Mississippi-Valley＇s carbonate-type （MVT） lead-zinc deposits are the most important type of lead-zinc deposits in the southwest of China. In 2013, China Geological Survey Bureau deployed a project named ＂Experimen...Mississippi-Valley＇s carbonate-type （MVT） lead-zinc deposits are the most important type of lead-zinc deposits in the southwest of China. In 2013, China Geological Survey Bureau deployed a project named ＂Experimental Investigation of Integrated Prospecting Technology for Concealed Carbonate-Type Lead-Zinc Deposits in the Region of Sichuan, Yunnan and Guizhou Provinces＂. This project has been implemented by the Chengdu Center of China Geological Survey since 2013, and the project has run for 3 years. The general objective of this project is to establish an effective and adaptable integrated prospecting methodology （including geological, geophysical and geochemical techniques） in search for deep concealed lead-zinc deposits.展开更多
Most of the lead and zinc deposits in Southwest China, are characterized by mineral zoning, which is especially true for the Huize and Zhaotong deposits. The mineral assemblage zoning is consistent for both horizontal...Most of the lead and zinc deposits in Southwest China, are characterized by mineral zoning, which is especially true for the Huize and Zhaotong deposits. The mineral assemblage zoning is consistent for both horizontal and vertical zoning, from the base(center) of the ore body to the top(outermost), the mineral zones are as follows. I-1: coarse-grained pyrite and a little puce sphalerite;I-2: brown sphalerite, galena, and ferro-dolomite;I-3: galena, sandy beige and pale yellow sphalerite, and calcite;and I-4: fine-grained pyrite, dolomite, and calcite. Among them, sphalerite is the landmark mineral of different zoning. From I-1 to I-3, the color of sphalerite changes from dark to light, its crystalline size changes from coarse to fine, and its structure changes from disseminated to veinlet. This mineral zoning is seen not only on a microscopic scale, but is also clear on a mesoscopic and macroscopic scale. It is caused by the order of the sphalerite and galena precipitation. We studied the metallic minerals and fluid inclusions using a thermodynamic phase diagram method, such as lgfO2–lgfS2, pH–lgfO2, pH–lg[Pb^2+] and pH–lg[HS^-], discussed the constraints on the order of the sphalerite and galena precipitation in the migration and precipitation process of lead and zinc under different pH values, oxygen fugacity, sulfur fugacity, and ionic activity. We also explain the formation mechanism and propose that the main controlling factor of the order of the sphalerite and galena precipitation is sulfur fugacity.展开更多
An attempt is made in this paper to describe the following laws governing the distribution of lead-zinc deposits in China: spatial distribution laws, temporal distribution laws, deep level control laws, and deposits a...An attempt is made in this paper to describe the following laws governing the distribution of lead-zinc deposits in China: spatial distribution laws, temporal distribution laws, deep level control laws, and deposits association and zoning laws.展开更多
Qinling-type Pb-Zn deposits are located in the Qinling fold belt, occurring in the fine-clastic and carbonate rocks of the Devonian marine facies. They are reformed sedimentary deposits originating from hydrothermal w...Qinling-type Pb-Zn deposits are located in the Qinling fold belt, occurring in the fine-clastic and carbonate rocks of the Devonian marine facies. They are reformed sedimentary deposits originating from hydrothermal waters, and may be subdivided into 2 subtypes: hydrothermal sedimentary deposits (Changba subtype) and reformed hydrothermal sedimentary deposits (Bijiashan-Qiandongshan subtype). In comparison with some of the famous Palaeozoic Pb-Zn deposits in the world, the Qinling-type Pb-Zn deposits constitute an independent type, which possesses some characteristics of both hydrothermal sedimentary deposits (Meggen type) and reformed hydrothermal deposits (Mississippi Valley type).展开更多
Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary...Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary tumor.By definition,no residual lymph node structure should be identified in these tumor masses.At present,TDs are mainly reported in colorectal cancer,with a few reports in gastric cancer.There are very few reports on breast cancer(BC).For TDs,current dominant theories suggest that these are the result of lymph node metastasis of the tumor with complete destruction of the lymph nodes by the tumor tissue.Even some pathologists classify a TD as two lymph node metastases for calculation.Some pathologists also believe that TDs belong to the category of disseminated metastasis.Therefore,regardless of the origin,TDs are an indicator of poor prognosis.Moreover,for BC,sentinel lymph node biopsy is generally used at present.Whether radical axillary lymph node dissection should be adopted for BC with TDs in axillary lymph nodes is still inconclusive.The present commentary of this clinical issue has certain guiding significance.It is aimed to increase the awareness of the scientific community towards this under-recognized problem in BC pathology.展开更多
Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this...Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this paper studies the depositional process of the hyperpycnal flow deposits,and divides their depositional process into three phases,namely,acceleration,erosion and deceleration.In the acceleration phase,hyperpycnal flow begins to enter the basin nearby,and then speeds up gradually.Deposits developed in the acceleration phase are reverse.In addition,the original deposits become unstable and are taken away by hyperpycnal flows under the eroding force.As a result,there are a lot of mixture of red mud pebbles outside the basin and gray mud pebbles within the basin.In the erosion phase,the reverse deposits are eroded and become thinner or even disappear.Therefore,no reverse grading characteristic is found in the proximal major channel that is closer to the source,but it is still preserved in the middle branch channel that is far from the source.After entering the deceleration phase,normally grading deposits appear and cover previous deposits.The final deposits in the basin are special.Some are reverse,and others are normal.They are superimposed with each other under the action of hyperpycnal flow.The analysis of the Sangyuan outcrop demonstrates the sedimentary process and distribution of hyperpycnites,and reasonably explain the sedimentary characteristics of hyperpycnites.It is helpful to the prediction of oil and gas exploration targets in gravity flow deposits.展开更多
