内蒙古巴音戈壁盆地塔木素碱矿Na-碳酸盐成因模式

内蒙古巴音戈壁盆地哈日凹陷下白垩统巴音戈壁组沉积时期为典型的碳酸盐型碱湖,盆地咸化过程中发育大量的Na-碳酸盐类矿物.通过对巴音戈壁组碱矿层中似层状、斑点状和脉状Na-碳酸盐矿物开展了电子探针、X衍射、碳氧同位素和激光拉曼光谱等分析,结果表明碱矿层中Na-碳酸盐矿物主要为天然碱、苏打石、碳钠钙石、碳钠镁石和磷碳镁钠石.除Na-碳酸盐外,岩石中含少量黄铁矿、钠型菱沸石、硅硼钠石和钠长石等热液矿物.碳、氧同位素研究结果表明巴音戈壁盆地下白垩统碱矿层形成于封闭的碱湖环境,碳酸盐矿物形成温度为34～80℃（平均值57℃）,受热水喷流沉积作用和蒸发作用双重控制,碱矿层中硅酸盐矿物首先形成,然后形成白云石和方解石,在Ca2+、Mg2+消耗殆尽后,天然碱和苏打石发生沉淀,由于热水带来充足的Na+,前期形成白云石和方解石发生交代作用形成碳钠钙石和碳钠镁石.在矿物学和地球化学综合分析基础上,建立了热水喷流和蒸发沉积双重控制下的碱湖Na-碳酸盐岩沉积模式,以期为碱矿勘查提供新的思路.     

新疆且末县布拉克铜矿地质特征及成因分析

新疆且末县布拉克铜矿位于吐拉盆地西南缘,为典型的陆相砂砾岩型铜矿床.矿体呈层状产出于白垩纪红色碎屑岩建造内的浅色砂砾岩层中.矿石由石英、长石等矿物晶屑、安山岩、玄武岩、流纹岩等岩石碎屑、孔雀石、褐铁矿等金属矿物填隙物及碳酸盐、泥质物等胶结物组成.吐拉断陷盆地西南缘白垩系砂砾岩层广泛分布,该矿床的发现与其成矿特征对该地区...     

中国油页岩型天然碱矿床成因研究

油页岩型天然碱矿床是中国天然碱矿床重要的成因类型，成矿大地构造背景为活动性构造带，成矿环境为干旱气候条件下的深水盐湖。钠主要源于深部油田的热卤水，碳主要源于剥蚀区碳酸盐岩。成矿作用为混卤化学沉积作用：源于深部油田的富钠热卤水与地表富碳常温卤水混合导致碱矿物析出成矿。找矿方向：南阳次级盆地东端、吴城盆地东南部及构造活动带内的油页岩分布区。     

宁夏—内蒙阿拉善左旗陆相膏盐矿床的地质特征及其形成条件

一、概况渐新世陆相膏盐盆地在宁夏及其毗邻内蒙阿拉善左旗广泛分布,其中赋存有我国较罕见的特大型陆相石膏矿床。在渐新世贺兰山—香山古陆呈北东—南西向纵贯于该区中部,将其分隔为南北两个石膏蕴矿区:贺兰山—香山以北为阿拉善左旗石膏蕴矿区,由吉兰泰—图兰泰盆地组成,该盆地自阿左旗豪斯布尔都南达腾格里沙漠南缘,包括苏海图岗岗免及五棵水弓子梁大型石膏矿床,主要石膏矿层位为下渐新统查干布拉格组;贺兰山—香山以南为宁南石膏蕴矿区,西自     

土耳其的天然碱资源

天然碱有两种成因类型.一是产于现代盐湖中的天然碱矿床;二是形成于古代盐湖埋藏于地下的古代天然碱矿床.此类型矿床世界上发现的不多,如土耳其安卡拉盆地贝帕扎里天然碱矿床.     

锡铁山铅锌矿床碳酸盐型锌矿石及其利用问题

锡铁山铅锌矿床是50年代末期探明的大型块状硫化物矿床。80年代初开始矿山建设,并计划在“七五”期间进行采选。在此期间,西安地质矿产研究所在《锡铁山铅锌矿床类型与地质特征》课题研究中,发现有碳酸盐型锌矿石,继之青海地矿局中心实验室、长沙矿冶研究院、北京矿冶研究总院,西北矿冶研究院先后进行了实验研究工作,充分肯定该碳酸盐型锌矿石的矿物属Zn、Fe类质同象菱锌铁矿—菱铁锌矿系列矿物。在此基础上,笔者拟就该碳酸盐型锌矿石在矿床中的分布、产状、成分特征、成因以及工业利用问题谈些肤浅看法。     

