International Stratigraphic Guide
This reprint of the 1994 volume was produced at the request of the IUGS International Commission on Stratigraphy. The purpose of the 1994 volume was to promote international agreement on principles of stratigraphic classification and to develop an internationally acceptable stratigraphic terminology and rules of stratigraphic procedure. At the time of its first printing, this second edition was the most up-to-date statement of international agreement on concepts and principles of stratigraphic classification and a guide to international stratigraphic terminology. The first edition, published in 1976, was a significant contribution toward international agreement and improvement in communication and understanding among earth scientists worldwide. The revised, second edition updated and expanded the discussions, suggestions, and recommendations of the first edition, expansions necessitated by the growth and progress of stratigraphic ideas and the development of new stratigraphic procedures since release of the first edition.
Lithostratigraphic Units
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Published:January 01, 2013
Abstract
Lithostratigraphic units are bodies of rocks, bedded or unbedded, that are defined and characterized on the basis of their observable lithologic properties. All stratigraphic units are composed of rock and thus have “rock character,” but only lithostratigraphic units are differentiated on the basis of the kind of rock: limestone, sandstone, sand, tuff, claystone, basalt, granite, schist, marble, and so on. The recognition of such units is useful in visualizing the physical picture of the Earth's rocks, in working out rock sequences, in determining local and regional structure, in investigating and developing natural resources, and in determining the origin of rocks.
Lithostratigraphic units are the basic units of geologic mapping and are an essential element of the stratigraphy of the area. Lithostratigraphic classification is usually the first approach in stratigraphic work in any new area and is always an important key to geologic history even if no ages are available from either fossils or isotopic age determinations (Figure 3).