The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by...The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by detailed field investigations,regional geological data,and extensive sample collections,including mineralized ore,altered wall rock,and unaltered basalt samples,for orebearing and geochemical analyses.Comparative analysis between altered and unaltered basalt samples revealed a mineral assemblage of sericite,quartz,and pyrite.This mineral composition forms through the hydrothermal alteration of unaltered basalt,originally containing feldspar,pyroxene,and ilmenite.The wall rock primarily features sericite,quartz,and hematite.During the alteration process,major,trace,and rare earth elements notably migrate.In the Jiadi deposit,K_(2)O,Rb,Au,and REE significantly increase,while Na_(2)O,CaO,MgO,and MnO decrease.SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)levels remain relatively stable.In the Damaidi deposit,K_(2)O,Rb,and Au enrich,contrasting with the depletion of Na_(2)O,CaO,MgO,and MnO,while SiO_(2),Fe_(2)O_(3),Al_(2)O_(3),TiO_(2),and REE show no significant changes.In the wall rock,TiO_(2),Al_(2)O_(3),K_(2)O,and REE increase,while Na_(2)O,CaO,MgO,and MnO decrease;SiO_(2)and Fe_(2)O_(3)content remains unchanged.The mineralization process likely originated from mid-to low-temperature,reductive magmatic hydrothermal fluids rich in CO_(2),CH_(4),N_(2),H^(+),S^(2-),HS^(-),H_(3)AsO_(3),and[Au(HS_(2)]^(-).These fluids migrated to tectonically weak zones in the Lianhuashan area,where Emeishan basalts are present.They reacted with Fe-bearing minerals in the basalt,such as ferro-hornblende and ilmenite,forming pyrite,arsenic-bearing pyrite,and arsenopyrite,thus enriching Au in these minerals.Additionally,K^(+)and H^(+)in the fluid reacted with plagioclase in the basalt,forming sericite and quartz.As the fluid entered the wall rock from structural weak zones,its oxidation increased,leading to the complete or partial reaction of Fe-bearing minerals in the wall rock,resulting in the formation of hematite or magnetite.This mineralization process is similar to that observed in carbonate-hosted Carlin-type gold deposits in southwest Guizhou,with the primary distinction being the iron source.In carbonate deposits,iron originates from ferridolomite within the wall rock,while in basalt-hosted deposits,it derives from ferripyroxene and ilmenite.展开更多
Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion vo...Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion volumes.However,the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited extent.To address this issue,this study investigates the impacts of three soil crust conditions(i.e.,without crust,10-minute crust,and 20-minute crust)on gully morphology,rainfall infiltration,and runoff and sediment yield during slope erosion of colluvial deposits with granite residues(classified as Acrisols)in Yudu County,Ganzhou City,Jiangxi Province,China,using simulated rainfall tests and photographic methods.The results showed that as the strength of the soil crust increased,the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased;at the same time,the runoff ratio increased.The sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests,respectively.These results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration,while providing valuable insights for the management of soil erosion in natural environments.展开更多
Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood...Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood. This study, through a comprehensive review of MVT deposits across global fold-and-thrust belts, introduces a novel model elucidating the mineralization process in the context of tectonic belt evolution. It is demonstrated that during the stage Ⅰ, regional compression is introduced by early stages of plate convergence, causing the folding and thrusting and creating structural or lithological traps such as evaporite diapirs and unconformity-related carbonate dissolution-collapse structures. Thereafter, in stage Ⅱ, hydrocarbons begin to migrate and accumulate within these traps, where reduced sulfur is generated through thermochemical or bacterial sulfate reduction concurrent with or preceding Zn-Pb mineralization. In the subsequent stage Ⅲ, as plate convergence persists, the regional stress transitions from compression to transpression or extension. Under these conditions, steeply-dipping extensional faults are generated, facilitating the ascent of metalliferous brines into early-formed structural or lithological traps. Precipitation of Zn and Pb sulfides occurs through the mixing of Zn-Pb-transporting fluids with pre-existing reduced sulfur or by interaction with hydrocarbons.展开更多
Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,20...Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,2018).It is an important part of the Central Orogenic Belt(Xiong et al.,2023).It is considered one of the important gold mineralization regions in the Tethys tectonic domain(Norbu et al.,2023)and an essential potential base for mineral resources in China.Wulonggou and Gouli gold mines have been discovered successively,earning the reputation of the"Golden Belt of Qinghai Province"(Feng et al.,2004;He et al.,2023).展开更多
In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume exper...In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume experiment demonstrated that storm-induced liquefaction deposits are formed by the oscillations of liquefied sediments.In this paper,the particle size distribution and ^(210)Pb_(ex) specific activity of the sediment samples from the liquefaction disturbed zone and adjacent stable zone of the Yellow River Delta were tested.The stratigraphic divisions based on storm liquefaction deposit sequence can effectively explain the vertical changes in particle size and ^(210)Pb_(ex) specific activity.Due to the differentiation of particles during the storm induced liquefaction,coarse and fine particles regrouped,which could explain the phenomenon of time-reversal in dating data.展开更多
