A large number of fluid inclusions are formed in the crystal formation of halite,in which pure liquid phase ones supply a new method of paleo temperature inversion by means of cryogenic thermometry.In this study,we
The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that ...The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that can be used to calculate the relative proportion of NaCl(i.e.,NaCl/[NaCl+CaCl_2],or X_(NaCl))and the total salinity( i.e.,NaC1 + CaC12,wt% )for fluid inclusions with ice as the last melting phase.X_(NaCl)can be calculated from T_(m-HH)using the following equation: y=(a+bx)^(-1/c) where y is X_(NaCl),x is T_(m-HH),a=0.33124402,b=-0.031518028,and c=0.22932736.In the cases where only T_(m-ice)is measured and T_(m-HH)is not known,T_(m-ice)can be used as the maximum possible TIn.nil to calculate the maximum value of X_(NaCl)using the above equation.In these cases,the following equation can be used to calculate the maximum total salinity: y=(a+bx+cx^2)^(-1) where y is salinity,x is T_(m-HH),a=0.057184817,b=0.00078565757,and c=5.7262766E-6.Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl_2 binary side in the H20-NaC1-CaC12 ternary system,the errors in salinity calculation introduced by the above approximation are small(less than 2 wt% ).A Windows program for calculation of X_(NsCl)and salinity is available at: http://uregina.ca/~chiguox.展开更多
Common wheat(Triticum aestivum)is one of the most widely cultivated and consumed crops globally.In the face of limited arable land and climate changes,it is a great challenge to maintain current and increase future wh...Common wheat(Triticum aestivum)is one of the most widely cultivated and consumed crops globally.In the face of limited arable land and climate changes,it is a great challenge to maintain current and increase future wheat production.Enhancing agronomic traits in wheat by introducing mutations across all three homoeologous copies of each gene has proven to be a difficult task due to its large genome with high repetition.However,clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associ-ated nuclease(Cas)genome editing technologies offer a powerful means of precisely manipulating the genomes of crop species,thereby opening up new possibilities for biotechnology and breeding.In this review,we first focus on the development and optimization of the current CRISPR-based genome editing tools in wheat,emphasizing recent breakthroughs in precise and multiplex genome editing.We then describe the general procedure of wheat genome editing and highlight different methods to deliver the genome editing reagents into wheat cells.Furthermore,we summarize the recent applications and ad-vancements of CRISPR/Cas technologies for wheat improvement.Lastly,we discuss the remaining chal-lenges specific to wheat genome editing and its future prospects.展开更多
The ore genesis model for the Dachang Sn-polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro-ther...The ore genesis model for the Dachang Sn-polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro-thermal event or they were products of Devonian syn-sedi-mentary exhalative-hydrothermal event. This note presents new helium isotope data from fluid inclusions of four pyrites and one fluorite. The pyrites were collected from the stratiform and massive orebodies in the deposit, and their 3He/4He ratios are significantly higher than 1, ranging from 1.7 to 2.5 Ra, which indicates a mantle component in the responsible hydrothermal fluids. It is suggested that the ore-forming fluids were a mixture of deep circulating seawater and a mantle-derived fluid, which are similar to many of those modern submarine hydrothermal fluids. In contrast, the fluorite, collected from a granite-related hydrothermal vein in the deposit, shows a low 3He/4He ratio of 0.7 Ra, which indicates no mantle component展开更多
Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal g...Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.展开更多
