Increase in thermal groundwater due to a flowing well near the Songshan hot spring in Beijing,China

The Songshan hot spring occurs in granite in Yanqing County in northwestern Beijing, China. TDS of the hot water ranges from 459 to 475 mg/L and pH varies between 8.6 and 9.13. The water is of Na–SO₄ type. Isotopic analyses indicate that the hot spring is meteoric in origin and receives recharge from precipitation in the northern and northwestern granite mountain with elevation of about 1,600–1,800 m. The depth of circulation of the thermal groundwater is estimated to be 2,240 m below the spring’s threshold and the temperature of the geothermal reservoir, 76°C. The residence time of the thermal groundwater is estimated to be about 52 years. A flowing well near the spring has chemical compositions and formation conditions similar to the spring. The discharge of the flowing well is approximately eighteen times larger than that of the spring and the residence time of the former (about 15.4 years) is about three times smaller than that of the latter. Although the well and spring are close to each other, the well’s larger flow rates, indicated residence time and high hydraulic head suggest that the well taps a separate, but genetically similar flow system.     

Overview on hydrothermal and hot dry rock researches in China

Geothermal energy is a precious resource, which is widely distributed, varied, and abundant. China has entered a period of rapid development of geothermal energy since 2010. As shallow geothermal energy promoting, the depth of hydrothermal geothermal exploration is increasing. The quality of Hot Dry Rock (HDR) and related exploratory technologies are better developed and utilized. On the basis of geothermal development, this paper reviews the geothermal progress during the “12th Five-Year Plan”, and summarizes the achievements of hydrothermal geothermal and hot dry rocks from geothermal survey and evaluation aspects. Finally, the authors predict the development trend of the future geothermal research to benefit geothermal and hot dry rock research.     

Isotopes of deuterium and oxygen-18 in thermal groundwater in China

Compositions of deuterium and ¹⁸O isotopes of 90 representative samples indicate that thermal groundwater in most parts of China is meteoric in origin. Latitude, altitude, and continent effects have significant bearing on the values of δD and δ¹⁸O of the hot water samples. Oxygen-18 shift is not significant in most of the thermal groundwater, especially the hot water of low-to-moderate temperature. Slight oxygen-18 shift is only found in some hot springs of high temperature in Tibet and western Yunnan and in thermal groundwater of low-to-moderate temperature in the deep-seated carbonate aquifers in the northern North China Plain (including the Tianjin area). Near-surface boiling may causes the shift of the former and the latter may be attributed to exchange of oxygen-18 between water and carbonates in the geothermal systems of taphrogenic basin-type. Hot springs in Tibet and western Sichuan have very low contents of δD and δ¹⁸O, possibly due to recharge of precipitation and snow-melting water of extremely depleted δD and δ¹⁸O values at high latitudes of several thousands of meters.     

Geological characteristics and analysis of hydrothermal genesis in the Suijiang-1 well in Yunnan Province,China

The geothermal water hydrochemistry and isotopic characteristics of boreholes in the Suijiang-1 well in Yunnan Province were studied based on the actual drilling geology, regional geological structure and hydrogeological conditions. The analysis results show that the geothermal water is SO_4-Ca·Mg type, the recharge elevation is 1 381-1 646 m, the recharge source is atmospheric precipitation, the geothermal reservoir temperature is 42-45 ℃, and the geothermal water is controlled by lithology and geological structure conditions of study area. Atmospheric precipitation enters the groundwater circulation system through the surface karst form of the Wujiaobao anticline, northwest-southeast tensile faults, fissures and karst depression, and geothermal water formed through the rising deep cycle water temperature, then blocked by the double rivers' fault zone and drilling explosion.     

