Airborne electromagnetic survey results near the Poso Creek oil field, San Joaquin Valley, California, fall 2016

An airborne electromagnetic survey west of the Poso Creek oil field, located in the southeastern San Joaquin Valley, California, was flown in October 2016 to improve understanding of the hydrogeologic setting and the distribution of groundwater salinity in the area. The airborne electromagnetic data were used to develop resistivity models of the subsurface, where the mean depth of investigation is about 300 meters below the land surface and thus characterizes parts of the Kern River Formation and overlying sediments. Resistivity models along with water table elevation, historical total dissolved solids measurements of water samples from wells, well lithologic records, borehole geophysical logs, and mapped surface geology were used to develop an understanding of local hydrogeologic controls on resistivity. Interpretation of these data indicate the resistivity structure primarily reflects the general lithologic character and geologic structure of the study area, with more subtle influences from variations in saturation and salinity.