Future Devonian Meetings

4th ICOS - International Conodont Symposium

Valencia (Spain)

25-30 June 2017


5th IPC - International Palaeontological Congress

Paris (France)

9-13 July 2018

 
 

 

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SDS Minutes 2008

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Minutes of the SDS Business Meeting

 Kitab State Geological Reserve, Uzbekistan, 2nd September 2008

 

 

1. Introduction

5. Devonian Chronostratigraphic Definitions

6. Membership

7. SDS Publications

9. Future Meetings  

10. Any other Business

 

 

R. Thomas Becker, assisted by CM U. Jansen (protocol)

 

Apart from TM Hladil and the Chairman, none of the present members and guests attended the Business Meeting at Oslo. Consequently it was decided to go through the complete Agenda of the Oslo Meeting, but giving special emphasis (and time) to the Emsian discussion, the main reason for the Field Symposium. In order to allow everybody to follow the discussion in all details, CM obut offered a complete translation from English into Russian and reverse.

The following Minutes will not repeat all the information of the Oslo Minutes. It will only concentrate on additional data and on the Emsian discussion.

 

Attendance: The Chairman, TMs J. Hladil, N. Izokh, J.I. Valenzuela-Rios; CMs N. Bakharev, P. Carls, R. Feist, U. Jansen, A. Kim, H. Matyja, O. Obut, L. Slavik; guests S. Berkyova (Prague), P. Cejchan (Prague), C. Crônier (Lille), K. De Baets (Zürich), C. Dojen (Münster), I. Evdokinova (St. Petersburg), M. Erina (Tashkent), J. Fryda (Prague), F. Karimova (Tashkent), I.A. Kim (Tashkent), V.G. Khromych (Novosibirsk), L. Koptikova (Prague), O. Mesentseva (Novosibirsk), N. Meshchankina (Tashkent), E.D. Michailova (St. Petersburg), H.-G. Mittmeyer (Schlangenbad, Germany), S V. Nikolaeva (Moscow), U.D. Rakhmonov (Kitab), O. Rodina (Novosibirsk), F. Salimova (Tashkent), M. Schemm-Gregory (Frankfurt), G.D. Webster (Pullman, Washington).

 

Document: Carls, P., Slavik, L. & Valenzuela-Rios: Request and comments concerning the GSSP for the basal Emsian stage boundary, 9 pp., 1 Fig. [see SDS newsletter 23 (2009)].

 

1. Introduction

The Chairman opened the SDS Business Meeting and expressed his warmest thanks to the Uzbek hosts, notably to I.B. Turamuratov, in his function as meeting Chairman, to N.G. Mavlyanov, Chairman of the State Committee on Geology and Mineral Resources of Uzbekistan (SCGMR Ruz), and to the Devonian team of Uzbekistan, with A. Kim, U. Rakhmonov, N. Meshchankina, M. Erina, and others. The present SDS members are overwhelmed by the Uzbek hospitality, by the pleasant and comfortable set-up in the Kitab Reserve, by the perfect organisation, the wonderful sections, and the beauty of the nature. The outcrop quality and fossil content are amongst the best on a global scale for the Lower Devonian and this ensures that many Devonian workers will like to return to the area. The Chairman emphasized the importance of the long Tashkent-Novosibirsk cooperation, which enabled this meeting, which allowed the significant recent research progress, and which is of highest importance for the solution of the current problems of Emsian stratigraphy. Amongst many others, special thanks is given to the unfortunately absent CM Yolkin, to CM Bakharev, TM Izokh, and CM Obut. The sometimes tiring translation service of Olga was very crucial for the great success of the meeting and excursion. The oral presentations included  many high-quality contributions that covered all of the Devonian and many regions. There were almost 30 talks and 18 posters. It is especially important that a wealth of new data for the Devonian of Uzbekistan and of Russian regions have been made available to the international scientific community. The Kitab Meeting will be long remembered and will result in a lasting improvement of communication between Devonian specialists and in true friendship between workers that had not much previous contact. Independent from the outcome of the Emsian revisions, there is the unanimous feeling that the excursion and symposium of the last days has been a great success. All SDS members that did not attend will have to regret that they missed the event.

Stratigraphy as a geoscience discipline suffers in general from the lack of a first class journal with high international reputation and high impact factor. In this respect the Chairman draws attention to the re-juvenation of the “Newsletters on Stratigraphy”, which, since early 2008 (or starting with vol. 43), has the formal support of ICS and IUGS. The journal´s editorial board has been broadened and the format enlarged. SDS members are recommended to grab this improved publication opportunity.

 

 

5. Devonian Chronostratigraphic Definitions

 

5.1. Lochkovian

The Chairman stated that he recognized that some workers started to use subdivisions of the Lochkovian in publications. He asked whether there was a wish for future formal subdivision. TM Valenzuela-Rios, CM Carls and C. Dojen confirmed the use of three informal substages (lower, middle, upper). A formal substage recognition seems possible but requires additional work.

 

5.2. Pragian

In relation with the Emsian, a new Pragian discussion is inevitable. CM Slavik explained the difficulties of the basal Pragian definition since Eognathodus sulcatus, the traditional basal index taxon, is very rare in the Barrandian and has been found 20 cm below the GSSP. Currently, the entry of “Icriodus” steinachensis is used as approximation. M. Erina, consequently, asked for a revision of the Pragian base. CM Carls and Slavik re-iterated the problem (see Document) that the current Emsian GSSP is placing more than half of the type region Pragian (or Praha Limestone) into the lower Emsian. In other words, the Pragian Stage has lost much oft its distinction and duration.

 

5.3. Emsian

There was a prolonged discussion concerning the base of the Emsian and its substage subdivision. The long and free exchange of arguments, not repeating here the Document statements, can be summarized as follows:

CM Carls: The alleged 15.4 Ma duration of the Emsian in the absolute Kaufmann scale needs to be critically evaluated by biostratigraphers. The current, strongly shortened Pragian, between the Pragian and Kitab GSSPs, as well as the interval between the latter and the traditional (German) Emsian can be re-defined as new chronostratigraphic units (substages).

CM Bakharev: A subdivision of the Emsian into three substages, keeping the Kitab GSSP, should be considered. Endemism and strong facies control on distributions characterize many brachiopods; this questions the significance of the German Emsian brachiopod zonation in relation with the conodont stratigraphy. The entry of Po. kitabicus works fine in the Salair.

CM Jansen: The Siegenian-Emsian brachiopod succession of the Emsian type region has been long and well studied, especially the spiriferid phylogeny. It allows correlations with other European regions (Spain) and to some extent also with North Africa. It uses evolutionary changes, not facies-controlled local occurrences.

M. Erina: The entry of Po. kitabicus marks a very important step in early polygnathid evolution, which was also emphasized in her oral contribution. Therefore, the GSSP should stay where it is.

TM Valenzuela-Rios: The Emsian revision requires a very careful restudy of the Zinzilban conodonts, especially the entry of the Po. excavatus Group, which includes several forms. Po. kitabicus provides a very important and useful time marker, but not for the basal Emsian since it enters much too early.

Chairman: GSSPs can and are often placed outside the traditional areas of chronostratigraphic units (e.g., Givetian, Frasnian, Famennian) but they should be close to the unit base in their classical type-region. The meaning of a chronostratigraphic term should not change too much in a type region since this would create great confusion. Without purpose, this rule has been violated in the case of the Emsian. A future subdivision of the Emsian into two substages has already been voted on by SDS. A revised GSSP decision must take other fossil groups into consideration, too. Statements are needed in which region the kitabicus boundary has been successfully applied. As said before (SDS Newsletter 22), the appearance of true Icriodus or of the I. corniger Group is a very useful level in Europe and North Africa to recognize an Upper Emsian substage, also with the oldest anarcestids. Unfortunately, the entry of Icriodus s.str. has not yet been correlated into North America and Asia, mostly because of endemism in conodonts.

CM Carls: The kitabicus level probably can be recognized in Nevada.

TM Hladil: The gamma ray spectroscopy and magnetic susceptibility should be studied in the GSSP section, as it has been in the Barrandian. The Czech group has already started work in the Zinzilban Gorge and will complete the field work during an additional week after the meeting.

CM Kim: Studies of the Zinzilban nowakiids continue and the Now. (Dmitriella) praesulcata Group of the Barrandian needs to be re-investigated, too.

