Metallogenic Dynamics of Zhashui Ag－Pb Polymetallic Ore Deposit in Shaanxi，China

ＭｅｔａｌｌｏｇｅｎｉｃＤｙｎａｍｉｃｓｏｆＺｈａｓｈｕｉＡｇ－ＰｂＰｏｌｙｍｅｔａｌｌｉｃＯｒｅＤｅｐｏｓｉｔｉｎＳｈａａｎｘｉ，ＣｈｉｎａＷｅｉＪｕｎｈａｏ；ＬｉＪｉａｎｗｅｉ；ＷａｎｇＳｉｙｕａｎ（ＦａｃｕｌｔｙｏｆＥａｒｔｈＲｅｓｏｕｒｃｅｓ...     

A Research on Fractal Dimension and Nonlinear Dynamic Model of Xintan Landslide，China

ＡＲｅｓｅａｒｃｈｏｎＦｒａｃｔａｌＤｉｍｅｎｓｉｏｎａｎｄＮｏｎｌｉｎｅａｒＤｙｎａｍｉｃＭｏｄｅｌｏｆＸｉｎｔａｎＬａｎｄｓｌｉｄｅ，ＣｈｉｎａＺｈｏｕＣｕｉｙｉｎｇ；ＴａｎｇＬｉａｎｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥａｒｔｈＳｃｉｅｎｃｅ，...     

Crustal Texture and Rheological Evolution of Tongbai－Dabie Orogenic Belt，China

Ｃｒｕｓｔａｌ　Ｔｅｘｔｕｒｅ　ａｎｄ　Ｒｈｅｏｌｏｇｉｃａｌ　Ｅｖｏｌｕｔｉｏｎ　ｏｆＴｏｎｇｂａｉ－Ｄａｂｉｅ　Ｏｒｏｇｅｎｉｃ　Ｂｅｌｔ，Ｃｈｉｎａ￥ＳｕｏＳｈｕｔｉａｎ（ＦａｃｕｌｔｙｏｆＥａｒｔｈＳｃｉｅｎｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓｉ...     

Depositional Environments of Bedded Chens in Western Yunnan Segment of Paleo－Tethys， China： a Geochemical Approach

ＤｅｐｏｓｉｔｉｏｎａｌＥｎｖｉｒｏｎｍｅｎｔｓｏｆＢｅｄｄｅｄＣｈｅｎｓｉｎＷｅｓｔｅｒｎＹｕｎｎａｎＳｅｇｍｅｎｔｏｆＰａｌｅｏ－Ｔｅｔｈｙｓ，Ｃｈｉｎａ：ａＧｅｏｃｈｅｍｉｃａｌＡｐｐｒｏａｃｈ￥ＨｅＦｕａｌａｎｇ；ＺｈｏｎｇＤａｉａｉ（Ｌａｂ...     

Geochemical Features of Ophiolite in Mianxian Lueyang Suture Zone，Qinling Orogenic Belt

ＧｅｏｃｈｅｍｉｃａｌＦｅａｔｕｒｅｓｏｆＯｐｈｉｏｌｉｔｅｉｎＭｉａｎｘｉａｎＬｕｅｙａｎｇＳｕｔｕｒｅＺｏｎｅ，ＱｉｎｌｉｎｇＯｒｏｇｅｎｉｃＢｅｌｔＬａｉＳｈａｏｃｏｎｇ；ＺｈａｎｇＧｕｏｗｅｉ（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｌｏｇｙ，Ｎｏｒｔ...     

Geometric and Dynamical Characteristics of Sequences in Yitong Graben

ＧｅｏｍｅｔｒｉｃａｎｄＤｙｎａｍｉｃａｌＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＳｅｑｕｅｎｃｅｓｉｎＹｉｔｏｎｇＧｒａｂｅｎ￥ＸｉｅＸｉｎｏｎｇ；ＳｕｎＹｏｎｇｃｈｕａｎ（ＤｅｐａｒｍｅｎｔｏｆＭｉｎｅｒａｌＲｅｓｏｕｒｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓ...     