The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively cou...The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively coupled plasma mass spectrometer)trace element geochemistry data for pyrite and sphalerite from different stages in the Qixiashan Deposit are reported,the Pb-Zn mineralization processes are reconstructed,and a genetic model is constructed.Four paragenetic stages of Pb-Zn ore deposition are identified:the biogenic pyrite mineralization stage(Stage 1),the early stage of hydrothermal Pb-Zn mineralization(Stage 2),the late stage of hydrothermal Pb-Zn mineralization(Stage 3),and the carbonate stage(Stage 4).Stages 2 and 3 are the main ore stages.The trace element characteristics of the sulfide in stages 2 and 3,such as the higher Co/Ni and lower trace element contents of the pyrite and the Fe,Mn,and Ge contents of the sphalerite,indicate that they were generated by magmatic-hydrothermal processes.Furthermore,the lower Cu,Ag,Sb,and Pb contents of the pyrite and sphalerite of Stage 3 compared to Stage 2 suggest an increase in magmatic-hydrothermal activity from Stage 2 to Stage 3.The hydrothermal fluids leached trace elements(e.g.,Cu,Ag,Sb,and Pb)from the previously deposited primary pyrite and sphalerite,which were precipitated in the later hydrothermal stage Cu,Au,Ag,Sb,and Pb bearing minerals and secondary pyrite and sphalerite with lower trace element contents(e.g.,Cu,Au,Ag,Sb,and Pb).Compared with the pyrite from stages 2 and 3,the Stage 1 pyrite has relatively higher trace elements contents(Sb,Cu,Zn,Au,Ag,Pb,As,and Ni).However,their lower Co/Ni ratio suggests a syngenetic sedimentary origin.Based on the petrographic features and trace element data,a multi-stage mineralization model is proposed.The Stage 1 biogenic pyrite formed stratiform pyrite layers,which provided reducing conditions and a base for the subsequent Pb-Zn mineralization.During Stage 2,subsequent hydrothermal fluid interacted with the stratiform pyrite layers,which resulted in sulfide precipitation and the formation of stratiform Pb-Zn orebodies.In Stage 3,the hydrothermal fluid replaced the limestone along the fractures,which triggered the formation of Pb-Zn vein orebodies.展开更多
文摘A large number of fluid inclusions are formed in the crystal formation of halite,in which pure liquid phase ones supply a new method of paleo temperature inversion by means of cryogenic thermometry.In this study,we
文摘The composition of fluid inclusions in the H_2O-NaCl-CaCl_2 system has been generally graphically estimated using the melting temperatures of hydrohalite(T_(m-HH))and ice(T_(m-ice)).Here we present two equations that can be used to calculate the relative proportion of NaCl(i.e.,NaCl/[NaCl+CaCl_2],or X_(NaCl))and the total salinity( i.e.,NaC1 + CaC12,wt% )for fluid inclusions with ice as the last melting phase.X_(NaCl)can be calculated from T_(m-HH)using the following equation: y=(a+bx)^(-1/c) where y is X_(NaCl),x is T_(m-HH),a=0.33124402,b=-0.031518028,and c=0.22932736.In the cases where only T_(m-ice)is measured and T_(m-HH)is not known,T_(m-ice)can be used as the maximum possible TIn.nil to calculate the maximum value of X_(NaCl)using the above equation.In these cases,the following equation can be used to calculate the maximum total salinity: y=(a+bx+cx^2)^(-1) where y is salinity,x is T_(m-HH),a=0.057184817,b=0.00078565757,and c=5.7262766E-6.Because the isothems in the field of ice are sub-parallel to the NaCl-CaCl_2 binary side in the H20-NaC1-CaC12 ternary system,the errors in salinity calculation introduced by the above approximation are small(less than 2 wt% ).A Windows program for calculation of X_(NsCl)and salinity is available at: http://uregina.ca/~chiguox.
基金supported by grants from the National Key Research and Development Program of China(No.2021YFF1000800)the Frontiers Science Center for Molecular Design Breeding(No.2022TC152)+1 种基金the Hainan Yazhou Bay Seed Laboratory(No.B21HJ0504)China Agricultural University Start-up Funding.
文摘Common wheat(Triticum aestivum)is one of the most widely cultivated and consumed crops globally.In the face of limited arable land and climate changes,it is a great challenge to maintain current and increase future wheat production.Enhancing agronomic traits in wheat by introducing mutations across all three homoeologous copies of each gene has proven to be a difficult task due to its large genome with high repetition.However,clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associ-ated nuclease(Cas)genome editing technologies offer a powerful means of precisely manipulating the genomes of crop species,thereby opening up new possibilities for biotechnology and breeding.In this review,we first focus on the development and optimization of the current CRISPR-based genome editing tools in wheat,emphasizing recent breakthroughs in precise and multiplex genome editing.We then describe the general procedure of wheat genome editing and highlight different methods to deliver the genome editing reagents into wheat cells.Furthermore,we summarize the recent applications and ad-vancements of CRISPR/Cas technologies for wheat improvement.Lastly,we discuss the remaining chal-lenges specific to wheat genome editing and its future prospects.
