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Metallogeny of the Lannigou Sedimentary Rock-hosted Disseminated Gold Deposit in Southwestern Guizhou Province,China

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Acta Geologica Sinica(English Edition) 2007年第1期81卷 121-134页

作者： BAO Zhiwei jayanta guha Key Laboratory for MetaUogenic Dynamics Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou Guangdong 510640 China Earth Sciences/CERM University of Quebec at Chicoutimi Chicoutimi P.Q. G7H 2B1 Canada

The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold （SRHDG） deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicification, pyritization, arsenopyritization, carbonatization and argillization, commonly occur along fractures. PGE study demonstrates that either Permian basalts or Triassic ultrabasic intrnsives are unlikely to be the main source of gold mineralization. Coupled with the lack of other nmgmatic activity in the vicinity of the mining area, an amagmatic origin is proposed. Organic matter compositions and GC-MS analysis of the ores and host rocks show that the organics in the ores and the host rocks have a common source; the organic matter in the ores was mainly indigenous. The positive correlation between S2 and Au contents, along with the common occurrence of organic inclusions, suggest involvement of organic matter in the ore-forming process in terms of promoting Au leaching from the source rocks, making colloidal Au migration possible, as well as hydrocarbon reduction of sulphate. Geological and geochemical characteristics of the Lannigou deposit suggest that it was formed through circulation of meteoric water and probably less importantly organic bearing formation water driven by high geothermal gradient caused by late Yanshanian extension, which leached Au from the source bed, and then migrated as Au-bisnlfides and colloidal Au, culminating in deposition by reduction-adsorption and surface complexation of gold onto the growth surface of arsenlan pyrite.

关键词： sedimentary rock-hosted disseminated gold deposit metallogeny Lannigou Guizhou

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Microstructural analysis of a subhorizontal gold-quartz vein deposit at Donalda,Abitibi greenstone belt,Canada:Implications for hydrodynamic regime and fluid-structural relationship

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Geoscience Frontiers 2011年第4期2卷 529-538页

作者： Guoxiang Chi jayanta guha Department of Geology University of Regina Regina Saskatchewan Canada Sciences de la Terre/Centre d＇Etude sur les Ressources Minerales Universite du Quebec a Chicoutimi Chicoutimi Quebec Canada

The Donalda gold deposit in the southern part of the Archean Abitibi greenstone belt consists mainly of a subhonzontal gold-quartz vein perpendicular to subvertical shear *** 0.3—0.5 m thick vein is characterized by vein-parallel banding structures indicating multiple episodes of fracture opening and mineral *** of the c-axis of primary growth quartz indicates that quartz preferentially grew perpendicular to the fracture,suggesting open space filling and/or extensional nature of the *** of the orientations of microfractures,veinlets and fluid—inclusion planes（FIPs） crosscutting primary growth quartz indicates that the vein minerals were subject to a vertical maximum principal stress（σ_1）,which is inconsistent with the subhorizontalσ_1 inferred from the regional stress field with N—S *** apparent discrepancy is explained by invoking episodic fluid pressure fluctuation between supralithostatic and hydrostatic regimes accompanied by episodic opening and closing of the sub-horizontal *** fluid pressure was higher than the lithostatic value,the fracture was opened and primary growth minerals were precipitated,whereas when fluid pressure decreased toward the hydrostatic value,the hanging wall of the fracture collapsed,causing collision of protruding primary growth minerals from both sides of the fracture and resulting in formation of vein-parallel deformation *** columns where the two facing sides of the fracture collided were subject to higher-than-lithostatic stress due to the bridging effect and reduced support surface area,explaining the development of verticalσ_*** hypothesis is consistent the fault-valve model,and explains the flipping ofσ_1 without having to change the regional stress field.

