花岗岩地区碳汇计算及影响因素研究

基于对泉水水化学特征(pH、t、Ca2 、Mg2 、K 、Na 、HCO3-、HCO3-、SO2-4)的观测,探讨了云南维西孔隙水、浅部裂隙水、深部构造裂隙水、花岗岩与灰岩接触带水、花岗岩与第四系堆积物接触带水风化碳汇规律及影响因素.并在全国花岗岩分区的基础上,选取云南维西、广西新寨、湖南郴州和北京怀柔为代表点进行区域对比,并初步计算了全国花岗岩碳汇量.     

潍坊南部山区地下水赋存规律及地电特征研究

通过对潍坊南部山区水文地质条件进行详细研究,根据研究区地下水赋存特征,将地下水类型划分为第四系孔隙水、碳酸盐岩类裂隙岩溶水和基岩裂隙水三类。根据研究区地貌类型,孔隙水划分为山前坡洪积扇和近山前冲洪积平原两种类型;根据研究区岩溶发育类型,岩溶水划分为岩性接触溶蚀带型、层状岩溶裂隙带型及岩溶溶蚀破碎带型;根据研究区含水裂隙成因,裂隙水划分为风化裂隙水、构造裂隙水和成岩裂隙水三类。本文对研究区内各类地下水的赋存规律进行研究,初步总结了各类地下水的地电特征,为区内地下水资源的合理开发利用提供科学依据。     

甘肃阳山特大型金矿床水文地质条件和环境地质问题研究

阳山金矿床为一尚未开发的特大型金矿床。矿区地下水类型有第四系孔隙水、基岩裂隙水和构造带脉状裂隙水等三类。第四系松散堆积物及地表浅部节理裂隙发育的基岩为区内含水层,深部节理裂隙不发育的千枚岩、灰岩及斜长花岗斑岩为矿区隔水层。矿区西侧马连河水水质较好,可作为矿山开发用水源地。矿山开采过程中,第四系松散覆盖层的厚度、地下水对矿区有害元素的溶解程度以及地表水、地下水的二次污染等,均为矿山开发时应该研究的水文地质和环境地质问题。     

白布井田充水因素分析

通过对白布井田水文地质资料的分析研究,认为浅部6上、6中、7号煤层开采时充水水源为顶板进水的长兴组岩溶裂隙水、含煤地层裂隙水、滑坡体中的孔隙水;充水通道主要为裂隙、岩溶管道、导水裂隙带、断层带。井田深部低于白布河水位的各煤层除受上述充水水源影响外,也受河水的影响。开采东北、东南角深部28、33号煤层时,局部还会受下部茅口组岩溶水充水水源的影响。井田属以裂隙、孔隙含水层充水为主,水文地质条件中等的煤矿床。     

火山岩储层斜长石选择性溶蚀的岩石学特征和热力学条件

长石溶孔是火山岩中重要的孔隙类型之一,火山岩的主要孔隙类型中长石溶孔所占的比例在1.24%～60.61%之间,在储层中占有重要地位.从岩相学、岩石化学CIPW标准矿物成分、热力学等方面论证了斜长石的选择性溶蚀.岩相学特征表现出斜长石选择性溶蚀的特征,即钙长石溶蚀时钠长石没有溶蚀,同时出现斜长石选择性溶蚀时钠长石和钾长石生长的现象.斜长石选择性溶蚀得到了CIPW标准矿物成分的支持,在CIPW标准矿物成分中长石的端元组分主要为钠长石和钾长石,而钙长石绝大多数为0或接近0.热力学研究表明,在同样的温度、压力和地层水成分的条件下,在斜长石中优先溶解钙长石组分.当地层水中Na+和K+浓度达到饱和时发生钠长石和钾长石沉淀,出现斜长石选择性溶蚀的同时发生钠长石和钾长石生长的现象.     

火山岩储层斜长石选择性溶蚀的岩石学及热力学研究

长石溶孔是火山岩中重要的孔隙类型之一,火山岩的主要孔隙类型中长石溶孔所占的比例在1.24%～60.61％之间,在储层中占有重要地位。从岩相学、岩石化学CIPW标准矿物成分、热力学等方面论证了斜长石的选择性溶蚀。岩相学特征表现出斜长石选择性溶蚀的特征,即钙长石溶蚀时钠长石没有溶蚀,同时出现斜长石选择性溶蚀时钠长石和钾长石生长的现象。斜长石选择性溶蚀得到了CIPW标准矿物成分的支持,在CIPW标准矿物成分中长石的端元组分主要为钠长石和钾长石,而钙长石绝大多数为0或接近0。热力学研究表明,在同样的温度、压力和地层水成分的条件下,在斜长石中优先溶解钙长石组分。当地层水中Na+和K+浓度达到饱和时发生钠长石和钾长石沉淀,出现斜长石选择性溶蚀的同时发生钠长石和钾长石生长的现象。     