METAMORPHOSED MICROCLASTIC ROCK-TYPE GOLD DEPOSITS IN CHINA

ＭＥＴＡＭＯＲＰＨＯＳＥＤＭＩＣＲＯＣＬＡＳＴＩＣＲＯＣＫＴＹＰＥＧＯＬＤＤＥＰＯＳＩＴＳＩＮＣＨＩＮＡＬｕＤｅｆｕＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００２９ＷａｎｇＸｉｕｚｈ...     

Stratigraphic Succession,Source-Rock Distribution and Paleoclimatic Zone in Meso-Cenozoic Basins,Eastern China

ＳｔｒａｔｉｇｒａｐｈｉｃＳｕｃｅｓｉｏｎ，Ｓｏｕｒｃｅ┐ＲｏｃｋＤｉｓｔｒｉｂｕｔｉｏｎａｎｄＰａｌｅｏｃｌｉｍａｔｉｃＺｏｎｅｉｎＭｅｓｏ－ＣｅｎｏｚｏｉｃＢａｓｉｎｓ，ＥａｓｔｅｒｎＣｈｉｎａ＊ＬｕＺｏｎｇｓｈｅｎｇＨｕａｎｇＱｉｓｈｅｎｇＦａ...     

Reservoir Diagenesis Sequence and Framework in Intracontinent Rift Basin,East China

ＲｅｓｅｒｖｏｉｒＤｉａｇｅｎｅｓｉｓＳｅｑｕｅｎｃｅａｎｄＦｒａｍｅｗｏｒｋｉｎＩｎｔｒａｃｏｎｔｉｎｅｎｔＲｉｆｔＢａｓｉｎ，ＥａｓｔＣｈｉｎａ＊ＬｉＺｈｏｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ...     

Calcareous Algae from Northeastern Brilon Reef Complex of Middle and Upper Devonian in Eastern Sauerland， Germany

ＣａｌｃａｒｅｏｕｓＡｌｇａｅｆｒｏｍＮｏｒｔｈｅａｓｔｅｒｎＢｒｉｌｏｎＲｅｅｆＣｏｍｐｌｅｘｏｆＭｉｄｄｌｅａｎｄＵｐｐｅｒＤｅｖｏｎｉａｎｉｎＥａｓｔｅｒｎＳａｕｅｒｌａｎｄ，Ｇｅｒｍａｎｙ￥ＨｏｎｇＴｉａｎｑｉｕ（ＤｅｐａｒｔｍｅｎｔｏｆＲｅ...     

川西南喜德热田地下水水文地球化学特征

地下热水的形成和化学组分特征常受断裂构造和热储地层岩性的影响。川西南喜德地热田内出露的冷泉水和地热水严格受断裂控制,前者为主断裂控制的浅循环型碎屑岩或岩溶裂隙孔隙水;后者则为次级断裂所控制的深循环型裂隙水,其热储层为碳酸盐岩。基于喜德热田形成的地质构造背景,通过开展热田内地热水和冷泉水水化学指标的测试和分析及水岩相互作用模拟,对该热田水文地球化学特征进行了研究。结果表明：喜德热田地热水和冷泉水水源均为大气降水,补给高程分别为2 874~3 092 m和2 584~2 818 m。受温度、含水层矿物类型、水岩相互作用的影响,地热水和冷泉水水化学类型和各组分差别较大,前者为HCO3·SO4-Ca·Mg型水,后者为HCO3-Ca·Mg型水。水岩相互作用模拟表明碳酸盐岩矿物、石膏矿物的溶解和沉淀及阳离子交换过程是导致地热水和冷泉水水化学组分差别较大的主要原因。此外,采用二氧化硅类温标计算喜德热田热储温度为56~90 ℃,循环深度为1 422~2 558 m。研究结果对阐明喜德热田的成因模式,地热水的进一步开发和热水资源的可持续利用具有重要意义。     