Geological characteristics and analysis of hydrothermal genesis in the Suijiang-1 well in Yunnan Province,China

The geothermal water hydrochemistry and isotopic characteristics of boreholes in the Suijiang-1 well in Yunnan Province were studied based on the actual drilling geology, regional geological structure and hydrogeological conditions. The analysis results show that the geothermal water is SO4-Ca?Mg type, the recharge elevation is 1 381-1 646 m, the recharge source is atmospheric precipitation, the geothermal reservoir temperature is 42-45 ℃, and the geothermal water is controlled by lithology and geological structure conditions of study area. Atmospheric precipitation enters the groundwater circulation system through the surface karst form of the Wujiaobao anticline, northwest-southeast tensile faults, fissures and karst depression, and geothermal water formed through the rising deep cycle water temperature, then blocked by the double rivers’ fault zone and drilling explosion.     

四川稻城地区温泉流体地球化学特征及地震活动性分析

稻城地区位于青藏高原东南缘的川滇地块北部,为揭示该区域温泉流体地球化学特征以及其和地震活动性之间的关系,本次研究采集了稻城地区6个温泉的水样以及逸出气体样品。对温泉水中离子组分和浓度,温泉逸出气体组分及气体同位素进行了测试,得到以下认识。研究区温泉水化学类型主要为HCO₃-Na和HCO₃-Na·Ca型,通过阳离子温标估算热储温度在74℃~159℃之间,循环深度在2.2 km~5.0 km之间。温泉气体中CO₂主要是由储层中的碳酸盐岩受热分解或溶解产生的,氦来自幔源组分的比例较低,在0.4%~2.4%之间,研究区的温泉是由沿断裂带渗入的大气降水经地壳深部的热源加热形成的。在稻城地区,循环深度以及幔源气体贡献率等不同的温泉流体地球化学特征与地震活动性之间有很好的对应关系,并且研究区地震活动性要弱于周缘鲜水河断裂地区等深部流体上涌地区。同时在区域尺度上,未来位于断裂交汇部位的稻城仲堆温泉一带的地震活动性最值得关注。

     

Geochemical constraint on origin and evolution of solutes in geothermal springs in western Yunnan,China

Geothermal resources are very rich in Yunnan, China. However, source of dissolved solutes in geothermal water and chemical evolution processes remain unclear. Geochemical and isotopic studies on geothermal springs and river waters were conducted in different petrological-tectonic units of western Yunnan, China. Geothermal waters contain Ca–HCO₃, Na–HCO₃, and Na (Ca)–SO₄ type, and demonstrate strong rock-related trace elemental distributions. Enhanced water–rock interaction increases the concentration of major and trace elements of geothermal waters. The chemical compositions of geothermal waters in the Rehai geothermal field are very complicated and different because of the magma chamber developed at the shallow depth in this area. In this geothermal field, neutral-alkaline geothermal waters with high Cl, B, Li, Rb Cs, As, Sb, and Tl contents and acid–sulfate waters with high Al, Mn, Fe, and Pb contents are both controlled by magma degassing and water–rock interaction. Geothermal waters from metamorphic, granite, and sedimentary regions (except in the Rehai area) exhibit varying B contents ranging from 3.31 mg/L to 4.49 mg/L, 0.23 mg/L to 1.24 mg/L, and <0.07 mg/L, respectively, and their corresponding δ¹¹B values range from −4.95‰ to −9.45‰, −2.57‰ to −8.85‰, and −4.02‰ to +0.06‰. The B contents of these geothermal waters are mainly controlled by leaching host rocks in the reservoir, and their δ¹¹B values usually decrease and achieve further equilibrium with its surrounding rocks, which can also be proven by the positive δ¹⁸O-shift. In addition to fluid–rock reactions, the geothermal waters from Rehai hot springs exhibit higher δ¹¹B values (−3.43‰ to +1.54‰) than those yielded from other areas because mixing with the magmatic fluids from the shallow magma. The highest δ¹¹B of steam–heated waters (pH 3.25) from the Zhenzhu spring in Rehai is caused by the fractionation induced by pH and the phase separation of coexisting steam and fluids. Given the strong water–rock interaction, some geothermal springs in western Yunnan show reservoir temperatures higher than 180 °C, which demonstrate potential for electricity generation and direct-use applications. The most potential geothermal field in western Yunnan is located in the Rehai area because of the heat transfer from the shallow magma chamber.     

