(Table 1) Geochemistry, accumulation rates and sea surface temperature estimation of ODP Site 138-846, supplement to: Emeis, Kay-Christian; Doose, Heidi; Mix, Alan C; Schulz-Bull, Detlef (1995): Alkenone sea-surface temperatures and carbon burial at Site 846 (eastern equatorial Pacific Ocean): the last 1.3 m.y. In: Pisias, NG; Mayer, LA; Janecek, TR; Palmer-Julson, A; van Andel, TH (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 138, 605-613

DOI

We analyzed the unsaturation ratio (Uk37) of long-chain ketones - a molecular sea-surface temperature (SST) indicator û concentrations of carbonate and organic carbon in sediments from Site 846 in the eastern equatorial Pacific Ocean. Based on an isotopic age model for the composite depth section of 0-46 m below seafloor and on estimates of sediment density, accumulation rates of these biogenic compounds were calculated. Our combined temperature and biogenic flux record traces conditions at the origin of the South Equatorial Current over the last 1.3 m.y.SSTs have fluctuated considerably over the interval studied. A long trend of gradual decrease from 24°C at 1.3 Ma ends between 500 and 400 Ka, when lowest values of 19°C were reached. Since this time, the temperature data indicate a warming trend to the Holocene modulated by high-amplitude variation (19° to 27°C). The inversion of the trend between 400 and 500 Ka coincides with maximal accumulation rates of carbonate, which since then have decreased. In contrast, organic carbon accumulation since then has increased in variability and in absolute values.On shorter time scales, the records show a strong link to the global climatic background. Since 1.3 Ma, carbonate (0.2-3 g/cm2/k.y.) and organic carbon accumulation rates (2-30 mg/cm2/k.y.) were consistently high (more than twice their modern values and those of interglacials) during glacial maxima in the benthic isotope record, when temperatures were low.However, cross-spectral analyses with the d18O record suggest that variation in organic carbon flux is not linked directly to variations in SST. Temperature maxima in our record led interglacial events by 7 k.y. in the 100-k.y. eccentricity cycle and by 5 k.y. in the 41-k.y. obliquity cycle. In contrast, maxima in organic carbon accumulation lag behind glacial maxima and low temperatures by 14 k.y. in the eccentricity cycle. On glacial/interglacial time scales, a prominent influence on SST - but not on organic carbon burial - at Site 846 appears to be the advection of cold water into the South Equatorial Current.

DEPTH, sediment is given in mbsf, ages after Mix et al. (1995, doi:10.2973/odp.proc.sr.138.160.1995)

Identifier
DOI https://doi.org/10.1594/PANGAEA.807824
Related Identifier https://doi.org/10.2973/odp.proc.sr.138.131.1995
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.807824
Provenance
Creator Emeis, Kay-Christian; Doose, Heidi; Mix, Alan C; Schulz-Bull, Detlef
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1995
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 3062 data points
Discipline Earth System Research
Spatial Coverage (-90.818 LON, -3.095 LAT); South Pacific Ocean
Temporal Coverage Begin 1991-05-21T00:00:00Z
Temporal Coverage End 1991-05-26T00:00:00Z