北山地区扎格高脑盆地CEMP采集试验研究

Acquisition test for CEMP in Zhagegaonao Basin of Beishan area

为确定北山地区电法野外采集参数,有效合理地开展连续电磁剖面法(Continuous Electromagnetic Profiling,CEMP)勘探,以扎格高脑盆地为例,针对野外资料采集的主要因素,制定了采集参数的试验研究工作,通过视电阻率曲线成图对比分析了各项参数所对应的数据采集结果,确定了电极距长度和采集时间。综合研究认为:研究区布极电极距长度宜采用100 m,个别困难地区可适当缩短电极距,但至少需大于70 m;野外有效采集时间选择12 h效果较好,特殊情况下不低于8 h,干扰区需适当延长采集时间;针对接地电阻、刮风干扰等影响野外数据采集质量的不同情况,总结分析了质量控制对策与改善措施。实测剖面解释结果表明,CEMP能较好地揭示研究区主要地层展布情况,反映研究区构造特征。该研究结果可为北山地区中生代盆地群CEMP勘探部署提供依据。

In order to determine the field acquisition parameters of electrical collection in Beishan area,and carry out CEMP exploration effectively and reasonably,the authors took Zhagegaonao Basin as an example and set up series of experimental research work on collecting parameters according to different factors affecting field data collection.The data acquisition results for each parameter were analyzed through comparison of the apparent resistivity curves,and the appropriate electrode spacing and acquisition time were also determined.According to the comprehensive research,the electrode spacing in the study area should be 100 m,and it can be shortened appropriately in some harsh areas,with the minimal value of 70 m.The effective acquisition time in the field is 12 hours,and it should not be less than 8 hours in some special cases.The acquisition time should be extended appropriately in interference areas.The authors also summarized and analyzed the quality control countermeasures and improvement measures in different situations that affect the quality of field data collection,such as grounding resistance and wind interference.The field section interpretation shows that CEMP can reveal the main strata distribution and reflect the structural characteristics of the study area.The results of this paper can provide a basis for CEMP exploration and deployment of Mesozoic basins in Beishan area.