Establishing geothermometric constraints on the local geothermal gradients:Case study of the Eastern Cordillera Basin,Colombia

作     者：Carlos A.Barrera Carlos A.Vargas Jorge E.Cortes 

作者机构：Universidad Nacional de Colombia Carrera 45 No 26-85 Bogota Colombia Petromarkers Inc. 16850 Saturn Ln Houston TX 77058 United States 

出 版 物：《Geodesy and Geodynamics》 (大地测量与地球动力学（英文版）)

年 卷 期：2018年第9卷第4期

页      面：271-280页

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：provided by Colciencias grants 12455218627/784-2011 12335 6935004/0361-2013 FP44842-006-2016 and 50491-2016 

主　　题：Geothermometers Hydrochemistry Coal bed Formation waters Eastern Cordillera Basin 

摘      要：Geochemical analyses were performed on 170 coal bed-trapped groundwater samples from 97 underground mines located in the Eastern Cordillera Basin, Colombia. The waters analyzed in this paper are from exploited coal beds, located up to 0.73 km deep, which emerge along with the local fault *** hydrochemical facies were classified based on the concentration of major ions by inferring the equilibrium state and rock water source. The main hydrochemical facies presented in the groundwater study are SO_4-Ca-Mg, HCO_3-Ca, HCO_3-Ca-Mg, and SO_4-HCO_3 mixed waters. We used geothermometric equations to estimate the most probable temperature under in-situ conditions and the propagation of errors theory to test the results. The geothermal gradient in the study area is close to 30℃/km, which is consistent with measurements from oil wells within the study area. Principal Component Analysis was used to explain factors affecting formation water composition and hydrogeochemical evolution of aquifers.