Shannon A. Mahan Emma T. Krolczyk Leticia P. Hallas Amy E. East John R. Wood 20250819 CSV Denver, CO U.S. Geological Survey https://www.sciencebase.gov/catalog/item/67b50654d34eabd207200234 https://doi.org/10.5066/P1339SXQ Jack Wood Shannon A. Mahan Eric L. Bilderback Amy East Emma T. Krolczyk Brian Radmussen Karina S. Zyatitsky Liticia P. Hallas 2026 1 publication Cambridge University Press Quaternary Research This report summarizes the dating results from sedimentary deposits sampled by the National Park Service and the U.S. Geological Survey and analyzed at the USGS Luminescence Geochronology Laboratory. Within this report, we detail the luminescence measurement, equivalent dose determination, and dating-related calculations. We recommend that this report be included as the supplementary material for any publication (s) that use the ages within this report. This data supports a publication that produces ages on debris flow (mass waste events) which are in turn driven by wildfires across the landscape. There are three items of data: luminescence, radiocarbon, and charcoal counting. 2022 ground condition Complete None planned -122.59510 -122.54116 40.61620 40.58074 ISO 19115 Topic Category farming USGS Thesaurus luminescence dating optically-stimulated luminescence age estimation methods geochronology radiation dosimetry debris flows USGS Metadata Identifier USGS:67b50654d34eabd207200234 USGS Thesuarus Klamath Mountains Northern California Brandy Creek Clear Creek Whiskeytown National Recreation Area Trinity Range None. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Shannon A Mahan U.S. Geological Survey, ROCKY MOUNTAIN REGION Research Geologist mailing address

Mail Stop 963, W 6th Ave Kipling St

Lakewood CO 80225 US 303-236-7928 303-236-5556 smahan@usgs.gov National Park Service No formal attribute accuracy tests were conducted. Map elements and topography were checked if needed. Again, no formal logical accuracy tested were conducted. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. 0.1000 0.1000 All samples were prepared for dating using standard procedures of Mahan et al. (2015) and Nelson et al. (2015) at the USGS luminescence lab in Denver, Colorado. Subsamples for equivalent dose (DE) measurements (i.e. natural luminescence accumulations) were obtained from the center of the core tubes. The end portion of the sample tubes (∼3-4 cm) were used for moisture and elemental concentrations. These sub samples were dried in an oven at 30o C, homogenized, packaged, and analyzed at the USGS Gamma Spectrometry facility to determine radioisotope concentrations for the dose rate. The middle part of the tube sample was sieved to 90-250 microns, leached in 10% HCl for 24 hours, and then in 30% H2O2 for 24 hours. The 90-250 micron quartz and feldspar fractions were separated from magnetic and heavy minerals using a Franz magnetic separator and heavy liquids (lithium sodium polytungstate or LST; density=2.58 gcm-3 for feldspar). Feldspar grains were lightly etched in 10% HF for 5 minutes, rinsed, dried and then measured for luminescence. A single grain thick layer of refined feldspar grains (~50-150 grains) was dispersed onto steel discs pre-prepared with a 1 mm “mask” of silica spray. About 15-40 aliquots were measured to ensure reliable statistical trends (Rodnight, 2008). The dose rate was obtained through elemental data analyses. The concentrations of K, U, and Th were determined using gamma spectrometry following the procedures described in Snyder and Duval (2003). The gamma-ray spectrometer