CROSS-BEDDING is a feature that occurs at various scales, and is observed in conglomerates and sandstones. RIPPLE MARKS are produced by flowing water or wave action, analogous to cross-bedding (see above), only on a smaller scale (individual layers are at most a few cm thick). In geology, ripple marks are sedimentary structures (i. Small cross-bedding are ripples set at a height less than ten centimeters, while the thickness is only a few millimeters. Cross bedding is very common in beach deposits, sand dunes, and river deposited sediment. Ripple marks are characteristic of shallow water deposition.
Trough cross bedding is produced by the downflow migration of lunate dunes in both subaqueous and subaerial environments. A pile of eroded, rippled beds that all contain gorgeous ripple marks. First up: some ripple-marks and cross-beds, which are really the same thing viewed in three dimensions vs. being viewed in cross-section. Ripple marks are present as undulations on a non- cohesive surface, though they may also be found infrequently in muddy sediments as well. Note the trough cross-bedding on the cut that is perpendicular to flow (i.e. the v-w cut) This figure shows flow along the bed across a set of sinuous-crested bedforms.
Cross-bedding is stratification inclined to the original horizontal surface upon which the sediment accumulated. Ripple marks are sand waves produced on a top of a bed by wave or wind action. Hence, cross-beds may be used as indicators of ancient current directions. Ripple marks are undulations of the sediment surface produced as wind or water moves across sand. Giant Ripples of the Medina The Medina formation consists chiefly of red shale. In the type district, about Medina, New York, the thickness is about 800 feet, and there are beds of sandstone in the upper hundred feet.
Which one of the following is NOT a type of sedimentary structure? cross-bedding ripple marks mud cracks graded beds striations bedding planes 2.