| Sample Number | Laboratory1 Number | Source2 | Material3 | Reported Age, ±1σ (C14 yr B.P.) | MRT4 Correction (yr) | Calibrated Age5 Range, ±2σ (cal yr B.P.) | Calibrated Age5 Weighted Mean, ±2σ (cal yr B.P.) | Comments |
|---|---|---|---|---|---|---|---|---|
| Pole Patch site | ||||||||
| PP-1 | PITT 0093 | 1 | Soil organics | 4,190 ± 125 | 200 ± 200 | 5260-3720 | 4450 ± 650 | MRT age on soil organics eroded from the hanging wall A horizon and deposited in a tectonic crack during or shortly after the most-recent surface rupture at the site; provides close maximum age of earthquake PP1 |
| PP-2 | USGS-2641 | 1 | Soil organics | 2390 ± 100 | 200 ± 200 | 2750-1640 | 2200 ± 560 | MRT age on soil organics from a clast of A-horizon deposited in a post-earthquake-PP1 fluvial deposit; provides probable not-so-close minimum age of earthquake PP1 |
| Bowden Canyon site | ||||||||
| BC-4 | USGS-2536 | 2 | Soil organics | 4330 ± 70 | 200 ± 200 | 5290-4080 | 4640 ± 600 | MRT age on soil organics from soil formed on eroded block of fan alluvium and buried by scarp colluvium from second-oldest surface rupture at site; provides close-maximum age of earthquake BC3 |
| BC-5 | USGS-2535 | 2 | Soil organics | 3430 ± 70 | 100 ± 200 | 3890-3270 | 3580 ± 290 | MRT age on soil organics from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture at site; provides minimum-limiting age of earthquake BC2 and maximum age of earthquake BC1 |
| BC-7 | PITT 0092 | 2 | Soil organics | 1260 ± 60 | 0 | 1300-1060 | 1180 ± 140 | MRT age on soil organics from near base of soil formed on scarp colluvium from most-recent surface rupture at site; provides minimum-limiting age of earthquake BC1 |
| BC-8 | USGS-2604 | 2 | Soil organics | 4340 ± 100 | 200 ± 200 | 5310-4010 | 4660 ± 630 | MRT age on soil organics from soil formed on oldest scarp colluvium and buried by scarp colluvium from second-oldest surface rupture at site; provides minimum-limiting age of earthquake BC-4 and close-maximum age of earthquake BC3 |
| Box Elder Delta site | ||||||||
| na | B-54890 | 3 | Soil organics | 3430 ± 60 | 200 ± 200 | 3970-2890 | 3450 ± 530 | MRT age on soil organics from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture on northern part of scarp G (trench 5); provides minimum-limiting age of earthquake BEX and close-maximum age of earthquake BEY |
| na | B-59101 | 3 | Soil organics | 3160 ± 100 | 200 ± 200 | 3690-2500 | 3130 ± 530 | MRT age on soil organics from near base of soil formed on scarp colluvium from most-recent surface rupture on middle part of scarp G (trench 3); provides minimum-limiting age of earthquake BEY |
| na | B-68253 | 3 | Soil organics | 2630 ± 90 | 200 ± 200 | 2990-1930 | 2480 ± 530 | MRT age on soil organics from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture on scarp D (trench 12); provides close-maximum age of earthquake BEZ |
| na | B-68254 | 3 | Soil organics | 1720 ± 90 | 200 ± 200 | 1890-970 | 1450 ± 470 | MRT age on soil organics from near base of soil formed on scarp colluvium from most-recent surface rupture on scarp D (trench 12); provides minimum-limiting age of earthquake BEZ |
| na | B-68255 | 3 | Soil organics | 3320 ± 80 | 200 ± 200 | 3830-2790 | 3310 ± 530 | MRT age on soil organics from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture on southern part of scarp G (trench 13); provides minimum-limiting age of earthquake BEX and close-maximum age of earthquake BEY |
| na | B-68257 | 3 | Soil organics | 5380 ± 80 | 200 ± 200 | 6400-5470 | 5940 ± 470 | MRT age on soil organics from soil formed on terrace alluvium and buried by scarp colluvium from penultimate surface rupture on southern part of scarp A (trench 14); provides close-maximum age of earthquake BEW |
