Wedge bedding. Successive stack of erosive-based channels creates wedge-shaped bedding cross-sections. Shiguai Formation, Inner Mongolia, China.
Channelized bedding. Erosive scours that backfill with sand may give rise to isolated channelized sandbodies such as this. Mesa Verde Group, Utah.
Tabular cross-bedding. These steep foresets are typical of eolian deposition. Late Jurassic, Liaoning Province, China.
Trough cross-bedding. Trough cross bedding is produced by the downflow migration of lunate dunes in both subaqueous and subaerial environments. Triassic, Hebei Province, China.
Trough cross-bedding. This unusual view is of mud-draped gravel foresets cut by a joint that is oriented parallel to bedding. We are looking down at a cut-away view of an originally horizontal surface. The arcuate surfaces shown were mud drapes on the downstream sides of gravel lunate dunes. Hammer handle points downflow. Note also the wood fragment oriented parallel to flow (just to the left of the hammer handle), and a second set of mud-draped forsets that is cut off by the bottom edge of the photograph.
Wave Ripples. Cross-sectional view of ripple cross-laminated sandstone, showing bi-directional cross laminae indicative of a wave origin. Entrada Formation, Jurassic, San Rafael Swell, Utah.
Ripple Marks. A pile of eroded, rippled beds that all contain gorgeous ripple marks. If you click on nothing else, click to enlarge this one!Carmel Formation, Utah.
Herrigbone cross-stratification. Bi-directional cross beds such as these are indicative of a tidal origin. Curtis Formation, Jurassic, Utah.
Gilbert Delta foresets. These are composite, large-scale foresets that indicate depostion into still water. The height of the foresets indicates the still water depth. Mecca Formation, California.
Climbing current ripples. Ripple foresets that "climb" on the backs of their predecessors are indicative of waning flow conditions and rapid sediment fallout, such that sediment drops out of suspension as fast as it can be molded into a bedform. Entrada Formation, Jurassic, Utah.
Climbing current ripples and convolute lamination. The result of rapid sediment fallout is often instability due to liquefaction, leading to disruption of laminae by water escape. Such disruption is termed convolute lamination. Modern Colorado River, Utah.
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