Learning About The Rock Cycle

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The rock cycle is a long process by which rocks are formed and reformed. All rocks go through this continual geological cycle. After the rocks go through the various phases, a new rock cycle begin again. Composed of different minerals and sediments, rocks are not classified as living things, even though they go through changes. The rock cycle starts with magma, then transitions to igneous rocks, sedimentary rocks, and metamorphic rocks. Upon reaching this stage, the rock melts back into magma, under specific conditions, and the cycle begins all over again.


The high temperature liquid material within the earth is known as magma, or molten rock. Magma contains gas bubbles and suspended crystals. Typically exiting the Earth from volcanoes and cracks in the Earth's crust, magma remains in its molten form until it hits the surface of the earth, when it becomes lava. The temperature of magma is measured to be between 1300 F and 2400 F. The exposure and cooling of magma is a crucial part of the rock cycle because it lays the ground work for the rest of the cycle to take place.


The crystallization process occurs after magma reaches the surface of the earth and turns into igneous rock. In this process, the materials including the suspended crystals inside the magma, harden together to form larger, more prominent crystals. When crystallization occurs on the surface of the rocks, magma is transformed into extrusive igneous rocks. Unlike crystallization that occurs in the crust, which turns magma into intrusive igneous rocks.


Weathering is the wearing down of rocks of any variety by natural forces, such as rivers, lakes, streams and oceans. There are two types of weathering, namely, mechanical and chemical. Mechanical weathering happens when a rock is broken down into smaller pieces without any altering of its mineral composition. For example, a rock of any variety that rolls down a hill and breaks into pieces can be classifies as mechanical weathering because it is essentially the same rock but is changed in form. In chemical weathering, the original composition of a rock is altered as a result of weathering. Chemical weathering creates new varieties of rock because it may combine elements of different rocks to form a unique geological specimen.


In the erosion-deposition system, deposition is the final stage. Deposition is the geological process whereby sand and sediments settle down on a surface. The transportation of rocks ends with deposition. Due to the fact that the earth has vast bodies of water, a lot of deposition occurs at the bottom of the ocean. Once a rock is deposited, it may form a metamorphic rock if the right conditions are applied to it, including intense heat and pressure.


Metamorphism is the process by which a rock changes into a different rock specimen. When a rock is subjected to changes in pressure, temperature or its base chemistry, metamorphism occurs. In particular, fluids and temperature have a big effect on rocks. For this reason, metamorphism is especially prevalent in the ocean or deep in the earth where enough pressure and heat can effect the make up of a rock and cause it to adapt to its' conditions.


Melting is the alpha and the omega of the rock cycle. It brings about the recrystallization of rocks into different rocks, as well as the formation of rock layers. In essence, magma is melted rock so it’s vital at the beginning of the cycle. At the end, a rock has to be melted first before it enters the rock cycle again.

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