流体包裹体成分测定的低温相变和显微拉曼光谱分析技术研究进展   总被引：2，自引：1，他引：1  

葛云锦  陈勇  周瑶琪 《岩矿测试》2008,27(3):207-210

论述了包裹体低温分析技术的原理以及进展。传统的流体包裹体低温分析技术是以显微冷冻测温测定无机盐体系为主,目前已发展到应用低温原位拉曼光谱技术对包裹体中的阳离子和阴离子进行定量-半定量分析。油气包裹体原位低温分析技术也取得了较大的突破,对不同成分油气包裹体低温下的相变过程取得了一定的认识,据此对油气包裹体进行分类,推测其主要成分,为油气包裹体计算提供基础参数。  相似文献   

新疆阿尔泰蒙库铁矿床的成矿流体及成矿作用   总被引：30，自引：8，他引：22  

杨富全  毛景文  柴凤梅  刘锋  周刚  耿新霞  刘国仁  徐林刚 《矿床地质》2008,27(6):659-680

蒙库大型铁矿床赋存于上志留统—下泥盆统康布铁堡组变质火山-沉积岩系中,容矿岩石为石榴子石矽卡岩、变粒岩、浅粒岩和大理岩。矿体总体顺层分布,空间上与矽卡岩密切相关。研究表明,矽卡岩期石榴子石以发育玻璃质熔融包裹体、流体熔融包裹体和流体包裹体为特征,晚期矽卡岩阶段矿物中发育液相包裹体,变质期矿物中主要发育液相包裹体和含子矿物包裹体。矽卡岩期熔融包裹体的均一温度为1100℃,早期矽卡岩阶段流体包裹体均一温度变化于193～499℃,在450℃、350℃和230℃出现峰值。中期矽卡岩阶段均一温度变化于236～550℃,峰值为350℃。区域变质期均一温度介于132～513℃,在350℃、230℃和190℃出现峰值。流体包裹体的盐度w(NaCleq)介于1.23%～60.31%,流体密度变化于0.60～1.16g/cm3。石榴子石、石英和方解石的δ18OSMOW变化于0.2‰～8.4‰,δ18OH2O介于-5.1‰～5.33‰,δD为-127‰～-81‰,表明矽卡岩期成矿流体主要是岩浆水,混合少量大气降水;变质期流体主要为大气降水,为混合变质水。方解石δ13CPDB变化于-6.1‰～-2.3‰,表明流体中碳来自深部或地幔。成矿时代为早泥盆世早期(略晚于404～400Ma),成矿作用与矽卡岩的退化变质作用有关。  相似文献   

云南官房铜矿床矿石矿物特征及银的赋存状态   总被引：1，自引：0，他引：1  

刘德利  刘继顺  张彩华  韩海涛  周余国 《矿床地质》2008,27(6):695-704

通过显微镜鉴定、电子探针(EPMA)及扫描电镜能谱分析(SEM/EDS)等方法,首次对官房铜矿的矿物组合和银的赋存状态进行了研究。初步查明,矿石矿物为中-低温热液成因,并受火山机构及断裂构造的控制;银矿物主要为碲银矿和辉银矿。矿石中银与铜呈明显正相关关系,而方铅矿中不含银。银主要以类质同象的形式赋存于含铜矿物或黄铁矿中;银的独立矿物含量低,且多呈包裹体的形式存在于黄铜矿、斑铜矿及黄铁矿中,或以微细粒状赋存于矿物颗粒间和斑铜矿的表面。  相似文献   

豫西前河构造蚀变岩型金矿成矿过程中的流体-岩石反应     

曹烨  李胜荣  申俊峰  要梅娟  李庆康  毛付龙 《矿床地质》2008,27(6):714-726

前河金矿区位于华北地台南缘,赋存在中元古界熊耳群安山岩和英安岩中,矿体受断裂破碎带控制。含矿热液在迁移过程中与围岩发生了广泛的流体-岩石反应而引起热液蚀变。本区石英中有4种类型的流体包裹体,均一温度范围为145～331℃,其中含CO2包裹体的完全均一温度主要分布在中-高温区。成矿流体的密度和压力变化范围分别是0.68～0.94g/cm3和(367.01～896.55)×105Pa。金大量沉淀成矿时的流体特征为:温度213～260℃、密度0.80～0.89g/cm3和压力(502.86～710.57)×105Pa。流体相为SO42->Na >Cl->K 型,CO2/H2O比值及N2、H2S、Ar、C2H6等挥发分的含量明显增高,f(CO2)、f(H2S)、f(CH4)和Eh值增大;f(O2)、f(H2O)和pH值减小。在青磐岩化安山岩的基础上发生的流体-岩石反应是造成本矿床金沉淀成矿的最主要原因。  相似文献   

