Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024)

This data release provides geochemical, sedimentological, and geochronological data from interbedded fluvial and marsh deposits and radiocarbon dates of the section spanning the last 1500 years from the Pallett Creek paleoseismic site, California. The samples were collected to support paleoenvironmental reconstruction of the site and refine several previous investigations of paleoearthquakes along the San Andreas Fault (Sieh, 1978; Sieh, 1984; Sieh et al., 1989; Biasi and Weldon, 1994; Scharer et al., 2011). Geochemical and sedimentological data include grain size, magnetic susceptibility, dry bulk density, percent total organic matter, and percent total carbonate at contiguous 1 cm spacing and carbon (total C) to nitrogen (total N) ratios and charcoal counts every 4 cm from a 6.2 m section at the Pallett Creek paleoseismic site (34.4557°, -117.8872°). The data release also includes new and previously published radiocarbon datasets and associated depths to facilitate inter-study comparison. These datasets include: (1) New accelerator mass spectrometry (AMS) radiocarbon dates, completed in 2021 and 2022, targeting layers with few or conflicting dates in previous studies at the Pallett Creek paleoseismic site. For these samples, the types of taxa present in selected layers was determined. (2) AMS dates originally reported in Scharer et al. (2011) are included with amended d13C fractionation corrections and are assigned depths to the 6.2 m section at the Pallett Creek paleoseismic site. (3) Depths are assigned for conventional radiocarbon dates previously reported in Sieh (1978), Sieh et al. (1984), Sieh et al. (1989) and Biasi and Weldon (1994). The depth estimates enable use of the original studies with the newer stratigraphic and age data provided in the data release. (4) New radiocarbon dates from the same alluvial surface as the Pallett Creek paleoseismic site that are exposed ~1 km upstream (34.4536°, -117.8980°). This report should be used as the supplementary materials for any publication(s) that uses the sedimentologic and geochemical data or taxa identification or radiocarbon dates and depths reported herein. Revision 2.0 by Katherine M. Scharer on February 6, 2024. To review the changes that were made see 'Versioning.txt' file in the Attached Files section on the data release landing page.