{"NOAAStudyId":"13677","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":"2013-01-18","dataPublisher":"NOAA","dataType":"PALEOCEANOGRAPHY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/paleoceanography","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-ocean-13677.xml","doi":null,"earliestYearBP":11460000,"earliestYearCE":-11458050,"entryId":"noaa-ocean-13677","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"HOMINID Grant 0218511"}],"investigators":"Feakins, S.J.; Levin, N.E.; Liddy, H.M.; Sieracki, A.; Eglinton, T.I.; Bonnefille, R.","mostRecentYearBP":60000,"mostRecentYearCE":-58050,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/13677","originalSource":null,"publication":[{"abstract":"Intense debate surrounds the evolution of grasses using the C4 \r\n(Hatch-Slack) photosynthesis pathway and the emergence of African \r\ngrasslands, often assumed to be one and the same. Here, we bring \r\nnew insights with the combination of  plant leaf wax carbon isotopic \r\ncomposition (d13Cwax) and pollen data from marine sediments of the \r\nGulf of Aden (northeast Africa), which show that C4 biomass increases \r\nwere not necessarily associated with regional grassland expansion. \r\nWe find broadly opposing trends toward more enriched d13Cwax values \r\nand decreased grass pollen proportions between 12 and 1.4 Ma. \r\nThis apparently contradictory evidence can be reconciled if a greater \r\nproportion of the Late Miocene northeast African landscape were \r\ncovered by C3 grasses than previously thought, such that C4 grasses \r\nand shrubs replaced a C3 ecosystem including trees and productive \r\ngrasslands. In addition, d13Cwax and pollen both indicate that true \r\nrainforests were unlikely to have been extensive in northeast Africa \r\nat any time in the last 12 m.y., although seasonally dry forests \r\nwere a significant component of the regional landscape since the Late \r\nMiocene. Here, we extend regionally integrative marine archives \r\nof terrestrial vegetation back to 12 Ma, and we evaluate them in \r\nthe context of an updated compilation of pedogenic carbonate d13C \r\nvalues from East African Rift strata. We identify two distinct \r\nphases of increasing C4 biomass between 11 and 9 Ma (with a \r\nreversal by 4.3 Ma) and then a re-expansion between 4.3 and 1.4 Ma; \r\nsurprisingly, neither was associated with grassland expansion. \r\n","author":null,"citation":"Feakins, S.J., N.E. Levin, H.M. Liddy, A. Sieracki, \r\nT.I. Eglinton, and R. Bonnefille. 2013. \r\nNortheast African vegetation change over 12 million years. \r\nGeology, Published online January 17, 2013.\r\ndoi: 10.1130/G33845.1 ","edition":null,"identifier":{"id":"10.1130/G33845.1","type":"doi","url":"http://dx.doi.org/10.1130/G33845.1"},"issue":null,"journal":"Geology","pages":null,"pubRank":"1","pubYear":2013,"reportNumber":null,"title":"Northeast African vegetation change over 12 million years","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["biogeography"],"site":[{"NOAASiteId":"54324","geo":{"geoType":"Feature","geometry":{"coordinates":["11.89","48.25"],"type":"POINT"},"properties":{"easternmostLongitude":"48.25","maxElevationMeters":"-2152","minElevationMeters":"-2152","northernmostLatitude":"11.89","southernmostLatitude":"11.89","westernmostLongitude":"48.25"}},"locationName":"Ocean>Indian Ocean>Arabian Sea","mappable":"Y","paleoData":[{"NOAADataTableId":"23358","coreLengthMeters":482,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>population abundance","earth science>paleoclimate>paleocean>carbon isotopes","earth science>paleoclimate>paleocean>biomarkers"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/feakins2013/feakins2013.txt","linkText":"feakins2013.txt","urlDescription":"Original Data and Full Metadata","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>paleocean>biomarkers","earth science>paleoclimate>paleocean>carbon isotopes","earth science>paleoclimate>paleocean>population abundance"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/feakins2013/feakins2013.xls","linkText":"feakins2013.xls","urlDescription":"Original Data and Full Metadata","variables":[]}],"dataTableName":"DSDP231-2013","dataTableNotes":null,"earliestYear":11460000,"earliestYearBP":11460000,"earliestYearCE":-11458050,"mostRecentYear":60000,"mostRecentYearBP":60000,"mostRecentYearCE":-58050,"species":[],"timeUnit":"cal yr BP"}],"siteName":"DSDP 231"}],"studyCode":null,"studyName":"Gulf of Aden DSDP231 12Ma Pollen and d13Cwax Data","studyNotes":"Plant leaf wax carbon isotopic composition (d13Cwax) data \nand pollen counts from marine sediments collected at Deep \nSea Drilling Program (DSDP) site 231, Gulf of Aden, Africa. \nAge model from tephra and nannofossils datums correlated \nto dated records elsewhere. Vegetation evidence from pollen \nassemblage counts, as well as carbon isotopic composition \nof plant leaf waxes.  Pollen and leaf wax d13C are used \nto reconstruct the history of grasslands and C4 grasslands \nin NE Africa during the last 11.46 million years. ","version":"1.0","xmlId":"11699"}