Up to now, the evaporation and condensation, as well as the biological absorption and inorganic absorptions, have been proved to be major factors in Cd isotope fractionation. And Cd isotopes have been widely applied i...Up to now, the evaporation and condensation, as well as the biological absorption and inorganic absorptions, have been proved to be major factors in Cd isotope fractionation. And Cd isotopes have been widely applied in studies on the universal evolution and marine environment and so on. However, only a few researches have been conducted in applying Cd isotopes to trace the source of metallogenic material and the evolution of the ore-forming fluid in a complex mineralization environment, especially in a hydrothermal ore-formation system. We measured the Cd isotopic compositions of sphalerite, galena, and ores from five lead-zinc deposits in SW China, and found that the ~14/11~Cd values varied from -1.53%o to 0.34%0, with a total range of 1.87%o, which is greater than most of measured geological samples. Meanwhile, through contrasting the Cd content with Cd isotopic compositions of different deposits, it may be concluded that different genetic lead-zinc deposits have different Cd content and isotopic compositions, which could be a tool for the studies on the origin of ore deposits. Also, the biominera]iza- tion and crystal fractionation may also result in Cd isotope fractionation. In a word, although the research of Cd isotopes is presently at the preliminary stage （especially in hydrothermal ore-formation system）, this study demonstrated that Cd isotopes can give a clue in tracing the evolution of ore-forming fluid and metallogenic environment.展开更多
A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous n...A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous novel lithium resources. Given the presence of varied classification criteria for lithium resources presently, this study further ascertained and classified the lithium resources according to their occurrence modes, obtaining 10 types and 5 subtypes of lithium deposits(resources) based on endogenetic and exogenetic factors. As indicated by surveys of Cenozoic exogenetic lithium deposits in China and abroad,the formation and distribution of the deposits are primarily determined by plate collision zones, their primary material sources are linked to the anatectic magmas in the deep oceanic crust, and they were formed primarily during the Miocene and Late Paleogene. The researchers ascertained that these deposits,especially those of the salt lake, geothermal, and volcanic deposit types, are formed by unique slightly acidic magmas, tend to migrate and accumulate toward low-lying areas, and display supernormal enrichment. However, the material sources of lithium deposits(resources) of the Neopaleozoic clay subtype and the deep brine type are yet to be further identified. Given the various types and complex origins of lithium deposits(resources), which were formed due to the interactions of multiple spheres, it is recommended that the mineralization of exogenetic lithium deposits(resources) be investigated by integrating tectono-geochemistry, paleoatmospheric circulation, and salinology. So far, industrialized lithium extraction is primarily achieved in lithium deposits of the salt lake, clay, and hard rock types. The lithium extraction employs different processes, with lithium extraction from salt lake-type lithium deposits proving the most energy-saving and cost-effective.展开更多
BACKGROUND Based on the clinical data of colorectal cancer(CRC)patients who underwent surgery at our institution,a model for predicting the formation of tumor deposits(TDs)in this patient population was established.AI...BACKGROUND Based on the clinical data of colorectal cancer(CRC)patients who underwent surgery at our institution,a model for predicting the formation of tumor deposits(TDs)in this patient population was established.AIM To establish an effective model for predicting TD formation,thus enabling clinicians to identify CRC patients at high risk for TDs and implement personalized treatment strategies.METHODS CRC patients(n=645)who met the inclusion criteria were randomly divided into training(n=452)and validation(n=193)cohorts using a 7:3 ratio in this retrospective analysis.Least absolute shrinkage and selection operator regression was employed to screen potential risk factors,and multivariable logistic regression analysis was used to identify independent risk factors.Subsequently,a predictive model for TD formation in CRC patients was constructed based on the independent risk factors.The discrimination ability of the model,its consistency with actual results,and its clinical applicability were evaluated using receiveroperating characteristic curves,area under the curve(AUC),calibration curves,and decision curve analysis(DCA).RESULTS Thirty-four(7.5%)patients with TDs were identified in the training cohort based on postoperative pathological specimens.Multivariate logistic regression analysis identified female sex,preoperative intestinal obstruction,left-sided CRC,and lymph node metastasis as independent risk factors for TD formation.The AUCs of the nomogram models constructed using these variables were 0.839 and 0.853 in the training and validation cohorts,respectively.The calibration curve demonstrated good consistency,and the training cohort DCA yielded a threshold probability of 7%-78%.CONCLUSION This study developed and validated a nomogram with good predictive performance for identifying TDs in CRC patients.Our predictive model can assist surgeons in making optimal treatment decisions.展开更多
BACKGROUND Colorectal cancer is a frequent cause of cancer-related mortality in patients with lymph node or distant metastases.Pericolonic tumor deposits(TDs)are considered prognostically distinct from lymph node meta...BACKGROUND Colorectal cancer is a frequent cause of cancer-related mortality in patients with lymph node or distant metastases.Pericolonic tumor deposits(TDs)are considered prognostically distinct from lymph node metastases.AIM To investigate risk factors for extranodal TDs in stage III colon cancer.METHODS This was a retrospective cohort study.We selected 155 individuals diagnosed with stage III colon cancer from the database of the Cancer Registry of the Tri-Service General Hospital.The patients were allocated into the groups with/without N1c.Multivariate Cox regression analysis and Kaplan-Meier method were done.The primary outcomes investigate the association between the covariates and extranodal TDs,and prognostic significance of the covariates regarding the survival.RESULTS There were 136 individuals in the non-N1c group and 19 individuals in the N1c group.Patients with lymphovascular invasion(LVI)had a higher risk of TDs.Overall survival rates of patients with and without LVI were 6.64 years and 8.61 years,respectively(P=0.027).The N1c patients without LVI had higher overall survival than those who with LVI(7.73 years vs 4.42 years,P=0.010).CONCLUSION Patients having stage III colon cancer with LVI have a higher probability of having TDs than those with stage III colon cancer without LVI.Stage III colon cancer patients with TDs and LVI could have poor prognosis and outcome.展开更多
