Paleoproterozoic potassic granitoids in the southern Sushui Complex from the Zhongtiao Mountains yielded SHRIMP zircon U-Pb ages of 1968-1944 Ma. Lithologically, the potassic granitoid series consists chiefly of monzo...Paleoproterozoic potassic granitoids in the southern Sushui Complex from the Zhongtiao Mountains yielded SHRIMP zircon U-Pb ages of 1968-1944 Ma. Lithologically, the potassic granitoid series consists chiefly of monzodiorite, quartz monzonite and syenogranite. Their trace elements and Sm-Nd isotope characteristics indicate that they were derived from partial melting of Archean TTG rocks in an overthickened continental crust. Petrogenesis of this potassic granitoid series implies a collisional environment within the Trans-North China Orogen in the Paleoproterozoic, which supports a tectonic model of Eastern and Western Continental Blocks being amalgamated in the Paleoproterozoic.展开更多
The Nangqên basin is one of the Tertiary pull-apart basins situated in the east of the Qiangtang block. Similar to the adjacent Dengqên basin and Baxoi basin, there occurred a series of potassic volcanic and...The Nangqên basin is one of the Tertiary pull-apart basins situated in the east of the Qiangtang block. Similar to the adjacent Dengqên basin and Baxoi basin, there occurred a series of potassic volcanic and sub-volcanic rocks, ranging from basic, intermediate to intermediate-acid in lithology.展开更多
The geochemical characteristics of the Cenozoic volcanic rocks from the north Pulu, east Pulu and Dahongliutan regions in the west Kunlun Mountains are somewhat similar as a whole. However, the volcanic rocks from the...The geochemical characteristics of the Cenozoic volcanic rocks from the north Pulu, east Pulu and Dahongliutan regions in the west Kunlun Mountains are somewhat similar as a whole. However, the volcanic rocks from the Dahongliutan region in the south belt are geochemically distinguished from those in the Pulu region (including the north and east Pulu) of the north belt. The volcanic rocks of the Dahongliutan region are characterized by relatively low TiO2 abundance, but more enrichment in alkali, much more enrichment in light rare earth elements and large ion lithosphile elements than those from the Pulu region. Compared with the Pulu region, volcanic rocks from the Dahongliutan region have relatively low 87Sr/86Sr ratios, and high εNd, 207Pb/204Pb and 208Pb/204Pb. Their trace elements and isotopic data suggest that they were derived from lithospheric mantle, consisting of biotite- and hornblende-bearing garnet lherzolite, which had undertaken metasomatism and enrichment. On the primitive mantle-normalized patterns, they display remarkably negative Nb and Ta anomalies, indicating the presence of early-stage subducted oceanic crust. The metasomatism and enrichment resulted from the fluid released from the crustal materials enclosed in the source region in response to the uplift of asthenospheric mantle. Based on the previous experiments it can be inferred that the thickness of the lithosphere ranges from 75 to 100 km prior to the generation of the magmas. However, the south belt differs from the north one by its thicker lithosphere and lower degree of partial melting. The different thickness of the lithosphere gives rise to corresponding variation of the degree of crustal contamination. The volcanic rocks in the south belt are much more influenced by crustal contamination. In view of the tectonic setting, the generation of potassic magmas is linked with the uplift of asthenosphere resulted from large-scale thinning of the lithosphere after the collision of Indian and Eurasian plates, whereas the thinning of the lithosphere may result from delamination. The potassic magmas mainly resulted from partial melting of lithosphere mantle caused by the uplift of asthenosphere.展开更多
Post-collisional potassic and ultrapotassic volcanic rocks are widely distributed across the Tibetan Plateau, and they are considered to be indicators of evolving mantle dynamics. A suite of potassic basalts younger t...Post-collisional potassic and ultrapotassic volcanic rocks are widely distributed across the Tibetan Plateau, and they are considered to be indicators of evolving mantle dynamics. A suite of potassic basalts younger than 55 Ma from the Saga area of western Tibet has been reported. The geochemical characteristics of these rocks distinguish themselves from other potassicltrapotassic volcanic rocks in Tibet, such as positive Nb, Ta, and Ti anomalies and strong enrichment in large ion lithophile elements (LILE), suggesting that phlogopite, rutile and/or sphene might have originated from the mantle source. These basalts are also characterized by a very wide range of 87Sr/86Sr ratios (0.709 043-0.711 915) and relatively high 143Nd/,44Nd ratios (0.512 426-0.512 470,εNd=-4.60 to -3.87). We propose a petrogenetic model for the Saga potassic rocks in which the lithospheric mantle source was infiltrated by a volatilerich (H2O, CO2) and low-degree silicate melt derived from the asthenosphere in the Middle to Late Proterozoic. After the initial Indo-Asian collision, Neo-Tethyan slab breakoff resulted in the partial melting of the previously metasomatized lithospheric mantle and the formation of the Saga potassic rocks. It is likely that the eruption of these volcanic rocks lasted at least 10 Ma.展开更多
A novel 3D coordination compound of K（H2TDA）（H20） （1） （H3TDA = 1H-1,2,3-triazole-4,5-dicarboxylic acid） has been prepared and characterized by IR spectroscopy, elemental analysis, ICP and single-crystal X-ray ...A novel 3D coordination compound of K（H2TDA）（H20） （1） （H3TDA = 1H-1,2,3-triazole-4,5-dicarboxylic acid） has been prepared and characterized by IR spectroscopy, elemental analysis, ICP and single-crystal X-ray diffraction. Compound 1 displays strong fluorescent emission at room temperature.展开更多
