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This makes it substantially important construction material in civil engineering projects. The sedimentary rock is formed by the settlement and subsequent cementation of mineral or organic particles on the floor of oceans or other collections of water. The application of sedimentary rock in civil engineering is discussed.
Contents: Types of sedimentary rocks Uses of Sedimentary Rocks 1. Building Construction 2. Structural Wall Construction 3. Cement Production 4. Sedimentary rocks are rocks made of lithified sediment. Sediments are grains of rocks, minerals, or mineraloids deposited on the surface of the earth.
Reflect on the rock cycle for an indication of the relationships between the rocks that erode to become sediments and sedimentary rocks. For sediment to become sedimentary rock, it usually undergoes burial, compaction, and cementation. Clastic sedimentary rocks are the result of weathering and erosion of source rocks, which turns them into pieces—clasts—of rocks and minerals.
Once they become pieces, these clasts are free to move away from their source rock and they usually do. They are most often transported by water and deposited as layers of sediment. The burial stage of lithification involves the deposition of more sediment layers top of those that had been deposited earlier. In a sedimentary basin where sediment is being deposited, it is common for subsidence lowering of the basin to be taking place, either because the crust and lithosphere beneath it are subsiding into the mantle to some extent, or because the surrounding uplands are undergoing uplift relative to the basin, or both.
This allows thousands of feet of burial, in some cases tens of thousands of feet of burial, to occur. As sediments are buried, the weight of overlying material exerts pressure, causing compaction of the sediments.
Lithostatic pressure packs the sediment grains closer together and reduces the porosity — space between the sediment grains. Examples include rock salt and other evaporite deposits. These sediments of salt crystals and other minerals form sedimentary rock without having to undergo burial and compaction.
During burial and compaction, sediments will undergo some amount of cementation. Cementation refers to the growth of new minerals between the sediment grains. These new minerals bind the sediment grains together.
One form of cementation is growth of quartz rims on the surfaces of pre-existing quartz grains in the sediment. This new mineral growth is a result of water in the pore spaces that dissolves and precipiates quartz. A second common cementing mineral is hematite, a red or rust-colored iron oxide mineral, which precipitates onto the sediment grains from a combination of dissolved iron and oxygen from water in the pore spaces.
A third common cementing mineral is calcite, which also precipitates from ions dissolved in the water in the pore spaces during lithification. Although there are other cementing minerals, quartz, hematite, and calcite are common cementing minerals that grow between or on the surfaces of the original sedimentary grains.
Grains of clastic sediment, which are called clasts are winnowed and modified during the weathering-to-deposition process. Weathering of minerals will gradually eliminate the physically weaker and chemically more reactive minerals, increasing the relative abundance of more resistant minerals.
Quartz tends to become increasingly abundant during the process, due to its common occurrence in the source rocks combined with its hardness and lack of cleavage, which makes it resistant to breaking down physically. Quartz is not easily dissolved or chemically altered, so it is resistant to breakdown by chemical reactions as well. That is why beach sand is often more rich in quartz than any other mineral.
Although feldspar is a fairly hard mineral, it does cleave split apart and is chemically reactive, especially in the presence of water. The most abundant product of chemical reaction of feldspar and water is clay minerals. During the erosion-to-deposition process, clastic sediments lose feldspar and gain a larger proportion of clay. Other minerals such as amphiboles, micas, and carbonates are relatively soft and chemically reactive and tend to be scarce or absent as sediment grains in mature clastic sediments, although calcite may be present in clastic sedimentary rocks as a secondary, cementing mineral that grew during lithification.
Minerals in chemical sedimentary rocks precipitate from water and usually remain in place or are not transported far before lithification. Such mineral sediments are subjected to little, if any, erosion and transportation. Therefore, the minerals in chemical sedimentary rocks are not winnowed during the weathering-to-deposition process as are the minerals in clastic sedimentary rocks.
In some cases, during the formation of chemical sediments, the minerals may change as a result of chemical reactions. For example, dolostone is a chemical sedimentary rock that forms in certain coastal environments by alteration of precipitated calcite to dolomite.
Besides minerals, mineraloid solids occur in some chemical sedimentary rocks. For example, the carbonaceous material in coal is an organic mineraloid rather than a mineral. Another example, opal, is a chemical sedimentary rock that does not have a fully developed crystal lattice and therefore is a mineraloid.
Figure 2. Sandstone is one of the common types of sedimentary rocks that form from sediments. There are many other types. Sediments may include:. Rocks at the surface undergo mechanical and chemical weathering. These physical and chemical processes break rock into smaller pieces.
Sediments are removed and transported by water, wind, ice, or gravity in a process called erosion Figure 2. Streams carry huge amounts of sediment Figure 3. For millions of years, a combination of heat and pressure created blocks of natural stone, including granite, marble, travertine, limestone, and slate.
Is Salt a mineral? Salt is a mineral consisting primarily of sodium chloride NaCl , a chemical compound belonging to the larger class of salts; salt in its natural form as a crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater, where it is the main mineral constituent. Where are rocks found? Geologists categorize rocks into three basic types, depending on their origin. Igneous rocks are formed by the cooling and solidification of magma molten rock in Earth's crust on or near the surface.
Sedimentary rocks, such as sandstone, are created by the compression of sediment or particles. What are 3 minerals found in a house? Carpet Calcium carbonate, limestone. Linoleum Calcium carbonate, clay, wollastonite.
Glossy paper Kaolin clay, limestone, sodium sulfate, lime, soda ash, titanium dioxide. How are minerals important in our lives? Just like vitamins, minerals help your body grow, develop, and stay healthy. The body uses minerals to perform many different functions — from building strong bones to transmitting nerve impulses.
Some minerals are even used to make hormones or maintain a normal heartbeat. What minerals are in water? Unlike regular drinking water, mineral water does not undergo chemical processing.
As the name suggests, mineral water contains high quantities of minerals, especially magnesium, calcium, and sodium. Minerals that are often present in mineral water include: calcium.
What are the properties of sedimentary rocks? What are sedimentary rocks like? Sedimentary rocks contain rounded grains in layers.
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