关键词： Hydrodynamics Fluid-structural relationship Gold deposit Fluid inclusion planes Microstructural Subhorizontal veins

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Tendency and Fractal Pattern of Migration of Trace Elements in Source Rocks During Thermal Event

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Science China Chemistry 1994年第6期37卷 744-757页

作者：周永章 Edward H. Chown jayanta guha 卢焕章 Institute of Geochemistry Guangzhou Branch Academia Sinica Guangzhou 510640 PRC Sciences Appliqées Uniersityé du Qubec a ChicoutimiCanada G7H2B1

The reactivation of trace elements in source rocks is fundamental in the formation of many economic deposits. Although transport by fluid flow and infiltration is very effective along visible fractures, the migration of trace elements from the inner part of solid cells to the weaknesses is much less efficient, and so becomes the bottleneck in the migration of these elements from their initial positions in the source rock to the final deposition site in an ore body. Diffusion may play a key role in the reactivation of trace elements. The overall migration pattern of trace elements in source rocks is characterized by an embedded sink mosaic structure, which possesses the self-similarity of a fractal. There are two general migration tendencies of trace elements. One is from within solid cells, such as mineral grains, toward the sink, consisting of weaknesses in the source rock. The other is from high-temperature fields toward low-temperature ones. High temperature favors the realization of these two

关键词： migration trace element fractal embedded sink mosaic structure.

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Hydrogeochemistry of toxic metals in Au-As-Hg-Tl mineralized area in southwest Guizhou Province, China

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Chinese Science Bulletin 1999年第S2期44卷 171-172页

作者： Boyle Dan guha jayanta Mineral Resources Division Geological Survey of Canada Ottawa K1A OE8 Canada Science de la Terre Departement des Sciences Aplliquees Universite du Quebec a Chicoutimi Quebec G7H2B1 Canada

THE environmental geochemistry problems during the processes of mining activities are intensively considered by scientists worldwide, and the hydrogeochemistry presents an important implication of toxic metalcontamination related to mining activities. The hydrogeochemistry due to mining activities and naturalmineralized processes present some differences whose comparison can indicate a good understanding of theinfluence of mining on the environment. This ongoing study aims at the hydrogeochemistry of toxic metals in the Au-As-Hg-Tl metallogenicbelt of Huijiabao anticline in southwest Guizhou, China. The presently-mined Lanmuchang mercury-thallium deposit with a Hg-mining history of about 350 years containing one of the world’s highest concentration of thallium and the to-be-mined Yanshang gold deposit enriching high concentration of toxic metals have been chosen to study the hydrogeochemistry of toxic metals. The groundwater samples werecollected from the shallow aquifer in terms of spring, domestic well and karstic cave whereas the surfacewater was only sampled downside the surface drainage leaching the mine waste at Lanmuchang. All

关键词： toxic metals hydrogeochemistry Au-As-Hg-TI mineralized area southwest Guizhou Province.

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Hg and As Minerals in Fluid Inclusions from the Williams Mine, Hemlo, and Their Genetic Implications

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Chinese Journal Of Geochemistry 2002年第1期21卷 1-18页

作者：卢焕章 jayanta.guha DON.C.HARRIS Sciences de la Terre Universite du Quebec a Chicoutimi Chicoutimi Quebec Canada G7H 2B 1 Geological Survey of Canada 601 Booth Street Ottawa Ont. Canada K1A 0E8

The Hemlo mineralization is enigmatic compared to general Archean lode gold deposits based on the fact that it is characterized by an exotic mineralogy containing elements such as As, Hg, Sb, Ba, V and Mo. The genetic concepts range from syngenetic to epigenetic types of mineralization. This reconnaissance study was designed to examine the relationship of Hg-As minerals with respect to fluid inclusions in the Williams mine (formerly known as the Page Williams mine) covering the A and C ore zones.

关键词：流体包裹体含汞矿物含砷矿物矿化作用金矿床

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Mathematical Invariant and Quantitative Estimation on Element Migration of Hydrothermal Wall-Rock Alteration--With an Example of Application in the Hetai Gold Field, Guangdong Province, China

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Chinese Science Bulletin 1994年第19期39卷 1638-1643页

作者：周永章涂光炽 Edward H. Chown jayanta guha 卢焕章 Institute of Geochemistry Guangzhou Branch Academia Sinica Guangzhou 510640 PRC Universite du Quebec a Chicoutimi Canada G7H 2B1

Hydrothermal wall-rock alteration is the interaction of hydrothermal fluids with the wall rock, causing changes or redistribution of chemical compositions of initial wall *** study of hydrothermal alteration may enric... 详细信息

关键词： constant sum constraint conserved element balance estimation of mass element migration.