The North China Craton(NCC)is one of the most complex cratons in the world.It underwent a series of tectonothermal events during the Neoarchean-Paleoproterozoic.The petrogenesis of potassic granitoids,the timing,and t...The North China Craton(NCC)is one of the most complex cratons in the world.It underwent a series of tectonothermal events during the Neoarchean-Paleoproterozoic.The petrogenesis of potassic granitoids,the timing,and the style of Archean crustal growth are still debated.Systematic field and petrological stdudies on the potassic meta-granites from the Guyang-Chayouzhongqi region were carried out.New U-Pb ages,zircon Lu-Hf isotopic analyses,and whole-rock geochemical data were obtained.Two groups(~2.7 Ga and~2.5 Ga)of potassic meta-granites were recognized.The~2.7 Ga meta-granites are mainly A2-type,with variableεHf(t)values(-8.4 to+3.3)and Archean one stage model ages(T_(DM)=~3.0 Ga),indicating that their source was derived from ancient anatectic TTG-like granite and depleted mantle,which suggests that thin crust had formed in the Guyang-Chayouzhongqi region by~3.0 Ga.Similar to the K-rich granites in the NCC,most of the~2.5 Ga potassic meta-granites are typical of A1-type granite,and are enriched in Sm and Gd and depleted in Nb,Ta,P,and Ti.The ages and isotopic data indicate that the~2.5 Ga meta-granites were generated from juvenile crustal sources with Neoarchean TTGs.The overall zircon U-Pb and Hf isotopic data furthermore suggested that the~2.7 Ga event is the most important stage of magmatic accretion in the NCC,similar to other cratons.In contrast,reworking or metamorphic alteration was the main crustal process in the NCC at~2.5 Ga.展开更多
1 Introduction Songxian at East Qinling mountains in China possesses more than 100 million tons potassic syenite with the average K2O content of 13%and the main mineral phase of K-feldspar which is a kind of potential...1 Introduction Songxian at East Qinling mountains in China possesses more than 100 million tons potassic syenite with the average K2O content of 13%and the main mineral phase of K-feldspar which is a kind of potential potassium展开更多
The medium- to coarse-grained and porphyritic granitoid of Dharmawaram, Karimnagar district, Andhra Pradesh, south India is a biotite-hornblende granite with notable contents of rare metal (Zr, Hf, Th) and rare earth ...The medium- to coarse-grained and porphyritic granitoid of Dharmawaram, Karimnagar district, Andhra Pradesh, south India is a biotite-hornblende granite with notable contents of rare metal (Zr, Hf, Th) and rare earth (including Y) minerals like zircon, thorite, allanite, monazite and xenotime. Chemically, it is metaluminous (average A/ C+N+K = 0.95)-type, potassic (av. 5% K2O) granite, with dominantly sub-alkaline characters. It shows up to 8 times enrichment of rare metals (Zr, Hf, U, Th) and rare earths (including Y, Sc), with reference to their abundances in normal unevolved granite, and hence, fertile for some of these elements. Field, petrological, geochemical and isotopic data of potassic granite (PG) indicate involvement of silica-rich metasedimentary-basic crustal rocks (amphibole-quartzite, amphibolite, hornblende-biotite gneiss, etc.) in its genesis, at a depth range of 30 km. Further, chondrite-normalized REE patterns demonstrate that low-degree partial melting of source rocks is the major controlling factor in the genesis of PG Mild negative Eu-anomaly (av. Eu/Eu* = 0.48), plots of Ba-Rb-Sr in the field of anomalous granite and K/Rb ratios (av. 239) in the range that is shown by normal unevolved granite together indicate less fractionated nature of the PG Limited fractionation of metalumination-type, involving hornblende, led to occasional weak alumina saturation. Interestingly, geochemical and petrogenetic features of the studied PG broadly match with those potassic granites which are already known to host anomalously high enrichment of rare metals and rare earths in other parts of Andhra Pradesh and adjoining Karnataka.展开更多
This study used trace elements in olivine as a new petrogenetic indicator to further constrain the petrogenesis of potassic basalts from the Erkeshan-Wudalianchi-Keluo-Xiaogulihe potassic volcanic field （EWKX for sh...This study used trace elements in olivine as a new petrogenetic indicator to further constrain the petrogenesis of potassic basalts from the Erkeshan-Wudalianchi-Keluo-Xiaogulihe potassic volcanic field （EWKX for short） in the Songliao Basin of NE China,with a combination of the previous olivine and whole-rock geochemical data.展开更多
Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Ow...Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Owing to the limited arable land in China, a vital measure to feed the country’s increasing population is the augmentation of fertilizers so as to gain higher per unit area grain yields. At present, for a fairly long time to come, additional fertilizer resources will mainly come from nitrogen, phosphorus and potassium fertilizers. But there is a severe application disproportion between nitroge-展开更多
