundation of China(41772076,41672084,41372086,41503038)the National Key Research and Development Program of China(2016YFC0600105-04,2016YFC0600606)+1 种基金the Key Research and Development Program of Shandong Province(2017CXGC1601,2017CXGC1602,2017CXGC1603),the Special Fund for“Taishan Scholars”Project of Shandong Province.
文摘Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus become an internationally noteworthy gold ore cluster.The gold exploration depth has been increased to about 2000 m from the previous<1000 m.To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m,the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named“Deep drillhole ZK01”to a depth of 3266 m.Hence,as reported herein,the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented.ZK01 is,to date,the deepest borehole with an gold intersect in China,and constitutes a significant advance in deep gold prospecting in China.The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources,while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources.The Jiaojia Fault Belt tends to gently dip downward,having dip angles of about 25°and about 20°at vertical depths of 2000 m and 2850 m,respectively.The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing,alteration,mineralization,and tectonic type.The deep zones can generally be categorized from inside outward as cataclastic granite,granitic cataclasite,weakly beresitized granitic cataclasite,beresitized cataclasite,and gouge.These zones exhibit a gradual transitional relation or occur alternately and repeatedly.The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development;that is,the higher the pyrite content,the wider the veins and the higher the gold grade.Compared to the shallow gold ores,the deep-seated gold ores have higher fineness and contain joseite,tetradymite,and native bismuth,suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization.ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane(gouge)and hosted within the Linglong Granite,contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro.These new discoveries are particularly significant because they can help correct mineralization prospecting models,determine favorable positions for deep prospecting,and improve metallogenic prediction and resource potential evaluation.
基金supported by the National Science Foundation of China(grant No.41772075)the National Key R&D Program of China,Deep Resources Exploration and Mining(grant No.2018YFC0604105).
文摘Objective“Orogenic gold deposits,”which account for 30%of global gold resources(Frimmel and Hennigh,2015),is one of the most important types of gold deposits in the world.This kind of gold deposit is supposed to have spatial and temporal distribution association with the accretionary orogenic belt.The Ailaoshan Gold Belt,where there are many large orogenic gold deposits including Jinchang,Daping,Laowangzhai,Donggualing,and Changan,contribute substantially to Chinese gold resources.The Himalayan orogen and Ailaoshan Orogen,both have experienced the early accretionary orogenesis and the subsequent collisional orogenesis are one of the biggest orogenic belts on the earth.Gold mineralization can be divided into that the earlier Yarlung Zangbo suture zone(59–44 Ma)and the later Ailaoshan Orogen(35–26 Ma)(Li et al.,2017),based on previous geochronological studies.In order to find out if there are any connections between these two gold events,we present 40Ar/39Ar data of hydrothermal sericite collected from the Xiachahe gold deposit in the northwest of the Ailaoshan Gold Belt.However,our new geochronology data regards this as a continuous gold mineralization event resulting from the India–Eurasia collision.
基金supported by the National Natural Science Foundation Program of China(42102095,42362013,42363009)the Jiangxi Provincial Natural Science Foundation(20224BAB203036,20224BAB213040,20224ACB203008)the Open Research Fund Program of State Key Laboratory of Nuclear Resources and Environment,East China University of Technology(2022NRE12).
文摘The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassic intrusions have been identified in the belt. Apart from the quartz diorite porphyry in the large Xietongmen deposit, the Cu mineralization potential of other Jurassic intrusions in this belt remains unclear. This study presents zircon U–Pb dating and trace elements, apatite major and trace elements as well as published whole-rock geochemical and isotopic data of the Dongga tonalite in the central part of the Gangdese belt, aiming to reveal the petrogenesis, oxidation state, volatile content, and Cu mineralization potential of this intrusion. The Dongga tonalite has a zircon U–Pb age of 179.4 ± 0.9 Ma. It exhibits high whole-rock V/Sc values(8.76–14.6), relatively low apatite CeN/CeN*ratios(1.04–1.28), elevated zircon(Eu/Eu*)Nvalues(an average of 0.44), high Ce4+/Ce3+values(205–1896), and high ?FMQ values(1.3–3.7), collectively suggesting a high magmatic oxygen fugacity. The Dongga tonalite features amphibole phenocrysts, relatively high whole-rock Sr/Y ratios(20.3–58.9), and lower zircon Ti temperatures (502–740 ℃), reflecting a high magmatic water content. Estimation of magmatic sulfur content(0.002–0.024 wt%) based on apatite SO3contents indicates an enriched magma sulfur content. Combined with previous studies and the collected Sr–Nd–Hf isotopes, the Dongga tonalite is derived from juvenile lower crust related with subduction of the Neo-Tethys oceanic slab. When compared with Xietongmen orebearing porphyries, the Dongga tonalite exhibits remarkable similarities with the Xietongmen ore-bearing porphyries in terms of magma source, tectonic background, magmatic redox state, and volatile components, which indicates that the Dongga tonalite has a high porphyry Cu mineralization potential, and therefore, provides important guidance for the future mineralization exploration.