长白山区地下水重金属及砷的化学形态研究方法及其分布特征

该区地处第二松花江流域上游,地质构造复杂,岩浆活动频繁,水文地球化学环境属湿润,寒冷的中低山地下水强溶滤迁移区。根据水文地质特征,分别在花岗岩网状风化裂隙水、玄武岩孔洞裂隙水、松散岩类孔隙潜水中布设了54个采样点并采集了样品,研究了地下水中重金属(Cu、Pb、Zn、Cr、Ni、Cd、Hg)和砷的化学形态。其目的是为深入开展地下水环境的元素化学形态研究方法方面的探讨。     

长石溶解过程的热力学计算及其在碎屑岩储层研究中的意义

基于对反应过程吉布斯自由能增量的计算,探讨了长石的3种端元组成（钾长石、钠长石和钙长石）溶解生成高岭石、伊利石的热力学性质。结果表明：钾长石、钠长石和钙长石在成岩过程中均可以自发地向高岭石、伊利石转化。在长石的这3种类型中,钙长石溶解反应的吉布斯自由能增量最低,并明显具有正的温度效应,说明钙长石最不稳定且在低温条件下更易溶解;钾长石溶解反应的吉布斯自由能增量最高,并具有较大的负的温度效应,说明钾长石稳定性较高且在埋藏成岩条件下更易溶解;钠长石溶解反应的吉布斯自由能增量中等,受温度影响不大,但温度升高时其稳定性仍有所下降。与温度相比,压力对反应的吉布斯自由能增量几乎没有影响。因此,砂岩中的次生孔隙,尤其是埋藏成岩过程中形成的次生孔隙应与钾长石的关系最为密切,其次是钠长石,但其可能受到蒙皂石向伊利石转化反应的缓冲,在埋藏成岩条件下溶解较为困难,并可能造成斜长石的钠长石化或自生钠长石的沉淀。     

平凉南部山区岩溶裂隙水分析

运用构造控水、水化学同位素、地下水动态等方法,对平凉南部岩溶裂隙水进行了深入的分析与讨论。该区储水空间以岩溶裂隙为主,岩溶水的空间分布明显断裂构造控制。裸露岩溶地下水以大气降水起源为主,浅埋型岩溶水多表现为混合水的特征。地下水动态呈现气候型,水岩相互作用形式溶滤-混合型,呈低矿化淡水。根据以上特征,划分了3个相对独立的岩溶水系统。     

吉林省氟中毒病区水文质地特征及防氟改水对策

本文根据饮水中氟的来源,将全省氟中毒划分为深循环热水型、火山活动—地下水富集型、地下水运移富集型和淋溶富集型4种类型。1、深循环热水型:水中氟来源于花岗岩浆的释放,可采用白垩系裂隙孔隙水和玄武岩孔洞裂隙水改水防氟。2、火山活动—地下水富集型:氟来源于古近系、新近系火山活动期间岩浆中氟的释放,可用白垩系泉水村组孔隙裂隙水改水防氟。3、地下水运移富集型:地下水氟来源于大兴安岭,东部高平原和松辽分水岭岩石中氟的风化、淋溶,并在运移至松嫩平原的地下水区域径流—汇水区和汇水区富集形成高氟水,可用新近系泰康、大安组裂隙孔隙水;白垩系明水、四方台和嫩江组孔隙裂隙水改水防氟。4、淋溶富集型:地下水中氟来源于黄土状亚粘土和亚粘土中的氟的溶出,可用白垩系青山口组孔隙裂隙水改水防氟。     

广汉市平原区浅层地下水化学演化及其控制因素

为在广汉市城乡规划过程中提供地下水资源开发利用的基础信息,采用矿物风化系统分析、相关性分析、主成分分析和PhreeQC反向水文地球化学模拟等方法对广汉市平原区的浅层地下水的地下水水化学组分进行分析,确定了浅层地下水的水化学演化及控制因素,完成了地下水资源的质量及时空分布特征分析。分析表明：Gibbs图显示岩石风化主导该区地下水水化学特征,风化过程产生离子和次生矿物又经历水解作用,在矿物风化系统稳定场图中显示水样中铝硅酸盐矿物逐渐趋于溶解,碳酸盐矿物处于饱和状态;PhreeQC反向水文地球化学模拟结果显示在水流模拟路径上主要发生了钙蒙脱石、钾长石溶解和高岭石、石英、钠长石的沉淀,以及Ca-Na₂之间的阳离子交换吸附作用;离子相关性和主成分分析进一步的验证了溶滤作用、蒸发浓缩作用和阳离子交换吸附作用是引起浅层地下水水化学过程和矿物组成改变的主要原因。研究区地下水水质总体不会对人体健康造成不良影响。     

