Unusual silicoflagellate skeletal morphologies from the upper Miocene-lower Pliocene; possible ecophenotypic variations from the high-latitude southern oceans

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doi: 10.1002/9781118668061.ch10
Author(s): McCartney, Kevin
Author Affiliation(s): Primary:
University of Maine at Presque Isle, Micropaleontology Undergraduate Research Laboratory, Presque Isle, ME, United States
Other:
Florida State University, United States
Volume Title: Antarctic paleoenvironment; a perspective on global change; Part two
Volume Author(s): Kennett, James P., editor; Warnke, Detlef A.
Source: The Antarctic paleoenvironment; a perspective on global change; Part two, edited by James P. Kennett and Detlef A. Warnke. Antarctic Research Series, Vol.60, p.195-206. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0066-4634. ISBN: 978-1-118-66806-1 CODEN: ANTSA4
Note: In English. 16 refs.
Summary: Six unusual morphotypes of the silicoflagellate subspecies Distephanus speculum speculum constitute the "pseudofibula plexus," the distribution of which is concentrated in uppermost Miocene-lowermost Pliocene sediments centered around the antarctic continent. The occurrence of this plexus in antarctic and subantarctic waters seems to correlate with the Late Miocene-Early Pliocene glaciations of the continent. Therefore some type of ecologic control is suspected to account for its distribution in time and space. Distribution maps show that members of the plexus dominate silicoflagellate assemblages closest to the continent (class I province) but that their numbers diminish away from the continent (through class II and class III provinces), as does the thickness of the interval they occupy; thus the stratigraphic boundaries of the plexus may be diachronous. Only at Ocean Drilling Program Site 704 on Meteor Rise does the plexus occur in a continuous pelagic carbonate sequence with well-developed stable isotope and magnetobiostratigraphy. Its first abundance peak at that site, just above the base of the Messinian Stage, corresponds with a major interglacial event recorded in the planktonic and benthic foraminiferal isotopic records, an episode believed to have produced significant melting of the continental ice sheet and the injection of low-salinity meltwaters across the surface of the southern ocean. (Auth. mod.)
Year of Publication: 1993
Research Program: ODP Ocean Drilling Program
Key Words: 10 Paleontology, Invertebrate; Antarctic Ocean; Biostratigraphy; Cenozoic; Glaciation; Invertebrata; Leg 114; Lower Pliocene; Messinian; Meteor Rise; Microfossils; Miocene; Morphology; Morphotypes; Neogene; ODP Site 704; Ocean Drilling Program; Paleoclimatology; Pliocene; Protista; Pseudofibula plexus; Silicoflagellata; Tertiary; Tests; Upper Miocene; Upwelling
Coordinates: S465246 S465245 E0072515 E0072515
Record ID: 1994044018
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from the Antarctic Bibliography, United States