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Channel-Belt Scaling Relationship and Application to Lower Miocene Source-to-Sink Systems in the Gulf of Mexico Basin


Reconstruction of paleo-drainage-basins is challenging due, to subsequent tectonism or erosional processes. Yet is well documented in modern systems that basin dimension is correlated with water discharge and sediment flux. Fluvial deposits are volumetrically minor in most basin fills, but the majority of the basin fills transits from source to sink through fluvial channels, and thereby channel flow is a key link between upstream drainage basin and depositional sinks. Sediments deposited in fluvial settings should preserve critical signals that could be used to estimate the key parameters of source-to-sink systems, such as upstream drainage basin area, and thus provide a predictive capability is lacking. In this work, we estimate the drainage areas of fiver lower Miocene river systems in the Gulf of Mexico basin by employing scaling relationships between drainage area and river channel dimensions (e.g., depth) developed in modern and Quaternary Source-to-Sink studies. Channel-belt thickness was used as a proxy to estimate channel depth and was measured from numerous geophysical well logs. Both lower channel-belt thickness and bankfull thickness were measured to estimate the paleo-water depth at low and bankfull stages. Previous paleogeographic reconstruction using detrital zircon U-Pb analysis and continental geomorphic synthesis are used to estimate drainage basin extent independently. Estimated drainage basin area from two independent approaches show limited variation and suggests that bankfull thickness strongly correlates with drainage basin area. The channel bankfull thickness also shows correlation with reconstructed submarine fan dimension. This work demonstrates application to the deep-time stratigraphic archive, where records of drainage basin characteristics are often modified or lost.