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Ancient wave ripple marks in sandstone, Moenkopi Formation, Capitol Reef National Park, Utah In geology , ripple marks are sedimentary structures (i.e., bedforms of the lower flow regime ) and indicate agitation by water ( current or waves ) or directly by wind .
Bidirectional wave ripple, Nomgon, Mongolia. A paleocurrent or paleocurrent indicator is a geological feature (typically a sedimentary structure) that helps one determine the direction of flowing water in the geologic past. This is an invaluable tool in the reconstruction of ancient depositional environments. [1]
This creates ripple marks with pointed crests and rounded troughs, which aren't inclined more to a certain direction. Three common sedimentary structures that are created by these processes are herringbone cross-stratification, flaser bedding, and interference ripples. Asymmetrical ripple marks These are created by a one way current, for ...
Giant current ripple marks are large scale analogues of small current ripples formed by sand in streams. Giant current ripple marks are important features associated with scablands . As a landscape component, they are found in several areas that were previously in the vicinity of large glacial lakes.
Map of the Channeled Scablands. Bretz conducted research and published many papers during the 1920s describing the Channeled Scablands. His theories of how they were formed required short but immense floods – 500 cubic miles (2,100 km 3) – for which Bretz had no explanation.
Cross-beds are layers of sediment that are inclined relative to the base and top of the bed they are associated with. Cross-beds can tell modern geologists many things about ancient environments such as- depositional environment, the direction of sediment transport (paleocurrent) and even environmental conditions at the time of deposition.
Symmetrical ripple. Although symmetrical ripples are also called bi-directional ripples there is a difference between them. Bi-directional ripples are rarely symmetrical due to the difference in force of the two directions, where as the wave formed or oscillation ripples form from the circular water movement pattern of water molecules.
The next being an eraillure which is a flake that has been taken off of the lithic bulb of percussion. The third part of the flake is the radial fissures. The next part of the flake is the ripple marks followed by the negative flake scars which are located on the dorsal side from earlier flake markings.