Original paper

ERBEN's "Inventory in Stratigraphy" - A model from the California Tertiary Foraminifer Succesion

Berry, William B. N.


The practical use of the California Tertiary stratigraphic succession and its foraminifer faunas in petroleum exploration appears to be a model not only of stratigraphic procedures suggested by ERBEN (1972), but also of application of chrological principles in stratigraphic practice. The California Tertiary succession has been divided to many formations, the distributions of which have been depicted on maps. Fossils, with particular emphasis on the foraminifers in petroleum exploration, have been collected from many of the formations. Analysis of the vertical stratigraphic ranges of the foraminifers has enabled establishment of zones and stages based on unique associations or congregations of species following application of OPPEL's (1856-1858) principle of analyzing the overlapping vertical stratigraphic ranges of species to recognize associations of species that were unique during a limited interval of time. Living benthic foraminifer faunas are distributed down the bathymetric gradient according to temperature and depth. Similar depth zoned faunas may be recognized in the fossil record within the context of the zones and stages. Modern and fossil depth zoned faunas are composed of a number of specific communities, the presence of which is controlled primarily by sediment type. The California Tertiary zones and stages are limited to the California biogeographic province. Radiometric ages have been obtained for a few of the stages based on the evolution of the benthic foraminifers.