The Neoproterozoic quartz potassic syenite of the Iwo area,Southwestern Nigeria has been investigated for its magmatic history and zircon saturation temperature.The zircon morphology showed irregular shapes with secto...The Neoproterozoic quartz potassic syenite of the Iwo area,Southwestern Nigeria has been investigated for its magmatic history and zircon saturation temperature.The zircon morphology showed irregular shapes with sectoral and oscillatory micro zoning.The majority of the zircon grains have embayment,which corresponds to magmatic resorption.The syenite crystallized from probably multiple recharge of less evolved magma.Both the magma injection and subsequent crystallization of the rock occurred over a length of time giving the rock some degree of protracted thermal history and slight fluctuation in chemistry,which are manifested as zonation in the analyzed zircon grains.The initial stage of zircon crystallization was marked by a lower cerium anomaly than the final stage,which indicates changes from lower oxidizing to higher oxidizing conditions.The protracted history does not affect the europium anomalies at any stage of crystallization.An average zircon saturation temperature of 865℃estimated from titanium in zircon(T_(Tiz)℃)thermometer using titanium activity of 0.7(^(a)TiO_(2)~0.7)is taken as reasonable crystallization temperature of the rock.This is fairly consistent with 877℃deduced from the zircon solubility model.The titanium in zircon temperature of 910℃at aTiO_(2)~1 is rather too high to be a useful estimate.Both the temperatures 865 and 877℃are however consistent with those of intermediate rocks.The size of the syenite and protracted crystallization history would have made the temperature to have impacted the metamorphic envelope around the syenite.展开更多
It is revealed that the protolith of gray-light brown potash-feldspar-leucogranulites and granulites in the 2nd formation of the LG in Tanyaokou deposit are quartz kerotophyre of synsedimentary eruption based on the f...It is revealed that the protolith of gray-light brown potash-feldspar-leucogranulites and granulites in the 2nd formation of the LG in Tanyaokou deposit are quartz kerotophyre of synsedimentary eruption based on the following facts and features: (1) The rocks look compact and homogeneous without obvious crystals with naked eyes; (2) they contain blastoporphyritic or glomeroporphyritic and blasto-crystalloclastic crystals consisting of quartz with wavy extinction and albite with obvious alteration and deformation; (3) they also contain radiated and fibrous blasto-microspherulitic texture and swallow-tailed bifurcate and blasto-hollow-skeleton crystal texture, representing the rapid cooling characteristic of the magma during submarine volcanic eruption; (4) the major chemical compositions of the rocks are: SiO2 = 70.80%―76.00%, K2O (4.83%―6.22%)>Na2O(2.78%―3.80%), and K2O+Na2O = 8.63%―9.00%; and (5) their petro-chemical diagrams indicate that they are volcanic rocks. Together with the characteristic that they occur in the same sequence with potassic spilite (SiO2 = 46.12%―50.68%, K2O = 4.23%―5.93%>Na2O = 2.15%―3.14%, K2O+Na2O = 6.51%―8.08%), it can be confirmed that the vol-canics occurring in the 2nd Formation of the LG in Tanyaokou district are double-peaking potas-sic volcanic rocks. The discovery, together with the tuffs with ore minerals and the distribution of lead isotopic as well as the value of Co/Ni of pyrites >1 showing the obvious endogenic metali-zation, can prove that the Tanyaokou deposit is an untypical SEDEX-type deposit formed in the extension fault basin in the Mesoproterozonic aulacogen of the northern margin of the North China Platform, and its metallogenesis is related to the synsedimentary volcanic activities and the hydrothermal exhalation, and both the ore-forming material source and volcanics came from mantle or lower crust. These facts mentioned above, together with the meta-volcanic rocks (double-peaking) found in the Dongshengmiao and Huogeqi districts and the host stratigraphic sequence of LG, can further prove that the Mesoproterozoic aulacogen of passive continental margin of Langshan-Zhaertaishan area had been unevenly expanded. This provides some in-formation and new approaches for the study on tectonic-hydrothermal events in Lang-shan-Zhaertaishan aulacogen and their evolutionary process, hydrothermal dynamical source, the relationship between the volcanic activities and the ore-forming process, the regional ore-forming regularity as well as for the correlation with the similar deposits abroad.展开更多
It is believed that the albite-potash-feldspar-greenschists in the middle Proterozoic Langshan Group in Tanyaokou District are synsedimentary potassic spilite （or poenite） based on the following facts and features: ...It is believed that the albite-potash-feldspar-greenschists in the middle Proterozoic Langshan Group in Tanyaokou District are synsedimentary potassic spilite （or poenite） based on the following facts and features: （ ⅰ ） they occur in beds and look blackish （or apple） green and compact; （ ⅱ ） they bear blasto-glomeroporphyritic and blastocrystalloclastic crystals which consist of （altered） albite laths with hollow skeleton crystal texture in which there are slender dark strips and minor pyroxene, and blasto-amygdaloid filled with pyrite, chlorite, magnetite, etc.; （ ⅲ ） the results of the petrochemical diagrams show that they are orthometamorphites; （ Ⅳ ） Sm-Nd isotopic age of them is 1 824 Ma (model age (t<sub>DM</sub>) is 2 006—2 132 Ma).展开更多
A series of Cenozoic potassium-rich volcanic rocks developed in the Xiaoguli-Keluo-Wudalianchi-Erkeshan districts,northeast China.The source region and potassium-rich mechanism of the potassic rocks remain highly disp...A series of Cenozoic potassium-rich volcanic rocks developed in the Xiaoguli-Keluo-Wudalianchi-Erkeshan districts,northeast China.The source region and potassium-rich mechanism of the potassic rocks remain highly disputed.In this paper,the major elements,trace elements,and Sr-Nd-Pb isotopes of the volcanic rocks in Keluo(KL)and Wudalianchi(WDLC)volcanic districts were analyzed systematically.The results show that the volcanic rocks are characterized by high K2O(4.36wt.%-6.13wt.%),remarkable enrichment in LREEs and LILEs,as well as the strong fractionation of HREEs.The isotopic characteristics with high 87Sr/86Sr(0.704990-0.705272),low 143Nd/144Nd(0.512306-0.512417),low 206Pb/204Pb(16.546-17.135)and 207Pb/204Pb(15.002-15.783)of the volcanic rocks suggest the involvement of EM-I-type mantle.On the basis of the geochemical characteristics,the potassium-rich volcanic magma originated from the new SCLM forming after delamination of the ancient SCLM,with metasomatism of the potassium-rich fluids released from the ancient lower crust during the Late Mesozoic.The proposed genetic model assumes the source which represented by a phlogopite-bearing garnet peridotite(with modal garnet in the range of 2%-10%)experienced very low degrees(i.e.,~0.5)of partial melting.During Cenozoic,the lithosphere in northeast China was affected by the extension and decompression of continental rift,and the metasomatized SCLM underwent low degree partial melting,resulting in the formation of potassium-rich primitive basaltic magma.展开更多
