Age of the California Lower Tertiary Stages with Respect to Extra-Californian and European Types
Published:January 01, 1959
1959. "Age of the California Lower Tertiary Stages with Respect to Extra-Californian and European Types", Lower Tertiary Biostratigraphy of the California Coast Ranges, V. Standish Mallory
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It is not until the close of Lower Tertiary time with the onset of Narizian faunas that we find significant resemblance with the recent faunas of the West Coast. The costate Bulimina and the inflated hispid Uvigerina are markedly similar and very probably related to living deep water and colder-water species. Possibly the deepening of waters and consequent cooling has brought about this similarity. Abundant lagenid faunas of the Eocene are found today primarily in warmer waters of the Caribbean and Indo-Pacific. Because so few species are conspecific with Recent foraminifers, it is doubtful if any percentages of living versus fossil forms have any significance unless Lyellian methods are strictly adhered to (Kleinpell, pp. 171–2). Using distinctive forms in the Kreyenhagen shale and Point of Rocks formation of the Devils Den as Linnean species, and these two lithologic entities as a unit, diagnosis of living and fossil forms resulted in an average of 0.5–1 per cent Recent forms in Narizian faunas.
We have not yet progressed to the point where we can confidently correlate between Europe and North America with any degree of certainty. Some hope for this correlation is offered, however, by the widespread uniformity of Lower Tertiary climates throughout the world. The lack of pronounced provincialism, which is particularly true of the Paleocene-Middle Eocene, makes possible an approximation of correlation with an error perhaps no greater than zone-magnitude at best, and possibly stage or sub-stage magnitude, in other cases.
The best European correlation seems to be offered by
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Lower Tertiary Biostratigraphy of the California Coast Ranges
As a result of field work carried on in 1947 a sequence of foraminiferal samples were collected in 2,300 feet of Lower Tertiary mudstones, siltstones, and interbedded shales and sandstones in the vicinity of Media Agua Creek, in the Temblor Range on the west side of the San Joaquin Valley.
Foraminiferal samples from another less comprehensive sequence of Lower Tertiary strata were collected during the years 1947, 1948, and 1949 in the region of Devils Den.
The prepared samples were studied during the years 1947–1952 in the Department of Paleontology at the University of California under the direction of Dr. Robert M. Kleinpell. Subsequent work both in the field and laboratory has been directed toward obtaining as complete and chronologically diagnostic a faunal sequence throughout the Lower Tertiary in the California province as possible.
Preliminary results of certain phases of the investigation have been presented from time to time at meetings of the Pacific Section of the American Association of Petroleum Geologists, San Joaquin Valley Geological Society, Cordilleran Section of the Geological Society of America, and the Northwest Geological Society (Mallory and Boyd, 1949; Mallory, 1953a, 1953b, 1954a, 1954b). This paper attempts a synthesis and revision of these reports and their conclusions, and the incorporation of many new data.
The majority of species known to be important in the Paleogene foraminiferal faunas are figured and their stratigraphic distribution in the California province is noted. In addition, an attempt has been made to draw any inferences from all kinds of fossil