丝钠铝石是一种应当重视的含铝矿物

近年来的新资料表明,铝的碳酸盐矿物——丝钠铝石,是一种分布广、储量大、未来有前景的铝工业原料.美国科罗拉多州皮恰恩斯河盆地的丝钠铝石总储量约245亿吨(合85亿吨氧化铝),是世界上规模最大的丝钠铝石矿体.该矿体产于由含石油的沥青、泥灰岩和页岩互层组成的始新世层系中.岩层内夹火山灰和天然碱(Na_2CO_3·NaHCO_3·2H_2O).丝钠铝石呈浸染状、透镜状和断续的脉状、均匀散布的晶体及其集合体产出.含矿层厚91m,面积41400km~2,丝钠铝石平均含量12.3%,最高达25%,与重碳酸盐层共生,并伴生少量三水铝石.对从该区提取丝钠铝石、重碳酸盐、天然碱和地沥青进行了研究.苏联喀尔巴阡和顿巴斯的丝钠铝石赋存于汞矿矿化区.白俄罗斯的丝钠铝石产于下石炭统土尔聂依组铝土矿层中.富含丝钠铝石的样品,含(%)Al_2O_3-31,SiO_2     

老挝万象海夏峰钾盐矿床水不溶矿物及其对沉积环境的约束

【研究目的】老挝钾盐矿床是世界上重要的钾盐矿床之一,开展该矿床钾盐析出阶段沉积环境研究对于深入理解钾盐成矿作用具有重要意义。【研究方法】钾盐矿层中的水不溶矿物比可溶盐类矿物保存了更多的原始信息,是研究成矿卤水演化的重要载体。本文以老挝万象盆地海夏峰矿区ZK16钻孔为研究对象,利用镜下鉴定、XRD及SEM等方法对该钻孔钾盐矿层的水不溶矿物开展了系统研究。【研究结果】分析结果表明,水不溶物中的主要矿物为硬石膏、方硼石、水氯硼钙石、石英、白云石、菱镁矿、方解石、白云母等,其中以硬石膏、方硼石是主要的水不溶矿物。自生石英及碎屑白云母的存在及其分布特征指示了钾盐在沉积过程中不同程度地受到陆相水体的影响。【结论】综合研究揭示,研究区钾盐沉积可以分为波动沉积、浅水沉积、稳定沉积和改造作用等4个不同阶段。     

云南楚雄前陆盆地晚三叠世沉积建造及盆地演化

根据沉积建造的类型、系列和体态认为楚雄盆地在晚三叠世经历了３个明显的发育阶段：第一阶段为早期聚敛碰撞阶段,发育了黑色页岩建造和碳酸盐复理石建造;第二阶段为构造相对静止期,发育了火山复理石建造和陆源复理石建造;第三阶段为盆地充填阶段,发育了海相磨拉石建造和陆相磨拉石建造。３个阶段中的沉积建造属于次稳定型和非稳定型两大类。     

青海察尔汗盐湖别勒滩区段杂卤石成因及其成钾指示意义

别勒滩区段位于青海察尔汗盐湖西部,前人认为察尔汗盐湖固体钾盐矿物以光卤石为主,在别勒滩区段西部发现有杂卤石,但并未引起足够重视,对杂卤石成因未做详细研究。本文通过对别勒区段七个钻孔样品的矿物鉴定及地球化学分析,发现别勒滩区段杂卤石以原生和准同生交代方式赋存,且以后者为主,多交代石膏等硫酸盐矿物产出,少量出现交代石盐现象。杂卤石主要分布于别勒滩中西部地区,整个别勒滩区段自西向东出现了以杂卤石为主渐变为以钾石盐—光卤石为主的分布规律。结合别勒滩区段晶间卤水的补给条件,研究认为别勒滩区段杂卤石形成是涩聂湖硫酸镁亚型湖水与先期形成的盐类矿物发生交代反应的结果。别勒滩地区杂卤石作为典型的陆相成因,对研究海相蒸发岩矿床中普遍存在的杂卤石成因具有一定的对比借鉴意义,海相蒸发岩矿床中的杂卤石可能是盆地形成的内陆盐湖湖水与早期沉积的盐类矿物发生交代反应形成,对寻找海相钾盐有一定的指示意义。     

