Model for Predicting Paleoproductivity and Source Rock Distribution

Eric J. Barron, Eddy Kruijs

The capability of a three-dimensional climate model to predict upwelling and productivity and to evaluate other environmental factors that would influence preservation of organic material is systematically evaluated by the following steps. (1) Correlations between present-day wind-driven upwelling and productivity are determined using global data sets for each variable. Poor correlations exist in the open ocean and in areas of seasonal sea-ice cover. Excellent correlations are found in coastal regions. (2) The capability of the model to predict present-day upwelling is determined. Approximately 80% of the model predictions are confirmed by observations. (3) The differences between predictions for the present-day seasonal cycle and the Cretaceous seasonal cycle are evaluat d. Especially in considering seasonal upwelling, the Cretaceous predictions are markedly different from the present-day predictions. (4) The Cretaceous predictions were tested using upwelling and high productivity indicators. The Cretaceous predictions are accurate in 90% of the cases where data are available for comparison. (5) Freshwater runoff and storm tracks predicted by the model are used to eliminate areas of predicted upwelling that may not be conducive to preservation.

Evaluation and testing of the model have proven highly successful and suggest this model is ready to become an additional applied tool in source rock prediction.

AAPG Search and Discovery Article #91022©1989 AAPG Annual Convention, April 23-26, 1989, San Antonio, Texas.