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.............................................................................................................................. SDS Minutes 2004 .............................................................................................................................. Minutes of the SDS Business Meeting, FLORENCE, 23rd August 2004 1. Introduction and apologies for absence 2. Approval of the Minutes of the Business Meeting held in Rabat on 1st March 2004 3b. Subdivision of the Givetian 3c. Subdivision of the Frasnian 3d. Subdivision of the Famennian 3e. Publication of substage decisions 5. SDS Executive body and members for 2005-2008 6. Financial report, April to August 2004 The second SDS Business Meeting for 2004 took place in the frame of the 32nd International Geological Congress, Florence, in the afternoon of the 23rd August. Due to an overlap with a different meeting, SDS had to change the venue which resulted in a slightly later (17.15 p.m.) start than anticipated. In the morning of the same day, SDS organized a special symposium on “High-resolution stratigraphy (G22.03) for the subdivision of the Devonian stages”. Seven oral contributions were given, two additional ones, unfortunately, had to be cancelled on short notice. The session of talks was accompanied by a poster session with seven further presentations. A range of other Devonian talks was distributed among other symposia. The Agenda had been distributed via email/mail early in August 2004. Attendance As, unfortunately, typical for IGC´s, only a limited number of SDS members attended the meeting. These were the Chairman, the Secretary, TMs Hou Hongfei, H. Hüneke, J. Talent, S. Turner, CMs D. Brice, B. Ellwood, Ma Xueping, M. C. Perri, E. Schindler, H. P. Schönlaub, V. Tsyganko, and Guests Ali O. Amhemed, H. L. C. de Azevedo-Soares, S. Bergamaschi, N. Dow, S. Ellwood, P. Königshof, E. Pereira (total of nineteen). Five documents have been presented which were numbered as follows:
1. Introduction and apologies for absence ã The Chairman welcomed all participants and apologized for the sudden change of room arrangements. As all Subcommissions, SDS is committed to hold a Business Meeting and symposium in the frame of IGC´s and to take part in the symposia organized by ICS at the occasion. The main purpose was to make significant progress with the substage subdivisions in order to allow formal votes as soon as possible. Results of ballots and explanation of substage levels shall be made public by the Chairman and the Working Group chairmen in 2005 in a comprehensive contribution to Episodes. There is an offer by Geological Quarterly, a reviewed journal published by the Polish Geological Institute in Warsaw, to publish more substantial papers, ca. 20 pages long, on each substage later in 2005. These longer and multi-author explanations should illustrate regional reference sections and index fossils, edited by the substage chairmen. Apologies: TMs Crick, El Hassani, Feist, Kirchgasser, Klapper, Menner, Uyeno, Weddige, Yolkin, CMs Blieck, Burrow, Casier, Chen, Izokh, Jansen, Mawson, Mistiaen, Over, Racki, Sartenaer, Valenzuela-Rios, VerStraeten, Walliser, Yazdi. 2. Approval of the Minutes of the Business Meeting held in Rabat on 1st March 2004 ã The Minutes were distributed via email/standard mail. TM Turner added that her apologies were not recorded. Apart from this, the Minutes were approved unanimously. The Chairman gave a brief introduction to the present state of progress and urged to make first decisions until the end of the year or early in 2005. 3.a. Subdivision of the Emsian ã Two discussions took place: (1) Emsian conodont taxonomy and zonations and (2) the problem of finding an adequate level for the base of an upper Emsian substage near the base of the Dalejan, close to the inversus/laticostatus Zone, or close to the base of the cancellata Zone. (1) TM Talent explained the statement of CM Mawson in Newsletter 20 concerning the review of Bardashev et al. (2002), emphasizing the inadequate illustration of material and the problem of taxonomic oversplitting in polygnathids, especially with respect to the raising of intraspecific variants to species status. The lack of reference sections makes it impossible to accept the wide range of proposed new Emsian zones. In this respect, the attempt to subdivide the Emsian is seen to have experienced a major setback. Document 1 explains that the publication under discussion is more a taxonomic and phylogenetic review, rather than a biostratigraphic contribution. The Secretary emphasized that the proposed new zones are introduced as correlative alternatives based on supposed different polygnathid lineages, without introducing any stratigraphic refinement needed in the current SDS discussion. The taxonomic situation has become more complex but there are no new range data. Some of the proposed new genera, such as Linguipolygnathus, seem to be well justified, at least in the Middle Devonian. It is expected that the conodont specialists will continue their taxonomic debates for some time. (2) The Chairman reviewed the conodont succession of the La Grange Limestone (see Bultynck 1989, Cour. Forsch.-Inst. Senckenberg, 117: 173-203). He proposed to use the first entry of Po. gilberti to define the base of the Emsian. CM Schindler commented that the investigations of the classical Bohemian sections still has not been completed. Preliminary data suggest that Now. cancellata enters relative early in limestone below the main Daleje Shale. Palynomorph peaks have recently been identified. TM Talent noted that brachiopods allow a clear distinction of early and late Emsian faunas but this may be easier in the neritic than in the pelagic realm. This was confirmed by TM Hou. The Secretary drew attention to the unfortunate fact that Po. gilberti enters in the Grange Limestone still within the range of Anetoceras (Bultynck et al., SDS Document 1999) which was always regarded to be a typical Lower Emsian form. The Anteoceras Stufe or faunas should remain in the Lower Emsian and the boundary better be placed somewhat higher. He drew attention to the incoming of a completely new complex of icriodid species, such as the oldest true Icriodus, I. corniger ancestralis, I. fusiformis, and Caudi. culicellus, below the entry of oldest anarcestids, both in Spain and in the Dra Valley. These species are not known from beds with anetoceratids whilst the La Grange Limestone or the Zlichov Limestone have older forms, such as Lateri. beckmanni and Lateri. bilatericrescens. As a summary, there is still insufficient progress concerning a good marker taxon which allows easy recognition of the base of an Upper Emsian substage. Further and revised range data are urgently needed and should be submitted to the 2005 SDS meeting. 3.b. Subdivision of the Givetian ã The Chairman introduced the conodont chart forming Document 2, which includes conodont-ammonoid correlations for the Givetian and the known sealevel events. The Middle Givetian is proposed to start at the base of the rhenanus/varcus Zone, which roughly correlates with the entry of I. difficilis in the icriodid succession, and with a distinctive goniatite level in the Tafilalt. Just above, there is a significant regressive event, which allows to subdivide Depophase If of the Johnson et al. eustatic curve (If2 Regression). Similar regressive trends are also known from North America (Day et al. 1996). In New York, Po. rhenanus shows a delayed entry in the Tichenor Limestone and the Middle Givetian would start lower in the succession. The Secretary added that typical Middle Givetian goniatites are well known from the Ledyard and Wanakah Shale below the Tichenor Limestone. The Middle Givetian could start as low as with the Centerfield Limestone. Unfortunately, the formerly recorded Po. varcus Group of the correlative Hungry Hollow Formation and of the subsequent Widder Shale are not yet revised. The Upper Givetian is proposed (Aboussalam & Becker 2002) to start with the hermanni Zone. Correlation tables of this level from the monograph of Aboussalam (2003, Münst. Forsch. Geol. Paläont., 97, 332 pp.) were presented. The two proposals for the bases of the Middle and Upper Givetian will be put forwards for formal voting in the next Newsletter. 3.c. Subdivision of Frasnian ã A brief report by the Working Group leader, CM Over, was included in Newsletter 20. No objections concerning the two proposed levels for definition of Middle (base of punctata Zone = base of Mn 5 Zone) and Upper Frasnian (entry and transgressive spread of Pa. semichatovae, low in the MN 11 Zone or low in the Lower rhenana Zone) have been submitted. The Secretary presented evidence that both levels can be well recognized in the ammonoid succession. Voting will proceed with the next Newsletter. Unfortunately, there is still insufficient documentation of regional reference sections and of correlation with brachiopod zonations. 3.d. Subdivision of the Famennian ã The Secretary as Working Group leader gave a brief report. The two documents by Streel and Streel et al. were presented. There are two proposed alternative subdivisions in the decided system with four substages: base of Middle Famennian: base of Uppermost crepida or base of marginifera Zone base of Upper Famennian: base of Latest marginifera Zone or base of styriacus (Lower postera) Zone base of Uppermost Famennian: base of Upper expansa Zone (but variably defined by the entry of Bispathodus ultimus or by the entry of Pa. gonioclymeniae) Document 5 shows the correlation of entry levels of marker conodonts, ammonoids, and foraminiferes. Document 3 suggests that the entry of Po. gonioclymeniae and of Pseudopolygnathus trigonicus correlate well with the base of the German Wocklum Stufe re-defined by ammonoids (Muessenbiaergia sublaevis Zone). It was agreed that the base of the Upper expansa Zone (ranges of the three most important index conodonts left open for further discussion) should be proposed for formal vote since it lies near the base of the Belgian Strunian (probably only slightly above the base of the Etroeungt Formation). A preliminary vote will take place in case of the other two substage boundaries. This leaves the base of the Lower expansa Zone as