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Facies and sequence controls on the appearance of the Cambrian biota in southwestern Mongolia: implications for the Precambrian–Cambrian boundary

Published online by Cambridge University Press:  01 May 2009

J. F. Lindsay
Affiliation:
Australian Geological Survey Organisation, P. O. Box 378, Canberra, ACT, 2601, Australia
M. D. Brasier
Affiliation:
Department of Earth Sciences, Parks Road, Oxford University, Oxford OX1 3PR, UK
D. Dorjnamjaa
Affiliation:
Geological Institute, Peace Avenue, Ulaan Baatar, P. O. Box 863, People's Republic of Mongolia
R. Goldring
Affiliation:
PRIS, University of Reading, Whiteknights Park, Reading RG6 2AD, UK
P. D. Kruse
Affiliation:
Northern Territory Geological Survey, Darwin, NT, 0801, Australia
R. A. Wood
Affiliation:
Department of Earth Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EQ, UK

Abstract

Neoproterozoic–Cambrian rocks of the Zavkhan Basin (Govi-Altay, western Mongolia) comprise large-scale alternations of siliciclastic- and carbonate-dominated units (cf. ‘Grand Cycles’). Analysis of such depositional sequences near the base of the Cambrian confirms that the distribution of trace fossils, small shelly fossils and calcimicrobial structures was strongly controlled by ecology and taphonomy, corresponding to specific points in a sea-level cycle. Evolution of the Cambrian biota is thus viewed through aseries of narrow time windows, once only for each depositional cycle. Correlation of the Precambrian–Cambrian boundary level on the basis of the first appearance of the Phycodes pedum assemblage is also fraught with difficulty, since stratigraphic resolution may be limited to a single sea-level cycle(c. 1–5 Ma). It is suggested that, in many cases, basin analysis will need to be undertaken before this boundary can be drawn.

Type
Articles
Copyright
Copyright © Cambridge University Press 1996

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References

Bowring, S. A., Grotzinger, J. P., Isachsen, C. E., Knoll, A.H., Pelechaty, S. M. & Kolosov, P., 1993. Calibrating rates of Early Cambrian evolution. Science 261, 129–8.CrossRefGoogle ScholarPubMed
Brasier, M. D., 1979. The Cambrian radiation event. In The Origin of Major Vertebrate Groups, (ed. House, M. R.), pp.103–59. The Systematics Association, Special Volume 12, New York: Academic Press.Google Scholar
Brasier, M. D., 1982. Sea-level changes, facies changes and the late Precambrian–Cambrian evolutionary explosion. Precambrian Research 17, 105–23.CrossRefGoogle Scholar
Brasier, M. D., 1990. Phosphogenic events and skeletal preservation across the Precambrian—Cambrian boundary interval. In Phosphorite Research and Development (eds Notholt, A. G., and Jarvis, I.), pp.282303. Special Paper of the Geological Society, London no. 52.Google Scholar
Brasier, M. D., 1992 a. Background to the Cambrian explosion. Journal of the Geological Society, London 149, 585–7.CrossRefGoogle Scholar
Brasier, M. D., 1992 b. Paleoceanography and changes in the biological cycling of phosphorus across the Precambrian—Cambrian boundary. In Origin and early evolution of the Metazoa (eds Lipps, J. H., and Signor, P. W.), pp.483523. New York: Plenum.CrossRefGoogle Scholar
Brasier, M. D. & Hewitt, R. A., 1979. Environmental setting of fossiliferous rocks from the uppermost Proterozoic-LowerCambrian of central England. Palaeogeography, Palaeoclimatology, Palaeoecology 27, 35–7.CrossRefGoogle Scholar
Brasier, M. D., Anderson, M. M. & Corfield, R. M., 1992. Oxygen and carbon isotope stratigraphy of early Cambriancarbonates in southeastern Newfoundland and England. Geological Magazine 129, 265–79.CrossRefGoogle Scholar
Brasier, M. D., Cowie, J. W. & Taylor, M. E., 1994. Decision on the Precambrian—Cambrian stratotype. Episodes 17, 38.CrossRefGoogle Scholar
Brasier, M. D., Shields, G., Kuleshov, V. N. & Zhegallo, Le. A., 1996. Integrated chemo- and biostratigraphic calibration of early animal evolution: Neoproterozoic—early Cambrian of southwest Mongolia. Geological Magazine 133, 445–85.CrossRefGoogle Scholar
Crimes, T. P., 1992. Changes in the fossil biota across the Proterozoic—Phanerozoic boundary. Journal of the Geological Society, London 149, 637–46.CrossRefGoogle Scholar
Crimes, T. P. & Anderson, M. M., 1985. Trace fossils from late Precambrian—early Cambrian strata of southeastern Newfoundland (Canada): temporal and environmental implications. Journal of Paleontology 59, 310–43.Google Scholar
Crimes, T. P. & Jiang, Zhiwen. 1986. Trace fossils from the Precambrian—Cambrian boundary candidate at Meischuncun, Jinning, Yunnan, China. Geological Magazine 123, 641–9.CrossRefGoogle Scholar
Dorjnamjaa, D., Bat-Ireedui, Y. A., Dashdavaa, Z. & Solemaa, D., 1993. Guidebook for excursion Precambrian—Cambriangeology Khasagt-Khavrhan Ridge, Gobi-Altay Province, Mongolia. Geological Institute of the Mongolian Academy of Science, 36 pp.Google Scholar
Fedonkin, M. A., 1985. Paleoichnology of the Vendian Metazoa. In The Vendian System: Historic and Palaeontologic basis.Volume 1 (eds Sokolov, B. S., and Ivanovsky, A. B.), pp. 112–16. Moscow: Izdatelstvo “Nauka” (in Russian).Google Scholar
Fedonkin, M. A., 1988. Paleoichnology of the Precambrian—Cambrian transition in the Russian platform and Siberia. In Trace Fossils, Small Shelly Fossils an thePrecambrian—Cambrian Boundary (eds Landing, E., and Narbonne, G. M.), pp. 12. New York State Museum Bulletin vol. 463, University of New York.Google Scholar
Fritz, W. H. & Crimes, T. P., 1985. Lithology, trace fossils, and correlation of Precambrian—Cambrian boundary beds, Cassiar Mountains, north-central British Columbia. Geological Survey of Canada, Paper 83–13.Google Scholar
Gibsher, A. S., Bat-Ireedui, Y. A., Balakhonov, I. G. & Efremenko, D. E., 1991. The Bayan Gol reference section of the Vendian-Lower Cambrian in central Mongolia (sub-division and correlation). Late Precambrian and Early Paleozoic of Siberia. Siberian Platform and its framework (ed. Khomentovsky, V. V.), pp.107–20. Novosibirsk: Ob’edinennyy Institut Geologii, Geofiziki i Mineralogii, Sibirskoe Otdelenie, Akademiya Nauk SSSR, 151 pp.Google Scholar
Goldring, R. & Jensen, S., 1996. Trace fossils and biofabrics at the Precambrian—Cambrian boundary interval in western Mongolia. Geological Magazine 133, 403–15.CrossRefGoogle Scholar
Hambrey, M. J. & Harland, W. B., 1985. The Late Proterozoic glacial era. Palaeogeography, Palaeoclimatology, Palaeoecology 51, 255–72.CrossRefGoogle Scholar
Haq, B. U., Hardenbol, J. & Vail, P. R., 1987. The chronology of fluctuating sea level since the Triassic. Science 235, 1156–67.CrossRefGoogle ScholarPubMed
Haq, B. U., Hardenbol, J. & Vail, P. R., 1988. Mesozoic and Cenozoic chronostratigraphy and eustatic cycles. Society of Economic Paleontologists and Mineralogists, Special Publication 42,71108.Google Scholar
Khomentovsky, V. V. & Gibsher, A. S., 1996. The Neoproterozoic—lower Cambrian in northern Govi-Altay, western Mongolia: regional setting, lithostratigraphy and biostratigraphy. Geological Magazine 133, 371–90.CrossRefGoogle Scholar
Landing, E., 1992. Precambrian—Cambrian boundary GSSP, SE Newfoundland: biostratigraphy and geochronology. Bulletin de Liaison et Informations, IUGS Subcommissionon Geochronology 11, 68.Google Scholar
Landing, E., 1994. Precambrian—Cambrian boundary global stratotype ratified and a new perspective of Cambrian time. Geology 22, 179–82.2.3.CO;2>CrossRefGoogle Scholar
Lindsay, J. F, Brasier, M. D., Shields, G., Khomentovsky, V.V. & Bat-Ireedui, Y. A., 1996. Glacial facies associations in a Neoproterozoic back-arc setting, Zavkhan Basin, western Mongolia. Geological Magazine 133, 391402.CrossRefGoogle Scholar
Lipps, J. H. & Signor, P. W., 1992. Origin and early evolution of the Metazoa. New York: Plenum, 570 pp.CrossRefGoogle Scholar
Mount, J. F., 1984. Mixing of siliciclastic and carbonate sediments in shallow shelf environments. Geology 12, 432–5.2.0.CO;2>CrossRefGoogle Scholar
Mount, J. F. & Signor, P. W., 1992. Faunas and facies—fact and artefact: paleoenvironmental controls on the distribution of Early Cambrian faunas. In Origin and early evolution of the Metazoa (eds Lipps, J. H., and Signor, P. W.), pp.2751. New York: Plenum.CrossRefGoogle Scholar
Myrow, P. & Hiscott, R. N., 1993. Depositional history and sequence stratigraphy of the Precambrian—Cambrian boundary stratotype section, Chapel Island Formation, southeast Newfoundland. Palaeogeography, Palaeoclimatology, Palaeoecology 104, 1335.CrossRefGoogle Scholar
Narbonne, G. M. & Aitken, J. D., 1990. Ediacaran fossils from the Sekwi Brook Area, Mackenzie Mountains, northwestern Canada. Palaeontology 33, 945–80.Google Scholar
Narbonne, G. M., Myrow, P. M., Landing, E. & Anderson, M. M., 1987. A candidate stratotype for the Precambrian—Cambrian boundary, Fortune Head, Burin Peninsula, southeastern Newfoundland. Canadian Journalof Earth Sciences 24, 1277–93.CrossRefGoogle Scholar
Plumb, K. A., 1991. New Precambrian time scale. Episodes 14, 139–40.CrossRefGoogle Scholar
Seilacher, A. & Goldring, R., (submitted). Class Psammocorallia (Coelenterate Vendian—Ordovician): systematics and distribution. Lethaia.Google Scholar
Semikhatov, M. A., 1991. General problems of Proterozoic stratigraphy in the USSR. Soviet Scientific Reviews, section G, Geology Reviews 1(1). Harwood, Reading, 1192.Google Scholar
ŞengöR, A. M. C., Natal’in, B. A. & Burtman, V. S., 1993. Evolution of the Altaid tectonic collage and Palaeozoic crustal growth in Eurasia. Nature 364, 299307.CrossRefGoogle Scholar
Sokolov, B. S. & Fedonkin, M. A., 1984. The Vendian as the terminal system of the Precambrian. Episodes 7, 1219.CrossRefGoogle Scholar
Vail, P. R., Hardenbol, J. & Todd, R. G., 1984. Jurassic unconformities, chronostratigraphy, and sea-level changes from seismic stratigraphy and biostratigraphy. In Interregional unconformities and hydrocarbon accumulations (ed. Schlee, J. S.), pp.6381. American Association of Petroleum Geologists Memoir no. 36.Google Scholar
Vail, P. R., Mitchum, R. M. Jr & Thompson, S., 1977. Seismic stratigraphy and global changes of sea level, part 3: relative changes of sea level from coastal onlap. In Seismic stratigraphy—applications to hydrocarbon exploration (ed. Payton, C. E.), pp.6381. American Association of Petroleum Geologists Memoir no. 26.Google Scholar
Vail, P. R., Mitchum, R. M. Jr & Thompson, S., 1977 y. Seismic stratigraphy and global changes of sea level, part 4: global cycles of relative changes of sea level. In Seismic stratigraphy—applications to hydrocarbon exploration (ed. Payton, C. E.), pp.8397. American Association of PetroleumGeologists Memoir no. 26.Google Scholar
Walter, M. R., Elphinstone, R. & Heys, G. R., 1989. Proterozoic and Early Cambrian trace fossils from the Amadeus and Georgina Basins, central Australia. Alcheringa 13, 209–56.CrossRefGoogle Scholar
Young, F. G., 1972. Early Cambrian and older trace fossils from the southern Cordillera of Canada. Canadian Journal of Earth Sciences 9, 117.CrossRefGoogle Scholar