Reissue of Saudi Arabian Code of Lithostratigraphic Classification and Nomenclature: Second Edition
The Deputy Minister for Mineral Resources, Ministry of Petroleum and Mineral Resources, Kingdom of Saudi Arabia, appointed a Stratigraphic Committee in October 1977 with terms of reference that included the creation and maintenance of a unified Saudi Arabian Stratigraphic Code based on international practice. The resultant Code, which was published in TM-1979-1, was preceded by Regulations that govern its use by the Directorate General of Mineral Resources and by the other operating units of the Deputy Ministry for Mineral Resources. These Regulations contain no element of obligation for other authors to use the Code, although the interests of uniformity and ease of communication would clearly best be served if they were to do so; provision is therefore made in the Regulations for the Committee to act in an advisory capacity for such authors on request. The Code is based on the principles detailed in the International Stratigraphic Guide (Hedberg, 1976) and in the national codes listed at the end of this manual, with modifications designed to make it as suitable as possible for application in Saudi Arabia and particularly in the mostly Precambrian terrane of the Arabian Shield.
The only significant changes that have been made in this second edition are as follows:
1- Separate provisions have been made for (1) sedimentary, extrusive, and (or) low-grade metamorphic rocks derived from them and for (2) intrusive and (or) high-grade metamorphic rocks. Some consequential changes have been made in the order and numbering of clauses in the Code.
2- Provision has been made for the use of the terms Member and Layer for divisions of units of intrusive and (or) high-grade metamorphic rocks of formational rank. Provision has also been made for the use of the terms Supersuite and Subsuite, in addition to Suite, for aggregates and subsets of suites of such units.
3- The inadmissibility of knowingly combining (1) sedimentary, extrusive, and (or) low-grade metamorphic rocks with (2) intrusive and (or) high-grade metamorphic rocks in any single unit is emphasized. Provision has been made for units that can be traced through various zones of metamorphism.
4- The requirement for a formal Group to have a type area has been removed.
5- The need for informal classification and nomenclature to follow the rules for formal classification and nomenclature as closely as possible, to facilitate possible future formalization, is also emphasized.
Comments on the Regulations and Code are welcome; they should be addressed to the Secretary, Stratigraphic Committee, Deputy Ministry for Mineral Resources, P.O. Box 345, Jiddah, 21411, Saudi Arabia.*
Stratigraphic Committee, 1984, Saudi Arabian code of lithostratigraphic classification and nomenclature: Second edition: Saudi Arabian Deputy Ministry for Mineral Resources Technical Manual DM-TM-04-1 Reissued as Saudi Geological Survey Data-File Report SGS-DF-2004-7, 16 p.