Sedimentaire gesteentes - Conglomerates

Page / - dernière modification par TerraIndex TerraIndex le 2021/09/30 15:18

Conglomerates

dernière modification par TerraIndex TerraIndex

le 2021/09/30 15:18

Table des matières

Conglomerate is a clastic sedimentary rock that contains large rounded clasts with a diameter from 2 mm to 63 mm. These clasts are poorly organized and present in a finer matrix. The lithology of the clasts and the matrix can be different from each other, but there is a possibility they are the same. Conglomerates mainly are formed in river areas. This rock type differs from breccia with its rounded clasts.

Origin

Sediments which are taken by a strong water current change shape because of the high energy level of the current. The shape of long and fast transported sediments becomes round and more flat shaped. The environment in which conglomerates are created must be a swiftly flowing stream or a beach with strong waves. To form a conglomerate, there must also be a source of large-size sediment particles somewhere up current. The rounded shape of the clasts reveals that they were tumbled for some distance by running water or moving waves. These conditions are found in streams and standing water bodies in many parts of the Earth. Conglomerates often begin when a sediment consisting mainly of pebble- and cobble-size clasts is being deposited. The finer-size sand and clay, which fill the spaces between the larger clasts, is often deposited later on top of the large clasts and then sifts down between them to fill the interstitial spaces. After compaction, the deposition of a chemical cement then binds the sediment into a rock.[1]

References

https://geology.com/rocks/conglomerate.shtml

Conglomerate

Group	Clastic sedimentary rock
Texture	Coarse-grained
Clasts	2 mm - 63 mm
Hardness	Varying much
Color	Varying much
Minerals	All kind of rock minerals
Touch	Rough but smoothed clasts
Image	Conglomerate image

Contents

Origin

References

Conglomerate