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Phytoplankton from the Lower Cambrian Læså formation on Bornholm, Denmark: biostratigraphy and palaeoenvironmental constraints

Published online by Cambridge University Press:  01 May 2009

Małgorzata Moczydłowska  and
Gonzalo Vidal
Małgorzata Moczydłowska
Affiliation:
Micropalaeontological Laboratory, Institute of Palaeontology, Box 558, S-751 22 Uppsala, Sweden
Gonzalo Vidal
Affiliation:
Micropalaeontological Laboratory, Institute of Palaeontology, Box 558, S-751 22 Uppsala, Sweden
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Abstract

Acritarchs from the Lower Cambrian Læsså formation on Bornholm, Denmark, are taxonomically diverse. Their state of preservation, including thermal, mechanical and chemical alteration, is discussed. Different states of thermal maturation of acritarchs in shales and phosphorites of the Broens Odde member could be explained in terms of possible irradiation from natural radioactive decay. The microfossils form two age-diagnostic assemblages that allow recognition of the Skiagia ornata–Fimbriaglomerella membranacea and Heliosphaeridium dissimilare–Skiagia ciliosa Assemblage Zones within the Broens Odde member of the Laeså formation. Acritarch-based biostratigraphy indicates that the Lower Cambrian Balka Formation and Læså formation correspond to the Schmidliellus mickwitzi Zone and Holmia kjerulfi Assemblage Zone recognized in Baltoscandia and the East European Platform. Acritarch distribution within three different depositional settings indicates that comparable spectra of morphotypes occurred in different depositional environments. This suggests the absence of facies control. During early Cambrian times palaeoenvironmental barriers in shallow, epicontinental shelf basins constituted a minor obstacle for widespread distribution of acritarch taxa. Formerly proposed early Palaeozoic acritarch provincialism appears insufficiently documented in the fossil record and no evidence could be extracted from the Cambrian record. Following a rapid radiation at the onset of the Phanerozoic, Cambrian phytoplankton populations underwent dispersion following oxygenic and nutrient-rich bodies of water within epicontinental and presumably basinal environments. Lower Cambrian acritarch taxa were largely cosmopolitan and little affected by lithofacies associations. A continuous flow of data is contributing to the emergence of acritarch-based biostratigraphy. Its apparent consistency suggests great usefulness for interregional and detailed event correlation.

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Geological Magazine , Volume 129 , Issue 1 , January 1992 , pp. 17 - 40
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Copyright © Cambridge University Press 1992

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References

Al-Ameri, T. K. 1983. Acid-resistant microfossils used in the determination of Palaeozoic palaeoenvironments in Libya. Palaeogeography, Palaeoclimatology, Palaeoecology 44, 103–16.CrossRefGoogle Scholar
Awramik, S. M., Schulte McMenamin, D., Yin, Chongyu, Zhao, Ziqiang, Ding, Qixiu & Zhang, Shusen. 1985. Prokaryotic and eukaryotic microfossils from a Proterozoic/Phanerozoic transition in China. Nature 315, 655–8.CrossRefGoogle Scholar
Baudet, D., Aitken, J. D. & Vanguestaine, M. 1989. Palynology of uppermost Proterozoic and lowermost Cambrian formations, central Mackenzie Mountains, northwestern Canada. Canadian Journal of Earth Sciences 26, 129–48.CrossRefGoogle Scholar
Bengtson, S. 1985. Redescription of the Lower Cambrian Halkieria obliqua Poulsen. Geologiska FÔreningens i Stockholm Förhandlingar 107, 101–6.CrossRefGoogle Scholar
Bergström, J. 1980. The Caledonian margin of the Fennoscandian shield during the Cambrian. In The Caledonides in the U.S.A. (ed. Wones, D. R.), pp. 9–13. Virginia Polytechnic Institute and State University, Department of Geological Sciences, Memoir no. 2.Google Scholar
Bergström, J. 1981. Lower Cambrian shelly faunas and biostratigraphy in Scandinavia. In Short Papers for the Second International Symposium on the Cambrian System 1981 (ed. Taylor, M. E.), pp. 22–5. U.S. Geological Survey Open-File Report 81–743.Google Scholar
Bergström, J. & Ahlberg, P. 1981. Upper Lower Cambrian biostratigraphy in Scania, Sweden. Geologiska Föreningens i Stockholm Förhandlingar 103, 193–214.CrossRefGoogle Scholar
Bergström, J. & Gee, D. G. 1985. The Cambrian in Scandinavia. In The Caledonide Orogen – Scandinavia and Related Areas Part 1 (eds Gee, D. G. and Sturt, B. A.), pp. 247–71. Chichester: John Wiley & Sons.Google Scholar
Brasier, M. D. 1989. Sections in England and their correlation. In The Precambrian-Cambrian Boundary (eds Cowie, J. W. and Brasier, M. D.), pp. 82–104. Oxford University Press.Google Scholar
Brasier, M. D. 1990. Nutrients in the early Cambrian Nature 347, 521–2.CrossRefGoogle Scholar
Berry, W. B. N., Wilde, P. & Quinby-Hunt, M. S. 1989. Paleozoic (Cambrian through Devonian) anoxitropic biotopes. Palaeogeography, Palaeoclimatology, Palaeoecology 74, 3–13.CrossRefGoogle Scholar
Butterfield, N.J., Knoll, A. H. & Swett, K. 1988. Exceptional preservation of fossils in an Upper Proterozoic shale. Nature 334, 424–7.CrossRefGoogle Scholar
Clausen, C. K. & Vilhjámsson, M. 1986. Substrate control of Lower Cambrian trace fossils from Bornholm, Denmark. Palaeogeography, Palaeoclimatology, Palaeoecology 56, 51–68.CrossRefGoogle Scholar
Colbath, G. K. 1980. Abundance fluctuations in Upper Ordovician organic-walled microplankton from Indiana. Micropalaeontology 26, 97–102.CrossRefGoogle Scholar
Colbath, G. K. 1990. Palaeobiogeography of Middle Palaeozoic organic-walled phytoplankton. In Palaeozoic Palaeogeography and Biogeography (eds McKerrow, W. S. and Scotese, C. R.), pp. 207–13. Geological Society Memoir no. 12.Google Scholar
Cook, P. J. & McElhinny, M. W. 1979. A reevaluation of the spatial and temporal distribution of sedimentary phosphate deposits in the light of plate tectonics. Economic Geology 74, 315–30.CrossRefGoogle Scholar
Cramer, F. H. 1968. Silurian palynologie microfossils and paleolatitudes. Neues Jahrbuch für Geologie und Paläontologie, Mh. 10, 591–7.Google Scholar
Cramer, F. H. 1970 a. Distribution of selected Silurian acritarchs. Revista Española Micropaleontologia, Numerò Extraordinario 1, 1–203.Google Scholar
Cramer, F. H. 1970 b. Middle Silurian continental movement estimated from phytoplankton-facies transgression. Earth and Planetary Science Letters 19, 87–93.CrossRefGoogle Scholar
Cramer, F. H. & Díez, M. D. C. R. 1972. North American Silurian palynofacies and their spatial arrangement: acritarchs. Palaeontographica, Pt B 138, 107–80.Google Scholar
Cramer, F. H. & Di´ez, M. D. C. R. 1974. Early Paleozoic palynomorph provinces and paleoclimate. In Paleographie Provinces and Provinciality (ed. Ross, C. A.), pp. 177–88. Society of Economic Paleontologists and Mineralogists, Special Publication no. 21.CrossRefGoogle Scholar
Crimes, T. P. 1989. Trace fossils. In The Precambrian–Cambrian Boundary (eds Cowie, J. W. and Brasier, M. D.), pp. 166–85. Oxford: Clarendon Press.Google Scholar
Dahl, J., Hallberg, R. & Kaplan, I. R. 1988 a. The effects of radioactive decay of uranium on elemental and isotopic ratios of Alum Shale kerogen. Applied Geochemistry 3, 583–9.CrossRefGoogle Scholar
Dahl, J., Hallberg, R. & Kaplan, I. R. 1988 b. Effects of irradiation from uranium decay on extractable organic matter in the Alum Shales of Sweden. Organic Geochemistry 12, 559–71.CrossRefGoogle Scholar
Dam, G. & Clemmensen, L. 1988. Neksø Sandsten fra Nedre Kambrium. Varv 3, 84–8.Google Scholar
de Marino, A. 1980. Sandstones andphosphatized calcareous sediments of the Lower Cambrian Rispebjerg Sandstone, Bornholm, Denmark. Danmarks Geologiske Undersøgelse II, 113, 39 pp.CrossRefGoogle Scholar
Dorning, K. J. 1981. Silurian acritarch distribution in the Ludlovian shelf sea of South Wales and the Welsh Borderland. In Microfossils from Recent and Fossil Shelf Seas (eds Neale, J. W. and Brasier, M.), pp. 31–6. Chichester: Ellis Horwood Limited.Google Scholar
Downie, C. 1963. “Hystrichosphéres” (acritarchs) and spores of the Wenlock Shales (Silurian) of Wenlock, England. Palaeontology 6, 625–52.Google Scholar
Downie, C. 1973. Observations on the nature of the acritarchs. Palaeontology 16, 239–59.Google Scholar
Downie, C. 1982. Lower Cambrian acritarchs from Scotland, Norway, Greenland and Canada. Transactions of the Royal Society of Edinburgh, Earth Sciences 72, 257–82.CrossRefGoogle Scholar
Downie, C, Evitt, W. R. & Sarjeant, W. A. S. 1963. Dinoflagellates, hystrichospheres, and the classification of the acritarchs. Stanford University Publications in Geological Sciences 7, 1–16.Google Scholar
Eklund, C. 1990. Lower Cambrian acritarch stratigraphy of the Bårstad 2 core, Östergötland, Sweden. Geologiska Föreningens i Stockholm Förhandlingar 112, 19–44.CrossRefGoogle Scholar
Fridrichsone, A. I. 1971. [Acritarchs Baltisphaeridium and hystrichosphères (?) from the Cambrian deposits in Latvia.] In Palaeontology and Stratigraphy of Peribaltic and Byelorussia, Part 3, 5–22. Vilnius (in Russian).Google Scholar
Gnilovskaya, M. B. 1979. [Vendotaenids.] In Upper Precambrian and Cambrian Palaeontology of the East European Platform (eds Keller, B. M. and Rozanov, A. Yu.), 39–49. Moscow: Nauka (in Russian).Google Scholar
Gower, J. F. R., Denman, K. L. & Holyer, R. J. 1980. Phytoplankton patchiness indicates the fluctuation of mesoscale oceanic structure. Nature 288, 157–9.CrossRefGoogle Scholar
Gray, J. & Boucot, A.J. 1972. Palynological evidence bearing on the Ordovician–Silurian paraconformity in Ohio. Geological Society of America Bulletin 83, 1299–1314.CrossRefGoogle Scholar
Hagenfeldt, S. 1988. Acritarch assemblages of early and middle Cambrian age in the Baltic Depression and south-central Sweden. Geological Survey of Finland, Special Paper 6, 151–61.Google Scholar
Hagenfeldt, S. 1989 a. Lower Cambrian acritarchs from the Baltic Depression and south-central Sweden, taxonomy and biostratigraphy. Stockholm Contributions in Geology 41, 1–176.Google Scholar
Hagenfeldt, S. 1989 b. Middle Cambrian acritarchs from the Baltic Depression and south-central Sweden, taxonomy and biostratigraphy. Stockholm Contributions in Geology 41, 177–250.Google Scholar
Hamberg, L. 1990. Tidevands-og stormdominerede aflejringsmiljoer i den Nedre Kambriske Hardeberga Formation i Skåne og på Bornholm. Dansk Geologisk Forening, Årsskrift for 1987–89, 15–20.Google Scholar
Hamberg, L. 1991. Tidal and seasonal cycles in an early Cambrian shallow marine sandstone (Hardeberga Formation in Scania, Southern Sweden). Canadian Society of Petroleum Geologists, Memoir 16 (in press).Google Scholar
Hansen, K. 1936. Die Gesteine des Unterkambriums von Bornholm Nebst einigen Bemerkungen über die Tektonischen Verhältnisse von Bornholm. København: C. A. Reitzels Forlag. 194 pp.Google Scholar
Hayes, J. M., Kaplan, I. R. & Wedeking, W. 1983. Precambrian organic geochemistry, preserveration of the record. In Earth's Earliest Biosphere (ed. Schopf, J. W.), PP. 93–134. Princeton, New Jerseyu: Princeton University Press.Google Scholar
Hill, P. J. & Molyneux, S. G. 1988. Biostratigraphy, palynofacies and provincialism of Late Ordovician–Early Silurian acritarchs from northeast Libya. In Subsurface Palynostratigraphy of Northeast Libya (eds A., El-Arnauti, B., Owens and B., Thusu), pp. 27–43. Benghazi: Garyounis University.Google Scholar
Horowitz, A. 1987. Palynology and environment of deposition of uranium in Beaufort-West, South Africa. Palynology 11, 236.Google Scholar
Jacobson, S. R. 1979. Acritarchs as paleoenvironmental indicators in Middle and Upper Ordovician rocks from Kentucky, Ohio and New York. Journal of Paleontology 53, 1197–212.Google Scholar
Jankauskas, T. V. 1976. [New acritarch species from the Lower Cambrian in Peribaltic] In Stratigraphy and palaeontology of the Lower and Middle Cambrian in USSR (ed. Zhuravleva, I. T.), pp. 187–194. Novosibirsk: Nauka (in Russian.)Google Scholar
Jankauskas, T. V. In Volkova, N. A., Kirjanov, V. V., Piscun, L. V., Pashkyavichene, L. T. & Jankauskas, T. V. 1979. [Microflora.] In Upper Precambrian and Cambrian palaeontology of the East-European Platform, (eds Keller, B. M. and Rozanov, A. Yu.), pp. 4–38. Nauka, Moscow, (in Russian).Google Scholar
Jankauskas, T. V. (ed.) 1989. [Precambrian microfossils of the USSR]. Moscow: Nauka, 190 pp. (in Russian).Google Scholar
Kalvacheva, R., Sassi, F. P. & Zanferrari, A. 1986. Acritarch evidence for the Cambrian age of phyllites in the Agordo area (South-Alpine basement of Eastern Alps, Italy). Review of Paleobotany and Palynology 48, 311–26.CrossRefGoogle Scholar
Kirjanov, V. V. 1974. [New acritarchs from the Cambrian deposits of Volhynia.] Paleontologicheskij Zhurnal 2, 117–130.Google Scholar
Kirjanov, V. V. 1979. In Volkova, N. A., Kirjanov, V. V., Piscun, L. V., Pashkyavichene, L. T. & Jankauskas, T. V. 1979. [Microflora.] In Upper Precambrian and Cambrian palaeontology of the East-European Platform (ed. Keller, B. M. and Rozanov, A. Yu.), pp. 4–38. Moscow: Nauka. (in Russian).Google Scholar
Kirjanov, V. V. & Volkova, N. A. 1979. In Volkova, N. A., Kirjanov, V. V., Piscun, L. V., Pashkyavichene, L. T. & Jankauskas, T. V. 1979. [Microflora]. In Upper Precambrian and Cambrian palaeontology of the East-European Platform, (ed Keller, B. M. and Rozanov, A. Yu.), pp. 4–38. Moscow: Nauka. (in Russian).Google Scholar
Knoll, A. H. 1984. Microbiotas of the late Precambrian Hunnberg Formation, Nordaustlandet, Svalbard. Journal of Paleontology 58, 131–62.Google Scholar
Knoll, A. H. 1985. Exceptional preservation of photo-synthetic organisms in silicified carbonates and silicified peats. Philosophical Transactions of the Royal Society of London B 311, 111–22.Google Scholar
Knoll, A. H. & Butterfield, N. J. 1989. New window on Proterozoic life. Nature 337, 602–3.CrossRefGoogle ScholarPubMed
Knoll, A. H. & Calder, S. 1983. Microbiotas of the late Precambrian Rysso Formation, Nordaustlandet, Svalbard. Palaeontology 26, 467–96.Google Scholar
Knoll, A. H. & Ohta, Y. 1988. Microfossils in metasediments from Prins Karls Forland, western Svalbard. Polar Research 6, 59–67.CrossRefGoogle ScholarPubMed
Knoll, A. H. & Swett, K. 1985. Micropalaeontology of the late Proterozoic Veteranen Group, Spitsbergen. Palaeontology 28, 451–73.Google Scholar
Knoll, A. H. & Swett, K. 1987. Micropalaeontology across the Precambrian–Cambrian boundary in Spitsbergen. Journal of Paleontology 61, 898–926.CrossRefGoogle Scholar
Lindström, M. & Staude, H. 1971. Beitrag zur Stratigraphie der unterkambrischen Sandsteine des südlichsten Skandinaviens. Geologica et Palaeontologica 5, 1–7.Google Scholar
Mansuy, C. & Vidal, G. 1983. Late Proterozoic Brioverian microfossils from France, taxonomic affinity and implications of plankton productivity. Nature 302, 606–7.CrossRefGoogle Scholar
Martinsson, A. 1974. The Cambrian of Norden. In Lower Palaeozoic rocks of the World. Vol. 2 Cambrian of the British Isles, Norden, and Spitsbergen (ed. Holland, C. H.), pp. 185–283. London: Wiley-Interscience.Google Scholar
McClure, H. A. 1988. Chitinozoan and acritarch assemblages, stratigraphy and biogeography of the early Palaeozoic of Northwest Arabia. Review of Paleobotany and Palynology 56, 41–60.CrossRefGoogle Scholar
Moczydlowska, M. 1988. Thermal alteration of the organic matter around the Precambrian-Cambrian transition in the Lublin Slope of the East European Platform in Poland. Geologiska Föreningens i Stockholm Förhandlingar 110, 351–61.CrossRefGoogle Scholar
Moczydlowska, M. 1991. Acritarch biostratigraphy of the Lower Cambrian and the Precambrian-Cambrian boundary in southeastern Poland. Fossils and Strata 29, 1–127.CrossRefGoogle Scholar
Moczydlowska, M. & Vidal, G. 1986. Lower Cambrian acritarch zonation in southern Scandinavia and southeastern Poland. Geologiska Föreningens i Stockholm Förhandlingar 108, 201–23.CrossRefGoogle Scholar
Moczydlowska, M. & Vidal, G. 1988. Early Cambrian acritarchs from Scandinavia and Poland. Palynology 12, 1–10.CrossRefGoogle Scholar
Nautiyal, A. C. 1977. The paleogeographic distribution of Devonian acritarchs and biofacies belts. Journal of the Geological Society of India 18, 53–64.Google Scholar
Ogurtsova, R. N. 1985. [The plant microfossils of the Vendian-Lower Cambrian section in Maly Karatau]. Academy of Sciences of the Kirgiz SSR, Publishing House Ilim, Frunze, 135 pp. (in Russian).Google Scholar
Palacios Medrano, T. 1989. Microfosiles de pared organica del Proterozoico superior (Región Central de la Peninsula Ibérica). Memorias del Museo Paleontologico de la Universidad de Zaragoza no. 3, 91 pp.Google Scholar
Pedersen, G. K. 1989. The sedimentology of Lower Palaeozoic black shales from the shallow wells Skelbro 1 and Billegrav 1, Bornholm, Denmark. Bulletin of the Geological Society of Denmark 37, 151–73.CrossRefGoogle Scholar
Piper, J. D. A. 1985. Continental movements and breakup in Late Precambrian-Cambrian times: prelude to Caledonian orogenesis. In The Caledonide Orogen-Scandinavia and Related Areas Part 1 (eds Gee, D. G. and Sturt, B. A.), pp. 19–34. Chichester: John Wiley & Sons.Google Scholar
Pollard, R. T. & Regier, L. 1990. Large variations in potential vorticity at small spatial scales in the upper ocean. Nature 348, 227–9.CrossRefGoogle Scholar
Poulsen, C. 1967. Fossils from the Lower Cambrian of Bornholm. Det Kongelige Danske Videnskabernes Selskab Matematisk-fysiske Meddelelser 36 (2), 48 pp.Google Scholar
Poulsen, V. 1966. Cambro-Silurian Stratigraphy of Bornholm. Meddelelser fra Dansk Geologisk Forening bd. 16, hefte 2, 117–37.Google Scholar
Poulsen, V. 1969. Eokambrium og Palaeozoikum. Varv. Geologi på Bornholm, Ekskursionsförer Nr. 1, 23–41.Google Scholar
Poulsen, V. 1978. The Precambrian-Cambrian boundary in parts of Scandinavia and Greenland. Geological Magazine 115, 131–6.CrossRefGoogle Scholar
Pyatiletov, V. G. & Rudavskaya, V. A. 1985. [Acritarchs of the Yudomian.] In Vendian System. 1. Palaeontology (eds. Sokolov, B. S. and Ivanovsky, A. B.), pp. 151–8. Moscow: Nauka (in Russian).Google Scholar
Richardson, J. B. 1984. [Mid-Palaeozoic palynology, facies and correlation]. In Reports 21th International Geological Congress 1, pp. 159–69. Moscow: Nauka (in Russian).Google Scholar
Richardson, J. B. & Rasul, S. M. 1990. Palynofacies in a Late Silurian regressive sequence in the Welsh Borderland and Wales. Journal of the Geological Society, London 147, 675–86.CrossRefGoogle Scholar
Rovnina, L. V. 1981. Palynological method to determine the level of katagenesis of organic matter by using Jurassic deposits of Western Siberia. In Organic Maturation Studies and Fossil Fuel Exploration (ed. Brooks, J. G.), pp. 427–32. London: Academic Press.Google Scholar
Rudavskaya, V. A. & Vasileva, N. I. 1984. [The first finds of Lükati acritarchs in the Lower Cambrian Chukurovsk section of the Eastern Siberia]. Doklady Akademii Nauk SSSR 214, 1454–6.Google Scholar
Skjeseth, S. 1963. Contributions to the geology of the Mjøsa districts and the classical sparagmite area in southern Norway. Norges Geologiske Undersøkelse Bulletin no. 220, 126 pp.Google Scholar
Staplin, F. L. 1961. Reef-controlled distribution of Devonian microplankton in Alberta. Palaeontology 4, 392–424.Google Scholar
Staplin, F. L., Jansonius, J. & Pocock, S.A.J. 1965. Evaluation of some Acritarchous Hystrichosphere Genera. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 123, 167–201.Google Scholar
Surlyk, F. 1980. Denmark. In Geology of the European Countries, 1–50. Paris: Dunod. Published in cooperation with the Comité National Français de Géologie (C.N.F.G.) on the occasion of the 26th International Geological Congress.Google Scholar
Tappan, H. 1980. The Paleobiology of Plant Protists. San Francisco: W. H. Freeman and Company. 1028 pp.Google Scholar
Tappan, H. 1986. Phytoplankton: below the salt at the global table. Journal of Paleontology 60, 545–54.CrossRefGoogle Scholar
Thorpe, R. S., Beckinsale, R. D., Patchett, P. J., Piper, J. D. A., Davis, G. R. & Evans, J. A. 1984. Crustal growth and late Precambrian–early Palaeozoic plate tectonic evolution of England and Wales. Journal of the Geological Society, London 141, 521–36.CrossRefGoogle Scholar
Thorslund, P. 1960. The Cambro-Silurian. In Descriptions to Accompany the Map of the Pre-Quaternary Rocks of Sweden. Sveriges Geologiska Undersökning, Ba 16, 69–110.Google Scholar
Tynni, R. 1978. Lower Cambrian fossils and acritarchs in the sedimentary rocks of Söderfjärden, western Finland. Geological Survey of Finland, Bulletin 297, 39–81.Google Scholar
Vanderflit, E. K. 1971. In Umnova, N. I. & Vanderflit, E. K. 1971. [Acritarch assemblages from the Cambrian and Lower Ordovician deposits of the western and northwestern Russian platform]. In The Palynology Research in the Byelorussia and Other Regions of the USSR 68–73. Minsk: Publishing House Science and Engineering, (in Russian).Google Scholar
Vavrdová, M. 1974. Geographical differentiation of Ordovician acritarch assemblages in Europe. Review of Paleobotany and Palynology 18, 171–6.CrossRefGoogle Scholar
Vavrdová, M. 1982. Phytoplankton communities of Cambrian and Ordovician age of Central Bohemia. Véstnik Ústˇdniho Ústavu Geologického 57, 145–155.Google Scholar
Vidal, G. 1976. Late Precambrian microfossils from the Visingsö Beds in southern Sweden. Fossils and Strata 9, 57 pp.Google Scholar
Vidal, G. 1981 a. Micropalaeontology and Biostratigraphy of the Upper Proterozoic and Lower Cambrian Sequences in East Finnmark, Northern Norway. Norges Geologiske Undersøkelse Bulletin no. 362, 53 pp.Google Scholar
Vidal, G. 1981 b. Lower Cambrian acritarch stratigraphy in Scandinavia. Geologiska Föreningens i Stockholm Forhandlingar 103, 183–92.CrossRefGoogle Scholar
Vidal, G. 1981 c. Micropalaeontology and biostratigraphy of the Lower Cambrian sequence in Scandinavia. In Short Papers for the Second International Symposium on the Cambrian System 1981 (ed. Taylor, M. E.), pp. 232–5. U.S. Geological Survey Open-File Report 81–743.Google Scholar
Vidal, G. 1984. The Oldest Eukaryotic Cells. Scientific American 250, (2), 48–57.CrossRefGoogle ScholarPubMed
Vidal, G. 1985. Biostratigraphic correlation of the Upper Proterozoic and Lower Cambrian of the Fennoscandian Shield and the Caledonides of East Greenland and Svalbard. In The Caledonide Orogen - Scandinavia and Related Areas, Part 1 (eds Gee, D. G. and Sturt, B. A.), pp. 331–338. Chichester; John Wiley & Sons.Google Scholar
Vidal, G. 1990. Giant acanthomorph acritarchs from the Upper Proterozoic in Southern Norway. Palaeontology 33, 287–98.Google Scholar
Vidal, G. & Ford, T. D. 1985. Microbiotas from the late Proterozoic Chuar Group (Northern Arizona) and Uinta Mountain Group (Utah) and their chrono-stratrigraphic implications. Precambrian Research 28, 349–489.CrossRefGoogle Scholar
Vidal, G. & Knoll, A. H. 1982. Radiations and extinctions of plankton in the late Proterozoic and early Cambrian. Nature 297, 57–60.CrossRefGoogle Scholar
Vidal, G. & Knoll, A. H. 1983. Proterozoic plankton. Geological Society of America, Memoir 30, 265–77.CrossRefGoogle Scholar
Vidal, G. & Nystuen, J. P. 1990 a. Micropalaeontology, depositional environments and biostratigraphy of the Upper Proterozoic Hedmark Group, southern Norway. American Journal of Science 290-A, 170–211.Google Scholar
Vidal, G. & Nystuen, J. P. 1990 b. Lower Cambrian acritarchs and Proterozoic-Cambrian boundary in southern Norway. Norsk Geologisk Tidskrift 70, 191–222.Google Scholar
Vidal, G. & Peel, J. S. 1988. Acritarchs from the Buen Formation (Lower Cambrian), North Greenland, Gronlands Geologiske Undersøgelse, Rapport 137, p. 54.Google Scholar
Vidal, G. & Siedlecka, A. 1983. Planktonic, acid-resistant microfossils from the Upper Proterozoic strata of the Barents Sea region of Varanger Peninsula, East Finnmark, Northern Norway. Norges Geologiske Undersokelse, Bulletin 382, 45–79.Google Scholar
Volkova, N. A. 1968. [Acritarchs from the Precambrian and Cambrian deposits of Estonia.] In Problematics of Riphean and Cambrian layers of the Russian Platform, Urals and Kazakhstan (eds Volkova, N. A., Zhuravleva, Z. A., Zabrodin, V. E. and Klinger, B. Sh.), pp. 8–36. Moscow: Nauka (in Russian).Google Scholar
Volkova, N. A. 1969. [Acritarchs of the north-western Russian platform.] In Tommotian Stage and the Cambrian lower boundary problem (eds Rozanov, A. Yu. et al.), pp. 224–236. Moscow: Nauka (in Russian).Google Scholar
Volkova, N. A. 1985. [Acritarchs and other plant microfossils from the East European Platform.] In Vendian System. 1. Palaeontology (eds Sokolov, B. S. and Ivanovsky, A. B.), pp. 130–9. Moscow: Nauka (in Russian).Google Scholar
Volkova, N. A., Kirjanov, V. V., Piscun, L. V., Pashkyavichene, L. T. & Jankauskas, T. V. 1979. [Microflora.] In Upper Precambrian and Cambrian palaeontology of the East European Platform (eds Keller, B. M. and Rozanov, A. Yu.), pp. 4–38. Moscow: Nauka (in Russian).Google Scholar
Volkova, N. A., Kirjanov, V. V., Piscun, L. V., Paškevičiene, L. T. & Jankauskas, T. V. 1983. Plant Microfossils. In Upper Precambrian and Cambrian Palaeontology of the East European Platform (eds A., Urbanek and Rozanov, A. Yu.), pp. 7–46. Warszawa: Publishing House Wydawnictwa Geologiczne.Google Scholar
Wall, D. 1965. Microplankton pollen and spores from the Lower Jurassic in Britain. Micropalaeontology 11, 151–90.CrossRefGoogle Scholar
Waz`yńska, H. 1967. Wste¸pne badania mikroflorystyczne osadöw sinianu i kambru z obszaru Bialowiezy. Kwartalnik Geologiczny 11, 10–20. (English abstract).Google Scholar
Wood, G. D. & Stephenson, J. T. 1989. Cambrian palynomorphs from the warm-water provincial realm, Bonneterre and Davis Formations of Missouri and Arkansas (Reelfoot Rift area): biostratigraphy, paleo-ecology and thermal maturity. In Field Guide to the Upper Cambrian of Southeastern Missouri: Stratigraphy, Sedimentology and Economic Geology (eds Gregg, J. M., Palmer, J. R. and Kurtz, V. E.), pp. 84–102, Department of Geology and Geophysics, University of Missouri (Rolla), Geological Society of America Field Trip (Annual Meeting).Google Scholar
Yin, Leiming 1985. Microfossils of the Doushantuo Formation in the Yangtze Gorge district, western Hubei. Palaeontologica Cathayana 2, 229–49.Google Scholar
Yin, Leiming, 1987. New data of microfossils from Precambrian-Cambrian cherts in Ningqiang, southern Shaanxi. Acta Palaeontologica Sinica 26, 187–95.Google Scholar
Zang, W. L. & Walter, M. R. 1989. Latest Proterozoic plankton from the Amadeus Basin in central Australia. Nature 337, 642–5.CrossRefGoogle Scholar