| na | B-68258 | 3 | Soil organics | 2580 ± 60 | 200 ± 200 | 2880-1900 | 2430 ± 510 | MRT age on soil organics from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture on southern part of scarp A (trench 14); provides close-maximum age of earthquake BEZ |
| OTL-506 | OTL-506 | 3 | Silt from colluvium | 5000 ± 1000 | na | 3000-7000 | 5000 ± 2000 | Thermoluminescence (TL) age on silty (loessy) colluvium from most-recent surface rupture on northern part of scarp A (trench 10, also trench 4), which McCalpin and Forman (2002) infer predates earthquake BEX. We infer correlation with penultimate surface rupture on southern part of scarp A (trench 14), so provides minimum-limiting age of earthquake BEW |
| Hansen Canyon site | ||||||||
| HC-R1 | OS-70586 | 4 | charcoal | 4410 ± 35 | na | 5270-4860 | 5000 ± 200 | Age on small charcoal fragments from soil formed on faulted fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides maximum age of earthquake HC1 |
| HC-R5 | OS-70598 | 4 | charcoal | 2120 ± 35 | na | 1990-2300 | 2100 ± 140 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake HC1 |
| HC-R6 | OS-71479 | 4 | charcoal | 320 ± 60 | na | 500-160 | 380 ± 150 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake HC1; young age may be result of post-depositional bioturbation (rodent burrowing) |
| HC-R7 | OS-70600 | 4 | charcoal | 3840 ± 35 | na | 4410-4150 | 4260 ± 150 | Age on small charcoal fragments from soil formed on faulted fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides maximum age of earthquake HC1 |
| HC-R8 | OS-71479 | 4 | charcoal | 4200 ± 25 | na | 4840-4630 | 4740 ± 120 | Age on small charcoal fragments from soil formed on faulted fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides maximum age of earthquake HC1 |
| HC-R9 | OS-70634 | 4 | charcoal | 725 ± 30 | na | 730-570 | 670 ± 50 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake HC1; young age may be result of post-depositional bioturbation (rodent burrowing) |
| Kotter Canyon site | ||||||||
| KC-R4 | OS-71851 | 4 | charcoal | 2400 ± 120 | na | 2750-2150 | 2480 ± 320 | Age on small charcoal fragments from scarp colluvium from most-recent surface rupture at site; provides close-minimum age of earthquake KC1 |
| KC-R6 | OS-70593 | 4 | charcoal | 530 ± 30 | na | 630-510 | 550 ± 70 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake KC1; young age may be result of post-depositional bioturbation (rodent burrowing) |
| KC-R7 | OS-70602 | 4 | charcoal | 340 ± 30 | na | 480-310 | 390 ± 100 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake KC1; young age may be result of post-depositional bioturbation (rodent burrowing |
| KC-R8 | OS-70595 | 4 | charcoal | 3110 ± 40 | na | 3440-3220 | 3330 ± 100 | Age on small charcoal fragments from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture at site; provides minimum-limiting age of earthquake KC2 and maximum age of earthquake KC1 |
| KC-R11 | OS-70799 | 4 | charcoal | 2300 ± 120 | na | 2710-2010 | 2340 ± 360 | Age on small charcoal fragments from soil formed on penultimate scarp colluvium and buried by scarp colluvium from most-recent surface rupture at site; provides minimum-limiting age of earthquake KC2 and close-maximum age of earthquake KC1 |
| KC-L1 | KC-L1 | 4 | Sand from alluvium | 3595 ± 265 | na | 4125-3065 | 3595 ± 530 | Blue-light, optically-stimulated luminescence (OSL) age on distinctive sand bed in fan alluvium in footwall; same bed in hanging wall underlies scarp colluvium from penultimate surface rupture at site; provides maximum-limiting age of earthquake KC2 |
| KC-L3 | KC-L3 | 4 | Sand from alluvium | 3900 ± 320 | na | 4540-3260 | 3900 ± 640 | Blue-light, optically-stimulated luminescence (OSL) age on distinctive sand bed in fan alluvium in hanging wall that underlies scarp colluvium from penultimate surface rupture at site; provides maximum-limiting age of earthquake KC2 |
