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A diagram of various depositional environments. In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock record.
For example, chalk is made up partly of the microscopic calcium carbonate skeletons of marine plankton, the deposition of which induced chemical processes to deposit further calcium carbonate. Similarly, the formation of coal begins with the deposition of organic material, mainly from plants, in anaerobic conditions.
One example of deposition is the process by which, in sub-freezing air, water vapour changes directly to ice without first becoming a liquid. This is how frost and hoar frost form on the ground or other surfaces. Another example is when frost forms on a leaf. For deposition to occur, thermal energy must be removed from a gas.
In chemistry, deposition occurs when molecules settle out of a solution. Deposition can be defined as the process of direct transition of a substance from its gaseous form, on cooling, into a solid state without passing through the intermediate liquid state.
Molecular-beam epitaxy takes place in high vacuum or ultra-high vacuum (10 −8 –10 −12 Torr).The most important aspect of an MBE process is the deposition rate (typically less than 3,000 nm per hour) that allows the films to grow epitaxially (in layers on top of the existing crystal).
Marine biogenic calcification is the biologically mediated process by which marine organisms produce and deposit calcium carbonate minerals to form skeletal structures or hard tissues. This process is a fundamental aspect of the life cycle of some marine organisms, including corals , mollusks , foraminifera , certain types of plankton , and ...
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Sputter-coated ant specimen (Aulacopone relicta) for SEM examination.. Sputter coating in scanning electron microscopy is a sputter deposition process [clarification needed] to cover a specimen with a thin layer of conducting material, typically a metal, such as a gold/palladium (Au/Pd) alloy.