Deep-water gravity depositional processes and evolution in arc systems have become topics of intense research focus in recent years.This study discusses the co-evolution of volcanism and deep-water gravity flow deposi...Deep-water gravity depositional processes and evolution in arc systems have become topics of intense research focus in recent years.This study discusses the co-evolution of volcanism and deep-water gravity flow deposits at the southern margin of the Junggar Basin,based on petrology,geochronology and geochemical analyses.The results show that a massive collapse of unstable sediments from the slope was triggered by volcanism,resulting in the formation of slumping gravity flows.The occurrence of volcanic beds in the slump deposits confirm that synchronous volcanism likely affected sediment instability,triggering gravity flows.The Th/Yb,Ta/Yb and Th/Ta elemental ratios,U-Pb ages of detrital zircons and paleocurrent directions indicate that the North Tianshan(NTS)island arc represents the provenance of the Qianxia Formation.Moreover,statistical data on the pyroclastic components in the gravity flow deposits reveal an intensity index of volcanism,indicating that volcanism is strongly related to gravity flow deposits,especially in terms of the type and distribution of the deposits.A model for volcanically-triggered deep-water gravity flow deposits is established,in order to provide a more in-depth understanding of the co-evolution of volcanism and gravity flow deposits within the depositional setting of the late Paleozoic NTS oceanic subduction margin in the Junggar Basin.展开更多
BACKGROUND The current prognostic significance of perigastric tumor deposits(TDs)in gastric cancer(GC)remains unclear.AIM To assess the prognostic value of perigastric TDs and put forward a new TNM staging framework i...BACKGROUND The current prognostic significance of perigastric tumor deposits(TDs)in gastric cancer(GC)remains unclear.AIM To assess the prognostic value of perigastric TDs and put forward a new TNM staging framework involving TDs for primary GC.METHODS This study retrospectively analyzed the pathological data of 6672 patients with GC who underwent gastrectomy or surgery for GC with other diseases from January 1,2012 to December 31,2017 at the Chinese PLA General Hospital.According to the presence of perigastric TDs or not,the patients were divided into TD-positive and TD-negative groups by using the method of propensity score matching.The differences between TD-positive and TD-negative patients were analyzed using binary logistic regression modeling.The Kaplan-Meier method was used to plot survival curves.Multivariate Cox regression modeling and the log-rank test were used to analyze the data.RESULTS Perigastric TDs were found to be positive in 339(5.09%)of the 6672 patients with GC,among whom 237 were men(69.91%)and 102 were women(30.09%)(2.32:1).The median age was 59 years(range,27 to 78 years).Univariate and multivariate survival analyses indicated that TD-positive GC patients had a poorer prognosis than TD-negative patients(P<0.05).The 1-,3-,and 5-year overall survival rates of GC patients with TDs were 68.3%,19.6%,and 11.2%,respectively,and these were significantly poorer than those without TDs of the same stages.There was significant variation in survival according to TD locations among the GC patients(P<0.05).A new TNM staging framework for GC was formulated according to TD location.When TDs appear in the gastric body,the original stages T1,T2,and T3 are classified as T4a with the new framework,and the original stages T4a and T4b both are classified as T4b.When TDs appear in the lesser curvature,the previous stages N0,N1,N2,and N3 now both are classified as N3.When TDs appear in the greater curvature or the distant tissue,the patient should be categorized as having M1.With the new GC staging scheme including TDs,the survival curves of patients in the lower grade TNM stage with TDs were closer to those of patients in the higher grade TNM stage without TDs.CONCLUSION TDs are a poor prognostic factor for patients with primary GC.The location of TDs is associated with the prognosis of patients with primary GC.Accordingly,we developed a new TNM staging framework involving TDs that is more appropriate for patients with primary GC.展开更多
Through core observation,thin section identification,and logging and testing data analysis,the types and characteristics of event deposits in the ninth member of Yanchang Formation of Triassic(Chang 9 Member)in southw...Through core observation,thin section identification,and logging and testing data analysis,the types and characteristics of event deposits in the ninth member of Yanchang Formation of Triassic(Chang 9 Member)in southwestern Ordos Basin,China,are examined.There are 4 types and 9 subtypes of event deposits,i.e.earthquake,gravity flow,volcanic and anoxic deposits,in the Chang 9 Member in the study area.Based on the analysis of the characteristics and distribution of such events deposits,it is proposed that the event deposits are generally symbiotic or associated,with intrinsic genetic relations and distribution laws.Five kinds of sedimentary microfacies with relatively developed event deposits are identified,and the genetic model of event deposits is discussed.Seismites are mainly developed in the lake transgression stage when the basin expands episodically,and commonly affected by liquefaction flow,gravity action and brittle shear deformation.Gravity flow,mainly distributed in the high water level period,sandwiched in the fine-grained sediments of prodelta or semi-deep lake,or creates banded or lobate slump turbidite fan.It is relatively developed above the seismites strata.The volcanic event deposits are only seen in the lower part of the Chang 9 Member,showing abrupt contact at the top and bottom,which reflects the volcanic activity at the same time.Anoxic deposits are mostly formed in the late stage of lake transgression to the highstand stage.Very thick organic-rich shales are developed in the highstand stage of Chang 9 Member,and the event deposits in the depositional period of these shales are conducive to potential reservoirs.展开更多
基金granted by the China State Mineral Resources Investigation Program (Grant No.12120113050700)
文摘Mississippi-Valley＇s carbonate-type （MVT） lead-zinc deposits are the most important type of lead-zinc deposits in the southwest of China. In 2013, China Geological Survey Bureau deployed a project named ＂Experimental Investigation of Integrated Prospecting Technology for Concealed Carbonate-Type Lead-Zinc Deposits in the Region of Sichuan, Yunnan and Guizhou Provinces＂. This project has been implemented by the Chengdu Center of China Geological Survey since 2013, and the project has run for 3 years. The general objective of this project is to establish an effective and adaptable integrated prospecting methodology （including geological, geophysical and geochemical techniques） in search for deep concealed lead-zinc deposits.
