The Code

The Commission’s chief publication is the North American Stratigraphic Code, or simply, the Code, with the current version dating to 2005. The Code serves as a guide to all stratigraphic practices throughout North America, and is foremost among the regional codes that influenced the nature, content, and stratigraphic philosophy of the International Stratigraphic Guide. Although all changes to the Code are finalized by the Commission, the terms of Article 21 allow any geoscientist to submit proposals for changes or additions. Feel free to do so at our Contact us form.

The Commission is continually updating the 2005 Code in response to new developments, with occasional revisions to entire sections. A recently completed program to improve the clarity of the Code included a complete revision of the “On Biostratigraphic Units” section. Discussions for emending the “Hydrostratigraphic Units” section is in progress and extensive discussions are planned on the relationship between “Allostratigraphy” and “Sequence Stratigraphy” - including whether there should be a separate “Sequence Stratigraphy Units” section.

To better serve the North American community, the Instituto de Geologia de Mexico published the Code in Spanish in 2010.


NACSN Notes have been a staple of the Commission since its inception. They cover any NACSN related topics, such as changes in nomenclature, meeting minutes, and, other news.

Most Commission reports and notes have been published courtesy of the Bulletin of the American Association of Petroleum Geologists, including Notes submitted at irregular intervals - ranging from Note 1 to the most recent Note 66. At this time, the Journal of Stratigraphy is the offiical publication venue for NACSN publications.

  • Set in Stone: The Work of the North American Commission on Stratigraphic Nomenclature

In 2009, the journal Stratigraphy published a special issue, Set in Stone: The Work of the North American Commission on Stratigraphic Nomenclature, that offers a comprehensive view of the Commission. Chapters include a full history of the Commission and the successive stages in development of the Code, advice on its use, discussions of the theoretical and practical issues of time and rock units that are addressed in the Code, and the articles of procedure.


AAPG Bulletin

GSA Bulletin