Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques w...Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques were contrast stretching, density slicing, spatial filtering, Fourier analysis, brightness inversion, band combinations, and band ratioing. It has been revealed that, owing to the presence of gossans at Paishanlou, the mixture of iron oxide and clay minerals affects the spectral reflectance in satellite data. The mineral and hydrothermal composite images with band ratios 5/7+5/4+3/1 RGB and 5/7+3/1+4/3 RGB, respectively, yielded the best results for their sensitivity to lithologic variables, and lack of statistical redundancy. Ratio 3/1 clearly highlighted ferric (Fe 3+ ) iron; 5/4 depicted ferrous (Fe 2+ ) iron, and 5/7 depicted clays, carbonates, and hydroxyl bearing minerals. Vegetation was also successfully discriminated by ratio 5/7. Finally, coupled with field surveys, petrographical and geochemical data, the observed anomalies led to the discovery of three new sites, which are gold mineralized. The prime objective of this study was to map supergene and/or hypogene signatures in the gold mineralized areas using Landsat ETM+ data at Paishanlou.展开更多
Original sedimentary manganese(Mn)deposits and supergene Mn ores are important Mn resources in China.However,the geochemical information from Chinese supergene Mn ores is scarce,and the relationship between sedimentar...Original sedimentary manganese(Mn)deposits and supergene Mn ores are important Mn resources in China.However,the geochemical information from Chinese supergene Mn ores is scarce,and the relationship between sedimentary Mn deposits and supergene Mn ores is ambiguous.In this study,we collected the original Mn-bearing dolomitic sandstones(ZK20-3 drillcore)and supergene Mn ores(Longmen Section)from eastern Hebei,North China for systematic petrographic,mineralogical and geochemical analyses.Our new data help us to figure out the transformation from original Mn-bearing deposits to supergene ores.The main minerals of original Mn-bearing dolomitic sandstones are quartz and feldspar,with minor muscovite,dolomite,rhodochrosite,ankerite,and kutnohorite.Supergene Mn-oxide ores only emerged in the middle part of the Longmen(LM)Section,and mainly contain quartz,pyrolusite,cryptomelane,todorokite and occasional dolomite.The possible transformation sequence of Mn minerals is:kutnohorite/rhodochrosite→pyrolusite(Ⅰ)→cryptomelane(todorokite)→todorokite(cryptomelane)→pyrolusite(Ⅱ).For Mn-oxide ores,Fe,Na and Si are enriched but Al,Ca,Mg and K are depleted with the enrichment of Mn.For original and supergene ores,the total rare earth element+ytterbium(∑REY)contents range from 105.68×10^(-6)to 250.56×10^(-6)and from 18.08×10^(-6)to 176.60×10^(-6),respectively.Original Mn ores have similar slightly LREE-enriched patterns,but the purer Mn-oxide ore shows a HREE-enriched pattern.In the middle part of the LM Section,positive Ce anomalies in Mn-oxide ores indicate the precipitation of Ce-bearing minerals.It implies the existence of geochemical barriers,which changed p H and Eh values due to the long-time influence of groundwater.展开更多
Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and ...Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and duration of their formation are sparse, mainly due to the difficulties extracting datable minerals suited to traditional radiometric dating methods. Hollandite, cryptomelane, coronadite, todorokite, and manjiroite are common manganese oxide minerals in supergene environments. These minerals host potassium of variable amounts from 0.1 wt% to 5.0 wt% in their structural sites. This geochemical property provides possibility to date supergene manganese ores by using K-Ar and 40Ar/ 39Ar methods. In this study, we perform 40Ar/ 39Ar dating on a 7.1-cm-thick botryoidal manganese nodule from an ancient weathering profile at Mount Tabor, central Queensland, Australia. Laser microprobe incremental analyses of distinct growth bands, from the inner core through the intermediate bands to the outermost crusts of the nodule, have yielded high quality 40Ar/ 39Ar ages at 27.3 Ma, 20.9 Ma, 19.2 Ma, and 16.1 Ma, respectively. The age results permit preliminary estimates on the average growth rates of the nodule varying from 4.7×10 -3 mm/ka to 7.6×10 -3 mm/ka to 9.0×10 -3 mm/ka, from the core to the rim. Results of this study are of significance in our understanding of the mode, mechanism, process, and climatic conditions in the formation of supergene manganese ore deposits.展开更多
The Sain Us gold deposit is a typical auriferous sulphide quartz vein deposit in the InnerMongolian arid steppe climatic region. The oxidation zone has been controlled by the arid cli-mate since the beginning of the H...The Sain Us gold deposit is a typical auriferous sulphide quartz vein deposit in the InnerMongolian arid steppe climatic region. The oxidation zone has been controlled by the arid cli-mate since the beginning of the Holocene. Gold supergene evolution is characterized by enlarge-ment of gold grains, complication of the gold form, raising of the gold grade and increase of thegold fineness; besides, gold and silver have two enrichment peaks at the same depth, which is insharp contrast to the unimodal enrichment of gold and silver and the occurrence of gold aboveand silver below in a humid climatic region. Sun pumping is the main cause for the bimodalenrichment of gold and silver. Illite 2 M_1 is one of the main causes for the upper enrichment peakof gold and silver.展开更多
