How is shale formed?

Answer

Shale forms from the pressure of layers of sediment compressing bits of silt that settle into the clay on the bottom of bodies of water. The compressed clay and silt become shale over time. Shale is a sedimentary rock.

Shale starts with bits of rock that erode off of larger rocks from contact with moving water and the weather. Very fine particles of feldspar, quartz, mica, pyrite and other minerals settle to the bottom of still bodies of water, such as swamplands, deep parts of the ocean and deep, still lakes. The fine rock particles mix with decaying organic matter into a mud. Because weathering is a continual process, new layers are always building up. The top layers press on the bottom layers with more and more pressure. When enough pressure builds up, the bottom layers become rock through a process called lithification. Lithification causes the thin layers that are characteristic of shale.

Shale is a soft rock that breaks easily. The color varies depending on the exact minerals that formed the shale. Red, green and black are some color variations. Geologists classify shale as a claystone due to the small size of the particles that form the rock. Shale is a common rock that makes up much of Earth's crust.

Q&A Related to "How is shale formed?"
Shale is sedimentary, and is normally formed at the bottom of bodies of water. It is today found on mountaintops sometimes, but that is because of the "pushing up" action
http://wiki.answers.com/Q/Where_is_shale_normally_...
Shale basins are large underground deposits of fined-grained sedimentary shale rock formed from silt and mud compacted over a very long time. Deposits are built up in layers, much
http://energy.about.com/od/drilling/a/Rise-Of-U-S-...
Shale rock is a type of sedimentary rock formed from clay that is compacted together by
http://www.chacha.com/question/how-is-'shale'-form...
Shale is formed as a result of many processes. The first process involves the weathering and erosion of existing silicate rock, usually igneous or metamorphic in nature, and what
http://answers.yahoo.com/question/index?qid=201303...
Explore this Topic
Shale forms from the pressure of layers of sediment compressing bits of silt that settle into the clay on the bottom of bodies of water. The compressed clay and ...
The major difference between shale and sandstone is the type of materials from which they are formed and the size of the particles. Shale is made primarily from ...
Shale is a sedimentary rock used in making; bricks, cement, concrete and ceramic products. The rock is formed when clay is compacted together by pressure, it ...
About -  Privacy -  Careers -  Ask Blog -  Mobile -  Help -  Feedback  -  Sitemap  © 2014 Ask.com