江西41 4含钽、铌钠长石化花岗岩风化壳中三水铝石的发现及其成因研究

The Wucheng trona deposit, one of the rare ancient trona deposits in the world, is genetically of typical terrestrial facies carbonate sediments of brine lake. Contained in an Eogene block basin composed of terrigenous clastic-evaporite rocks some 2400 m in thickness, it occurs 650 to over 900 m beneath the earth's surface in the form of multilayers, the lower part being pure trona beds while the upper part consisting of trona beds interbedded with halite streaks. Saline minerals are trona and to a much less amount, halite and nahcalite, associated with such minerals as shortite and northupite. Mirabilite, a rather common mineral in the carbonate salt lake, has not yet been found here. The unusually developed sedimentary cyclothem of the host rock, predo-minantly argillaceous dolomite- kuchersite- (halite-bearing) trona, makes up a most striking feature of this deposit, and the trona bed lies invariably on the kuchersite-dolomite facies. Although belonging to one of the minerogenetic series of saline deposit, the trona deposit, instead of being simply a product of the evaporation of brine, has its specific mineral-forming conditions and sedimentation mechanism. Trona is a typical product of the terrestrial facies carbonate lake. lts formation, therefore, requires the persistent supply of large quantities of Na-rich carbonate type water which, being actually surface water or ground water circulating through the metamorphic and igneous rocks at the periphery of the basin, constitutes an indispensable factor in the sedimentation of trona by its concentration and evaporation. Besides, the coicentration of CO_{8<.sub>^-2 and HCO8^- in the solution is related to the partial pressure of CO2. Only when sufficient CO2 is unceasingly supplied can nahcalite and trona be precipitated. CO2, in turn, depends on the presence of large amounts of organism for its formation. These factors are prerequisites for the precipitation of the trona deposit, making it distinctly different from other saline deposits. Other formation conditions of the Wucheng trona deposit, such as the existence of a closed basin controlled by tectonics, the alternate arid and semiarid climates, are quite analogous to those of other saline deposits. Some controversial problems concerning this kind of deposit are also put for ward in this paper for further investigation, including the feasibility of taking the abundance of sulfate minerals as a criterion of distinguishing ancient tronas from recent ones, the influence of material resources and climate conditions upon the variation of ore types, and the origin of the highly-concentrated sodium brine in areas adjacent to the Wucheng deposit.}     

中国石盐矿床之分类

中国石盐矿产资源丰富 ,不同矿床产出地质背景、成矿条件、时空分布特征、物质组成等不尽相同。按其物相特征划分为固相矿床和液相 (卤水 )矿床两大类。前者根据产出时代及岩相特征划分为第四纪盐湖型、中新生代陆相碎屑岩型和前中生代 (含三叠纪 )海相碳酸盐型等矿床类型 ,根据不同的矿石建造还可作进一步划分。后者又可分为不同时代的地表及地下卤水矿床类型。成岩盆地受构造控制明显。有计划地综合开发利用我国盐类矿产资源有重要意义。     

Phase Chemistry Study of the Zabuye Salt Lake Brine: Isothermal Evaporation at 15°C and 25°C

Zabuye Salt Lake in Tibet, China is a carbonate-type salt lake, which has some unique characteristics that make it different from other types of salt lakes. The lake is at the latter period in its evolution and contains liquid and solid resources. Its brine is rich in Li, B, K and other useful minor elements that are of great economic value. We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15°C and 25°C. The crystallization sequence of the primary salts from the brine at 25°C is halite (NaCl) → aphthitalite (3K2SO4·Na2SO4) → zabuyelite (Li2CO3)→ trona (Na2CO3·NaHCO3·2H2O) → thermonatrite (Na2CO3·H2O) → sylvite (KCl), while the sequence is halite (NaCl) → sylvite (KCl) → trona (Na2CO3·NaHCO3·2H2O) → zabuyelite (Li2CO3) → thermonatrite (Na2CO3·H2O) → aphthitalite (3K2SO4·Na2SO4) at 15°C. They are in accordance with the metastable phase diagram of the Na+, K+-Cl?, CO32?, SO42?-H2O quinary system at 25°C, except for Na2CO3·7H2O which is replaced by trona and thermonatrite. In the 25°C experiment, zabuyelite (Li2CO3) was precipitated in the early stage because Li2CO3 is supersaturated in the brine at 25°C, in contrast with that at 15°C, it precipitated in the later stage. Potash was precipitated in the middle and late stages in both experiments, while boron was concentrated in the early and middle stages and precipitated in the late stage.     