Objective Using homology primers for clone of β-chemokine receptor supergene-family from lower level RNA expression. Methods: Through similarity alignment of the conservative transmembrane domainof human MCP-l recept...Objective Using homology primers for clone of β-chemokine receptor supergene-family from lower level RNA expression. Methods: Through similarity alignment of the conservative transmembrane domainof human MCP-l receptor, mouse MIP-lα receptor and rat IL-8 receptor. the degenerate oligonucleotide homology primers were designed and a cDNA fragment was amplified by RT--PCR. After a new gene sequenceof chemokine receptor supergene-family in GenBank was identified, the new gene full sequence was cloned bya Marathon PCR of the specific primers. Results: Mouse CCR5 full-length cDNA with 2888 bp was cloned,including open reading frame 1065 oligonucleotides and coding 355 amino acids. This gene was a novel member of the β-chemokine receptor supergene-family confirmed by sequence analysis, ligand binding assay andinforming from GenBank. Conclusion: Using homology primers, the novel member of the supergene-familycan be captured. This method is a new cloning strategy and has extensive significance in the molecular cloningof a new gene.展开更多
Iron isotopes,represented byδ^(56)Fe,serve as valuable tools for constraining the surface iron processes and as potent tracers for studying the biogeochemical cycle of iron.Nevertheless,our comprehension of iron isot...Iron isotopes,represented byδ^(56)Fe,serve as valuable tools for constraining the surface iron processes and as potent tracers for studying the biogeochemical cycle of iron.Nevertheless,our comprehension of iron isotopes in the land surface processes of the Tibetan Plateau(TP)remains limited.In this study,we present the results of iron isotopic composition(δ^(56)Fe)in the surface soils of the TP,encompassing both glacial and non-glacial regions characterized by rugged and flat topographies.Our findings reveal that soilδ^(56)Fe values ranged from-0.01‰±0.05‰to 0.14‰±0.01‰,with the highest values observed in eastern locations(0.14‰)and the lowest appeared in the northeast(-0.1‰).On a global scale,theδ^(56)Fe values observed in Tibetan soils exhibited relatively small variability compared to reservoirs marked by significant iron isotope fractionation.By contrast,the range of TP soils measured here was slightly larger than that of the Chinese Loess.Furthermore,we discerned noticeable spatial variations inδ^(56)Fe across the large-scale region of TP,indicating a gradual increase trend from the northeast to the south and from the west to the east.These regional disparities inδ^(56)Fe likely arise from a combination of constraining factors,including differences in mineralogy,lithological variations,organic matter content,and variations in chemical weathering intensity.This study is pivotal in advancing our understanding of land surface iron isotope dynamics and its role in the biogeochemical cycle within the TP region.展开更多
Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other...Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status. The taxonomic list is followed by brief discussions on the systematics of the species as well as by a few comments concerning the eventual broader zoogeographical and speleological implications of the Ayyalon faunistic findings, as they appeared in literature.展开更多
第一届可持续发电与供电国际会议(the First International Conference on Sustainable Power Generation and Supply, SUPERGEN 2009)将于2009年4月6-7日在中国江苏省南京市举行。本次会议由英中清洁能源研究协作网(UK-China
文摘Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques were contrast stretching, density slicing, spatial filtering, Fourier analysis, brightness inversion, band combinations, and band ratioing. It has been revealed that, owing to the presence of gossans at Paishanlou, the mixture of iron oxide and clay minerals affects the spectral reflectance in satellite data. The mineral and hydrothermal composite images with band ratios 5/7+5/4+3/1 RGB and 5/7+3/1+4/3 RGB, respectively, yielded the best results for their sensitivity to lithologic variables, and lack of statistical redundancy. Ratio 3/1 clearly highlighted ferric (Fe 3+ ) iron; 5/4 depicted ferrous (Fe 2+ ) iron, and 5/7 depicted clays, carbonates, and hydroxyl bearing minerals. Vegetation was also successfully discriminated by ratio 5/7. Finally, coupled with field surveys, petrographical and geochemical data, the observed anomalies led to the discovery of three new sites, which are gold mineralized. The prime objective of this study was to map supergene and/or hypogene signatures in the gold mineralized areas using Landsat ETM+ data at Paishanlou.
