地质学报2025，Vol.99Issue(5)：1711-1742,32.DOI:10.19762/j.cnki.dizhixuebao.2023079
冀北燕山隆起-华北断陷盆地地热流体地球化学特征及地热学意义
Hydrogeochemical evolution of geothermal fluids and its indications in the Yanshan uplift-North China fault basin,northern Hebei
摘要
Abstract
Geothermal fluids are a valuable source of hydrogeological and geochemical information,crucial for understanding deep circulation patterns,geothermal formation mechanisms,and guiding the development and utilization of geothermal resources.This study focuses on the Yanshan uplift-North China fault basin in northern Hebei Province.Based on regional geological and structural conditions,the geothermal system was zoned,and 91 water samples from geothermal wells and hot springs were collected.These samples were analyzed for their hydrochemical composition and isotopic characteristics to determine the recharge source,circulation path,temperature of the thermal reservoir,and the proportion of cold water mixed in during the upwelling of parent geothermal fluid in different geothermal geological zones.The results show that the study area can be divided into three geothermal geological zones:the Bashang Plateau mantle depression,the upper mantle ridge in the Yanshan platform fold belt,and the upper mantle uplift of the middle-northern North China rift depression basin.These zones were delineated based on geological structure and geothermal conditions.Correspondingly,the geologic models of geothermal systems in these zones are:a layered controlled system driven by deep depressions in volcanic sedimentary basins;a deep circulation and convection type associated with uplifted mountain faults,and a complex convection conduction type in intermountain sedimentary basins;and a complex convection and conduction hydrothermal type in buried mountains within sedimentary basins.From the Yanshan uplift to the North China fault basin,the hydrochemical evolution of geothermal fluids exhibits continuity at the macro-basin scale,with the deep hydrochemical field governed by groundwater runoff.Regionally,the hydrochemical types evolve from HCO3-Ca,HCO3-Na type to HCO3·SO4-Na,SO4-Na types,and then to Cl·SO4-Na,Cl-Na·Ca,and Cl-Na types,similar to large-scale basin groundwater systems.The temperature of the geothermal reservoir in the Bashang Plateau geothermal system ranges from 63.44 to 137.44℃,with fluid cycling depths of 1800 to 3770 m.The proportion of cold water mixed in during the upwelling of parent geothermal fluid is 51.0％to 92.2％.In the Yanshan platform fold belt,the geothermal reservoir temperature is 79.26 to 148.62℃,with thermal cycling depths of 2050 to 4817 m,and a cold water mixing proportion of 11.5％to 94.5％.The middle-northern North China rift depression basin exhibits a geothermal reservoir temperature of 71.41 to 144.49℃,thermal cycling depths of 2658.2 to 3444.6 m,and a cold water mixing proportion of 43.0％to 97.50％.The temperature of deep geothermal fluids in different zones,unaffected by cold shallow water mixing,is relatively consistent,ranging from 162 to 172℃.Areas where the depth of the earth's mantle changed steeply,forming mantle scarps,where geological structures vary significantly in the deep mantle,and at the intersection zones of primary and secondary faults with high terrestrial heat flow values,are identified as potential"dessert areas"for high-temperature geothermal resources in the Yanshan uplift-North China fault basin of northern Hebei Province.关键词
地热/水化学/同位素/燕山隆起/华北断陷盆地/冀北Key words
geothermal/hydrogeochemical/isotope/Yanshan uplift/North China fault basin/northern Hebei引用本文复制引用
孙厚云,马峰,朱喜,余鸣潇,陈自然,卫晓锋..冀北燕山隆起-华北断陷盆地地热流体地球化学特征及地热学意义[J].地质学报,2025,99(5):1711-1742,32.基金项目
本文为国家重点研发计划项目(编号2019YFB1504101)、中国地质科学院基本科研业务费项目(编号SK202328)和中国地质调查局项目(编号DD20230019)联合资助的成果. （编号2019YFB1504101）
