Intraclasts are irregularly shaped grains that form by syndepositional

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

of partially lithified

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, san ...

Gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

grade material is generally composed of whole disarticulated or broken skeletal fragments together with

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of ...

grade material of whole, disaggregated and broken skeletal debris. Such sediments can contain fragments of early cemented

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...

s of local origin which are known as intraclasts. The sediments that contain fragments of early cemented limestones of extra-basinal origin are called extraclasts. Examples of intraclasts include mudlumps that are torn up from the bottoms of

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'' ...

s during storms, hardened desiccated mudflakes produced in

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species of ...

and supratidal environments and fragments broken from cemented deep-sea crusts. Other intraclasts are aggregates of carbonate particles. These include grapestones and botryoidal grains. Grapestones are composite grains with an irregular shape that resembles a bunch of grapes, whereas botryoidal grains are similar to oolitic coats enveloping the aggregate grains. These types of intraclasts form in shoal water environments with intermediate wave and current activity, where grains that are cemented on the sea floor are broken into aggregate fragments and lumps during storms.

References

Sedimentary rocks Limestone {{geology-stub