Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Johnson, David A (1990): Radiolarian biostratigraphy in the central Indian Ocean [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.728559, Supplement to: Johnson, DA (1990): Radiolarian biostratigraphy in the Central Indian Ocean, Leg 115. In: Duncan, RA; Backmann, J; Peterson, LC; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 115, 395-409, https://doi.org/10.2973/odp.proc.sr.115.156.1990

Always quote citation above when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
Identifiable radiolarians of stratigraphic importance were recovered at eight of the sites drilled on Leg 115. The assemblages range in age from Holocene to middle Eocene (Dictyoprora mongolfieri Zone, about 48 Ma). Faunal preservation is particularly good in two stratigraphic intervals: the Holocene through upper Miocene (0-9 Ma), and the lowermost Oligocene to middle Eocene (35-48 Ma). Fluctuating rates of silica accumulation at these drill sites during the Cenozoic reflect changing tectonic and paleoceanographic conditions. In particular, the gradual closure of the Indonesian and Tethyan seaways and the northward migration of the Indian subcontinent severely restricted zonal circulation and silica accumulation in tropical latitudes during the late Oligocene through middle Miocene. By the late Miocene the Indian subcontinent had moved sufficiently north of the equator to allow trans-Indian zonal circulation patterns to become reestablished, and biosiliceous sedimentation resumed.
The composition of the radiolarian assemblages in the tropical Indian Ocean is closely comparable with that of the 'stratotype' sequences in the equatorial Pacific. However, there are some notable exceptions in Indian Ocean assemblages: (1) the scarcity of the genera Pterocanium and Spongaster in the Neogene; (2) the absence of the stratigraphically important Podocyrtis lineage, P. diamesa -> P. phyxis -> P. ampla, in the middle Eocene; and (3) the scarcity of taxa of the genus Dorcadospyris, with the exception of D. ateuchus.
The succession of radiolarian events was tabulated for those stratigraphic intervals where the assemblages were well preserved. We identified 55 events in the middle Eocene to earliest Oligocene, and 31 events in the late Miocene to Holocene. The succession of events is closely comparable with that of the tropical Pacific. However, there are exceptions that appear to be real, rather than artifacts of sample preservation, mixing, and core disturbance.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Median Latitude: -4.146011 * Median Longitude: 60.612174 * South-bound Latitude: -7.545300 * West-bound Longitude: 59.016800 * North-bound Latitude: -2.742700 * East-bound Longitude: 61.163000
Date/Time Start: 1987-05-07T04:00:00 * Date/Time End: 1987-06-12T15:30:00
Event(s):
115-707A * Latitude: -7.545300 * Longitude: 59.016800 * Date/Time Start: 1987-05-27T14:10:00 * Date/Time End: 1987-05-28T18:30:00 * Elevation: -1553.0 m * Penetration: 213.3 m * Recovery: 160.27 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg115 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 24 cores; 213.3 m cored; 0 m drilled; 75.1 % recovery
115-709A * Latitude: -3.915000 * Longitude: 60.551700 * Date/Time Start: 1987-06-05T01:30:00 * Date/Time End: 1987-06-06T06:30:00 * Elevation: -3047.0 m * Penetration: 203.1 m * Recovery: 184.74 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg115 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 21 core; 203.1 m cored; 0 m drilled; 91 % recovery
115-709C * Latitude: -3.915000 * Longitude: 60.551670 * Date/Time Start: 1987-05-07T04:00:00 * Date/Time End: 1987-06-08T17:00:00 * Elevation: -3039.0 m * Penetration: 353.7 m * Recovery: 330.03 m * Location: South Indian Ridge, South Indian Ocean * Campaign: Leg115 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 37 cores; 353.7 m cored; 0 m drilled; 93.3 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
9 datasets

Download Data

Download ZIP file containing all datasets as tab-delimited text — use the following character encoding:

Datasets listed in this publication series

  1. Johnson, DA (1990): (Table 2) Radiolarian abundance of ODP Hole 115-707A. https://doi.org/10.1594/PANGAEA.728225
  2. Johnson, DA (1990): (Table 3) Radiolarian abundance of ODP Hole 115-709A. https://doi.org/10.1594/PANGAEA.728556
  3. Johnson, DA (1990): (Appendix C) Paleogene radiolarian events in ODP Hole 115-709A. https://doi.org/10.1594/PANGAEA.728231
  4. Johnson, DA (1990): (Table 4) Radiolarian abundance of ODP Hole 115-709C. https://doi.org/10.1594/PANGAEA.728557
  5. Johnson, DA (1990): (Table 5) Radiolarian abundance of ODP Hole 115-710A. https://doi.org/10.1594/PANGAEA.728226
  6. Johnson, DA (1990): (Appendix B) Late Neogene radiolarian events in ODP Hole 115-709A. https://doi.org/10.1594/PANGAEA.728227
  7. Johnson, DA (1990): (Appendix B) Late Neogene radiolarian events in ODP Hole 115-710A. https://doi.org/10.1594/PANGAEA.728229
  8. Johnson, DA (1990): (Table 6) Radiolarian abundance of ODP Hole 115-711A. https://doi.org/10.1594/PANGAEA.728558
  9. Johnson, DA (1990): (Appendix C) Paleogene radiolarian events in ODP Hole 115-711A. https://doi.org/10.1594/PANGAEA.728232