Planar Laminated Sandstone

Covered with a thin layer of plastic to protect it.

Planar laminated sandstone. Typically the undulation shows no evidence of lateral accretion but only vertical aggradation and as a result most beds consist of a single laminaset. B detail of wrinkled horizontal laminae. The depositional environment for this unit was slow settling i e fallout without traction. Sandstone beds are characterized by a peculiar planar lamination showing a subtle although perceptible undulation.

In geology lamination is a small scale sequence of fine layers laminae. Alternating episodes of deposition from high energy winds and. Lamina that occurs in sedimentary rocks laminae are normally smaller and less pronounced than bedding lamination is often regarded as planar structures one centimetre or less in thickness whereas bedding layers are greater than one centimetre. The planar laminated sandstone represents a dry sand sheet the surface of which would have been covered by granule wind ripples and climbing wind ripples.

Planar laminated sandstone ae2 and extensive flat bedded sandstone dominated by wrinkly laminae ae3 architectural elements. In geology cross bedding also known as cross stratification is layering within a stratum and at an angle to the main bedding plane. Consisting of several thin layers of. The original depositional layering is tilted such tilting not being the result of post depositional deformation cross beds or sets are the groups of inclined.

On parting surfaces through planar laminated sandstones parting lineation also called somewhat more precisely parting step lineation is characteristic presumably reflecting a tendency for flow parallel orientation of slightly elongated particles under upper flow regime conditions. Laminated light yellow to yellow colored parallel laminated sl sandstone in the middle and plannar cross stratified grayish white sandstone sp at the top chandimura section on lalmai hills. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The term parallel lamination has also been used to describe laminae with parallel but nonplanar boundaries figure p11.

The origin of planar lamination in sands and sandstones. The horizontally bedded sandstone represents a damp sand sheet the surface of which would have been covered by a microbial mat. Spacing to height ratios of the undulation are generally 100 or more. The sandstone is planar laminated and in some places ripples can be seen.

Planar laminated sandstones popularly known. Hence planar lamination has also been called horizontal lamination even lamination and parallel lamination. C d wrinkly laminations interbedded with isolated planar.