腾冲地热区高温热泉水中稀土元素特征

腾冲地热区位于印度-欧亚板块碰撞带东北缘,构造和岩浆活动频繁,地热作用明显,热泉广泛分布,是现代热泉研究的天然实验室。热泉水中的稀土元素特征是指示浅层水岩反应的重要指标。由于热泉水中稀土元素含量较低且变化范围大,腾冲地区热泉水稀土元素组成的报道比较罕见。本文尝试研究了腾冲高温热泉水中稀土元素组成特征,并与美国内华达州贝奥沃韦地热田和加利福尼亚希伯地热田热泉水的稀土元素特征进行了对比。本文选取腾冲地区的高温热泉,应用ICP-MS,测试了热泉水中稀土元素。分析结果表明热泉水中稀土元素含量相对较低且变化范围较大,其变化范围为球粒陨石的10-5～10-2倍。稀土元素球粒陨石标准化配分模式整体为轻微右倾型或平坦型,显示轻重稀土分异不明显;δEu既有正异常也有负异常;各热泉点热泉水稀土配分模式之间存在差异。虽然腾冲地热区热泉水的REE含量比美国贝奥沃韦地热田和希伯地热田热泉水的高10倍,两者之间的稀土元素分布特征具有一致性。热泉水中的δEu负异常为深循环的大气降水与具有负铕异常火山岩水岩反应的结果,正铕异常可能是由快速上返的大气降水与蒸发岩中的石膏反应导致。     

济南市岩溶泉域地下水化学特征与水环境演化

分析山东省济南市趵突泉泉域的岩溶地下水水化学特征与水环境,揭示各化学指标的区域分布特征、时间变化特征以及相互转化关系,总结出济南地区地下水环境现状与演化规律。结果表明:济南市岩溶地下水水化学类型自东南向西北沿流场方向为:HCO3?SO4-Ca→HCO3?SO4-Ca?Mg→HCO3-Ca→HCO3-Ca?Mg;地下水NO〖_3^-〗-N浓度总体呈增高趋势,总硬度和TDS浓度较高,农业种植区大量使用化肥农药和企业污染物的排放,是引起济南市岩溶地下水水环境问题的主要原因。      

北京城区地下热水结垢趋势的判断和分析

结垢天地下热水供暖系统运行中普遍存在的现象,对地下热水的腐蚀结垢趋势的计算和判断对于整个工艺运行的稳定性至关重要。本文以北京城区地热田10个代表性地热井为例,采用指数(雷兹诺指数和拉申中指数)判断法以及WATCH程序对地下热水的结垢趋势进行计算和判定,结果表明,城区地热田的大部分地下热水有结垢的可能性,导致结垢的主要矿物是方解石和温石棉。     

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。     

腾冲热海地热田热储结构与岩浆热源的温度

腾冲热海地区是一个由幔源岩浆侵入形成的地热田,地热流体排放受深浅不同的三组活动断裂控制,具多层地热储结构特征。气体、 同位素、 水化学地球化学温标显示,深层热储的温度约为250±7℃、中、浅层地热储温度的变化范围分别为241～190℃和195～154℃。根据岩浆来源CO     

河北秦皇岛市温泉堡温泉的形成与开发利用建议

秦皇岛市温泉堡附近有3处温泉。1号和2号温泉是燕山期花岗岩地下破碎带热水储集带的排泄点,3号温泉的出露受断裂控制,是下寒武统府君山组灰岩岩溶含水层的排泄点。地下热水矿化度小于260mg/L,F-含量达5mg/L以上,水化学类型属于Na·Ca-HCO3·SO4型。同位素研究结果表明,温泉的补给来源为大气降水,1号温泉水年龄约19a。利用SiO2温标法计算出热储温度为94.01℃;估算热水循环深度为2792.45m。温泉的天然放热量大于25.13×1013J/a,温泉堡地区的地热资源量达7.29×1014J以上。1号和2号温泉的开采量不宜超过其天然流量,3号温泉流量大,尚有开发潜力。     

