冀东兴隆-宽城地区硫铁矿床中黄铁矿叠层石的生物成矿作用

通过对冀东兴隆－宽城地区多金属硫铁矿订中贡铁矿叠层石有机地球化学及生物标志化合物的研究。发现这些叠层石中ｎＣ１５－ｎＣ２５规则类异戊二稀烷烃含量丰富,植烷（Ｐｈ）、姥鲛烷（Ｐｒ）含量较高．饱和烃／芳烃之比为１．２～１．９,有机质类型属低等生物为主的腐泥型,有机成熟度较高。研究结果表明黄铁矿叠层石是原生藻沉积构造。它们是在较封闭还原环境中,海底热水喷口附近嗜热藻细菌大量繁殖,并对喷气作用带来的成矿物     

冀东高板河中元古代硫铁矿叠层石结构特征及其成因

冀东高板河中元古代多金属硫化物矿床呈层状和透镜状与容矿岩石整合产出,其中发育大量各种类型的硫铁矿叠层石,呈中、小型丘堆状分布在多金属硫化物矿床中。通过对其进行形态学及显微结构研究和激光拉曼光谱测试表明,高板河硫铁矿叠层石的形成环境明显不同于普通藻叠层石的生长环境,形成于局部强封闭还原的半深海环境中,远离透光带,是海底黑烟囱周围嗜热微生物周期性生长形成的原生微生物沉积构造。硫铁矿叠层石的形态与其所处的环境以及微生物的种类有关。嗜热微生物对于黄铁矿矿床的形成具有重要的促进作用。     

Pyritic shales and microbial mats: Significant factors in the genesis of stratiform Pb-Zn deposits of the Proterozoic?

Extensive horizons of pyritic shale occur in Mid-Proterozoic sediments of the eastern Belt basin, Montana, U.S.A. These pyritic shales are of striped appearance. Laminated pyrite beds alternate with nonpyritic shale beds. Laminated pyrite beds have wavycrinkly internal laminae and are interpreted as mineralized microbial mats. Pyrite is essentially the only sulfide mineral in these shales. Pyritic shale horizons occur along the basin margins, and it is feasible that colloidal iron was introduced by rivers into basin marginal lagoons and then incorporated into microbial mats and reduced to pyrite. The pyritic shales in the Newland Formation show great similarity to those that host the Pb-Zn deposits of Mt. Isa and McArthur River. It is suggested that pyritic shales of this kind are relatively common in Mid-Proterozoic shales, and that the processes that led to the occasional formation of Pb-Zn ore bodies in these shales are not related to those that formed the pyritic shales themselves.     

低温成矿系列中生物有机质的矿床学意义

在低温热液型矿床的形成过程中, 生物和有机质发挥了重要的成矿作用.这种作用可以归纳为直接和间接两种.生物及有机质直接参与成矿作用的意义在于: 在沉积岩主岩的同生沉积阶段形成矿源层, 在成矿物质活化迁移过程中形成含矿流体, 在成矿元素的沉淀阶段富集形成矿床; 生物及有机质间接成矿意义是指有机质的成熟演变作用及其产物可以揭示成矿过程, 反映低温热液成矿机理和成矿条件.      

黄铁矿叠层石丘堆式沉积与块状硫化物的富集作用

通过对黄铁矿叠层石组构、成分、微量元素、硫同位素、分子生物标志物与产出的构造环境背景的研究可知 ,黄铁矿叠层石的形成是通过沿同生断裂上升喷溢入海的热流体长期脉动作用 ,构成栖息在热水喷口与热液丘堤周围的嗜热微生物群落生存的食物链基础 ,使嗜热微生物围绕热水喷口繁殖的结果。沿同生断裂上升喷溢入海的热流体长期脉动过程中不断吸附、富集成矿元素 ,并将海水中的硫酸盐还原为H2 S。微生物吸附的Fe2 + 与S2 -作用 ,形成黄铁矿叠层石。微生物群落在热水喷口与丘堤附近不均衡发展 ,产生了成矿带内块状硫化物矿床中的黄铁矿叠层石丘堆。这种黄铁矿叠层石丘堆体是寻找富矿的显著标志 ,具有重要的成因与找矿意义     

Occurrence and distribution of sulfur in peat-forming environments of southern Florida

