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察尔汗盐湖赋存有硫酸镁亚型和氯化物型两种水化学类型,沉积了中国最大的液体钾镁盐矿床。为解释察尔汗盐湖卤水矿床成因,拟在别勒滩、达布逊、察尔汗和霍布逊区段选择4个剖面,剖面深度在0~7 m之间,属于全新统上含盐组的上部盐层,每隔10cm进行采样,运用XRD半定量方法分析矿物组合特征。结果表明,整个湖区矿物组合由石盐、石膏、水氯镁石和碳酸盐组成,其平均含量分别为70%、4.7%、3.4%和1%;显示其矿物组合特征简单,盐层主要沉积石盐而贫石膏和碳酸盐矿物。同时,研究发现各区段石膏(硫酸盐矿物)平均含量自西向东明显下降,含镁矿物平均含量自西南向东北明显下降。结合察尔汗盐湖区卤水化学组成和水化学类型的分带,基本符合盐湖北部和东北部卤水富Ca~(2+),贫Mg~(2+)和SO_4~(2-)的沉积事实,进一步说明盐湖北部和东北部卤水和盐类沉积受具有氯化物型盐泉水的补给影响,为察尔汗盐湖混合掺杂成因提供了一定的矿物学证据。 相似文献
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柴达木盆地西部卤水水化学特征与找钾研究 总被引：19，自引：0，他引：19
柴达木盆地自中生代末-新生代初以来,四周山体不断抬升,形成"高山深盆"的沉积环境,为盆地带来了大量盐类物质,再加上晚第三纪干旱封闭的气候环境,使其西部沉积了广阔而厚层的盐岩.在对柴达木盆地西部第三系、第四系地层出露盐矿点实地考察的过程中,采集、分析了22件水样品的水化学组成,通过K+含量及一些水化学系数变化特征的研究,查明了卤水的水化学类型主要为氯化物型和硫酸镁亚型,其成因基本属溶滤岩盐卤水、深部循环水以及二者的混合水体,Br-、B3+、Sr2+、Li+等微量离子含量较高,区域差异性较大,出现显著水化学系数异常;相比之下,柴达木盆地西部南翼山坳陷Br-、B3、Sr2+、Li+含量值明显高于昆特依、察汗斯拉图、油砂山、开特米里克、油泉子、油墩子等坳陷区.Br×103/Cl、K×103/Cl等具找钾意义的水化学系数比其他地区高1～2倍,Br-、K+出现相对的富积,推测该坳陷成盐原始卤水曾浓缩达到较高析盐阶段或可能有大量深部富钾水体的补给,可作为寻找钾盐矿(富钾卤水)重点区域之一. 相似文献
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Katharine R. Hendry Michael P. Meredith Christopher I. Measures Damien S. Carson Rosalind E.M. Rickaby 《Estuarine, Coastal and Shelf Science》2010
The use of dissolved Al as a tracer for oceanic water masses and atmospheric dust deposition of biologically important elements, such as iron, requires the quantitative assessment of its sources and sinks in seawater. Here, we address the relative importance of oceanic versus atmospheric inputs of Al, and the relationship with nutrient cycling, in a region of high biological productivity in coastal Antarctica. We investigate the concentrations of dissolved Al in seawater, sea ice, meteoric water and sediments collected from northern Marguerite Bay, off the West Antarctic Peninsula, from 2005 to 2006. Dissolved Al concentrations at 15 m water depth varied between 2 and 27 nM, showing a peak between two phytoplankton blooms. We find that, in this coastal setting, upwelling and incorporation of waters from below the surface mixed layer are responsible for this peak in dissolved Al as well as renewal of nutrients. This means that changes in the intensity and frequency of upwelling events may result in changes in biological production and carbon uptake. The waters below the mixed layer are most likely enriched in Al as a result of sea ice formation, either causing the injection of Al-rich brines or the resuspension of sediments and entrainment of pore fluids by brine cascades. Glacial, snow and sea ice melt contribute secondarily to the supply of Al to surface waters. Total particulate Al ranges from 93 to 2057 mg/g, and increases with meteoric water input towards the end of the summer, indicating glacial runoff is an important source of particulate Al. The (Al/Si)opal of sediment core top material is considerably higher than water column opal collected by sediment traps, indicative of a diagenetic overprint and incorporation of Al at the sediment–water interface. Opal that remains buried in the sediment could represent a significant sink of Al from seawater. 相似文献
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Hydrochemical characteristics and controlling factors for waters’ chemical composition in the Tarim Basin,Western China 总被引：1，自引：0，他引：1
