煤田地质与勘探2025，Vol.53Issue(6)：48-57,10.DOI:10.12363/issn.1001-1986.25.01.0010
兰州盆地浅部地热水地球化学特征及含氦流体形成机理
Geochemical nature of the geothermal water from Lanzhou Basin:Implications for the genesis of shallow helium-bearing fluids
摘要
Abstract
[Objective and Methods]Investigations on the geochemical nature of geothermal water are vital to the com-prehension of the origin of helium-rich fluids in shallow basins.To address this issue,this paper reports the results of the chemical analysis,H-O isotopes and 14C ages from geothermal water and soluble gas components from the well BY-1 in Lanzhou Basin,northeastern margin of Qinghai Tibet Plateau.Chemical analysis of geothermal water samples reveals that the chemical type of geothermal water is NaCl.The show δD value of-78‰,high δ18O value(-8.7‰),low 3H value(＜0.4TU),and old 14C age(20.50±0.92ka).The geothermal water has undergone evaporation-concentration and water-rock interactions,which originated from ancient atmospheric precipitation.Component analysis from 10 water-dissolved gas samples reveals an average helium concentration of 0.44％.The concentration of He meets the standard for helium-rich gas fields.Compositions of the dissolved gas and the geochemical nature of the groundwater jointly suggest that the associated helium in the geothermal water from this well is a product of the radioactive decay of Th-U elements in the basement rocks of the basin.Comprehensive analysis indicates that the upward migration and accumulation of an-cient helium-bearing water from the basement into shallow geothermal reservoirs along fault zones under the back-ground of tectonic uplift is the key process for the enrichment of associated helium in geothermal water in the Lanzhou Basin.关键词
氦气/地热水/地球化学特征/新近系杨稍组/兰州盆地/青藏高原东北缘Key words
helium/geothermal water/geochemistry/Neogene Yangshao Formation/Lanzhou Basin/northeastern mar-gin of Qinghai Tibet Plateau分类
地质学引用本文复制引用
唐建洲,王双明,张志诚,李可,李长鹏..兰州盆地浅部地热水地球化学特征及含氦流体形成机理[J].煤田地质与勘探,2025,53(6):48-57,10.基金项目
陕西省教育厅科学研究计划项目(24JK0547) （24JK0547）
陕西省博士后基金项目(2024BSHSDZZ191) （2024BSHSDZZ191）
陕西省油气成藏地质学重点实验室开放基金项目(PAG-202407) （PAG-202407）
