CROSS-BEDDING is a feature that occurs at various scales, and is observed in conglomerates and sandstones. Turbidity currents originate on the the slope between continental shelves and deep sea basins. Experiment has shown that a number of bedforms exist between certain values of flow strength, thus defining various bedform states. (2-D ripples) or may be trough-shaped, defining trough cross lamination (3-D ripples). Note also the geometry of the cross beds along different cuts relative to the flow direction and that these sinuous-crested bedforms result in trough cross-beds in the cut perpendicular to flow. Beach and Longshore Bar Cross-bedding. Evenly Laminated Sand and Horizontal Bedding. Upper plane bed results in planar stratification. Note also the geometry of the cross beds along different cuts relative to the flow direction and that these sinuous-crested bedforms result in trough cross-beds in the cut perpendicular to flow.
Cross-beds are the groups of inclined layers, and the sloping layers are known as cross strata. Cross bedding forms on a sloping surface such as ripple marks and dunes, and allows us to interpret that the depositional environment was water or wind. There are lots of subdivisions of cross stratification; different types represent different types of bedforms and different flow conditions. In contrast, the area between the separation point and the attachment point has very low flow. These tilted layers contained within larger layers are termed cross bedding. Here you see large cross-beds with curved bases sandwiched between layers with roughly horizontal laminations.
Trough cross bedding is produced by the downflow migration of lunate dunes in both subaqueous and subaerial environments. Cross-sectional view of ripple cross-laminated sandstone, showing bi-directional cross laminae indicative of a wave origin. Bedforms: features in sedimentary rocks formed by the interaction between flow and the sediment composing the bed. Straight crested dunes produce planar cross beds. Varying flow rates in a depositional setting can lead to both sand and mud being deposited at different times. Hummocky Cross Stratification (HCS) typically occurs when storm events deposit larger grained sediment between the storm weather wave base and the fair weather wave base which both refer to the location where energy from ocean waves typically meet the ocean floor. What is difference between geology and engineering geology?