基金Projects(41572060,41802089,U1133602)supported by the National Natural Science Foundation of ChinaProject(2017M610614)supported by the Postdoctoral Science Foundation,ChinaProjects(2008,2012)supported by the YM Lab [2011] and Innovation Team of Yunnan Province and KMUST,China
文摘Most of the lead and zinc deposits in Southwest China, are characterized by mineral zoning, which is especially true for the Huize and Zhaotong deposits. The mineral assemblage zoning is consistent for both horizontal and vertical zoning, from the base(center) of the ore body to the top(outermost), the mineral zones are as follows. I-1: coarse-grained pyrite and a little puce sphalerite;I-2: brown sphalerite, galena, and ferro-dolomite;I-3: galena, sandy beige and pale yellow sphalerite, and calcite;and I-4: fine-grained pyrite, dolomite, and calcite. Among them, sphalerite is the landmark mineral of different zoning. From I-1 to I-3, the color of sphalerite changes from dark to light, its crystalline size changes from coarse to fine, and its structure changes from disseminated to veinlet. This mineral zoning is seen not only on a microscopic scale, but is also clear on a mesoscopic and macroscopic scale. It is caused by the order of the sphalerite and galena precipitation. We studied the metallic minerals and fluid inclusions using a thermodynamic phase diagram method, such as lgfO2–lgfS2, pH–lgfO2, pH–lg[Pb^2+] and pH–lg[HS^-], discussed the constraints on the order of the sphalerite and galena precipitation in the migration and precipitation process of lead and zinc under different pH values, oxygen fugacity, sulfur fugacity, and ionic activity. We also explain the formation mechanism and propose that the main controlling factor of the order of the sphalerite and galena precipitation is sulfur fugacity.
文摘An attempt is made in this paper to describe the following laws governing the distribution of lead-zinc deposits in China: spatial distribution laws, temporal distribution laws, deep level control laws, and deposits association and zoning laws.
文摘Qinling-type Pb-Zn deposits are located in the Qinling fold belt, occurring in the fine-clastic and carbonate rocks of the Devonian marine facies. They are reformed sedimentary deposits originating from hydrothermal waters, and may be subdivided into 2 subtypes: hydrothermal sedimentary deposits (Changba subtype) and reformed hydrothermal sedimentary deposits (Bijiashan-Qiandongshan subtype). In comparison with some of the famous Palaeozoic Pb-Zn deposits in the world, the Qinling-type Pb-Zn deposits constitute an independent type, which possesses some characteristics of both hydrothermal sedimentary deposits (Meggen type) and reformed hydrothermal deposits (Mississippi Valley type).
文摘Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary tumor.By definition,no residual lymph node structure should be identified in these tumor masses.At present,TDs are mainly reported in colorectal cancer,with a few reports in gastric cancer.There are very few reports on breast cancer(BC).For TDs,current dominant theories suggest that these are the result of lymph node metastasis of the tumor with complete destruction of the lymph nodes by the tumor tissue.Even some pathologists classify a TD as two lymph node metastases for calculation.Some pathologists also believe that TDs belong to the category of disseminated metastasis.Therefore,regardless of the origin,TDs are an indicator of poor prognosis.Moreover,for BC,sentinel lymph node biopsy is generally used at present.Whether radical axillary lymph node dissection should be adopted for BC with TDs in axillary lymph nodes is still inconclusive.The present commentary of this clinical issue has certain guiding significance.It is aimed to increase the awareness of the scientific community towards this under-recognized problem in BC pathology.
基金the Scientific research and technology development project of Petro China(2021DJ5303)。
文摘Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this paper studies the depositional process of the hyperpycnal flow deposits,and divides their depositional process into three phases,namely,acceleration,erosion and deceleration.In the acceleration phase,hyperpycnal flow begins to enter the basin nearby,and then speeds up gradually.Deposits developed in the acceleration phase are reverse.In addition,the original deposits become unstable and are taken away by hyperpycnal flows under the eroding force.As a result,there are a lot of mixture of red mud pebbles outside the basin and gray mud pebbles within the basin.In the erosion phase,the reverse deposits are eroded and become thinner or even disappear.Therefore,no reverse grading characteristic is found in the proximal major channel that is closer to the source,but it is still preserved in the middle branch channel that is far from the source.After entering the deceleration phase,normally grading deposits appear and cover previous deposits.The final deposits in the basin are special.Some are reverse,and others are normal.They are superimposed with each other under the action of hyperpycnal flow.The analysis of the Sangyuan outcrop demonstrates the sedimentary process and distribution of hyperpycnites,and reasonably explain the sedimentary characteristics of hyperpycnites.It is helpful to the prediction of oil and gas exploration targets in gravity flow deposits.