金沙江-红河断裂带温泉气体地球化学特征

金沙江-红河断裂带是青藏高原东南缘地热活动强烈、地震活动水平高、各种矿产丰富的深大断裂带。为了探索该断裂带的温泉气体地球化学时空变化特征,2015年3月～2019年7月,经过5次野外考察,采集了54个温泉逸出气体样品,对其化学组分和氦、氖与碳的同位素变化的测试结果表明:(1)金沙江-红河断裂带内温泉气体氦同位素比值(3He/4He)变化范围是0.04～0.62Ra(Ra=空气3He/4He=1.39×10-6),计算获得的幔源氦最大比例达到7.5%,揭示该断裂带内的地质流体主要来自于壳源,幔源氦有从北向南呈现增加的趋势。以CO2为主要组分的温泉,其δ13CCO2值变化范围是-23.6‰～-1.9‰(vs. PDB)。结合区域地质条件分析,这些CO2主要来自三叠系灰岩,所占比例范围是70.1%～89.7%,而幔源CO2的比例最高可以达到4.2%。(2)金沙江-红河断裂带温泉气体的氢气浓度和氦同位素在三处断裂交汇区都出现高峰值,分别是金沙江断裂与巴塘断裂、中甸断裂与红河断裂、红河断裂与小江断裂和奠边府断裂的交汇处。与区域地震活动性的对比分析结果表明,金沙江-红河断裂带内深部流体上涌相对强烈的区域,深部流体对区域地震活动性具有重要的控制作用。     

腾冲温泉中Li-U-Au异常富集特征及其成因浅析

综合滇西腾冲1974年以来的调查研究文献资料发现,该区正在发育国内外罕见的现代热泉型铀、金、砷、锑、稀土、锂、汞、钨、氢等元素的异常富集系统。为总结温泉中锂、铀、金战略性金属元素异常富集特征,探索其共生富集机制,本文统计了腾冲57个温泉近50年报道的320个地球化学数据,初次系统梳理出温泉中锂、铀、金元素具以下典型特征：（1）3种金属元素集中在部分泉水中异常富集。锂、金主要富集于大滚锅,铀主要富集于珍珠泉和叠水河碳酸泉,温泉中锂和铀含量高于全省绝大多数温泉。（2）锂元素含量稳定、富集效率高、资源潜力大。热海地区温泉锂含量变异系数均低于30%,指示半个世纪来锂含量波动幅度小,锂“流而不衰”;有学者初步测算出全区温泉年溢出锂金属量达532.9吨,20年流失量即可超过一个小型锂矿。此外,381砂岩型铀矿床还存在铀“采而不尽”的现象,可能与泉水中新生铀的持续补给有关。在前人研究成果基础之上,新提出温泉中锂、铀、金的共生富集可能主要是在地核或其局部富集的此类元素沿“腾冲现代地幔柱”自下往上迁移,在地表温泉及其沉积物中不断聚集的结果,即“核源—地幔柱”成因。

     

我国北方岩溶泉域生态修复策略研究

我国北方岩溶分布面积广,岩溶泉水资源丰富,是岩溶区工农业及居民生活的优质供水水源。但在全球气候变化和采煤等强烈人类活动的叠加作用下,我国北方岩溶泉水流量衰减,水质恶化,岩溶泉域生态环境功能下降。通过合理、适度的人工干预,强化岩溶大泉的自然恢复机能,并最终实现泉域生态环境修复,是当前我国生态文明建设的先行区和重点领域。论文在分析研究晋祠泉断流原因的基础上,针对性地提出并科学地评估了汾河二库强化渗漏补给、泉域岩溶水关井压采、煤矿区保水限采、近源生态补水和远源河道渗漏补给等一系列措施及预期效果,以期推进晋祠泉域岩溶地下水生态环境得到根本性改善。该研究工作有望对我国北方岩溶大泉的生态修复形成示范效应,为遏制我国岩溶区生态恶化现象提供科学依据。     