provides the isotopic discrimination of gamma rays; correspondingly, beta and alpha dose rates may be estimated. In the laboratory, the bulk samples were counted in a low-resolution gamma spectrometer fitted with a germanium detector. Measured elemental concentrations, associated dose rates, and cosmic ray contributions are presented in Table 3. Cosmic-ray dose rate data was estimated for each sample as a function of depth, elevation above sea level, and geomagnetic latitude and added to the total dose rate (Prescott and Hutton, 1994). 2022 Sediment samples were collected from the matrix of debris-flow deposits (and alluvial/fluvial deposits at the Bluebird meadow) and analyzed for charcoal abundance at the U.S. Geological Survey laboratory in Santa Cruz, California, following the methods of Anderson et al. (2023). Charcoal abundance was analyzed in 1.23-ml sediment samples (i.e., one quarter teaspoon, a known volume collected in situ). The samples were treated with 6% sodium hypochlorite solution (bleach), agitating the samples slowly in a 50-ml test tube for two hours. The samples were then wet-sieved at 125 µm (0.125 mm), and the fraction coarser than 125 µm washed into petri dishes and oven-dried at 50oC. Analyses are performed on the fraction coarser than 125 µm (0.125 mm) because smaller charcoal particles become difficult to distinguish from dark lithic grains even under high magnification. The dried samples were examined under a binocular microscope at 15x magnification using a gridded background to facilitate accurate, thorough counting coverage. To ensure consistency, all samples were counted by the same technician. We report the data as the number of charcoal particles >125 µm per unit volume (1.23 ml). 20220626 0.00001 0.00001 Decimal degrees Table Name,Field Name,Description,Units,Valid Values or Range Whiskeytown_Luminescence_Data,Sample_ID,Collector's sample name,n/a,n/a Whiskeytown_Luminescence_Data,Unique_ID,Unique identifier for IWP database.,n/a,n/a Whiskeytown_Luminescence_Data,Data_Source_ID,Unique identifier of citation where data are published.,n/a,n/a Whiskeytown_Luminescence_Data,Parent_ID,Unique identifier of parent - 'sample_id',n/a,n/a Whiskeytown_Luminescence_Data,Parent_Rel,"Relationship to parent, e.g., sample X from parent_id soil profile",n/a,n/a Whiskeytown_Luminescence_Data,Lum_ID,Unique identifier for analysis from analyzing laboratory,n/a,n/a Whiskeytown_Luminescence_Data,Laboratory,Name of Laboratory producing the age,n/a,n/a Whiskeytown_Luminescence_Data,Quad,Quadrangle that the sample was collected from,n/a,n/a Whiskeytown_Luminescence_Data,Latitude,Latitude of sample,Degrees,40.58074 to 40.61620 Whiskeytown_Luminescence_Data,Longitude,Longitude of sample ,Degrees,-122.59505 to -122.54116 Whiskeytown_Luminescence_Data,Elevation(m),Elevation of sample in meters above sea level,Meters,285 to 525 Whiskeytown_Luminescence_Data,Depth(cm),Depth of sample below modern surface in cm,Centimeters,20 to 2500 Whiskeytown_Luminescence_Data,Field_Moisture(Percent),The water content in weight percent of the sample as initially extracted from the sample container,Percentage,2 to 18 Whiskeytown_Luminescence_Data,Saturation_Moisture(Percent),The water content in weight percent of the sample after the sample has been saturated with water,Percentage,30 to 55 Whiskeytown_Luminescence_Data,K_Percent,The weight percent of potassium as measured by ICP-MS or Gamma spectrometry,Percentage,0.82 to 1.92 Whiskeytown_Luminescence_Data,K_Percent_Error,The uncertainty (in weight percent) of the