CORRELATION OF UPPER CRETACEOUS (SANTONIAN-MAASTRICHTIAN) DEPOSITIONAL SEQUENCES OF EASTERN ALABAMA
Ostracodes are often very abundant in the samples and more than 1320 specimens were picked for this study. Planktonic foraminifera are less abundant, although some of the key species useful for chronostratigraphic correlation were observed.
Samples collected from the lower Blufftown Formation are assigned to the Veenia quadrialira Taxon Range Zone of mid-Santonian age. Samples collected from the lower Blufftown about 100 feet above the previous samples are equivalent to the Brachycythere pyriforma Interval Zone of early, but not earliest, Campanian age. Samples collected from the upper Blufftown Formation are assigned to the Ascetoleberis plummeri Taxon Range Zone of mid-Campanian age. The chronostratigraphically-significant planktonic foraminiferan Rugotruncana calcarata of mid-Campanian age was found in the upper part of a measured section in the Cusseta Formation and these samples were assigned to the ostracode Escharacytheridea pinochii Interval Zone. A sample collected from the Providence Sand is equivalent to the Floricythereis lixula Interval Zone of Maastrichtian age.
According to the results of this research, the ranges of several species will be extended relative to the composite reference section in central Alabama and will result in improved, high-resolution chronostratigraphic ranges of the species.