PROJECTS

We are very happy to announce you that the new IGCP (International Geoscience Programme) project proposal “Ordovician Palaeogeography and Palaeoclimate”, that has been deposited at the IGCP office at Paris in October 2003, has been accepted by the IGCP Board last week. As announced earlier, over 180 scientists agreed to participate in the new project, that can be considered a successor project of IGCP 410 that mostof you know. The first scientifical meeting of our new project IGCP n° 503 "Ordovician Palaeogeography and Palaeoclimate" is now scheduled: the official Opening Meeting will be held at the University of Erlangen, Germany, September
1-3, 2004, directly following the International Geological Congress in Florence, Italy. Our opening congress will be followed by a field meeting to the Ordovician and Silurian of southern Sweden (Fagelsand GSSP, Öland, Gotland), September 4-12. With this message we invite you to take part in this congress and the field meeting. You can find all information on this meeting, but also on the new IGCP project 503 on the following website: http://www.pal.uni-erlangen.de/IGCP503/

Thomas Servais

Correlation of the Palaeozoic terranes in Bulgaria and NW Turkey: implications for the tectonic-palaeogeographic evolution of nw gondwana

A 2003-2004 project between TUBITAK and Bulgarian Academy of Science with leaders: Prof. Dr. M. Cemal Goncuoglu (Middle East Technical University, Department of Geological Engineering) and Prof. Dr. Slavcho Yanev (Bulgarian Academy of Sciences, Geological Institute).

Valeri Sachanski

SCIENTIFIC REPORTS

Is the name "Volkhovian" appropriate for the third global stage of the Ordovician System?

In several recent publications, Webby (1998) among them, the name "Volkhovian" has been used in place of the third global stage of the Ordovician System. Dronov with co-authors, studying many sections in Volkhov River area proposed to formalise the Volkhovian Stage as a global unit (Dronov et al. 2003). We certainly agree that Baltoscandia, including the Volkhov River area has many good sections and is representative of that particular interval of geological time. However, according to the International Stratigraphic Guide, the names of new stratigraphical units should be unique in order to prevent ambiguity. The term Volkhov(ian) unfortunately carries already stratigraphical meaning and is widely used in regional litho- and chronostratigraphical standards in NW Russia, Baltic countries, and Scandinavia (e.g., Männil and Meidla 1994). In latter two regions, it has mostly chronostratigraphical meaning whereas in NW Russia both Volkhov Regional Stage and Volkhov Formation are actively used, sometimes with different volume (e.g., Dronov et al. 2000).

Stratigraphical units having one and the same name but different definition and content may easily lead to confusion and errors, especially by people without stratigraphical background. Dronov et al. (2003) proposed re-classifying the regional Volkhov Stage. However, we see no way of doing that without negative impact on common understanding and usability of the regional stratigraphical standard. Since the base of the overlying Kunda Regional Stage does not coincide with the base of Darriwilian, the content of regional and global Volkhov(ian) will always remain different. Not to mention that also the lower boundary definitions and correlation criteria for global and regional Volkhov(ian) will likely turn out different. Hence we consider that "Volkhovian" is not appropriate name for the third global stage of the Ordovician System.

If it appears practical to find a suitable name from the Baltic region, we suggest the name "Lavan", after Lava River in the St. Petersburg region, some 40 km from the Volkhov River area (see e.g., Tolmacheva 2001, figs 4,8; Tolmacheva and Fedorov 2001). This term is also not entirely new to stratigraphy, but it has gained no regional acceptance and has never been used after the initial proposal by Iskjul and Kuznetsov (1962).

Dronov A.V., Koren T.N., Tolmacheva T.Ju., Holmer L. and Meidla T. 2003. “Volkhovian” as a name for the third global stage of the Ordovician System. In: Albanesi G.L., Beresi M.S. and Peralta S.H. (eds.). Ordovician from the Andes. INSUGEO, Serie Correlacion Geologica, 17: 59-65.

Dronov A.V., Meidla T., Ainsaar L. and Tinn O. 2000. The Billingen and Volkhov stages in the northern East Baltic: detailed stratigraphy and lithofacies zonation. Proc. Estonian Acad. Sci. Geol., 49: 3-16.

Iskjul, N.V. and Kuznetsov, S.S. 1962. Geology of the Lava River valley (Leningrad District). Academy of Sciences of USSR. Geological Museum. Studies. Vol. 11. Publishers of the Academy of Sciences of USSR. Moscow, Leningrad. 54 pp.

Männil R. and Meidla T. 1994. The Ordovician System of the East European Platform (Estonia, Latvia, Lithuania, Byelorussia, parts of Russia, the Ukraine and Moldova). In: B.D. Webby, R.J. Ross Jr. and Y.Y. Zeng (eds.), IUGS Publication No. 28, 1-52.

Tolmacheva T.Ju. 2001. Conodont biostratigraphy and diversity in the Lower-Middle Ordovician of Eastern Baltoscandia (St. Petersburg region, Russia) and Kazakhstan. Comprehensive Summary of Doctoral Dissertation. Department of Earth Sciences, Historical Geology and Palaeontology, Uppsala University. 40 pp.

Tolmacheva T. and Fedorov P. 2001. The Ordovician Billingen/Volkhov boundary interval (Arenig) at Lava River, nothwestern Russia. Norsk Geologisk Tidsskrift, 81: 161-168.

Webby B.D. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsl. Stratigr. 36,1-33.

Jaak Nõlvak, Olle Hints and Helje Pärnaste