کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8913569 1640168 2018 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Late Paleogene-early Neogene dinoflagellate cyst biostratigraphy of the eastern Equatorial Atlantic
ترجمه فارسی عنوان
بیواستراتیگرافی کیست دینوفلاژلد نئوژن زودرس پالئوژن-اولیه نئوژن اقیانوس اطلس اقیانوس اطلس شرقی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی
Six dinoflagellate cyst biozones (zone 1-zone 5, subzones 1a and 1b) are recognized in the late Paleogene-early Neogene interval of the Ocean Drilling Program (ODP) Site 959 (Hole 959 A), Côte d'Ivoire-Ghana Transform Margin in the eastern Equatorial Atlantic. The biozones are based on palynological analysis of 30 samples covering a 273.2-m interval with generally fair preservation and good to poor recovery. We propose a new age of Late Eocene (Priabonian) for subunit IIB as opposed to the previously published mid-Early Oligocene age (middle Rupelian). This age assignment is mainly based on the presence of Late Eocene marker taxa, such as Hemiplacophora semilunifera and Schematophora speciosa in the lower part of the studied interval. We also document for the first time a hiatus event within dinoflagellate cyst zone 3, based on the last occurrences of several taxa. This interval is assigned to an Early Miocene age and is barren of other microfossils. Furthermore, we propose new last occurrences for two species. The last occurrence of Cerebrocysta bartonensis is observed in the late Aquitanian-early Burdigalian in this study vs. Priabonian-early Rupelian in mid and high latitude regions. Also, the last occurrence of Chiropteridium galea extends to the latest Early Miocene (Burdigalian) in ODP Hole 959 A; this event was previously identified in other studies as Chattian in equatorial regions, and Aquitanian in the Northern Hemisphere mid-latitudes. We suspect that these differences are due to physical (offshore vs. nearshore) and latitudinal locations of the areas studied.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of African Earth Sciences - Volume 140, April 2018, Pages 267-281
نویسندگان
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