--> A Source-to-Sink Approach to Drainage and Sediment Flux in Thrust and Foreland Systems: Example From the Cretaceous Sevier and Laramide Provinces, Western Interior Basin, USA

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A Source-to-Sink Approach to Drainage and Sediment Flux in Thrust and Foreland Systems: Example From the Cretaceous Sevier and Laramide Provinces, Western Interior Basin, USA

Abstract

Fold and thrust belts and adjacent foreland basins at first appear as relatively simple source-to-sink systems in terms of drainage and temporary storage and ultimate permanent sediment deposition in the foreland basin. Sediment routing from the hinterland should in principle be directed in a relatively predictive manner to the foreland basin albeit through one or more piggyback basins. Key learnings from application of source-to-sink methodology to various other tectonic settings suggest there are semi-quantitative relationships between for example areal size of the catchment and the area and volume of marine deposits. This relationship implies only limited permanent storage of sediment en route to the ultimate sink, and insignificant loss of sediment out of the source-to-sink system. Several challenges exist to establish a reliable source-to-sink methodology in thrust and foreland systems: (i) Catchments and antecedent drainage systems are not commonly preserved or easily observable in thrust and fold belts because of cannibalization of these areas during continued thrusting. (ii) Where significant piggyback basins are formed, lateral drainage out of the system is likely as well as permanent sediment storage in the piggyback basins. (iii) In thrust and foreland systems with significant foreland deformation, sediments can be sourced from foreland uplift areas thus adding sediment volumes from other sources than the thrust belt itself. (iv) Extensional collapse of the thrust belt itself may form drainage in alternate directions to from the thrust belt to the foreland. The Utah-Idaho-Wyoming thrust belt in the western USA formed largely from the early Cretaceous to the early Paleogene. It shows prominent examples of the complexities of the thrust belt to foreland basin source-to-sink systems, and offers unresolved challenges in terms of correlating between thrust belt and foreland. A source-to-sink approach offers at least a qualitative framework for understanding drainage, transport/bypass and intermediate and permanent sediment storage despite that various parts of the source-to-sink system are not preserved, such as the catchment. Modern and Recent systems in the area yield substantial information about the antecedent development of the Utah-Wyoming thrust system and can offer proxy data for establishment of at least a semi-quantitative relationships between various source-to-sink segments in the Utah-Idaho-Wyoming thrust and foreland system.