ABSTRACT
Southern California has undergone rapid growth since 1945. Undeveloped land is in short supply and land in the highly coveted coastal areas is at a premium. Most remaining open space consists of either public parks or areas with geotechnical problems. Accurate, detailed information describing the subsurface geologic materials and slide geometry was necessary for stability analysis and to determine the susceptibility of the slide to renewed movement. Correlation of the gamma radiation logs was useful in determining stratigraphic relationships and regional structure. More detailed subsurface information was needed for stability analyses by the geotechnical engineers. Correlation between borings in the South Shores landslide was based primarily on the distinctive geophysical marker units obtained from gamma logging. These geophysical marker units were confirmed by incremental correlation of characteristic lithologic units from cores and data from downhole logging of large-diameter borings.
