Electrical resistivity imaging of hydrologic flow through surface coal mine valley fills with comparison to other landforms

Surface coal mining has altered land cover, near‐surface geologic structure, and hydrologic processes of large areas in central Appalachia, USA. These alterations are associated with changes in water quality such as elevated total‐dissolved solids, which is usually measured via its surrogate, specific conductance (SC). The SC of valley fill effluent streams is a function of fill construction methods, materials, and age; yet hydrologic studies that relate these variables to water quality are sparse due to the difficulty of conducting traditional hydrologic studies in mined landscapes. We used electrical resistivity imaging (ERI) to visualize the subsurface geologic structure and hydrologic flow paths within a valley fill. ERI is a noninvasive geophysical technique that maps spatiotemporal changes in resistivity of the subsurface. We paired ERI with artificial rainfall experiments to track infiltrated water as it moved through the valley fill. Results indicate that ERI can be used to identify subsurface geologic structure and track advancing wetting fronts or preferential flow paths. Our results suggest that the upper portion of the fill contains significant fines, whereas the deeper profile is primarily large rocks and void spaces. Water tended to pond on the surface of compacted areas until it reached preferential flow paths, where it appeared to infiltrate quickly down to >15 m depth in 75 min. ERI applications can improve understanding of how fill construction techniques influence subsurface water movement, and in turn may aid in the development of valley fill construction methods to reduce water quality effects.     

内蒙古老国营子金铜矿床地质-地球物理勘查与研究

内蒙古老国营子金铜矿床是近年来利用地质与地球物理相互结合手段新发现的一个矿床。本次研究利用基于电磁原理的地球物理手段进行了找矿测试,结果表明:甚低频(VLF)地球物理扫面发现了近EW向和NW向的高阻带,分别对应了两条相应的矿化蚀变带。音频大地电磁法(EH4)测深影像显示矿化蚀变带表现为高阻异常带,与VLF的测量结果相一致。激电(IP)中梯测量显示矿化蚀变带具有高阻、高充电率和高金属因子异常特征。结合具体的地质特征,在老国营子金铜矿区综合运用这三种地球物理方法,取得了较好的找矿效果。     

Research on Formation Mechanisms of Hot Dry Rock Resources in China

As an important geothermal resource, hot dry rock(HDR) reserves have been studied in many countries. HDR resources in China have huge capacity and have become one of the most important resources for the potential replacement of fossil fuels. However, HDR resources are difficult to develop and utilise. Technologies for use with HDR, such as high–temperature drilling, reservoir characterisation, reservoir fracturing, microseismic monitoring and high–temperature power stations, originate from the field of oil and drilling. Addressing how to take advantage of these developed technologies is a key factor in the development of HDR reserves. Based on the thermal crustal structure in China, HDR resources can be divided into four types: high radioactive heat production, sedimentary basin, modern volcano and the inner–plate active tectonic belt. The prospective regions of HDR resources are located in South Tibet, West Yunnan, the southeast coast of China, Bohai Rim, Songliao Basin and Guanzhong Basin. The related essential technologies are relatively mature, and the prospect of HDR power generation is promising. Therefore, analysing the formation mechanisms of HDR resources and promoting the transformation of technological achievements, large–scale development and the utilisation of HDR resources can be achieved in China.     

综合物化探方法在铁及多金属矿勘查中的应用——以包恩亨地区为例

研究区位于内蒙古包恩亨一带,地表覆盖较厚,找矿标志不明显,综合物化探方法对发现和圈定铁及多金属异常起到了重要作用,取得了显著成果。总结异常区的地质、地球物理和地球化学特征,对处于同一成矿远景区的其他地段寻找该类型矿床,具有十分重要的意义,为寻找隐伏矿床提供了依据。     

遥感在宁夏贺兰山东北段1∶50000区域地质调查中的应用研究

以SPOT5及ETM+影像为基础数据,采用3D GIS遥感技术,通过对研究区岩性地层、线性构造、环形构造等地质体的遥感影像特征系统总结,结合野外调查,建立岩性地层及构造解译标志,对宁夏贺兰山东北段1∶50 000区域地质调查工作区进行遥感地质解译。解译结果表明:研究区西部多被贺兰山岩群和古元古代花岗岩覆盖,中部及东南部大部分为第四系和新近系地层;东部石峡谷、黑龙贵及老石旦镇地区,主要出露地层有奥陶系及寒武系;研究区构造发育,主要分布在西部贺兰山基岩区,共解译出线性构造113条,以NEE向和近SN向线性构造最为发育,线性构造相互切割,形成"块状"特征;环形构造33个,在区域上总体呈SN向条带状分布;褶皱4处,均为紧密型褶皱组合;不整合界线1条;总体呈"西部构造发育,局部呈块状,东西差异明显"的特点。实践表明,在1∶50 000区域地质调查中应用遥感和GIS相结合的方法,对提高区域地层构造认识以及遥感解译精度有较大帮助,能有效提高填图质量和工作效率,在区域地质调查工作中有良好的应用价值。     

