A larger benthic foraminiferal zonation for the Eocene of the Caribbean and central American region


Mitchell S. F. , Robinson E., Özcan E. , Jiang M. M. , Robinson N.

CARNETS DE GEOLOGIE, vol.22, no.11, pp.409-566, 2022 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 11
  • Publication Date: 2022
  • Doi Number: 10.2110/carnets.2022.2211
  • Title of Journal : CARNETS DE GEOLOGIE
  • Page Numbers: pp.409-566
  • Keywords: Key- Lepidocyclinidae, Nummulitidae, Helicosteginidae, Eocene, biostratigraphy, American Larger Benthic Foraminifer (LBF) zones, GULF-OF-MEXICO, WHITE LIMESTONE, PROLOCULUS SIZE, ST-BARTHOLOMEW, WESTERN, BIOSTRATIGRAPHY, PALEOGENE, LEPIDOCYCLINA, STRATIGRAPHY, PALEOCENE

Abstract

We have undertaken a study of the larger benthic foraminifera (LBF) of the Eocene of Ja-maica that involved collecting free specimens and calibrating their occurrence against chronostratigra-phy using calcareous nannofossils identified from sample splits or adjacent samples. The results have been plotted stratigraphically and allow a detailed zonation of the Eocene (14 zones) to be developed based largely on lepidocyclinids and similar forms. The zonation can be shown to be applicable to the Americas extending from northern South America, to Central America, the Caribbean and southern North America. The LBF biostratigraphy is based on the evolution of various groups. Three zones are recognized in the Ypresian, six zones in the Lutetian, three zones in the Bartonian, and two zones in the Priabonian. In order to classify the LBF we have revised the important groups used for the zonation scheme that occur in the Eocene and figure numerous examples. Our revision rearranges described genera into evolutionary, monophyletic clades to which we give the hierarchy of family and subfamily. We provide remarks on published taxa explaining how they are recognized and describe all the new taxa (two families, one subfamily, four genera and five species). The following families, genera and species are new: Butterliniana gen. nov., Helicosteginidae fam. nov., Helicostegina minor sp. nov., Helicostegina jamaicensis sp. nov., Helicostegina jeannemairae sp. nov., Pseudolepidinidae fam. nov., Orbitoininae subfam. nov., Planorbitoinella gen. nov., Polyorbitoinella gen. nov., Polyorbitoinella lily-fieldensis sp. nov., Orbitoina wrighti sp. nov., and Nephronummulites gen. nov.