| KC-L1-L3 mean age | na | 4 | Sand from alluvium | 3670 ± 205 | na | 4080-3260 | 3670 ± 410 | Weighted mean of OSL ages KC-L1 and KC-L3 used in OxCal analysis (Fig. 2); provides close maximum-limiting age of earthquake KC2 |
| Pearsons Canyon site | ||||||||
| PCN-R2 | OS-70603 | 4 | charcoal | 1270 ± 30 | na | 1290-1090 | 1220 ± 80 | Age on small charcoal fragments from scarp colluvium from most-recent surface rupture at site; provides close-minimum age of earthquake PC1 |
| PCN-R4 | OS-70604 | 4 | charcoal | 1810 ± 30 | na | 1820-1630 | 1750 ± 100 | Age on small fragments of conifer charcoal from soil formed on fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides maximum-limiting age of earthquake PC1 |
| PCN-R6a | OS-70605 | 4 | charcoal | 795 ± 30 | na | 770-670 | 710 ± 40 | Age on small charcoal fragments from scarp colluvium from most-recent surface rupture at site; provides minimum age of earthquake PC1; young age may be result of post-depositional bioturbation (rodent burrowing) |
| PCN-R7 | OS-70606 | 4 | charcoal | 1320 ± 25 | na | 1300-1180 | 1250 ± 70 | Age on small charcoal fragments from debris flow that overlies scarp colluvium from most-recent surface rupture at site; provides close-minimum age of earthquake PC1 |
| PCN-R8 | OS-71769 | 4 | charcoal | 2110 ± 65 | na | 2310-1930 | 2100 ± 200 | Age on small charcoal fragments from soil formed on fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides maximum-limiting age of earthquake PC1 |
| PCN-R9 | OS-70609 | 4 | charcoal | 1280 ± 30 | na | 1290-1150 | 1220 ± 80 | Age on small charcoal fragments from soil formed on fan alluvium and buried by scarp colluvium from most-recent surface rupture at site; provides close-maximum-limiting age of earthquake PC1 |
1Radiocarbon Laboratory identifier: B—Beta Analytic, Miami, Florida, PITT—University of Pittsburg Applied Research Center Radiocarbon Laboratory; OS—National Ocean Sciences Accelerator Mass Spectrometry Facility, Woods Hole Oceanographic Institution; USGS—U.S. Geological Survey, Menlo Park Radiocarbon Laboratory; Luminescence Laboratory identifier: OTL—University of Illinois at Chicago Luminescence Dating Research Laboratory; KC-L—USGS Luminescence Dating Laboratory, Denver, CO.
2Published sources of chronological information: 1) Personius, 1991b; 2) Personius (1991a); 3) McCalpin and Nishenko (1996) and McCalpin and Forman, 2002; 4) DuRoss et al. (2012).
3Two types of organic matter were radiocarbon dated: soil organics—fine (<63 micron) mixtures of organic matter concentrated from bulk samples of soil A-horizons; these samples were conventionally dated using gas-proportional or beta counting techniques; charcoal—Small fragments of wood charcoal, commonly concentrated from bulk samples of soil A horizons; these samples were identified to species level when possible and dated using Accelerator Mass Spectrometry (AMS) techniques. Luminescence samples primarily consisted of fine silt grains of mixed mineralogy (thermoluminescence or TL age OTL-506) or fine sand grains of quartz (blue-light optically stimulated luminescence or OSL ages KC-L1, KC-L2, KC-L3).
4Mean residence time (MRT), subtracted from reported B.P. ages on soil organics samples before calibration; in most cases values follow those used by original sources.
5Radiocarbon calibration ages derived from reported B.P. ages (less MRT estimates for soil organics samples) prior to modeling, using OxCal software (Bronk-Ramsey, 1995, 2001, 2008) version 4.1.7 and IntCal09 calibration curve from Reimer et al. (2009).
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