Some aspects of computer processing of geophysical prospecting data (Part A.) : Field data case study: Grieve's Quarry, Warwick district, southeast Queensland (Part B.)

Abstract

The aims of this document are three-fold: - to review digital computer software packages available for processing geophysical prospecting data with particular emphasis on ground based surveys, to conduct a literature review of current computer usage in this area, and to apply some of the systems to a geophysical field data case study involving gridded magnetics, topography and self potential data derived from ground-based surveying and profiles of the three data sets together with resistivity, induced polarisation and borehole magnetic susceptibility data. Included are statistical analysesand line printer plotting of assay data from borehole samples.Automated contouring systems presently developed and suitable for the processing of potential field data are reviewed in terms of surface interpolation technique, contour production and general performance in the time and wave number domains in terms of primary data reduction, display and derived mapping. Possible applications of other three dimensional computer graphics display systems for geophysical applications are emphasized. Such displays include isometric diagrams, perspectives, stacked profiles and surface display systems, Mathematical techniques employed for curve tracing of profiles on passive and interactive graphics display devices together with profile interpolation and extrapolation methods amenable to digital computation are reviewed.Geophysical and computer modelling systems oriented to interactive computer graphics usage are detailed. Those applicable to electrical prospecting method and automatic computation of apparent resistivity curves are incorporated together with two and three dimensional gravity and magnetics modelling.Automatic digital map filtering systems are reviewed briefly. Computerised drafting systems of application to geophysical report production are detailed and sample plotted output presented. Briefly discussed are data base management systems currently employed within the earth sciences to accommodate geological/ geophysical files and computer hardware graphics systems suited to geophysical applications.