potassium weight percent,Percentage,0.02 to 0.05 Whiskeytown_Luminescence_Data,U_ppm,The concentration of uranium in parts per million (ppm) as measured by ICP-MS or Gamma spectrometry,Parts per million,0.76 to 2.02 Whiskeytown_Luminescence_Data,U_ppm_Error,The uncertainty (in ppm) of the uranium concentration,Parts per million,0.1 to 0.19 Whiskeytown_Luminescence_Data,Th_ppm,The concentration of thorium in parts per million (ppm) as measured by ICP-MS or Gamma spectrometry,Parts per million,2.83 to 6.24 Whiskeytown_Luminescence_Data,Th_ppm_Error,The uncertainty (in ppm) of the thorium concentration,Parts per million,0.17 to 0.51 Whiskeytown_Luminescence_Data,Rb_ppm,Rubidium concentration in sample in parts per million,Parts per million,n/a Whiskeytown_Luminescence_Data,Rb_ppm_Error,Rubidium concentration uncertainty in parts per million,Parts per million,n/a Whiskeytown_Luminescence_Data,Cosmic_Dose_Rate(Gy/ka),The contribution of cosmic radiation to the background ionizing dose rate calculated by DRAC (in Gray/ka),Gray/ka,n/a Whiskeytown_Luminescence_Data,Cosmic_Dose_rate_Error,The uncertainty in the cosmic dose rate (in Gray/ka),Gray/ka,n/a Whiskeytown_Luminescence_Data,Total_Dose_Rate_Quartz,Luminescence dose rate in Grays per thousand years (quartz),Gray/ka,1.37 to 2.76 Whiskeytown_Luminescence_Data,Total_Dose_Rate_Quartz_Error,1 sigma uncertainty in equivalent dose for in Grays (quartz),Gray,0.05 to 0.14 Whiskeytown_Luminescence_Data,Total_Dose_Rate_Feldspar,Luminescence dose rate for in Grays per thousand years (feldspar),Gray/ka,1.99 to 2.57 Whiskeytown_Luminescence_Data,Total_Dose_Rate_Feldspar_Error,1 sigma uncertainty in dose for feldspar in Grays (feldspar),Gray,0.08 to 0.12 Whiskeytown_Luminescence_Data,Dose_Rate_Ref,Literature reference and/or link to original data source,n/a,n/a Whiskeytown_Luminescence_Data,Grain_Size_Min(µm),Maximum grain size of the treated sample in microns,microns,180 Whiskeytown_Luminescence_Data,Grain_Size_Max(µm),Minimum grain size of the treated sample in microns,microns,250 Whiskeytown_Luminescence_Data,Age_Model_Used,Age model used to provide preferred age,n/a,n/a Whiskeytown_Luminescence_Data,Analysis_Type_Qtz,"Type of luminescence analysis for quartz (OSL, IRSL, TL, etc.)",n/a,n/a Whiskeytown_Luminescence_Data,Instrumental_Method_Qtz,Method of luminescence analysis (quartz),n/a,n/a Whiskeytown_Luminescence_Data,Aliquots_Passed_Qtz,Number of aliquots measured that passed acceptance criteria (quartz),n/a,2 to 20 Whiskeytown_Luminescence_Data,Alliquots_Total_Qtz,Number of aliquots measured for sample (quartz),n/a,18 to 45 Whiskeytown_Luminescence_Data,Equiv_Dose_Quartz,Equivalent dose of luminescence in Grays (quartz),Gray,0.39 to 18.4 Whiskeytown_Luminescence_Data,Equiv_Dose_Quartz_Error,1 sigma uncertainty in equivalent dose in Grays (quartz),Gray,0.03 to 0.34 Whiskeytown_Luminescence_Data,Equiv_Dose_Quartz_Scatter,Scatter of equivalent dose of luminescence in percentage (quartz),Percentage,30 to 105 Whiskeytown_Luminescence_Data,MAM_Age_Quartz(yrs),Luminescence age provided by the minimum age model (quartz),Years,280 to 6840 Whiskeytown_Luminescence_Data,MAM_Age_Quartz_Error(yrs),Luminescence age uncertainty provided by the minimum age model (quartz),Years,30 to 440 Whiskeytown_Luminescence_Data,CAM_Age_Quartz(yrs),Luminescence age provided by the central age model (quartz),Years,1090 to 21960 Whiskeytown_Luminescence_Data,CAM_Age_Quartz_Error(yrs),Luminescence age uncertainty provided by the central age model (quartz),Years,150 to 2890 