Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California

This data release provides geochemical and sedimentological data from a 6.2 m section of 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. The data release also includes new and previously published radiocarbon datasets and associated depths to facilitate inter-study comparison relative to the 6.2 m section. 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. 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. (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. 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.

References:
Biasi, G.P. and Weldon II, R., 1994. Quantitative refinement of calibrated 14C distributions. Quaternary Research, 41(1), pp.1-18.
Scharer, K.M., Biasi, G.P. and Weldon, R.J., 2011. A reevaluation of the Pallett Creek earthquake chronology based on new AMS radiocarbon dates, San Andreas fault, California. Journal of Geophysical Research: Solid Earth, 116(B12).
Sieh, K.E., 1978. Prehistoric large earthquakes produced by slip on the San Andreas fault at Pallett Creek, California. Journal of Geophysical Research: Solid Earth, 83(B8), pp.3907-3939.
Sieh, K.E., 1984. Lateral offsets and revised dates of large prehistoric earthquakes at Pallett Creek, southern California. Journal of Geophysical Research: Solid Earth, 89(B9), pp.7641-7670.
Sieh, K., Stuiver, M. and Brillinger, D., 1989. A more precise chronology of earthquakes produced by the San Andreas fault in southern California. Journal of Geophysical Research: Solid Earth, 94(B1), pp.603-623.