北京及其西北邻区温泉

北京及其西北邻区有7个温泉,水温37-68℃,流量0．304-24．08 L／s,对皮肤病、关节炎和风湿病有一定的疗效。在过去的50年里,除了怀来暖泉温泉外,其余温泉的流量和水温有所下降,其中海淀温泉村温泉、北京小汤山温泉和张家口白庙温泉陆续继流,赤城汤泉温泉和塘子庙温泉水温下降3-5℃。造成流量下降甚至断流的原因主要是区域性降雨量的减少和温泉附近钻井过量开采地下热水。合理开发利用和保护温泉资源使之能可持续利用具有重要意义。     

西藏搭格架热泉型铯矿床年代学研究

西藏昂仁县搭格架地热田硅华中的铯达到超大型矿床规模,不同特征的热泉沉积或分布于冈底斯冰期冰碛物的外表或裂隙中,或覆于长马曲上游第5至第1级阶地及现代河床的不同部位.据热泉华野外分布的地貌部位和岩石学特征可将其分为6套.这6套泉华代表性样品的全溶法或等时线法U系测年结果表明：第1套泉华（钙华）形成于晚更新世晚期的末次冰期间冰阶晚期,相当于深海氧同位素第3阶段即MIS 3;第2套泉华（硅华）形成于中更新世晚期的倒数第二次冰期,相当于MIS 8～7;第3套泉华形成于晚更新世早期的末次间冰期,相当于MIS 5;第4套泉华（硅华）形成于晚更新世晚期的末次冰期间冰阶晚期至末次盛冰期早期,相当于MIS 3～2;第5套泉华（硅华）形成于晚更新世末期的末次盛冰期至全新世冰后期,相当于MIS 2～1;第6套泉华即现代硅华.参考前人的ESR年龄测定结果,可将搭格架热泉华的形成分为5个阶段：403～202ka BP,99ka BP左右,39～25ka BP,17～4ka BP与现代.在第3阶段硅华活动早期,有一次钙华活动.     

Hydrochemical and isotope characteristics of spring water discharging from Qiushe Loess Section in Lingtai,northwestern China and their implication to groundwater recharge

The loess plateau in northwestern China with an area of 640 000km~2, which has developed the loess deposits with a thickness up to 200m in typical areas, is regarded as a huge carbon stock like the karst area in southwestern China, and plays an important role in regional(even global) carbon cycle. But the spring discharging from loess is poorly known compared with karst spring so far. The objective of this study is to ascertain the characteristics and origin of spring at Qiushe Village, Lingtai County, Gansu Province by hydro-chemical and isotopic methods. The results show that the springs including LGQ, HMQ, YYQ and CZQ are the depression spring and belong to the same shallow aquifer with the well water JZJ. There are not distinct seasonal/diurnal-scale variations on the hydro-chemical characteristics of the spring water(LGQ, HMQ, YYQ, CZQ) and groundwater(JZJ). The hydro-chemical type of groundwater is Ca·Mg-HCO_3. The D and O isotope ratios indicate that the precipitation is the main recharge source of groundwater in study area. And the results of tritium(TU) and Cl concentration suggest that the recharge cycle of groundwater may be more than 60 yrs. Our study shows that the water cycle in loess plateau including rainfall, infiltration, recharge and discharge exerts a continuous impact on carbon stock in loess, which should be paid more attention to in future research on the quantitative reconstruction of paleoclimate.     

泉域地下水数值模拟及泉流量动态变化预测

本文对位于岩溶地区的小南海泉泉域地下水进行了数值模拟和水平衡分析,全面分析了降雨、河、渠、库地表水系入渗对地下水动态变化的影响,模拟了泉流量动态变化与区域地下水关系.在此基础上,分析了不同气候条件和开采方案对泉流量的影响.模型计算结果表明,小南海泉流量多年平均相对变化率与降雨量多年平均变化率基本一致,减少泉域地下水开采量,特别是矿坑排水可有效地增加枯期泉流量.