At Soil Tectonics, we use pedochronology ("soil dating"), as a technique in paleoseismology, the study of prehistoric earthquakes. We combine field observation, soil and geomorphological description, and sampling with laboratory work involving mineralogical, physical, and chemical analyses to discover the relationships between faults and soils. The data are interpreted through perspectives gained from pedochronology, Quaternary stratigraphy, seismology, geodesy, as well as tectonics. Long term goals in this research include the determination of Holocene slip rates, dates of prehistoric events, recurrence intervals, and ultimately, predictions involving the date, magnitude, and location of future earthquakes. Soils are especially important in this work because evidence for the most recent activity usually involves the youngest geologic unit overlying a fault: the soil.
Glenn Borchardt, Principal Soil Scientist, has used this approach in dozens of fault studies in both northern and southern California. The most important involved the proposed Auburn Dam, the proposed Point Conception LNG Terminal, the Vallecitos Reactor near Livermore, USGS-sponsored studies of the Raymond, San Gabriel, Hayward, and Concord faults, as well as numerous evaluations of faults for the state's fault zoning program.
His wide experience in the laboratory and field also is applicable to investigations
in forensic soil science, particularly in legal cases.
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