基金funded by the Talent Team Program of Science and Technology Foundation of Guizhou Province(CXTD[2021]007)the Key Project of Natural Science Basic Research Program of Shannxi Province(2023-JC-ZD-16)+4 种基金the National Natural Science Fund of China(U1812402)the National Natural Science Fund of China(41962008)the National Key Research and Development Program of China“Exploration and Exploitation of Deep Earth Resources”(2017YFC0601500)the Guizhou Province Graduate Research Fund(YJSCXJH[2020]095)the public welfare and fundamental project Fund of Guizhou Province(520000214 TLCOG7DGTNRG)。
文摘The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by detailed field investigations,regional geological data,and extensive sample collections,including mineralized ore,altered wall rock,and unaltered basalt samples,for orebearing and geochemical analyses.Comparative analysis between altered and unaltered basalt samples revealed a mineral assemblage of sericite,quartz,and pyrite.This mineral composition forms through the hydrothermal alteration of unaltered basalt,originally containing feldspar,pyroxene,and ilmenite.The wall rock primarily features sericite,quartz,and hematite.During the alteration process,major,trace,and rare earth elements notably migrate.In the Jiadi deposit,K_(2)O,Rb,Au,and REE significantly increase,while Na_(2)O,CaO,MgO,and MnO decrease.SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)levels remain relatively stable.In the Damaidi deposit,K_(2)O,Rb,and Au enrich,contrasting with the depletion of Na_(2)O,CaO,MgO,and MnO,while SiO_(2),Fe_(2)O_(3),Al_(2)O_(3),TiO_(2),and REE show no significant changes.In the wall rock,TiO_(2),Al_(2)O_(3),K_(2)O,and REE increase,while Na_(2)O,CaO,MgO,and MnO decrease;SiO_(2)and Fe_(2)O_(3)content remains unchanged.The mineralization process likely originated from mid-to low-temperature,reductive magmatic hydrothermal fluids rich in CO_(2),CH_(4),N_(2),H^(+),S^(2-),HS^(-),H_(3)AsO_(3),and[Au(HS_(2)]^(-).These fluids migrated to tectonically weak zones in the Lianhuashan area,where Emeishan basalts are present.They reacted with Fe-bearing minerals in the basalt,such as ferro-hornblende and ilmenite,forming pyrite,arsenic-bearing pyrite,and arsenopyrite,thus enriching Au in these minerals.Additionally,K^(+)and H^(+)in the fluid reacted with plagioclase in the basalt,forming sericite and quartz.As the fluid entered the wall rock from structural weak zones,its oxidation increased,leading to the complete or partial reaction of Fe-bearing minerals in the wall rock,resulting in the formation of hematite or magnetite.This mineralization process is similar to that observed in carbonate-hosted Carlin-type gold deposits in southwest Guizhou,with the primary distinction being the iron source.In carbonate deposits,iron originates from ferridolomite within the wall rock,while in basalt-hosted deposits,it derives from ferripyroxene and ilmenite.
基金This work was supported by the National Natural Science Foundation of China[Grant Nos.41962015,52208348]the Jiangxi Provincial Natural Science Foundation[Grant No.20224BAB214064,20232BAB204083].
文摘Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion volumes.However,the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited extent.To address this issue,this study investigates the impacts of three soil crust conditions(i.e.,without crust,10-minute crust,and 20-minute crust)on gully morphology,rainfall infiltration,and runoff and sediment yield during slope erosion of colluvial deposits with granite residues(classified as Acrisols)in Yudu County,Ganzhou City,Jiangxi Province,China,using simulated rainfall tests and photographic methods.The results showed that as the strength of the soil crust increased,the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased;at the same time,the runoff ratio increased.The sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests,respectively.These results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration,while providing valuable insights for the management of soil erosion in natural environments.
基金funded by National Natural Science Foundation of China (Grant Nos. 42125204, 92155305, 42103068, 42372114, 42372115)。
文摘Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood. This study, through a comprehensive review of MVT deposits across global fold-and-thrust belts, introduces a novel model elucidating the mineralization process in the context of tectonic belt evolution. It is demonstrated that during the stage Ⅰ, regional compression is introduced by early stages of plate convergence, causing the folding and thrusting and creating structural or lithological traps such as evaporite diapirs and unconformity-related carbonate dissolution-collapse structures. Thereafter, in stage Ⅱ, hydrocarbons begin to migrate and accumulate within these traps, where reduced sulfur is generated through thermochemical or bacterial sulfate reduction concurrent with or preceding Zn-Pb mineralization. In the subsequent stage Ⅲ, as plate convergence persists, the regional stress transitions from compression to transpression or extension. Under these conditions, steeply-dipping extensional faults are generated, facilitating the ascent of metalliferous brines into early-formed structural or lithological traps. Precipitation of Zn and Pb sulfides occurs through the mixing of Zn-Pb-transporting fluids with pre-existing reduced sulfur or by interaction with hydrocarbons.
基金supported by Qinghai Provincial Association for Science and Technology Youth Science and Technology Talent Support Project(Grant No.2023QHSKXRCTJ47)Exploration Foundation of Qinghai Province(Grant No.2023085029ky004)。
文摘Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,2018).It is an important part of the Central Orogenic Belt(Xiong et al.,2023).It is considered one of the important gold mineralization regions in the Tethys tectonic domain(Norbu et al.,2023)and an essential potential base for mineral resources in China.Wulonggou and Gouli gold mines have been discovered successively,earning the reputation of the"Golden Belt of Qinghai Province"(Feng et al.,2004;He et al.,2023).
基金funding for this project was provided by the National Natural Science Foundation of China (No.41976049)。
文摘In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume experiment demonstrated that storm-induced liquefaction deposits are formed by the oscillations of liquefied sediments.In this paper,the particle size distribution and ^(210)Pb_(ex) specific activity of the sediment samples from the liquefaction disturbed zone and adjacent stable zone of the Yellow River Delta were tested.The stratigraphic divisions based on storm liquefaction deposit sequence can effectively explain the vertical changes in particle size and ^(210)Pb_(ex) specific activity.Due to the differentiation of particles during the storm induced liquefaction,coarse and fine particles regrouped,which could explain the phenomenon of time-reversal in dating data.
