# Harding Lake, Alaska 31,000 Year Geochemical Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:15655 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/alaska/harding2014pollen.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2013-12-09 #-------------------- # Title # Study_Name: Harding Lake, Alaska 31,000 Year Geochemical Data #-------------------- # Investigators # Investigators: Finkenbinder, M.S.; Abbott, M.B.; Edwards, M.E.; Langdon, C.T.; Steinman, B.A.; Finney, B.P. #-------------------- # Description_and_Notes # Description: Geochemical data from Harding Lake, Alaska for the last 30,700 yr BP. # Data include dry bulk density, percent organic matter, percent biogenic silica, # magnetic susceptibility, carbon to nitrogen (C/N) mass ratios, bulk # sediment organic matter carbon isotopes (d13C), pollen, and elemental abundances. # #-------------------- # Publication # Authors: Finkenbinder, M.S., Abbott, M.B., Edwards, M.E., Langdon, C.T., Steinman, B.A., Finney, B.P. # Published_Date_or_Year: submitted # Published_Title: A 31,000 Year Record of Paleoenvironmental and Lake-Level Change from Harding Lake, Alaska, USA # Journal_Name: Quaternary Science Reviews # Volume: # Edition: submitted # Issue: # Pages: # DOI: # Online_Resource: # Full_Citation: # Abstract: Physical and geochemical proxy analyses of sediment cores from Harding Lake in central Alaska Alaska are used to reconstruct paleoenvironmental change and millennial scale fluctuations in lake level for the last ~ 31,000 years. We analyzed a composite 422 cm core from the lake depocenter (42.1 m water depth) and identified 4 distinct lithologic units based on variability in dry bulk density, organic matter, biogenic silica, carbon to nitrogen (C/N) mass ratios, organic matter carbon (d13C) isotopes, pollen, and elemental abundances via scanning X-ray fluorescence, with age control provided by 16 Accelerator Mass Spectrometry radiocarbon dates and 210Pb dating. In addition, we analyzed a transect of cores from 7.1m, 10.75m, 15.91m, and 38.05m water depths to identify lake level fluctuations and to characterize shallow water sediments. Organic matter content and magnetic susceptibility values in surface sediments from all transect cores show a strong correlation with water depth. Interpretation of four dated lithologic units produced a record of water-depth variations that is consistent with independent climate records from eastern Beringia. Basal coarse grained sediments (quartz pebble diamicton) were deposited prior to 30,700 calendar years before present (yr BP), possibly due to fluvial reworking or deflation during a period of severe aridity. Unit 1 sediments were deposited between 30,700 and 15,700 yr BP and are characterized by a low organic matter content, a high magnetic susceptibility, and low biogenic silica concentrations resulting from very low lake levels, low terrestrial and in-lake productivity and a significant flux of clastic sediment. An abrupt increase