Transmission Electron Microscopy (tem) And Rs Joint Interpretation Techniques In The Dachang Mine

TEM (Transient Electromagnetic Methods) is a method of time fieldand it is effective to explore the concealed deposit. TEM measures thepure secondary field and is featured in strong ability of distinguishing andlittle influence of terrain.The combination of all kinds of geophysical fields or geophysicaldata is a development direction. The advantage of combined inversion isthat it has higher resolution than the single geophysical inversion method,to some degree it also controls the multi-results of the problems.Firstly, the paper summarizes the fundamental of TEM, the ordinarycurve's characteristic form of geophysical model's transientelectromagnetic response, all kinds of influential factors, methods offieldwork and data explanation of transient electromagnetic. All of thesecontents apply to the application of TEM the theoretic basis and theessential method technology.The author analyzes the existent joint problems of the combinationinversion of TEM and RS (Resistivity Sounding). RS measures thepotential difference under polars of A and B and the symmetricalmeasured points M and N. TEM measures the induction potentialattenuation with the time under circle loop-line device. The measureddata respectively transform to apparent resistivity value at different polarand different attenuation time.By all appearances, the apparent resistivity is the external reflectionof the same underground medium, but the measured field by resistivitymethod is totally different from the field measured by electromagneticmethod. Both of them have no consistency, so the results only have therelatively independent meaning. In fact, TEM measures the apparentresistivity at the time of forepart, or afternoon, or all of the time. How tounify the apparent resistivity at different meaning and different methodsis a problem for the combination inversion——combination inversion ofTEM and RS.The common method adopts equal value line to combine RS andTEM. Apparently, apparent resistivity will produces the contrivedabnormal point at the joint. According to the correlation of TEM and RS apparent-resistivity, transient electromagnetic all time apparent resistivity(middle and later the measure time) and direct current electrical soundingdata are close or binary, so we can find a curve to synthetize the TEM andRS measurement, which factually reflects the electrical property ofunderground medium.Both the apparent resistivity of superficial part RS and deeplyingTEM can reflect the electrical property of geoelectric cross section. Theauthor puts forward a weighted average (weighted mean) join pointprocessing technique, which superficial part RS apparent resistivity ismore important to the combination inversion than the deeplying TEMdoes.With model experiment and Dachang tin-polymetallic ore factualmeasured data processing, it indicates that multi- weighted average(weighted mean)join point processing technique is effective.