KLEINPELL'S BIOSTRATIGRAPHIC ANALYSIS OF CALIFORNIA'S MIOCENE STRATA: HIS ALTERNATIVE TO LAYER CAKE STRATIGRAPHY

When he commenced study of California's Miocene strata in the late 1920s, R. M. Kleinpell understood that the common practice at that time was to describe local geology in terms of layer-cake stratigraphy. He realized that such a procedure was not useful in the quest for petroleum, an enterprise in which he was employed, because of many changes in facies and structural dislocations. He turned to collecting fossil foraminiferans from many stratigraphic sequences and analyzing their vertical ranges through strata to overcome difficulties imposed by the practice of layer-cake stratigraphy. He recognized unique associations of species from the overlapping pattern of species' stratigraphic ranges through considerable thicknesses of strata. The rocks bearing each unique association of species became his zone, and he grouped two or more zones to a stage. These zones and stages became very useful in finding and recovering oil from California's Miocene strata. As studies of strata using fossil foraminiferan associations proceeded, Kleinpell and his associates became aware that chorology, the biogeographic and ecologic patterns in distributions of organisms, constrained these units. These constraints are: 1) biogeographic provinces; 2) relative depth of the sea floor upon which the foraminiferans lived; and 3) habitats in which foraminiferans live. For example, Kleinpell's "pseudo-Saucesian" reflected persistence of bathyal faunas for a significant time interval within the Miocene. Over time, chorology became an integral element in assessment of fossil foraminiferan associations by Kleinpell and his colleagues.