DEFINITION OF CLASTIC ROCKS

Sedimentary rocks that are composed primarily

of fragments of older rocks and minerals that have been

broken off from their parent rock, transported, and redeposited.

The word clastic is derived from the Greek word klastos,

meaning broken. The grain size is quite variable and may

include coarse-grained breccias and conglomerates, generally

deposited close to their source or in high-energy environments,

sandstones, siltstone, muds, and their metamorphic

equivalents. Clastic rocks are classified based on their texture,

composition of clasts and matrix, and on their grain size.

Grain size classifications are based on divisions known as the

Wentworth scale, named after Chester K. Wentworth

(1891–1969). The smallest particles in the Wentworth classification

are clay particles, with a diameter of less than 1/256

millimeter (.00015 inch). Silt particles range from clay-sized

to 1/16 millimeter (.0025 inch), sand from 1/16 to 2 millimeters

(.0025–0.079 inch), pebbles from 2 to 64 millimeters

(.079–2.5 inch), cobbles from 64 to 256 millimeters (2.5–10

inches), and boulders, larger than 256 millimeters.

See also FACIES; SEDIMENTARY ROCKS.

Title Post:
Rating: 100% based on 99998 ratings. 99 user reviews.
Author:

Terimakasih sudah berkunjung di blog SELAPUTS, Jika ada kritik dan saran silahkan tinggalkan komentar