# Seweweekspoort, South Africa 22,300-year Rock Hyrax Midden Stable Isotope Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # 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: https://www.ncdc.noaa.gov/paleo/study/28131 # Description: NOAA Landing Page # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/midden/africa/seweweekspoort2017d15n-comp.txt # Description: NOAA location of the template # # Original_Source_URL: # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Other Collections # # Dataset DOI: # # Parameter_Keywords: #--------------------------------------- # Contribution_Date # Date: 2019-10-30 #--------------------------------------- # File_Last_Modified_Date # Date: 2019-10-30 #--------------------------------------- # Title # Study_Name: Seweweekspoort, South Africa 22,300-year Rock Hyrax Midden Stable Isotope Data #--------------------------------------- # Investigators # Investigators: Chase, B.M.; Chevalier, M.; Boom, A.; Carr, A.S. #--------------------------------------- # Description_Notes_and_Keywords # Description: Stable isotope (d15N and d13C) data from rock hyrax middens collected in Seweweekspoort, South Africa, for the past 22,300 years. # Rock hyrax middens – the communal latrines of the rock hyrax (Procavia capensis) – accumulate over thousands of years and preserve continuous records of past climate change (Chase et al., 2012). # Six middens from two sites within Seweweekspoort (SWP-1; 33.367S, 21.414E and SWP-3; 33.409S, 21.403E) were selected for analysis because they are composed almost entirely of hyraceum (no visible faecal pellets). # Our experience has demonstrated that such middens have superior stratigraphic integrity compared to more pellet-rich middens (Chase et al., 2012). Representative portions of the middens were processed following Chase et al. (2013; 2012). # Radiocarbon age determinations (n=36) were processed at the 14CHRONO Centre, Queen's University Belfast using accelerator mass spectrometry (AMS). The radiocarbon ages were corrected for isotope fractionation using the AMS measured d13C # and calibrated using the SHCal13 calibration data (Hogg et al., 2013). The Bacon 3.0.3 software package (Blaauw and Christen, 2011) was used to generate all age-depth models (Figure S1). Results indicate that these sequences # continuously span the last 22,300 years. The stable nitrogen (15N) and carbon (13C) isotope contents of 767 overlapping hyraceum samples were measured at the Department of Archaeology, University of Cape Town following Chase et al. (2010; 2009; 2011; 2012), # with contiguous/overlapping samples obtained from two series of offset 1 mm holes. For the stable isotope analyses, the standard deviation derived from replicate analyses of homogeneous material was better than 0.2 per mil for both nitrogen and carbon. # Nitrogen isotope results are expressed relative to atmospheric nitrogen. Carbon isotope results are expressed relative to Vienna PDB. The carbon isotopic composition of the hyraceum is representative of vegetation around a midden site (Carr et al., 2016) # and provides information on 1) the relative contribution of C3, C4 and CAM plants (Smith, 1972) to the animals' diet, and 2) variations in plant water-use efficiency (WUE) as a function of climate (Ehleringer and Cooper, 1988; Farquhar et al., 1989; # Farquhar and Richards, 1984; Pate, 2001). Throughout the broader region, the distribution of C3 and C4 grasses tracks the proportion of winter versus summer rainfall (Vogel, 1978). At Seweweekspoort today, grasses are a mosaic of C3 and C4 varieties # (Rutherford et al., 2012; Rutherford et al., 2003; SANBI, 2003), and where aspect and soil depth limit soil water content, succulent CAM plants become increasingly abundant. As C3 plants are depleted in 13C compared with most CAM and all C4 plants, # higher d13C values indicate more abundant warm season (C4) grasses and/or CAM plants, and generally warmer/more arid conditions. Hyraceum d15N is an indicator of changes in ecosystem water-availability (Carr et al., 2016; Chase et al., 2013; # Chase et al., 2015b; Chase et al., 2009; Chase et al., 2011). A positive relationship exists between aridity and d15N in soils, plants and hyraxes, with drier conditions correlating with enriched 15N (Carr et al., 2016). This most likely reflects # denitrification processes in