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deMenocal, Peter B (1993): Stable isotopes, CaCO3, opal and terrigeneous of ODP Site 108-663 (Table A1) [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.208129, Supplement to: deMenocal, Peter B; Ruddiman, William F; Pokras, Edward M (1993): Influences of high- and low-latitude processes on African terrestrial climate: Pleistocene eolian records from equatorial Atlantic Ocean Drilling Program Site 663. Paleoceanography, 8(2), 209-242, https://doi.org/10.1029/93PA02688

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Abstract:
High- and low-latitude forcing of terrestrial African paleoclimate variability is demonstrated using 900 ka eolian and biogenic component records from Ocean Drilling Program site 663 in the eastern equatorial Atlantic. Terrigenous (eolian dust) and phytolith (savannah grass cuticle) accumulation rate records vary predominantly at 100 and 41 kyr periodicities and spectral phase estimates implicate high-latitude forcing. The abundance of freshwater diatoms (Melosira) transported from dry African lake beds varies coherently at 23-19 kyr orbital periodicities and at a phasing which implicates low-latitude precessional monsoon forcing. Modeling studies demonstrate that African climate is sensitive to both high- and low-latitude boundary conditions. African monsoon intensity is modulated by direct insolation variations due to orbital precession, whereas remote high-latitude forcing can be related to cool North Atlantic sea surface temperatures (SSTs) which promote African aridity and enhance dust-transporting wind speeds. The site 663 terrigenous and phytolith records covary with North Atlantic SST variability at 41 °N (site 607). We suggest that Pleistocene African climate has responded to both high-latitude North Atlantic SST variability as well as low-latitude precessional monsoon forcing; the high-latitude influence dominates the sedimentary record. Prior to circa 2.4 Ma, terrigenous variations occurred primarily at precessional periodicities (23-19 kyr), indicating that African climate was largely controlled by low-latitude insolation variations prior to the onset of high-amplitude glacial-interglacial climate change.
Project(s):
Coverage:
Latitude: -1.197800 * Longitude: -11.878500
Date/Time Start: 1986-03-26T00:00:00 * Date/Time End: 1986-03-28T00:00:00
Minimum Elevation: -3706.0 m * Maximum Elevation: -3706.0 m
Event(s):
108-663 * Latitude: -1.197800 * Longitude: -11.878500 * Date/Time Start: 1986-03-26T00:00:00 * Date/Time End: 1986-03-28T00:00:00 * Elevation: -3706.0 m * Penetration: 299.2 m * Recovery: 272.6 m * Location: South Atlantic Ocean * Campaign: Leg108 * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 32 cores; 299.2 m cored; 0 m drilled; 91.1% recovery
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1AGEAgeka BPGeocode
2Depth, compositeDepth compmcddeMenocal, Peter BIntercore correlation
3Sample code/labelSample labeldeMenocal, Peter BDSDP/ODP/IODP sample designation
4Sedimentation rateSRcm/kadeMenocal, Peter B
5Globigerinoides ruber white, δ18OG. ruber w δ18O‰ PDBdeMenocal, Peter B
6Calcium carbonateCaCO3%deMenocal, Peter B
7Opal, biogenic silicabSiO2%deMenocal, Peter B
8TerrigenousTerr%deMenocal, Peter B
9Density, dry bulkDBDg/cm3deMenocal, Peter B
10MelosiraMelosira10000#/gdeMenocal, Peter B
11PhytolithsPhytoliths10000#/gdeMenocal, Peter B
Size:
3372 data points

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