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。     

滦河流域中上游富锶地下水成因类型与形成机制

承德市滦河流域富锶矿泉水资源丰富,成因类型多样,具有典型研究意义。通过水化学图解与多元统计分析、离子比值分析、矿物平衡体系分析,分析富锶地下水形成的地球化学背景,分区阐述富锶地下水水化学特征,探讨富锶地下水的形成机制。结果表明,研究区水化学类型以HCO3-Ca·Mg、HCO3·SO4-Ca、HCO3-Ca、HCO3·SO4-Ca·Mg为主。富锶地下水的形成受地质构造格局和岩浆活动控制,地质建造锶元素丰度影响,水文地球化学条件制约。断裂构造和地层岩性控制着富锶地下水形成分布的总体特征,水文地质条件影响着地下水化学锶元素的地球化学响应机制。地下水锶富集来源为含水介质长石矿物、碳酸盐矿物的风化溶解和阳离子交换吸附作用,矿泉水出露机制分为构造断裂深循环淋溶型、裂隙浅循环淋溶型、补给富集埋藏型3种类型。坝上高原孔隙裂隙水系统富锶地下水形成作用主要受大气降水和溶滤作用控制,滦河中上游裂隙水系统地下水阳离子交换吸附作用强烈,滦河中游孔隙岩溶裂隙水系统地下水化学主要受溶滤作用控制,蒸发浓缩作用和人为活动影响。     

Deep groundwater in the crystalline basement of the Black Forest region

Two major types of groundwater can be readily distinguished in the Variscian crystalline basement of the Black Forest in S–W Germany. Saline thermal water utilized in spas has its origin in 3–4 km deep reservoirs and developed its composition by 3 component mixing of surface freshwater, saltwater (of ultimately marine origin) and a water–rock reaction component. In contrast to the thermal water, CO₂-rich mineral water, tapped and bottled from many wells in the Black Forest, has low salinities but a TDS distribution similar to that of thermal water. It developed its chemical composition entirely by reaction of CO₂-rich water with the gneissic or granitic aquifer rock matrix. Particularly important is the contribution of various plagioclase dissolution and weathering reactions that may, at some locations, involve precipitation and dissolution of secondary calcite. Sodium/Ca ratios of water and of rock forming plagioclase in the basement rocks suggests that plagioclase weathering is strongly incongruent. Calcium is released to the water, whereas Na remains fixed to the albite feldspar component.The major element composition of 192 water samples used in this study also indicates a clear vertical stratification of the type of water chemistry; Ca–HCO₃ near the surface, Na–Ca–HCO₃–SO₄ at intermediate depth and Na–Ca–Cl at great depth.The mean permeability of Black Forest granite is about K=10⁻⁶ m/s; it is significantly lower in gneisses (gneiss: mean K=5×10⁻⁸ m/s) leading to focused flow through granite. Highly permeable fracture and fault zones, particularly in granite, are utilized by high-TDS saline deep groundwater as ascent channels and flow paths. Although spatially closely associated, the topography driven upwelling system of saline deep water and the near-surface flow system of CO₂-rich mineral waters are hydraulically and chemically unconnected.     

沉积盆地流体活动及其成岩响应

盆地流体活动通过改变成岩场的温压和孔隙水介质条件,进而影响到盆地内成岩作用序列、水—岩相互作用以及储层孔隙变化。对于碎屑岩而言,流体活动仅能导致母岩中少部分矿物的溶蚀以及孔隙内溶解与沉淀作用发生,富含二氧化碳和有机酸的流体活动为次生孔隙发育提供条件,超压环境下流体幕式释放既可导致超压体内次生孔隙的发育,又可以导致热流体活动影响区域内浅部储层的成岩异常;对于碳酸盐岩而言,由于碳酸盐岩具有很强的溶解性,盆地流体活动导致碳酸盐岩储层组构及空间发生巨大的变化,其中天水的下渗以及与深部热液或热流体沿断裂或裂缝释放均可导致碳酸盐岩成分、组构、储集空间发生根本性变化,故与盆地流体活动密切相关的风化壳型岩溶储层和构造热液白云岩储层构成碳酸盐岩中最为重要的储层类型。然而,盆地流体活动及其成岩响应研究仍存在许多亟待解决的难点问题,急待深入的研究探索。     

Vadose zone controls on weathering intensity and depth: Observations from grussic saprolites

An investigation of vadose zone weathering processes has been undertaken on grussic saprolites developed on Californian granitoids. Preliminary results indicate strong climatic control, through infiltration, on the depth and intensity of weathering. At sites with higher infiltration, the vadose zone is comprehensively altered to grussic saprolite and saprock. Conversely, lower infiltration sites display only thin grussic saprolites, strongly influenced by rock texture. Both vadose zone and weathering depth appear to be governed by local base level, and vadose zone hydrology exerts a fundamental control on the effective operation and relative dominance of the key weathering reactions. In zones of matrix permeability, oxidation of biotite comprehensively disaggregates the rock but results in little mass loss and clay mineral formation. Conversely, the higher transient flow rates that characterize zones of fracture permeability result in plagioclase hydrolysis, significant mass losses and accompanying clay mineral formation. A variable hydrological regime may also contribute to high partial pressures of O₂ in vadose zone pore waters and pore spaces, thereby enhancing the oxidative environment and further predisposing grussic saprolite formation.     

