Kansas Geological Survey
Stratigraphic Nomenclature Committee
April 2021

Committee Members

Evan Franseen, Tony Layzell, Greg Ludvigson, Diana Ortega-Ariza, Jon Smith (Chair), Julie Tollefson (Ex Officio)


The latest accepted stratigraphic guide and chart for Kansas was published over 40 years ago (D.E. Zeller, ed., 1968, The Stratigraphic Succession in Kansas: Kansas Geological Survey, Bulletin 189, 81p.). Since then, several journal papers, Kansas Geological Survey (KGS) Bulletins, a lexicon, and some unpublished stratigraphic charts have suggested or proposed changes to the classification and naming of stratigraphic units in Kansas, and updates and advances in stratigraphic positioning (including revised dates) and nomenclature that affect Kansas stratigraphy have been published. The new information and data that have been produced--along with questions, problems, and confusion generated by these changes--highlight the critical need for an updated, formally accepted stratigraphic guide and chart for Kansas.

Historically, formal stratigraphic guides, nomenclature, and charts for Kansas have been produced by the Kansas Geological Survey. In this regard, judgments are sought for formal guidance concerning Kansas stratigraphy by state, national, and international entities. The U.S. Geological Survey defers to each state to produce formal stratigraphic nomenclature, guides, and charts for their respective state.


The KGS has created the Stratigraphic Nomenclature Committee to address stratigraphic issues and establish formally accepted stratigraphic nomenclature for Kansas.

The KGS Stratigraphic Nomenclature Committee is to:

  • Continuously review, update, and standardize the stratigraphic nomenclature for Kansas. Duties include reviewing existing stratigraphic designations, problems, and proposed changes in stratigraphic positioning, classification, and naming of stratigraphic units in Kansas and advise the KGS Editor about appropriate use of stratigraphic nomenclature. The committee will formulate judgments and, when appropriate, produce peer-reviewed publications that revise and update stratigraphic issues for Kansas.
  • Develop and publish a new comprehensive formal stratigraphic guide and chart for Kansas.
  • Revise and update the Lexicon of Geologic Names of Kansas (KGS Bull. 231) after a new formal stratigraphic guide and chart have been published.

The Committee's work will be based on these principles:

  • Zeller (1968) is recognized as the most recent accepted stratigraphic guide and chart for Kansas.
  • Analysis and decisions concerning stratigraphic nomenclature in Kansas will follow the North American Code of Stratigraphic Nomenclature (2005) and any subsequent revisions.
  • The International Commission on Stratigraphy (ICS), a scientific body of the International Union of Geological Sciences (IUGS), is in the process of standardizing international stratigraphic nomenclature. The Committee will adopt the decisions of the IUGS-ICS as they apply to Kansas.
  • The Committee will solicit input from geoscientists within and outside the KGS who are knowledgeable about specific stratigraphic intervals or issues.
  • Committee members will be appointed by the State Geologist. The KGS Editor is an ex officio, non-voting member of the Committee.
  • The Committee will be the official arbiter of stratigraphic nomenclature and issues in Kansas; Committee decisions are final, subject to review by the State Geologist.