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加拿大Abitibi绿岩带Donalda金矿近水平含金石英脉的显微构造分析及其对成矿流体动力学的指示

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地学前缘 2011年第5期18卷 43-54页

作者：池国祥 jayanta guha 加拿大里贾纳大学地质系萨斯喀彻里贾纳S4S 0A2 加拿大魁北克大学希库蒂米分校魁北克希库蒂米

位于加拿大Abitibi绿岩带南部的Donalda金矿床主要由近水平的、与剪切带近垂直的含金石英脉组成,矿脉厚度0.3～0.5m,含大量与脉壁平行的条带,指示多期次裂隙扩张和矿物沉淀。原生石英c-轴方位测量显示石英生长方向垂直于脉壁,指示断裂... 详细信息

位于加拿大Abitibi绿岩带南部的Donalda金矿床主要由近水平的、与剪切带近垂直的含金石英脉组成,矿脉厚度0.3～0.5m,含大量与脉壁平行的条带,指示多期次裂隙扩张和矿物沉淀。原生石英c-轴方位测量显示石英生长方向垂直于脉壁,指示断裂属张性,矿物沉淀属空间充填。显微裂隙、细脉及流体包裹体面(FIPs)的方位测量指示原生矿物受到了近直立的最大主压应力(σ1)作用,与区域性的、近水平的南北向挤压应力不符。这一矛盾现象可用流体压力在超静岩和静水压力之间周期性变化及近水平断裂的周期性张开与闭合来解释。当流体压力大于静岩压力时,断裂张开,原生矿物沉淀,而当流体压力减小时,断裂上盘往下垮,两盘突出的矿物碰撞、碾压形成与脉壁平行的变形条带。由于断裂两盘岩石不是沿整条断裂都互相接触,两盘相顶部分承受的垂直应力大于水平方向的挤压应力,这就解释了为什么显微构造指示近直立的最大主压应力(σ1)。这个流体-构造模式支持断层阀模式,并且无须改变区域应力场就可解释脉体内局部主压应力的变化。

关键词：流体动力学流体-构造关系造山型金矿流体包裹体面显微构造

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象牙海岸Issia地区铌钽砂矿的研究(英文)

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大地构造与成矿学 2008年第2期32卷 195-211页

作者： Benjamin A ALLOU Huanzhang LU jayanta guha Jacques CARIGNAN Centre d＇études sur les Ressources Minérales Université du Quebec à Chicoutimi 555 Bd de l＇ Université Chicoutimi Québec Canada G7H2B1 Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 Guangdong China

在西非的象牙海岸Issia地区分布着许多铌钽矿床,包括原生矿和砂矿。原生矿产在分带很好的伟晶岩中。这个地区发育着许多花岗岩和花岗伟晶岩。伟晶岩可分为:(1)分异不好的伟晶岩,无矿化;(2)含Be伟晶岩,分带较好,见绿柱石;(3)含Be-Nb-Ta... 详细信息

在西非的象牙海岸Issia地区分布着许多铌钽矿床,包括原生矿和砂矿。原生矿产在分带很好的伟晶岩中。这个地区发育着许多花岗岩和花岗伟晶岩。伟晶岩可分为:(1)分异不好的伟晶岩,无矿化;(2)含Be伟晶岩,分带较好,见绿柱石;(3)含Be-Nb-Ta的伟晶岩,分带很好,是矿体;(4)Be-Nb-Ta-Li伟晶岩,分带很好,是矿体。除了10多个原生矿外,还有许多砂矿。砂矿有两种类型:一种近原生矿的坡积砂矿,另一种是经河流冲刷搬运后的冲积砂矿。我们选择了Etienne-Meguhe砂矿作为近原生矿的坡积砂矿的代表,Bemadi矿作为河流冲积型的砂矿的代表,对这两种类型的砂矿的风化、搬运、沉积机理进行了比较研究。研究发现不同的搬运距离和搬运模式对铌钽砂矿的主要矿物——铌钽铁矿的化学性质没有什么影响,而其物理形态则发生了变化。坡积型砂矿的铌钽铁矿常与石英、长石等矿物连生,其颗粒大小与原生的Nb-Ta伟晶岩中的铌钽铁矿一致;经河流冲积而形成的砂矿中,铌钽铁矿颗粒变小、轮廓变得圆滑,几乎无连生矿物,但矿体集中,常在河流的冲积扇中分布,易开采。

