Friday, November 15, 2013

Three Natural Forces Affecting Rocks

Rocks are constantly broken down and remade.


Rocks are always morphing into different types of rocks. In the 18th century, James Hutton (known as the founder of modern geology) observed that rocks are profoundly impacted by the forces of nature. Heat, pressure and erosion affect how rocks develop, break down and are recreated.


The Rock Cycle


"The Rock Cycle" is a term used by Hutton to describe the cycle when rocks are made and broken down. It reveals a process of large rocks eroding into dirt, dirt compressing into rock and heat and pressure forging the cycle of new rocks.


Heat


The Earth's crust moves and rocks are pulled under and then ejected out. When rocks become submerged below the surface of the Earth, they are exposed to hotter temperatures. Most rocks melt when they are between 60 and 125 miles underground. The deeper underground they are, the hotter the rocks get. Rocks between 1100 and 2400 degrees Fahrenheit transform into a molten state known as magma.


Pressure


Rocks receive pressure from tons of other rocks pressing down on them when they are beneath the surface of the earth. Pressure, in combination with heat, significantly transforms rocks through a process known as metamorphism. Rocks affected by both heat and pressure are known as metamorphic rocks.


Erosion/Weatherization


Wind, sun and climate change create erosion, a natural force that breaks down rock into sediments. Erosion affects all rocks on the earth's surface. The elements of wind and water can change landscapes and move mountains. Erosion always occurs from the top down; this is mass wasting. It is a displacement of matter from one place to another. Rocks affected by erosion and weatherization break into new pieces of rock known as sedimentary rock.







Tags: broken down, heat pressure, Rock Cycle, Rocks affected, when they