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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 49 (1965)

Issue: 3. (March)

First Page: 337

Last Page: 337

Title: Palynology of Modern Sediments, Gulf of California and Environs: ABSTRACT

Author(s): Aureal T. Cross, Bernard L. Shaefer

Article Type: Meeting abstract


Several hundred bottom samples from the Gulf of California, distributed systematically over its entire area, and comparable samples from streams and arroyos in all surrounding areas, have been analyzed for spore and pollen content and for qualitative and quantitative relationships of various groups of these palynomorphs to each other and to other associated organic entities of comparable size.

Some of the more conspicuous concentration patterns of these palynormorphs indicate distance from shoreline, current patterns, depth of water, coarseness of sediment, seasonal wind patterns, and some source-vegetation distribution areas. Other distribution patterns are complicated by unidentified factors or combinations of factors among which the principal controlling agency is not discernible.

Conspicuous concentrations of spores occur off the months of the major tributary streams, adding evidence to the conclusion that stream transportation plays an important role in spore distribution. Spores from the mainland, particularly from the slopes of the Sierra Madre Occidental, reach the Gulf principally by way of the streams because the prevailing winds would not contribute extensively from this direction. A heavy concentration of palynomorphs off LaPaz is due in part to the effects of wind distribution from the tropical vegetation on the southern tip of the Baja Peninsula and in part to the interruption of the long-shore currents by the configuration of the structurally controlled southern tip of the peninsula and by the position of some offshore islands.

There is generally an increase in total number of palynomorphs seaward from very low amounts in the narrower belt of shallower coastal waters, and then a gradual diminution toward the center of the Gulf. The pollen frequency is less in the very shallow areas and in the very deep basins. Relative frequencies of spores are about the same for the various types of sediments except the coarser types. Some correlation of patterns of palynomorphs and radiolarians is indicated, but there is no clear relation of spore patterns to the distribution of diatoms and some other organisms.

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Copyright 1997 American Association of Petroleum Geologists