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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 49 (1965)

Issue: 10. (October)

First Page: 1760

Last Page: 1760

Title: Palynological Survey of Certain Mesozoic-Tertiary Strata in California: ABSTRACT

Author(s): William R. Evitt, John S. Warren

Article Type: Meeting abstract


NSF Grant GP-473 supported a 1-year preliminary palynological study of selected Mesozoic and Tertiary rocks in portions of the Central Valley and Coast Ranges in northern California to determine: (1) where and how palynology can contribute to solving geological problems in the area, and (2) what stratigraphic sequences contain organic microfossils suitable for fundamental paleontological study.

After establishing a laboratory for processing samples, slides from about 800 samples were prepared and examined. These samples were, in part, matrix from specimens in Stanford collections, in part, provided by other agencies and individuals, and, in part, newly collected. Most of the samples are from outcrops. Principal conclusions are:

1. Problems of Franciscan geology are not likely to be solved quickly by use of palynology although contained microfossils permit dating of occasional samples.

2. Two areas of particular promise for future work are: (a) the uppermost Jurassic-Lower Cretaceous sequence north and south of Paskenta west of the Sacramento Valley, and (b) the Upper Cretaceous-lower Tertiary sequence in the belt south of Tracy west of the San Joaquin Valley.

3. Cretaceous-Miocene clastics in the Santa Cruz Mountains generally contain abundant organic matter but only poorly preserved pollen and spores.

4. From lithology or appearance in hand specimens it is not possible to predict with satisfactory consistency how fossiliferous a sample may be or how well preserved its fossils.

5. In many of the better samples dinoflagellates are better preserved and seem to show more striking stratigraphic changes than spores and pollen in the same samples.

As a follow-up of this survey, both taxonomic and stratigraphic studies of dinoflagellates in the areas mentioned in item 2 are now under way. At the same time sampling to delineate additional areas and topics for future research continues.

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Copyright 1997 American Association of Petroleum Geologists