Neotectonic stage in the formation of the Khokhlovskoe uranium deposit, eastern Transural region: Structural, hydrochemical, mineralogical, and geochemical formation conditions

The structural, hydrochemical, mineralogical, and geochemical features of the Khokhlovskoe uranium deposit related to neotectonic processes are considered. The structural feature is expressed in neotectonic dislocations in the form of overall intense fragmentation of host rocks and widespread low-amplitude strike-slip faulting. The hydrochemical specificity is determined by the appearance of thermal carbonated formation water in ore-bearing aquifers. This water is similar in chemical and gas composition to hydrothermal solutions in fluid inclusions and mineral waters abundant in this district. The mineralogical and geochemical features comprise the occurrence of newly formed ferroan carbonates and late iron hydroxides in altered (bleached) pelitic rocks; the formation of silicic opal segregations in ore-bearing sand and sandstone; late sulfides, arsenides, and selenides of iron and other metals; and multiphase gel-pitchblende enriched in Zr especially typical of high-grade uranium ore. The age of high-grade ore determined by a precision uranium-ionium method coincides with the time when thermal carbonated water appeared in the host rocks. This time was estimated from a mathematical model of heat transfer and regional dynamics of underground water. This coincidence clearly indicates that the aforementioned processes are related to the late Quaternary neotectonic reactivation of the eastern Transural region.     

SOME LAWS GOVERNING THE MIGRATION OF COPPER,LEAD, AND ZINC IN WATER,AND THEIR SIGNIFICANCE IN PROSPECTING

The author attempts to explain some of the problems of hydrochemical prospecting by study of the migration of certain metals in water. In general the metal content of natural waters is lower than might be expected from their solubilities in pure water. In deposits of Kazakhstan there is a strong influence on the concentration of these elements by the chemical composition and pH of the water. Lead and copper contents are strongly dependent on pH (decreasing with greater pH) and zinc less so. The pH limit of indistinct and discontinuous hydrochemical anomalies is about 7 for copper, 7.2 for lead, and 7.5 for zinc. The predominantly alkaline or neutral waters of raremetal deposits precludes usage of copper, lead, and zinc as indicators. Careful studies are therefore necessary to adequately evaluate anomalies. Data from diverse, unmineralized rocks indicates that limestones and carbon-enriched bottom deposits, and acid intrusives and their tuffs, are most active in lead sorption. The structure of rocks and microorganisms influence metal content in associated waters.—J. A. Redden.     

Permeabilities and Chemical Properties of Water in Crystalline Rocks of the Black Forest, Germany

Investigations were carried out to determine the hydraulic and hydrochemical properties of crystalline rocks in the Black Forest of Germany and neighbouring regions. Rock permeabilities (K) were determined to a depth of 3500 m. These parameters range from K = 3.5 × 10-10 ms-1 to K = 8.7 × 10-5 ms-1; and can increase up to an order of magnitude which is typical for porous aquifers. It is shown that on an average, granites are more pervious than gneisses and only the permeabilities of gneisses decrease with depth. The geochemistry of natural waters in crystalline rocks is not constant, but varies with depth and location. The concentration increases with depth and the water-type changes from a Ca–-Na–-HCO 3-type (or Na–-Ca–-HCO3–-) at shallow depths to a Na–-Cl-type at greater depths. Thermal springs are found only in granitic rocks with on average higher permeabilities than in gneisses. Thermal waters are welling up in valleys at the bottom of steep mountains. The chemical composition of thermal spring water is identical to that of water found at greater depths. Using geothermometers it is found, that the depth of the deposits of thermal spring water in the crystalline basement rocks of the Black Forest is some 1000 m below the surface. The topographic relief in the mountains induces a deep circulation of infiltrating rain-water with an upwelling as thermal springs in the valleys.     

