The Study About Transien Electromagnetic Method In Metallic Ore Exploration

With the exploration and development of mineral resources, the shallow andterrain conditions mines have been developed using, exploration of deep complexareas imminent, traditional geophysical methods can not fully meet the current needs,new theories and new technology development is imperative.Time domain electromagnetic method or called transient electromagnetic methodis the fastest growing in recent years, an artificial source of electromagnetic detectionmethod, it’s probing depth, the low resistivity body responsive, observations arepurely secondary field, can effectively identify deep complexity of the ore body in theregion, and high efficiency, low labor intensity of the field. Therefore, this study wasconducted through the application of the theory on its mineral combined with fieldexamples, in order to have guiding significance in the after actual work.First describes the article’s topic basis and TEM development at home andabroad, brief summary of the main contents of this paper, and summarize principlestransient electromagnetic exploration and field devices used, analysis of its strengthsand limitations, provides a reference after the field work while on the selected device.Then gives the transient electromagnetic forward technology roadmap, according tothe forward technical route, conducted a formula derivation for Transientelectromagnetic field uniform and isotropic medium layered half-space conditions,acquire the dading source loops layered model time-domain response formula, inforward based on the theory and homogeneous half-space conditions, On the impactof transient electromagnetic response of four factors including the loop length, theemission current, earth resistance point position and receive a comparative analysis,acquire transient electromagnetic response of four factors changing the variationcurves, combined with the actual situation, build five-two or three layered model, by changing the formation thickness and resistivity layers to get different transientelectromagnetic response curve, transient electromagnetic signal attenuation atdifferent speeds resistivity is different, when high resistivity layer decay ratesignificantly faster than in the low-resistivity layer, low discriminating to thin layergeological body, then analysis of transient electromagnetic field technology, from theselected operating parameters, factors exploration, low resistance shield and "blinddeep" problem and determine the four aspects of data quality gives his ownunderstanding, operating parameters according to the actual geological conditionsthrough test selection, great impact on geology and topography of the actual noisedata. At last, combined with practical examples of field work, studied the effect oftransient electromagnetic method of application. In the course of fieldexploration,combined with previous studies based on the actual geologicalconditions and select the appropriate operating parameters and working device FAQconscious prevention. In the data processing, through filtering and terrain correctionfor the actual data were processed, according to the abnormal division and explain theprinciples of the obtained results of the analysis diagram to explain, TEM hasdemonstrated good results in mineral exploration according drilling verification.Meanwhile transient electromagnetic method also has a problem, its shallow missingdata, interpretation needs to be improved under the complicated ground conditions.Through research and application of this article in the hope that actual production inthe future there is a theoretical field exploration and guidance.