Stratigraphy in the Greenland/ Iceland/Norwegian (GIN) seas: A multiproxy approach on Pleistocene sediments
Langue
EN
Chapitre d'ouvrage
Ce document a été publié dans
Stratigraphy & Timescales. 2022, vol. 7, p. 37-80
Elsevier
Résumé en anglais
A multiproxy sedimentological study was conducted on five sediment cores retrieved between 67 and 79°N in the Greenland/Iceland/Norwegian seas in order to infer a common chronostratigraphic model for the selected cores. ...Lire la suite >
A multiproxy sedimentological study was conducted on five sediment cores retrieved between 67 and 79°N in the Greenland/Iceland/Norwegian seas in order to infer a common chronostratigraphic model for the selected cores. This model is based on the use of a series of geochemical, physical and micropaleontological proxies which are routinely measured in sedimentological investigations of marine sediment cores: the major and minor element content derived from X-Ray Fluorescence (XRF) core scanner analyses; the lightness and color of the sediment derived from spectrophotometry analyses; the magnetic susceptibility of the sediment; the distribution of planktonic foraminiferal assemblages combined to coccolith stratigraphy (acme zones) providing preliminary stratigraphic tie points. All those proxies are correlated independently between the five sediment cores. Our results demonstrate that high resolution studies using those standard paleoceanographical tools are powerful for establishing core-to-core correlation. A chronostratigraphical framework is proposed based on the correlation of the planktonic δ18O isotopic record obtained in core M17KC03 with the LR04 benthic δ18O reference stack. A comparison between the M17KC03 stratigraphy and other dated cores from the sub-polar North Atlantic confirms the robustness of the approach. Our study suggests that XRF core scanner-derived elemental ratios (especially those related to Ca), the lightness L* and the coccolith-based biostratigraphy provide robust stratigraphic tie-points at the scale of the whole Greenland/Iceland/Norwegian seas. The elemental ratio Sr/sum, the magnetic susceptibility, and planktonic foraminiferal records have a more local stratigraphic significance in the GIN seas. Over the last 1100 ka BP, our datasets are indicative of: (1) an excursion of Ca content and planktonic foraminiferal abundances during MIS 11, (2) an overall decrease toward present of both the detrital content (with the exception of values characterizing MIS 12) and of the magnetic susceptibility of sediments deposited during Glacials.< Réduire
Mots clés en anglais
Glacial sediments
Multiproxy stratigraphy
Nordic seas
Pleistocene