J. Fryda: Investigations of Emsian isotope stratigraphy has started in Czechia and will be expanded to the Kitab sections. P. Lukes is currently finishing an extensive revision of Barrandian nowakiids, including Now. cancellata, which is important for the Emsian substage subdivision. The Bulletin of Geosciences is available for fast publication of new Zinzilban results and correlation summaries.

CM Feist: New Zinzilban data need to be published quickly.

TM Izokh: The entry of Po. nothoperbonus seems to be a good level for the intra-Emsian substage boundary but both nothoperbonus and Po. inversus should be restudied carefully.

Chairman: SDS has decided to search for a level close to the Dalejan Event (e.g. Now. cancellata level) for the substage boundary. Po. nothoperbonus enters much earlier, in the middle of the Zlichovian and in the middle of Anetoceras faunas.

 

The present members voted formally on the following conclusions:

1.      A majority recommended to revise the base of the Emsian. A future GSSP level shall be searched for near the entry of Po. excavatus (its subspecies or morphotypes) in order to correlate more closely with the base of the brachiopod-defined classical Emsian of the German type-region and with the Zlichovian of the Barrandian.

2.      In accord with the decision at the Novosibirsk Business Meeting in 2005, any future new Emsian GSSP will be placed in the Zinzilban section, too.

3.      The current Emsian GSSP in the Zinzilban Gorge shall become the GSSP for the base of a formal Upper Pragian substage, possibly named as Zinzilbanian.

4.      Formal voting on these issue will await the outcome of the new re-sampling by various working groups.

5.      Results of the re-sampling shall be reported immediately to the Uzbek (CM Kim) and Novosibirsk SDS members and to the SDS Newsletter, preferably no later than in 2010.

6.      All results shall be published in a joint international publication, coordinated by the Uzbek-Novosibirsk Devonian team. This requires taxonomic agreements between involved specialists.

7.      Brachiopod and other specialists are asked to correlate their zonations better with the conodont and dacryoconarid successions, or to publish updated summaries of such correlations.

8.      The Emsian substage definition has to await new dacryoconarid and conodont data and the outcome of the basal Emsian revision.

 

5.6. D/C Boundary

Based on her excellent work on the new Uzbekistan sdection, M. Erina has been proposed as additional member of the new D/C Boundary Working Group. CM Feist commented on the problems of the La Serre GSSP and on the problems to find any other good section in future that is not equally affected by the Hangenberg Event.

 

6. Membership

Two new CMs were proposed and voted on unanimously:

Utkir J. Rakhmonov, Kitab State Geological Reserve, specialist of Devonian crinoids (especially of columnals), rahmonov06@mail.ru.

Jiri Fryda, Czech Geological Survey, specialist of gastropods and multiple stratigraphic disciplines.

The Chairman welcomed both in SDS and emphasized the importance that Uzbekistan is represented by an additional active worker.

 

7. SDS Publications

Contributions to Newsletter 24 are due at the end of 2008.

 

9. Future SDS Meetings

The Devonian Meeting 2009 in conjunction with the North American Paleontological Convention (NPAC), in June in Cincinnati, will have a focus on the relation between sea-level changes and evolution. The main goal is to improve and revise the Devonian eustatic curve, a topic that is of highest significance for the hydrocarbon exploration industry. It is hoped to arrange in future some industrial sponsorship but this requires improved industry contacts.

The Secretary has repeated his offer to lead a field trip to the Old Red Devonian, in conjunction with the 2002 IPC in London.

The Novosibirsk Group, notably CM Bakharev, kindly offered a field meeting in 2011, visiting the Kuznetsk and Kusbass regions of southern Siberia. The area offers fine Middle and Upper Devonian successions and the D/C boundary. Since SDS has not yet been to those regions, and in memory of the wonderful 2005 meeting, the proposal was well received and accepted.

The 2012 Business Meeting will have to be held in conjunction with the Brisbane IGC.

   

10. Any other Business

CM Kim and CM Rakhmonov held brief closing speeches, inviting all SDS Members and Devonian specialists to come back to the Kitab Reserve. The Chairman, once more, thanked everybody involved with the meeting organisation.