电感耦合等离子体质谱法测定高海拔地区地热水中的微量元素

西藏地区地热水矿化度较高,且西藏地区海拔高分压低,造成电感耦合等离子体质谱/发射光谱仪(ICP-MS/OES)的工作条件与低海拔地区不同,因此测定样品时无法采用与低海拔地区相同的测定方法。本文通过优化仪器的工作条件、加入内标元素和建立干扰校正方程等方法,消除了低分压和高矿化度的影响,建立了ICP-MS同时测定高海拔地区地热水中的12种微量元素的方法,并对地热水中的放射性元素铀进行检测。测定元素校准曲线的相关系数都在0.9995以上,方法检出限为0.012~0.128μg/L,相对标准偏差(RSD)为1.2%~6.8%,样品加标回收率为95.7%~106.5%。结合本课题组前期的研究成果,本文提出,ICP-MS法更适合较高矿化度地热水中微量和痕量元素的测定,ICP-OES法则适用于主量元素的测定,两种方法的结合,可建立高海拔地区地热水的分析技术体系。     

西藏申扎县地热活动带水文地球化学特征

论文探讨了西藏申扎县南部地堑系内温泉的水文地球化学特征及热源问题。研究发现地下水受到下部岩浆活动的影响增温,其温度和二氧化碳分压值在区内分布有差异,对岩层的溶滤强度有影响。热泉、温泉水的化学类型与其所处的的地质背景和物质来源有密切关系。通过对比地热水中的Br/I、Cl/Br、γNa/γCl比值系数与正常海水Br/I(1300)、Cl/Br(300)、γNa/γCl(0.85)比值系数,得出申扎县微温泉、地那热泉为深层残余海水。地热水中富含HBO2反映地下水受岩浆活动影响,同时也导致区域地下水中富含F、Cl、Li、Rb、Cs等元素。通过对Si O2溶解曲线的研讨,确定其热储性质为中温地热系统,热储埋深约为17km。     

西藏申扎县地热活动带水文地球化学特征

论文探讨了西藏申扎县南部地堑系内温泉的水文地球化学特征及热源问题。研究发现地下水受到下部岩浆活动的影响增温,其温度和二氧化碳分压值在区内分布有差异,对岩层的溶滤强度有影响。热泉、温泉水的化学类型与其所处的的地质背景和物质来源有密切关系。通过对比地热水中的Br/I、Cl/Br、γNa/γCl比值系数与正常海水Br/I(1300)、Cl/Br(300)、γNa/γCl(0.85)比值系数,得出申扎县微温泉、地那热泉为深层残余海水。地热水中富含HBO2反映地下水受岩浆活动影响,同时也导致区域地下水中富含F、Cl、Li、Rb、Cs等元素。通过对Si O2溶解曲线的研讨,确定其热储性质为中温地热系统,热储埋深约为17km。     

贵州息烽温泉地质成因分析

贵州息烽温泉富含氡、锶等对人体有益的微量元素。在分析息烽温泉形成的地质背景基础上,利用构造地质、水化学和稳定同位素等手段,对温泉的成因进行了研究。研究表明,息烽温泉水源为大气降水,热源为深循环加热,循环深度约3 000m,热储温度达100℃以上。在洋水背斜北倾伏端,地热水受碎屑岩阻隔并混合浅表地下水而排出。为保障息烽温泉的可持续性,其周边磷矿勘探、开采的同时,应加强地热水的勘查和保护工作。     

贵州息烽温泉控热推覆构造的发现及成因研究

根据近年来磷矿深部勘探资料,对贵州息烽温泉的构造地质条件及地热特征开展研究,获得了有关温泉地质成因的新认识。①由洋水背斜、安清断层(F₁)和温泉断层(F₂)组成的叠瓦状逆冲推覆构造体系,构成了息烽温泉地热水系统的主体及边界,该控热构造体系内地表构造与地腹构造并不统一,老地层盖在新地层上,构成顶、底两层叠置的多个热储单元,这些热储单元是地热水形成和运移的良好场所。②安清断层(F₁)使多个热储单元直接接触,从而具有密切的水力联系,为导水、导热的良好通道; 温泉断层(F₂)构成了息烽温泉区地热水系统的边界。③大气降水沿断裂通道下渗至深部的碳酸盐岩热储层中,吸收热量形成地热水,在高温高压条件下,向洋水背斜核部进行迁移,受上覆寒武系碎屑岩盖层的保护和温泉断层的限制,形成洋水背斜西翼和北端的地热资源有利富集区,最后受分支断层阻挡而自然岀露。     