The Chang＇an gold ore deposit in western Yunnan is located at the southern segment of the Ailaoshan metallogenic belt.The ore bodies are preserved in fractured Ordovician sedimentary clastic rocks.The gold-bearing mi...The Chang＇an gold ore deposit in western Yunnan is located at the southern segment of the Ailaoshan metallogenic belt.The ore bodies are preserved in fractured Ordovician sedimentary clastic rocks.The gold-bearing minerals occur dominantly in sulfide-quartz veins.Fluid inclusion analysis shows that the Chang＇an gold ore deposit is characterized by epithermal gold mineralization at temperatures between 200℃and 280℃at a shallow crustal level.The mineralizing fluids have intermediate to low salinity（6%-18%） and low densities（0.72-1.27 g/cm^3）.The ore minerals haveδ^（34）S in a range from -13‰to 3.57‰,concentrated from -2.06‰to 3.57‰with an average of 1.55‰.The ^（206）Pb/^（204）Pb,^（207）Pb/^（204）Pb and ^（208）Pb/^（204）Pb values are 18.9977-19.5748,15.7093-15.784,39.3814-40.2004 respectively.These isotope data suggest that the ore-forming elements were mainly derived from mixed crustal and mantle sources.The Chang＇an gold ore deposit and Tongchang Cu-Mo deposit are closely related to each other in their spatial distribution and age of formation.They have similar sources of mineralizing elements and identical ore-forming metal elements,and show a close relationship in physical and chemical conditions of mineralization.The two deposits constitute an epithermal-porphyry -skarn type Cu-Mo-Au mineralization system in the Tongchang-Chang＇an area,which is related to the Cenozoic high-K alkaline magmatism.展开更多
The karst mountain areas of Southwest China contain barren farmland soils and suffer from nutritional and water deficiencies that affect crop productivity. Hence,it is imperative to apply suitable fertilizers to resto...The karst mountain areas of Southwest China contain barren farmland soils and suffer from nutritional and water deficiencies that affect crop productivity. Hence,it is imperative to apply suitable fertilizers to restore soil fertility and maintain crop yield. The aim of this study is to investigate the effects of mineral-organic fertilizer(MOF)made of potassic rock and organic waste on the growth of crops. For this purpose, green Chinese cabbage grown using three different fertilization methods including MOF,inorganic fertilizer(IF), and a control was evaluated. We determined soil water content, agronomic characteristics,and biomass of green Chinese cabbage in different treatments. Furthermore, surface runoff from the pot experiments and soil leachate from pot experiments were collected to determine water temperature, pH, and cation and anion concentrations. The results demonstrate thatMOF can improve the soil water-holding capacity of soil,and the basic agronomic characteristics of the cabbage treated with MOF were superior to those with IF. Using MOF can promote the increase in cabbage biomass.Additionally, the concentration of inorganic carbon(largely in the form of HCO_3^-) in surface runoff water treated by MOF was higher than the other treatments, establishing carbon sequestration potential. This work provides a novel and environmentally friendly fertilization pattern in karst areas, which will improve crop yield and also increase the carbon sequestration potential of crops.展开更多
The mineralogical, petrological and geochemical studies on Keliyang （克里阳） potassic dykes have been carried out to understand their rock types, the petrogenesis and the nature of their mantle sources. They arc pot...The mineralogical, petrological and geochemical studies on Keliyang （克里阳） potassic dykes have been carried out to understand their rock types, the petrogenesis and the nature of their mantle sources. They arc potassic lamprophyre, not lamproites as the previous researchers believed. In this study, the whole-rock major and trace element compositions of another 6 lamproite dykes recently discovered are reported. Major elements were determined by X-ray fluorescence spectrometry （XRF） techniques, while REE and trace elements were determined by inductively coupled plasma mass spectrometry （ICP-MS）. They can be classified into phlogopite-diopside lamprophyre, leucite-diopside lamprophyre and granular carbonatite-bearing diopside lamprophyre on the basis of their mineral components. They are all characterized by relatively low SiO2 （41.31% --44. 84% ）, TIO2 （0.75%-0.86% ） and high MgO （7.30%-11.33%）, K2O （4.01%-6.01%） concentrations with K2O/Na2O ratios of 2.77-12.49. In addition, they display enrichment in large-ion lithophile elements （LILEs, e. g., Rb, Sr, Ba） and LREE, but a relative depletion in high-field-strength elements （HFSEs, e.g. , Nb, Ta, Zr, Hf and Ti）. They display similar chondrite-normalized REE patterns with slight negative Eu anomalies （δEu=0.64-0.82）, and high initial ^87 Sr/^86Sr ratios, which resemble those of high K/Ti and Iow-Ti potassic magmas formed in subduction-related settings. Consequently, we suggest that the parental magma was generated by partial melting of the phlogopite-amphibole-bearing garnet lherzolite within the lithospheric mantle that might have been metasomatized by a potassium-bearing fluid released from a sabdaction oceanic crust.展开更多
基金This study was financially supported by the National Natural Science Foundation of China （Grant Nos. 40412012035 and 40511140503）.