基金supported by National Basic Research Program of China(Grant No.2009CB421005)Chinese Academy of Sciences for Key Topics in Innovation Engineering(Grant No.KZCX2-YW-Q04-01)
文摘Up to now, the evaporation and condensation, as well as the biological absorption and inorganic absorptions, have been proved to be major factors in Cd isotope fractionation. And Cd isotopes have been widely applied in studies on the universal evolution and marine environment and so on. However, only a few researches have been conducted in applying Cd isotopes to trace the source of metallogenic material and the evolution of the ore-forming fluid in a complex mineralization environment, especially in a hydrothermal ore-formation system. We measured the Cd isotopic compositions of sphalerite, galena, and ores from five lead-zinc deposits in SW China, and found that the ~14/11~Cd values varied from -1.53%o to 0.34%0, with a total range of 1.87%o, which is greater than most of measured geological samples. Meanwhile, through contrasting the Cd content with Cd isotopic compositions of different deposits, it may be concluded that different genetic lead-zinc deposits have different Cd content and isotopic compositions, which could be a tool for the studies on the origin of ore deposits. Also, the biominera]iza- tion and crystal fractionation may also result in Cd isotope fractionation. In a word, although the research of Cd isotopes is presently at the preliminary stage （especially in hydrothermal ore-formation system）, this study demonstrated that Cd isotopes can give a clue in tracing the evolution of ore-forming fluid and metallogenic environment.
基金funded by the major research program of the of National Natural Science Foundation of China entitled Metallogenic Mechanisms and Regularity of the Lithium Ore Concentration Area in the Zabuye Salt Lake, Tibet (91962219)Science and Technology Major Project of the Tibet Autonomous Region ’s Science and Techonlogy Plan (XZ202201ZD0004G01)a geological survey project of China Geological Survey (DD20230037)。
文摘A reasonable classification of deposits holds great significance for identifying prospecting targets and deploying exploration. The world ’s keen demand for lithium resources has expedited the discovery of numerous novel lithium resources. Given the presence of varied classification criteria for lithium resources presently, this study further ascertained and classified the lithium resources according to their occurrence modes, obtaining 10 types and 5 subtypes of lithium deposits(resources) based on endogenetic and exogenetic factors. As indicated by surveys of Cenozoic exogenetic lithium deposits in China and abroad,the formation and distribution of the deposits are primarily determined by plate collision zones, their primary material sources are linked to the anatectic magmas in the deep oceanic crust, and they were formed primarily during the Miocene and Late Paleogene. The researchers ascertained that these deposits,especially those of the salt lake, geothermal, and volcanic deposit types, are formed by unique slightly acidic magmas, tend to migrate and accumulate toward low-lying areas, and display supernormal enrichment. However, the material sources of lithium deposits(resources) of the Neopaleozoic clay subtype and the deep brine type are yet to be further identified. Given the various types and complex origins of lithium deposits(resources), which were formed due to the interactions of multiple spheres, it is recommended that the mineralization of exogenetic lithium deposits(resources) be investigated by integrating tectono-geochemistry, paleoatmospheric circulation, and salinology. So far, industrialized lithium extraction is primarily achieved in lithium deposits of the salt lake, clay, and hard rock types. The lithium extraction employs different processes, with lithium extraction from salt lake-type lithium deposits proving the most energy-saving and cost-effective.
基金Fujian Province Science and Technology Innovation Joint Fund Project,No.2021Y9029.
文摘BACKGROUND Based on the clinical data of colorectal cancer(CRC)patients who underwent surgery at our institution,a model for predicting the formation of tumor deposits(TDs)in this patient population was established.AIM To establish an effective model for predicting TD formation,thus enabling clinicians to identify CRC patients at high risk for TDs and implement personalized treatment strategies.METHODS CRC patients(n=645)who met the inclusion criteria were randomly divided into training(n=452)and validation(n=193)cohorts using a 7:3 ratio in this retrospective analysis.Least absolute shrinkage and selection operator regression was employed to screen potential risk factors,and multivariable logistic regression analysis was used to identify independent risk factors.Subsequently,a predictive model for TD formation in CRC patients was constructed based on the independent risk factors.The discrimination ability of the model,its consistency with actual results,and its clinical applicability were evaluated using receiveroperating characteristic curves,area under the curve(AUC),calibration curves,and decision curve analysis(DCA).RESULTS Thirty-four(7.5%)patients with TDs were identified in the training cohort based on postoperative pathological specimens.Multivariate logistic regression analysis identified female sex,preoperative intestinal obstruction,left-sided CRC,and lymph node metastasis as independent risk factors for TD formation.The AUCs of the nomogram models constructed using these variables were 0.839 and 0.853 in the training and validation cohorts,respectively.The calibration curve demonstrated good consistency,and the training cohort DCA yielded a threshold probability of 7%-78%.CONCLUSION This study developed and validated a nomogram with good predictive performance for identifying TDs in CRC patients.Our predictive model can assist surgeons in making optimal treatment decisions.
文摘BACKGROUND Colorectal cancer is a frequent cause of cancer-related mortality in patients with lymph node or distant metastases.Pericolonic tumor deposits(TDs)are considered prognostically distinct from lymph node metastases.AIM To investigate risk factors for extranodal TDs in stage III colon cancer.METHODS This was a retrospective cohort study.We selected 155 individuals diagnosed with stage III colon cancer from the database of the Cancer Registry of the Tri-Service General Hospital.The patients were allocated into the groups with/without N1c.Multivariate Cox regression analysis and Kaplan-Meier method were done.The primary outcomes investigate the association between the covariates and extranodal TDs,and prognostic significance of the covariates regarding the survival.RESULTS There were 136 individuals in the non-N1c group and 19 individuals in the N1c group.Patients with lymphovascular invasion(LVI)had a higher risk of TDs.Overall survival rates of patients with and without LVI were 6.64 years and 8.61 years,respectively(P=0.027).The N1c patients without LVI had higher overall survival than those who with LVI(7.73 years vs 4.42 years,P=0.010).CONCLUSION Patients having stage III colon cancer with LVI have a higher probability of having TDs than those with stage III colon cancer without LVI.Stage III colon cancer patients with TDs and LVI could have poor prognosis and outcome.