重庆市东温泉地热地质特征及成因模式探讨

重庆市东温泉是以三叠系嘉陵江组灰岩为热储层,以三叠系上统须家河组和侏罗系红色砂泥岩地层为盖层,以三叠系飞仙关组砂页岩为下部隔热层的层状深循环型地热系统。本文从地热显示、水文地球化学、热储结构及热水动态变化等方面分析了该市东温泉地热地质特征,并从热源及补径排条件等方面探讨了东温泉成因模式。结果可知:东温泉区共有天然温泉11处,人工钻井温泉6处,水温27℃~53℃,水质类型为SO4-Ca型,地热水热源主要来自地热增温,地热水补给源于大气降水。其成因模式主要为:大气降水在桃子荡背斜槽谷的灰岩出露区下渗形成浅层地下水,部分浅层地下水顺灰岩岩层的孔隙裂隙向深部运移,同时地热水顺构造线方向由南向北径流,在运移过程中不断溶解和富集矿物盐及微量元素,并以传导型的地热增温方式提高深部循环水的温度,在五布河流深切峡谷地段出露成泉,或以人工钻井形式排泄。研究结果对今后该区地热资源的合理开采及温泉开发远景规划等具有一定的指导意义。     

藏南茶卡—曲卓木温泉水化学特征与成因机理

位于青藏高原南部的茶卡—曲卓木区域地质条件复杂,构造发育,水热活动强烈,区内温泉展布主要受区内断裂控制,并呈现出分区发育的特征。本文以区内主要的茶卡水热活动区和曲卓木水热活动区的温泉为研究对象,通过对水热活动区地质、水文地质条件和温泉出露特征开展野外调查,并对温泉和地表水进行采样分析,并运用水文地球化学分析方法,对区内温泉水岩反应过程和补给来源进行了分析研究,同时利用SiO2、阳离子地热温标和硅-焓混合模型方法计算了深部热储温度。基于以上研究成果,进一步分析了区内温泉的形成机制,建立了区内温泉成因模式概念模型,并对地热资源量进行了评价,结果表明：(1)茶卡水热活动区温泉温度普遍高于曲卓木水热活动区,其温泉水化学类型为Cl-Na型水,曲卓木水热活动区则主要为SO₄-Cl-Na型水;(2)大气降水为主要补给来源,补给高程范围在4 517～5 186 m;(3)茶卡水热活动区、曲卓木水热活动区热储温度分别为208～251℃、80～102℃,冷热水混合比分别为33%～47%、34%～49%;(4)研究区内天然地热水的年可开发能量达到8.50×10¹³...     

江苏东海温泉热储温度估算

以东海温泉为例,依据8个热水样品的水化学分析数据,讨论了区域地质背景下热储温度的估算。分析认为:东海温泉为同源的地热水,热水在上升过程中发生冷水混合作用;对比不同地热温标的适用条件,分别采用Na-K-Mg三角图法、硅温标混合模型方法计算热储温度。结果显示:2种方法的计算结果较为接近,东海温泉的热储温度在153~170℃之间。     

青岛即墨温泉喷流沉积物及其沉积模式

本文应用XRD测试技术和岩石地层学方法、生物地层学方法，将即墨温泉地热区第四系划分为层Ⅰ、层Ⅱ1、层Ⅱ2和层Ⅲ，根据沉积物中所含石膏、岩盐等与温泉地热水相关的自生矿物的空间分布和以直隶小旋螺(Gyraulus chihliensis)为代表的腹足类陆生软体动物化石，以及以土星介(Illyocypris sp.)为代表的节肢动物介形虫化石的空间分布，确立Ⅱ1层为温泉喷流沉积，是第四纪活动断裂控制的地球化学异常的产物，以此建立起温泉喷流沉积模式。     

山东即墨温泉资源开发利用与可开采水量评价

山东即墨温泉是胶东三大氯化物温泉之一,为中氡地热水,具有较高的医用价值。目前温泉可采资源量占总量的56%,开采潜力较高,但由于旅游业的大力发展,大规模开发地热水造成地下水水位从1992年至今水位下降近20 m,矿化度及氯、钠离子变化不大,说明监测井位置海水入侵程度较低。同时,通过计算得出,即墨温泉可利用热能资源量1. 28×1015 J,相当于8. 79×104 t标准煤的热量,地下热水储量为0. 68×108 m3,地下水可采资源量为1075. 31 m3/d。并通过modflow软件模拟开发条件进行评价,提出了月开采量的合理化建议：即每年12月~次年3月开采量为1450 m3/d,4月~6月开采量为450 m3/d,7月~11月开采量为100 m3/d。     

