Sedimentary rocks like limestone and sandstone form through the accumulation and cementation of sediments. Metamorphic rocks like marble result from the alteration of pre-existing rocks due to high pressure and temperature. Igneous rocks such as basalt and granite originate from the solidification of molten material, with basalt associated with volcanic activity and granite forming from slow-cooling magma within the Earth's crust.
Sedimentary Rock:
- A. Limestone: Limestone is a sedimentary rock formed primarily from the accumulation of organic remains, such as shells and coral, or from the precipitation of minerals from water. The process involved is known as sedimentation, where these materials are compressed and cemented over time.
- B. Sandstone: Sandstone is another sedimentary rock that forms through the compaction and cementation of sand-sized grains. These grains may be derived from the erosion and breakdown of pre-existing rocks, transported by wind or water, and then deposited in layers.
Metamorphic Rock:
- D. Marble: Marble is a metamorphic rock that originates from the transformation of limestone or dolostone. The process, called metamorphism, involves the recrystallization of minerals due to high pressure and temperature. In the case of marble, the original calcite crystals in limestone are transformed into larger, interlocking crystals of calcite or dolomite.
Igneous Rock:
- C. Basalt: Basalt is an igneous rock that forms from the rapid cooling and solidification of magma or lava. It is typically associated with volcanic activity and can be found in areas such as mid-ocean ridges or as part of continental flood basalts.
- E. Granite: Granite is another igneous rock, but it forms from the slow cooling of magma deep within the Earth's crust. This slow cooling allows large crystals to develop, creating a coarse-grained texture. Granite is often associated with the continental crust and is a common component of many mountain ranges.