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Sand dune cross-beds can be large, such as in the Jurassic-age erg deposits of Navajo Sandstone in Canyonlands National Park. Aztec Butte shown here Formation of cross-stratification Schematic of eolian cross-bedding Close up of cross-bedding and scour, Logan Formation, Ohio Tabular cross-bedding in the Navajo Sandstone in Zion National Park Tabular cross-bedding in the South Bar Formation in ...
Hummocky cross-stratification from the Book Cliffs, Utah. Hummocky cross-stratification from the Arisag Formation (Silurian), Nova Scotia. Hummocky cross-stratification is a type of sedimentary structure found in sandstones. It is a form of cross-bedding usually formed by the action of large storms, such as hurricanes. It takes the form of a ...
Cross-bedding and scour in a fine sandstone (Logan Formation, Mississippian, Jackson County, Ohio) A teepee structure in modern halite deposits along the western shore of the Dead Sea, Israel. These structures are within sedimentary bedding and can help with the interpretation of depositional environment and paleocurrent directions. They are ...
A bedding surface is three-dimensional surface, planar or curved, that visibly separates each successive bed (of the same or different lithology) from the preceding or following bed. Where bedding surfaces occur as cross-sections, e.g., in a 2-dimensional vertical cliff face of horizontal strata, are often referred to as bedding contacts .
Wavy bedding occurs when mud is deposited over the whole area of a bed of rippled and/or cross stratified sand. It usually loosely follows the alternating concave-convex nature of the ripples creating a wavy appearance. In wavy bedding the ripples are laterally discontinuous. Wavy bedding marks the boundary between flaser and lenticular bedding ...
Very small cross-lamination means that the ripple height is roughly one centimeter. It is lenticular, wavy and flaser lamination. Small Small cross-bedding are ripples set at a height less than ten centimeters, while the thickness is only a few millimeters. Some ripples that may fit this category are wind ripples, wave ripples, and current ripples.
The Beacon Supergroup is a geological formation exposed in Antarctica and deposited from the Devonian to the Triassic). The unit was originally described as either a formation or sandstone, and upgraded to group and supergroup as time passed. It contains a sandy member known as the Beacon Heights Orthoquartzite. [1]
Organic sedimentation of parent material from decaying plant matter in bogs or swamps can also result in a graded bedding complex. This activity leads to formation of peat or coal, after thousands of years. Limestone is more than 95% biogenic in origin. It is made from the deposition of carbonate fossils of marine organisms. Bio erosion caused ...