腾格里地区盐湖的盐类沉积特征

腾格里沙漠122个盐湖分为石盐、石盐-芒硝、石盐-白钠镁矾及芒硝(石膏)4种类型。盐湖含盐系厚度一般4～9m,总体呈现下部为含盐碎屑沉积,上部以盐类沉积为主,构成储卤层,卤水赋存其中,由湖岸至湖心储卤层厚度增长。含卤层理渐小,卤水含KCl渐高。盐湖中矿物主要为碳酸盐矿物,以芒硝、石膏为主的硫酸盐矿物、石盐以及粘土矿物。盐湖卤水以晶间卤水为主。许多卤水含K+大于2g/L。K+含量最高的红盐池,平均含量达19.14g/L。对钾矿而言,在盐湖分布相对集中地区,有一定的综合开发利用前景。     

An explanation for the varves of the Castile evaporites (Upper Permian), Texas and New Mexico, USA

Abstract Extraordinary sequences of conspicuous, pervasive and laterally persistent varves characterize the Castile evaporites. They occur as singlets (calcite laminae), couplets (calcite laminae interstratified with anhydrite laminae), thick couplets (calcite laminae interstratified with thin anhydrite beds) and triplets (calcite and anhydrite laminae interstratified with thin halite beds). The varves accumulated in a deep (initially ≈ 550 m), persistently stratified, saline lake surrounded by an extinct reef. The lake had formed when the reef grew across a channel between an embayment and the ocean. Although located virtually on the palaeo-equator, the lake experienced negligible meteoric influx and extreme seasonality. During the season of high relative humidity, more marine groundwater entered the lake through the permeable reef barrier than exited as reflux and, secondarily, as evaporation. Consequently, the lake level rose by up to several metres to sea level. The ‘refreshening’ decreased salinity and replenished dissolved CO₂– the critical nutrient limiting growth of indigenous phytoplankton. Algae proliferated, pH increased and CaCO₃ precipitated. It mixed with organic matter to form a thin, dark lamina. During the season of low relative humidity, tens of cubic kilometres of water evaporated from and, secondarily, leaked out through the surrounding reef. More water exited than entered, brine level fell below sea level, and salinity of the upper brine layer increased. Gypsum usually precipitated and rained onto the basin floor forming a couplet; infrequently, halite also precipitated forming a triplet. Every few thousand years, for <50 to several hundred years, the lake became unstratified during the dry season, and wind-induced overturn allowed a layer of gypsum crystals up to ≈ 2 cm high to precipitate on the basin floor. Each layer, now thin beds of anhydrite nodules and anhydrite pseudomorphs after gypsum, and an underlying lamina of CaCO₃ and admixed organic matter formed a thick couplet. The different varve types recur with a period of 1800–3000 years reflecting climatic changes on a millennial time scale.     

Studies of Quaternary saline lakes—III. Mineral,chemical, and isotopic evidence of salt solution and crystallization processes in Owens Lake,California, 1969–1971

As a consequence of the 1969–1970 flooding of normally dry Owens Lake, a 2.4-m-deep lake formed and 20% of the 2-m-thick salt bed dissolved in it. Its desiccation began August 1969, and salts started crystallizing September 1970, ending August 1971. Mineralogic, brine-composition, and stable-isotope data plus field observations showed that while the evolving brine composition established the general crystallization timetable and range of primary and secondary mineral assemblages, it was the daily, monthly, and seasonal temperature changes that controlled the details of timing and mineralogy during this depositional process. Deuterium analyses of lake brine, interstitial brine, and hydrated saline phases helped confirm the sequence of mineral crystallizations and transformations, and they documented the sources and temperatures of waters involved in the reactions.Salts first crystallized as floating rafts on the lake surface. Natron and mirabilite, salts whose solubilities decrease greatly with lowering temperatures, crystallized late at night in winter, when surface-water temperatures reached their minima; trona, nahcolite, burkeite, and halite, salts with solubilities less sensitive to temperature, crystallized during the afternoon in summer, when surface salinities reached their maxima. However, different temperatures were generally associated with crystallization (at the surface) and accumulation (on the lake floor) because short-term temperature changes were transmitted to surface and bottom waters at different rates. Consequently, even when solubilities were exceeded at the surface, salts were preserved or not as a function of bottom-water temperatures. Halite, a nearly temperature-insensitive salt, was always preserved.Monitoring the lake-brine chemistry and mineralogy of the accumulating salts shows: (1) An estimated 0.9 × 10⁶ tons of CO₂ was released to the atmosphere or consumed by the lake's biomass prior to most salt crystallization. (2) After deposition, some salts reacted in situ to form other minerals in less than one month, and all salts (except halite) decomposed or recrystallized at least once in response to seasons. (3) Warming in early 1971 caused solution of all the mirabilite and some of the natron deposited a few months earlier, a deepening of the lake (though the lake-surface lowered), and an increase in dissolved solids. (4) Phase and solubility-index data suggest that at the close of desiccation, Na₂CO₃·7H₂O, never reported as a mineral, could have been the next phase to crystallize.     