文摘Paleoproterozoic potassic granitoids in the southern Sushui Complex from the Zhongtiao Mountains yielded SHRIMP zircon U-Pb ages of 1968-1944 Ma. Lithologically, the potassic granitoid series consists chiefly of monzodiorite, quartz monzonite and syenogranite. Their trace elements and Sm-Nd isotope characteristics indicate that they were derived from partial melting of Archean TTG rocks in an overthickened continental crust. Petrogenesis of this potassic granitoid series implies a collisional environment within the Trans-North China Orogen in the Paleoproterozoic, which supports a tectonic model of Eastern and Western Continental Blocks being amalgamated in the Paleoproterozoic.
文摘The Nangqên basin is one of the Tertiary pull-apart basins situated in the east of the Qiangtang block. Similar to the adjacent Dengqên basin and Baxoi basin, there occurred a series of potassic volcanic and sub-volcanic rocks, ranging from basic, intermediate to intermediate-acid in lithology.
文摘The geochemical characteristics of the Cenozoic volcanic rocks from the north Pulu, east Pulu and Dahongliutan regions in the west Kunlun Mountains are somewhat similar as a whole. However, the volcanic rocks from the Dahongliutan region in the south belt are geochemically distinguished from those in the Pulu region (including the north and east Pulu) of the north belt. The volcanic rocks of the Dahongliutan region are characterized by relatively low TiO2 abundance, but more enrichment in alkali, much more enrichment in light rare earth elements and large ion lithosphile elements than those from the Pulu region. Compared with the Pulu region, volcanic rocks from the Dahongliutan region have relatively low 87Sr/86Sr ratios, and high εNd, 207Pb/204Pb and 208Pb/204Pb. Their trace elements and isotopic data suggest that they were derived from lithospheric mantle, consisting of biotite- and hornblende-bearing garnet lherzolite, which had undertaken metasomatism and enrichment. On the primitive mantle-normalized patterns, they display remarkably negative Nb and Ta anomalies, indicating the presence of early-stage subducted oceanic crust. The metasomatism and enrichment resulted from the fluid released from the crustal materials enclosed in the source region in response to the uplift of asthenospheric mantle. Based on the previous experiments it can be inferred that the thickness of the lithosphere ranges from 75 to 100 km prior to the generation of the magmas. However, the south belt differs from the north one by its thicker lithosphere and lower degree of partial melting. The different thickness of the lithosphere gives rise to corresponding variation of the degree of crustal contamination. The volcanic rocks in the south belt are much more influenced by crustal contamination. In view of the tectonic setting, the generation of potassic magmas is linked with the uplift of asthenosphere resulted from large-scale thinning of the lithosphere after the collision of Indian and Eurasian plates, whereas the thinning of the lithosphere may result from delamination. The potassic magmas mainly resulted from partial melting of lithosphere mantle caused by the uplift of asthenosphere.
基金supported by the Ministry of Science and Technology of China (No 2014DFR21270)China Geological Survey (Nos. DD20160023-01, DD20160022-01)the National Natural Science Foundation of China (Nos. 41720104009, 41672063, 41773029)
文摘Post-collisional potassic and ultrapotassic volcanic rocks are widely distributed across the Tibetan Plateau, and they are considered to be indicators of evolving mantle dynamics. A suite of potassic basalts younger than 55 Ma from the Saga area of western Tibet has been reported. The geochemical characteristics of these rocks distinguish themselves from other potassicltrapotassic volcanic rocks in Tibet, such as positive Nb, Ta, and Ti anomalies and strong enrichment in large ion lithophile elements (LILE), suggesting that phlogopite, rutile and/or sphene might have originated from the mantle source. These basalts are also characterized by a very wide range of 87Sr/86Sr ratios (0.709 043-0.711 915) and relatively high 143Nd/,44Nd ratios (0.512 426-0.512 470,εNd=-4.60 to -3.87). We propose a petrogenetic model for the Saga potassic rocks in which the lithospheric mantle source was infiltrated by a volatilerich (H2O, CO2) and low-degree silicate melt derived from the asthenosphere in the Middle to Late Proterozoic. After the initial Indo-Asian collision, Neo-Tethyan slab breakoff resulted in the partial melting of the previously metasomatized lithospheric mantle and the formation of the Saga potassic rocks. It is likely that the eruption of these volcanic rocks lasted at least 10 Ma.
文摘A novel 3D coordination compound of K（H2TDA）（H20） （1） （H3TDA = 1H-1,2,3-triazole-4,5-dicarboxylic acid） has been prepared and characterized by IR spectroscopy, elemental analysis, ICP and single-crystal X-ray diffraction. Compound 1 displays strong fluorescent emission at room temperature.
