Acting on the initiative of the Deputy Ministry of Mineral Resources (DMMR) for the creation of the Saudi Stratigraphic Committee (SSC), which was mandated to create and maintain a unified Saudi Arabian Stratigraphic Code based on international practice, the Ministry of Petroleum and Mineral Resources of the Kingdom of Saudi Arabia appointed its first members in 1977. The Saudi Stratigraphic Committee was reactivated by the Saudi Geological Survey (SGS) in 2001 and since then chaired by the SGS President. The committee is composed of representatives from Saudi Aramco, King Abdulaziz University, King Saud University, King Fahd University, King Abdulaziz City for Science and Technology, and Ministry of Water and Electricity. The first version of the Stratigraphic Code was published as DGMR TM-1979-1 which was applied only within the Directorate General of Mineral Resources and other related agencies working for it. These regulations contained no element of obligation to be used as a national code, although the interests of uniformity and ease of communication would have been clearly best served if they were followed. The Code was re-issued with significant modifications in 2004, as Data-File Report SGS-DF-2004-7 of the Saudi Geological Survey. That version was based mainly on the International Stratigraphic Guide (Salvador, 1994) and the North American Stratigraphic Code (1983), in addition to modifications designed to make it as suitable as possible for application in Saudi Arabia and particularly, in the highly contrasting settings of the mostly Precambrian terrains of the Arabian Shield and the surrounding Phanerozoic cover rocks. In this edition, procedures, definitions, classification, nomenclature and other provisions were adopted from the North American Stratigraphic Code (The North American Commission on Stratigraphic Nomenclature, 2005) and International Stratigraphic Guide (ISSC, 1994). Categories of formal stratigraphic units fall into 3 classes. Lithostratigraphic, lithodemic, magnetopolarity, biostratigraphic, and pedostratigraphic units belong to class I, the rock-material category based on content, inherent attributes, or physical limits. Chronostratigraphic and polarity-chronostratigraphic units belong to class IIA, the material category used as standards for defining spans of geologic time. Non-material and temporal categories of class IIB include geochronologic, polarity-chronologic, diachronic, and geochronometric untis. Since the Code was intended to be flexible enough to provide changes and revisions, only lithostratigraphic and lithodemic units are included in this edition. As the Code evolves, other formal stratigraphic units may be added in future editions.
The significant modifications that were made in the second edition and that have been maintained in this third edition are as follows:
1. Separate provisions were made for (1) sedimentary, extrusive, and/or low-grade metamorphic rocks derived from them, and (2) intrusive and/or high-grade metamorphic rocks.
2. Provision was 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.
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 was made for units that can be traced through various metamorphic zones.
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, in order to facilitate possible formalization in the future, is emphasized.
6. Emphasis is therefore made that the regulations to be obligatory hereafter.
Halawani, M.A., Al-Duaiji, A.A., Bahabri, B.H., Basyoni, M.H., Al Dabbagh, M.E., Al Ramadan, K., Al Ajmi, H.F., Al Mahri, A.K. (Saudi Stratigraphic Committee Members), 2013, Saudi Arabian code of stratigraphic classification and nomenclature, First Edition: Special Publication SGS-SP-2012-2, 21 p.