Accumulation rates of plant-wax-derived long-chain C25 to C35 odd-numbered n-alkanes and δ¹³C values of the n-C31 alkane of ODP Hole 175-1077B

• Main Authors: Schefuß, Enno, Schouten, Stefan, Jansen, J H Fred, Sinninghe Damsté, Jaap S
• Format: Dataset
• Language: English
• Published: PANGAEA 2004
• Subjects: 175-1077B; Accumulation rate; mass; AGE; Benguela Current; South Atlantic Ocean; Calculated; see reference(s); Carbon Preference Index; n-Alkanes (C25-C33); Depth; composite; sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Gas chromatography - Mass spectrometry (GC-MS); GeoB; Geosciences; University of Bremen; Intercore correlation; Joides Resolution; Leg175; n-Alkane; average chain length; C31/(C29+C31) ratio; n-Alkane C25-C35; flux; n-Alkane C29; δ13C; n-Alkane C31; n-Alkane C4 plant; reference to C29; reference to C31; Ocean Drilling Program; ODP; Sample code/label; Sum n-alkanes C25-C35; Sum odd numbered n-alkanes C25-C35
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.139752; https://doi.org/10.1594/PANGAEA.139752

The dominant forcing factors for past large-scale changes in vegetation are widely debated. Changes in the distribution of C4 plants-adapted to warm, dry conditions and low atmospheric CO2 concentrations (Collatz et al., 1998, doi:10.1007/s004420050468) -have been attributed to marked changes in environmental conditions, but the relative impacts of changes in aridity, temperature (Pagani et al., 1999, doi:10.1126/science.285.5429.876; Huang et al., 2001, doi:10.1126/science.1060143) and CO2 concentration (Cerling et al., 1993, doi:10.1038/361344a0; Kuypers et al., 1999, doi:10.1038/20659) are not well understood. Here, we present a record of African C4 plant abundance between 1.2 and 0.45 million years ago, derived from compound-specific carbon isotope analyses of wind-transported terrigenous plant waxes. We find that large-scale changes in African vegetation are linked closely to sea surface temperatures in the tropical Atlantic Ocean. We conclude that, in the mid-Pleistocene, changes in atmospheric moisture content - driven by tropical sea surface temperature changes and the strength of the African monsoon - controlled aridity on the African continent, and hence large-scale vegetation changes.