Preliminary photointerpretation map of landslide and other surficial deposits of the Mount Diablo area, Contra Costa and Alameda Counties, California

The map shows the distribution of landslide and other surficial deposits by presenting the writer's best judgement regarding the origins of the various parts of the present landscape. It is based completely on the interpretation of aerial photographs through a stereoscope, which permits a three-dimentional relief model of the ground surface to be seen, enables the geologist to study and interpret the origins of landforms with considerable ease. In fact, photointerpretation provides many advantages over both ground observations and laboratory studies of surficial materials in the mapping of surficial deposits, particularily for reconnaissance-type studies. Of course, better information can be provided when all aspects of the studyy are integrated. These preliminary photointerpretation maps are the inital stage of a continuing, more detailed study of surficial deposits in the Bay region, but they will hopefully provide map users with immediately useful information about the regional distribution of landslide and other surficial deposits.