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Sinuous channels are common bathymetric features on Earth's continental margins. Until now, the 3D stratigraphy of these features has primarily been inferred from 3D seismic studies and from limited 2D outcrop exposures of ancient successions. The Beacon Channel Complex of the Permian upper Brushy Canyon Formation is an exceptionally wellexposed example of a 3D exposure of a sinuous slope channel system. The Beacon Channel Complex crops out on five cliff facies in an area of approximately 1 km 2 (0.625 mi 2 ). Nearly one complete wavelength of sinuosity is recorded in the outcrop.An integrated data set was used to evaluate the high-resolution, 3D stratigraphy of the Beacon Channel Complex. The stratigraphy of the Beacon Channel Complex is grouped into a hierarchical framework: one channel complex, two channel elements, and five channel stories. Each hierarchical level is empirically related to internal trends of erosional/ depositional energy, thickness, aspect ratio, and amalgamation ratio. Detailed field mapping reveals that the Beacon Channel Complex laterally migrated by both sweep and swing which temporally affected channel sinuosity. Phases of increasing sinuosity are related to channel downcutting, increasing swing, and basinward sweep, whereas phases of decreasing sinuosity are associated with channel filling, decreased swing, and landward sweep. Cross sections at various positions through the sinuous channel reveal patterns associated with facies and architectural asymmetry, reservoir connectivity, cross-sectional area, and preservation potential.The Beacon Channel Complex is an excellent reservoir and outcrop analog to many of Earth's sinuous slope channels on the basis of sinuosity, stratigraphic architecture, and grain size of its fill. This study provides additional knowledge of the 3D stratigraphy and processes of sinuous slope channels and offers a unique perspective that complements studies based on 3D seismic images of subsurface systems and nearseafloor studies of modern systems.

[1] It is now generally accepted that deltas that prograde to the shelf edge are able to transport coarse sediment to deep water either with or without sea level changes. However, it is still unclear how feeder rivers behave differently in the shelf-edge delta case to rivers found in a delta that progrades over the shelf. A series of nine shelf-edge delta experiments are presented to investigate the lateral mobility of the feeder channel at the shelf edge and the associated deep water depositional system under a range of sediment supply rates and shelf-front depths. In the experiments, constant sediment supply from an upstream point source under static sea level led the fluviodeltaic system to prograde over the shallow shelf surface and advance beyond the shelf edge into deep water. The feeder river of the fluviodeltaic system became a bypass system once the toe of the delta front reached the shelf edge. After the delta front was perched at the shelf edge, a submarine fan developed in deep water although remaining disconnected from the delta. In this bypass stage, no regional avulsion or lateral migration of the feeder river occurred and all sediment from the upstream source bypassed the river, delta front, and shelf-front slope. The duration of the bypass stage is proportional to shelf-front depth and inversely proportional to sediment discharge. The combined duration of the shelf-transit phase of the fluviodeltaic system and the bypass phase is the characteristic time scale for the continental margin to "anneal" transgression-inducing perturbation due to high-frequency and/or high-amplitude relative sea level rise. The sequential evolution in the experiment compares favorably to the Eocene Sobrarbe Formation, a shelf-edge delta in Spain, although natural variations are noted. This comparison justifies the application of concepts proposed herein to natural systems and provides insight into interpreting processes from ancient shelf-edge delta systems.

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This study uses measurements from physical experiments to document turbidity currents, which are density currents composed of suspended sediment and water, to be effective at hydrodynamically fractionating minerals on the basis of grain density and grain shape alone, resulting in large‐scale spatial variations in the composition of their deposits. While grain composition varies spatially, the population sampled at any one location is hydrodynamically equivalent. Spatial variations in composition of the deposits are modeled using exponential decay functions, which are based on initial concentration of grain types and their respective differences in settling velocity. We further discuss implications of this process for addressing practical geophysical problems, in which mineralogical distributions are important, such as provenance and geochronology studies, subsurface imaging, and predicting bulk properties of subsurface reservoirs.

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