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Turbidity currents in the ocean are driven by suspended sediment. Yet results from surveys of the modern sea floor and turbidite outcrops indicate that they are capable of transporting as bedload and depositing particles as coarse as cobble sizes. While bedload cannot drive turbidity currents, it can strongly influence the nature of the deposits they emplace. This paper reports on the first set of experiments which focus on bedload transport of granular material by density underflows. These underflows include saline density flows, hybrid saline/turbidity currents and a pure turbidity current. The use of dissolved salt is a surrogate for suspended mud which is so fine that it does not settle out readily. Thus, all the currents can be considered to be model turbidity currents. The data cover four bed conditions: plane bed, dunes, upstream‐migrating antidunes and downstream‐migrating antidunes. The bedload transport relation obtained from the data is very similar to those obtained for open‐channel flows and, in fact, is fitted well by an existing relation determined for open‐channel flows. In the case of dunes and downstream‐migrating antidunes, for which flow separation on the lee sides was observed, form drag falls in a range that is similar to that due to dunes in sand‐bed rivers. This form drag can be removed from the total bed shear stress using an existing relation developed for rivers. Once this form drag is subtracted, the bedload data for these cases collapse to follow the same relation as for plane beds and upstream‐migrating antidunes, for which no flow separation was observed. A relation for flow resistance developed for open‐channel flows agrees well with the data when adapted to density underflows. Comparison of the data with a regime diagram for field‐scale sand‐bed rivers at bankfull flow and field‐scale measurements of turbidity currents at Monterey Submarine Canyon, together with Shields number and densimetric Froude number similarity analyses, provide strong evidence that the experimental relations apply at field scale as well.

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.