基金project was supported by the Enterprise Authorized Item from the Jilin Sanhe Mining Development Co., Ltd. (3-4-2021-120)the Fundamental Research Funds for the Central Universities (2-9-2020-010)。
文摘The Ziyoutun Cu-Au district is located in the Jizhong–Yanbian Metallogenic Belt and possesses excellent prospects. However, the thick regolith and complex tectonic settings present challenges in terms of detecting and decomposition of weak geochemical anomalies. To address this challenge, we initially conducted a comprehensive analysis of 1:10,000-scale soil geochemical data. This analysis included multivariate statistical techniques, such as correlation analysis, R-mode cluster analysis, Q–Q plots and factor analysis. Subsequently, we decomposed the geochemical anomalies, identifying weak anomalies using spectrum-area modeling and local singularity analysis. The results indicate that the assemblage of Au-Cu-Bi-As-Sb represents the mineralization at Ziyoutun. In comparison to conventional methods, spectrumarea modeling and local singularity analysis outperform in terms of identification of anomalies. Ultimately, we considered four specific target areas(AP01, AP02, AP03 and AP04) for future exploration, based on geochemical anomalies and favorable geological factors. Within AP01 and AP02, the geochemical anomalies suggest potential mineralization at depth, whereas in AP03 and AP04 the surface anomalies require additional geological investigation. Consequently, we recommend conducting drilling, following more extensive surface fieldwork, at the first two targets and verifying surface anomalies in the last two targets. We anticipate these findings will significantly enhance future exploration in Ziyoutun.
基金the Major State Basic Research Programs of the People’s Republic of China(No.2001CB409806).
文摘According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).
基金This paper presents part of the result of the project supported by the National Natural Science Foundation of China(No.49272109)and the Foundation for Development of Geological Science and Technology of the Ministry of Geology and Mineral Resources(No.89
文摘Four metallogenic epochs occurred in different tectonic environments during theevolution of the Northern Qilian metallogenic province through the geological time. The Mid-dle Proterozoic metallogenic epoch witnessed the tectonic environment of crustal breakupcaused by mantle diapirism, in which ultramafic-mafic rocks were intruded along beep faultbelts and the superlarge Jinchuan magmatic Cu-Ni sulphide deposit was formed. In theMiddle-Late Proterozoic metallogenic epoch the crust was further broken to form anintracontinental rift, in which the Chenjiamiao style massive Cu-Fe sulphide deposits hosted bybasic volcanic tuff were formed in the lower volcano-sedimentary sequence, while the largesedex type Jingtieshan style Fe-Cu deposits were formed within the upper abyssal carbon-richargillaceous sedimentary sequence. The Early Palaeozoic saw the aulacogen environment, with-in which the Baiyinchang style superlarge massive base and precious metal sulphide depositshosted by quartz keratophyric tuff were formed in the Middle-Late Cambrian rifted island arcand the massive Cu-Zn sulphide deposits and magmatic chromite deposits associated with theophiolite suite were formed in the Early-Middle Ordovician, and the Honggou style massiveCu-Fe sulphide deposits hosted by spilite were formed in the Late Ordovician back-arc basinenvironment. In the Late Palaeozoic-Meso-Cenozoic, the metallogenic province went into anintracontinental orogenic stage characterized by compressive tectonic environment, in whichthere occurred carbonate-quartz vein type and tectono-alteration gold deposits associated withductile-shear structures.
