TillTill or glacial till is unsorted glacial sediment. Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines. Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes. Till is a form of glacial drift, which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice.
PeriglaciationPeriglaciation (adjective: "periglacial", referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing and freezing, very often in areas of permafrost. The meltwater may refreeze in ice wedges and other structures. "Periglacial" originally suggested an environment located on the margin of past glaciers. However, freeze and thaw cycles influence landscapes also outside areas of past glaciation. Therefore, periglacial environments are anywhere when freezing and thawing modify the landscape in a significant manner.
ColluviumColluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combination of these processes. Colluvium is typically composed of a heterogeneous range of rock types and sediments ranging from silt to rock fragments of various sizes. This term is also used to specifically refer to sediment deposited at the base of a hillslope by unconcentrated surface runoff or sheet erosion.
SiltationSiltation is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or permanent) of fine sediments on bottoms where they are undesirable. Siltation is most often caused by soil erosion or sediment spill. It is sometimes referred to by the ambiguous term "sediment pollution", which can also refer to a chemical contamination of sediments accumulated on the bottom, or to pollutants bound to sediment particles.
Sorting (sediment)Sorting describes the distribution of grain size of sediments, either in unconsolidated deposits or in sedimentary rocks. This should not be confused with crystallite size, which refers to the individual size of a crystal in a solid. Crystallite is the building block of a grain. Very poorly sorted indicates that the sediment sizes are mixed (large variance); whereas well sorted indicates that the sediment sizes are similar (low variance).
Marine sedimentMarine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles have their origins in soil and rocks and have been transported from the land to the sea, mainly by rivers but also by dust carried by wind and by the flow of glaciers into the sea. Additional deposits come from marine organisms and chemical precipitation in seawater, as well as from underwater volcanoes and meteorite debris.
Pelagic sedimentPelagic sediment or pelagite is a fine-grained sediment that accumulates as the result of the settling of particles to the floor of the open ocean, far from land. These particles consist primarily of either the microscopic, calcareous or siliceous shells of phytoplankton or zooplankton; clay-size siliciclastic sediment; or some mixture of these. Trace amounts of meteoric dust and variable amounts of volcanic ash also occur within pelagic sediments.
Sediment basinA sediment basin is a temporary pond built on a construction site to capture eroded or disturbed soil that is washed off during rain storms, and protect the water quality of a nearby stream, river, lake, or bay. The sediment-laden soil settles in the pond before the runoff is discharged. Sediment basins are typically used on construction sites of or more, where there is sufficient room. They are often used in conjunction with erosion controls and other sediment control practices.
Anti-gravityAnti-gravity (also known as non-gravitational field) is a hypothetical phenomenon of creating a place or object that is free from the force of gravity. It does not refer to the lack of weight under gravity experienced in free fall or orbit, or to balancing the force of gravity with some other force, such as electromagnetism or aerodynamic lift. Anti-gravity is a recurring concept in science fiction. Examples are the gravity blocking substance "Cavorite" in H. G.
TransportTransport (in British English) or transportation (in American English) is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipelines, and space. The field can be divided into infrastructure, vehicles, and operations. Transport enables human trade, which is essential for the development of civilizations.
