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The Rock Cycle

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The rock cycle basic definiton  is transitions among the three main rock types, which are metamorphic, igneous and sedimentary rocks. Each of the rocks can be altered when they are force out equilibrium conditions.The rock cycle describes how the three rock types are interrelated and how processes change from one to another over time.

Diagram describing the rock cycle
Diagram describing the rock cycle

Rock Cycle Processes

Igneous Rock Cycle Process

When rocks are pushed deep under the surface, they can melt into magma. If the conditions for the magma to remain liquid are no longer present, they are cooled and incorporated into an igneous rock. A rock that cools in the earth is called intrusive or plutonic, and it cools very slowly to produce a coarse-grained texture, such as rock granite. As a result of volcanic activity, the magma (called lava when it reaches the Earth’s surface), which is called extruded or volcanic rocks, can cool down very quickly while on the surface where the Earth is exposed to the atmosphere. These rocks are fine grained and sometimes so fast that no crystals form and do not result in a natural glass like obsidian, but the most common fine grained rock is known as basalt. Any of the three main rock types (igneous, sedimentary and metamorphic rocks) can melt into magma and cool down to igneous rocks.

Crystallization: The magma cools underground or on the surface and cures to a rickety rock. As the magma cools, different crystals form at different temperatures that undergo crystallization. For example, mineral olivine crystallizes at temperatures much higher than quartz than magma. The cooling rate determines how much time the crystals must form. Slow cooling produces larger crystals.

Rock Cycle
Rock Cycle

Metamorphic Rock Cycle Process

Metamorphic rocks can be changed physically or chemically to form a different rock under the high pressures and temperatures. Regional metamorphism refers to effects on large rock masses over a large area, usually associated with mountain formation events in orogenic belts. These rocks exhibit different bands of different mineralogy and colors, often called foliation. Another main type of metamorphism occurs when a rock mass comes into contact with an igneous intrusion that heats up this surrounding country rock. This contact metamorphism results in an over temperature of the magma and / or a rock which is altered and recrystallized by the addition of liquids that add chemical material (metasomatism) to the surrounding rock. Any pre-existing rock species can be replaced by metamorphism processes.

Metamorphism: When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes metamorphosed. Metamorphism can change the mineral composition and the texture of the rock. Thus, a metamorphic rock can be a new mineral composition and / or texture.

Sedimentary Rock Cycle Process

Rocks exposed to the atmosphere are variably unstable and subject to weathering and erosion. Abrasion and erosion break down the original rock into smaller pieces and remove dissolved materials. This shredded material accumulates and is embedded by additional material. While an individual sandstone is still a member of the rock class from which it is formed, it is a rock sediment composed of mixed grains. Sedimentary rocks may consist of collection of these small fragments (plastic clastic rock), accumulation and lithification of living organisms, or removal of mineral sediment from biologically deposited material. evaporation (sedimentary sedimentary rock). Due to processes such as plant residues, such as elastic or organic material, frangible fractions may form from fragments separated from larger rocks of any species. Biogenic and sedimentary rocks consist of accumulation of minerals from dissolved chemicals from all other rock types.

Erosion and Sedimentation: Attrition, rock glides into smaller pieces on the surface of the Earth. Small pieces are called sediments. Flowing water, ice and gravity transport these deposits from one place to another by erosion. During sedimentation, sediments are laid or deposited. In order to form a sedimentary rock, the accumulated sediment must be compacted and cemented together.

The Rock Cycle Chart
The Rock Cycle Chart

Several processes can turn one type of rock into another type of rock. The key processes of the rock cycle are crystallization, erosion and sedimentation, and metamorphism.

Where does the energy that drives Earth’s rock cycle come from? Processes driven by heat from Earth’s interior are responsible for creating igneous and metamorphic rocks. Weathering and erosion, external processes powered by energy from the Sun, produce the sediment from which sedimentary rocks form.

Cite this article as: Mahmut Mat, "The Rock Cycle", in Geology Science, [online] Accessed 17th July 2019, Available at: http://geologyscience.com/general-geology/the-rock-cycle/
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