An early Maastrichtian organic-walled phytoplankton cyst assemblage from an organic-rich black mud in core Fl-533, Alpha Ridge; evidence for upwelling conditions in the Cretaceous Arctic Ocean

Author(s): Firth, John V.; Clark, David L.
Author Affiliation(s): Primary:
Texas A&M University Research Park, Ocean Drilling Program, College Station, TX, United States
University of Wisconsin-Madison, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 34(1-2), p.1-27. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. 72 refs.; illus., incl. 11 plates, sketch map
Summary: A diverse assemblage of acritarchs, prasinophytes and dinoflagellate cysts occurs in an organic rich black mud in Core Fl-533, taken from the Alpha Ridge, Arctic Ocean. Similarities between this assemblage and others described from the Canadian Arctic allow this black mud to be dated as early Maastrichtian, based primarily on the presence of Cerodinium leptodermum, and the absence of exclusively Campanian and upper Maastrichtian taxa. The high abundance of Comasphaeridium and marine derived amorphous organic matter may indicate a shelf to upper slope environment, possibly deposited during a marine transgression. An abundance of prasinophyte algal cysts, a moderately high peridinioid/gonyaulacoid dinoflagellate cyst ratio, and high species diversity indicate high paleoproductivity, most likely associated with upwelling conditions. When interpreted within the context of two nearby biosiliceous-rich Maastrichtian cores also taken from Alpha Ridge, and from paleogeographic reconstructions, these results indicate that an upwelling region probably existed along the eastern Arctic Ocean during at least part of the Maastrichtian, and formed different sedimentary facies in shelf to slope environments, similar to facies patterns recognized in lower latitude paleo-upwelling regions. Abstract Copyright (1998) Elsevier, B.V.
Year of Publication: 1998
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Acritarchs; Alpha Cordillera; Arctic Ocean; Assemblages; Biostratigraphy; Campanian; Cerodinium leptodermum; Clastic sediments; Comasphaeridium; Cores; Cretaceous; Depositional environment; Dinoflagellata; Maestrichtian; Marine environment; Mesozoic; Microfossils; Morphology; Mud; Organic compounds; Paleo-oceanography; Paleoenvironment; Paleogeography; Palynomorphs; Phytoplankton; Plankton; Prasinophyta; Productivity; Sea-level changes; Sediments; Senonian; Shelf environment; Slope environment; Transgression; Upper Cretaceous; Upwelling
Record ID: 1998042246
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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