stratigraphic unit

A Dictionary of Earth Sciences | 1999 | 536 words | Copyright

stratigraphic unit A body of rock forming a discrete and definable unit. Such units are determined on the basis of their lithology (lithostratigraphic units), or their fossil content (biostratigraphic units), or their time span (chronostratigraphic units). It is unlikely that any rock succession will form a unit that accords with all three categories of classification. All stratigraphic units are defined by a type section. Geologic-time units are abstract concepts, not actual rock sequences, so do not class as stratigraphic units.

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AILSA ALLABY and MICHAEL ALLABY. "stratigraphic unit." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>.

AILSA ALLABY and MICHAEL ALLABY. "stratigraphic unit." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-stratigraphicunit.html

AILSA ALLABY and MICHAEL ALLABY. "stratigraphic unit." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-stratigraphicunit.html

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