Facies

Body of rock with specified characteristic

In geology, a facies ( FAY-shih-eez, US also FAY-sheez; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formation) and the changes that may occur in those attributes over a geographic area. A facies encompasses all the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock.

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