甘肃武威西营地区存在优质干热岩资源的可能性探讨  

DISCUSSION ON THE POSSIBILITY OF HIGH QUALITY DRY HOT ROCK RESOURCES IN XIYING AREA OF WUWEI DISTRICT, GANSU PROVICE

作　　者：鲁有朋 王玉玺 马涛 包国志 李腾飞 杨春霞 LU You-peng;WANG Yu-xi;MA Tao;BAO Guo-zhi;LI Teng-fei;YANG Chun-xia(The Third Institute of Geology and Mineral Exploration,Gansu Provincial Bureau of Geology and Mineral Exploration and Development,Lanzhou 730050,China)

机构地区：[1]甘肃省地矿局第三地勘院,甘肃兰州730050

出　　处：《甘肃地质》2021年第2期78-83,共6页Gansu Geology

摘　　要：研究区位于甘肃省武威市凉州区西北部,中酸性岩体发育,活动断裂密集,温泉密布,地热钻井揭露温度高,80.23 m钻孔实测孔底温度可达59℃;地温梯度高达8.5℃/100 m,是正常地温梯度2~3倍,地热增温随深度增大而升高;航磁△T异常等值线图经航空磁力测量图解译,研究区南部有NW—SE向有磁异常,推测区内航磁△T异常由隐伏花岗岩体引起;依据岩石放射性分析,区内规模较大的北大坂花岗岩体中含有半衰期长、含量高的铀(U)、钍(Th)、钾(K)等放射性元素,是构成干热岩成藏的稳态热源;侏罗系、白垩系泥岩、砂砾岩等对干热岩成藏起到聚热保温的作用,是构成干热岩成藏的良好盖层。通过对该区地质、水文、地球物理资料的研究认为,武威市西营地区存在潜力较大的优质的高热流酸性岩体型干热岩资源,建议在该区开展干热岩资源的专项调查研究工作,建立干热岩资源靶区,为今后的开发利用奠定基础。The research area is located in the northwest of Liangzhou District, Gansu Province, where the intermediate-acid rock body is well developed, the active faults are concentrated, the hot springs are distributed,the temperature of geothermal drilling is high, the temperature at the bottom of 80. 23 m borehole is 59℃, and the geothermal gradient is 8. 5℃/100 M, the results show that there is a NW-SE magnetic anomaly in the southern part of the study area, which is 2 ~ 3 times of the normal geothermal gradient, and the geothermal temperature increases with the increase of depth, it is inferred that the aeromagnetic △ t anomaly in the area is caused by the concealed granite body, and based on the analysis of rock radioactivity, the large-scale Baidaban granite body in the area contains radioactive elements such as uranium(U), thorium(Th), potassium(k) with long half-life and high content, etc., the stable heat source that forms the reservoir of the dry-hot Rock;the Jurassic, Cretaceous Mudstone, glutenite and so on play the role of heat accumulation and heat preservation for the formation of the dry-hot rock reservoir and constitute a good cover for the formation of the dry-hot rock reservoir,there are high-quality and high-potential dry hot ROCK RESOURCES OF HIGH-HEAT-FLOW ACIDIC ROCK body in Xiying area of Wuwei city, which is the first target area for seeking dry hot rock resources in Gansu Province, the development and utilization of the dry-hot rocks in Gansu Province were opened up.

关 键 词：西营地区 干热岩 热流值 磁异常 花岗岩 放射性热源 甘肃武威 

分 类 号：P314.2[天文地球—固体地球物理学]