基金supported by the National Key R&D Program of China(No.2022YFF0800200)the NSFC(Nos.U1812402 and 42072131)+6 种基金Most Special Fund(No.MSFGPMR33)from the State Key Laboratory of GPMRthe CUG Scholar Scientific Research Funds(No.2022036)the NSF of Hebei Province(No.D2021334001)Research Project of Talent Engineering Training of Hebei Province(No.B2020005007)Research Project of Postdoctoral Scientific Research Station of HBGMR(No.454-0602-YBN-Z9E4)Natural Science Foundation of Hebei Province(No.D2021334001)the Central Government Guides Local Funds for Scientific and Technological Development(No.236Z7608 G)。
文摘Original sedimentary manganese(Mn)deposits and supergene Mn ores are important Mn resources in China.However,the geochemical information from Chinese supergene Mn ores is scarce,and the relationship between sedimentary Mn deposits and supergene Mn ores is ambiguous.In this study,we collected the original Mn-bearing dolomitic sandstones(ZK20-3 drillcore)and supergene Mn ores(Longmen Section)from eastern Hebei,North China for systematic petrographic,mineralogical and geochemical analyses.Our new data help us to figure out the transformation from original Mn-bearing deposits to supergene ores.The main minerals of original Mn-bearing dolomitic sandstones are quartz and feldspar,with minor muscovite,dolomite,rhodochrosite,ankerite,and kutnohorite.Supergene Mn-oxide ores only emerged in the middle part of the Longmen(LM)Section,and mainly contain quartz,pyrolusite,cryptomelane,todorokite and occasional dolomite.The possible transformation sequence of Mn minerals is:kutnohorite/rhodochrosite→pyrolusite(Ⅰ)→cryptomelane(todorokite)→todorokite(cryptomelane)→pyrolusite(Ⅱ).For Mn-oxide ores,Fe,Na and Si are enriched but Al,Ca,Mg and K are depleted with the enrichment of Mn.For original and supergene ores,the total rare earth element+ytterbium(∑REY)contents range from 105.68×10^(-6)to 250.56×10^(-6)and from 18.08×10^(-6)to 176.60×10^(-6),respectively.Original Mn ores have similar slightly LREE-enriched patterns,but the purer Mn-oxide ore shows a HREE-enriched pattern.In the middle part of the LM Section,positive Ce anomalies in Mn-oxide ores indicate the precipitation of Ce-bearing minerals.It implies the existence of geochemical barriers,which changed p H and Eh values due to the long-time influence of groundwater.
文摘Increasing world-class, high-grade, and metals-enriched supergene manganese ore deposits have been discovered in the last two decades, making them more and more economically important. However, data on the timing and duration of their formation are sparse, mainly due to the difficulties extracting datable minerals suited to traditional radiometric dating methods. Hollandite, cryptomelane, coronadite, todorokite, and manjiroite are common manganese oxide minerals in supergene environments. These minerals host potassium of variable amounts from 0.1 wt% to 5.0 wt% in their structural sites. This geochemical property provides possibility to date supergene manganese ores by using K-Ar and 40Ar/ 39Ar methods. In this study, we perform 40Ar/ 39Ar dating on a 7.1-cm-thick botryoidal manganese nodule from an ancient weathering profile at Mount Tabor, central Queensland, Australia. Laser microprobe incremental analyses of distinct growth bands, from the inner core through the intermediate bands to the outermost crusts of the nodule, have yielded high quality 40Ar/ 39Ar ages at 27.3 Ma, 20.9 Ma, 19.2 Ma, and 16.1 Ma, respectively. The age results permit preliminary estimates on the average growth rates of the nodule varying from 4.7×10 -3 mm/ka to 7.6×10 -3 mm/ka to 9.0×10 -3 mm/ka, from the core to the rim. Results of this study are of significance in our understanding of the mode, mechanism, process, and climatic conditions in the formation of supergene manganese ore deposits.