Origin of salinity of deep groundwater in crystalline rocks

Deep groundwater in fractured crystalline basement has been reported from deep mines and from scientific deep wells. Highly saline brines have been described from several km depth in the continental basement of the Canadian, Fennoscandian and Ukrainian shields and elsewhere in the world. The origin of salinity is unknown and many different possibilities have been presented. We compare the compositional evolution of deep waters in the Black Forest basement, SW Germany, with those of other deep crystalline waters, and use halogen systematics (e.g. Cl/Br ratios) and other parameters of the waters to deduce the origin of their salinity. In the Black Forest the composition of deep thermal waters results from chemical interaction of surface water with the rock matrix (mainly weathering of plagioclase and mica) and from mixing of the reacted water with stagnant saline deep water. Here we show by Na/TDS-and Cl/TDS-investigations, by molality-ratios of the Na and Cl concentrations, and by Cl/Br systematics that these deep saline waters have a marine origin. The Cl/Br ratios in deep crystalline waters are very close to normal marine ratios (Cl/Br = 288 ppm basis). In contrast, Cl/Br ratios of other possible sources of salinity show distinctly different Cl/Br ratios: water derived from dissolved Tertiary halite deposits of the rift valley is in the order of Cl/Br = 2400 and water from dissolved Muschelkalk halite deposits has values of about Cl/Br = 9900. Leaching experiments on crystalline rocks, on the other hand, show that the average Cl/Br ratio of crystalline rocks is far below Cl/Br = 100.     

Hydrochemistry of geothermal water in Tianshui and adjacent area, Gansu province, China

A geochemical study on thermal water has been carried out in Tianshui and its adjacent area, Gansu province, China. Chemical and isotopic contents were employed in the investigation on the origin and evolution of thermal water and the evaluation of reservoir temperature in the geothermal systems. Thermal waters in Wushan and Tianshui are characterized by outlet temperatures from 15 to 38°C and low TDS (226?C255?mg/L), defined as bicarbonate water. Its origin may be attributed to the interaction between meteoric rain, biotite plagioclase gneiss and carbonate reservoir rocks. In contrast, thermal waters in Tongwei and Qingshui have higher outlet temperatures of 25?C54.2°C and a moderate TDS of 915?C1,793?mg/L, regarded as sulfate waters. These sulfate waters may arise from the interaction between meteoric water, granite and amphogneiss. Isotopic data presented here suggest that thermal waters in the study area have a meteoric origin without being significantly effected by water?Crock isotope exchange. Chemical geothermometry indicates the existence of a deep geothermal reservoir of low-to-medium enthalpy (70?C111°C) in the Tianshui study area.     

西藏搭格架地热区天然水的水化学组成与稳定碳同位素特征

为探究青藏高原搭格架地热区地热水、湖水、河水、冰雪融水等天然水体的水化学组成及物质来源控制因子,于2014年8月对该地区进行了考察和取样。利用紫外-可见光分光光度计和ICP-OES测定了水样中各阴、阳离子含量,利用Gas Bench连接同位素质谱仪测定了水样中溶解无机碳（DIC）同位素比值。结果表明,地热水中总溶解固体（TDS）含量为977.13~1 279.50 mg/L,阳离子以K+和Na+为主,阴离子以HCO3-和Cl-为主,湖水的TDS含量为77.81~810.94 mg/L,阳离子以Na+和Ca2+为主,阴离子以HCO3-(CO32-)和SO42-为主,地热水和湖水的水化学类型为HCO3-Na型;河水和冰雪融水的各离子含量较低,水化学类型为HCO3-Ca型;地热水的DIC浓度范围为9.2~15.4 mmol/L,δ13CDIC值为-9.09‰~-0.95‰;湖水的DIC浓度为1.1~9.7 mmol/L,δ13CDIC值为-8.84‰~-0.27‰。根据水化学Gibbs分布模式图判断出区域水化学特征主要受硅酸盐岩风化控制,以钠长石和钾长石风化为主,但是地热水的水化学组分受到硅酸盐岩和蒸发盐岩共同控制。通过碳同位素比值分析对区域主要风化过程中CO2的来源示踪表明,湖区周围的硅酸盐风化其碳源主要为土壤CO2,热泉区硅酸盐水解其碳源为地球深部CO2输入。      

