Deposition in chemistry refers to the process by which gaseous forms transform directly to solid form without passing through liquid form first, thus providing the opposite process from sublimation; think frost forming on windows!
Deposition is a natural geological process that transports sediment such as sand, silt and gravel from one location to the next. Water, wind, gravity or glaciers act as natural agents that influence how far this sediment travels; slower agents deposit closer to its point of origin.
Slate sediment is defined as loose organic or inorganic material that can be moved by water, wind, ice or gravity and includes soil fragments, dead organisms and decomposing plant material, as well as inorganic material like diatom frustules or calcium carbonate particles.
Sediments move according to shear stress, an equilibrium between their shear strength (“pulling”) and weakness (resisting), as well as sorting by size: silts and muds through sands to gravels and boulders; geologists who specialize in sedimentology study them extensively.
Sediment transport is one of the major causes of certain geologic features. Mountain streams carrying glacial sediments may transport them all the way to tidal bays where, over time, they harden into sandstone and limestone formations; create distinctive gulleys on volcanic islands like Hawaii; mix with salt to form rock salt formations at Bonneville Flats in Utah – to name just some of its many effects.
Erosion occurs when rocks and soil are worn away by natural forces such as wind or water, leading to their wear-and-tear by wind or water currents, such as wind. Erosion may be slow or fast depending on its environment; gently sloping hills do not erode as rapidly as steep mountains due to gravity’s pull on mountain sides, leading to landslides or glacier movement eroding their base rocks and creating more erosion.
Roots and vegetation help hold soil together, which reduces erosion. But when humans remove these plants through farming, ranching, or cutting down forests, erosion becomes more frequent. When water erodes away soil it often carries with it harmful chemicals, including pesticides and fertilizers into rivers and lakes which harms the environment further. Erosion also decreases soil’s ability to hold moisture and nutrients which decreases crop emergence, growth, yield and results in “nutrient depletion”.
Weathering is the process of breaking down rocks and minerals into smaller particles that can then be moved by erosion and deposited elsewhere, creating new landforms like mountains or beaches. Weathering can be caused by various forces including wind, water, ice, plants and the changing temperature of Earth’s surface.
Soil particles formed through weathering of rock are known as sediments, and can be carried from one location to the next by natural agents like water, wind or glaciers. The speed of each natural agent determines its effectiveness in transporting sediment; water has the capability of transporting silt further than wind does.
Deposition may also occur through gaseous materials. For instance, when warm air collides with very cold windowpanes it may condense directly into frost, known as sublimation – an opposite process from condensation which turns liquids back into gases.
From Year 4 (aged 8+), students gain knowledge about different states of matter and their transformation, including deposition.
Erosional agents such as water, wind or ice that have run out of energy to carry away sediment ultimately deposit it, creating layers of sand, gravel and silt and ultimately new landforms like mountains or beaches.
Passive transport involves moving ions or molecules along a concentration gradient without using energy from within the cell to do it, unlike active transport that relies on protein transporters to push these along.
Sublimation, also known as sublimation or direct solidification, occurs when gas changes directly to solid state without going through liquid phase first. It’s the opposite of melting and only happens at cold enough temperatures – Frost on windows is an example of sublimation; condensation also happens as substances cool off.