in organic matter and biogenic silica marks the transition into Unit 2 sediments, which were deposited between 15,700 and 9,400 yr BP when lake levels were higher and variable (relative to Unit 1). Unit 3 sediments began forming at 9,400 yr BP, indicating the final transition to full interglacial conditions. Here an abrupt increase in the sedimentation rate, organic matter content, and biogenic silica occurs (along with a corresponding decrease to low magnetic susceptibility). These high values persist until 8,700 yr BP, signifying a rapid rise to higher lake levels (in comparison to Units 1 and 2). Unit 4 sediments were deposited between 8,700 yr BP to 2010 AD and contain generally high concentrations of organic matter and biogenic silica with low magnetic susceptibility, suggesting that lake levels were relatively high and stable during the middle to late Holocene. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: #------------------ # Site_Information # Site_Name: Harding Lake # Location: North America>United States Of America>Alaska # Country: United States # Northernmost_Latitude: 64.42 # Southernmost_Latitude: 64.42 # Easternmost_Longitude: -146.85 # Westernmost_Longitude: -146.85 # Elevation: 217 m #------------------ # Data_Collection # Collection_Name: Harding2014Pollen # Earliest_Year: 30661 # Most_Recent_Year: 259 # Time_Unit: Cal Year BP # Core_Length: m # Notes: Water depth = 42.1 m #------------------ # Chronology: # # Accelerator Mass Spectrometry Radiocarbon ages for Harding Lake, Alaska # # Sample ID Core-Drive Total Depth Material 14C Age Error Calib 6.0 Age (2sigma) # (UCIAMS #) (cm) (yr BP) (yr) (yr BP) # # 89203 C10-D1 22.5 Charcoal 380 30 319-505 # 109356 C10-D1 36.5 Charcoal 1245 25 "1,082-1,267" # 89204 C10-D1 46.5 Wood 1570 40 "1,375-1,541" # 89205 C10-D1 65 Seeds 2700 15 "2,761-2,844" # 89206 C10-D1 101 Wood 4160 45 "4,538-4,834" # 89207 C10-D1 165 Charcoal 6960 70 "7,673-7,935" # 89208 C10-D2 195.5 Charcoal 8000 100 "8,585-9,134" # 89209 C10-D2 200.5 Charcoal 8130 60 "8,795-9,285" # 89210 E10-D2 277.5 Charcoal 8450 80 "9,272-9,550" # 89211 E10-D2 281 Charcoal 8820 160 "9,537-10,233" # 109357 E10-D2 302.5 Charcoal 10310 160 "11,407-12,577" # 109358 E10-D2 320.5 Plant material 10690 190 "12,059-13,068" # 109359 E10-D2 351.5 Seeds 8770 370 "8,787-11,065" * rejected from age model. # 89212 E10-D2 362.5 Wood 13560 100 "16,359-16,967" # 109360 E10-D2 383.5 Plant material 10740 310 "11,643-13,285" * rejected from age model. # 89213 E10-D2 412.5 Charcoal 25900 320 "29,848-31,193" # # 131490 A12-D1 73.5 Seed 12670 380 "13,854-16,526" # # 131489 E12-D1 93.5 Wood 8650 100 "9,468-10,119" # 131489 E12-D2 118.5 Wood 11820 300 "13,093-14,841" # 116879 E12-D2 120.5 Wood 12175 35 "13,872-14,174" # # #---------------- # Variables # # Data variables follow (have no #) # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # Composite core (C-10, D-10, and E-10) pollen percentage data for Harding Lake, Alaska depth_cm