This data set contains individual single-grain post-Infrared Infrared Stimulated Luminescence (p-IR IRSL) ages from a paleoseismic trench excavated on the Banning strand of the southern San Andreas Fault in southern California. The trench was excavated on the flood plains of the lower Mission Creek. The trench represents a closed graben deposit with suspended silts to the north and coarse sandy and gravelly units to the south. Castillo et al. (2020) offered a more detailed stratigraphic log and the paleoseismic history of the trench. We collected eleven luminescence samples on March 14th, 2017, and six samples on May 21st, 2017, from the east and west trench walls on the Banning strand. We processed and measured the p-IR IRSL samples at the University of California, Los Angeles Luminescence laboratory. In this data set, we provided the Field Code, Grain size (µm), External K (%), External Th (ppm), External U (ppm), User external gamma dose rate (Gray ka-1), Internal K (%), Depth (meter), Water content (%), Latitude (◦North), Longitude (◦West), Elevation (meter above sea level), and Total dose-rate (Gray/ka) for each sample. In addition, Laboratory code, Equivalent dose (Gray), and Post IR IRSL age (ka) for each grain in each sample are provided. We estimated the total dose rates and the ages on the DRAC online calculator. No fading was observed during the laboratory experiment, and hence we did not perform any correction. Our analysis of the individual single-grain p-IR IRSL ages reveals multiple overlapping subpopulations at least eight times throughout the Holocene, identified using the Finite Mixture Model (FMM). These FMM-subpopulation ages likely represent significant depositional periods in the Mission Creek catchment. These depositional periods show a reasonably good correspondence with the significantly wetter climate in southern California during the Holocene, as demonstrated by the local and regional hydroclimatic proxy data. These geochronologic data sets are useful to seismologists, geomorphologists, paleoclimatologists, and geochronologists alike.

Geolocations: Median lat. 33.9172°, Median long. -116.538°, South-bound lat. 33.9172°, West-bound long. -116.538°, North-bound lat. 33.9172°, East-bound long. -116.538°. Parameters: Laboratory code, Field Code, Grain size (µm), External K (%), External Th (ppm), External U (ppm), User external gamma dose rate (Gray ka-1), Internal K (%), Depth (meter), Water content (%), Latitude (◦North), Longitude (◦West), Elevation (meter above sea level), Total dose-rate (Gy/ka) ± 1σ, Equivalent dose (Gray) ± 1σ, Post IR IRSL age (ka) ± 1σ.