In geology, the sedimentary structures known as cross-bedding are the (near-) horizontal units that are internally composed of inclined layers. This is a case in geology in which the original depositional layering is tilted, and the tilting is not a result of post-depositional deformation. These tilted layers contained within larger layers are termed cross bedding. Here you see three layers: a bottom massive layer (in geology, massive means lacking obvious structures), a middle layer 1 cm thick displaying perfect little cross-beds, and a top layer with gently inclined cross-beds. Formation of Cross Beds When a depositional environment has sand in it and water or air moves the sand grains around, those grains can build up into piles of sediment.
Within the major beds, cross-bedding is common. This structure is developed by the migration of small ripples, sand waves, tidal-channel large-scale ripples, or dunes and consists of sets of beds that are inclined to the main horizontal bedding planes. Cross bedding definition, having irregular laminations, as strata of sandstone, inclining in various directions not coincident with the general stratification. (geology) layering within one or more beds in a series of rock strata that does not run parallel to the plane of stratification Also called false bedding. Cross-bedding is stratification inclined to the original horizontal surface upon which the sediment accumulated. The photo on the left shows cross-bedding in sandstone.
(Geological Science) geology layering within one or more beds in a series of rock strata that does not run parallel to the plane of stratification. Also called: false bedding. In geology, the sedimentary structures known as cross-bedding refer to (near) horizontal units that are internally composed of inclined layers. Many of the Millstone Grit sandstones have preserved within them a series of low angled beds and bedding planes known as cross-bedding. These beds formed as sandbanks on the inside bend of a meandering river channel where water velocity was lower and finer sediment was deposited.
In the upper part of the lowest Molteno sandstone, deformed cross-bedding was observed at three localities. In general, dunes form by the migration of sediment up the stoss slope and down the lee slope, forming cross beds that are homologous to cross laminations. This particular sandstone displays some impressive cross-bedding. Posted in: Australia, cross-bedding, Monday Geology Picture, sandstone No Comments/Trackbacks. Nine main beds; infinite cross-beds, and also note the joint set orthogonal to the cross-beds. Hi, I am studying cross bedding at the moment in geology and was wondering if you could tell me how to do an annotated field sketch of this particular photograph- great photo by the way, thanks!. Definition of cross bedding The official Collins English Dictionary online. (geology) layering within one or more beds in a series of rock strata that does not run parallel to the plane of stratification Also called: false bedding. When one considers corroborating evidence such as carbon dating of the tissues consistently in the thousands of years, the cross bedding geology and areas with swirls of sediment in the deposition these better support the Flood model.