L.M. MacCary 1983 <div class="abstract-group "><div class="article-section__content en main"><p>Some logging methods are inherently superior to others for the analysis of limestone and dolomite aquifers. Three such systems are the density, neutron, and acousticvelocity logs.</p><p>Relative percentages of limestone and dolomite, average matrix (grain) densities of the rock mixtures, and porosity of the rock mass can be calculated from density, neutron, and acoustic-velocity logs. Wells drilled before the 1960's generally were logged with an uncalibrated neutron tool. In some instances, the resultant curve can be empirically calibrated.</p><p>With supporting data from resistivity logs, apparent water resistivity (Rwa) can be estimated. Depending on rock and mud resistivities, the two most useful resistivity curves for water-quality studies are the deeply-focused laterolog and the induction log. For older wells, the standard electric log may be used, if the drilling mud is not salt-saturated.</p><p>Rwa contour maps derived from geophysical data are useful to outline areas of recharge, direction of probable ground-water flow, and location and salinity of brine areas. Another useful application of well logs is estimation of ground-water temperature. These temperatures are obtained from maximum-reading thermometer data that generally are recorded on each logging run. Maps of porosity can be used to outline potential areas for completing large-yield wells.</p></div></div> application/pdf 10.1111/j.1745-6584.1983.tb00733.x en National Groundwater Association Geophysical Logging in Carbonate Aquifers article