Cores and surface samples of peats from the Everglades—Mangrove region of Southern Florida were analyzed for total sulfur and pyritic sulfur. These values were compared with the petrographic-botanical components of the peats as determined from point-counts of oriented microtome sections. Pyrite occurs as individual euhedral crystals, loosely packed framboids, and lenses or crusts of minute crystals. Framboids and minute crystals are often associated with organic matter and sometimes with bacteria and fungi. Pyrite tends to selectively occur in void spaces in or between peat tissues. In samples containing very small amounts of pyrite, framboidal pyrite is the prevalent form.Marine to brackish peats contain the highest pyrite and total sulfur contents, with brackish peats generally containing more pyrite than marine peats. Pyrite tends to be lower in all peats within 30 cm of the surface, whether marine or brackish.Burial of freshwater peats beneath marine or brackish peats tends to increase the total sulfur and pyritic sulfur in the underlying peats. Burial beneath brackish-water, clay-rich deposits (such as splays) tends to increase total sulfur and pyritic sulfur in the underlying deposits more than burial beneath less clay-rich deposits.     

兰坪-思茅盆地与泰国呵叻盆地含钾卤水同源性研究──兼论该区找钾有利层位和地区

我国兰坪 思茅盆地与泰国呵叻盆地同处在一个大地构造带，成矿时代和层位相同，析盐矿物组合类似，母液卤水组成具同源性，兰坪 思茅盆地卤水是自呵叻盆地向北迁移所致；析盐组合变化符合卤水从北向南逐渐浓缩的趋势。呵叻盆地下、中、上盐组所显示的三次成盐旋回中，中盐组在兰坪 思茅坳陷带均有沉积，下盐组在思茅盆地也有沉积，推断该组沉积期卤水浓缩程度低于呵叻盆地，矿石类型将优于呵叻盆地。我国境内找矿有利层位应为下泥砾盐层（相当呵叻下盐组）。     

Hydrothermal pyrite chimneys from the Ballynoe baryte deposit,Silvermines, County Tipperary,Ireland

We report the discovery of pyrite tubes 0.1 to 20mm in diameter in the Ballynoe sedimentary baryte deposit. Well developed tubes comprise concentric layers of pyrite of contrasting crystal sizes 0.05 to 1 mm thick. An outer rim of crystalline baryte 10mm thick commonly coats the tubes where these are not touching. The central canals contain myriad pyrite framboids. These tubes have characteristics in common with the chimney spires found on the East Pacific Rise at 21°N from which metal bearing solutions issue at temperatures of up to 380±30°C. Their presence carries the implication that the baryte deposit was not a distal facies of the Silvermines sedimentary pyritic zinc and lead ore, but was produced from local hydrothermal exhalations, though in a shallower part of the basin than the coeval sulphide deposits which had their own feeders. Some epigenetic mineralization may be awaiting discovery beneath the feeder sites at Ballynoe.     

A demonstration of an affinity between pyrite and organic matter in a hydrothermal setting

One of the key-principles of the iron-sulphur world theory is to bring organic molecules close enough to interact with each other, using the surface of pyrite as a substrate in a hydrothermal setting. The present paper explores the relationship of pyrite and organic matter in a hydrothermal setting from the geological record; in hydrothermal calcite veins from Carboniferous limestones in central Ireland. Here, the organic matter is accumulated as coatings around, and through, pyrite grains. Most of the pyrite grains are euhedral-subhedral crystals, ranging in size from ca 0.1-0.5 mm in diameter, and they are scattered throughout the matrix of the vein calcite. The organic matter was deposited from a hydrothermal fluid at a temperature of at least 200°C, and gives a Raman signature of disordered carbon. This study points to an example from a hydrothermal setting in the geological record, demonstrating that pyrite can have a high potential for the concentration and accumulation of organic materials.     

西天山金、铜矿地质特征简述

西天山是我国古生代造山带重要的金、铜矿成矿单元之一,具有Au、Cu地球化学场.各种地球物理场也显示具有良好的金、铜矿成矿地质背景.金、铜矿主要生成于海西期的构造岩浆地质热事件中,形成了浅成低温热液型和韧性剪切带型金矿以及海底火山喷气热水沉积型、矽卡岩型、斑岩型、陆相火山热液充填型铜矿.可划分出赛里木铜金成矿带、吐拉苏也里莫墩金成矿带、察布查尔铜成矿带及胜利达坂金成矿带.主要矿床有阿希金矿、望峰金矿、喇嘛苏铜矿和预须开普台铜矿.     

