Article ID Journal Published Year Pages File Type
5780516 Journal of South American Earth Sciences 2017 23 Pages PDF
Abstract
Ostracods are microcrustaceans that inhabit different aquatic environments and are frequently used in paleoecological interpretations and biostratigraphic studies. The Barreirinhas Basin, Northern of Brazil, contains a well-preserved ostracod assemblage in its sedimentary rocks of early and late Cretaceous age, which have been so far poorly studied. This paper contains the first taxonomic identification of the ostracod assemblages, as well as the elaboration of paleoenvironmental and biostratigraphic inferences, for the Cretaceous of the Barreirinhas Basin. The studied material consists of 147 samples from the wells 1-MAS-1A, 1-MAS-3A, 1-MAS-4A and 1-MAS-14A. 495 specimens were recovered, distributed between 40 species, 16 genera and 9 families, including three new species. Based on previously established biozones for the Sergipe basin, two biozones were identified: the Nigeroloxoconcha aff. Nigeroloxoconcha sp. GA A 22 Range Zone, of lower Cenomanian age; and the Brachycythere sapucariensis Interval Zone, of Turonian to middle Coniacian age. Finally, three distinct ostracod assemblages were defined: Assemblage 1, dominated by Conchoecia? species; Assemblage 2, well diversified but with low abundance; and Assemblage 3, with cold water ostracods such as Krithe. Based on the ostracod assemblages identified, a middle neritic, platformal paleoenvironment was inferred for the studied interval.
Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth and Planetary Sciences (General)
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