Whiskeytown_Luminescence_Data,Mean_Age_Quartz(yrs),Luminescence age provided by the weighted mean (quartz),Years,700 to 15040 Whiskeytown_Luminescence_Data,Mean_Age_Quartz_Error(yrs),Luminescence age uncertainty provided by the weighted mean (quartz),Years,40 to 860 Whiskeytown_Luminescence_Data,Preferred_Age_Qtz(yrs),Preferred luminescence age of sample in thousands of years (quartz),Thousands of years,280 to 13380 Whiskeytown_Luminescence_Data,Preferred_Age_Quartz_Error(yrs),Preferred luminescence age error in thousands of years (quartz),Thousands of years,30 to 760 Whiskeytown_Luminescence_Data,Analysis_Type_Fld,"Type of luminescence analysis for feldspar (OSL, IRSL, TL, etc.)",n/a,n/a Whiskeytown_Luminescence_Data,Instrumental_Method_Fld,Method of luminescence analysis (feldspar),n/a,n/a Whiskeytown_Luminescence_Data,Aliquots_Passed_Fld,Number of aliquots measured that passed acceptance criteria (feldspar),n/a,2 to 6 Whiskeytown_Luminescence_Data,Alliquots_Total_Fld,Number of aliquots measured for sample (feldspar),n/a,15 to 18 Whiskeytown_Luminescence_Data,Equiv_Dose_Feldspar,Equivalent dose of luminescence in Grays (feldspar),Gray,8.6 to 53.6 Whiskeytown_Luminescence_Data,Equiv_Dose_Feldspar_Error,1 sigma uncertainty in equivalent dose in Grays (feldspar),Gray,1.1 to 2.8 Whiskeytown_Luminescence_Data,Equiv_Dose_Feldspar_Scatter,Scatter of equivalent dose of luminescence in percentage (feldspar),Percentage,36 to 66 Whiskeytown_Luminescence_Data,MAM_Age_Feldspar(yrs),Luminescence age provided by the minimum age model (feldspar),Years,3350 to 26020 Whiskeytown_Luminescence_Data,MAM_Age_Feldspar_Error(yrs),Luminescence age uncertainty provided by the minimum age model (feldspar),Years,450 to 1660 Whiskeytown_Luminescence_Data,CAM_Age_Feldspar(yrs),Luminescence age provided by the central age model (feldspar),Years,8180 to 45630 Whiskeytown_Luminescence_Data,CAM_Age_Feldspar_Error(yrs),Luminescence age uncertainty provided by the central age model (feldspar),Years,940 to 5590 Whiskeytown_Luminescence_Data,Mean_Age_Feldspar(yrs),Luminescence age provided by the weighted mean (feldspar),Years,5990 to 33860 Whiskeytown_Luminescence_Data,Mean_Age_Feldspar_Error(yrs),Luminescence age uncertainty provided by the weighted mean (feldspar),Years,540 to 1470 Whiskeytown_Luminescence_Data,Uncorrected_Preferred_Age_Fld,Preferred luminescence age of sample before fading adjustment in thousands of years (feldspar) ,Thousands of years,3350 to 26020 Whiskeytown_Luminescence_Data,Uncorrected_Preffered_Age_Fld_Error(yrs),Preferred luminescence age before fading adjustment uncertainty in thousands of years (feldspar) ,Thousands of years,450 to 1660 Whiskeytown_Luminescence_Data,Fading_Rate(G/decade),Fading rate of feldspar sample (in G/decade),G/decade,n/a Whiskeytown_Luminescence_Data,Fading_Rate_Error(G/decade),Fading rate of feldspar sample uncertainty (in G/decade) ,G/decade,n/a Whiskeytown_Luminescence_Data,Modeled_Age_Fld,Modeled luminescence age of sample after fading adjustment (feldspar),Years,n/a Whiskeytown_Luminescence_Data,Modeled_Age_Fld_Error(yrs),Uncertainty of modeled luminescence age of sample after fading adjustment (feldspar),Years,n/a Whiskeytown_Luminescence_Data,Sample_Comments,"Free text to describe features of a sample such as its components, texture, color, shape, etc.",n/a,n/a Whiskeytown_Radiocarbon_Data,Project_ID,Project name,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_ID,Collector's sample name,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Type,Type of sample