16. Distribution of Calcareous Nannoplankton in Oligocene to Holocene Sediments of the Red Sea and the Indian Ocean Reflecting Paleoenvironment
- J.R. Heirtzler,
- H.M. Bolli,
- T.A. Davies,
- J.B. Saunders and
- J.G. Sclater
Published Online: 23 MAR 2013
Copyright © 1977 by the American Geophysical Union.
Indian Ocean Geology and Biostratigraphy
How to Cite
Müller, C. (1977) Distribution of Calcareous Nannoplankton in Oligocene to Holocene Sediments of the Red Sea and the Indian Ocean Reflecting Paleoenvironment, in Indian Ocean Geology and Biostratigraphy (eds J.R. Heirtzler, H.M. Bolli, T.A. Davies, J.B. Saunders and J.G. Sclater), American Geophysical Union, Washington, D. C.. doi: 10.1029/SP009p0371
- Published Online: 23 MAR 2013
- Published Print: 1 JAN 1977
Print ISBN: 9780875902081
Online ISBN: 9781118664919
Results of the nannoplankton investigations of Oligocene to Holocene sediments from 52 sites, drilled in the Indian Ocean (Fig. 1, Fig.2) during the Deep Sea Drilling Project (Leg 22 to Leg 29) are presented.
Nannofossils are the main constituent of the pelagic sediments, especially the Cenozoic chalks and oozes, covering the ridges and deep basins of the Indian Ocean. Their distribution and preservation in the sediments recovered from the different sites is closely related to depositional conditions reflecting the paleoenvironment which in turn is strongly connected with the tectonic evolution of the Indian Ocean.
Nannoplankton assemblages of low- and mid-latitude regions of the Indian Ocean are similar. A decrease in frequency of some groups (discoasters, ceratoliths, sphenoliths) can be observed in mid-latitudes. However, most index fossils occur also there. This makes it possible to use the same zonation in nearly all parts of the Indian Ocean. Assemblages of high-latitudes or areas influenced by the Circumpolar Current (Crozet Basin) are distinguished by low species diversity, thus a modified zonation must be used.