基金jointly funded by the National Natural Science Foundation of China(Grant Nos.41972120,42172129)the State Key Laboratory of Paleobiology and Stratigraphy(Nanjing Institute of Geology and Paleontology,CAS)(Grant No.173131)+1 种基金the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(Grant No.2020CX050103)the China Postdoctoral Science Foundation(Grant No.2021M702720)。
文摘Deep-water gravity depositional processes and evolution in arc systems have become topics of intense research focus in recent years.This study discusses the co-evolution of volcanism and deep-water gravity flow deposits at the southern margin of the Junggar Basin,based on petrology,geochronology and geochemical analyses.The results show that a massive collapse of unstable sediments from the slope was triggered by volcanism,resulting in the formation of slumping gravity flows.The occurrence of volcanic beds in the slump deposits confirm that synchronous volcanism likely affected sediment instability,triggering gravity flows.The Th/Yb,Ta/Yb and Th/Ta elemental ratios,U-Pb ages of detrital zircons and paleocurrent directions indicate that the North Tianshan(NTS)island arc represents the provenance of the Qianxia Formation.Moreover,statistical data on the pyroclastic components in the gravity flow deposits reveal an intensity index of volcanism,indicating that volcanism is strongly related to gravity flow deposits,especially in terms of the type and distribution of the deposits.A model for volcanically-triggered deep-water gravity flow deposits is established,in order to provide a more in-depth understanding of the co-evolution of volcanism and gravity flow deposits within the depositional setting of the late Paleozoic NTS oceanic subduction margin in the Junggar Basin.
文摘BACKGROUND The current prognostic significance of perigastric tumor deposits(TDs)in gastric cancer(GC)remains unclear.AIM To assess the prognostic value of perigastric TDs and put forward a new TNM staging framework involving TDs for primary GC.METHODS This study retrospectively analyzed the pathological data of 6672 patients with GC who underwent gastrectomy or surgery for GC with other diseases from January 1,2012 to December 31,2017 at the Chinese PLA General Hospital.According to the presence of perigastric TDs or not,the patients were divided into TD-positive and TD-negative groups by using the method of propensity score matching.The differences between TD-positive and TD-negative patients were analyzed using binary logistic regression modeling.The Kaplan-Meier method was used to plot survival curves.Multivariate Cox regression modeling and the log-rank test were used to analyze the data.RESULTS Perigastric TDs were found to be positive in 339(5.09%)of the 6672 patients with GC,among whom 237 were men(69.91%)and 102 were women(30.09%)(2.32:1).The median age was 59 years(range,27 to 78 years).Univariate and multivariate survival analyses indicated that TD-positive GC patients had a poorer prognosis than TD-negative patients(P<0.05).The 1-,3-,and 5-year overall survival rates of GC patients with TDs were 68.3%,19.6%,and 11.2%,respectively,and these were significantly poorer than those without TDs of the same stages.There was significant variation in survival according to TD locations among the GC patients(P<0.05).A new TNM staging framework for GC was formulated according to TD location.When TDs appear in the gastric body,the original stages T1,T2,and T3 are classified as T4a with the new framework,and the original stages T4a and T4b both are classified as T4b.When TDs appear in the lesser curvature,the previous stages N0,N1,N2,and N3 now both are classified as N3.When TDs appear in the greater curvature or the distant tissue,the patient should be categorized as having M1.With the new GC staging scheme including TDs,the survival curves of patients in the lower grade TNM stage with TDs were closer to those of patients in the higher grade TNM stage without TDs.CONCLUSION TDs are a poor prognostic factor for patients with primary GC.The location of TDs is associated with the prognosis of patients with primary GC.Accordingly,we developed a new TNM staging framework involving TDs that is more appropriate for patients with primary GC.
基金Supported by the PetroChina Scientific Research and Technological Development Project(2021DJ0402).
文摘Through core observation,thin section identification,and logging and testing data analysis,the types and characteristics of event deposits in the ninth member of Yanchang Formation of Triassic(Chang 9 Member)in southwestern Ordos Basin,China,are examined.There are 4 types and 9 subtypes of event deposits,i.e.earthquake,gravity flow,volcanic and anoxic deposits,in the Chang 9 Member in the study area.Based on the analysis of the characteristics and distribution of such events deposits,it is proposed that the event deposits are generally symbiotic or associated,with intrinsic genetic relations and distribution laws.Five kinds of sedimentary microfacies with relatively developed event deposits are identified,and the genetic model of event deposits is discussed.Seismites are mainly developed in the lake transgression stage when the basin expands episodically,and commonly affected by liquefaction flow,gravity action and brittle shear deformation.Gravity flow,mainly distributed in the high water level period,sandwiched in the fine-grained sediments of prodelta or semi-deep lake,or creates banded or lobate slump turbidite fan.It is relatively developed above the seismites strata.The volcanic event deposits are only seen in the lower part of the Chang 9 Member,showing abrupt contact at the top and bottom,which reflects the volcanic activity at the same time.Anoxic deposits are mostly formed in the late stage of lake transgression to the highstand stage.Very thick organic-rich shales are developed in the highstand stage of Chang 9 Member,and the event deposits in the depositional period of these shales are conducive to potential reservoirs.
