List few examples of sedimentary rock state their uses and how they are for
Formation of Sedimentary Rocks All rocks, be it igneous, metamorphic, or the already existing sedimentary rocks are constantly subjected to weathering and erosion. Tiny debris from the rock masses and mountains are eroded together with soils, sand, and other granite pieces are normally washed from highlands to low areas. After many years, these materials finally settle down through the process of sedimentation. Some may accumulate under water and others on the lower areas of the land.
The weathering and erosion is normally due to the forces of water, thermal expansion, gravity, wind, and salt crystal expansion that breaks down the pre-existing rocks into small pieces and then carried away to some distance low areas. As the materials move, they are smoothened and rounded by abrasion, and they settle down by leaving pore spaces between the grains which make them achieve their distorted shape. At this point, they are deposited a layer after layer to form a new sheet of homogenous material. From here, the compaction and cementing agents such as oxides, carbonates, and silica combine together with the deposited material.
The compaction effect due to the weight of the piling layers of materials reduces the porosity of the rocks formed and intensifies the cohesion between the grains. At times, fossil fuels and organic matter may settle within the sediments leading to cementation. Cementation is the gluing of the rock pieces together either by salt compounds or organic matter. When these materials eventually harden, the mixture is transformed into a rock.
Thus, sedimentary rocks are formed from sediment deposits through the process of weathering, erosion, deposition and finally compaction and cementation. Examples of sedimentary rocks include mudstone, limestone, sandstone, and conglomerate.
Types of Sedimentary Rocks Sedimentary rocks are of three basic types. These include clastic, chemical, and organic sedimentary rocks.
- Clastic Sedimentary Rocks
Clastic sedimentary rocks are formed from the buildup of clatics: small pieces of fragmented rocks deposited as a result of mechanical weathering then lithified by compaction and cementation. Examples of Clastic sedimentary rocks include sandstone, shale, siltstone, and breccias.
- Chemical Sedimentary Rocks
Chemical sedimentary rocks are formed when the water components evaporate, leaving dissolved minerals behind. Sedimentary rocks of these kinds are very common in arid lands such as the deposits of salts and gypsum. Examples include rock salt, dolomites, flint, iron ore, chert, and some limestone.
- Organic Sedimentary Rocks
Organic sedimentary rocks are formed from the accumulation of any animal or plant debris such as shells and bones. These plant and animal debris have calcium minerals in them that pile on the sea floor over time to form organic sedimentary rocks. Examples include rocks such as coal, some limestone, and some dolomites.
Examples of Sedimentary Rocks As noted from the previous discussions, there are several types of sedimentary rocks. Here are the detailed examples of the various sedimentary rocks.
- Breccia
Brecia are clastic sedimentary rocks made up of angular rock broken parts that are cemented together. The angular shape means that the broken parts haven’t traveled far from their pre-existing materials. The broken pieces are similar to conglomerate because of their large pea-sizes. Breccias are commonly found along fault zones and they take any color.
- Conglomerate
Conglomerates are clastic sedimentary rocks composed of semi-rounded rock fragments cemented together. The rounded fragments depict that they have undergone abrasion and traveled a significant distant from their pre-existing materials. Conglomerates fragments are commonly deposited along the shoreline or stream channel and they are pea-sized or larger. They are also sometimes referred to as pudding stone.
- Siltstone Siltstones are composed of small-sized rock particles which are finer than sand grains but coarser than clay. It is among the clastic sedimentary rocks which are the most difficult to identify since it appears almost similar to fine-grained sandstone or a coarse shale. They normally occur in a wide variety of colors.
- Sandstone
Sandstones are clastic sedimentary rocks made up of cemented sand grains. Sandstones vary from fine-grained to coarse grained are readily distinguishable by the naked eyes. Mature sandstones or quartz sandstones are light-colored and majorly consist of rounded and well-sorted quartz grains. Graywackes or immature sandstones consist of angular grains of diverse minerals. Sandstones are generally white, red, gray, pink, black, or brown in color.