基金jointly funded by the national key research and development program project“Strategic Mineral Information and Metallogenic Regularity of the Tethyan Metallogenic Domain”(2021YFC2901803)a project of the National Natural Science Foundation of China entitled“Geological Structure Mapping and Regional Comparative Study of the Tethyan Tectonic Domain”(92055314),International Geoscience Programme(IGCP-741)a project initiated by the China Geological Survey(DD20221910).
文摘The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far.The Pulang porphyry copper deposit(also referred to as the Pulang deposit)in this area has proven copper reserves of 5.11×106 t.This deposit has been exploited on a large scale using advanced mining methods,exhibiting substantial economic benefit.Based on many research results of previous researchers and the authors’team,this study proposed the following key insights.(1)The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring.This understanding was overturned in this study.Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc,and the mineralization is mainly related to the magmatism of quartz monzonite porphyries.(2)Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit.Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone.Most of them have developed in the potassium silicate alteration zone.The main orebody occurs as large lenses at the top of the hanging wall of rock bodies,with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m(average:187.07 m).It has a copper grade of 0.21%-1.56%(average:0.42%)and proven copper resources of 5.11×10^(6) t,which are associated with 113 t of gold,1459 t of silver,and 170×10^(3) t of molybdenum.(3)Many studies on diagenetic and metallogenic chronology,isotopes,and fluid inclusions have been carried out for the Pulang deposit,including K-Ar/Ar-Ar dating of monominerals(e.g.,potassium feldspars,biotites,and amphiboles),zircon U-Pb dating,and molybdenite Re-Os dating.The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites,quartz monzonite porphyries formed during the mineralization,and post-mineralization granite porphyries,which were formed at 223±3.7 Ma,218±4 Ma,and 207±3.9 Ma,respectively.The metallogenic age of the Pulang deposit is 213‒216 Ma.(4)The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites.The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity.The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust-and mantle-derived magmas.
文摘The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 respectively, and the average Y/ΣREE ratio is 35.8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43).
基金supported by the National 973 project(No.2014CB440905)
文摘The Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province in the western Yangtze Block, is a key component of the low-temperature metallogenic domain in South China. In this area, more than 400 Pb-Zn deposits have been discovered, and the total proven reserves are up to 260 million tons with lead and zinc grade reaching 10%, even up to 30%.
基金supported by MOST of China 2016YFC0600408Investigation of Rare Metal, Rare Earth, and Rare-scattered Mineral Resources in South China (DD20160056)
文摘1 Introduction Rare-metal granites are widely distributed in South China.The Daping porphyritic granitic Ta-Nb deposit,located in the Yongding area of south Fujian province,South China,is a large rare-metal deposit recently discovered.Few studies have been made of its petrology,mineralogy,geochemistry,chronology and metallogeny.In recent years,several exploratory drillings have been done in this deposit.These drilling holes,from 380 to 600
基金supported by the Foundation of Geology Research Projects,funded by the Department of Science and Technology and International Cooperation,Chinese Geological Survey (Grant No. 1212010611805)
文摘The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangtiantang pluton are 153.2±1.1 Ma and 135.8±1.2 Ma,respectively.The Ar-Ar anti-isochrone ages of biotite and K-feldspar are 152.5±1.7Ma and 135.4±2.7Ma,respectively.The ages represent the isotopic closure ages of minerals in the pluton.The Zhangtiantang granites are regarded as peraluminous crust-derived type granites to possess the typical geochemical characteristics of calc-alkaline rocks on continental margin,with enriched Si,K,Al(average value of A/CNK as 1.18),HREE,Rb,U,and Th,heavily depleted V,Cr,Co,Ni,Ti,Nb-Ta,Zr,Sr,P,and Ba,strongly negative Eu and common corundum normative(average value of C as 1.84).The εNd(t) values of the Zhangtiantang granite are-5.84 to-7.79,and t2DM values are 1.69 to 1.83 Ga,which indicates partial melting of continental-crust metamorphic sedimentary rocks during the Middle Proterozoic.The cooling history of the Zhangtiantang granitic pluton indicates that the cooling velocity of pluton was faster(about 67℃ /Ma) from zircon(158 Ma) to biotite(152 Ma),and was slower(about12℃ /Ma) from biotite(152.5 Ma) to K-feldspar(135.8 Ma).It can be deduced that the temporal gap(about 10 Ma) between the granite formmation and W-Sn mineralization in South China may be related to ordinary magma-hydrothermal processes by the variational cooling curve of the pluton.The Zhangtiantang pluton was formed in a compressive setting,with differentiation evolution and mineralization occurring in a relative relaxation setting.
