KGS Geophysics in Kansas Original published in D. W. Steeples, ed., 1989, Geophysics in Kansas: Kansas Geological Survey, Bulletin 226, pp. 177-184

Subsurface lithofacies mapping from geophysical logs in Kansas

by John H. Doveton

Kansas Geological Survey
The article is also available as an Acrobat PDF file.


Stratigraphic tops picked from geophysical logs are basic data in the preparation of regional subsurface maps of structure and thickness. These maps are topological-they are restricted to the display of the shape and size of stratigraphic units. However, the quantitative variation of logs with depth can be analyzed in terms of mineralogy and porosity which express the internal composition of these units. Use of computer-mapping packages in a novel way allows this information to be interpolated from available well control in the generation of lithofacies maps. As a practical example, the composition of the Viola Limestone was mapped in a four-county area in southern Kansas through transformation of data from neutron, density, and sonic logs into estimations of calcite, dolomite, chert, and pore volume. Available cuttings and core information were used both to monitor the result and to provide detailed meaning to observed variation. The map shows facies patterns which are readily related to depositional, diagenetic, and erosional trends. In a second example, the statistical moments of the gamma-ray log were used by a computer program to generate three-dimensional trend maps and cross section slices of shale-sand variation in the Simpson Group of the same area. The results give an immediate picture of the shapes and dispositions of major sandstone and sandy carbonate bodies, as well as outlining the areal pattern of a basal transgressive sand.

Kansas Geological Survey
Comments to
Web version Oct. 16, 2013. Original publication date 1989.