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Lithostratigraphy is a sub-discipline of
There are a number of principles that are used to explain the appearance of stratum. When an igneous rock cuts across a formation of sedimentary rock, then we can say that the igneous intrusion is younger than the sedimentary rock.
A lithostratigraphic unit conforms to the
Lithostratigraphic units are recognized and defined on the basis of observable rock characteristics. The descriptions of strata based on physical appearance define
Stratotype: A designated type of unit consisting of accessible rocks that contain clear-cut characteristics which are representative of a particular lithostratigraphic unit.
The fundamental Lithostratigraphic unit is the