Superficial deposits (or surficial deposits) refer to geological deposits typically of

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

age (less than 2.6 million years old) for the Earth. These geologically recent unconsolidated

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

s may include

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

channel and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

deposits, beach sands, talus gravels and

glacial A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

drift and

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a gla ...

. All pre-Quaternary deposits are referred to as

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bed ...

Types and history

There are several types of superficial deposit, including raised beaches and

brickearth Brickearth is a term originally used to describe Superficial deposits, superficial windblown deposits found in southern England. The term has been employed in English-speaking regions to describe similar deposits. Brickearths are periglacial ...

. These were formed in periods of climate change during the

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

s. The raised beaches were generally formed during periods of higher

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

, when ice sheets were at a minimum, and the sand and shingle deposits can be seen in many low cliffs. The brickearth is originally a wind-blown dust deposited under extremely cold, dry conditions but much has been re-deposited by flood water and mixed with

flint Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start ...

s. Superficial deposits were originally recorded only onshore and around the coast where they were laid down by various natural processes such as action by ice, water and wind. More recently offshore deposits have been mapped and may be separate sea-bed sediments. Most of these superficial deposits are unconsolidated sediments such as

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

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

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

, and onshore they form relatively thin, often discontinuous patches. Almost all of these deposits were formerly classified on the basis of mode of origin with names such as, 'glacial deposits', 'river terrace deposits' or 'blown sand'; or on their composition such as '

peat Peat is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. ''Sphagnum'' moss, also called peat moss, is one of the most ...

'. Geology databases contain information on the properties of superficial deposits. Geological survey houses these Geology databases. This information can be used for a number of different purposes in farming and forestry, including avoiding

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

, assessing growing conditions, gauging risks in terms of nutrient leaching and release of toxic substances, planning site preparation, road construction, felling and extraction operations, judging accessibility etc.

Geological Survey

Each

country A country is a distinct part of the world, such as a state, nation, or other political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, state with limited recognition, constituent country, ...

and is some countries each

state State most commonly refers to: * State (polity), a centralized political organization that regulates law and society within a territory **Sovereign state, a sovereign polity in international law, commonly referred to as a country **Nation state, a ...

province A province is an administrative division within a country or sovereign state, state. The term derives from the ancient Roman , which was the major territorial and administrative unit of the Roman Empire, Roman Empire's territorial possessions ou ...

has an organization with a superficial deposits database. Some of the geological survey are: *

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

California Geological Survey The California Geological Survey, previously known as the California Division of Mines and Geology, is the California state geology, geologic agency. History Although it was not until 1880 that the California State Mining Bureau, predecessor to ...

** Arkansas Geological Survey ** Arizona Geological Survey ** Delaware Geological Survey ** Oklahoma Geological Survey ** Indiana Geological and Water Survey ** Kansas Geological Survey ** Louisiana Geological Survey ** Utah Geological Survey ** Michigan Geological Survey ** Minnesota Geological Survey ** Pennsylvania Geological Survey ** Kentucky Geological Survey *

British Geological Survey The British Geological Survey (BGS) is a partly publicly funded body which aims to advance Earth science, geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. ...

Geological Survey of Sweden ''not to be confused with the Geologiska föreningen ()'' Geological Survey of Sweden (, SGU) is a Government agencies in Sweden, Swedish government agency that was founded by Axel Erdmann in 1858, that supervises all mineral deposits activities ( ...

* Geological Survey of Norway * Geological Survey of Finland * Mexican Geological Survey * Zimbabwe Geological Survey * Bureau de Recherches Géologiques et Minières - French Geological Survey *

Geological Survey of Canada The Geological Survey of Canada (GSC; , CGC) is a Canadian federal government agency responsible for performing geological surveys of the country developing Canada's natural resources and protecting the environment. A branch of the Earth Science ...

in French ''Géologie des formations superficielles du Canada''. ** Geological Survey of Newfoundland and Labrador ** Ontario Geological Survey ** Alberta Geological Survey * Geological Survey of Japan *

Geoscience Australia Geoscience Australia is a statutory agency of the Government of Australia that carries out geoscientific research. The agency is the government's technical adviser on aspects of geoscience, and serves as the repository of geographic and geolo ...

** Geological Survey of Western Australia ** Geological Survey of Queensland ** Geological Survey of South Australia **

Geological Survey of Victoria Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

References

{{DEFAULTSORT:Superficial Deposits Sedimentary rocks Sediments

Types and history

Geological Survey

See also

References