琼东南盆地深水区烃源岩沉积模式及差异热演化

琼东南盆地深水区是目前的天然气勘探热点,但其烃源岩沉积模式和演化特征认识的不足制约了勘探成效.为识别和评价琼东南盆地深水区烃源岩,综合应用地震沉积学、有机地球化学及构造地质学分析方法,对比剖析渐新统含煤三角洲~浅海相泥岩的生烃母质、沉积背景及与已发现油气的对应关系.研究表明,渐新统三角洲的发育规模及古地貌控制了海陆过渡相煤系和海相陆源型烃源岩的分布,断-拗转换期凹凸相间的半封闭浅海环境有利于形成生气为主、油气兼生的渐新统海相陆源型烃源岩;深水区海相陆源型烃源岩分布、热演化及生排烃过程控制了天然气资源潜力,据此对生气凹陷进行分类评价并提出乐东、陵水及松南等Ⅰ类富生气凹陷.      

A geochemical study of the impact of irrigation and aquifer lithology on groundwater in the Upper Yakima River Basin,Washington, USA

The Yakima River, a major tributary of the Columbia River, is currently overallocated in its surface water usage in part because of large agricultural water use. As a result, groundwater availability and surface water/groundwater interactions have become an important issue in this area. In several sub-basins, the Yakima River water is diverted and applied liberally to fields in the summer creating artificial recharge of shallow groundwater. Major ion, trace element, and stable isotope geochemistry of samples from 26 groundwater wells from a transect across the Yakima River and 24 surface waters in the Kittitas sub-basin were used to delineate waters with similar geochemical signatures and to identify surface water influence on groundwater. Major ion chemistry and stable isotope signatures combined with principal component analysis revealed four major hydrochemical groups. One of these groups, collected from shallow wells within the sedimentary basin fill, displays temporal variations in NO₃ and SO₄ along with high δ¹⁸O and δD values, indicating significant contribution from Yakima River and/or irrigation water. Two other major hydrochemical groups reflect interaction with the main aquifer lithologies in the basin: the Columbia River basalts (high-Na groundwaters), and the volcaniclastic rocks of the Ellensburg Formation (Ca–Mg–HCO₃ type waters). The fourth major group has interacted with the volcaniclastic rocks and is influenced to a lesser degree by surface waters. The geochemical groupings constrain a conceptual model for groundwater flow that includes movement of water between underlying Columbia River basalt and deeper sedimentary basin fill and seasonal input of irrigation water.     

Hydrogeology and hydrogeochemistry of Günyüzü semi-arid basin (Eski?ehir, Central Anatolia)

Groundwater is often the only water source in semi-arid regions of Turkey. Günyüzü Basin, located in the Sakarya River basin, SW of Eskişehir, exhibits semi-arid conditions. The study area is composed of Paleozoic metamorphic rocks, Eocene granitic rocks, Neogene sedimentary rocks, and Quaternary alluvium. In the basin, Paleozoic Marbles are the main reservoir rocks for hot and cold water, bordered by impermeable diabases dykes at the sides and by impermeable granites and schists. Neogene-aged limestones, conglomerates and alluvium represent the other significant aquifers. Water samples chosen to exemplify the aquifer characteristics, were collected from springs and wells in both the dry and the wet seasons. The cation and anion permutation of the samples show that carbonates are the dominant lithology in the formation of chemical composition. δ¹⁸O (−11.2 to −8.9‰) and δ²H (−79 to −60‰) isotopic values show that all waters (thermal and cold) are meteoric in origin. The hydrological, hydrochemical, and isotopic properties of the waters reveal that there exist two main groups of groundwater systems; one of these is deep circulating, while the other one is shallow. Tritium values, 0–4 TU (Tritium Unit) indicate the presence of old, static water in these aquifer systems.