Geohistory Analysis—Application of Micropaleontology in Exploration Geology

Abstract “Geohistory analysis” is the use of quantitative stratigraphic techniques to unravel and portray geologic history. Quantification of routine stratigraphic well information is possible as a result of recent advances in microbiostratigraphy that allow exploration paleontologists to determine geologic ages in terms of millions of years, and to express depositional environments in terms of water depth. Geohistory diagrams and numerical stratigraphic techniques, such as the calculation of rates of sediment accumulation and rates of subsidence or uplift (with and without corrections for consolidation), are useful in widely different aspects of petroleum exploration. Knowledge of rates and timing of vertical movements is of local importance in distinguishing between different kinds of movements; these data should constitute a parameter in any structural classification. In a more general sense, such knowledge is a key to understanding basin evolution and plate tectonics.