Determination of total sulfur in geothermal water by inductively coupled plasma-atomic emission spectrometry

Sulfur speciation and concentration in geothermal water are of great significance for the research and utilization of the water resources. In most situations, it is necessary to determine the total sulfur in geothermal water. In this study, the method was established for the determination of determining total sulfur content — the inductively coupled plasma-atomic emission spectrometry (ICP-AES), with the wavelength of 182.034 nm selected in spectral line of sulfur. It was identified that the optimal working conditions of the ICP-AES instrument were 1 200 W for high frequency generator power 9 mm for vertical observation height, 0.30 MPa atomizer pressure, and 50 r/min analytical pump speed. The matrix interference of the method was eliminated by the matrix matching method. Using this method, sulfur detection limit and minimum quantitative detection limit were 0.028 mg/L and 0.110 mg/L, respectively, whilst the linear range was 0.0–100.0 mg/L. The recovery rate of sample was between 90.67% and 108.7%, and the relative standard deviation (RSD) was between 0.36% and 2.14%. The method was used to analyze the actual samples and the results were basically consistent with the industry standard method. With high analysis efficiency, the method has low detection limit and minimum quantitative detection limit, wide linear range, good precision and accuracy, and provides an important detection method for the determination of total sulfur in geothermal water.     

粉末压片制样-波长色散X射线荧光光谱法测定斑岩型钼铜矿中主次量元素钼铜铅锌砷镍硫

采用粉末压片制样,波长色散X射线荧光光谱法测定西藏某斑岩型钼铜矿中7个主次量元素Mo、Cu、Pb、Zn、As、Ni、S。选择钼矿石、铜矿石国家标准物质及自配标准物质建立工作曲线,使用康普顿散射线作内标,同时采用经验系数法校正基体效应及粒度效应。方法经国家标准物质、自配标准参考物质验证,测定值与标准值吻合,方法分析精密度(RSD,n=12)小于2.18%,与化学法相比,样品不需进行化学前处理,操作简单、快速、准确度高、精密度好,能满足钼铜矿的实际分析需要。利用国家标准物质配制合成了7个校准标准样品,有效地解决了方法建立过程中标准样品种类和数量不足的问题。     

藏北温泉盆地地热田水文地球化学特征研究

藏北温泉盆地地热资源丰富,但研究程度较低。为查明温泉盆地地热资源赋存状态及热源来源,揭示热循环机理,定量评估研究区热储温度、冷水混入比例、热循环深度等,利用温泉盆地地热田共18组温泉水样进行水化学分析,进行定量计算。结果表明:温泉盆地温泉水水化学类型主要为Ca-HCO3?SO4型。温泉盆地地下热水在向上运移过程中,受浅层地下水的混合作用影响,使得热水变为“未成熟水”。温泉水中文石、方解石等钙质热液的饱和度指数大于0。热储温度60.93~96.52 ℃,热循环深度3 238.06~5 215.28 m,冷水混入比例在20.97%~70.19%之间。硅-焓模型计算出未混入冷水时深部热储温度在81.94~167.26 ℃之间,热储循环深度4 405.56~9 145.56 m。      

Origin of the enrichment of B and alkali metal elements in the geothermal water in the Tibetan Plateau: Evidence from B and Sr isotopes

Geothermal fields distributed in the southern Tibet Plateau rifts such as Yangbajing - Dangxiong basin, and the Yaluzangbu suture are characterized by intensive hydrothermal activity and high enrichment of trace elements (e.g., Li, Rb, Cs, B and Br) in geothermal springs. However, the origin of these elements and their enrichment mechanisms in those geothermal waters remain unclear. This study presents data for the enriched elements, incompatible elements, and B and Sr isotopes, in the geothermal water in the Tibetan Plateau and compares them with some typical geothermal fields worldwide, in an attempt to provide new insights into the origin and mechanism of the enrichment of these trace elements. The results indicate that all geothermal water samples from the Tibetan Plateau show more negative δ¹¹B values than those from local precipitation and rivers. Considering the wide existence of a high-conductivity zone in the middle or even upper-crust interpreted to correspond to re-melt magmatic fluids in the Tibet, the main sources of the typical chemical composition of geothermal waters in the Tibetan Plateau can be classified into two main types: residual magmatic fluids derived from crustal partial remelting and deep circulated groundwater modified by water–rock interactions. In particular, the possible source of magmatic fluids may play a more significant role for special geochemical compositions of geothermal water in the Tibet. Such resources are beneficial for the development and utilization of the geothermal water itself and also serve as a stable source for feeding the salt lake resources.     

