This forms granular, crystalline rocks. But sometimes, these rocks form without crystallization. Then the rocks formed are known as natural glasses. We can observe the occurrence of igneous rocks at a wide range of landforms such as shields, platforms, orogens, basins, extended crusts, ocean crusts, etc.
Moreover, most of the oceanic crusts on Earth are made of igneous rocks. Sedimentary rocks are a type of rocks that form via accumulation or deposition of sediment materials. This formation involves the deposition or accumulation followed by cementation with minerals or organic matter. These rocks form on the surface of the Earth.
Figure 2: Sedimentary Rock. The minerals for the cementation process are carried to a particular location by water, wind, ice, or mass movement. Organic matter for cementation is carried to the location via water flow in the form of piles. In addition, small scale sedimentation may occur due to the precipitation of sediment materials from water solution. Metamorphic rocks are a type of rocks that form from the transformation of an existing rock type into a new rock type.
We call this process metamorphism. A vote of thanks for bringing geography to our door steps. Thanks once more. I love this page it provides facts for us as learners so I will invite my fellows to follow this page.
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You agree that we have no liability for any damages. Igneous Rocks Igneous rocks are formed when magma or molten rocks cool down, and become solid.
Metamorphic Rocks Metamorphic rocks are the result of the transformation of other rocks. Author Recent Posts. Latest posts by Colleen see all. Help us improve. Rate this post! Cancel Reply. These sediments form as very thin layers. Then these layers become harder over a long period of time.
These hardened layers of sediments sedimentary rocks. The texture of sedimentary rocks reflects the mode of sediment deposition and subsequent weathering. Sedimentary rocks are easy to identify because of the visible layers. Most sedimentary rocks form under the water sea. Sedimentary rocks normally have pores since they form from sediments. Shale, sandstone, limestone, conglomerate, and coal are some examples of sedimentary rocks. These rocks are usually rich in fossils. Fossils are the remains of the animals and plants that are preserved in rocks.
Sedimentary rocks are present in a variety of colours. The key difference between igneous rocks and sedimentary rocks is that igneous rocks are formed from magma, while sedimentary rocks are formed from lithification of existing rocks. Igneous rocks are non-porous to water, while sedimentary rocks are porous to water. That is, water cannot penetrate through igneous rocks but can through sedimentary rocks.
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