Strontium as a tracer of weathering processes in a silicate catchment polluted by acid atmospheric inputs, Strengbach, France

This paper determines the weathering and atmospheric contributions of Ca in surface water from a small spruce forested silicate catchment (N–E France) receiving acid atmospheric inputs. The bedrock is a granite with K-feldspar and albite as dominant phases. The calcium content in plagioclase is low and the Ca/Na ratio in surface water is high, reflecting other sources of calcium from those expected from the weathering of major mineral phases. The biotite content is low. Only traces of apatite were detected while no calcite was found in spite of a major hydrothermal event having affected the granite. The strontium isotopic ratio ⁸⁷Sr/⁸⁶Sr and Sr content was used as a tracer of weathering and was determined in minerals and bulk bedrock, open field precipitation, throughfall, soil solution, spring and stream water. The Sr isotopic ratio of the reacting weathering end-member was predicted by simulating the alteration of the granite minerals by incorporating strontium into the water–rock interaction kinetic code KINDIS. In the early stages of water–rock interaction, K-feldspar and biotite strongly influence the isotopic composition of the weathering solution whereas, the Na-rich plagioclase appears to be the main long-term reactive weathering end-member. Approximately 50% of dissolved Sr in streamwater are atmospherically derived. The ⁸⁷Sr/⁸⁶Sr ratios of exchangeable Sr in the fine fraction at 1-m depth from a soil profile indicate that the amount of exchangeable Sr seems essentially controlled by atmospheric inputs. The exception is the deep saprolite where weathering processes could supply the Sr (and Ca). Na-Plagioclase weathering obviously control the chemistry and the isotopic composition of surface waters. The weathering of trace mineral plays a secondary role, the exception is for apatite when plagioclase is absent. Our hydrochemical, mineralogical and isotopic investigations show that a major part of the strong Ca losses detected in catchment hydrochemical budgets that result from the neutralization of acid precipitation has an atmospheric origin. Consequently, in the long term, in such areas, the availability of such an exchangeable base cation might be strongly limited and surface waters consequently acidified.     

Mineralogical sources of the buffer capacity in a granite catchment determined by strontium isotopes

The role of different minerals in base cation release and thus the increase of buffering capacity of groundwater against acid deposition is controversially discussed in the literature. The ⁸⁷Sr/⁸⁶Sr ratios and base cation concentration were investigated in whole rock leachates, mineral separates, precipitation, soil solution, groundwater and stream water samples in the Lehstenbach catchment (Germany) to identify the weathering sequence of the granite bedrock. Three different approaches were followed in parallel. It was assumed that the contribution of different minerals to base cation supply of the groundwater with increasing weathering intensity would be observed by investigating (1) unweathered rock leachates, deep groundwater and shallow groundwater, (2) groundwater samples from new groundwater wells, reflecting the initial weathering of the drilled bedrock, and groundwater from wells that were drilled in 1988, (3) stream water during baseflow, dominated by deep groundwater, and stream water during high flow, being predominantly shallow groundwater. Whereas the first approach yielded consistent patterns, there was some evidence that groundwater from the new wells initially reflected contamination by the filter gravel rather than cation release in an initial stage of weathering. Time series samples of stream water and groundwater solute concentrations and isotope ratios turned out to reflect varying fractions of soil water and precipitation water at baseflow and high flow conditions rather than varying contributions of different minerals that prevail at different stages of granite weathering.     

鲁西北地区理疗热矿水的形成条件及找矿靶区

鲁西北地区赋存发育碳酸盐岩类裂隙-岩溶型与砂岩类裂隙-孔隙型2种理疗热矿水,碳酸盐岩类裂隙-岩溶型理疗热矿水主要为氟·锶水;砂岩类裂隙-孔隙型理疗热矿水主要为锶水和溴·锶水。根据对理疗热矿水形成条件的分析,研究区内的鲁西地块阳谷-齐河凸起与坳(凹)陷区内的顶部风化壳岩溶发育的基底凸起(潜山)是碳酸盐岩类裂隙-岩溶型理疗热矿水的找矿靶区;华北坳陷区内深大断裂及坳(凹)陷边缘较大断裂附近的次级构造发育区是砂岩类裂隙-孔隙型理疗热矿水的找矿靶区。