Miocene to Pliocene calcareous nannofossil biostratigraphy at ODP Leg 177 Sites 1088 and 1090

Author(s): Marino, Maria; Flores, José Abel
Author Affiliation(s): Primary:
Universita di Bari, Dipartimento di Geologia e Geofisica, Bari, Italy
University of Florida, United States
Universidad de Salamanca, Spain
Volume Title: Southern Ocean Eocene-Pleistocene stratigraphies; insights from ocean drilling
Volume Author(s): Gersonde, Rainer, editor; Hodell, David A.
Source: Southern Ocean Eocene-Pleistocene stratigraphies; insights from ocean drilling, edited by Rainer Gersonde and David A. Hodell. Marine Micropaleontology, 45(3-4), p.291-307. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. Includes appendix. 46 refs.; illus., incl. strat. col., 2 tables, sketch map
Summary: The calcareous nannofossil biostratigraphy of ODP Leg 177 Sites 1088 and 1090 (Subantarctic sector from the Atlantic Ocean) is discussed. Most nannofossil zonal boundaries of and were recognized for the studied mid-high-latitude sediments. Conventional low-latitude marker species such as Amaurolithus spp., Discoaster spp., Triquetrorhabdulus spp., Ceratolithus spp. were recorded as rare and scattered, which impeded the development of a detailed nannofossil biostratigraphic zonation of some Miocene and Pliocene intervals. Because of the absence of some primary biostratigraphic marker species, additional second-order bioevents, such as the first occurrence of Calcidiscus macintyrei and the last occurrence of Coccolithus miopelagicus, have been used to approximate the base of zones NN7 and NN8, respectively. Several disconformities disturbing the Pliocene and Miocene intervals of Site 1090 could be determined based on nannofossil distribution although the occurrence of intervals with dissolved nannofloras and low species diversity prevented a reliable age assignment. An acme of small Gephyrocapsa was recognized near the lower/middle Pliocene boundary, close to the NN15-NN16 zonal boundary, presenting an event for further improvement of the calcareous nannofossil biostratigraphy of this interval time. The first occurrence of Pseudoemiliania lacunosa (>4 µm) occurs close to this interval, representing a fairly reliable event to approximate the base of NN15 zone when other biozonal events are absent. A paracme of R. pseudoumbilicus (>7 µm) was detected in the lower Pliocene NN12 and in the upper Miocene NN11. These temporary absences of the species seem to be isochronous between high-latitude and low-middle-latitude areas. Abstract Copyright (2002) Elsevier, B.V.
Year of Publication: 2002
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Atlantic Ocean; Biostratigraphy; Biozones; Calcidiscus macintyrei; Cenozoic; Coccolithophoraceae; Coccolithus; Coccolithus miopelagicus; First occurrence; Floral list; Leg 177; Marine environment; Marine sediments; Microfossils; Miocene; Nannofossils; Neogene; ODP Site 1088; ODP Site 1090; Ocean Drilling Program; Plantae; Pliocene; Pseudoemiliania lacunosa; Sedimentation; Sedimentation rates; Sediments; South Atlantic; Southern Ocean; Taxonomy; Tertiary
Coordinates: S410810 S410810 E0133346 E0133346
S425449 S425449 E0085359 E0085359
Record ID: 2002063093
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands