14. Mesozoic Calcareous Nannofossils from the Indian Ocean, DSDP Legs 22 to 27
- 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
Thierstein, H. R. (1977) Mesozoic Calcareous Nannofossils from the Indian Ocean, DSDP Legs 22 to 27, 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/SP009p0339
- Published Online: 23 MAR 2013
- Published Print: 1 JAN 1977
Print ISBN: 9780875902081
Online ISBN: 9781118664919
All Mesozoic (Oxfordian - latest Maeshrichtian) sediment with a calcium carbonate content exceeding a few percent have been dated by their nannofossil assemblages. Age correlation remains tentative in the early Cretaceous intervals at sites 249, 260, and 263, mainly because of dilution of the nannoplankton by detrital clay. Changes in species compositions and relative abundances reflect the paleolatitudinal positions of the DSDP sites and of some additional sample localities (piston cores and land sections on the surrounding continents). Species diversities, however, are correlated most closely with the degree of dissolution of the assemblages.