塔里木盆地塔中1井藻纹层白云岩与竹叶状白云岩成因——基于岩石学、元素与同位素地球化学的厘定   总被引：1，自引：0，他引：1  

陈永权  周新源  赵葵东  杨文静  董晨阳  朱长见 《地质学报》2008,82(6):826-834

塔里木盆地寒武系—奥陶系底部发育了大量的白云岩, 白云岩中赋存丰富的油气资源, 但是由于塔里木盆地白云岩研究基础薄弱,限制了塔里木盆地白云岩型油气藏的勘探。本文选择塔中地区塔中1井下奥陶统藻纹层白云岩与夹层竹叶状白云岩作为对象,应用岩石学与地球化学方法对其成因问题进行了研究。藻纹层白云岩与夹层竹叶状白云岩的宏观构造与微观结构指示其可能形成于高能的潮坪环境;低有序度值（0.6）与塔北地区中寒武统阿瓦塔格组潮坪同沉积白云岩(有序度值0.61)特点一致,指示该白云岩结晶速率较快;同时,高Fe、Mn含量与低U、Mo含量也与氧化环境的潮坪相一致。藻纹层白云岩与夹层竹叶状白云岩δ18O值非常集中, 变化在-7.4‰～-5.8‰;87Sr/86Sr组成变化很小,在0.709015～0.709276之间,与前人报道的晚寒武世－早奥陶世海水同位素特征一致,同时白云岩的稀土元素配分模式也与下奥陶统泥晶灰岩一致,指示了白云岩的沉积/成岩物质来源于蒸发海水;白云岩δ13C值变化从-2.5‰～+1.6‰,并有着随深度增加而升高的变化规律,可能指示了古海洋的碳同位素氧化。藻纹层白云岩与夹层竹叶状白云岩的构造特点具有原生沉积特征,同时白云岩CaO与MgO含量的正相关关系也支持该白云岩原生沉积特点。因此,塔里木盆地塔中1井钻遇的下奥陶统藻纹层白云岩与夹层竹叶状白云岩为潮坪环境下,从蒸发海水中快速沉积形成的。  相似文献   

Plant distribution at the mobile dune scale and its relevance to soil properties and topographic features     

Xiaoan Zuo  Halin Zhao  Xueyong Zhao  Yirui Guo  Yulin Li  Yayong Luo 《Environmental Geology》2008,54(5):1111-1120

A survey was conducted in an 11-year recovery mobile dune (RMD11) and a 20-year recovery mobile dune (RMD20), in Horqin Sandy Land, Northern China, to determine plant distribution at the mobile dune scale and its relevance to soil properties and topographic features. The results showed that (1) vegetation cover and species number increased from dune top to bottom in the restoration process of mobile dune; (2) the average value of soil organic C, total N, pH, relative height of sampling site, very fine sand content and soil water contents (40−60 and 60−80 cm) of RMD11 were less than that of RMD20, respectively, and there were significant differences (P < 0.05) between the two dunes; (3) soil resources were redistributed by shrub restoration and relative height of sampling site on dune. The distribution of sand pioneer plant, Agriophyllum squarrosum, was positively related to the relative height of sampling site and soil water content, while that of other herbaceous plants was positively related to soil nutrients in the restoration process of mobile dune. These results suggest that at mobile dune scale, plant distributions are determined by a combination of soil properties and topographic feature. Much effort should be made to preserve the interdune lowland and to improve the level of soil nutrients on mobile dune.  相似文献   

Occurrence and evolution of the Xiaotangshan hot spring in Beijing, China   总被引：1，自引：0，他引：1  

Zhou Haiyan  Zhou Xun  Chai Rui  Yu Lan  Liu Chunhui  Li Liangping 《Environmental Geology》2008,53(7):1483-1489

Thermal groundwater occurs in bedrock aquifers consisting of the dolomite of the Wumishan Group of the Jixianin System and the Cambrian carbonate in the Xiaotangshan geothermal field near the northern margin of the North China Plain, China. The hot water in the geothermal field of basin-type discharges partly in the form of the Xiaotangshan hot spring under natural conditions. The hot water has TDS of less than 600 mg/L and is of Na·Ca-HCO₃ type. The geothermal water receives recharge from precipitation in the mountain area with elevation of about 500 m above sea level to the north of the spring. Thermal groundwater flows slowly south and southeast through a deep circulation with a residence time of 224 years estimated with the Ra–Rn method. The Xiaotangshan hot spring dried up in the middle of the 1980s owing to the increasing withdrawal of the hot water in the geothermal field in the past decades. The water level of the geothermal system still falls continually at an annual average rate of about 2 m, although water temperature changes very little, indicating that the recharge of such a geothermal system of basin-type is limited. Over-exploitation has a dramatic impact on the geothermal system, and reduction in exploitation and reinjection are required for the sustainable usage of the hot water.  相似文献   

Response of groundwater chemistry to water deliveries in the lower reaches of Tarim River,Northwest China   总被引：2，自引：0，他引：2  

Yongjin Chen  Kefa Zhou  Yaning Chen  Weihong Li  Jiazhen Liu  Tao Wang 《Environmental Geology》2008,53(6):1365-1373

