Characteristics of hydrochemical compositions and stable carbon isotope of natural water in the Daggyia geothermal field, Tibet, China
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摘要: 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。Abstract: The objective of this work is to investigate the hydrochemical compositions of the geothermal water, lake water, river water, and ice- and snow-melt water as well as control factors of provenance in the Daggyia geothermal field of Tibet. The field surveys and sampling were conducted in August 2014. The main cations and anions of samples were measured using the ICP-OES and UV-visible spectrophotometer. The isotopic ratios of dissolved inorganic carbon (DIC) were analyzed using a gas stable isotope ratio mass spectrometer. The results show that the concentrations of total dissolved solids (TDS) range from 977.13 mg/L to 1 279.50 mg/L for geothermal water, and K+and Na+are the main cations, and HCO3-and Cl-are the main anions. The concentrations of TDS of the lake waters range from 77.81 mg/L to 810.94 mg/L, Ca2+, Na+, HCO3-(CO32-)andSO42-occupy the majority of ions. The hydrochemical types of both geothermal water and lake water are the type of bicarbonate-sodium. The ion concentrations of river and melt water are low, and the hydrochemical type is bicarbonate-calcium. The concentrations of DIC in geothermal water range from 9.2 mmol/L to 15.4 mmol/L, and that of δ13CDIC ranges from -9.09‰ to -0.95‰. The concentrations of DIC in lake water are 1.1 mmol/L to 9.7 mmol/L, the δ13CDIC values are -8.84‰ to -0.27‰. The Gibbs boomerang envelope of water samples indicates that the hydrochemical characteristics are mainly controlled by silicate rocks weathering in the area, and the major processes are the albite and potash feldspar weathering, while the hydrochemical compositions of geothermal water are also affected by dissolution of evaporation of salt rocks. The carbon sources of silicate weathering around the lakes are mainly soil carbon dioxide. Meanwhile the deep carbon dioxide input is the main source of silicate hydrolysis in hot spring areas.
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Key words:
- geothermal field /
- hydrochemistry /
- weathering /
- carbon isotope /
- Daggyia /
- Tibet
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[1] 佟伟,章铭陶,张知非,等.西藏地热[M].北京:科学出版社,1981. [2] 刘克纳,陈乐恬,刘全友.西藏南迦巴瓦峰地区天然水的化学特征[J].环境科学,1985,6(5):66-69. [3] Kawashima M, Nishiyama T. Salt concentration and chemical types of lake, river, snow, and hot spring waters from the Tibetan Plateau [J].Japanese Journal of Limnology, 1989, 50(2): 93-104. [4] Mitamura O, Seike Y, Kondo K, et al. First investigation of ultraoligotrophic alpine Lake Puma Yumco in the pre-Himalaya, China [J].Limnology, 2003, 4(3): 167-175. [5] Murakami T, Terai H, Yoshiyama Y, et al. The second investigation of Lake Puma Yum Colocated in the Southern Tibetan Plateau, China [J].Limnology, 2007, 8(3): 331-335. [6] Wang J B, Zhu L P, Wang Y, et al. Comparisons between the chemical compositions of lake water, inflowing river water, and the lake sediment in Nam Co, central Tibetan Plateau, China and their controlling mechanisms [J].Journal of Great Lakes Research, 2010, 36(4): 587-595. [7] 王君波,彭萍,马庆峰,等.