Back to species list
Holocene Radiolaria from Sediments of the Gulf of California
Text by: Richard N. Benson (2005)
The following text (in the pdf-file) is excerpted and revised from my 1966 Ph.D. thesis from the University of Minnesota, Minneapolis, Minnesota, USA, "Recent Radiolaria from the Gulf of California." It reflects the information about the Gulf of California (with a few more recent updates) and the state of radiolarian taxonomy available at that time. I am indebted to William R. Riedel of the Scripps Institution of Oceanography who introduced me to and first mentored me on the study of these beautiful siliceous protist skeletons.
In 2003, I spent two months in Oslo, Norway, with Kjell Bjørklund and Jane Dolven to revise and update the taxonomy of the radiolarian taxa I defined and described in 1966 and which now appear in www.radiolaria.org under Radiolarian species info: Holocene (Recent)---Gulf of California. The Appendix lists the revised names followed by Benson's (1966) names and cited illustrations that conform to our 2003 concept of each taxon.
I have included summaries of later studies of radiolarian distributions in the Gulf by Molina-Cruz (1986), Pisias (1986), and Molina-Cruz et al. (1999). I have renamed taxa listed in those studies to reflect the updated taxonomy found in Radiolaria.org. See the synonymies in Radiolaria.org for each taxon for names used by the above authors in their studies.
Benson (2005) (pdf, 1.1 MB)
Contents of pdf-file
Gulf of California Radiolarian Sampling Sites and Procedures | p. 3 |
Gulf of California Submarine Topography | p. 6 |
Gulf of California Sediments | p. 9 |
Biogenous Components | p. 9 |
Gulf of California Climate and Oceanography | p. 13 |
Climate | p. 13 |
Horizontal Distribution of Properties | p. 13 |
Vertical Distribution of Properties | p. 14 |
General Circulation | p. 15 |
Upwelling and Biological Productivity | p. 16 |
Distribution of Radiolarians in Surface Sediments of the Gulf of California (Benson, 1966) | p. 20 |
Total Number of Taxa | p. 21 |
Spumellarian/Nassellarian (S/N) Test Ratio | p. 21 |
Spumellarian/Nassellarian (S/N) Taxon Ratio | p. 21 |
Radiolarian Assemblages | p. 21 |
Predominant Taxa in Holocene Sediments of the Gulf of California. | p. 22 |
Upwelling/diatomite assemblage | p. 23 |
Relative Abundances of Dominant Taxa | p. 25 |
Later Studies of Radiolarian Distributions in the Gulf of California | p. 26 |
Molina-Cruz (1986) | p. 26 |
Molina-Cruz et al. (1999) | p. 27 |
Pisias (1986) | p. 28 |
Radiolarian Systematics | p. 30 |
Age of the Gulf assemblage | p. 30 |
Ontogeny of the test | p. 30 |
Availability of silica | p. 31 |
Morphology of spumellarian tests | p. 31 |
Morphology of nassellarian tests | p. 31 |
References Cited | p. 39 |
Appendix | p. 41 |
Suprageneric Classification and List of Gulf of California Holocene Radiolaria | p. 41 |
|