电感耦合等离子体发射光谱法测定地热水中的硫化物

地热水中的硫化物(H_2S、HS~-和S~(2-))通常受到硫酸根、亚硫酸根、硫代硫酸根等硫元素的共存干扰,并且硫化物具有热、光、氧不稳定性,在水样保存、前处理、标准溶液配制等环节影响着测试的准确度和精密度。本文在现场采集的地热水水样中加入乙酸锌及氢氧化钠,使硫化物形成硫化锌沉淀而与溶液分离,将此沉淀溶于双氧水和逆王水,使低价态的S2-氧化成稳定的SO_4~(2-),选择易于纯化且性质稳定的硫酸钠配制硫标准储备液,以182.624 nm谱线作为硫元素分析谱线,应用电感耦合等离子体发射光谱法测定出地热水样中的硫化物含量。硫的浓度在0.1~100 mg/L范围内与其发射强度呈线性(相关系数为0.9994);方法检出限为0.009 mg/L,相对标准偏差(n=11)低于1.80%,实际水样中硫化物的加标回收率介于99.0%~103.0%。与前人相关测试方法相比,本方法的技术指标具有优势。     

O,H,and Sr isotope evidence for origin and mixing processes of the Gudui geothermal system,Himalayas,China

Tho Gudui geothermal field records the highest temperature at equivalent borehole depths among the lainland hydrothermal systems in mainland China.Located about 150 km southeast of Lhasa City,the capital of Tibet,the Gudui geothermal field belongs to the Sangri-Cuona rift belt,also known as the Sangri-Cuona geothermal belt,and is representative of the non-volcanic geothermal systems in the Himalayas.In this study,oxygen-18 and deuterium isotope compositions as well as ~(87)Sr/~(86)Sr ratios of water samples collected from the Gudui geothermal field were characterized to understand the origin and mixing processes of the geothermal fluids at Gudui.Hydrogen and oxygen isotope plots show both,deep and shallow reservoirs in the Gudui geothermal field.Deep geothermal fluids are the mixing product of magmatic and infiltrating snow-melt water.Calculations show that the magma fluid component of the deep geothermal fluids account for about 21.10%-24.04%;magma fluids lay also be a contributing source of lithium.The linear relationship of the ~(87)Sr/~(86)Sr isotopic ratio versus the 1/Sr plot indicates that shallow geothermal fluids form from the mixing of deep geothermal fluids with cold groundwater.Using a binary mixing model with deep geothermal fluid and cold groundwater as two end-members,the nixing ratios of the latter in most surface hot springs samples were calculated to be between 5% and 10%.Combined with basic geological characteristics,hydrogen and oxygen isotope characteristics,strontium concentration,~(87)Sr/(86)Sr ratios,and the binary mixing model,we infer the 6 th-Class Reservoirs Evolution Conceptual Model(6-CRECM) for the Gudui geothermal system.This model represents an idealized summary of the characteristics of the Gudui geothermal field based on our comprehensive understanding of the origin and mixing processes of the geothermal fluid in Gudui.This study may aid in identifying the geothermal and geochemical origin of the Gudui high-temperature hydrothermal systems in remote Tibet of China,whose potential for geothermal development and utilization is enormous and untapped.     

