Kennett, Diana M; Kennett, James P (1990): Bolboforma of Eocene and lower Oligocene sediments of Maud Rise, Weddell Sea [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.753324, Supplement to: Kennett, DM; Kennett, JP (1990): Bolboforma Daniels and Spiegler, from Eocene and lower Oligocene sediments, Maud Rise, Antarctica. In: Barker, PF; Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 667-673, https://doi.org/10.2973/odp.proc.sr.113.208.1990
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Abstract:
Five species of Bolboforma have been found in middle Eocene to lower Oligocene sediments from Maud Rise, Weddel Sea, Antarctica (Leg 113, Holes 689B and 690B), the first reported Bolboforma from the Antarctic Paleogene. The previous oldest known occurrences of Bolboforma in the world's oceans were of late Eocene age and this study extends the known range to the middle middle Eocene (~ 44 Ma). Highest species diversity of Bolboforma in the Weddell Sea region of Antarctica occurred during the late Eocene, after which all but one important species disappeared before the Eocene/Oligocene boundary (36.5 Ma). The remaining species, B. irregularis, disappeared soon after, during the earliest Oligocene. The disappearance of Bolboforma in this region of Antarctica coincided with significant climatic cooling that occurred at the end of the Eocene and during the earliest Oligocene, when subpolar replaced temperate conditions. Bolboforma is not known from younger sediments in the Antarctic except for a brief interval during the late early Miocene, an interval of Neogene climatic warmth. The presence of Bolboforma in Eocene to lower Oligocene sequences in the Weddell Sea region of Antarctica is therefore consistent with this taxon's previously recognized association with temperate water masses. Bolboforma is of limited biostratigraphic value at present, because of relatively long stratigraphic ranges and diachronous extinctions. Previous suggestions that Bolboforma represents an encystment stage of phytoplankton require further critical study because the deposition, in large numbers, at paleodepths up to 2250 m in the open ocean, is an unlikely strategy for an encystment phase of a phytoplanktonic organism.
A new species, Bolboforma antarctica, is described, exhibiting a stratigraphic range from middle middle Eocene to the upper Eocene (~ 44 to 39 Ma).
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Median Latitude: -64.839000 * Median Longitude: 2.152400 * South-bound Latitude: -65.161000 * West-bound Longitude: 1.204900 * North-bound Latitude: -64.517000 * East-bound Longitude: 3.099900
Date/Time Start: 1987-01-16T08:00:00 * Date/Time End: 1987-01-21T07:00:00
Event(s):
113-689B * Latitude: -64.517000 * Longitude: 3.099900 * Date/Time Start: 1987-01-16T08:00:00 * Date/Time End: 1987-01-18T06:45:00 * Elevation: -2091.0 m * Penetration: 297.3 m * Recovery: 229.45 m * Location: South Atlantic Ocean * Campaign: Leg113 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 33 cores; 297.3 m cored; 0 m drilled; 77.2 % recovery
113-690B * Latitude: -65.161000 * Longitude: 1.204900 * Date/Time Start: 1987-01-20T03:15:00 * Date/Time End: 1987-01-21T07:00:00 * Elevation: -2925.0 m * Penetration: 213.4 m * Recovery: 214.75 m * Location: South Atlantic Ocean * Campaign: Leg113 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 25 cores; 213.4 m cored; 0 m drilled; 100.6 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
2 datasets
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Datasets listed in this publication series
- Kennett, DM; Kennett, JP (1990): (Table 1) Range chart for Bolboforma in ODP Hole 113-689B. https://doi.org/10.1594/PANGAEA.753321
- Kennett, DM; Kennett, JP (1990): (Table 2) Range chart for Bolboforma in ODP Hole 113-690B. https://doi.org/10.1594/PANGAEA.753323