Late Miocene-early Pliocene planktonic Foraminifera and palaeoceanography of the North Atlantic

Online Access: Get full text
doi: 10.1144/jm.9.2.145
Author(s): Hooper, Peter W. P.; Funnell, Brian M.; Weaver, Philip P. E.
Author Affiliation(s): Primary:
18 Edward Avenue, Bishopstoke, Eastleigh, United Kingdom
University of East Anglia, United Kingdom
Institute of Oceanographic Sciences, United Kingdom
Volume Title: Cenozoic biostratigraphy and global change
Volume Author(s): Funnell, Brian M., editor
Source: Journal of Micropalaeontology, 9(2), p.145-151; British Micropalaeontological Society meeting on Cenozoic biostratigraphy and global change, Norwich, United Kingdom, May 1989, edited by Brian M. Funnell. Publisher: British Micropalaeontological Society, London, United Kingdom. ISSN: 0262-821X
Note: In English. 8 refs.; illus., incl. 1 plate, 1 table, sketch maps
Summary: Relative abundance variations of planktonic Foraminifera have been studied for the Late Miocene to Early Pliocene time interval of 7.0 to 3.5 Ma from three sites in the North East Atlantic; DSDP607 (41°N), DSDP609 (50°N) and DSDP611 (53°N), Particular attention has been given to the percentage of benthic Foraminifera of total (benthic + planktonic) Foraminifera as an index of dissolution by aggressive bottom waters, and to the percentage of dextral Neogloboquadrina pachyderma of total (dextral + sinistral) N. pachyderma as an index of "Sub-Polar" or warmer waters. Strong dissolution, probably associated with the northward penetration of aggressive Antarctic Bottom Water, is observed at two of the sites up to and during the initiation of the Messinian "Salinity Crisis" in the adjoining Mediterranean Sea at about 5.8 Ma. All three sites exhibit strong cyclic fluctuations of the percentage of dextral N. pachyderma during the Messinian "Salinity Crisis" interval, from approximately 5.8 Ma to 4.8 Ma. These are interpreted as indicating wide-ranging oscillations of a water mass boundary, analogous to the present-day Polar Front, in the North Atlantic during the "Salinity Crisis". Following the re-filling of the Mediterranean with normal marine waters at about 4.8 Ma, the dextral form of N. pachyderma, which is more characteristic of warmer waters than the sinistral form, becomes the dominant form and shows less quantitative variation at all three sites throughout the Early Pliocene.
Year of Publication: 1991
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Assemblages; Atlantic Ocean; Carbonate compensation depth; Cenozoic; DSDP Site 607; DSDP Site 609; DSDP Site 611; Deep Sea Drilling Project; Foraminifera; Globigerinacea; IPOD; Invertebrata; Leg 94; Lower Pliocene; Marine environment; Microfossils; Mid-Atlantic Ridge; Miocene; Morphology; Neogene; Neogloboquadrina; Neogloboquadrina pachyderma; North Atlantic; Northeast Atlantic; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Paleosalinity; Paleotemperature; Planktonic taxa; Pliocene; Protista; Rotaliina; Sea-surface temperature; Tertiary; Tests; Upper Miocene
Coordinates: N410004 N410005 W0325726 W0325727
N495240 N495241 W0241417 W0241418
N525009 N525029 W0301834 W0301906
Record ID: 2015014534
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom