Petrographic code of Russia

The Petrographic Code of Russia is a body of major rules and recommendations that establish a unified and standardized petrographic terminology and nomenclature for endogenic and impact rocks and the taxonomy of petrographic units. The single system of terms and concepts underlying the petrographic code shall be obligatory for all departments and organizations in conducting geological operations in the territory of Russia. This system shall be applied when state geological maps of various scales and series legends for them are prepared and when maps are created under international projects. The structure of the second and third editions of the Code was modified compared with that of the first edition, and this edition includes new appendices. With regard for new standards and requirement of geological practice, additional sections concerning sedimentary-volcanic, migmatite, and some other rocks were introduced into the Code. The sections devoted to metamorphic and metasomatic rocks were revised and amended, and arguments were proposed justifying the recognition (as an individual genetic type) of fluid-explosion rocks, which can be accompanied by ore mineralization of various types. Most definitions are revised, many entries are reworked and or abridged, and new entries are added. The revised wording of the Code involves recommendations from the International Commission on Systematics in Petrology of the International Unit of Geological Sciences.