Sedimentary origin of North Atlantic Cretaceous palynofacies

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doi: 10.1029/ME003p0420
Author(s): Habib, D.
Volume Title: Deep drilling results in the Atlantic Ocean; continental margins and paleoenvironment
Volume Author(s): Talwani, M., editor; Hay, W.; Ryan, W. B. F.
Source: Maurice Ewing Series, 3, p.420-437; Deep drilling results in the Atlantic Ocean; continental margins and paleoenvironment, Harriman, N.Y., March 19-25, 1978, edited by M. Talwani, W. Hay and W. B. F. Ryan. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0197-6346. ISBN: 978-1-118-66583-1 CODEN: MEWSDN
Note: In English. 24 refs.; illus. incl. plates, geol. sketch maps
Summary: Carbonaceous particles of terrestrial and marine origin are used to define four sedimentary palynofacies in Cretaceous sections cored in the North Atlantic. The exinitic facies contains sporomorph assemblages and structured palynodebris compositionally close to those in coeval fluviodeltaic sediments on continents bordering the North Atlantic, and it is concluded that they were deposited by turbidity currents near a deltaic source. The tracheal facies is of similar origin, except that marine currents sorted sporomorph species and admixed dinoflagellates prior to deposition. Both the xenomorphic and micrinitic facies contain dinoflagellates, bisaccate pollen, Classopollis and abundant amorphous palynodebris. Xenomorphic palynodebris is unknown palynologically, but is associated with pelagic lithology. Micrinitic palynodebris is considered to be the carbonized (fusinized?) woody tissue of land plants which were carried into offshore areas of the Cretaceous North Atlantic. The micrinitic facies in black shales reflects the much diminished supply of terrigenous organic detritus, most of which is micrinitic palynodebris. The stratigraphic distribution of palynofacies is compared with published organic carbon data. Higher carbon percentages are associated with the exinitic and tracheal facies, which indicates that the increased carbon content was derived from land plants during episodes of increased deltaic activity. The occurrence of dinoflagellates in the latter palynofacies requires the admixture of marine carbon, however. The darker color of the black shales may be due to the nature of the micrinitic palynodebris rather than total carbon content alone. Evidence is presented for episodes of increased deltaic activity during the Valanginian, Barremian-early Aptian, and late Aptian/early Albian. Abstract Copyright 1979 by the American Geophysical Union.
Year of Publication: 1979
Research Program: DSDP Deep Sea Drilling Project
Key Words: 06 Petrology, Sedimentary; Algae; Alisporites; Assemblages; Atlantic Ocean; Biostratigraphy; Carbonaceous composition; Classopollis; Cretaceous; Deep Sea Drilling Project; Environment; Marine environment; Mesozoic; Microfossils; Miospores; Nannofossils; North Atlantic; North Atlantic Ocean; Oceanography; Palynomorphs; Pinuspollenites; Plantae; Pollen; Research; Sedimentary petrology; Sedimentation; Stratigraphy; Thallophytes
Record ID: 1980017771
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.

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