Search results
Results from the WOW.Com Content Network
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.
Where the set height is less than 6 centimeters and the cross-stratification layers are only a few millimeters thick, the term cross-lamination is used, rather than cross-bedding. Cross-bed sets occur typically in granular sediments, especially sandstone , and indicate that sediments were deposited as ripples or dunes, which advanced due to 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.
In geology, lamination (from Latin lāmina 'thin layer') is a small-scale sequence of fine layers (pl.: laminae; sg.: lamina) that occurs in sedimentary rocks. Laminae are normally smaller and less pronounced than bedding .
Cross-bedding – the axis of a trough cross bed or the down-dip direction of a tabular cross bed point the direction of paleo flow. Current ripple marks – will have the short side of the ripple pointing down stream. Sole markings/flute casts – the short, steep side will point up stream, and the long, tapered side points down stream.
Types of beds include cross-beds and graded beds. Cross-beds, or "sets," are not layered horizontally and are formed by a combination of local deposition on the inclined surfaces of ripples or dunes, and local erosion. Graded beds show a gradual change in grain or clast sizes from one side of the bed to the other. A normal grading occurs where ...
The Des Moines Register in an unprecedented move for transparency has put online our cross tabs our weighting system and my analysis that I’ve not needed to update because it was pretty complete ...
Flaser bedding, vertical cross section. If the amount of deposited sand exceeds mud deposits, we get ripples with isolated mud drapes in ripple troughs and crests. This type of sedimentary structure is called flaser bedding. Flaser bedding can be subdivided according to how the mud is deposited over the rippled sand.