基金financially supported by the National Key Research and Development Program of China(Nos.2018YFC0603702,2017YFC0601301)the Open Fund from Sino Probe Laboratory(No.Sinoprobe Lab 202223)+2 种基金the National Natural Science Foundation of China(Nos.92162322,41372077,and U1403291)China Geological Survey(Nos.DD20190685,DD20160024,DD20160123,and DD20160345)IGCP Project 662。
文摘The North China Craton(NCC)is one of the most complex cratons in the world.It underwent a series of tectonothermal events during the Neoarchean-Paleoproterozoic.The petrogenesis of potassic granitoids,the timing,and the style of Archean crustal growth are still debated.Systematic field and petrological stdudies on the potassic meta-granites from the Guyang-Chayouzhongqi region were carried out.New U-Pb ages,zircon Lu-Hf isotopic analyses,and whole-rock geochemical data were obtained.Two groups(~2.7 Ga and~2.5 Ga)of potassic meta-granites were recognized.The~2.7 Ga meta-granites are mainly A2-type,with variableεHf(t)values(-8.4 to+3.3)and Archean one stage model ages(T_(DM)=~3.0 Ga),indicating that their source was derived from ancient anatectic TTG-like granite and depleted mantle,which suggests that thin crust had formed in the Guyang-Chayouzhongqi region by~3.0 Ga.Similar to the K-rich granites in the NCC,most of the~2.5 Ga potassic meta-granites are typical of A1-type granite,and are enriched in Sm and Gd and depleted in Nb,Ta,P,and Ti.The ages and isotopic data indicate that the~2.5 Ga meta-granites were generated from juvenile crustal sources with Neoarchean TTGs.The overall zircon U-Pb and Hf isotopic data furthermore suggested that the~2.7 Ga event is the most important stage of magmatic accretion in the NCC,similar to other cratons.In contrast,reworking or metamorphic alteration was the main crustal process in the NCC at~2.5 Ga.
基金the funds from China Geological Survey Project(12120113087700)Fundamental Research Funds for the Central Universities(2652014017)
文摘1 Introduction Songxian at East Qinling mountains in China possesses more than 100 million tons potassic syenite with the average K2O content of 13%and the main mineral phase of K-feldspar which is a kind of potential potassium
文摘The medium- to coarse-grained and porphyritic granitoid of Dharmawaram, Karimnagar district, Andhra Pradesh, south India is a biotite-hornblende granite with notable contents of rare metal (Zr, Hf, Th) and rare earth (including Y) minerals like zircon, thorite, allanite, monazite and xenotime. Chemically, it is metaluminous (average A/ C+N+K = 0.95)-type, potassic (av. 5% K2O) granite, with dominantly sub-alkaline characters. It shows up to 8 times enrichment of rare metals (Zr, Hf, U, Th) and rare earths (including Y, Sc), with reference to their abundances in normal unevolved granite, and hence, fertile for some of these elements. Field, petrological, geochemical and isotopic data of potassic granite (PG) indicate involvement of silica-rich metasedimentary-basic crustal rocks (amphibole-quartzite, amphibolite, hornblende-biotite gneiss, etc.) in its genesis, at a depth range of 30 km. Further, chondrite-normalized REE patterns demonstrate that low-degree partial melting of source rocks is the major controlling factor in the genesis of PG Mild negative Eu-anomaly (av. Eu/Eu* = 0.48), plots of Ba-Rb-Sr in the field of anomalous granite and K/Rb ratios (av. 239) in the range that is shown by normal unevolved granite together indicate less fractionated nature of the PG Limited fractionation of metalumination-type, involving hornblende, led to occasional weak alumina saturation. Interestingly, geochemical and petrogenetic features of the studied PG broadly match with those potassic granites which are already known to host anomalously high enrichment of rare metals and rare earths in other parts of Andhra Pradesh and adjoining Karnataka.
基金funded by the the Natural Science Foundation of China (No.40672043 to Li Ni)
文摘This study used trace elements in olivine as a new petrogenetic indicator to further constrain the petrogenesis of potassic basalts from the Erkeshan-Wudalianchi-Keluo-Xiaogulihe potassic volcanic field （EWKX for short） in the Songliao Basin of NE China,with a combination of the previous olivine and whole-rock geochemical data.
文摘Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Owing to the limited arable land in China, a vital measure to feed the country’s increasing population is the augmentation of fertilizers so as to gain higher per unit area grain yields. At present, for a fairly long time to come, additional fertilizer resources will mainly come from nitrogen, phosphorus and potassium fertilizers. But there is a severe application disproportion between nitroge-
文摘The Neoproterozoic quartz potassic syenite of the Iwo area,Southwestern Nigeria has been investigated for its magmatic history and zircon saturation temperature.The zircon morphology showed irregular shapes with sectoral and oscillatory micro zoning.The majority of the zircon grains have embayment,which corresponds to magmatic resorption.The syenite crystallized from probably multiple recharge of less evolved magma.Both the magma injection and subsequent crystallization of the rock occurred over a length of time giving the rock some degree of protracted thermal history and slight fluctuation in chemistry,which are manifested as zonation in the analyzed zircon grains.The initial stage of zircon crystallization was marked by a lower cerium anomaly than the final stage,which indicates changes from lower oxidizing to higher oxidizing conditions.The protracted history does not affect the europium anomalies at any stage of crystallization.An average zircon saturation temperature of 865℃estimated from titanium in zircon(T_(Tiz)℃)thermometer using titanium activity of 0.7(^(a)TiO_(2)~0.7)is taken as reasonable crystallization temperature of the rock.This is fairly consistent with 877℃deduced from the zircon solubility model.The titanium in zircon temperature of 910℃at aTiO_(2)~1 is rather too high to be a useful estimate.Both the temperatures 865 and 877℃are however consistent with those of intermediate rocks.The size of the syenite and protracted crystallization history would have made the temperature to have impacted the metamorphic envelope around the syenite.
