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This process results in roughly spherical concretions that grow with time. In the case of pervasive growth, cementation of the host sediments, by infilling of its pore space by precipitated minerals, occurs simultaneously throughout the volume of the area, which in time becomes a concretion. Concretions are often exposed at the surface by ...
Cementation is continuous in the groundwater zone, so much so that the term "zone of cementation" is sometimes used interchangeably. Cementation occurs in fissures or other openings of existing rocks and is a dynamic process more or less in equilibrium with a dissolution or dissolving process.
In sedimentology, compaction is the process by which a sediment progressively loses its porosity due to the effects of pressure from loading. This forms part of the process of lithification . When a layer of sediment is originally deposited, it contains an open framework of particles with the pore space being usually filled with water.
Cementation may refer to: Cementation (biology) , the process whereby some sessile bivalve mollusks (and some other shelled invertebrates) attach themselves permanently to a hard substrate Cementation (geology) , the process of deposition of dissolved mineral components in the interstices of sediments
Soil structure affects aeration, water movement, conduction of heat, plant root growth and resistance to erosion. [26] Water, in turn, has a strong effect on soil structure, directly via the dissolution and precipitation of minerals, the mechanical destruction of aggregates [27] and indirectly by promoting plant, animal and microbial growth.
Cementation of copper is a common example. Copper ions in solution, often from an ore leaching process, are precipitated out of solution in the presence of solid iron . The iron oxidizes, and the copper ions are reduced through the transfer of electrons.
For example, in lithic sandstones, cementation is less extensive because pore space between framework grains is filled with a muddy matrix that leaves little space for precipitation to occur. This is often the case for mudrocks as well. As a result of compaction, the clayey sediments comprising mudrocks are relatively impermeable.
The particulate matter then undergoes compaction and cementation at moderate temperatures and pressures . [ 5 ] : 265–280 [ 15 ] : 147–154 Before being deposited, sediments are formed by weathering of earlier rocks by erosion in a source area and then transported to the place of deposition by water , wind , ice , mass movement or glaciers ...