湘西南中、上泥盆统礁特征及其找矿意义

作者提出了一个较完善的生物礁定义。在湘西南洞口—城步确定了十个生物礁;列举了典型礁相剖面并阐述了礁体特征;提出六种生物礁成矿作用。环礁内的城步铺头黄铁矿床成因类型,属于礁控半闭塞泻湖沉积矿床。后来（1979—1980）鉴于这类矿床的独特成矿作用和巨大经济价值,提出礁控成矿论、礁控矿床和生物数学地质等概念来指导找矿。     

海底黑烟囱的识别研究及其科学意义

现代海底黑烟囱广泛出现于大洋中脊、弧后盆地、浅海及大陆裂谷等环境,形成巨大规模的块状硫化物,并且在黑烟囱周围发现了化学自养细菌。海底硫化物黑烟囱具有明显的柱状-锥状构造形态,常保留通道构造,矿物同心圈状分带明显。黑烟囱的形成涉及热液流体与海水相互作用,外壁快速沉淀及通道内部硫化物结晶等过程。深部岩浆热源、热液沿裂隙集中流动和持续喷发,有利于形成大规模黑烟囱构造。海底硫化物丘体的钻探及其与地史时期块状硫化物的对比研究表明,它们具有相似的内部构造和矿床分带特征。黑烟囱的生长、垮塌以及丘体内部角砾化、交代、重结晶作用,有助于大规模矿床的形成。最后,在块状硫化物中寻找黑烟囱残片的研究,对于探讨成矿过程与早期生命活动具有重要意义。     

冀东地区元古宙多金属硫铁矿矿床地质及其成矿作用

通过对冀东地区元古宙多金属硫铁矿床成矿构造环境背景、喷气沉积岩地球化学以及矿床中大量矿化嗜热微生物的发现与研究 ,以及采用分子生物学对沉积记录中的生物标志物的研究。得知冀东地区多金属硫铁矿的形成主要由海底喷气沉积与嗜热微生物富集成矿作用所致。运用海底喷气成矿热流体活动 嗜热微生物吸附与新陈代谢 多金属硫铁矿床形成的成矿理论 ,指导该区硫铁矿找矿工作已见成效。     

Pyrite deformation in stratiform lead-zinc deposits of the Canadian Cordillera

Pyrite textures in five stratiform lead-zinc deposits from lower to upper greenschist facies environment of the Canadian Cordillera are described and discussed in terms of deposition/early diagenesis, deformation, metamorphism and hydrothermal alteration processes. Overgrowth is an important process during both diagenesis and deformation. Diagenetic and deformational overgrowths can be distinguished. Diffusive mass transfer, involving pressure solution and oriented overgrowth of pyrite is the main deformation mechanism in pyrite deposits at low metamorphic grades. Although diffusive mass transfer favours fine-grained mineral aggregates, its effect on coarse pyrite grains has also been identified. Ore minerals dissolved by pressure solution may be transported, with the assistance of pore fluids within fractures and grain boundaries, over distances significantly greater than the scale of individual grains to give a range of pressure solution/overgrowth textures. The textural modification of pyritic ores from the early stages of diagnesis, through metamorphism and deformation, to post deformation thermal annealing, has important implications for the distribution of trace elements and isotopic compositions in pyritic ores.     

城步铺头黄铁矿床再研究

位于湖南中部的城步铺头黄铁矿床,是产于泥盆系基维特阶的层状矿床,1984年作者在本刊报导过这个矿床的沉积环境。根据新的资料,再次对它的成因进行研究。该矿床位于华南古大陆边缘裂谷系的北东向深水盆地中,含矿岩系由暗色的硅质岩-泥灰岩组成,矿体呈层状整合产出,以黄铁矿为主,硫同位素以富含32S为特点（δ34S＝-17．4‰～-30.10‰）。含矿岩系及矿石中,有机质含量较高（3％～5％）,有机质类型为腐殖-腐泥混合类型,成熟度较高。矿石具致密块状及条带状构造,由大量草莓状黄铁矿组成,它们主要出现在致密块状矿石中。矿石及含矿围岩的稀土元素、微量元素组成,与现代大洋裂谷或隆起区中的热液沉积物的特征相似,表明它们具有相同的来源和成因,应属海底热液喷流沉积矿床,大量存在的有机质,对于矿床的形成也起了重要的作用。     