基金The authors would like to extend their gratitude to the National Natural Science Foundation of Chinathe National Natural Science Foundation of China(Grant No.40172040)+1 种基金 the National Natural Science Foundation of China(Grant No.40234051) the State Key BasisResearchDevelopment Plan ofChina(Grant No.G1999043215).
文摘It is revealed that the protolith of gray-light brown potash-feldspar-leucogranulites and granulites in the 2nd formation of the LG in Tanyaokou deposit are quartz kerotophyre of synsedimentary eruption based on the following facts and features: (1) The rocks look compact and homogeneous without obvious crystals with naked eyes; (2) they contain blastoporphyritic or glomeroporphyritic and blasto-crystalloclastic crystals consisting of quartz with wavy extinction and albite with obvious alteration and deformation; (3) they also contain radiated and fibrous blasto-microspherulitic texture and swallow-tailed bifurcate and blasto-hollow-skeleton crystal texture, representing the rapid cooling characteristic of the magma during submarine volcanic eruption; (4) the major chemical compositions of the rocks are: SiO2 = 70.80%―76.00%, K2O (4.83%―6.22%)>Na2O(2.78%―3.80%), and K2O+Na2O = 8.63%―9.00%; and (5) their petro-chemical diagrams indicate that they are volcanic rocks. Together with the characteristic that they occur in the same sequence with potassic spilite (SiO2 = 46.12%―50.68%, K2O = 4.23%―5.93%>Na2O = 2.15%―3.14%, K2O+Na2O = 6.51%―8.08%), it can be confirmed that the vol-canics occurring in the 2nd Formation of the LG in Tanyaokou district are double-peaking potas-sic volcanic rocks. The discovery, together with the tuffs with ore minerals and the distribution of lead isotopic as well as the value of Co/Ni of pyrites >1 showing the obvious endogenic metali-zation, can prove that the Tanyaokou deposit is an untypical SEDEX-type deposit formed in the extension fault basin in the Mesoproterozonic aulacogen of the northern margin of the North China Platform, and its metallogenesis is related to the synsedimentary volcanic activities and the hydrothermal exhalation, and both the ore-forming material source and volcanics came from mantle or lower crust. These facts mentioned above, together with the meta-volcanic rocks (double-peaking) found in the Dongshengmiao and Huogeqi districts and the host stratigraphic sequence of LG, can further prove that the Mesoproterozoic aulacogen of passive continental margin of Langshan-Zhaertaishan area had been unevenly expanded. This provides some in-formation and new approaches for the study on tectonic-hydrothermal events in Lang-shan-Zhaertaishan aulacogen and their evolutionary process, hydrothermal dynamical source, the relationship between the volcanic activities and the ore-forming process, the regional ore-forming regularity as well as for the correlation with the similar deposits abroad.
文摘It is believed that the albite-potash-feldspar-greenschists in the middle Proterozoic Langshan Group in Tanyaokou District are synsedimentary potassic spilite （or poenite） based on the following facts and features: （ ⅰ ） they occur in beds and look blackish （or apple） green and compact; （ ⅱ ） they bear blasto-glomeroporphyritic and blastocrystalloclastic crystals which consist of （altered） albite laths with hollow skeleton crystal texture in which there are slender dark strips and minor pyroxene, and blasto-amygdaloid filled with pyrite, chlorite, magnetite, etc.; （ ⅲ ） the results of the petrochemical diagrams show that they are orthometamorphites; （ Ⅳ ） Sm-Nd isotopic age of them is 1 824 Ma (model age (t<sub>DM</sub>) is 2 006—2 132 Ma).
基金supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2021QNLM020001-1)Natural Science Foundation of Shandong Province(No.ZR2021MD083)+1 种基金National Natural Science Foundation of China(Grant Nos.41302102 and 41772190)Graduate Innovation Project of China University of Petroleum(East China)(No.YCX2021020).
文摘A series of Cenozoic potassium-rich volcanic rocks developed in the Xiaoguli-Keluo-Wudalianchi-Erkeshan districts,northeast China.The source region and potassium-rich mechanism of the potassic rocks remain highly disputed.In this paper,the major elements,trace elements,and Sr-Nd-Pb isotopes of the volcanic rocks in Keluo(KL)and Wudalianchi(WDLC)volcanic districts were analyzed systematically.The results show that the volcanic rocks are characterized by high K2O(4.36wt.%-6.13wt.%),remarkable enrichment in LREEs and LILEs,as well as the strong fractionation of HREEs.The isotopic characteristics with high 87Sr/86Sr(0.704990-0.705272),low 143Nd/144Nd(0.512306-0.512417),low 206Pb/204Pb(16.546-17.135)and 207Pb/204Pb(15.002-15.783)of the volcanic rocks suggest the involvement of EM-I-type mantle.On the basis of the geochemical characteristics,the potassium-rich volcanic magma originated from the new SCLM forming after delamination of the ancient SCLM,with metasomatism of the potassium-rich fluids released from the ancient lower crust during the Late Mesozoic.The proposed genetic model assumes the source which represented by a phlogopite-bearing garnet peridotite(with modal garnet in the range of 2%-10%)experienced very low degrees(i.e.,~0.5)of partial melting.During Cenozoic,the lithosphere in northeast China was affected by the extension and decompression of continental rift,and the metasomatized SCLM underwent low degree partial melting,resulting in the formation of potassium-rich primitive basaltic magma.