文摘The Sain Us gold deposit is a typical auriferous sulphide quartz vein deposit in the InnerMongolian arid steppe climatic region. The oxidation zone has been controlled by the arid cli-mate since the beginning of the Holocene. Gold supergene evolution is characterized by enlarge-ment of gold grains, complication of the gold form, raising of the gold grade and increase of thegold fineness; besides, gold and silver have two enrichment peaks at the same depth, which is insharp contrast to the unimodal enrichment of gold and silver and the occurrence of gold aboveand silver below in a humid climatic region. Sun pumping is the main cause for the bimodalenrichment of gold and silver. Illite 2 M_1 is one of the main causes for the upper enrichment peakof gold and silver.
文摘Objective Using homology primers for clone of β-chemokine receptor supergene-family from lower level RNA expression. Methods: Through similarity alignment of the conservative transmembrane domainof human MCP-l receptor, mouse MIP-lα receptor and rat IL-8 receptor. the degenerate oligonucleotide homology primers were designed and a cDNA fragment was amplified by RT--PCR. After a new gene sequenceof chemokine receptor supergene-family in GenBank was identified, the new gene full sequence was cloned bya Marathon PCR of the specific primers. Results: Mouse CCR5 full-length cDNA with 2888 bp was cloned,including open reading frame 1065 oligonucleotides and coding 355 amino acids. This gene was a novel member of the β-chemokine receptor supergene-family confirmed by sequence analysis, ligand binding assay andinforming from GenBank. Conclusion: Using homology primers, the novel member of the supergene-familycan be captured. This method is a new cloning strategy and has extensive significance in the molecular cloningof a new gene.
基金supported by the National Natural Science Foundation of China(Nos.42201152,42371139)the Gansu Province Natural Science Foundation Key Project(No.23JRRA858)+2 种基金the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUG240629)the“CUG Scholar”Scientific Research Funds at China University of Geosciences(Wuhan)(No.2023092)EJRP is supported by the German Research Foundation(DFG)through the Heisenberg Programme“Multiscale Simulation of Earth Surface Processes”。
文摘Iron isotopes,represented byδ^(56)Fe,serve as valuable tools for constraining the surface iron processes and as potent tracers for studying the biogeochemical cycle of iron.Nevertheless,our comprehension of iron isotopes in the land surface processes of the Tibetan Plateau(TP)remains limited.In this study,we present the results of iron isotopic composition(δ^(56)Fe)in the surface soils of the TP,encompassing both glacial and non-glacial regions characterized by rugged and flat topographies.Our findings reveal that soilδ^(56)Fe values ranged from-0.01‰±0.05‰to 0.14‰±0.01‰,with the highest values observed in eastern locations(0.14‰)and the lowest appeared in the northeast(-0.1‰).On a global scale,theδ^(56)Fe values observed in Tibetan soils exhibited relatively small variability compared to reservoirs marked by significant iron isotope fractionation.By contrast,the range of TP soils measured here was slightly larger than that of the Chinese Loess.Furthermore,we discerned noticeable spatial variations inδ^(56)Fe across the large-scale region of TP,indicating a gradual increase trend from the northeast to the south and from the west to the east.These regional disparities inδ^(56)Fe likely arise from a combination of constraining factors,including differences in mineralogy,lithological variations,organic matter content,and variations in chemical weathering intensity.This study is pivotal in advancing our understanding of land surface iron isotope dynamics and its role in the biogeochemical cycle within the TP region.
文摘Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status. The taxonomic list is followed by brief discussions on the systematics of the species as well as by a few comments concerning the eventual broader zoogeographical and speleological implications of the Ayyalon faunistic findings, as they appeared in literature.
文摘第一届可持续发电与供电国际会议(the First International Conference on Sustainable Power Generation and Supply, SUPERGEN 2009)将于2009年4月6-7日在中国江苏省南京市举行。本次会议由英中清洁能源研究协作网(UK-China
