Report 2010-06

Meeting report - 09-06-2010

Present

Frieda Bogemans, Marie Coen-Aubert, Michiel Dusar, Luc Hance, Alain Herbosch, Vanessa Heyvaert, Piet Laga, Noël Vandenberghe, Johan Yans, Katrien De Nil

Excused

Eddy Poty, Frédéric Boulvain, Stephen Louwye, Jacques Verniers

1. Report of last NCS meeting (10-12-2009)

The President points out that point 2b : "Include an open forum page for each subcommission and insert there the units which didn't reach yet a consensus on a proposal to NCS" is going a step too far. NCS Members approved. There is ample room for discussion when the proposal is included as 'Proposal and Discussion ' to the website by the secretaries of the subcommissions.

2. General discussion

a. Comment from the President : when no consensus is reached on a proposal, who, inside a Subcommission is taking the final decision? Is it the "bureau" or the result of a vote amongst the members? It is demanded that the subcommission should reflect about this issue and comment on it during the next meeting.

b. Who are the Members of the subcommissions? The President finds it desirable that the list of active members is published on the website.

c. Not all subcommissions President and Secretary received their corresponding digital files of the 2001 volume. The NCS Secretary will make sure they get it asap.

3. Subcommission reviews.

a. Cambrian - Ordovician

This subcommission submitted an updated 2001 text (not the figures). The new units are included with their author names.

b. Devonian

A text regarding the Watissart and Brayelles Members has been submitted to update the 2001 volume.

A sentence to explain what is the meaning of the units listed on the website is required.

The work of Ben Laenen on the Devonian and Dinantian lithostratigraphy of the Campine Basin should be considered. This work is unpublished, but online on the DOV website (- Lithostratigrafie pré-Tertiair in Vlaanderen (opgedeeld in 3 pdf-rapporten): B. Laenen , Studie uitgevoerd in opdracht van ANRE (Vlaamse overheid; https://dov.vlaanderen.be/dovweb/html/2prekrijt.html). The work is mainly descriptive.

As the author can no longer devote the necessary time to this stratigraphical work, it is asked to Michiel Dusar to take an initiative to valorise this work. The president recommends that he evaluates together with the Devonian and Carboniferous subcommissions how it could be integrated in the global lithostratigraphical scheme. Katrien de Nil can be associated with this work and a link to the DOV website will be included on the NCS page.

a. Carboniferous

Reevaluation of the 2001 work led to the conclusion that several units have to be formalized:

  • The lateral equivalent of the Terwagne Formation in the southern part of the Dinant Synclinorium.
  • The Lower Visean of the Orneau and Ligne valleys.
  • The units of the Saint-Ghislain drillhole.
  • The problem of the Belle-Roche Breccia.
  • The dolomitized units
  • The Upper Westphalian lithostratigraphy…

A meeting of the subcommission will be organized soon.

b. Permian - Trias - Jurassic

Lithostratigraphy of the Lorraine was already announced to be finalized and should be submitted.

c. Cretaceous

1. The Strepy Fm is ratified by NCS.

To answer a question of the President, Johan Yans explains that the Saint-Pierre Fm (partly in the Haine Group) covers river sediments extending over 90 M years and was based on a single quarry. The Strepy Fm is equivalent to the upper part of the Saint Pierre Fm in the 2001 definition.

2. Lagrou, D. and Duasar, M. Have submitted a revision of the Vaals Fm. It concerns the Campine Basin where the formation has a twofold subdivision, the Sonnisheide Mbr (new) and Asdonk Mbr (new).

The status of the "Smectite de Herve" which was included in the Vaals Fm in the 2001 volume, without any stratigraphic status is debated by the President. According to Johan Yans, it is an alterite. Anyway, it is a lithologic unit which should receive a Member rank. The President recommends that the Cretaceous Subcommission includes a note on the webpage explaining better the status of the "Smectite de Herve".

A new name for the Hautrage bed (2001) will be introduced : Haine Saint-Pierre Fm. Indeed, Hautrage designates also an upper Turonian Fm of the Mons Basin.

d. Paleogene-Neogene

The text prepared in 2000 by S. Geets et al. (2000) is being revised . Some parts will be proposed soon on the website. For the Rupel Group a discussion note by F. Gullentops and will be available soon.

Michiel Dusar raised the question about the status of the Danian Houthem Formation as it is lithologically indistinguishable from the underlying Cretaceous calcarenites. It was suggested that the subcommission keeps this formation name for the Danian Houthem as long as no global name, of higher rank than the Houthem unit and grouping all calcarenites of the Cretaceous- Paleogene transition interval was introduced. Could be a common point for Cretaceous and Tertiary subcommissions.

The status of the Calcarenite of Maasmechelen should be clarified; this unit is an interval in the Opglabbeek Formation. It was considered a Member in Geets et al. (2000) and a 'calcareous zone' in the Eisden Member of the Opglabbeek Fm in the Geologica Belgica volume (2001).

e. Quaternary

A new table with the loess subdivision (Pirson, Haesaerts and Meijs) is submitted during the meeting. The text will follow.

4. Varia

a. 4ème Congrès Français de Stratigraphie (August 30 - September 2/2010)

The President reports the discussions he had with the organizer, Bruno Granier.

  • This conference will be the last French one. Next Congress in 2014 should be at the European level. NCS or universities are requested to propose an organisation of the conference or geological fieldtrips.
  • An initiative has been taken to update the old stratigraphical lexicon at world scale ; examples can be found on the Carnet Géologiques (web site: http://paleopolis.rediris.es/LEXICON )

Note that TS Creator (http://www.tscreator.com/index/index.php) is apparently a more promising initiative from ICS (J. Ogg).

b. Geological time scale

A new Geological Time scale will be published by Gradstein et al. in 2014. Main improvement will be the astrochronostratigraphical calibration. Table of content is already available.

c. ICS Meeting Prague (30 May - 3 June 2010)

The President was attending this meeting.

  • Definition of new GSSP's will continue
  • GSSP for several Devonian units should be re-evaluated, particularly for the base of Carboniferous. Biostratigraphic criteria appear unsatisfactory in some cases (conodont biometry and figuration).
  • Discussions about the use of geochronological and chronostratigraphical terms (Early/Lower, Late/Upper, Mid/middle)
  • LAD (last appearance data versus LOD (last occurrence data)
  • Use of upper/lower case for lower/upper. Upper case only if the subdivision is officially included in the stratigraphical chart.

5. Next meeting

Next meeting in December, with announcement in November

Luc Hance Noël Vandenberghe

Secretaris Président

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