In this paper, we analysed the monitored data from nine groundwater-monitoring transects in the lower reaches of Tarim River during the five times of stream water deliveries to the river transect where the stream flow ceased. The results showed that the groundwater depth in the lower reaches of Tarim River rose from −9.30 m before the conveyances to −8.17 and −6.50 m after the first and second conveyances, −5.81 and −6.00 m after the third and fourth the conveyance, and −4.73 m after the fifth. The horizontal extent of groundwater recharge was gradually enlarged along both sides of the channel of conveyance, i.e., from 250 m in width after the first conveyance to 1,050 m away from the channel after the fourth delivery. With the rising groundwater level, the concentrations of major anions Cl⁻, SO₄²⁻ and cations Ca²⁺, Mg²⁺, Na⁺, as well as total dissolved solids (TDS) in groundwater underwent a significant change. The spatial variations in groundwater chemistry indicated that the groundwater chemistry at the transect near Daxihaizi Reservoir changed earlier than that farther from it. In the same transect, the chemical variations were earlier in the monitoring well close to watercourse than that farther away from the stream. In general, the concentration of the major ions and TDS at each monitoring well increased remarkably when the water delivery started, and decreased with the continued water delivery, and then increased once again at the end of the study period. Hence, the whole study period may be divided into three stages: the initial stage, the intermediate stage and the later stage. According to the three stages of groundwater chemistry reaction to water delivery and the relationships between groundwater chemical properties and groundwater depths, we educe that under the situation of water delivery, the optimum groundwater depth in the lower reaches of the Tarim River should be −5 m.  相似文献   

Distribution of Cd,Pb, Zn and Cu and their chemical speciations in soils from a peri-smelter area in northeast China   总被引：2，自引：0，他引：2  

Ping Du  Nandong Xue  Li Liu  Fasheng Li 《Environmental Geology》2008,55(1):205-213

An exploratory study on soil contamination of heavy metals was carried out surrounding Huludao zinc smelter in Liaoning province, China. The distribution of total heavy metals and their chemical speciations were investigated. The correlations between heavy metal speciations and soil pH values in corresponding sites were also analyzed. In general, Cd, Zn, Pb, Cu and As presented a significant contamination in the area near the smelter, comparied with Environmental Quality Standards for Soils in China. The geoaccumulation index showed the degree of contamination: Cd > Zn > Pb > Cu > As. There was no obvious pollution of Cr and Ni in the studied area. The speciation analysis showed that the dominant fraction of Cd and Zn was the acid soluble fraction, and the second was the residual fraction. Pb was mostly associated with the residual fraction, which constituted more than 50% of total concentration in all samples. Cu in residual fraction accounted for a high percentage (40–80%) of total concentration, and the proportion of Cu in the oxidizable fraction is higher than that of other metals. The distribution pattern of Pb and Zn was obviously affected by soil pH. It seemed that Pb and Zn content in acid solution fraction increased with increasing soil pH values, while Cd content in acid soluble fraction accounted for more proportion in neutral and alkaline groups than acidic one. The fraction distribution patterns of Cu in three pH groups were very similar and independent of soil pH values. And the residual fraction of Cu took a predominant part (50%) of the total content.  相似文献   

Recharge source and hydrogeochemical evolution of shallow groundwater in a complex alluvial fan system,southwest of North China Plain   总被引：4，自引：0，他引：4  

Fadong Li  Guoying Pan  Changyuan Tang  Qiuying Zhang  Jingjie Yu 《Environmental Geology》2008,55(5):1109-1122

Many cities around the world are developed at alluvial fans. With economic and industrial development and increase in population, quality and quantity of groundwater are often damaged by over-exploitation in these areas. In order to realistically assess these groundwater resources and their sustainability, it is vital to understand the recharge sources and hydrogeochemical evolution of groundwater in alluvial fans. In March 2006, groundwater and surface water were sampled for major element analysis and stable isotope (oxygen-18 and deuterium) compositions in Xinxiang, which is located at a complex alluvial fan system composed of a mountainous area, Taihang Mt. alluvial fan and Yellow River alluvial fan. In the Taihang mountainous area, the groundwater was recharged by precipitation and was characterized by Ca–HCO₃ type water with depleted δ¹⁸O and δD (mean value of −8.8‰ δ¹⁸O). Along the flow path from the mountainous area to Taihang Mt. alluvial fan, the groundwater became geochemically complex (Ca–Na–Mg–HCO₃–Cl–SO₄ type), and heavier δ¹⁸O and δD were observed (around −8‰ δ¹⁸O). Before the surface water with mean δ¹⁸O of −8.7‰ recharged to groundwater, it underwent isotopic enrichment in Taihang Mt. alluvial fan. Chemical mixture and ion exchange are expected to be responsible for the chemical evolution of groundwater in Yellow River alluvial fan. Transferred water from the Yellow River is the main source of the groundwater in the Yellow River alluvial fan in the south of the study area, and stable isotopic compositions of the groundwater (mean value of −8.8‰ δ¹⁸O) were similar to those of transferred water (−8.9‰), increasing from the southern boundary of the study area to the distal end of the fan. The groundwater underwent chemical evolution from Ca–HCO₃, Na–HCO₃, to Na–SO₄. A conceptual model, integrating stiff diagrams, is used to describe the spatial variation of recharge sources, chemical evolution, and groundwater flow paths in the complex alluvial fan aquifer system.  相似文献