凌源-宁城地区位于燕辽沉降带东部（如图1），在中新元古界时期沉降缓慢、地层发育齐全、厚度巨大，且变质作用较小，具有较好的生烃潜力和油气勘探价值。

The Yanshan thrust belt (YTB) is located at the northern edge of the North China plate. Because of the intense thicking and subsequent delamination of the lithosphere in north China, geologists have been focused on the Late Mesozoic deformation in the Yanshan belt. The Yanshan belt has been regarded as part of a stable craton from the Proterozoic to the early Mesozoic. In this paper, the authors present that the Yanshan area was deformed during the early Mesozoic. This deformation could be related to ocean basin closure along the northern margin of North China, or related to the collision between the north China and Yangtze Plates along the Qinling-Dabie ultrahigh pressure belt. Three stages of early Mesozoic deformation are identified in the eastern Yanshan at Lingyuan County. The first stage is characterized by westward thrusting (D1), the second stage comprises a top-to-east thrust system (D2), and the third stage comprises extensional gravity-induced collapse and landsliding (D3). The timing of these evens is constrained by both the crosscutting relationships of faults and the isotopic dating of volcanic rocks and gravels. The D1 and D2 events took place in the Late Triassic and Early Jurassic, whereas D3 event occurred at the end of the Middle Jurassic. The Dengzhangzi formation was deposited during the D1-D2 period and recorded a rapid uplift, erosion, and deposition sequence. These early Mesozoic contractional deformations in the YTB were probably related to the closure of ancient Asian ocean and ancient Qinling ocean. The later crustal extension was caused by gravitational collapse of the eastern China plateau during early Mesozoic.

The Late Paleozoic collision between the North China continental block and the Altaid arc terranes of Mongolia represents one of the earliest and most fundamental tectonic events in the ongoing construction of Asia. New detrital zircon provenance data from Carboniferous-Permian nonmarine strata on the northern margin of North China imply that the northern margin of the North China block constituted a continental margin arc prior to this collision (~400-275 Ma) and that collision took place via south-directed subduction beneath North China.

he China-Mongolia border region contains many late Mesozoic extensional basins that together constitute a regionally extensive basin system.Individual basins within the system are internal ly composed of a family of sub-basins filled with relatively thin sedimentary piles mostly less than 5 km in thickness.There are two types of sub-basins within the basins,failed and combined,respectively. The failed sub-basins are those that failed to continue developing with time.In contrast,the combined ones are those that succeeded in growing by coalescing adjacent previously isolated subbasins. Thus,a combined sub-basin is bounded by a linked through-going normal fault that usually displays a corrugated trace on map view and a shallower dip on cross-section.Along-strike existence of discrete depocenters and alternation of sedimentary wedges of different types validate the linkage origin of combined sub-basins.Localized high-strain extension resulted in large-amount displacement on linked faults,but contemporaneously brought about the cessation of some isolated fault segments and the formation of corresponding failed sub-basins in intervening areas between active linked faults.Some combined sub-basins might have evolved into supradetachment basins through time,concurrent with rapid denudation of footwall rocks and formation of metamorphic core complexes in places.A tectonic scenario of the broad basin system can be envisioned as an evolution from early-stage distributed isolated sub-basins to late-stage focused combined or/and supradetachment sub-basins bounded by linked faults,accompanied by synchronous cessation of some early-formed sub-basins. Initiation of the late Mesozoic extension is believed to result from gravitational collapse of the crust that had been overthickened shortly prior to the extension.Compression,arising from collision of Siberia and the amalgamated North China-Mongolia block along the Mongol-Okhotsk suture in the time interval from the Middle to Late Jurassic,led to significant shortening and thickening over a broad area and subsequent extensional collapse.Pre-and svn-extensional voluminous magmatism must have considerably reduced the viscosity of the overthickened crust,thereby not only facilitating the gravitational collapse but enabling the lower-middle crust to flow as well.Flow of a thicker crustal layer is assumed to have occurred coevally with upper-crustal stretching so as to diminish the potential contrast of crustal thickness by repositioning materials from less extended to highly extending regions.Lateral middle-and lower-crustal flow and its resultant upward push upon the upper crust provide a satisfying explanation for a number of unusual phenomena,such as supracrustal activity of the extension,absence or negligibleness ofpostrift subsidence of the basin system,less reduction of crustal thickness after extension,and non-compression-induced basin inversion,all of which have been paradoxical in the previous study of the late Mesozoic basin tectonics in the China-Mongolia border region.

将广域电磁法应用于湘西龙山地区的碳质页岩探测，揭示了该区碳质页岩的含碳量较高，相对上、下地层显示为低阻的特征。采用自主研发的“重磁电三维反演成像解释一体化系统”进行广域电磁法数据处理，获得了地下电性体真实的电阻率特征，基本查明龙山地区碳质泥页岩层位的电性分布规律。表明广域电磁法是获取碳质页岩分布范围和埋深的有效探测手段。

采用广域电磁法在南华北盆地长山隆起地区进行探测,基本查明了工作区内基底起伏、埋藏深度和地层在空间上的主要分布,揭示了低阻区域的埋藏深度和厚度,从而确定了寻找页岩层的有利地段,解释结果得到钻孔验证,取得了较好的地质效果。勘探成果为确定页岩气开采＂靶区＂和＂甜点区＂提供了极为有用的地质地球物理信息,同时验证了广域电磁法探测页岩气赋存地层的有效性。

使用广域电磁法勘查了江苏省仪征市捺山地区的深层地热资源,查明了工区的第一热水储层和第二热水储层,钻遇储层出水量大、温度高。勘查结果显示广域电磁法是一种高效的深层地热能资源地球物理勘查方法,具有深度大、分辨率高、野外数据采集快等优点,勘查深度超过1 500 m,是深层地热能资源勘查主要的地球物理勘查方法。

根据水平电流场源和垂直磁场源在半均匀空间地面的电磁场解析表达式,定义了广域视电阻率,建立1种新的频率域测深方法即广域电磁测深法。研究结果表明:采用广域电磁测深法可以在过渡带进行测量,即以较小的收发距探测到较大的深度;广域电磁法包括E-Ex广域电磁测深和E-Ez广域电磁测深等方式,每种方式各有其特点,而且都只测量1种物理量;广域电磁法与2n序列伪随机电法相结合还可以发展成2n序列伪随机信号-广域电磁法,不但探测深度大,而且效率高,广域电磁法可用于寻找火山岩油气藏、深部金属矿和工程电法勘探。

在我国南方地区,复杂的地形和地下构造限制了常规地震勘探方法在页岩气勘探中的使用,如何充分、合理地发挥非地震勘探方法的技术优势,是页岩气勘探中必须面对的问题。为此在湖南保靖地区使用广域电磁法,以龙马溪组和牛蹄塘组为目的层,进行页岩气勘探,并对勘探成果进行解释,确认了该地区页岩气目的层具有低电阻的特征,基本查明了该地区页岩气主要目的层的分布规律。勘探结果表明,龙马溪组和牛蹄塘组具有使用电磁法勘探的电性基础;广域电磁法作为一种非地震的电磁勘探方法,具有在复杂地形和地下构造地区进行页岩气勘探的能力。该结果为电磁勘探方法在页岩气勘探中的应用提供了重要依据,促进了我国南方页岩气勘探方法技术的完善。