关键词：铌钽砂矿坡积砂矿冲积砂矿象牙海岸

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Defining failure of endoluminal biliary drainage in the era of endoscopic ultrasound and lumen apposing metal stents

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World Journal of Gastroenterology 2024年第29期30卷 3534-3537页

作者： Faisal S Ali Sushovan guha Department of Gastroenterology Hepatologyand NutritionUniversity of Texas Health Science Center at HoustonHustonTX 77054United States Department of Clinical Sciences Tilman J.Fertitta Family College of MedicineUniversity of HoustonHoustonTX 77204United States

The role of endoscopy in pathologies of the bile duct and gallbladder has seen notable advancements over the past two *** advancements in stent technology,such as the development of lumen-apposing metal stents,and adoption of endoscopic ultrasound and electrosurgical principles in therapeutic endoscopy,what was once considered endoscopic failure has transformed into failure of an approach that could be salvaged by a second-or third-line endoscopic *** of these advancements in routine patient care will require formal training and multidisciplinary acceptance of established techniques and collaboration for advancement of experimental techniques to generate robust evidence that can be utilized to serve patients to the best of our ability.

关键词： Endoscopic ultrasound Guided biliary drainage Gallbladder Biliary obstruction Lumen-apposing metal stent

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Increase in Organochlorine Contaminant Levels in Major Water Sources of the United States in Response to the Coronavirus Pandemic

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Journal of Biosciences and Medicines 2024年第5期12卷 111-143页

作者： Wendy Wilburn Sujata guha Ryan Beni Department of Biological Sciences Tennessee State University Nashville TN USA Department of Chemistry Tennessee State University Nashville TN USA

Organochlorine contaminants, such as triclosan (TCS), are present in major water sources across the United States. These antimicrobial compounds are widely used as multipurpose ingredients in everyday consumer products. They can be ingested or absorbed through the skin and are found in human blood, breast milk, and urine samples. Studies have shown that the increased use of antimicrobial agents leads to their presence and persistence in the ecosystem, particularly in soil and watersheds. Many studies have highlighted emerging concerns associated with the overuse of TCS, including dermal irritations, a higher incidence of antibacterial-related allergies, microbial resistance, disruptions in the endocrine system, altered thyroid hormone activity, metabolism, and tumor metastasis and growth. Organochlorine contaminant exposures play a role in inflammatory responsiveness, and any unwarranted innate response could lead to adverse outcomes. The capacity of TCS and other organochlorine contaminants to induce inflammation, resulting in persistent and chronic inflammation, is linked to various pathologies, such as cardiovascular disease and several types of cancers. Chronic inflammation presents a severe consequence of exposure to these antimicrobial agents, as any changes could result in the loss of immune competence. Organochlorine contaminant levels were established by the United States Environmental Protection Agency (EPA) in 2019-2020 and have consistently increased in response to the novel coronavirus (nCoV) (COVID-19) pandemic. Our previous research examined the overuse of products containing triclosan (TCS), which led to an increase in total trihalomethane (TTHM) levels affecting the quality of our water supply. We also investigated the impact of the FDA ban that now requires pre-market approval. To comprehend the consequences of excessive antimicrobial use on water quality, we conducted an analysis of the levels of total trichloromethane (chloroform), a byproduct of

关键词： Organochlorine Contaminants Triclosan Trihalomethane Chloroform Water Quality

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