collected,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Material,Material that was analyzed,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Unit,Unit the sample was taken from,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Date,Date sample was collected ,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Test_Flag,Lab reported inconsistencies,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Reliability,Lab opinion from expert,n/a,n/a Whiskeytown_Radiocarbon_Data,Quad,Quadrangle that the sample was collected from,n/a,n/a Whiskeytown_Radiocarbon_Data,Latitude,Latitude of sample,Degrees,40.58086 to 40.61613 Whiskeytown_Radiocarbon_Data,Longitude,Longitude of sample ,Degrees,-122.57336 to -122.54121 Whiskeytown_Radiocarbon_Data,Elevation(m),Elevation of sample in meters above sea level,Meters,285 to 377 Whiskeytown_Radiocarbon_Data,Laboratory,Name of Laboratory producing the age,n/a,n/a Whiskeytown_Radiocarbon_Data,Lab_Sample_ID,Laboratory's sample name,n/a,n/a Whiskeytown_Radiocarbon_Data,Lab_Test_Date,Date sample was analyzed,n/a,n/a Whiskeytown_Radiocarbon_Data,Lab_Notes,Notes from the laboratory that the sample was analyzed,n/a,n/a Whiskeytown_Radiocarbon_Data,Analysis_Type,Unique analysis type identifier.,n/a,n/a Whiskeytown_Radiocarbon_Data,Fraction_Modern,"Measurement of the deviation of the 14C/12C ratio of a sample from ""Modern""",n/a,0.5657 to 0.9703 Whiskeytown_Radiocarbon_Data,Fraction_Modern_Error,Error of the Fraction Modern measurement,n/a,0.0015 to 0.002 Whiskeytown_Radiocarbon_Data,Uncalibrated_Age(yrs),Without ajustment for calibrated radiocarbon curves,Years,240 to 4580 Whiskeytown_Radiocarbon_Data,Uncalibrated_Age_1Sigma(yrs),Error without calibration,Years,15 to 20 Whiskeytown_Radiocarbon_Data,Delta_14C,The difference in measured 14C from modern 14C,n/a,-439.24 to -38.12 Whiskeytown_Radiocarbon_Data,Calibrated_Age(yrs),Most probable age with calibration curves,Years,355 to 5340 Whiskeytown_Radiocarbon_Data,Calibrated_Age_2Sigma(yrs),Error on calibration curves,Years,20 to 40 Whiskeytown_Radiocarbon_Data,Calibration_Curve,Program used to obtain the calibration curves,n/a,n/a Whiskeytown_Radiocarbon_Data,Sample_Comments,"Free text to describe features of a sample such as its components, texture, color, shape, etc.",n/a,n/a Whiskeytown_Charcoal_Data,Collection_date,Date sample was collected ,n/a,n/a Whiskeytown_Charcoal_Data,Sample_name,Collector's sample name,n/a,n/a Whiskeytown_Charcoal_Data,Latitude,Latitude of sample,Degrees,40.58086 to 40.61613 Whiskeytown_Charcoal_Data,Longitude,Longitude of sample ,Degrees,-122.594217 to -122.541210 Whiskeytown_Charcoal_Data,Lab_analysis_date,Date sample was received,n/a,n/a Whiskeytown_Charcoal_Data,Count_date,Date sample was analyzed,n/a,n/a Whiskeytown_Charcoal_Data,Charcoal_count,The number of charcoal particles >125 µm per unit volume,n/a,0 to 101 Whiskeytown_Charcoal_Data,Notes,Notes from the laboratory the analysis was conducted ,n/a,n/a Whiskeytown_Data_Dictionary.csv GS ScienceBase U.S. Geological Survey mailing address

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey. Although this information product, for the most part, is in the public domain, it also contains copyrighted materials as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. Digital Data https://doi.org/10.5066/P1339SXQ None 20250819 Shannon A Mahan U.S. Geological Survey, ROCKY MOUNTAIN REGION Research Geologist mailing address

Mail Stop 963, W 6th Ave Kipling St

Lakewood CO 80225 US 303-236-7928 303-236-5556 smahan@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998