This paper covers the chemical and isotopic composition of river water, groundwater from wells (15–25 m), saline spring water and stagnant surface water providing evidence for controlling factors of water composition and water evolution process in the Tarim Basin, Xinjiang, western China. Analytical data for major and minor ions of totaling 537 water samples were obtained from both years of teamwork and old reference materials. It is found that the ion background value ratio SO4/Cl for river water (2.75) of the Tarim Basin is two times higher than that of the Qaidam Basin (0.88) and 18 times higher than seawater (0.14); K/Cl of these two basins (0.06 and 0.07) are all two times higher than seawater (0.02). This reveals that material sources of Lop Nur are relatively richer in potassium and sulfate, while poorer in chloride. Gradual changes of stable isotopic compositions in waters clearly indicate the effect of evaporation on water evolution of the basin. Besides evaporation and weathering of surrounding rocks, wide distribution of chloride type water, which commonly exist in saline springs/brines and seldom exist in other waters, indicates that hydrothermal Ca–Cl brines discharged from deep within the earth join water evolution of the basin. 相似文献
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Samira Adil Mohammed Bouabdellah Fidel Grandia Esteve Cardellach Àngel Canals 《Comptes Rendus Geoscience》2004,336(14):1265-1272
The Bou-Dahar PbZn Mississippi Valley deposits located in the eastern part of the High Atlas Range (Morocco) are hosted by a Liassic reefal complex. Fluid inclusion and ‘crush-leach’ data show that two distinct fluids were involved in the mineralisation deposition: a warmer, more saline fluid (180?°C, NaCl equivalent) and a cooler, less saline fluid (70?°C, 16 wt% equivalent NaCl). Mixing of these two fluids resulted in the precipitation of the ore. The solute composition of the ore-forming brine suggests that the MVT mineralising fluids were probably a mixture of halite-dissolution fluids and evaporated seawater. To cite this article: S. Adil et al., C. R. Geoscience 336 (2004). 相似文献
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D. CRAW 《Journal of Metamorphic Geology》1988,6(1):1-16
Abstract Fluids, some of which are CO2 -rich (up to 40 mol.% CO2 ) and some of which are highly saline (up to 18 wt% NaCl equivalent), are trapped as fluid inclusions in quartz-calcite (∼ metallic minerals) veins which cross-cut the pumpellyite-actinolite to amphibolite facies rocks of the Alpine Schist. Fluids were commonly trapped as immiscible liquid-vapour mixes in quartz and calcite showing open-space growth textures. Fluid entrapment occurred at fluid pressures near 500 bars (possibly as low as 150 bars) at temperatures ranging from 260 to 330° C. Saline fluids may have formed by partitioning of dissolved salts into an aqueous phase on segregation of immiscible fluids from a low-density CO2 -rich fluid. Calcite deposited by these fluids has δ13 C ranging from – 8.4 to – 11.5 and δ18 O from + 4 to + 13. Isotopic data, fluid compositions and mode of occurrence suggest that the fluids are derived from high-grade metamorphic rocks. Fluid interaction with wall-rock has caused biotite crystallization and/or recrystallization in some rocks and retrogression of biotite to chlorite in other rocks.
Fluid penetration through the rock is almost pervasive in many areas where permeability, probably related to Alpine Fault activity, has focussed fluids on a regional scale into fractured rocks. The fluid flow process is made possible by high uplift-rates (in excess of 10 mm/year) bringing hot rocks near to the surface. 相似文献
Fluid penetration through the rock is almost pervasive in many areas where permeability, probably related to Alpine Fault activity, has focussed fluids on a regional scale into fractured rocks. The fluid flow process is made possible by high uplift-rates (in excess of 10 mm/year) bringing hot rocks near to the surface. 相似文献
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沉积盆地卤水来源的非传统同位素示踪研究进展 总被引：1，自引：0，他引：1
世界上大多数的沉积盆地内,在结晶基底或者沉积地层内都有矿化度较高的卤水,由于这些卤水通常携带或富含有钾、硼、锂、溴、碘、铷、铯、稀有气体及重金属元素,因此,它们是地学界的研究热点之一。随着测试技术的不断进步,非传统同位素的应用也日益广泛,但在沉积盆地卤水来源和演化方面的研究还十分薄弱,对卤水的来源和演化也还存在争议。文章回顾了硼、锂、碘和惰性气体氦、氩同位素在卤水来源研究方面的进展,并指出由于单一同位素在解释上的片面性,多种同位素相结合的示踪方法研究沉积盆地卤水的来源是国际趋势。 相似文献