clastic structure

In geology, clastic structures refer to features within rocks that are formed from the accumulation of fragments or the rupturing and dislocation of solid material. These structures are particularly characteristic of terrigenous clastic sedimentary rocks, which are composed of detrital fragments from pre-existing rocks and minerals.12

These rocks are classified based on the size of their constituent grains. Coarse clastic sediments include conglomerates (rounded fragments) and breccias (angular fragments). Sandstones are medium-grained clastic sediments, and finer-grained rocks include siltstones and claystones, collectively known as mudrocks. Clastic rocks often form wedge-shaped deposits adjacent to landmasses, known as clastic wedges, which can become very thick due to the accumulation of eroded terrestrial materials.23