Late Paleocene-Early Oligocene palynomorphs from the Côte d'Ivoire-Ghana Transform Margin, eastern Equatorial Altantic: Biostratigraphic and paleoenvironmental significance

Author

Sarah Renée de la Rue

Abstract

"Palynological analysis of thirty-four upper Paleocene to lower Oligocene samples from Holes 959A and 959D of the Cote d’lvoire-Ghana Transform Margin (Leg 159) yielded a rich assemblage of spores and pollen (sporomorphs), marine phytoplankton (dinoflagellate cysts, acritarchs) and microforaminiferal test linings. This passive margin interval was characterized by biosiliceous sedimentation (chert, porcellanite, diatomite) in a deep bathyal, sub-carbonate compensation depth environment. The sporomorph palynoflora consists of 355 taxa, comprising 59 lycophytic and pteridophytic spore species, 10 conifer species, and 286 gymnosperm and angiosperm pollen species. Although the assemblage is dominated by single specimens of dicotyledonous angiosperm pollen, it also contains high counts of inaperturate gymnosperms, indicating a dense, broad-leaved, tropical lowland, continental vegetation cover beyond the coastline, on the West African continent adjacent to the depositional site. In addition, the presence of palm pollen, brackish-water acritarchs, sculptured dicellate fungal spores, wood debris, fresh-water algae, and the paucity of Schizaeaceous fern spores in the samples, suggest a coastal, low- energy environment. The assemblages of coastal and continental plant taxa, in addition to the marine phytoplankton, reflect changing successions of paleovegetation communities, indicating changes in local paleoclimatic and depositional conditions. The presence of key Early Oligocene biomarkers made it possible to assign a precise age for this interval, while other biostratigraphically and ecologically important palynomorph taxa have helped refine the Early-Middle Eocene and the Middle-Late Eocene boundaries in the core sections. With the exception of the Middle Eocene and Early Oligocene, palynostratigraphic zonations were not erected for the entire studied interval, because of the spotty occurrences of marker species"--Abstract, page iv.

Advisor(s)

Oboh-Ikuenobe, Francisca

Committee Member(s)

Gregg, Jay M.
Mattox, Douglas M.

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology and Geophysics

Comments

Acknowledgement is made to the University of Missouri Research Board and to the University of Missouri--Rolla Geology and Geophysics Department for providing partial funding for the project.

Page 103 (Fig. 9) is included in the pdf and also as a supplemental file for greater detail.

Figure 8 is found in the back pocket of the manuscript and contains 4 pages. These are available as separate supplemental files and also are combined into a pdf available in Additional Files.

Publisher

University of Missouri--Rolla

Publication Date

Spring 2000

Pagination

viii, 211 pages

Note about bibliography

Includes bibliographical references (pages 126-137).

Geographic Coverage

Gulf of Guinea

Time Period

Paleocene; Oligocene

Rights

© 2000 Sarah Renée de la Rue, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Thesis Number

T 7776

Print OCLC #

44654571

Recommended Citation

de la Rue, Sarah Renée, "Late Paleocene-Early Oligocene palynomorphs from the Côte d'Ivoire-Ghana Transform Margin, eastern Equatorial Altantic: Biostratigraphic and paleoenvironmental significance" (2000). Masters Theses. 1936.
https://scholarsmine.mst.edu/masters_theses/1936