高岭土中全硫量快速测定方法

采用碳酸钠一氧化镁半熔融一氯化钡滴定法测定高岭土中的硫含量。试样用碱性熔荆半熔，熔块以水浸取，将转化为硫酸盐后的滤液，以玫瑰红酸钠为指示剂，在pH为5．5．7．0的条件下，用氯化钡标准溶液进行滴定。测定结果的RSD=2．47％（n=5），加标回收率为95．2％-100．3％。改进后的方法已用于高岭土中全硫量的测定，结果与国标重量法相符。     

Hydrochemistry and H-O-C-S Isotopic Geochemistry Characteristics of Geothermal Water in Nyemo-Nagqu, Tibet

Nyemo-Nagqu, Tibet, is rich in high-temperature geothermal resources. The geothermal fields in Yangbajain and Yangyi as well as 11 unexplored geothermal fields along the geothermal belt from Nyemo to Nagqu were systematically investigated and the hydrochemistry data were collected from the whole field. Meanwhile, H-O-C-S isotope data were obtained for the new fields, and H-O isotope data for the Yangbajain and Yangyi fields. A comparison of the Nyemo-Nagqu geothermal fields with those in the Yangbajain area shows that the types of high-temperature geothermal water are dominated by Cl-Na and Cl·HCO_3-Na, while the types of medium-high-temperature geothermal water are dominated by HCO_3-Na. The concentrations of Li, F, SiO_2, and HBO_2 in the geothermal water are positively correlated with Cl content, indicating possible mixing with magma water. The reservoir temperatures range from 90 to 270°C by geothermometers. Slight drifting of ~(18)O was recorded at the Dongweng and Nyingzhong high-temperature geothermal fields, while more significant drifting was recorded at Gulu. The geothermal water is mainly replenished by atmospheric precipitation. The low tritium contents(1 TU) of the geothermal water from Nyingzhong, Gulu, and Luoma indicate that it is mainly replenished by sub-modern(prior to 1952) water, while the high tritium content(8.4 TU) in Yuela implies modern water replenishment. Other geothermal fields are replenished by a mix of sub-modern fresher water. The isotopic data in this study show that the carbon and sulfur in the geothermal water originates mainly from sediment leaching, with some of the carbon and sulfur having a deep origin.     

西藏地热系统B、Li、Rb和Cs元素空间分布规律与超常富集机制

西藏地热资源异常丰富,属于地中海—喜马拉雅地热带的重要组成部分。地热系统最为典型的地球化学特征是大部分地热泉或与之相应的泉华沉积物超常富集B、Li、Rb、Cs等元素,具有重要的矿产资源意义。有关这些特征元素来源与水化学演化成因机制,长期存在争议,在理论上缺乏系统论述。本文基于多年野外考察与数据积累,以及对前人研究成果的系统总结,提出了西藏地热系统特征元素组合与富集成因模式,宏观板块构造与微观地球化学分布规律结合,揭示了其成因机制。数据综合分析表明,B、Li、Rb、Cs元素在空间上的分布富集规律总体具有同步性,主要集中分布于雅鲁藏布江缝合带与南北向断裂带交汇区的高温地热系统。B同位素、元素组合、水循环特征及大量地球物理证据表明物源受控于岩浆残余流体,水-岩作用难以作为唯一物源支撑地热系统如此大规模的特征元素超常富集。结论提出西藏地热系统超常富集的元素受控于板块俯冲碰撞、地壳局部重熔、重熔型岩浆流体分异演化、地下水深循环等一系列内外生地质耦合作用过程。本文对西藏地热系统元素超常富集成因机制的解释,有利于增强人们对高温地热系统除水资源与热能意义之外,也同时关注矿产资源价值,实现“水-热-矿”于一体的系统理解,也对未来正确评价地热水体或沉积物矿产资源价值有理论指导意义。     

硫脲络合-火焰原子吸收光谱法同时测定银精矿中的铜和银

在高氯酸-硫脲介质中用原子吸收光谱法同时测定地质及选冶样品中银和铜已有文献报道;但在王水-硫脲介质中存在铜对银的测定干扰.本文采用盐酸-氢氟酸-硝酸-高氯酸四酸溶矿,王水提取、硫脲络合,用火焰原子吸收光谱法对银精矿中铜、银进行连续测定.通过筛选不同的样品消解方法,试验了硫脲介质浓度的影响,对共存元素的干扰进行消除.结果表明:四酸溶矿效果最好;通过加入过量的硫脲并控制其浓度在20 g/L以内,使溶液中银的白色沉淀与硫脲生成可溶的Ag[SC(NH2)2]3+配离子,消除了铜对银测定的干扰.该方法用于样品分析,相对标准偏差RSD(n =6)铜为1.20％～2.11％,银为0.61％ ～1.18％;加标回收率铜为96.5％ ～ 107.0％,银为97.3％ ～ 104.7％.测定值与碘量法、火试金法结果相符.本法具有简单、实用、成本低等优点,可满足银精矿选矿工艺生产的需要.