Deposit

views updated May 29 2018

Deposit

A deposit is an accumulation of earth materials, usually loose sediment or minerals, that is laid down by a natural agent. Deposits are all around you the sand on the beach, the soil in your backyard, the rocks in a mountain stream. All of these consist of earth materials transported and laid down (that is, deposited) by a natural agent. These natural agents may include flowing water, ice, or gusts of wind (all operating under the influence of gravity), as well as gravity acting alone. For example, gravity alone can cause a rock fall along a highway, and the rock fall will form a deposit at the base of the slope. The agents of transport and deposition mentioned above are mechanical in nature and all operate in the same way. Initially, some force causes a particle to begin to move. When the force decreases, the rate of particle motion also decreases. Eventually particle motion ceases and mechanical deposition occurs.

Not all deposits form by mechanical deposition. Some deposits form instead by chemical deposition. All naturally occurring water has some minerals dissolved in it. Deposition of these minerals may result from a variety of chemical processes; however, one of the most familiar is evaporation. When water evaporates, dissolved minerals remain behind as a solid residue. This residue is a chemical deposit of minerals.

Ocean water is very rich in dissolved minerals that is why ocean water tastes salty. When ocean water evaporates, a deposit containing a variety of minerals accumulates. The mineral halite (that is, table salt) would make up the bulk of such a deposit. Large, chemically derived mineral deposits, which formed by the evaporation of ancient saline lakes, are currently being mined in several areas of the western United States. The Bonneville Salt Flats in Utah is a good example of an evaporite mineral deposit. Due to the arid climate, evaporite minerals are still being deposited today at Great Salt Lake in Utah.

The term deposit generally applies only to accumulations of earth materials that form at or near Earths surface, that is, to particles, rocks, or minerals that are of sedimentary origin. However, ore deposits are an exception to this generality. The phrase ore deposit applies to any valuable accumulation of minerals, no matter how or where it accumulates. Some ore deposits do form by mechanical or chemical deposition (that is, they are of sedimentary origin).

For example, flowing streams deposit gold-bearing sand and gravel layers, known as placers. Placers, therefore, form by mechanical deposition. Some iron ores, on the other hand, form when subsurface waters chemically deposit iron in porous zones within sediments or rocks. However, many ore deposits do not form by either mechanical or chemical deposition, and so are not of sedimentary origin.

See also Sediment and sedimentation.

deposit

views updated Jun 27 2018

de·pos·it / diˈpäzit/ • n. 1. a sum of money placed or kept in a bank account, usually to gain interest. ∎  an act of placing money in a bank account: I'd like to make a deposit.2. a sum payable as a first installment on the purchase of something or as a pledge for a contract, the balance being payable later: we've saved enough for a deposit on a house. ∎  a returnable sum payable on the rental of something, to cover any possible loss or damage.3. a layer or body of accumulated matter: the deposits of salt on the chrome. ∎  a natural layer of sand, rock, coal, or other material.• v. (-it·ed, -it·ing) 1. [tr.] put or set down (something or someone) in a specific place, typically unceremoniously: he deposited a pile of schoolbooks on the kitchen table. ∎  (usu. be deposited) (of water, the wind, or other natural agency) lay down (matter) gradually as a layer or covering: beds where salt is deposited by the tide. ∎  lay (an egg): the female deposits a line of eggs.2. [tr.] store or entrust with someone for safekeeping. ∎  pay (a sum of money) into a bank account: the money is deposited with a bank. ∎  pay (a sum) as a first installment or as a pledge for a contract: I had to deposit 10% of the price of the house.

Deposit

views updated May 23 2018

Deposit

A deposit is an accumulation of Earth materials, usually loose sediment or minerals , that is laid down by a natural agent. Deposits are all around you—the sand on the beach, the soil in your backyard, the rocks in a mountain stream. All of these consist of earth materials transported and laid down (that is, deposited) by a natural agent. These natural agents may include flowing water , ice , or gusts of wind (all operating under the influence of gravity), as well as gravity acting alone. For example, gravity alone can cause a rock fall along a highway, and the rock fall will form a deposit at the base of the slope. The agents of transport and deposition mentioned above are mechanical in nature and all operate in the same way. Initially, some force causes a particle to begin to move. When the force decreases, the rate of particle motion also decreases. Eventually particle motion ceases and mechanical deposition occurs.

Not all deposits form by mechanical deposition. Some deposits form instead by chemical deposition. As you may know, all naturally occurring water has some minerals dissolved in it. Deposition of these minerals may result from a variety of chemical processes; however, one of the most familiar is evaporation . When water evaporates, dissolved minerals remain behind as a solid residue. This residue is a chemical deposit of minerals.

Ocean water is very rich in dissolved minerals—that is why ocean water tastes salty. When ocean water evaporates, a deposit containing a variety of minerals accumulates. The mineral halite (that is, table salt ) would make up the bulk of such a deposit. Large, chemically derived mineral deposits, which formed by the evaporation of ancient saline lakes, are currently being mined in several areas of the western United States. The Bonneville Salt Flats in Utah is a good example of an "evaporite" mineral deposit. Due to the arid climate, evaporite minerals are still being deposited today at Great Salt Lake in Utah.

The term "deposit" generally applies only to accumulations of earth materials that form at or near the earth's surface, that is, to particles, rocks, or minerals that are of sedimentary origin. However, ore deposits are an exception to this generality. The phrase "ore deposit" applies to any valuable accumulation of minerals, no matter how or where it accumulates. Some ore deposits do form by mechanical or chemical deposition (that is, they are of sedimentary origin).

For example, flowing streams deposit gold-bearing sand and gravel layers, known as placers. Placers, therefore, form by mechanical deposition. Some iron ores, on the other hand, form when subsurface waters chemically deposit iron in porous zones within sediments or rocks. However, many ore deposits do not form by either mechanical or chemical deposition, and so are not of sedimentary origin.

See also Sediment and sedimentation.

deposit

views updated May 23 2018

deposit To place a value in a register in a processor, or in a word in memory. On many microprocessor or mini systems this can be achieved by manual operations on the control panel of the system.

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