Mineralization of a Proterozoic Sulfide Black Smoker Chimney and Thermophilous Microorganisms in Eastern Hebei, China

A sulfide black smoker chimney exists in the Gaobanhe seabed exhalation massive sulfide deposit in the Xingiong-Kuancheng secondary fault basin of the Proterozoic Yaniiao rift trough in Hebei Province, taking the shape of mounds, individually about 2-3 cm high. Abundant fossils of thermophilous bacteria and algae in perfect preservation are found in the ore surrounding the black smoker chimney. Scanning electron microscopy （SEM） and molecular biomarker studies on the microorganismai ore fabric show that the microorganism in the sulfide ore is in fact a sedimentary product of probiotic bacteria and algae. In the special food chain based on black smoker chimney at ancient seabed- thermophilous bacteria, the thermophilous bacteria and algae reproduce in large quantity. Intermittently erupting of fluid from the chimney creats conditions for formation of sulfide deposit. In the process of exhalation action of hot fluid, thermophilous bacteria and algae grow and reproduce around the sulfide black smoker chimney, absorbing mineralizing substances brought by the fluid. Massive sulfide deposits are formed in this process of absorption of seabed black smoker chimney exhalation-mineralizing fluid pulsation-thermophilous microorganism.     

沁水盆地晚古生代煤中硫的地球化学特征及其对有害微量元素富集的影响

煤中硫是多种有害微量元素的重要载体。基于形态硫分析、电感耦合等离子质谱及X射线衍射等方法分析沁水盆地晚古生代煤中硫和有害微量元素的分布规律,探讨了煤中硫对有害微量元素富集的影响,运用带能谱的扫描电镜和光学显微镜划分煤中硫化物的微观赋存特征。结果表明,沁水盆地煤中硫整体上以有机硫为主,平均占全硫的78%,只有在太原组个别高硫煤中以黄铁矿硫为占优势。显微镜和扫描电镜下可识别出煤中黄铁矿的微观赋存状态包括莓球状、薄膜状、晶粒状、结核状、团窝状黄铁矿和细粒黄铁矿集合体,白铁矿的微观赋存特征包括聚片状、板状和矛头状白铁矿,部分白铁矿与黄铁矿共生。沁水盆地煤中有害微量元素含量整体较低,黄铁矿是有害微量元素As、Se和Hg的重要载体,而有机硫决定了煤中U的富集。研究认为,成煤时期海水对泥炭沼泽的影响导致太原组煤中全硫和黄铁矿硫较高,太原组煤中硫的来源具有多样性,煤中黄铁矿具有多阶段演化的特点。     

http://www.sciencedirect.com/science/article/pii/S1674987111000806

Zoned tourmaline（schorl-dravite） in the matrix of hydrothermal explosive breccia and ore veins in gold deposits,Chita region.Eastern Transbaikalia.Russia,are associated with Na- and K-rich porphyry-type subvolcanic intrusives.δ¹⁸O values of tourmaline from three gold deposits（Darasun. Talatui,Teremkinskoye） are +8.3‰,+7.6‰,and +6.0‰and calculatedδ¹⁸O values of fluids responsible for the tourmalinization are +7.3‰,+7.7‰,and +4.2‰,respectively.These data imply an igneous fluid source,except at the Teremkin deposit where mixing with meteoric water is indicated.Wide ranges of Fe³⁺/Fe_tot,and the presence of vacancies characterize the Darasun deposit tourmaline indicating wide ranges of f（O₂） and pH of mineralizing fluids.Initial stage tourmalines from the gold deposits of the Darasun ore district are dravite or high mg schorl.Second stage tourmaline is characterized by oscillatory zoning but with Fe generally increasing towards crystal rims indicating decreasing temperature.Third stage tourmaline formed unzoned crystals with x_Mg（mole fraction of Mg） close to that of the hrst stage tourmaline,due to a close association with pyrite and arsenopyrite.From Fe³⁺/Fe_tot values,chemical composition and crystallization temperatures.logf（O₂） of mineralizing fluids ranged from ca.—25 to—20. much higher than for the gold-bearing beresite—listvenite association,indicating that tourmalinization was not related to gold mineralization.     

