Abstract: Middle Eocene Through Basal Miocene Sequence Biostratigraphy of the Western Gulf Coastal Region

Mark M. Jiang

This study documents stratigraphic occurrences of nannofloral pulses in the middle and upper Eocene, Oligocene, and basal Miocene of the western Gulf coastal plain of Texas and Louisiana. The identified pulses correspond to regional foraminiferal tops, and when plotted against geologic time their relative magnitudes show a sinuous pattern imaging the third-order cycles of Haq et al. (1988). Results of comparison suggest that the Reklaw is correlated with TA3.1, Queen City with TA3.2, and Weches with TA3.3. The Cook Mountain consists of three genetic units correlated with TA3.4, TA3.5, and TA3.6. The lower Yegua consists of two packages correlated with TA4.1 and TA4.2. The upper Yegua is correlated with TA4.3, Jackson with TA4.4, and Vicksburg with TA4.5. The "Transvicks" characterized by Textularia tumidulum was developed during the lowest sea level cycle, TB1.1, in the Oligocene. Two clusters of floral pulses in the Frio are correlated with TB1.2 and TB1.3. Two younger clusters of floral pulses in the Anahuac are correlated with TB1.4 and TB1.5. Absolute ages of these third-order sequences are reevaluated, based on occurrences of nannomarkers in corresponding floral pulses.

AAPG Search and Discovery Article #90983©1994 GCAGS and Gulf Coast SEPM 44th Annual Meeting, Austin, Texas, October 6-7, 1994