基金support of the Key Orientation Project (No. KZCX2-YW-111) of Chinese Academy of SciencesNational Basic Research Program of China (No. 2007CB411408)
文摘The Emeishan continental flood basalt, which is widespread in Yunnan, Guizhou and Sichuan provinces of Southwest China, is the volcanic product of a Permian mantle plume, and native copper-chalcocite mineralization associated with the basalt is very common in the border area of Yunnan and Guizhou provinces. The mineralization occurred in the tuff intercalation and terrestrial sedimentary rock intercalation which were formed during the main period of basalt eruption. The orebodies are controlled by the stratigraphic position and faults. Metal ore minerals in the ores are mainly native copper, chalcocite and tenorite, with small amounts of chalcopyrite, bomite, pyrite and malachite, and sometimes with large amounts of bitumen, carbon and plant debris. Several decades of ore deposits are distributed in the neighboring areas of the two provinces, while most of them are small-scale deposits or only ore occurrences. By comparing the lead isotopic composition of the ores with that of the wall-rocks, cover and basement rocks of various periods, the source of copper in this type of ore deposits was studied in this paper. The results showed that: (1) The Pb isotopic composition of the ores from ten deposits is absolutely different from that of siliceous-argillaceus rocks of the Upper Permian Xuanwei Formation, limestones of the Lower Permian Series and Carboniferous, Cambrian sandstone-shale and recta-sedimentary rock and dolomite from the upper part of the Meso-Proterozoic Kunyang Group. This indicates that ore lead was derived neither from the cover rock nor from the basement rocks; (2) Although the Neo-Proterozoic Siman dolomite and silicalite, and dolomite in the lower part of the Kunyang Group are similar in Pb isotopic composition to the ores, lead and copper contents in these rocks are very low and they have not made great contributions to copper mineralization; (3) The ores have the same Pb isotopic composition as the basalt, the latter being enriched in copper. These facts indicate that lead and copper were derived from the basalt. According to the regional geological data and the geological-geochemical characteristics of the ore deposits, it is suggested that ore-forming materials were leached out from the basalt. The thickness and buried depth of the basalt and regional tectonic dynamics can affect the formation of large-scale copper deposits. Therefore, exploration for this type of ore deposits should be conducted in the areas from western Yunnan to western Sichuan, where there are developed basalts of great thickness, with extensive tectonic movement and magmatic activity.
基金financially supported by National Natural Science Foundation of China(42272106,41202067)Open Fund of State Key Laboratory for Mineral Deposits Research,Nanjing University(2019-LAMD-K12)China Geological Survey(DD20211386,DD20211392,DD20179603).
文摘The Liwu stratiform copper deposit is located in the northwestern Jianglang dome,western China.Current studies mainly focus on the genetic type and mineralization of this deposit.Detailed fluid inclusion characteristics of metallogenic period quartz veins were studied to reveal the ore-forming fluid features.Laser Raman analysis indicates that the ore-forming fluids is a H_(2)O-NaCl-CH_(4)(-CO_(2))system.Fluid inclusions microthermometry shows a homogenization temperature of 181-375°C and a salinity of 5.26%-16.99%for the disseminated-banded Cu-Zn mineralization;but a homogenization temperature of 142-343°C and a salinity of 5.41%-21.19%for the massive-veined Cu-Zn mineralization.These features suggest a medium-high temperature and a medium salinity for the ore-forming fluids.H-O isotopic data indicates that the ore-forming fluids were mainly from the metamorphic and magmatic water,plus minor formation water.And sulfur isotopic data indicates that sulfur was mainly derived from the formation and magmatic rocks.Metallogenesis of the disseminated-banded mineralization was mainly correlated with fluid mixing and water-rock reaction;whereas that of the massive-veined mineralization was mainly correlated with fluid boiling.The genetic type of the deposit is a medium-high temperature hydrothermal deposit related to magmatism and controlled by shear zones.This study is beneficial to understand the stratiform copper deposit.
