Varves Lamination Sedimentary Rock

Thus lamination consists of thin units in bedded or layered sequence in a natural rock succession whereas stratification consists of bedded layers or strata in a geologic sequence of interleaved sedimentary rocks.

Varves lamination sedimentary rock.

In its broadest sense the term is applied to the layer of sediment deposited in a single year. Varved deposit any form of repetitive sedimentary rock stratification either bed or lamination that was deposited within a one year time period. These types of lamination are attributed to successive deposits of layers. Sedimentology experiments on lamination of sediments resulting from a periodic graded bedding subsequent to deposition a contribution to the explanation of lamination of various sediments and sedimentary rocks.

In geology lamination is a small scale sequence of fine layers that occurs in sedimentary rocks. Laminae laminites varves etc. The word varve derives from the swedish word varv whose meanings and connotations include revolution in layers and circle. Any sedimentary rock composed of millimeter or finer scale layers can be named with the general term laminite.

A varve is an annual layer of sediment or sedimentary rock. A single sedimentary rock can have both laminae and beds. These sedimentation experiments have been conducted in still water with a continuous supply of heterogranular material. Initially varve referred to each of the separate components comprising a single annual layer in glacial lake sediments but at the 1910 geological congress the swedish geologist gerard de geer.

When sedimentary rocks have no lamination at all their structural character is called massive bedding. Lamination is often regarded as planar structures one centimetre or less in thickness whereas bedding layers are greater than one centimetre. This annual deposit may comprise paired contrasting laminations of alternately finer and coarser silt or clay reflecting seasonal sedimentation summer and winter within the year. More beds and the term lamina is sometimes applied to a unit less than one centimetre in thickness.

Laminae that represent seasonal changes similar to tree rings are called varves. Laminae are normally smaller and less pronounced than bedding. The term first appeared as hvarfig lera on the first map produced by the geological survey of sweden in 1862. A varve is an annual layer of sediment or sedimentary rock.

However structures from several millimetres to many centimetres have been described as laminae. Terms such as annually laminated are synonymous with varve. Of the many rhythmites found in the geological record varves are one of.