arid/semi-arid soils (Handley et al., 1999; Handley et al., 1994; Hartman, 2011; Heaton, 1987; Murphy and Bowman, 2006, 2009; Wang et al., 2010), and has been observed in other herbivores in dryland regions # (Ambrose and DeNiro, 1986; Hartman, 2011; Murphy and Bowman, 2006). In hyraceum samples, the narrowly defined feeding range of the hyraxes (<60 m; Sale, 1965), and the accumulation rates of the middens (~20-60 years/sample in most cases) # enforces a spatio-temporal averaging that reduces the d15N variability observed in modern ecosystem studies (Carr et al., 2016), and provides a more reliable index of past water variability (Carr et al., 2016; Chase et al., 2012). # Results from each of the different Seweweekspoort rock hyrax middens overlap such that they can be combined to create a 22,300-year composite records for the sites. To achieve this, the stable isotope data were combined using # Local Regression (LOESS) curve fitting of the combined datasets. As individual middens under the same climate regime may exhibit differences in their isotopic records due to microclimatic influences (Carr et al., 2016) on individual foraging ranges # (i.e. baseline d15N variability), prior to LOESS curve fitting all records were normalised using a standard score and we adjusted the d15N to account for these differences. Using the SWP-1-1 and SWP-1-4b records as a datum, an estimated offset # of 1.5 per mil was added to the d15N data from the SWP-3-1 to compensate for the more humid microclimate in which the midden was found, and 0.5 per mil and 1 per mil were added to SWP-1-5 and SWP-1-2a respectively to account for their more exposed positions. # This accounts for some, but not all, differences between the midden records. The d15N record from SWP-1-5, for instance, presents an anomalous signal, which Chase et al. (2013) attribute to be primarily a function of both the position of the midden # and the lower resolution of the record. Overall, however, we find that the composite record created from these datasets is coherent at orbital and millennial scales. # Provided Keywords: hydroclimate, Holocene, last glacial-interglacial transition, Last Glacial Maximum #--------------------------------------- # Publication # Authors: Brian M. Chase, Manuel Chevalier, Arnoud Boom, Andrew S. Carr # Published_Date_or_Year: 2017-10-15 # Published_Title: The dynamic relationship between temperate and tropical circulation systems across South Africa since the Last Glacial Maximum # Journal_Name: Quaternary Science Reviews # Volume: 174 # Edition: # Issue: # Pages: 54-62 # Report Number: # DOI: 10.1016/j.quascirev.2017.08.011 # Online_Resource: https://www.sciencedirect.com/science/article/pii/S0277379116306758 # Full_Citation: # Abstract: A fundamental and long-standing question of southern African palaeoclimatology is the way tropical and temperate climate system dynamics have influenced rainfall regimes across the subcontinent since the Last Glacial Maximum. In this paper, we analyse a selection of recently published palaeoclimate reconstructions along a southwest-northeast transect across South Africa. These records span the last 22,300 years, and encompass the transition between the region’s winter and summer rainfall zones. In synthesis, these records confirm broad elements of the dominant paradigm, which proposes an inverse coeval relationship between temperate and tropical systems, with increased precipitation in the winter (summer) rainfall zone during glacial (interglacial) periods. Revealed, however, is a substantially more complex dynamic, with millennial-scale climate change events being strongly – even predominantly – influenced by the interaction and combination of temperate and tropical systems. This synoptic forcing can create same sign anomalies across the South African rainfall zones, contrary to expectations based on the classic model of phase opposition. These findings suggest a new paradigm for the interpretation of southern African palaeoenvironmental records that moves beyond simple binary or additive influences of these systems. