Radiolarian indices of physical and chemical oceanographic phenomena in recent sediments of southern California continental borderland
The California Current, the eastern limb of the North Pacific gyre, exhibits the following characteristics common to eastern boundary currents: wide, shallow, slow, diffuse boundaries; common upwelling; great seasonal variation; invasions of water masses from outside the system; and cold, low-salinity waters. Studies on plankton tows and Holocene sediments have correlated components of the siliceous microplankton (radiolarians and some diatoms) with several characteristics, such as the main directions of movement of the invading waters, the provenance of these waters, the presence and degree of upwelling, and seasonality and its impact on the underlying sediments. Certain types of radiolarians are potentially useful in determining fossil anoxic and oxic conditions as well as paleodepth. In this study, the authors analyzed box-core sediment and plankton tow samples from the southern California continental borderland, as well as radiolarian density, diversity, taxonomic makeup, and other features related to oceanographic and environmental conditions. Depositional environments were defined for the sediment samples, and radiolarian indicators for paleoenvironmental interpretation were determined. Several borderland environments were identified, and the anoxic nearshore basin was found to have the best preservational qualities for radiolarians and thus the most representative radiolarian biocoenosis.
- Research Organization:
- Occidental de Colombia, Inc., Bogota
- OSTI ID:
- 7152256
- Report Number(s):
- CONF-8604187-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:4; Conference: American Association of Petroleum Geologist Pacific Section convention, Bakersfield, CA, USA, 16 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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