"Brown Ore" from the Fukasawa Kuroko Deposits, Northeast Japan: Its Characteristics and Formation Process

Abstract: Brown–colored sulfide ore (brown ore) occurs in the easternmost part of the Tsunokakezawa No. 1 orebody of the Fukasawa kuroko-type deposits, northern Honshu, Japan. As this type of ores also occur in the marginal or uppermost part of several other kuroko deposits in Japan, the formation of brown ore appears to be repeated in the process of kuroko formation. The brown ore is characterized by its higher Ag concentration (up to around 2000 g/t) than ordinary black ore (Zn–Pb ore) of volcanogenic massive sulfide deposits. The brown ore from the Fukasawa deposits can be divided into following three ore types based on its texture and mineral composition: pyritic brown ore, principal brown ore and “diseased” brown ore. Primary precipitation textures such as framboidal– and colloform-textures and compositional zoning within sulfide grains are significant in the brown ores. This seems to be due to lack of overprinting high temperature mineralization resulting in preservation of primary features. The Ag-Au mineralization is widely observed within the brown ores. Silver and gold are especially concentrated in the barite veinlets in the principal brown ore, which are supposed to be fillings of conduit of hydrothermal solution precipitated in the latest stage of hydrothermal activity. This mineralization seems to occur at waning stage of brown ore formation by ore solution at a lower temperature (around 250°C) than that of main part of brown ore (around 270°C). Relatively low fluid temperature and contribution of oxic ambient seawater may be responsible for the development of the Ag-Au mineralization in the brown ore. The occurrence of framboidal-rich pyritic brown ore having negative δ³⁴S values (less than –10%) and filamentous texture of sphalerite, seeming remnant of bacteria, indicate the presence of intensive microbial activity in the hydrothermal area for brown ore formation. Formation environment of each ore type of the brown ore is supposed to be as follows: Pyritic brown ore is likely to have formed on the sea-floor around redox boundary at temperature (around 240°C) lower than ordinary black ore. Principal brown ore seems to have been formed beneath the shell of the pyritic brown ore at temperature around 270°C. Footwall of the brown ore is disseminated tuff breccia corresponding to feeder zone of hydrothermal fluid. Overprinting chalcopyrite mineralization is not observed in the brown ore except in limited part of “diseased” ore, which occurs just above the disseminated tuff breccia. Based on the features distinct from the ordinary black ore, the brown ore can be regarded as a product in the marginal part of submarine hydrothermal system, where temperature and flow rate of hydrothermal solution was relatively low and microbial activity was intensive. The brown ore seems to well preserve its primary features after its deposition and might show the initial feature of some part of the ordinary stratiform black ore.     

广西热水沉积成矿作用的基本特征

详细叙述了广西热水沉积型矿床的成矿时代、空间分布和控矿环境，指出主要的矿产种类有锡、铅、锌、锑、汞、金、铜、钨、锰、铁、磷、重晶石及黄铁矿。其成矿时代为早元古代、晚元古代、早古生代、晚古生代及中生代，以泥盆纪为最重要的成矿时代；矿床在空间上主要分为桂北晚古生代裂陷锡-多金属成矿带及桂西南泥盆纪裂陷锰-重晶石-黄铁矿成矿带，次为桂东南早古生代裂陷铅-锌-多金属成矿带、桂中-桂北泥盆纪走滑断陷铅-锌-重晶石黄铁矿成矿带及桂西北早中三叠世裂陷金矿成矿带，此外还有桂北-桂东元古宙裂陷铁-锡-重晶石成矿带；控矿构造环境为裂谷构造，成矿受裂陷槽及区域性同沉积断裂控制；控矿沉积环境主要为台沟相带，次为局限-半局限台地相带、开阔台地相带、生物礁相带及海槽相带。并指出广西的热水沉积岩主要有硅质岩、电气石岩、层状矽卡岩及重晶石岩。