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: European Research Council # Grant: "HYRAX"; grant 258657 #--------------------------------------- # Funding_Agency # Funding_Agency_Name: The Leverhulme Trust # Grant: Fossilised Herbivore Middens: New Perspectives on SW African Climate Change #--------------------------------------- # Site Information # Site_Name: Seweweekspoort # Location: Africa>Southern Africa>South Africa # Country: South Africa # Northernmost_Latitude: -33.367 # Southernmost_Latitude: -33.367 # Easternmost_Longitude: 21.414 # Westernmost_Longitude: 21.414 # Elevation: 1090 #--------------------------------------- # Data_Collection # Collection_Name: SWP2017d15Ncomp # First_Year: 22281 # Last_Year: -43 # Time_Unit: cal yr BP # Core_Length: # Notes: #--------------------------------------- # Chronology_Information # Chronology: # # Labcode # depth_top # depth_bottom # mat.dated # 14C.raw # 14C.raw_err # datemeth # SWP-1-1 top # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth # UBA-16698 7.995 10.005 hyraceum 3067 32 14C AMS # UBA-18638 59.0196078 61.372549 hyraceum 4509 40 14C AMS # UBA-18639 89.117647 90.5882353 hyraceum 5322 35 14C AMS # UBA-18640 127.745098 129.9019608 hyraceum 6226 33 14C AMS # UBA-18641 145.9803921 152.6470588 hyraceum 8535 39 14C AMS # SWP-1-2a NaN NaN NaN NaN NaN NaN # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth # UBA-22927 11.14427132 14.73093335 hyraceum 10243 39 14C AMS # UBA-18645 35.99471541 42.91184931 hyraceum 13621 60 14C AMS # UBA-18646 72.88609631 79.93132531 hyraceum 17143 83 14C AMS # UBA-18647 112.72366391 117.71937171 hyraceum 18746 95 14C AMS # SWP-1-4b NaN NaN NaN NaN NaN NaN # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth # surface NaN NaN NaN -60 1 year of collection # UBA-19558 7.52537331 11.85504014 hyraceum -7 5 14C AMS # UBA-19559 45.66767635 48.14177169 hyraceum 975 27 14C AMS # UBA-22921 57.52271649 60.40916104 hyraceum 1543 25 14C AMS # UBA-22922 71.64567735 74.53212195 hyraceum 2238 25 14C AMS # UBA-19560 100.92247215 103.39656745 hyraceum 11138 47 14C AMS # UBA-22924 115.35469485 117.93187755 hyraceum 12190 41 14C AMS # UBA-19561 126.79738585 130.61161615 hyraceum 12626 55 14C AMS # UBA-22925 147.72410885 150.09511685 hyraceum 12618 46 14C AMS # UBA-19562 172.98049865 176.89781625 hyraceum 13425 67 14C AMS # SWP-1-5 NaN NaN NaN NaN NaN NaN # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth # UBA-19565 6.32641204 8.97942354 hyraceum 410 21 14C AMS # UBA-22742 23.5709868 26.2239983 hyraceum 1657 35 14C AMS # UBA-22743 49.79498511 52.3459577 hyraceum 3428 28 14C AMS # UBA-22744 72.95781629 75.61082778 hyraceum 4973 29 14C AMS # UBA-22745 97.65123108 100.40628148 hyraceum 6216 29 14C AMS # UBA-22746 122.95687918 125.81396848 hyraceum 7559 32 14C AMS # UBA-22747 148.16048848 151.01757778 hyraceum 8292 35 14C AMS # UBA-22748 173.16001998 175.60895358 hyraceum 8609 35 14C AMS # UBA-19566 197.75139578 200.20032948 hyraceum 9341 42 14C AMS # SWP-3-1 NaN NaN NaN NaN NaN NaN # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth # UBA-19320 5.631815 8.27532 hyraceum 3405 32 14C AMS # UBA-19321 54.134385 57.4675 hyraceum 3509 40 14C AMS # UBA-19322 105.855135 108.95838 hyraceum 4661 65 14C AMS # UBA-19323 159.29991 162.51809 hyraceum 5454 46 14C AMS # UBA-21381 177.114835 180.44795 hyraceum 6212 30 14C AMS # UBA-21382 199.52716 202.97521 hyraceum 7840 32 14C AMS # UBA-19324 216.30767 219.29598 hyraceum 9354 52 14C AMS # UBA-19325 265.844655 268.02842 hyraceum 10717 52 14C AMS # UBA-19326 326.300465 328.599165 hyraceum 12874 84 14C AMS # #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ## sample sample ID,hyraceum,,,,other collections,,,C, ## age_BP age,hyraceum,,calendar year before present,,other collections,,weighted mean for average sample depth,N, ## d15N_LOESS delta 15N,hyraceum,,per mil,,other collections,smoothed published composite d15N record,,N, Results of locally estimated scatterplot smoothing (LOESS) of combined delta 15N data sets as described in metadata ## d15N_LOESS_residual delta 15N,hyraceum,,per mil,,other collections,residual,,N,Residual of LOESS analysis used for estimation of confidence band ## d15N_LOESS_2.5_percentile delta 15N,hyraceum,upper 95% CI,per mil,,other collections,,,N,Bootstrap estimate of 95% confidence band ## d15N_LOESS_97.5_percentile delta 15N,hyraceum,lower 95% CI,per mil,,other collections,,,N,Bootstrap estimate of 95% confidence band # #------------------------ # Data # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Value: Please contact Principal Investigator Brian Chase to obtain these data