Open AccessUnmixing of stable isotope signals using single specimen δ 18 O analyses
Author(s) -
Wit J.C.,
Reichart G.J.,
Ganssen G.M.
Publication year - 2013
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/ggge.20101
Subject(s) - bioturbation , geology , foraminifera , sediment , sedimentation , stable isotope ratio , sampling (signal processing) , series (stratigraphy) , oceanography , isotope , paleontology , benthic zone , physics , filter (signal processing) , quantum mechanics , computer science , computer vision
The resolution at which foraminiferal stable isotopes are applied in paleo‐environmental studies is ever increasing, resulting in continuous sampling of sediment cores. The resolution of such continuously sampled records depends on the rate of sedimentation of foraminiferal shells in its relation to the intensity of bioturbation. Bioturbation essentially mixes sediment layers of different age, altering the primary climate signal, thereby impacting the accuracy of both the timing and magnitude of reconstructed climate changes. A new approach to assess and correct the impact of bioturbation is investigated here, based on the δ 18 O of individual specimens of planktonic foraminifera Globorotalia inflata from a series of boxcore samples in the Eastern North Atlantic. Average δ 18 O values decrease southward from 1.62 to 1.07‰ with the exception of site T86‐11 (1.35‰). The δ 18 O distribution of each station can be fitted with a uni‐ to polymodal distribution. A nonunimodal distribution strongly suggests admixing of bioturbated individuals. Quantification of these distributions allows deconvolving the original and bioturbated signals and subsequently provides a correction for bioturbation.