Electronic Supplement to
Late Holocene Slip Rate and Age of Prehistoric Earthquakes along the Maacama Fault near Willits, Mendocino County, Northern California

by Carol S. Prentice, Martin C. Larsen, Harvey M. Kelsey, and Judith Zachariasen

Table S1. Radiocarbon Analysis of Charcoal Collected from South Wall of Trench 3

Sample
Number*		 Lab
Number†		 δ13C‡ 14C Age
(yr B.P.)§		 Calibrated Years B.P.‖ Comments
047 136442 −25 4395±30 4870–5045 Faulted Holocene sediments
051 136443 −25 3970±30 4300–4520 Faulted and tilted Holocene sediments
072 136444 −25 1745±35 1550–1770 Faulted Holocene sediments
074 136445 −25 2670±40 2740–2850 Faulted Holocene sediments
075 136446 −25 1045±30 920–1050 Holocene sediments (unfaulted?)
076 136447 −25 4165±35 4580–4830 Faulted Holocene sediments
080 136448 −25 4450±35 4890–5290 Faulted Holocene sediments

*Sample locations are shown in Figure S3.

†Analyses from the Center for Accelerator Mass Spectrometry (CAMS), Lawrence Livermore National Laboratory, Livermore, California.

‡Δ13C assumed to be −25/00.

§Conventional radiocarbon age, expressed as years before 1950. Calculations assume a Libby half-life (5568 yr). Uncertainties are one standard deviation counting errors.

‖Dendrochronologically calibrated calendar-age ranges using the atmospheric decadal dataset of Reimer et al., 2009, two-sigma uncertainty, rounded to nearest decade. Calibration accomplished using CALIB, version 6 (Stuiver and Reimer, 1993) Rev. 6. (see Data and Resources section). B.P. is defined as before 1950.

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