{"NOAAStudyId":"8698","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2009-08-01","dataPublisher":"NOAA","dataType":"OTHER COLLECTIONS","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/other-collections","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-other-8698.xml","doi":null,"earliestYearBP":11724,"earliestYearCE":-9774,"entryId":"noaa-other-8698","funding":[{"fundingAgency":"Leverhulme Trust","fundingGrant":null}],"investigators":"Chase, B.M.; Meadows, M.E.; Scott, L.; Thomas, D.S.G.; Marais, E.; Sealy, J.; Reimer, P.J.","mostRecentYearBP":-27,"mostRecentYearCE":1977,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/8698","originalSource":null,"publication":[{"abstract":"The discovery of sensitive paleoenvironmental proxies contained \r\nwithin fossilized rock hyrax middens from the margin of the central \r\nNamib Desert, Africa, is providing unprecedented insight into the \r\nregion's environmental history. High-resolution stable carbon and\r\nnitrogen isotope records spanning 0-11,700 cal (calibrated) yr B.P. \r\nindicate phases of relatively humid conditions from 8700-7500, \r\n6900-6700, 5600-4900, and 4200-3500 cal yr B.P., with a period of \r\nmarked aridity occurring from 3500 until ca. 300 cal yr B.P. \r\nTransitions between these phases appear to have occurred very rapidly, \r\noften within <200 years. Of particular importance are: \r\n(1) the observed relationship between regional aridification and \r\nthe decline in Northern Hemisphere insolation across the Holocene, \r\nand (2) the significance of suborbital scale variations in climate \r\nthat covary strongly with fluctuations in solar forcing.\r\nTogether, these elements call for a fundamental reexamination of \r\nthe role of orbital forcing on tropical African systems, and a \r\nreconsideration of what factors drive climate change in the region. \r\nThe quality and resolution of these data far surpass any other \r\nevidence available from the region, and the continued development \r\nof this unique archive promises to revolutionize paleoenvironmental \r\nstudies in southern Africa.\r\n","author":null,"citation":"Chase, B.M., M.E. Meadows, L. Scott, D.S.G. Thomas, E. Marais, \r\nJ. Sealy, and P.J. Reimer.  2009. \r\nA record of rapid Holocene climate change preserved in hyrax \r\nmiddens from southwestern Africa. \r\nGeology, Vol. 37, No. 8, pp. 703-706, August 2009. \r\ndoi: 10.1130/G30053A.1.  \r\n\r\n","edition":null,"identifier":{"id":"10.1130/G30053A.1","type":"doi","url":"http://dx.doi.org/10.1130/G30053A.1"},"issue":null,"journal":"Geology","pages":null,"pubRank":"1","pubYear":2009,"reportNumber":null,"title":"A record of rapid Holocene climate change preserved in hyrax  middens from southwestern Africa. ","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["PAGES Africa 2k","PAGES 2k Network"],"site":[{"NOAASiteId":"52863","geo":{"geoType":"Feature","geometry":{"coordinates":["-21.8317","15.1955"],"type":"POINT"},"properties":{"easternmostLongitude":"15.1955","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"-21.8317","southernmostLatitude":"-21.8317","westernmostLongitude":"15.1955"}},"locationName":"Continent>Africa>Southern Africa>Namibia","mappable":"Y","paleoData":[{"NOAADataTableId":"21022","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>others"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/midden/africa/spitzkoppe2009iso.txt","linkText":"spitzkoppe2009iso.txt","urlDescription":"Data","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>others"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/midden/africa/spitzkoppe2009iso.xls","linkText":"spitzkoppe2009iso.xls","urlDescription":"Data","variables":[]}],"dataTableName":"SPZ1","dataTableNotes":null,"earliestYear":11724,"earliestYearBP":11724,"earliestYearCE":-9774,"mostRecentYear":-27,"mostRecentYearBP":-27,"mostRecentYearCE":1977,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Klein Spitzkoppe"}],"studyCode":null,"studyName":"Chase et al. 2009 SW Africa Rock Hyrax Midden Isotope Data","studyNotes":"Stable isotope data (d13C and d15N) from three Rock Hyrax middens on the \nsouth-facing flank of Klein Spitzkoppe, western-central Namibia, Southern \nAfrica (21.8317°S, 15.1955°E). \n\nThe d13C values vary between -23.4 per mil and -17.0 per mil (Figure 2). \nAs a representation of hyrax diet, these variations primarily reflect \nthe proportion of C3 plants (in this environment, generally trees and shrubs) \nversus C4 plants (generally grasses) with average d13C value of ~-26 per mil \nand ~-12per mil respectively (Codron et al., 2007; Smith and Epstein, 1971). \nObservations indicate that hyraxes consume an exceptionally wide range of \nplants (as many as 79 species of grass, shrubs, and trees), but prefer grasses \nto the leaves and bark of trees and shrubs (Hoeck, 1975). In xeric savannah \nregions such as at Spitzkoppe, however, the latter become an important part \nof their diet during dry periods when grass is scarce (Hoeck, 1975). \nConsidering this, it is expected that during times of less or less regular \nrains d13C values would become relatively lower as hyraxes come to depend \nincreasingly on the arboreal taxa that can access reserves of groundwater \n(Walker et al., 1981).  Overall, the d13C records obtained from these middens \nsuggest that marked seasonality has been a part of the region's rainfall regime \nthroughout the Holocene, with C3 plants consistently constituting a significant \npart of the animals' diet.\n\nThe d15N values vary from 13.4 to 7.4 per mil. The potential of nitrogen \nstable isotope compositions as a climatic indicator has long been recognised, \nbut studies of modern ecosystems have produced complex data sets, that have \nproved difficult to interpret (e.g. Heaton, 1987; Heaton et al., 1986). \nAmong herbivores, 15N abundance in animal tissues is strongly influenced by \nclimate, diet and/or physiology (Ambrose and DeNiro, 1986; Heaton et al., 1986). \nWhile early studies focused on the possible effects that animal metabolism \nwould have on the signal (Ambrose and DeNiro, 1986), subsequent studies of \nd15N values in plants across aridity gradients have indicated that it may not \nbe necessary to look towards herbivore metabolism for the link between d15N \nvalues and rainfall, as clear correlations are identified between higher d15N \nvalues and decreased rainfall in both C3 and C4 plants (Heaton, 1987; \nMurphy and Bowman, 2006; Swap et al., 2004) and soils (Aranibar et al., 2004). \nMurphy and Bowman's (2006) spatially-extensive studies of d15N values in both \ngrass and kangaroo bone from across Australia reveal a remarkably consistent \nrelationship between plant and bone d15N signals, suggesting that water \navailability, through its influence on the isotopic signature of plants/diet, \nis the primary control on animal d15N with metabolism having no clear effect.\n","version":"1.0","xmlId":"2914"}