All rocks, be it igneous, metamorphic, or the already existing sedimentary rocks are constantly subjected to weathering and erosion. Tiny debris from the rock masses and mountains are eroded together with soils, sand, and other granite pieces are normally washed from highlands to low areas. After many years, these materials finally settle down through the process of sedimentation. Some may accumulate under water and others on the lower areas of the land.
The weathering and erosion is normally due to the forces of water, thermal expansion, gravity, wind, and salt crystal expansion that breaks down the pre-existing rocks into small pieces and then carried away to some distance low areas. As the materials move, they are smoothened and rounded by abrasion, and they settle down by leaving pore spaces between the grains which make them achieve their distorted shape.At this point, they are deposited a layer after layer to form a new sheet of homogenous material. From here, the compaction and cementing agents such as oxides, carbonates, and silica combine together with the deposited material.
The compaction effect due to the weight of the piling layers of materials reduces the porosity of the rocks formed and intensifies the cohesion between the grains. At times, fossil fuels and organic matter may settle within the sediments leading to cementation. Cementation is the gluing of the rock pieces together either by salt compounds or organic matter. When these materials eventually harden, the mixture is transformed into a rock.
Thus, sedimentary rocks are formed from sediment deposits through the process of weathering, erosion, deposition and finally compaction and cementation. Examples of sedimentary rocks include mudstone, limestone, sandstone, and conglomerate.
Types of Sedimentary RocksSedimentary rocks are of three basic types. These include clastic, chemical, and organic sedimentary rocks.
- Clastic Sedimentary Rocks
Clastic sedimentary rocks are formed from the buildup of clatics: small pieces of fragmented rocks deposited as a result of mechanical weathering then lithified by compaction and cementation. Examples of Clastic sedimentary rocks include sandstone, shale, siltstone, and breccias.
- Chemical Sedimentary Rocks
Chemical sedimentary rocks are formed when the water components evaporate, leaving dissolved minerals behind. Sedimentary rocks of these kinds are very common in arid lands such as the deposits of salts and gypsum. Examples include rock salt, dolomites, flint, iron ore, chert, and some limestone.
- Organic Sedimentary Rocks
Organic sedimentary rocks are formed from the accumulation of any animal or plant debris such as shells and bones. These plant and animal debris have calcium minerals in them that pile on the sea floor over time to form organic sedimentary rocks. Examples include rocks such as coal, some limestone, and some dolomites.
Examples of Sedimentary RocksAs noted from the previous discussions, there are several types of sedimentary rocks. Here are the detailed examples of the various sedimentary rocks.
- Breccia
Brecia are clastic sedimentary rocks made up of angular rock broken parts that are cemented together. The angular shape means that the broken parts haven’t traveled far from their pre-existing materials. The broken pieces are similar to conglomerate because of their large pea-sizes. Breccias are commonly found along fault zones and they take any color.
- Conglomerate
Conglomerates are clastic sedimentary rocks composed of semi-rounded rock fragments cemented together. The rounded fragments depict that they have undergone abrasion and traveled a significant distant from their pre-existing materials. Conglomerates fragments are commonly deposited along the shoreline or stream channel and they are pea-sized or larger. They are also sometimes referred to as pudding stone.
- Siltstone Siltstones are composed of small-sized rock particles which are finer than sand grains but coarser than clay. It is among the clastic sedimentary rocks which are the most difficult to identify since it appears almost similar to fine-grained sandstone or a coarse shale. They normally occur in a wide variety of colors.
- Sandstone
Sandstones are clastic sedimentary rocks made up of cemented sand grains. Sandstones vary from fine-grained to coarse grained are readily distinguishable by the naked eyes. Mature sandstones or quartz sandstones are light-colored and majorly consist of rounded and well-sorted quartz grains. Graywackes or immature sandstones consist of angular grains of diverse minerals. Sandstones are generally white, red, gray, pink, black, or brown in color.