基金This work was jointly supported by the National Science Foundation Project for the Outstanding Youth Scientists (Grant No. 49925306)the State Key Basic Research Program of China (Grant No. G1999043211).
文摘The ore genesis model for the Dachang Sn-polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro-thermal event or they were products of Devonian syn-sedi-mentary exhalative-hydrothermal event. This note presents new helium isotope data from fluid inclusions of four pyrites and one fluorite. The pyrites were collected from the stratiform and massive orebodies in the deposit, and their 3He/4He ratios are significantly higher than 1, ranging from 1.7 to 2.5 Ra, which indicates a mantle component in the responsible hydrothermal fluids. It is suggested that the ore-forming fluids were a mixture of deep circulating seawater and a mantle-derived fluid, which are similar to many of those modern submarine hydrothermal fluids. In contrast, the fluorite, collected from a granite-related hydrothermal vein in the deposit, shows a low 3He/4He ratio of 0.7 Ra, which indicates no mantle component
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB18020303)the National Key Basic Research Progam of China (2015CB856100)
文摘Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.
基金This study was supported by the National Natural Science Foundation of China(No.1212011220678)We are very grateful to Jiangsu East China Basic Geological Exploration Co.,Ltd.for providing basic geological data and assistance in the field.
文摘The large-scale Qixiashan Pb-Zn Deposit in the eastern Middle-Lower Yangtze metallogenic belt is hosted in carbonate rocks.Based on a detailed mineral paragenesis study,in-situ LA-ICP-MS(laser ablation inductively coupled plasma mass spectrometer)trace element geochemistry data for pyrite and sphalerite from different stages in the Qixiashan Deposit are reported,the Pb-Zn mineralization processes are reconstructed,and a genetic model is constructed.Four paragenetic stages of Pb-Zn ore deposition are identified:the biogenic pyrite mineralization stage(Stage 1),the early stage of hydrothermal Pb-Zn mineralization(Stage 2),the late stage of hydrothermal Pb-Zn mineralization(Stage 3),and the carbonate stage(Stage 4).Stages 2 and 3 are the main ore stages.The trace element characteristics of the sulfide in stages 2 and 3,such as the higher Co/Ni and lower trace element contents of the pyrite and the Fe,Mn,and Ge contents of the sphalerite,indicate that they were generated by magmatic-hydrothermal processes.Furthermore,the lower Cu,Ag,Sb,and Pb contents of the pyrite and sphalerite of Stage 3 compared to Stage 2 suggest an increase in magmatic-hydrothermal activity from Stage 2 to Stage 3.The hydrothermal fluids leached trace elements(e.g.,Cu,Ag,Sb,and Pb)from the previously deposited primary pyrite and sphalerite,which were precipitated in the later hydrothermal stage Cu,Au,Ag,Sb,and Pb bearing minerals and secondary pyrite and sphalerite with lower trace element contents(e.g.,Cu,Au,Ag,Sb,and Pb).Compared with the pyrite from stages 2 and 3,the Stage 1 pyrite has relatively higher trace elements contents(Sb,Cu,Zn,Au,Ag,Pb,As,and Ni).However,their lower Co/Ni ratio suggests a syngenetic sedimentary origin.Based on the petrographic features and trace element data,a multi-stage mineralization model is proposed.The Stage 1 biogenic pyrite formed stratiform pyrite layers,which provided reducing conditions and a base for the subsequent Pb-Zn mineralization.During Stage 2,subsequent hydrothermal fluid interacted with the stratiform pyrite layers,which resulted in sulfide precipitation and the formation of stratiform Pb-Zn orebodies.In Stage 3,the hydrothermal fluid replaced the limestone along the fractures,which triggered the formation of Pb-Zn vein orebodies.
