Planktonic foraminiferal response to the latest Maastrichtian abrupt warm event; a case study from South Atlantic DSDP Site 525A

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doi: 10.1016/S0377-8398(03)00021-5
Author(s): Abramovich, Sigal; Keller, Gerta
Author Affiliation(s): Primary:
Princeton University, Department of Geosciences, Princeton, NJ, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 48(3-4), p.225-249. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. Includes appendices. 47 refs.; illus.
Summary: An abrupt global warming of 3-4°C occurred near the end of the Maastrichtian at 65.45-65.10 Ma. The environmental effects of this warm event are here documented based on stable isotopes and quantitative analysis of planktonic foraminifera at the South Atlantic DSDP Site 525A. Stable isotopes of individual species mark a rapid increase in temperature and a reduction in the vertical water mass stratification that is accompanied by a decrease in niche habitats, reduced species diversity and/or abundance, smaller species morphologies or dwarfing, and reduced photosymbiotic activity. During the warm event, the relative abundance of a large number of species decreased, including tropical-subtropical affiliated species, whereas typical mid-latitude species retained high abundances. This indicates that climate warming did not create favorable conditions for all tropical-subtropical species at mid-latitudes and did not cause a massive retreat in the local mid-latitude population. A noticeable exception is the ecological generalist Heterohelix dentata Stenestad that dominated during the cool intervals, but significantly decreased during the warm event. However, dwarfing is the most striking response to the abrupt warming and occurred in various species of different morphologies and lineages (e.g. biserial, trochospiral, keeled globotruncanids). Dwarfing is a typical reaction to environmental stress conditions and was likely the result of increased reproduction rates. Similarly, photosymbiotic activity appears to have been reduced significantly during the maximum warming, as indicated by decreased δ13C values. The foraminiferal response to climate change is thus multifaceted resulting in decreased species diversity, decreased species populations, increased competition due to reduced niche habitats, dwarfing and reduced photosymbiotic activity. Abstract Copyright (2003) Elsevier, B.V.
Year of Publication: 2003
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Biodiversity; Biogeography; C-13/C-12; Carbon; Climate change; Cretaceous; DSDP Site 525; Deep Sea Drilling Project; Faunal list; Foraminifera; IPOD; Invertebrata; Isotope ratios; Isotopes; Leg 74; Maestrichtian; Marine environment; Mesozoic; Microfossils; O-18/O-16; Oxygen; Paleoclimatology; Paleoecology; Paleoenvironment; Planktonic taxa; Protista; Quantitative analysis; Senonian; Size; South Atlantic; Stable isotopes; Upper Cretaceous; Upper Maestrichtian
Coordinates: S290415 S290414 E0025908 E0025907
Record ID: 2003062709
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands