ESTONIAN ACADEMY
PUBLISHERS
eesti teaduste
akadeemia kirjastus
PUBLISHED
SINCE 1952
 
Earth Science cover
Estonian Journal of Earth Sciences
ISSN 1736-7557 (Electronic)
ISSN 1736-4728 (Print)
Impact Factor (2022): 1.1
Hirnantian (latest Ordovician) bio- and chemostratigraphy of the Stirnas-18 core, western Latvia; pp. 1–24
PDF | doi: 10.3176/earth.2010.1.01

Authors
Linda Hints, Olle Hints, Dimitri Kaljo, Tarmo Kiipli, Peep Männik, Jaak Nõlvak, Helje Pärnaste
Abstract
Integrated study of the uppermost Ordovician Porkuni Stage in the Stirnas-18 core, western Latvia, has revealed one of the most complete Hirnantian successions in the eastern Baltic region. The interval is characterized by two shallowing upwards depositional sequences that correspond to the Kuldiga and Saldus formations. The whole-rock carbon stable isotope curve indicates a long rising segment of the Hirnantian carbon isotope excursion, with the highest peak in the upper part of the Kuldiga Formation. The bioclast carbon and oxygen curves fit well with the whole-rock carbon data. Micro- and macrofossil data enabled seven combined associations to be distinguished within the Hirnantian strata. The early Porkuni fauna of the Spinachitina taugourdeaui Biozone, with pre-Hirnantian affinities, is succeeded by an interval with a HindellaCliftonia brachiopod association, a specific polychaete fauna, the chitinozoan Conochitina scabra, and the conodont Noixodontus girardeauensis. The middle part of the Kuldiga Formation is characterized by a low-diversity Dalmanella testudinaria brachiopod association, high diversity of scolecodonts, and the occurrence of the chitinozoan Lagenochitina prussica. From the middle part of the Kuldiga Formation the youngest occurrence yet known of the conodont Amorphognathus ordovicicus is reported. Also typical of the Kuldiga Formation is the occurrence of the trilobite Mucronaspis mucronata. The uppermost Hirnantian Saldus Formation contains no shelly fauna, but yields redeposited conodonts and at least partly indigenous chitinozoans and scolecodonts. Palaeontological criteria and stable isotope data enable correlation of the Stirnas section with other Hirnantian successions in the Baltic region and elsewhere.
References

Achab, A., Asselin, E., Desrochers, A., Riva, J. & Farley, C. Chitinozoan biostratigraphy of a new Upper Ordovician stratigraphic framework for Anticosti Island, Canada. Geological Society of America, Bulletin [in press].

Ainsaar, L., Meidla, T. & Tinn, O. 2004. Middle and Upper Ordovician stable isotope stratigraphy across the facies belts in the East Baltic. In WOGOGOB-2004 Conference Materials (Hints, O. & Ainsaar, L., eds), pp. 11–12. Tartu University Press, Tartu.

Ainsaar, L., Kaljo, D., Martma, T., Meidla, T., Männik, P., Nõlvak, J. & Tinn, O. 2010. Middle and Upper Ordovician carbon isotope chemostratigraphy in Balto-scandia: a correlation standard and clues to environ-mental history. Palaeogeography, Palaeoclimatology, Palaeoecology,
doi:10.1016/j.palaeo.2010.01.003

Angelin, N. P. 1854. Palaeontologia Scandinavica I. Crustacea formationis transitionis, Fasc. 2, pp. 21–92, Sansom and Wallin, Lund.

Bahtin, V. V., Erinchek, P. T. & Karpitsky, V. Ya. 1969. The geological prerequisites for using methods of oil indraft intensification in carbonate jointy containers of the Upper Ordovician of western Latvia. In Voprosy regional¢ noj geologii Pribaltiki i Belorussii [Problems of regional geology of the East Baltic and Belarus] (Volkolakov, F. K. et al., eds), pp. 161–170. Riga [in Russian, with English summary].

Bergman, C. F. 1995. Symmetroprion spatiosus (Hinde), a jawed polychaete showing preference for reef environ­ments in the Silurian of Gotland. GFF, 117, 143–150.
doi:10.1080/11035899509546210

Bergström, J. 1968. Upper Ordovician brachiopod from Västergötland, Sweden. Geologica et Palaeontologica, 2, 1–35.

Bergström, S. M., Saltzman, M. M. & Schmitz, B. 2006. First record of the Hirnantian (Upper Ordovician) δ13C excursion in the North American Midcontinent and its regional implications. Geological Magazine, 143, 657–678.
doi:10.1017/S0016756806002469

Bergström, S. M., Young, S., Schmitz, B. & Saltzman, M. M. 2007. Upper Ordovician (Katian) δ13C chemo-strati­graphy: a Trans-Atlantic comparison. Acta Palaeontologica Sinica, 46 (Suppl.), 37–39.

Brangulis, A. P., Gailite, L. K., Zabels, A. J., Springis, T. K., Ulst, R. Z., Fridrihsone, A. I. & Yakovleva, V. I. 1989. Stratotipicheskie i opornye razrezy venda, kembriya i ordovika Latvii [Stratotype sections of the Vendian, Cambrian and Ordovician]. Zinatne, Riga, 155 pp. [in Russian].

Brenchley, P. J. & Cocks, L. R. M. 1982. Ecological associations in a regressive sequence: the Latest Ordovician of the Oslo-Asker District, Norway. Palaeontology, 25, 783–815.

Brenchley, P. J., Marshall, J. D., Carden, G. A. F., Robertson, D. B. R., Long, D. G. F., Meidla, T., Hints, L. & Anderson, T. F. 1994. Bathymetric and isotopic evidence for a short-lived Late Ordovician glaciation in a green­house period. Geology, 22, 295–298.
doi:10.1130/0091-7613(1994)022<0295:BAIEFA>2.3.CO;2

Brenchley, P. J., Marshall, J. D., Hints, L. & Nõlvak, J. 1997. New isotopic data solving an old biostratigraphic problem: the age of the upper Ordovician brachiopod Holorhynchus giganteus. Journal of the Geological Society, London, 154, 335–342.
doi:10.1144/gsjgs.154.2.0335

Brenchley, P. J., Carden, G. A., Hints, L., Kaljo, D., Marshall, J. D., Martma, T., Meidla, T. & Nõlvak, J. 2003. High-resolution stable isotope stratigraphy of Upper Ordovician sequences: constraints on the timing of bioevents and environmental changes associated with mass extinction and glaciation. GSA Bulletin, 115, 89–104.
doi:10.1130/0016-7606(2003)115<0089:HRSISO>2.0.CO;2

Carden, G. A. F. 1995. Stable Isotopic Changes Across the Ordovician–Silurian Boundary. PhD thesis. The University of Liverpool, 284 pp.

Chen, X., Rong, J. Y., Mitchell, C. E., Harper, D. A. T., Fan, J. X., Zhan, R. B., Zhang, Y. D., Li, R. Y. & Wang, Y. 2000. Late Ordovician to earliest Silurian graptolite and brachiopod biozonation from the Yangtze region, South China, with a global correlation. Geological Magazine, 137, 623–650.
doi:10.1017/S0016756800004702

Chen, X., Rong, J. Y., Fan, J. X., Zhan, R. B., Mitchell, C. E., Harper, D. A. T., Melchin, M. J., Peng, P., Finney, S. C. & Wang, X. F. 2006. The global boundary stratotype section and point (GSSP) for the base of the Hirnantian Stage (the uppermost of the Ordovician System). Episodes, 29, 183–196.

Delabroye, A. & Vecoli, M. 2010. The end-Ordovician glaciation and the Hirnantian Stage: a global review and questions about Late Ordovician event stratigraphy. Earth-Science Reviews, 98, 269–282.
doi:10.1016/j.earscirev.2009.10.010

Fan, J. X., Pen, P. G. & Melchin, M. J. 2009. Carbon isotopes and event stratigraphy near the Ordovician–Silurian boundary, Yichang, South China. Palaeogeography, Palaeoclimatology, Palaeoecology, 276, 160–169.
doi:10.1016/j.palaeo.2009.03.007

Finney, S. C., Berry, W. B. N., Cooper, J. D., Ripperdan, R. L., Sweet, W. C., Jacobson, S. R., Soufiane, A., Achab, A. & Noble, P. J. 1999. Late Ordovician mass extinction: a new perspective from stratigraphic sections in central Nevada. Geology, 27, 215–218.
doi:10.1130/0091-7613(1999)027<0215:LOMEAN>2.3.CO;2

Harper, D. A. T. & Rong, J. Y. 2008. Completeness of the Hirnantian brachiopod record: spatial heterogeneity through the end Ordovician Extinction event. Lethaia, 41, 19–197.
doi:10.1111/j.1502-3931.2008.00098.x

Harris, T. M., Sheehan, P. M., Ainsaar, L., Hints, L., Männik, P., Nõlvak, J. & Rubel, M. 2004. Upper Ordovician sequences of western Estonia. Palaeogeography, Palaeoclimatology, Palaeoecology, 210, 135–148.
doi:10.1016/j.palaeo.2004.02.045

Harris, M., Sheehan, P., Ainsaar, L., Hints, L., Männik, P., Nõlvak, J. & Rubel, M. 2005. The lower Silurian of Estonia: facies, sequences and basin filling. In The Sixth Baltic Stratigraphical Conference, Abstracts (Koren, T., Evdokimova, I. & Tolmacheva, T., eds), pp. 30–33. St. Petersburg.

Heath, R. J., Brenchley, P. J. & Marshall, J. D. 1998. Early Silurian carbon and oxygen stable-isotope stratigraphy of Estonia: implications for climate change. In Silurian Cycles. Linkages of Dynamic Stratigraphy with Atmo­spheric, Oceanic and Tectonic Changes (Landing, E. & Johnson, M. E., eds), New York State Museum, Bulletin, 491, 313–327.

Hints, L., Oraspõld, A. & Nõlvak, J. 2005. The Pirgu Regional Stage (Upper Ordovician) in the East Baltic: litho­stratigraphy, biozonation and correlation. Proceedings of the Estonian Academy of Sciences, Geology, 54, 225–259.

Hints, O. 2001. Distribution of scolecodonts. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 3, 12–14.

Hints, O. & Eriksson, M. E. 2007. Diversification and biogeography of scolecodont-bearing polychaetes in the Ordovician. Palaeogeography, Palaeoclimatology, Palaeo­ecology, 245, 95–114.
doi:10.1016/j.palaeo.2006.02.029

Hints, O., Killing, M., Männik, P. & Nestor, V. 2006. Frequency patterns of chitinozoans, scolecodonts, and conodonts in the upper Llandovery and lower Wenlock of the Paatsalu core, western Estonia. Proceedings of the Estonian Academy of Sciences, Geology, 55, 128–155.

Hints, O., Delabroye, A., Nõlvak, J., Servais, T., Uutela, A. & Wallin, Å. 2009. Biodiversity patterns of Ordovician acritarchs in Baltica: comparison with other palyno­morphs and sea-level changes. Palaeogeography, Palaeo­climatology, Palaeoecology,
doi:10.1016/j.palaeo.2009.11.003

Kaljo, D. & Hints, L. 1996. Late Ordovician–Early Silurian succession of palaeoecosystems in Estonia. Paleontological Journal, 30, 693–700.

Kaljo, D., Nõlvak, J. & Uutela, A. 1996. More about Ordovician microfossil diversity patterns in the Rapla section, northern Estonia. Proceedings of the Estonian Academy of Sciences, Geology, 45, 131–148.

Kaljo, D., Kiipli, T. & Martma, T. 1997. Carbon isotope event markers through the Wenlock–Pridoli sequence at Ohesaare (Estonia) and Priekule (Latvia). Palaeo­geography, Palaeoclimatology, Palaeoecology, 132, 211–223.
doi:10.1016/S0031-0182(97)00065-5

Kaljo, D., Hints, L., Martma, T., Nõlvak, J. & Oraspõld, A. 2001. Carbon isotope stratigraphy in the latest Ordovician of Estonia. Chemical Geology, 175, 49–59.
doi:10.1016/S0009-2541(00)00363-6

Kaljo, D., Hints, L., Martma, T., Nõlvak, J. & Oraspõld, A. 2004. Late Ordovician carbon isotope trend in Estonia, its significance in stratigraphy and environmental analysis. Palaeogeography, Palaeoclimatology, Palaeoecology, 210, 165–185.
doi:10.1016/j.palaeo.2004.02.044

Kaljo, D., Martma, T. & Saadre, T. 2007. Post-Hunnebergian Ordovician carbon isotope trend in Baltoscandia, its environmental implications and some similarities with that of Nevada. Palaeogeography, Palaeoclimatology, Palaeoecology, 245, 138–155.
doi:10.1016/j.palaeo.2006.02.020

Kaljo, D., Hints, L., Männik, P. & Nõlvak, J. 2008. The succession of Hirnantian events based on data from Baltica: brachiopods, chitinozoans, conodonts, and carbon isotopes. Estonian Journal of Earth Sciences, 57, 197–218.
doi:10.3176/earth.2008.4.01

Kielan, Z. 1960. Upper Ordovician trilobites from Poland, and some related forms from Bohemia and Scandinavia. Palae­ontologia Polonica, 11, 1–198.

Kiipli, E., Kiipli, T. & Kallaste, T. 2000. Early diagenetic chalcopyrite occurrences in Telychian marine red beds of West Estonia and West Latvia. Proceedings of the Estonian Academy of Sciences, Geology, 49, 294–307.

Kiipli, E., Kiipli, T. & Kallaste, T. 2009. Reconstruction of currents in the Mid-Ordovician–Early Silurian central Baltic Basin using geochemical and mineralogical indicators. Geology, 37, 271–274.
doi:10.1130/G25075A.1

Kiipli, T., Batchelor, R. A., Bernal, J. P., Cowing, C., Hagel-Brunnstrom, M., Ingham, M. N., Johnson, D., Kivisilla, J., Knaack, C., Kump, P., Lozano, R., Michiels, D., Orlova, K., Pirrus, E., Rousseau, R. M., Ruzicka, J., Sandstrom, H. & Willis, J. P. 2000. Seven sedimentary rock reference samples from Estonia. Oil Shale, 17, 215–223.

Koren¢, T. N. & Sobolevskaya, R. F. 2008. The regional stratotype section and point for the base of the Hirnantian Stage (the uppermost Ordovician) at Mirny Creek, Omulev Mountains, Northeast Russia. Estonian Journal of Earth Sciences, 57, 1–10.

Kursh, M. (ed.). 1977. Litologiya i poleznye iskopaemye paleozojskikh otlozhenij Pribaltiki [Lithology and mineral resources of the Palaeozoic deposits of the East Baltic]. Zinatne, Riga, 212 pp. [in Russian].

Long, D. G. F. 1993. Oxygen and carbon isotopes and event stratigraphy near the Ordovician–Silurian boundary, Anticosti Island Quebec. Palaeogeography, Palaeo­climatology, Palaeoecology, 104, 49–59.
doi:10.1016/0031-0182(93)90119-4

Männik, P. 2001. Distribution of conodonts. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 3, 10–12.

Männik, P. 2003. Distribution of conodonts. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 17–23.

Männil, R. 1966. Evolution of the Baltic Basin During the Ordovician. Valgus, Tallinn, 200 pp. [in Russian, with English summary].

Männil, R., Põlma, L. & Hints, L. 1968. Stratigraphy of the Viru and Harju series (Ordovician) of the Central East Baltic area. In Stratigraphy of the Baltic Lower Paleozoic and Its Correlation with Other Areas (Grigelis, A., ed.), pp. 81–110. Mintis, Vilnius [in Russian, with English summary].

Melchin, M. J. 2008. Restudy of some Ordovician–Silurian boundary graptolites from Anticosti Island, Canada, and their biostratigraphic significance. Lethaia, 41, 155–162.
doi:10.1111/j.1502-3931.2007.00045.x

Melchin, M. J. & Holmden, C. 2006. Carbon isotope chemo­stratigraphy in Arctic Canada: sea-level forcing of carbon platform weathering and implications for Hirnantian global correlation. Palaeogeography, Palaeoclimatology, Palaeoecology, 234, 186–200.
doi:10.1016/j.palaeo.2005.10.009

Modliński, Z., Nõlvak, J. & Szymanski, B. 2002. Chitinozoan biozonation of the Ordovician succession in the borehole Ketrzyn IG-1 (NE Poland). Przeglad Geologiczny, 50, 1149–1158.

Nõlvak, J. 1999. Ordovician chitinozoan biozonation of Baltoscandia. Acta Universitatis Carolinae Geologica, 43, 287–290.

Nõlvak, J. 2001. Distribution of chitinozoans. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 3, 8–10.

Nõlvak, J. 2003. Distribution of Ordovician chitinozoans. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 23–25, Appendixes 22, 23.

Nõlvak, J. & Grahn, Y. 1993. Ordovician chitinozoan zones from Baltoscandia. Palaeobotany and Palynology, 79, 245–269.
doi:10.1016/0034-6667(93)90025-P

Nõlvak, J., Hints, O. & Männik, P. 2006. Ordovician timescale in Estonia: recent developments. Proceedings of the Estonian Academy of Sciences, Geology, 55, 95–108.

Nõlvak, J., Hints, O., Männik, P. & Pärnaste, H. 2007. Ordovician time scale in Estonia. Acta Palaeontologica Sinica, 46 (Suppl.), 351–356.

Nõlvak, J., Meidla, T. & Hints, L. 1989. The Taučionys Formation (Holorhynchus beds) in the Iljinskoje Boring (Pskov district). Proceedings of the Academy of Sciences of the Estonian SSR, Geology, 38, 88–93.

Oraspõld, A. 1982. On the lithology of the Porkuni Stage in Central Latvia. Acta et Commentationes Universitatis Tartuensis, 527, 75–99 [in Russian, with English summary].

Oraspõld, A. 1986. The noncarbonate terrigenous component of the Saldus Formation in the northern part of East Baltic. Acta et Commentationes Universitatis Tartuensis, 759, 56–67 [in Russian, with English summary].

Owen, A. W. 1981a. The trilobite Mucronaspis in the upper­most Ordovician of the Oslo Region, Norway. Norsk Geologisk Tidsskrift, 61, 271–279.

Owen, A. W. 1981b. The Ashgill trilobites of the Oslo Region, Norway. Palaeontographica A, 175, 1–88.

Paris, F., Bourahrouh, A. & Hérissé, A. L. 2000. The effects of the final stages of the Late Ordovician glaciation on marine palynomorphs (chitinozoans, acritarchs, leiospheres) in well N1-2 (NE Algerian Sahara). Review of Palaeo­botany and Palynology, 113, 87–104.
doi:10.1016/S0034-6667(00)00054-3

Pärnaste, H., Popp, A. & Owens, R. M. 2009. Distribution of the order Proetida (Trilobita) in Baltoscandian Ordovician strata. Estonian Journal of Earth Sciences, 58, 10–23.
doi:10.3176/earth.2009.1.02

Paškevičius, J. 2000. Brachiopod communities of the Lithuanian facies zone in the Baltic Ordovician Basin. Geologija (Vilnius), 32, 14–35 [in Lithuanian, with English summary].

Põldvere, A. 2003. General geological setting and strati­graphy. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 6–12.

Rong, J. Y. & Harper, D. A. T. 1988. A global synthesis of the latest Ordovician Hirnantian brachiopod faunas. Transactions of the Royal Society of Edinburgh: Earth Sciences, 79, 383–402.

Rong, J. Y., Chen, X. & Harper, D. A. T. 2002. The latest Ordovician Hirnantia Fauna (Brachiopoda) in time and space. Lethaia, 35, 231–249.
doi:10.1080/00241160260288820

Rong, J. Y., Zhan, R. B. & Jin, J. 2004. The Late Ordovician and Early Silurian pentameride brachiopod Holorhynchus Kiaer, 1902 from North China. Journal of Palaeontology, 78, 287–299.
doi:10.1666/0022-3360(2004)078<0287:TLOAES>2.0.CO;2

Rubel, M., Hints, O., Männik, P., Meidla, T., Nestor, V., Sarv, L. & Sibul, I. 2007. Lower Silurian biostratigraphy of the Viirelaid core, western Estonia. Estonian Journal of Earth Sciences, 56, 193–204.
doi:10.3176/earth.2007.01

Schmitz, G. & Bergström, S. M. 2007. Chemostratigraphy in Swedish Upper Ordovician: regional significance of the Hirnantian δ13C excursion (HICE) in the Boda Limestone of the Siljan region. GFF, 129, 133–140.
doi:10.1080/11035890701292133

Sutcliffe, O. E., Harper, D. A. T., Salem, A. A., Whittington, R. J. & Craig, J. 2001. The development of an atypical Hirnantia-brachiopod Fauna and the onset of glaciation in the Ordovician of Gondwana. Transactions of the Royal Society of Edinburgh: Earth Sciences, 92, 1–14.
doi:10.1017/S0263593300000018

Suzuki, Y., Shiino, Y. & Bergström, J. 2009. Stratigraphy, carbonate facies and trilobite associations in the Hirnantian part of the Boda Limestone, Sweden. GFF, 131, 299–310.
doi:10.1080/11035890903452670

Temple, J. T. 1952. A revision of the trilobite Dalmanitina mucronata (Brongniart) and related species. Lunds Universitets Årsskrift. N.F., 48(2), 1–33, Pls. 1–4.

Temple, J. T. 1957. Growth of the glabella of Dalmanitina olini. Geological Magazine, 94, 491–497.
doi:10.1017/S0016756800070187

Temple, J. T. 1965. Upper Ordovician brachiopods from Poland and Britain. Acta Palaeontologica Polonica, 10, 379–450.

Turekian, K. K. & Wedepohl, K. H. 1961. Distribution of the elements in some major units of the Earth’s crust. Geological Society of America Bulletin, 72, 175–191.
doi:10.1130/0016-7606(1961)72[175:DOTEIS]2.0.CO;2

Ulst, R. Z. & Gailite, L. K. 1970. Border of the Ordovician and Silurian in Latvia and the lithostratigraphical sub-division. In Paleontologiya i stratigrafiya Pribaltiki i Belorussii [Palaeontology and stratigraphy of the East Baltic and Belarus] (Grigelis, A. A., ed.), pp. 283–295. Mintis, Vilnius.

Ulst, R. Z., Gailite, L. K. & Yakovleva, V. I. 1982. Ordovik Latvii [Ordovician of Latvia]. Zinatne, Riga, 294 pp. [in Russian].

Ulst, R. Z., Gailite, L. K. & Springis, T. K. 1984. Litho­stratigraphic subdivision of the subsurface Ordovician rocks of the Jelgava Depression. In Stratigrafiya drevnepaleozojskikh otlozhenii Pribaltiki [Stratigraphy of Early Palaeozoic deposits of the East Baltic]. pp. 77–93. Tallinn [in Russian, with English summary].

Vandenbroucke, T. R. A., Hennissen, J., Zalasiewicz, J. A. & Verniers, J. 2008. New chitinozoans from the historical type area of the Hirnantian Stage and additional key sections in the Wye Valley, Wales, UK. Geological Journal, 43, 397414.
doi:10.1002/gj.1109

Vanmeirhaeghe, J. 2006. The Evolution of the Condioz – Brabant Basin from Middle Ordovician and Llandovery: Lithostratigraphical and Chitinozoan Biostratigraphical Approach. Dissertation, Department of Geology and Soil Sciences, Ghent University, 233 pp.

Vanmeirhaeghe, J., Yans, J., Preat, A., Grassineau, N. & Verniers, J. 2005. New evidence for the Hirnantian (Upper Ordovician) in Belgium? An integrated isotopical, biostratigraphic and sedimentologic approach. Carnets de Géologie / Notebooks on Geology – Memoir, 2, 63–68.

Volkolakov, F. K. & Springis, T. K. 1969. Lithological features of the Upper Ordovician oil-bearing deposits in western Latvia. In Voprosy regional¢ noj geologii Pribaltiki i Belorussii [Problems of regional geology of the East Baltic and Belarus], pp. 161–170. Riga [in Russian, with English summary].

Whittington, H. B. 1968. A monograph of the Ordovician trilobites of the Bala area. Merioneth. Palaeontographical Society (Monograph), Part 4, 93–138.

Wigforss-Lange, J. 1999. Carbon isotope 13C enrichment in Upper Silurian (Whitcliffian) marine calcareous rocks in Scania, Sweden. GFF, 121, 273–279.
doi:10.1080/11035899901214273

Zhan, R. B. & Jin, J. 2007. Ordovician–Early Silurian (Llandovery) Stratigraphy and Palaeontology of the Upper Yangtze Platform, South China. Science Press, Beijing, 169 pp.

Zhang, T. G., Shen, Y. N., Zhan, R. B., Shen, S. Z. & Chen, X. 2009. Large perturbations of the carbon and sulfur cycle associated with the Late Ordovician mass extinction in South China. Geology, 37, 299–302.
doi:10.1130/G25477A.1

Back to Issue