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Deposition can also refer to the buildup of sediment from organically derived matter or chemical processes. 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.
Examples include burrows and various expressions of bioturbation. Ichnofacies are groups of trace fossils that together help give information on the depositional environment. In general, as deeper (into the sediment) burrows become more common, the shallower the water. As (intricate) surface traces become more common, the water becomes deeper.
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.
The most ancient example of biomineralization, dating back 2 billion years, is the deposition of magnetite, which is observed in some bacteria, as well as the teeth of chitons and the brains of vertebrates; it is possible that this pathway, which performed a magnetosensory role in the common ancestor of all bilaterians, was duplicated and ...
Rhythmic cycles of deposition in sedimentary rock in Becquerel Crater, captured by the High Resolution Imaging Science Experiment camera on the Mars Reconnaissance Orbiter Cyclic sediments (also called rhythmic sediments [ 1 ] ) are sequences of sedimentary rocks that are characterised by repetitive patterns of different rock types ( strata ...
The older country rock is crosscut by a younger magmatic body. The nature of the intruding body depends on its composition and depth. Common examples are igneous dikes, sills, plutons, and batholiths. Depending on the composition of the magma, the intrusive body may have a complex internal structure which can provide insight into its emplacement.
After deposition, sediments are compacted as they are buried beneath successive layers of sediment and cemented by minerals that precipitate from solution. Grains of sediment, rock fragments and fossils can be replaced by other minerals (e.g. calcite, siderite, pyrite or marcasite) during diagenesis.
An example of a primitive rock is the achondritic iron-nickel octahedrite mineral seen in the Widmanstätten pattern that is found in a number of iron-rich meteorites.