Timescales of lateral sediment transport in the Panama Basin as revealed by radiocarbon ages of alkenones, total organic carbon and foraminifera
Eglinton, Timothy I.
Mix, Alan C.
MetadataShow full item record
KeywordCompound-specific radiocarbon dating; Alkenones; Lateral sediment transport; Panama Basin; Eastern Equatorial Pacific
Paired radiocarbon measurements on haptophyte biomarkers (alkenones) and on cooccurring tests of planktic foraminifera (Neogloboquadrina dutertrei and Globogerinoides sacculifer) from late glacial to Holocene sediments at core locations ME0005-24JC, Y69- 71P, and MC16 from the south-western and central Panama Basin indicate no significant addition of pre-aged alkenones by lateral advection. The strong temporal correspondence between alkenones, foraminifera and total organic carbon (TOC) also implies negligible contributions of aged terrigenous material. Considering controversial evidence for sediment redistribution in previous studies of these sites, our data imply that the laterally supplied material cannot stem from remobilization of substantially aged sediments. Transport, if any, requires syn-depositional nepheloid layer transport and redistribution of low-density or fine-grained components within decades of particle formation. Such rapid and local transport minimizes the potential for temporal decoupling of proxies residing in different grain size fractions and thus facilitates comparison of various proxies for paleoceanographic reconstructions in this study area. Anomalously old foraminiferal tests from a glacial depth interval of core Y69-71P may result from episodic spillover of fast bottom currents across the Carnegie Ridge transporting foraminiferal sands towards the north.
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 290 (2010): 340-350, doi:10.1016/j.epsl.2009.12.030.
Showing items related by title, author, creator and subject.
Ohkouchi, Naohiko; Xu, Li; Reddy, Christopher M.; Montlucon, Daniel B.; Eglinton, Timothy I. (Dept. of Geosciences, University of Arizona, 2005)The chemical and isotopic compositions of long-chain (C36–C39) unsaturated ketones (alkenones), a unique class of algal lipids, encode surface ocean properties useful for paleoceanographic reconstruction. Recently, we ...
Radiocarbon dating of alkenones from marine sediments : III. Influence of solvent extraction procedures on 14C measurements of foraminifera Ohkouchi, Naohiko; Eglinton, Timothy I.; Hughen, Konrad A.; Roosen, Ellen; Keigwin, Lloyd D. (Dept. of Geosciences, University of Arizona, 2005)As a result of the growing use of multiple geochemical proxies to reconstruct ocean and climate changes in the past, there is an increasing need to establish temporal relationships between proxies derived from the same ...
Mollenhauer, Gesine; Montlucon, Daniel B.; Eglinton, Timothy I. (Dept. of Geosciences, University of Arizona, 2005)We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to ...