基金supported by PMO of Guizhou Institute of Technology for the Study of Iron Deposit Oreforming Rule,Ore-controlling Factors and Ore-forming Predication in the Western Region of Guizhou Province(No.406,2015)PMO of Innovation Team of Guizhou General Institutes of Higher Education for Survey of Underlying Ore Deposit(No.56,2015)+1 种基金the Education Reform of the Guizhou Institute of Technology(No.2015JGY18)the Study for Existing State of Rare Earth Elements in Low Grade Iron Ore from Associated Multi-metal Deposits in Northwest Guizhou(Ref.No.05,2014)
文摘Xianglushan-type iron deposits are one of the new types of iron deposits found in the Weining Area of Western Guizhou. The iron-bearing rock system is a paleo-weathered crustal sedimentary(or accumulating) stratum between the top of the Middle-Late Permian Emeishan basalt formation and the Late Permian Xuanwei formation. Iron ore is hosted in the Lower-Middle part of the rock system. In terms of the genesis of mineral deposit, this type of deposit should be a basalt paleo-weathering crustal redeposit type, very different from marine sedimentary iron deposits or continental weathering crust iron deposits. Based on field work and the analytical results of XRD Powder Diffraction, Electron Probe, Scanner Electron Microscope, etc., the geological setting of the ore-forming processes and the deposit features are illustrated in this paper. The ore-forming environment of the deposit and the Emeishan basalt weathering mineralization are also discussed in order to enhance the knowledge of the universality and diversity of mineralization of the Emeishan Large Igneous Province(ELIP), which may be a considerable reference to further research for ELIP metallogenic theories, and geological research for iron deposits in the paleo-weathering crust areas of the Emeishan basalt,Southwestern, China.
基金supported by the China Nuclear Industry Geological Bureau Foundation (No.201637 and 201638)
文摘1 Introduction The Sanjiang metallogenic belt is one of the important nonferrous metal metallogenic belts in China,the potential resources of copper,lead,zinc,silver,gold and tin are huge(Zhengqian et al.,1993).In the west of Yunnan province has a lot of Yanshanian granite,according to 1:20 million test data,development of granite belt rich in radioactive minerals in the west of Yunnan
文摘This study was to analyze the mineral elements in famous tea varieties in Sichuan Province. Eighteen mineral elements in the samples of 13 famous tea varieties in Sichuan Province were measured via related instruments. The results showed, of all the 18 measured samples, that the contents of K, P, S, Ca and Mg were relatively higher( 〉1 500 mg/kg) in famous tea varieties in Sichuan Province, while those of Ba, Cr, V, Co and Se were relatively lower( 〈 10 mg/kg) ; compared to common green tea, the famous tea varieties in Sichuan Province contained higher contents of K, Zn, P, Na, Ni, Cu, S, Se and Co(0.38% -115.65% higher than that in common green tea), and lower contents of Mg, Mn, AI, Ca, V, Rb, Fe and Cr(7.20% -46.67% lower than that in common green tea); of the 13 tested tea varieties, Hongyanyingchun, Yongchuanxiuya and Qingchengxueya were rich in mineral elements, while Yuchengyunwu and Yuqiancha lacked in mineral elements. The re- suits show that Hongyanyingchun, Yongchuanxiuya and Qingchengxueya are the elites in the famous tea varieties in Sichuan Province.
文摘Characteristics and distribution patterns of clastic minerals (0. 063 -0. 125 mm) in bottom sediments represent a significant indi- cator for the identification of the origin of sediment. One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South China Sea, were analysed to identify the mineral suites and their distributions in the study area. The area can be divided into three mineral provinces : (Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll ; ( Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South China Sea; and ( Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from China' s Mainland and do not exceed 17°N, and a mixed mineral subprovince of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons.
文摘The characteristics and distribution patterns of detrital minerals (0. 063 -0. 125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral composition of 219 surface sediment samples was ana- lysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces : (Ⅰ) province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau--Kyushu Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate - acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau--Kyushu Ridge. it is suggested that, ( 1 ) Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. (2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau (e. g. , Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. (3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.