| 摘要: |
| 西藏地区位于欧亚板块与印度板块碰撞造山带，构造活动强烈，具有丰富的地热资源。本次研究在西藏阿里地区水热活动强烈的玛旁雍错地热田实地采集地表热泉样品进行水化学分析，依据地热水水化学特征，评估研究区热储平衡状态与热储温度，分析地热水在深部的水文地球化学过程，识别地热系统深部热源类型并阐明地热系统成因机制。通过此次研究表明：区内地热水主要为碱性Cl-Na型或HCO3-Cl-Na型水和酸性SO4-Na型水，地热水在深部已经与热储围岩达到完全平衡状态，通过地热温标计算热储温度在200℃左右；地热地表显示、热水水化学组分特征、热储温度类型等分析揭示玛旁雍错为岩浆热源型地热系统，地表不同类型地热水是深部母地热流体沿断裂向上运移过程中经不同水文地球化学过程形成。 |
| 关键词: 地热水 水文地球化学 岩浆热源 成因机制 玛旁雍错 |
| DOI：10.19826/j.cnki.1009-3850.2023.04009 |
| 相关附件： 20230107001-师红杰-附表.pdf |
| 投稿时间：2023-01-07修订日期：2023-04-11 |
| 基金项目:国家自然科学基金项目（41902257）；宁夏回族自治区重点研发计划项目（2022BEG03060）；自然资源部深部地热资源重点实验室开放基金项目（KLDGR2022G01）；宁夏回族自治区财政专项项目（NXCZ20220206） |
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| Geochemical characteristics and formation mechanisms of the geothermal waters from the Mapamyumco, Tibet |
| SHI Hongjie, LIU Mingliang, WEI Xing, CAO Yuanyuan, SHANG Jianbo |
(1. Hubei Key Laboratory of Petroleum Geochemistry and Environment & College of Resources and Environment, Yangtze University, Wuhan 430100, China;
2. Geophysical and Geochemical Exploration Institute of Ningxia Hui Autonomous Region, Yinchuan 750001, China) |
| Abstract: |
| Tibet is located at the Indian-Eurasia collision orogenic belt, where the tectonic activity is intense, resulting in abundant geothermal resources. In this study, the hot spring samples from the Mapamyumco geothermal field situated at the Ngari Prefecture of Tibet with strong geothermal activity were collected for hydrochemical analysis. Based on the hydrochemical characteristics of the geothermal water, the equilibrium state and temperature of the reservoir was evaluated; the hydrogeochemical processes of deep geothermal fluid was analyzed; and the heat source type of the geothermal system was identified. These results are contributed to clarify its genesis mechanism. This study shows that: the geothermal water in the area are mainly alkaline Cl-Na type or HCO3-Cl-Na type and acidic SO4-Na type water; the geothermal water has reached a complete equilibrium state with the thermal reservoir rocks at depth, and the thermal reservoir temperature is about 200℃ based on geochemical geothermometer calculation; surface geothermal manifestations, hydrochemical characteristics of geothermal water, and the reservoir temperatures reveal that Mapamyumco geothermal field is a magmatic geothermal system, and different types of geothermal water are formed by different hydrogeochemical processes during the upward transport of deep parent geothermal fluid along the fault. |
| Key words: geothermal water hydrogeochemistry magmatic heat source formation mechanism Mapamyumco |