西藏玛旁雍错和拉昂错水深、水质特征及现代沉积速率[J].湖泊科学,2013,25(4):609-616. [8] 王君波,鞠建廷,朱立平.季风期前后西藏纳木错湖水及入湖河流水化学特征变化[J].地理科学,2013,33(1):90-96. [9] 鞠建廷,朱立平,汪勇,等.藏南普莫雍错流域水体离子组成与空间分布及其环境意义[J].湖泊科学,2008,20(5):591-599. [10] 孙瑞,张雪芹,郑度.藏南羊卓雍错流域水化学区域差异及其成因[J].地理学报,2013,68(1):36-44. [11] 田原,余成群,雒昆利,等.西藏地区天然水的水化学性质和元素特征[J].地理学报,2014,69(7):969-982. [12] 赵平,金建,张海政.西藏羊八井地热田热水的化学组成[J].地质科学,1998,33(1):61-72. [13] 伍坤宇,沈立成,王香桂,等.西藏朗久地热田及其温泉水化学特征研究[J].中国岩溶,2011,30(1):1-8. [14] 李思亮,刘丛强,陶发祥,等.碳同位素和水化学在示踪贵阳地下水碳的生物地球化学循环及污染中的应用[J].地球化学,2004,33(2):165-170. [15] Amiotte S P, Aubert D, Probst J L, et al. δ13C pattern of dissolved inorganic carbon in a small granitic catchment: the Strengbach case study(Vosges mountains, France) [J].Chemical Geology, 1999, 159(1): 129-145. [16] Frondini F, Caliro S, Cardellini C, et al. Carbon dioxide degassing and thermal energy release in the Monte Amiata volcanic-geothermal area(Italy) [J].Applied Geochemistry, 2009, 24(5): 860-875. [17] 上官志冠,高松井.滇西实验场区温泉碳同位素地震地球化学特征[J].地震,1987,(6):25-35. [18] 肖琼,沈立成,杨雷,等.重庆北温泉地热水碳硫同位素特征研究[J].水文地质工程地质,2013,40(4):127-133. [19] 朱弟成,莫宣学,王立全,等.西藏冈底斯东部察隅高分异I型花岗岩的成因:锆石U-Pb年代学、地球化学和Sr-Nd-Hf同位素约束[J].中国科学D辑:地球科学,2009,39(7):833-848. [20] 河北省地质调查院区调所,石家庄经济学院.西藏自治区桑桑区幅区域地质调查报告(1:250000)[R]. 2003:72-154. [21] 佟伟,廖志杰,刘时彬,等.西藏温泉志[M].北京:科学出版社,2000. [22] 王鹏.藏南碰撞造山带典型水热区现代地球化学过程与小流域CO2源、汇关系研究[D].重庆:西南大学,2013. [23] Fytikas M, Kavouridis T, Leonis C, et al. Geochemical exploration of the three most significant geothermal areas of Lesbos Island, Greece [J].Geothermics, 1989, 18(3): 465-475. [24] Gibbs R J. Mechanisms controlling world water chemistry [J].Science, 1970, 170(3962): 1088-1090. [25] 李鹤,李军,刘小龙,等.青藏高原湖泊小流域水体离子组成特征及来源分析[J].环境科学,2015,36(2):430-437. [26] 曹敏,蒋勇军,蒲俊兵,等.重庆南山老龙洞地下河流域岩溶地下水DIC和δ13CDIC及其流域碳汇变化特征[J].中国岩溶,2012,31(2):145-153. [27] 蒲俊兵.重庆地区岩溶地下河水溶解无机碳及其稳定同位素特征[J].中国岩溶,2013,32(2):123-132. [28] 李甜甜,季宏兵,江用彬,等.赣江上游河流水化学的影响因素及DIC来源[J].地理学报,2007,62(7):764-775. [29] 张立成,董文江,王李平,等.长江水系河水的地球化学特征[J].地理学报,1992,47(3):220-232. [30] Reid N J, Hamilton S K. Controls on algal abundance un a eutrophic river with varying degrees of impoundment (Kalamazoo River, Michigan, USA) [J].Lake and Reservoir Management, 2007, 23(3): 219-230. [31] Barth J A C, Veizer J. Carbon cycle in St. Lawrence aquatic ecosystems at Cornwall (Ontario), Canada: Seasonal and spatial variations [J].Chemical Geology, 1999, 159(1): 107-128. [32] 伍坤宇.冈底斯—喜马拉雅造山系中部热泉地球化学特征及典型地热区CO2脱气通量研究[D].重庆:西南大学,2012. [33] Fiebig J, Chiodini G, Caliro S, et al. Chemical and isotopic equilibrium between CO2and CH4 in fumarolic gas discharges: Generation of CH4 in arc magmatic-hydrothermal systems [J].Geochemical et Cosmochimica Acta, 2004, 68(10): 2321-2334. [34] 沈立成,伍坤宇,肖琼,等.西藏地热异常区CO2脱气研究:以朗久和搭格架地热区为例[J].科学通报,2011,56(26):2198-2208. [35] France-Lanord C, Evans M, Hurtrez J E, et al. Annual dissolved fluxes from Central Nepal rivers: budget of chemical erosion in the Himalayas [J].Comptes Rendus Geoscience, 2003, 335(16): 1131-1140.
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