Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-24T23:31:59.870Z Has data issue: false hasContentIssue false

Probable microbial origin of Ordovician (Arenig) phosphatic pebble coats (‘ Bolopora ’) from North Wales, U.K.

Published online by Cambridge University Press:  01 May 2009

R.-O. Niedermeyer
Affiliation:
Department of Geological Sciences, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn Strasse, 17a, Greifswald 2200, German Democratic Republic
R. Langbein
Affiliation:
Department of Geological Sciences, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn Strasse, 17a, Greifswald 2200, German Democratic Republic

Abstract

Results are presented of thin-section, SEM, X-ray and microprobe investigations on problematical phosphatic accretions (‘ Bolopora ’) from the St Tudwal's area of North Wales. The data supplement investigations made by H. J. Hofmann on the genesis of the accretions, and indicate a microbial (bacteriogenic) origin. The bacteriogenic pebble coats are of dahllite. Microbial relics suggest water–sediment interface-linked formation of the coatings under subtidal, and oxic to anoxic, environmental conditions during a sedimentary hiatus.

Type
Articles
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Atlas, E. & Pytkowicz, R. M. 1977. Solubility behaviour of apatites in Seawater. Limnology and Oceanography, 22, 290300.CrossRefGoogle Scholar
Banerjee, D. M. 1978. Chemical rhythmicity in the Precambrian laminated phosphatic stromatolites and its bearing on the origin of algal phosphorite. Indian Journal Earth Science, 5, 102110.Google Scholar
Baturin, G. N. 1982. Phosphorites on the sea floor. Origin, Composition and distribution. Developments in Sedimentology, 33, 343 pp.Google Scholar
Beckley, A. J. 1987. Basin development in North Wales during the Arenig. Geological Journal, 22, 1930.CrossRefGoogle Scholar
Bentor, Y. K. 1980. Phosphorites – the unsolved problems. In Marine phosphorites – geochemistry, occurrence, genesis. (ed. Bentor, Y. K.), pp. 318. Society of Economic Paleontologists and Mineralogists, Special Publication 29.CrossRefGoogle Scholar
Brown, G. 1961. Other Minerals. In The X-ray identification and crystal structures of clay minerals. Mineralogical Society, London, 467488.Google Scholar
Burnett, W. C. & Froelich, P. N. (Eds) 1988. The origin of marine phosphorite. The results of the R.V. “Robert D. Conrad Cruise 23–06” to the Peru Shelf. Marine Geology, Special Issue, 80, 181346.Google Scholar
Crimes, T. P. 1970. A facies analysis of the Arenig of Western Lleyn, North Wales. Proceedings of the Geologists Association, 81, 221239.CrossRefGoogle Scholar
Froelich, P. N., Arthur, M. A., Burnett, W. C., Deakin, M., Hensley, V., Jahnke, R., Kaul, L., Kim, K.-H., Roe, K., Soutar, A. & Vathakanon, C. 1988. Early diagenesis of organic matter in Peru continental margin sediments: phosphorite precipitation. In The origin of marine phosphorite. The results of the R.V. “Robert D. Conrad Cruise 23–06” to the Peru Shelf (ed. Burnett, W. C. & Froelich, P. N.), Marine Geology, Special Issue, 80, 309343.Google Scholar
Glenn, R. C. & Arthur, M. A. 1988. Petrology and major element geochemistry of Peru-Margin phosphorites and associated diagenetic minerals: authigenesis in modern organic-rich sediments. In The origin of marine phosphorite. The results of the R.V. “Robert D. Conrad Cruise 23–06“ to the Peru Shelf (ed. Burnett, W. C. & Froelich, P. N.), Marine Geology, Special Issue, 80, 2267.Google Scholar
Goldring, R. 1985. The formation of the trace fossil Cruziana. Geological Magazine, 122, 6572.Google Scholar
Hallberg, R. O. 1973. The microbiological C-N-S cycles in sediments and their effect on the ecology of the sediment-water interface. OIKOS Supplement, 15, 5162.Google Scholar
Hofmann, H. J. 1975. Bolopora not a bryozoan, but an Ordovician phosphatic, oncolitic accretion. Geological Magazine 112, 523–6.CrossRefGoogle Scholar
Jahnke, R. A., Emerson, S. R., Roe, K. K. & Burnett, W. C. 1983. The present day formation of apatite in Mexican Continental margin sediments. Geochimica Cosmochimica Acta, 47, 259266.CrossRefGoogle Scholar
Kennedy, W. J. & Garrison, R. E. 1975 a. Morphology and genesis of nodular chalks and hardgrounds in the Upper Cretaceous of Southern England. Sedimentology, 22, 311386.CrossRefGoogle Scholar
Kennedy, W. J. & Garrison, R. E. 1975 b. Morphology and genesis of nodular phosphates in the Cenomanian Glauconitic Marl of Southeast England. Lethaia, 8, 339360.CrossRefGoogle Scholar
Krajewski, K. P. 1983. Albian pelagic phosphate-rich macro-oncoids from the Tatra Mts. (Poland). In Coated Grains (ed. Peryt, T.), pp. 344357. Berlin/Heidelberg/New York: Springer.CrossRefGoogle Scholar
Lewis, H. P. 1926. Bolopora undosa gen. et sp. nov. Quarterly Journal of the Geological Society of London, 82, 411427.CrossRefGoogle Scholar
Lucas, J. & Prévôt, L. 1984. Synthèse de l'apatite par voie bactérienne à partir de matière organique phosphatée et de divers carbonates de calcium dans de eaux douce et marine naturelles. Chemical Geology, 42, 101118.CrossRefGoogle Scholar
Lucas, J. & Prévôt, L. 1985. The synthesis of apatite by bacterial activity: mechanism. Sciences Geologiques Memoire, 77, 8392.Google Scholar
McArthur, G. M. 1983. Offshore Peruvian phosphorite: A re-appraisal of its age and genesis. Chemical Geology, 38, 93105.CrossRefGoogle Scholar
Nicholas, T. C. 1915. The geology of the St. Tudwal's Peninsula (Caernarvonshire). Quarterly Journal of the Geological Society of London, 71, 83139.CrossRefGoogle Scholar
Niedermeyer, R.-O. & Schomburg, J. 1984. Phosphoritic nodules from the Late Cretaceous of Mielnik (Poland) and some aspects of the genesis of phosphorites. Chemie der Erde, 43, 139148.Google Scholar
Pedley, H. M. & Bennett, S. M. 1985. Phosphorites, hardgrounds and syndepositional solution subsidence: A palaeoenvironmental model from the Miocene of the Maltese Islands. Sedimentary Geology, 45, 134.CrossRefGoogle Scholar
Riggs, S. R. 1979. Phosphorite sedimentation in Florida – A model phosphogenic system. Economic Geology, 74, 285314.CrossRefGoogle Scholar
Soudry, D. & Champetier, Y. 1983. Microbial processes in the Negev phosphorites (Southern Israel). Sedimentology, 30, 411423.CrossRefGoogle Scholar
Soudry, D. 1987. Ultra-fine structures and genesis of the Campanian high-grade phosphorites (Southern Israel). Sedimentology, 34, 641660.CrossRefGoogle Scholar