山西地震带北段断裂带土壤气体地球化学特征

发布时间：2018-03-04 07:20

本文选题：地球化学　切入点：活动断裂　出处：《中国地震局地震预测研究所》2015年硕士论文　论文类型：学位论文

【摘要】：山西地震带北段北与张家口—渤海湾地震带(张渤带)交汇,该区构造活动强烈,发生强震的危险性较大。活动断裂带的土壤气体地球化学测量在活动断裂危险性评价方面起着重要作用。张渤带以及山西地震带已有的土壤气地球化学调查主要集中在张渤带的中段以及东南段。在研究区域内还缺乏土壤气体地球化学调查。本文的目的是研究山西地震带北段断裂带的土壤气地球化学特征及其构造意义。其结果对进一步在研究区域开展地震流体地球化学连续监测和地震流体前兆异常判定方面有重要的作用。于2014年5月至6月间对山西地震北段的蔚县广灵断裂、六棱山北麓断裂、阳原盆地北缘断裂、阳高天镇断裂、口泉断裂、大同火山许堡—阁老庄断裂以及怀安盆地北缘断裂进行了土壤气中CO2、Rn、Hg、H2和He浓度,CO2、Rn和Hg通量以及1m深处土壤CO2、Rn通量的测量,共计12个土壤气测量区域,120个浓度测点,36个CO2、Rn和Hg通量测点以及12个1m深处的CO2、Rn通量测点。Rn浓度利用RTM2200型测氡仪测定;采用Agilent 3000型便携式气相色谱仪对土壤气体CO2、He和H2进行测量;Hg浓度利用RA-915+型塞曼效应(Zeeman effect)测汞仪进行测量。分别使用RAD7测氡仪、GXH-3010E型便携式红外线CO2分析仪和RA-915+型塞曼效应(Zeeman effect)测汞仪对Rn、CO2和Hg通量进行测量。测量结果显示:研究区域土壤气体Rn、CO2浓度空间分布差异大,H2、He、Hg浓度空间分布差异较小。土壤气中CO2、Rn、Hg、H2、He浓度平均值变化范围分别为:0.22~0.79%,6.64~10.72 k Bq/m3,8~18ng/m3,1.02~1.98×10-6,4.89~5.76×10-6。土壤气中CO2、Rn、Hg、H2、He浓度空间分布曲线在断层面一侧出现单峰或多峰形态。研究区域土壤气中CO2、Rn、Hg近地表通量以及1m深处土壤CO2、Rn通量的空间分布差异大,土壤气CO2、Rn、Hg近地表通量平均值变化范围为:1.57~69.33g/m2d,17.33~85.07m Bqm2s以及1.07~31.04 ng/m2h。1m深处土壤CO2、Rn通量的的变化范围分别是:0.01~59.33g/m2d,6.24~373.87 m Bq/m2s。研究区土壤气CO2、Rn的脱气较为强烈。这几条断裂土壤气CO2以及Hg脱气量的变化范围为:24.05~288.68 t/d和0.13~4.44 g/d。各土壤气测区土壤气CO2、Rn通量值与土壤气CO2、Rn浓度平均值之间存在正相关关系。测区土壤气CO2、Rn通量值随深度增加而增加。研究区域内同一断裂带土壤气不同组分的空间变化特征主要与断裂活动有关,不同断裂带土壤气不同组分空间变化特征受断裂活动性、土壤类型、岩石类型等因素共同影响。断裂带土壤气不同组分的空间变化特征能够较好地反映断层活动性。
[Abstract]:The northern section of the Shanxi seismic belt intersects with the Zhangjiakou-Bohai Bay seismic belt (Zhangbo belt), and there is strong tectonic activity in the area. Geochemical survey of soil gas in active fault zone plays an important role in risk assessment of active fault. Geochemical investigation of soil Gas in Zhangbo Belt and Shanxi Seismic Belt. In this paper, the geochemical characteristics of soil gas and its tectonic significance in the northern fault zone of Shanxi seismic belt are studied. The results play an important role in the continuous geochemical monitoring of seismic fluids and the determination of precursory anomalies of seismic fluids in the study area. From May 2014 to June, the Weixian Guangling fault in the northern segment of the Shanxi earthquake was studied. Lulingshan North Piedmont Fault, Yangyuan Basin North margin Fault, Yanggao Tianzhen Fault, Kou Quan Fault, The fluxes of CO _ 2C _ 2R _ 2H _ 2H _ 2H _ 2H _ 2H _ 2 and he concentration of CO _ 2O _ 2N _ n and Hg in the soil and the fluxes of soil CO _ 2C _ 2R _ n in 1m depth were measured in the Xubo-Goraozhuang fault of Datong Volcano and the fault in the northern margin of Huai'an Basin. A total of 12 soil gas measuring areas, 120 concentration measuring points, 36 CO _ 2C _ 2R _ n and Hg flux measuring points and 12 ~ 1m depth CO _ 2N ~ (2 +) R _ n flux measuring sites. Rn concentrations were measured by RTM2200 radon meter. Agilent 3000 portable gas chromatograph was used to measure the concentration of CO _ 2H _ 2He and H _ 2 in soil using RA-915 Zeeman effectmeter. RAD7 radon detector GXH-3010E portable infrared CO2 analyzer and RA-915 plug were used respectively. The experimental results show that the spatial distribution difference of soil gas Rnn CO 2 concentration is small. The variation range of mean value of CO 2H 2 Hnn CO 2 he concentration in soil gas is very small in the study region, and the variation range of carbon dioxide concentration in soil gas is lower than that in the field of Hnn ~ (2) H _ (2) H _ (2) H _ (2) H _ (2) H _ (2) H _ (2) he concentration in soil gas. The spatial distribution curves of CO _ 2 ~ (2 +) Rn ~ (2) H _ (2) H _ (2) H ~ (2 +) H _ (2) H _ (2) O ~ (2 +) H _ (2) H _ (2) H _ (2) H _ (2) H _ (2) H _ (2) he concentration curve of soil gas in the study area showed a single peak or multiple peaks on one side of the fault plane. The spatial distribution of soil CO _ 2N ~ (2 +) fluxes near the surface and in the depth of 1m in the soil atmosphere showed great difference in the spatial distribution of the surface fluxes of CO _ (2) N ~ (3) and the soil CO _ 2Rn fluxes in the depth of 1m m ~ m. The mean variation range of soil CO _ 2N ~ (2 +) flux near the surface is: 1.57 ~ 69.33 g / m ~ (-2) d ~ (-1) 17.33 ~ 85.07 m Bqm2s and 1.077 ~ 31.04 ng/m2h.1m, respectively. The variation range of soil CO _ 2N flux is: 0.01 ~ 59.33 g / m ~ (2) d ~ (-1) 6.24373.373.87 m ~ (2) Q / m ~ (2) s. The degassing of soil gas CO _ 2C _ (2) rn in the study area is very strong. The variation range of gas volume is: 24.05 / 288.68 t / d and 0.13 ~ 4.44 g / d. There is a positive correlation between soil CO _ 2C _ 2C _ 2N _ n flux and the average value of soil gas CO _ 2C _ 2R _ n concentration in each soil gas measuring area. The soil gas CO _ 2N _ n flux increases with the increase of depth. The spatial variation characteristics of different components of soil gas in a fault zone are mainly related to fault activity. The spatial variation characteristics of different components of soil gas in different fault zones are affected by factors such as fault activity, soil type and rock type, etc. The spatial variation characteristics of different components of soil gas in fault zone can well reflect fault activity.
【学位授予单位】：中国地震局地震预测研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P315.7

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