ISCS accomplishments, achievements and products

 

 

1. Subdivision of the Cambrian

Formal boundaries of the base and top of the Cambrian Period have been defined by the Working Groups on the Precambrian-Cambrian and the Cambrian-Ordovician boundaries in 1992 and 1997, respectively. In 1998, the International Subcommission on Cambrian Stratigraphy (ISCS) started to tackle the next logical goals of the ISCS. These are to provide temporal subdivisions within the period.

A first phase of activities of the Cambrian Subdivision Working Group served a general reconnaissance during international field conferences of the Cambrian Subdivision Working Group in Morocco (1995), Spain (1996), eastern Canada (1997), Sweden (1998), the Great Basin (1999), Argentina (2000), and South China (2001). Starting in 1998, ISCS Chairman J. H. Shergold and ISCS Secretary G. Geyer reviewed widely recognizable, precisely correlatable biohorizons that may serve to define internal Cambrian stage- or series-level boundaries and possible chronostratigraphic units in accordance to the Cambrian Global Subdivision Project (CGSP). The first step at the end of 1999/beginning of 2000 was a largely informal query to members of the ISCS asking for general opinions about the possibility of subdividing the Cambrian. This led to the recognition of 16 biohorizons that were suggested as to have potential of global correlation. These biohorizons were chosen for a first estimation.

The next step was the installation of Working Groups on selected levels. The first of this Working Groups, the WG on a Glyptagnostus reticulatus level GSSP, finally worked out a proposal on a Global Standard Stratotype Section and Point for a newly established stage and series (lower) boundary. This GSSP, defined by the FAD of Glyptagnostus reticulatus in the section of Paibi, Hunan Province, China, defines the base of the new global Paibian Stage and Furongian Series, which now represents the Upper Cambrian. The majority decision by the International Subcommission on Cambrian Stratigraphy was ratified by the International Commission on Stratigraphy (ICS) in summer 2002.

 

2. Regional Correlation Charts

Regional correlation charts on the Cambrian System have been generated and published since 1983. The following issues are available from the IUGS Secretariat, Geological Survey of Norway, P.O. Box 3006, N-7001 Trondheim, Norway. See LIST.

 

3. Publications of the Cambrian Subdivision Working Group(s)

The organizers of the meetings of the Cambrian Stage Subdivision Working Group(s) generated special volumes as follows:

·  Geyer, G. and E. Landing (eds.) 1995. MOROCCO '95. The Lower-Middle Cambrian Standard of Western Gondwana. Introduction, Field Guide, Abstracts, and Proceedings of the First Conference of the Lower Cambrian Stage Subdivision Working Group and I.G.C.P. Project 366 Ecological Aspects of the Cambrian Radiation. Beringeria Special Issue 2. 268 p., many figs. and pls. Contact Dr. Ed Landing, NYS Geological Survey, The State Education Department, Albany, NY 12230, E-mail elanding@museum.nysed.gov, for price and ordering information.

Liñán, E., J. A. Gámez Vintaned and R. Gozalo (eds.) 1996. II Field Conference of the Cambrian Stage Subdivision Working Groups. Spain, 13-21 September 1996. Field Trip Guide and Abstracts. 129 p., many figs.

·  Landing, E. and S. R. Westrop (eds.) 1998. AVALON 1997 - The Cambrian Standard. Third International Field Trip of the Working Group on Cambrian Chronostratigraphy and I.U.G.S. Project 366. New York State Museum Bulletin 492. 96 p., 29 figs.

This volume includes Introduction; a comprehensive, illustrated field trip guide to the latest Precambrian-lowest Ordovician of eastern Newfoundland and southern New Brunswick by E. Landing and S. R. Westrop; a revision of the Cambrian stratigraphic nomenclature and sequence stratigraphy of the Cambrian of Avalonian North America with a comparison with Avalonian Britain by E. Landing and S. R. Westrop; and seven abstracts of oral presentations. Anticipated publication date March 1, 1998; contact Dr. Ed Landing, NYS Geological Survey, The State Education Department, Albany, NY 12230, E-mail <elanding@museum.nysed.gov>, for price and ordering information.

·        Ahlberg, P. 1998. Guide to excursions in Scania and Västergötland, Southern Sweden. IV Field Conference of the Cambrian Stage Subdivision Working Group, International Subcommission on Cambrian Stratigraphy, Sweden, 24-31 August 1998. Lund Publications in Geology, 141, 47 p.

·        Ed Landing (Albany, NY) organized a special section in the Canadian Journal of Earth Sciences, Volume 35 (1998), devoted to Cambrian subdivisions and correlation as announced by this programmatic title. This set of articles is a contribution to the activities of the Cambrian Subdivision Working Group and includes papers by J. J. Álvaro & E. Vennin; M. D. Brasier & S. S. Sukhov; G. Geyer; B. Hamdi, A. Yu. Zhuravlev & P. D. Kruse; E. Landing; E. Landing, S. A. Bowring, K. Davidek, S. R. Westrop, G. Geyer & W. Heldmaier; A. R. Palmer; S. M. Rowland, V. A. Luchinina, I. V. Korovnikov, D. P. Sipin, A. I. Tarletskov & A. V. Fedoseev. See below for the relevant articles.

·        The Spanish Cambrian workers of, or originating from the Zaragoza institute organized a special issue of the Revista Española de Paleontología dedicated to the late ISCS Voting Member Gonzalo Vidal (Gámez Vintaned, J. A., Palacios, T., Liñán, E., Gozalo, R. & Martínez Chacón, M. L., ed., 1998. XII Jornadas de Paleontología, II Field Conference of the Cambrian Stage Subdivision Working Groups. Revista Española de Paleontología, No. Extr. Homenaje al Prof. Gonzalo Vidal, 148 pp.). This set of articles includes contributions by W. T. Chang; O. Elicki; G. Geyer & M. Streng; R. Gozalo & E. Liñán, J. B. Jago & P. W. Haines; A. Montero, C. Diéguez & D. Garcia-Bellindo; T. Palacios; T. Palacios & M. Moczydlowska; A. R. Palmer; G. Vidal; and A. Yu. Zhuravlev. See below for the relevant articles.

·        Palmer, A. R., ed., 1999. Laurentia 99. V Field Conference of the Cambrian Stage Subdivision Working Group. International Subcommission on Cambrian Stratigraphy. Utah, Nevada, California, U.S.A., September 12-22, 1999. Institute for Cambrian Studies, Boulder, CO.

·        The Acta Palaeontologica Sinica appeared at the end of 1999 with a special issue (Volume 38, Supplement) on the Early to Middle Cambrian formations in the Guizhou province, particularly the Kaili Formation that yields the eminent "Kaili fauna". The articles mostly review new research results of the working group of Zhao Yuan-long (Guiyang).

·        Reports on the Cambrian subdivisions were presented on the Field Conference of the Cambrian Subdivision Working Group “Argentina 2000” with comprehensive notes on the visited localities and sections. The brochure with the abstracts for this meeting was published by the Instituto Superior de Correlación Geológica (INSUGEO) (G. F. Aceñolaza & S. Peralta, eds., 2000. Cambrian from the southern edge. Instituto Superior de Correlación Geológica, Miscelánea 6, 148 pp.).

·        A set of thematic reports on the Cambrian subdivisions was presented on the Field Conference of the Cambrian Subdivision Working Group “China 2001”. Sixteen articles are included in a special volume of Acta Palaeontologica Sinica (The Cambrian of South China. Zhu Maoyan, Heyo Van Iten, Peng Shanchi, and Li Guoxiang, eds. Acta Palaeontologica Sinica 40, Supplement, 240 pp., Science Press, Beijing, 2001). A further 42 articles and abstracts are published in “Cambrian System of South China. Peng Shanchi, L. E. Babcock, and Zhu Maoyan, eds. Palaeoworld 13, 310 pp., University of Science and Technology of China Press, Hefei, 2001. This volume also includes the excursion Guide Book.

·        An abstract volume for the meeting Early Palaeozoic Palaeogeographies and Biogeographies of Western Europe and North Africa (Université des Sciences et Technologies de Lille (USTL) in Villeneuve d’Ascq, September 24-26, 2001) was generated by the meeting organizers J. J. Álvaro and T. Servais (78 pp.). A guidebook for the post-meeting excursion (The Cambrian and Lower Ordovician of the southern Montagne Noire: a synthesis for the beginning of the new century. J. J. Álvaro and D. Vizcaïno, eds.) is published in the Annales de la Société Géologique du Nord, 2e série, vol. 8, fasc. 4, p. 183-242.

 

4. Recent articles

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A number of comprehensive articles of general interest dealing entirely or at least partly with Cambrian stratigraphy published since late in 1995 are shown on the LIST OF ARTICLES. A set of thematic reports on the Late Neoproterozoic-Cambrian of southwest Mongolia represent achievements initiated during a ISCS/IGCP Project 303 field excursion in 1993 and provide a new view for the tectonic setting of Cambrian rocks. Similar activities concentrate on the Neoproterozoic-Cambrian transition of the northeast Siberian Platform and its chemo- and isotopic stratigraphy as well as its basin dynamics. They were published cummulatively in Geological Magazine.