AS350B3型直升机在中高山航空物探测量中的优势

中高山地区作业的航空地球物理勘探飞行器需要有高原适航性。通过对比空中国王350ER在起降条件、最大升限、最大续航能力及高原机动能力等特点,提出了在中高山地区的低高度、大比例尺的航空地球物理勘探飞行器的选型原则及飞行方法。通过甘肃某测区的实际测量飞行验证了该原则和方法的可行性。分析结果显示,AS350B3型直升机在中高山地区作业时表现出的实际飞行性能满足在该类型区域低高度、大比例尺的航空地球物理勘探的要求。     

钻探-物探测井技术在覆盖区填图中的应用研究

钻探作为获取深部地质信息的最直接手段,可查明第四纪地层序列,确定基岩顶面埋深与起伏、验证推测模型、研究地质构造、圈定地质体间的重要接触关系,服务于覆盖区填图。物探测井是一种科学有效的井内探测手段,利用特定的岩性或岩性组合对应着特定的测井参数组合的特点,利用测井参数组合可识别地层的岩性、确定地层的深度与厚度,可进行地层划分对比等。钻探-物探测井技术的综合利用,将提高覆盖区勘探效率,降低勘探成本,为下一步开展的覆盖区填图工作提供技术方法支撑。     

岩溶塌陷灾害的岩溶地下水气压力监测技术及应用

文章系统、全面地介绍了岩溶地下水气压力监测技术及其应用成果。该技术在监测成孔、孔口的密封及监测频率等方面创新性地提出了相关的工艺方法,能真实、及时且充分地反映出岩溶管道裂隙系统中的地下水气压力变化特点,可为岩溶塌陷的机理研究、监测和预警提供科学依据。岩溶地下水气压力监测技术工艺简单、操作方便、成本低廉,经过20多年的改进,已成功应用于全国11个典型岩溶塌陷区,服务于高铁、水源地、油气管线、市政建设等潜在岩溶塌陷风险性评价、安全降深、监测预警等方面,取得了很好的效果。      

西秦岭温泉—中川一带金属矿床的成矿规律及找矿预测

西秦岭温泉—中川一带实施的1:5万矿产地质调查项目,共圈定1:5万局部高磁异常33处,1:5万地球化学综合异常11处,发现矿点2处,矿化点5处,矿种有金、钼、铁、铜、铷等。通过分析研究区成矿地质条件、1:5万地球物理和地球化学综合异常特征、矿(化)点特征及分布规律等,阐明了该区成矿时空分布规律和矿产共生组合规律,划分成矿远景区9处,提交找矿靶区6处。对其中2处找矿靶区进行槽探验证的结果为: 关子镇幅玉杨观找矿靶区圈定了4条含铷矿化伟晶岩脉和多处铁矿化破碎蚀变带,具有形成伟晶岩型铷矿的潜力; 礼县幅李坝金矿床南侧百叶沟—河西沟找矿靶区圈定了14条蚀变破碎带,在矿化蚀变带内圈定了11条金矿(化)体,具有形成构造蚀变岩(微细粒浸染状)型金矿床的潜力。     

综合物探方法在广西妙皇隐伏多金属矿勘查中的应用

妙皇多金属矿区位于来宾凹陷东缘与大瑶山隆起西侧交接部位,广西大瑶山及其西侧铅锌成矿带中部成矿条件优越,历年来开展过多种研究和找矿方法,但找矿效果不佳。通过研究妙皇铜铅锌银矿区的地质条件和成矿背景,运用综合物探方法,对区内部分地质问题及矿产特征进行了推断和预测。2012年,依据地质物探综合成果布置了ZK22701号验证孔,取得了突破性的进展。同时,依据物探成果推测了矿区成矿机理和成矿模式,在找矿方向和找矿潜力方面进行了分析探讨,对中深部找矿具有很好的指导意义。