新疆罗布泊盐湖氢氧锶硫同位素地球化学及钾矿成矿物质来源

罗布泊罗北凹地第四系上部盐层中蕴藏丰富的卤水,卤水中则富含钾（ＫＣｌ平均品位为１．４０％）。文章通过对罗布泊卤水氢、氧、锶及硫同位素等分析及与塔里木盆地（河流）、柴达木盆地等地区对比研究,确定了罗布泊富钾卤水源于地表水,可能主要是塔里木盆地南北缘河流水;卤水中的硫钾等物质组分主要来源于南天山、塔里木盆地西北、西南部中新生代石膏钙芒硝石盐矿床或地层及其古代地层卤水。由于第四纪期间塔里木盆地西部抬升。     

The characteristics,formation and exploration progress of the potash deposits on the Khorat Plateau,Thailand and Laos,Southeast Asia

The giant potash deposit on the Khorat Plateau is one of the most promising targets for exploitation of potassium salts. So far, many researches and geologic survey have been conducted on the giant potash deposits. Hence, it is necessary to make an overall review on the potash deposits. The potash deposit on the Khorat Plateau was formed during the Middle to Late Cretaceous, during which seawater was enriched in Ca²⁺ and depleted in SO₄^2- compared with those of modem seawater. In addition to seawater, continental water and hydrothermal fluids could have affected the evaporite basins. The seawater was probably derived from Tethys ocean, and the brine should have evaporated to some extent before entering into the basin systems based on the evidence of absence of carbonates and unproportionate sulphate compared with chloride salts. The paleo-climate during Middle to Late Cretaceous was characterized as high temperature and extremely arid environment, which is favourable for deposition of potassium-magnesium saline minerals. The major saline minerals are of anhydrite, halite, camallite, sylvite and, tachyhydrite, with trace amounts of borates. The resources of the potash deposit on the Khorat Plateau could be approximately as much as 400×10⁹ t of camallite and 7×10⁹ t of sylvite. The evaporite sequences have been deformed and altered by postdepositinal processes, including tectonic movements and chemical alteration. Salt domes were formed in the postdepositional processes. Based on the analyses of geophysical surveys and drilling projects, high-quality sylvinite ores are commonly found at the flanks of those salt domes due to incongruent dissolution of camallite. The future potential prospecting areas for the high-quality sylvinite ores would be on the edges of the Khorat Plateau.     

Sedimentological characteristics and geochemical evolution of Nabq sabkha, Gulf of Aqaba, Sinai, Egypt

Nabq sabkha exists 16 km north of Sharm El Sheikh City occupying the low land topography in the alluvial fan zone along the coastal area, Gulf of Aqaba, Sinai, Egypt. The long axis of the sabkha trends NW–SE receiving water from two different sources: meteoric water drained from the surrounding mountainous area and seawater seepage. Field observations help to divide the area into raised beach, hill slopes, sabkha basin, and coastal area. The sabkha basin can be subdivided from its center outward into (1) basin center hypersaline lake flourished with microbial mat and precipitation of halite as rafts, cumulates, and chevrons, (2) saturated saline sand and/or mud flat zone with the extensive growth of gypsum and halite crystals growing displacively as well as different forms of petee structures, and (3) an elevated marginal dry zone with tepee structures. Mineralogical analysis reveals that quartz, halite, and gypsum are the dominant minerals with subordinate amount of aragonite, anhydrite, thenardite, and/or polyhalite. In addition, clay minerals in the mudflat zone are presented by illite and smectite, indicating derivation of soil from the surrounding basement rocks. Chemical analysis of the collected brine samples reveals alkali character in the saline lake (pH?=?7.6) and high concentrations of Na⁺ (680 meq/l), Cl^? (940 meq/l), Mg²⁺ (208 meq/l), Ca²⁺ (70 meq/l), SO ₄ ²⁺ (30 meq/l), and HCO ₃ ^? (6 meq/l). The high salinity values are due to the aridity of the area, which favors precipitation of halite. Using comparative sedimentological, chemical, and mineralogial methods between such modern and ancient evaporitic environments and by detailed field, petrographic and mineralogical studies of modern evaporite environments help to interpret paleo-depositional environments of ancient evaporites sequences still in debate.