基金supported by the National Key Basic Research and Development(973)Project (2009CB421001)China Geological Survey (1212010661311)+1 种基金Ministry of Land and Resources (200811008)the Ministry of Education,Project 111 (B07011)
文摘The Chang＇an gold ore deposit in western Yunnan is located at the southern segment of the Ailaoshan metallogenic belt.The ore bodies are preserved in fractured Ordovician sedimentary clastic rocks.The gold-bearing minerals occur dominantly in sulfide-quartz veins.Fluid inclusion analysis shows that the Chang＇an gold ore deposit is characterized by epithermal gold mineralization at temperatures between 200℃and 280℃at a shallow crustal level.The mineralizing fluids have intermediate to low salinity（6%-18%） and low densities（0.72-1.27 g/cm^3）.The ore minerals haveδ^（34）S in a range from -13‰to 3.57‰,concentrated from -2.06‰to 3.57‰with an average of 1.55‰.The ^（206）Pb/^（204）Pb,^（207）Pb/^（204）Pb and ^（208）Pb/^（204）Pb values are 18.9977-19.5748,15.7093-15.784,39.3814-40.2004 respectively.These isotope data suggest that the ore-forming elements were mainly derived from mixed crustal and mantle sources.The Chang＇an gold ore deposit and Tongchang Cu-Mo deposit are closely related to each other in their spatial distribution and age of formation.They have similar sources of mineralizing elements and identical ore-forming metal elements,and show a close relationship in physical and chemical conditions of mineralization.The two deposits constitute an epithermal-porphyry -skarn type Cu-Mo-Au mineralization system in the Tongchang-Chang＇an area,which is related to the Cenozoic high-K alkaline magmatism.
基金supported by the National Natural Science Foundation of China (Grant No. 41373078)the National Key Basic Research Program of China (Grant No. 2013CB956702)
文摘The karst mountain areas of Southwest China contain barren farmland soils and suffer from nutritional and water deficiencies that affect crop productivity. Hence,it is imperative to apply suitable fertilizers to restore soil fertility and maintain crop yield. The aim of this study is to investigate the effects of mineral-organic fertilizer(MOF)made of potassic rock and organic waste on the growth of crops. For this purpose, green Chinese cabbage grown using three different fertilization methods including MOF,inorganic fertilizer(IF), and a control was evaluated. We determined soil water content, agronomic characteristics,and biomass of green Chinese cabbage in different treatments. Furthermore, surface runoff from the pot experiments and soil leachate from pot experiments were collected to determine water temperature, pH, and cation and anion concentrations. The results demonstrate thatMOF can improve the soil water-holding capacity of soil,and the basic agronomic characteristics of the cabbage treated with MOF were superior to those with IF. Using MOF can promote the increase in cabbage biomass.Additionally, the concentration of inorganic carbon(largely in the form of HCO_3^-) in surface runoff water treated by MOF was higher than the other treatments, establishing carbon sequestration potential. This work provides a novel and environmentally friendly fertilization pattern in karst areas, which will improve crop yield and also increase the carbon sequestration potential of crops.
基金This paper is supported by the National Natural Science Foundationof China (No .40072061) the Programfor New Century ExcellentTalents in University (No. NCET-04-0728) the Fund of the K-ey Subject on Mineral Prospecting and Exploration Ⅰin Xinjiang .
文摘The mineralogical, petrological and geochemical studies on Keliyang （克里阳） potassic dykes have been carried out to understand their rock types, the petrogenesis and the nature of their mantle sources. They arc potassic lamprophyre, not lamproites as the previous researchers believed. In this study, the whole-rock major and trace element compositions of another 6 lamproite dykes recently discovered are reported. Major elements were determined by X-ray fluorescence spectrometry （XRF） techniques, while REE and trace elements were determined by inductively coupled plasma mass spectrometry （ICP-MS）. They can be classified into phlogopite-diopside lamprophyre, leucite-diopside lamprophyre and granular carbonatite-bearing diopside lamprophyre on the basis of their mineral components. They are all characterized by relatively low SiO2 （41.31% --44. 84% ）, TIO2 （0.75%-0.86% ） and high MgO （7.30%-11.33%）, K2O （4.01%-6.01%） concentrations with K2O/Na2O ratios of 2.77-12.49. In addition, they display enrichment in large-ion lithophile elements （LILEs, e. g., Rb, Sr, Ba） and LREE, but a relative depletion in high-field-strength elements （HFSEs, e.g. , Nb, Ta, Zr, Hf and Ti）. They display similar chondrite-normalized REE patterns with slight negative Eu anomalies （δEu=0.64-0.82）, and high initial ^87 Sr/^86Sr ratios, which resemble those of high K/Ti and Iow-Ti potassic magmas formed in subduction-related settings. Consequently, we suggest that the parental magma was generated by partial melting of the phlogopite-amphibole-bearing garnet lherzolite within the lithospheric mantle that might have been metasomatized by a potassium-bearing fluid released from a sabdaction oceanic crust.
