Santonian deep sea benthic foraminifera from IODP Site U1513, Mentelle Basin (SW Australia): Reactions of benthic foraminiferal assemblages to surface water cooling at southern high latitudes

Autor(en)
erik wolfgring, Maria Rose Petrizzo, Kenneth G. MacLeod, Brian T. Huber, David K. Watkins
Abstrakt

International Ocean Discovery Program (IODP) Expedition 369 recovered a stratigraphically complete, Santonian-aged, pelagic sedimentary sequence at Site U1513 on the Naturaliste Plateau (33°47.6084′S, 112°29.1338′E) at ~2800 m water depth. The site was located at ~60°S paleolatitude in Cretaceous times. A total of 59 samples studied from Holes 1513A and 1513B yielded 140 calcareous and nine agglutinated benthic foraminiferal taxa. Gavelinellids (Notoplanulina, Gavelinella, Anomalinoides) and Gyroidinoides spp., are the most abundant taxa overall and also dominate most samples. We also report 382 foraminiferal stable isotopic measurements and infer cooling [of ~5 °C in surface waters and 2 °C at the seafloor] based on changes in δ

18O values for benthic and planktonic taxa through the Santonian at Site U1513. Inferred cooling was accompanied by changes in planktonic and benthic foraminiferal assemblages. At Site U1513, benthic foraminiferal taxonomic richness declines by 15 species (from 20– 25 to 5–10 taxa) towards the upper Santonian. Within this interval, epifaunal, oxic foraminifera diminish in absolute and relative abundance, and there is a parallel relative increase in opportunistic taxa and infaunal foraminifera. Changes in benthic foraminiferal communities indicate a shift from oligotrophic to eutrophic conditions in the bottom water despite the general cooling trend. This paper explores the causes and effects of the paleoenvironmental changes in the bottom waters.

Organisation(en)
Institut für Paläontologie
Externe Organisation(en)
Università degli Studi di Milano-Bicocca, University of Missouri-Columbia, Smithsonian Institution, University of Nebraska-Lincoln
Journal
Marine Micropaleontology
Band
175
ISSN
0377-8398
DOI
https://doi.org/10.1016/j.marmicro.2022.102152
Publikationsdatum
08-2022
Peer-reviewed
Ja
ÖFOS 2012
105107 Geoelektrik
Schlagwörter
ASJC Scopus Sachgebiete
Oceanography, Palaeontology
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/497e70ef-050c-4c2f-8b64-1a78a2c5b25b