{"NOAAStudyId":"14268","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":"2013-04-01","dataPublisher":"NOAA","dataType":"SPELEOTHEMS","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/speleothem","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-cave-14268.xml","doi":null,"earliestYearBP":5,"earliestYearCE":1945,"entryId":"noaa-cave-14268","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"0002193"}],"investigators":"Sletten, H.R.; Railsback, L.B.; Liang, F.; Brook, G.A.; Marais, E.; Hardt, B.F.; Cheng, H.; Edwards, L.","mostRecentYearBP":0,"mostRecentYearCE":1950,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/14268","originalSource":null,"publication":[{"abstract":"Stalagmite DP1, a speleothem 1.6 m in length from Dante Cave in northeastern Namibia, provides a paleoclimate record of a gradual transition from wetter to drier conditions from 4.6 to 3.3 ka BP, a variable but pronounced dry period from 3.3 to 1.8 ka, and a wetter but variable period from 1.8 ka to the present. This record is based on 30 U/Th radiometric dates and their resulting calculated growth rates, and on C and O stable isotope data, relative proportions of aragonite and calcite in layers, measurements of stalagmite width along layers, and observation of petrographic surfaces suggestive of changes from drier to wetter conditions and vice versa. The stalagmite's first deposition, which seemingly followed conditions too wet for deposition, coincided with desiccation in the Sahara and the end of the African Humid Period there. Gradual drying continued and led to a sustained very dry period from 3322 ± 11 to 1786 ± 10 BP, a \"2-3 ka BP Dry Period\". That dry period began and ended abruptly. The abrupt transition from drier to wetter conditions at 1.8 ka coincides with the beginning of the Iron Age in southern Africa, suggesting that wetter conditions facilitated migrations and/or changes in food production that may have contributed to a transition in human technologies and lifestyles. This transition is coeval with transitions to colder conditions in ice core records from Greenland and Antarctica. The DP1 record suggests considerable change over the past 1800 years, with at least three wet/dry cycles. The wettest conditions may have occurred relatively recently, between 230 and 100 BP (A.D. 1720 and 1850), so that early European explorers may have seen and/or heard reports of conditions among the wettest during the later Holocene in southern Africa.","author":null,"citation":"Hillary R. Sletten, L. Bruce Railsback, Fuyuan Liang, George A. Brook, Eugene Marais, Benjamin F. Hardt, Hai Cheng, R. Lawrence Edwards. 2013. A petrographic and geochemical record of climate change over the last 4600 years from a northern Namibia stalagmite, with evidence of abruptly wetter climate at the beginning of southern Africa's Iron Age, Palaeogeography, Palaeoclimatology, Palaeoecology, Palaeogeography, Palaeoclimatology, Vol. 376, pp. 149-162. DOI: 10.1016/j.palaeo.2013.02.030","edition":null,"identifier":{"id":"10.1016/j.palaeo.2013.02.030","type":"doi","url":"http://dx.doi.org/10.1016/j.palaeo.2013.02.030"},"issue":null,"journal":"Palaeogeography, Palaeoclimatology, Palaeoecology","pages":null,"pubRank":"1","pubYear":2013,"reportNumber":null,"title":"A petrographic and geochemical record of climate change over the last 4600 years from a northern Namibia stalagmite, with evidence of abruptly wetter climate at the beginning of southern Africa's Iron","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["drought","hydrology"],"site":[{"NOAASiteId":"54752","geo":{"geoType":"Feature","geometry":{"coordinates":["-19.4","17.883333"],"type":"POINT"},"properties":{"easternmostLongitude":"17.883333","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"-19.4","southernmostLatitude":"-19.4","westernmostLongitude":"17.883333"}},"locationName":"Continent>Africa>Southern Africa>Namibia","mappable":"Y","paleoData":[{"NOAADataTableId":"24259","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>speleothems>geochemistry","earth science>paleoclimate>speleothems>carbon isotopes","earth science>paleoclimate>speleothems>oxygen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/dantecave2013sletten.txt","linkText":"dantecave2013sletten.txt","urlDescription":"Speleothem","variables":[{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"millimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":"raw","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":"raw","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 18O"},{"cvAdditionalInfo":"corrected for aragonite","cvDataType":"SPELEOTHEMS","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for aragonite","cvDataType":"SPELEOTHEMS","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 18O"},{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":"raw","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"percent","cvWhat":"geological material>identified mineral>carbonate>calcium carbonate>calcite"},{"cvAdditionalInfo":null,"cvDataType":"SPELEOTHEMS","cvDetail":"raw","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>identified mineral>carbonate>calcium carbonate","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"millimeter per year","cvWhat":"formation property>formation rate>growth rate"}]}],"dataTableName":"Dante","dataTableNotes":"Dante Cave (19° 24′ S; 17° 53′ E) Otjozondjupa Region, Namibia.\r\nDescription of each variable follows(refer to Variable section for corresponding short name): \r\ndepth_mm - Distance from top of stalagmite.\r\nage_calyrBP - Age as determined using relationships illustrated in Figure 8 and dates reported in Table 1 of Sletten et al.\r\ncalcite% - Porportion of layer that is calcite. \"0\" indicates a layer entirely of aragonite. (Data are shown only where layering was sufficiently obvious to allow a determination)\r\nd13CcarbVPDB - Untransformed carbon isotope data.\r\nd18OcarbVPDB - Untransformed oxygen isotope data.\t\r\nd13CcarbVPDB_ac\t- Same as d13CcarbVPDB, but with 1.7 substracted for data from aragonite to convert data to a calcite basis (to eliminate the effect of fractionation between aragonite and calcite.)\r\nd18OcarbVPDB_ac\t- Same as d18OcarbVPDB, but with 0.8 substracted for data from aragonite to convert data to a calcite basis (to eliminate the effect of fractionation between aragonite and calcite.)\r\ngrowth_mmyr - Growth rate.  Results are not shown at the position of a radiometric date because a rate canot be calculated there.\t\r\nnotes - identification of stable isotope sample; and mineralogy at crest of stalagmite, where stable isotope sample was taken.\r\nKeywords - hydrology, drought, carbon isotopes, and oxygen isotopes, geochemistry","earliestYear":5,"earliestYearBP":5,"earliestYearCE":1945,"mostRecentYear":0,"mostRecentYearBP":0,"mostRecentYearCE":1950,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Dante Cave"}],"studyCode":null,"studyName":"Dante Cave, Namibia, Holocene Stalagmite Stable Isotope and Mineralogy Data","studyNotes":null,"version":"1.0","xmlId":"12269"}