滇西大理地区部分温泉溶解CO2及碳同位素组成特征研究

(云南省地震局,云南 昆明 650224)

温泉; 水化学常量离子; CO2和碳同位素组成; 地震; 大理

Characteristics of the Carbon Isotope of the Dissolved CO2 in Hot Springs in Dali Region,West Yunnan Province
ZHANG Xiang,FU Hong,LUO Ruijie,LI Bo,ZI Chengzhu

(Yunnan Earthquake Agency,Kunming 650224,Yunnan,China)

hot spring; hydrochemical ions; CO2 and carbon isotope; earthquake; Dali region

备注

温泉溶解CO2的来源成因研究,有利于判断与甄别研究区温泉溶解CO2异常信息。对2016年10月至2017年7月大理地区3个温泉的水化学常量离子和δ13CHCO3-进行了10次重复取样观测,对3个温泉的水文地球化学及CO2来源进行分析。结果表明:3个温泉均属于HCO3?SO4-Na型水,地下水补给都来自于大气降水,CO2主要来自于深部的地幔成因和变质成因的CO2; 2017年漾濞MS5.1地震发生前,3个温泉的δ13CHCO3-值与HCO3-正相关关系发生改变,表明温泉δ13CHCO3-值与地震有一定的相关性。
Finding the source of the dissolved CO2 in hot springs in the study area will facilitate judging and assessing the anomalous information about the dissolved CO2.From October 2016 to July 2017,10 repeated sampling observations were made on hydrochemical ions and δ13CHCO3- in three hot springs:Xiaguan,Eryuan and Midu in Dali region,West Yunnan Province.The results showed that the three hot springs' water belonged to HCO3?SO4-Na type.The analysis of Hydrogen-oxygen isotope indicated that the groundwater recharge of the three hot springs was derived from atmospheric precipitation.The analysis of carbon isotope showed that the CO2 in the three hot springs was mainly derived from the deep mantle and metamorphism.Before the Yangbi 5.1-magnitude earthquake in 2007,which was located within 100 km from these three hot springs,the positive correlation between the background values of δ13CHCO3- and HCO3 - in the three hot springs were observed broken,which indicated that the δ13CHCO3- value had a certain correlation with the Yangbi earthquake.