An organic geochemical approach to problems of glacial-interglacial climatic variability
type: CreativeWork
description: The concentration and carbon isotopic composition (δ13C) of sedimentary organic carbon (Corg), N/C ratios, and terrigenous and marine δ13C-Corg end-members form a basis from which to address problems of Late Quaternary glacial-interglacial climatic variability in a 208.7 m hydraulic piston core (DSDP 619) from the Pigmy Basin in the northern Gulf of Mexico. Paired analyses of δ13C-Corg and N/C are consistent with the hypothesis that the sedimentary organic carbon in the Pigmy Basin is a climatically-determined mixture of C3-photosynthetic terrigenous and marine organic matter, confirming the model of Sackett (1964). A high resolution (~1.4-2.7 ky/sample) δ13C-Corg record shows that sedimentary organic carbon in interglacial oxygen isotope (sub)stages 1 and 5a-b are enriched in 13C (average ± 10 values are -24.2 ± 1.2% 0 and -23.0 ± 0.8% relative to PDB, respectively) while glacial isotope stage values 2 are relatively depleted (-25.6 ± 0.5%). Concentrations of terrigenous and marine sedimentary organic carbon are calculated using δ13C-Corg and Corg measurements, and terrigenous and marine δ13C-Corg end-members. The net accumulation rate of terrigenous organic carbon is 3.7±3.1 times higher in isotope stages 2-4 than in (sub)stages 1 and 5a-b, recording higher erosion rates of terrigenous organic material in glacial periods than interglacial periods. The concentration and net accumulation rates of marine and terrigenous Corg suggest that the nutrient-bearing plume of the Mississippi River may have advanced and retreated across the Pigmy Basin as sea level fell and rose in response to glacial-interglacial sea level change. A study of selected organic biomarker compounds which could serve as tracers of terrigenous and marine sedimentary organic matter sources was performed by comparison with contemporaneous sedimentary organic carbon isotopic composition (δ13C-Corg). Organic carbon-normalized concentrations of total long chain (C37-C39) unsaturated alkenones and indivi…
abstract: The concentration and carbon isotopic composition (δ13C) of sedimentary organic carbon (Corg), N/C ratios, and terrigenous and marine δ13C-Corg end-members form a basis from which to address problems of Late Quaternary glacial-interglacial climatic variability in a 208.7 m hydraulic piston core (DSDP 619) from the Pigmy Basin in the northern Gulf of Mexico. Paired analyses of δ13C-Corg and N/C are consistent with the hypothesis that the sedimentary organic carbon in the Pigmy Basin is a climatically-determined mixture of C3-photosynthetic terrigenous and marine organic matter, confirming the model of Sackett (1964). A high resolution (~1.4-2.7 ky/sample) δ13C-Corg record shows that sedimentary organic carbon in interglacial oxygen isotope (sub)stages 1 and 5a-b are enriched in 13C (average ± 10 values are -24.2 ± 1.2% 0 and -23.0 ± 0.8% relative to PDB, respectively) while glacial isotope stage values 2 are relatively depleted (-25.6 ± 0.5%). Concentrations of terrigenous and marine sedimentary organic carbon are calculated using δ13C-Corg and Corg measurements, and terrigenous and marine δ13C-Corg end-members. The net accumulation rate of terrigenous organic carbon is 3.7±3.1 times higher in isotope stages 2-4 than in (sub)stages 1 and 5a-b, recording higher erosion rates of terrigenous organic material in glacial periods than interglacial periods. The concentration and net accumulation rates of marine and terrigenous Corg suggest that the nutrient-bearing plume of the Mississippi River may have advanced and retreated across the Pigmy Basin as sea level fell and rose in response to glacial-interglacial sea level change. A study of selected organic biomarker compounds which could serve as tracers of terrigenous and marine sedimentary organic matter sources was performed by comparison with contemporaneous sedimentary organic carbon isotopic composition (δ13C-Corg). Organic carbon-normalized concentrations of total long chain (C37-C39) unsaturated alkenones and indivi…
author: Jasper, John P.
language: en_US
keywords: Organic geochemistry, Paleoceanography
date published: 1988-05
date modified: 2026-07-27T22:05:18Z
provider: Woods Hole Oceanographic Institute
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1912/4626

PropertyValue
property ID: DOI
value: 10.1575/1912/4626