Terminology Debate

Earth Scientists interested in standardizing of Sequence Stratigraphy are encouraged to contribute to this process by submitting constructive documentation to this site. Submissions should be sent to seqstrat@gmail.com as text or word files.

The Sequence stratigraphic approach to the interpretation of the sedimentary section started in the mid 70's (Vail et al 1977). This and other papers from this group of Exxon geologists immediately prompted discussion on the geologic value of Sequence Stratigraphy and its inter-relationship with earlier approaches to stratigraphic interpretation.  Influenced by these papers and other literature on the topic Ashton Embry and Octavian Catuneanu become prosletizers and critics of how best to apply Sequence Stratigraphy.  Since then at least two groups of earth scientists developed with different perspectives on the formalization of Sequence Stratigraphy in terms of methodology, Surfaces, units and terminology.

These groups are:
  • The IWGSS (International Working Group on Sequence Stratigraphy) founded by Octavian Catuneanu in 2006. The group is comprised of Octavian Catuneanu, Vitor Abreu, Janok Battachariya, Mike Blum, Robert Dalrymple, Pat Eriksson, Chris Fielding, William Fisher, Bill Galloway, Martin Gibling, Kate Giles, John Halbrook, Robert Jordan, Christopher Kendall, Ole Martinsen, Andrew Miall, Jack Neal, Henry Posamentier, Brian Pratt, Keith Shanley, Ron Steel, and Charles Winker.
  • The International Subcommission on Stratigraphic Classification (ISSC) Task Group on Sequence Stratigraphy was appointed in 2007 by Dr Maria Cita. This is comprised of Ashton Embry, Erik Johannesen, Donald Owen, Benoit Beauchamp and Piero Gianolla.
The history of the dialogue between these two groups from 2007 through 2008 onward can be seen in the correspondence below and reports on the meeting of the ISSC at the 33rd International Geological Congress (IGC), Oslo, Norway, in August of 2008. Details of this meeting are in ISSC Newsletters placed on line at the University of Milan by Maria Cita. Also available are  "on line streaming lectures" and "Power Point" presentations on this topic and other topics related to Sequence Stratigraphy. Links to of the power point presentations given at the IGC are can be accessed here too!

Both groups are reviewing the Sequence stratigraphic literature and making recommendations regarding the methods and terminology of Sequence Stratigraphy. The ISSC Task Group plans to publish their results in a revised edition of the International Stratigraphic Guide (ISG). The North American Commission on Stratigraphic Nomenclature (NACSN) will evaluate feedback from both the IWGSS and the ISSC reports in preparation for an upgraded version of the North American Stratigraphic Code.

Toward the Formalization of Sequence Stratigraphy (IWGSS)
Sequence Stratigraphy as a “Concrete” Stratigraphic Discipline (ISSC)

The first two posted pdf files above are circulated first drafts and outline the initial positions of the two groups and It would be misleading to suggest these are set in stone. The three pdf documents below represent the first comment from Octavian Catuneanu on the ISSC report, Ashton Emry's response and his short history of the orgin of the groups. Scientific critiques of the reports and subsequent documents from other Earth Scientists comments will be posted as text documents while longer responses and/or illustrations will be posted as pdf's. One objective of this page is that these comments should help the authors revise their manuscripts and positions.

Reply to ISSC Report

Comment on Reply

Brief History of Reports
Comment on ISSWG Report
Comment on ISSC Report

"Shoehorning in Sequence Stratigraphy and its ConSequences" by Ashton Embry

ISSC's Position on Sequence Stratigraphy

Maria Cita, Emeritus Professor of Geology University of Milano, Honorary Fellow of GSA and Honorary Member of INQUA, chair of the Italian Commission on Stratigraphy and chair of the ISSC - the Subcommission of Stratigraphic Classification of the International Commission on Stratigraphy(IUGS) has or is developing guides to LithoStratigraphy, cycloStratigraphy, chemoStratigraphy, MagnetoStratigraphy, BioStratigraphy, and ChronoStratigraphy tied to the International Stratigraphic Guide.

Maria Cita is the guiding hand behind the current International Subcommission on Stratigraphic Classification (ISSC) Task Group on Sequence Stratigraphy, and she has asked that this web site place a statement related to her position on the current debate currently ongoing on the USC web site tied to Sequence Stratigraphy. She has suggested that this statement be direct and diplomatic, while encouraging the protagonists to channel their energies into a constructive ending to the current confrontation.

Maria recognizes that there is no unique approach to Sequence Stratigraphy that fits all settings or suits every stratigrapher. Her plan is that the ISSC produce a short annotated document that considers the major points of agreement and difference between the various Sequence stratigraphic schools. Her intent is that the ISSC document provides general guidelines (not rules) that review the simple, clear, reasonable concepts of Sequence Stratigraphy for the student and seasoned professional. She would like the document to include at least three examples, from different continents and different time slices, of real world application of the various concepts to Sequence Stratigraphy so the reader can see how to apply these schemes to their own stratigraphic setting. She would like this document to evolve into something the stratigraphic community will be able to stand by and use as a guide. Her intent is that the document would acknowledge that Sequence Stratigraphy has evolved but questions of "style" and interpretation still remain!
Click the link that follows to view earlier & current ISSC Newsletters

The attached minutes are of the deliberations of the ISSC meeting at the 33rd International Congress, Oslo, Norway. They record progress in understanding among the various proponents but the issues and conclusions of the meeting participants still remain controversial and may even be incorrect (see Octavian Catuneanu's comments to these minutes below). The minutes are posted here with the intent that they might be considered as a working agenda for a discussion among the SEPM friends of Sequence Stratigraphy at the coming AAPG Denver. As indicated above Earth Scientists interested in standardizing these criteria for Sequence Stratigraphy are encouraged to a contribute constructive discourse based on the issues and conclusions of the Oslo meeting. Submissions should be sent to seqstrat@gmail.com as text or word files.

Minutes of the ISSC Workshop on & New developments in stratigraphic classification
Andreas Strasser / Fribourg, Christopher Kendall/ Columbia, Maria Cita/ Milan, Brian Pratt/ Saskatoon
25 August 2008
“Minutes of the ISSC Workshop on “New developments in stratigraphic classification - Amended by Octavian Catuneanu”
16 September 2008
"Sequence Stratigraphy: Methodology and Nomenclature" is intended to provide a neutral platform for inclusion of Sequence Stratigraphy in international stratigraphic guides and codes. It is the result of ISSC support, guidance, and feedback throughout the process leading to publication.
November 2011
Christopher Kendall (Emeritus Professor of Geology University of South Carolina) serves as the moderator to this dialogue and posts comments online at this site. Contributors are expected to treat this issue as a scientific debate and should provide scientifically objective concepts. Comments are expected to be posted on the day of their acceptance. Communications will be filtered for unprintable, outrageous invective, and polemics or comments that drift from the point!

Debate - Dated and Chronological order