Radiolarian stratigraphy across the Oligocene/Miocene transition

Author(s): Sanfilippo, Annika; Nigrini, Catherine
Author Affiliation(s): Primary:
Scripps Institution of Oceanography, La Jolla, CA, United States
Volume Title: Marine Micropaleontology
Source: Marine Micropaleontology, 24(3-4), p.239-285. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. 71 refs.; illus., incl. 4 plates, 18 tables, sketch map
Summary: Recently the International Union of Geological Sciences (Commission on Stratigraphy, Working Group on the Paleogene/Neogene Boundary) proposed that the Oligocene/Miocene boundary be placed at the base of Chron C6Cn2n at 23.8 Ma on the Cande and Kent (1992) magnetic time scale, where it is approximated by planktic foraminifera at the first occurrence of Globorotalia kugleri, and by calcareous nannofossils at the last occurrence of Sphenolithus ciperoensis and the first and last occurrences of Sphenolithus delphix and S.capricornutus. Herein we show that, in terms of radiolarians, the base of Chron C6Cn2n can be correlated with the upper part of the Lychnocanoma elongata Zone between the last occurrence of Artophormis gracilis (23.94 Ma) and the first occurrence of Cyrtocapsella tetrapera (23.69 Ma). Since the proposed stratotype at Lemme-Carrosio (Italy) does not contain radiolarians at the boundary, we re-examined 13 DSDP sites and established the stratigraphic sequence of 29 first and last radiolarian occurrences and one evolutionary transition across the boundary. Nine of these sites contain both calcareous and siliceous microfossils and thus allow for an integrated biostratigraphy. Paleomagnetic stratigraphy is not available for any of the DSDP cores examined. However, use of Hodell and Woodruff's (1994) strontium isotope curve from DSDP Site 289 has permitted calibration of several low latitude microfossil datum levels against the geomagnetic polarity scale. Two new species, Lychnocanoma apodora and Eucyrtidium plesiodiaphanes, are described.
Year of Publication: 1995
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Assemblages; Atlantic Ocean; Biologic evolution; Biostratigraphy; Biozones; Caribbean Sea; Cenozoic; DSDP Site 146; DSDP Site 151; DSDP Site 160; DSDP Site 167; DSDP Site 216; DSDP Site 217; DSDP Site 289; DSDP Site 315; DSDP Site 317; DSDP Site 366; DSDP Site 448; DSDP Site 543; DSDP Site 573; DSDP Site 574; DSDP Site 64; DSDP Site 69; DSDP Site 70; DSDP Site 71; DSDP Site 77; Deep Sea Drilling Project; Eucyrtidium plesidiaphanes; IPOD; Index fossils; Indian Ocean; Invertebrata; Leg 15; Leg 16; Leg 17; Leg 22; Leg 30; Leg 33; Leg 41; Leg 59; Leg 7; Leg 78A; Leg 8; Leg 85; Leg 9; Lychnocanoma apodora; Microfossils; Miocene; Morphology; Neogene; New taxa; North Atlantic; Oligocene; Pacific Ocean; Paleogene; Phylogeny; Preservation; Protista; Radiolaria; Reworking; Stratigraphic boundary; Stratotypes; Taxonomy; Tertiary
Record ID: 1995027093
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands

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