Marine source rock prediction is one element of the lithofacies prediction based on Getech’s Globe Earth System Modelling. Its objective is to produce maps of predicted relative source rock potential, Total Organic Carbon (TOC), and Hydrogen Index as aids to identifying and ranking areas of exploration interest. The approach can also be used for testing source rock scenarios, and for understanding and extrapolating observed data patterns.
Our source rock predictions are based on four foundations: our stage-level global palaeogeographies, the General Circulation Model (GCM) and tidal modelling results based upon them, and the analysis of published modern marine sediment data.
The Palaeogeographies and Digital Elevation Model provide estimates of water depth, distance from land, degree of confinement and palaeolatitude. The GCM modelling provides estimate of freshwater discharge, fluvial sediment flux, coastal upwelling, watermass stratification, oxygen solubility and residence times. Tidal modelling indicates probable shelf mixing regimes and potential grain size patterns. Modern marine data are used to constrain equations determining how variations in primary productivity, carbon flux, sedimentation rate, grain size, dissolved oxygen, and organic matter preservation control the TOC.
The methodology is both quantitative and flexible, and empowers users with the ability to iteratively tune the model to optimise agreement between predictions and observed data. Although the model can be used as a ‘blind test’ to create predictions based purely on theory and modern empirical relationships, observed data (e.g. on sedimentation rate patterns) can also be utilised to improve the results. This is important for higher resolution studies where local rather than generic factors become increasingly important.
Full subscribers can have complete control of the model via a user interface that allows the interactive creation of a large variety of predictive maps employing a wide range of published and custom equations and assumptions. For those that do not require this capability Getech can also provide a range of specified fixed predictions.