too close to be suitable for the definition of the Upper Famennian. Members are urged to study in detail all relevant documents before giving their vote. 3.e. Publication of substage decisions ã (see 1.) ICS will hold several meetings through the IGC and all present members are asked to participate since they will be open to the public. Symposium S11.01 on “The Geological Time Scale – Recent Developments and Global Correlation” took place throughout the 22nd August. The main ICS Meeting was listed as Workshop DWO 03 on “Challenges and Directions in Global Stratigraphy” on 26th August. SDS, via its Chairman, will give a brief report on its activities and achievements. All Subcommissions are asked to submit documentation (location maps, stratigraphic columns, photos) of GSSPs, which will be placed in the PaleoStrat database. Eventually, illustrations of defining index species are also needed. Subcommissions were also asked to submit information on GSSP conservation for a presentation by ICS. 5. SDS Executive body and members for 2005-2008 ã ICS has approved the proposed new SDS executives for 2005-2008, Chairman R. T. Becker, Vice-Chairman A. El Hassani, and Secretary J.E.A.M Marshall. The revised ICS rules require that Voting Members (TMs) may serve a maximum uninterrupted period of twelve years. This resulted in the previously announced significant exchange of TMs for the next period until the IGC in 2008. Voting members may be selected by the Subcommission executives. All members have been asked to submit proposals and the new Titular Membership is composed of the few TMs who carry on and of all proposed candidates, who have been CMs before. The new membership is covering a wide array of countries and many different stratigraphic disciplines:
CM N. Izokh has been proposed to replace E. A. Yolkin from the forthcoming Novosibirsk Meeting on. M. Narkiewicz (Instytut Geologiczny, Rakowiecka 4, 00-975 Warszawa, Poland), who attended several SDS meetings on previous occasions, was proposed to become CM and was elected unanimously. He is specialized in conodont and sequence stratigraphy of Poland. 6. Financial Report, April to August 2004 ã
2005 Two meetings are supported by SDS: The 6th Baltic Stratigraphical Conference, St. Petersburg, Russia, August 23-25, co-organized by CM Ivanov (aoi@ai1205.spb.edu). This meeting includes a Post-conference field trip (no. C, 26-28th August) to the Devonian of Leningrad and Pskov districts (see SDS Newsletter 20, p. 9-12). International Conference on “Devonian Terrestrial and marine environments from continent to shelf”, 25th July – 9th August (including Altai-Salair field trip), co-organized by the Institute of Petroleum Geology, Russian Academy of Sciences, Siberian Branch, Novosibirsk (TM Yolkin, CM Izokh and collaborators), by IGCP 499, and by SDS. Our Subcommission will hold its Annual Business Meeting in Novosibirsk, on the 8th of August, and all members are invited to attend. 2006 SDS will meet in conjunction with ICOS 2006 in Leicester, UK, and our forthcoming Secretary John Marshall has agreed to lead a pre-conference fieldtrip to the Old Red Sandstone (terrestrial Devonian) of Scotland. Additionally, SDS members will convene at a special Devonian symposium together with IGCP 499 during the 2nd International Paleontological Congress in Beijing. In this case, our new TM Ma Xueping is in the organization committee. 2007 Our North American members (new TM Over and CM Morrow) have announced a meeting, including the Business Meeting, in Eureka, Nevada, followed by a seven to eight day fieldtrip (see SDS Newsletter 20, p. 5-6). 2008 SDS is committed to hold a symposium and meeting at the 33rd International Geological Congress. The Chairman drew attention to the new SDS publications, especially to the Field Trip Guidebook of the Rabat Meeting, which has been published in the Documents de l´Institut Scientifique (no. 19). For details see the homepage of the Institut Scientifique or contact TM El Hassani. VOTING FORM (for voting and corresponding members of 2006) Definition of the base of the Middle Givetian at the base of the rhenanus/varcus Zone yes no abstention TM CM Definition of the base of the Upper Givetian at the base of the hermanni Zone yes no abstention TM CM Definition of the base of the Middle Frasnian at the base of the punctata (MN 5) Zone yes no abstention TM CM Definition of the base of the Upper Frasnian by the first entry of Pa. semichatovae yes no abstention TM CM Definition of the base of the Uppermost Famennian by the base of the Upper expansa Zone yes no abstention TM CM PRELIMINARY VOTE Definition of the base of the Middle Famennian at the base of the Uppermost crepida Zone base of the marginifera Zone abstention alternative proposal: TM CM Definition of the base of the Upper Famennian at the base of the Uppermost marginifera Zone base of the styriacus (= Lower postera) Zone abstention alternative proposal TM CM This voting form (or a filled copy of it) should be send within six weeks to our secretary John Marshall. Alternatively, a vote by email is equally possible. |
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