depth, , , cm, , , , ,N age_calBP Age, , , calendar years BP, , , , ,N picea Picea, , , percent, , , , ,N betula Betula, , , percent, , , , ,N alnus Alnus, , , percent, , , , ,N salix Salix, , , percent, , , , ,N populus Populus, , , percent, , , , ,N juniperus Juniperus, , , percent, , , , ,N ericales Ericales, , , percent, , , , ,N empetrum Empetrum, , , percent, , , , ,N poaceae Poaceae, , , percent, , , , ,N cyperaceae Cyperaceae, , , percent, , , , ,N artemisia Artemisia, , , percent, , , , ,N isoetes Isoetes, , , percent, , , , ,N myriophyllum Myriophyllum, , , percent, , , , ,N pediastrum Pediastrum, , , percent, , , , ,N equisitem Equisitem, , , percent, , , , ,N sphagnum Sphagnum, , , percent, , , , ,N pre-Q spores pre-Quaternary Spores, , , percent, , , , ,N pre-Q pollen pre-Quaternary Pollen, , , percent, , , , ,N #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: depth_cm age_calBP picea betula alnus salix populus juniperus ericales empetrum poaceae cyperaceae artemisia isoetes myriophyllum pediastrum equisitem sphagnum pre-Q Spores pre-Q Pollen 16 259 29.5 44.6 16.1 0.0 0.2 0.2 0.7 0.0 3.6 1.4 0.2 4.6 0.5 0.7 0.0 2.2 0.0 0.0 19 336 9.9 58.0 19.3 2.3 0.0 0.0 0.5 0.0 4.4 4.8 0.0 4.5 0.0 4.1 0.0 1.4 0.0 0.0 39 1261 44.3 38.8 10.3 0.0 0.0 0.0 0.2 0.0 2.9 2.9 0.2 7.1 0.0 0.6 0.0 2.2 0.0 0.0 57 2220 6.4 60.2 17.7 3.3 0.0 0.2 0.0 0.0 1.9 10.1 0.0 7.9 0.4 0.7 0.2 1.6 0.0 0.0 79 3539 22.5 53.0 16.5 0.0 0.0 0.2 0.5 0.0 4.5 2.8 0.0 4.9 0.2 1.1 0.0 3.0 0.0 0.0 98 4545 29.2 54.1 12.9 1.7 0.0 0.0 0.0 0.0 1.7 0.5 0.0 1.6 0.0 0.7 0.0 1.4 0.0 0.0 119 5573 2.4 66.3 23.6 1.7 0.0 0.0 0.0 0.0 1.9 2.9 0.2 1.1 0.0 0.0 0.0 2.1 0.0 0.0 139 6540 0.5 77.1 16.2 1.7 0.0 0.0 0.0 0.0 3.2 0.7 0.0 1.2 0.0 0.7 0.0 0.9 0.0 0.0 158 7458 10.9 75.3 3.7 0.4 0.0 0.0 0.4 0.0 3.5 5.2 0.4 5.3 0.0 1.9 0.4 3.8 0.0 0.0 190 8647 1.4 88.7 0.7 1.7 0.5 0.7 0.5 0.2 0.0 5.0 0.2 4.2 0.0 2.1 0.0 2.1 0.0 0.0 210 9143 0.9 53.6 0.4 15.3 2.2 1.7 0.4 0.2 11.3 11.8 0.7 0.2 0.0 4.2 0.4 2.5 0.0 0.0 254 9338 0.0 72.8 0.5 10.5 0.0 0.0 0.0 0.0 3.5 7.0 4.0 0.0 0.0 2.6 0.2 0.7 0.0 0.0 278 9506 1.5 61.4 0.9 9.5 0.2 0.2 0.4 0.0 7.5 10.8 6.2 0.6 0.2 0.2 0.0 1.1 0.0 0.0 298 11579 0.4 73.0 0.2 6.9 0.4 0.0 0.0 0.0 3.2 13.4 1.9 0.2 0.4 0.4 0.0 0.4 0.0 0.0 316 12454 1.6 54.8 0.5 7.9 0.5 0.2 0.0 0.0 3.1 27.4 1.9 0.2 0.3 1.5 1.1 0.5 0.0 0.0 333 13815 0.6 55.3 0.2 10.7 1.1 0.4 0.4 0.2 5.1 21.2 2.1 0.2 0.6 2.4 0.2 0.6 0.0 0.0 348 15277 0.8 7.5 0.0 9.1 0.8 1.2 0.4 0.0 11.4 49.6 9.8 0.0 0.4 2.9 1.8 0.7 0.4 1.4 363 16829 6.3 11.1 0.0 10.0 1.1 0.5 0.0 0.0 16.8 40.5 6.8 0.0 3.5 9.7 0.4 3.4 1.7 0.0 373 19624 2.0 8.6 1.0 8.6 0.5 0.0 0.0 0.0 15.7 46.7 7.6 0.0 0.0 8.9 2.5 0.8 1.3 0.0 383 22418 0.8 5.1 0.0 9.4 0.0 5.9 0.8 0.0 30.1 16.4 17.6 0.0 4.5 18.5 0.6 3.0 0.0 0.6 393 25212 1.4 1.9 1.0 9.0 0.5 0.5 0.0 0.0 27.6 21.0 25.2 0.0 1.9 3.1 1.3 3.1 0.0 0.0 403 28006 3.0 5.1 3.0 6.1 1.0 0.0 0.0 0.0 25.3 18.2 28.3 0.0 0.0 5.9 0.0 9.2 0.0 0.0 413 30661 0.4 1.2 0.8 5.8 0.0 1.6 0.4 0.0 41.9 11.6 22.9 0.0 0.8 23.2 0.3 4.9 0.3 0.5