| Description |
viii, 93 leaves : illustrations, photographs ; 29 cm |
| Summary |
"Electrical exploration methods have been used for many years as a means of determining subsurface structures and in the search for mineral deposits. Vertical profiling techniques can be used to determine rather accurately the resistivity and thichness of horizontal or gently dipping beds for cases up to four layers. Mathematical calculations have been made for multiple layers and theoretical curves have been computed and published for four and more layers. The vertical profiling method is not particularly well suited to the problem of locating lateral changes in resistivity produced by such features as ore bodies, sinks and channels. These features can more easily be determined using the horizontal profiling method. A set of horizontal profile curves, showing the effects of size, depth of burial, and the edges of the various anomalous subsurface features liable to be encountered in the field are desired. It is possible to compute theoretical curves for simple shapes, but many of the features encountered in practice are quite complex. The curves for these complex shapes are impossible to compute, and even for those simple shapes for which curves can be computed the calculations that are necessary are long and laborious. Laboratory investigations of models of geological structures might be a means of providing this needed set of curves. In order to determine if horizontal profile curves could be produced from a laboratory model system, a study was made of the electrical method of exploration as applied to a small scale model system. The necessary equipment was assembled and a number of model measurements was made. To show that the equipment provided results that would be useful and reliable, curves obtained using a model conductive hemisphere were compared with theoretically computed curves for this same case. Finally, a series of measurements was made over several different models and the resulting horizontal profiles are presented as examples of the type of curves that can be produced using a small scale model system"--Introduction, leaves 1-2. |
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