Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-27T14:21:34.664Z Has data issue: false hasContentIssue false
  • English
  • Français

The Ordovician–Silurian boundary at Keisley, northern England

Published online by Cambridge University Press:  01 May 2009

A. D. Wright
A. D. Wright
Affiliation:
Department of Geology, The Queen's University of Belfast, Belfast, BT7 INN, Northern Ireland
Get access Rights & Permissions [Opens in a new window]

Abstract

The relationships of the Keisley Limestone, an isolated carbonate mudmound in the Cross Fell Inlier of northern England, have long been problematical with respect both to the other upper Ordovician as well as the Silurian strata of the inlier. Bedded limestones, separated by gaps from the Keisley mudmound below and from atavus Biozone graptolite shales above, yielded a prolific shelly fauna to Temple in 1968 which he regarded as being of lower Llandovery age. This age is controversial. To try to establish the precise ages of the rock units, the position of the Ordovician–Silurian boundary, and the detailed nature of the changes which took place at this boundary, a critical section was excavated. Bed by bed lithological and faunal collections reveal from beneath the known atavus outcrop (a) five bentonite bands, unexpected in the context of northern England, (b) graptolites of both acuminatus and persculptus Biozones above the bedded limestones and (c) a similar but distinct assemblage from siltstones associated with these limestones which contains Hirnantia elements. From the palaeontological evidence there is little doubt that the topmost part of the carbonate sequence is of Hirnantian age.

Type
Articles
Information
Geological Magazine , Volume 122 , Issue 3 , May 1985 , pp. 261 - 273
Copyright
Copyright © Cambridge University Press 1985

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

Brenchley, P. J. & Cocks, L. R. M. 1982. Ecological associations in a regressive sequence: the latest Ordovician of the Oslo–Asker District, Norway. Paleontology 25, 783–815.Google Scholar
Burgess, I. C. 1968. In Cross Fell Area Field Meeting (Shotton, F. W., Wadge, A. J. & Burgess, I. C.), p. 343. Proceedings of the Yorkshire Geological Society 36.Google Scholar
Burgess, I. C., Rickards, R. B. & Strachan, I. 1970. The Silurian strata of the Cross Fell area. Bulletin of the Geological Survey of Great Britain 32, 167–82.Google Scholar
Burgess, I. C. & Rushton, A. W. A. 1979. Skelgill Shales. In Geology of the country around Brough-under-Stain-more (Burgess, I. C. and Holliday, D. W.), p. 23. Memoir. Geological Survey of Great Britain. Sheet 31, 131 pp.Google Scholar
Dean, W. T. 1959. The Stratigraphy of the Caradoc Series in the Cross Fell Inlier. Proceedings of the Yorkshire Geological Society 32, 185–227.CrossRefGoogle Scholar
Dean, W. T. 1978. The trilobites of the Chair of Kildare Limestone (Upper Ordovician) of Eastern Ireland. Part 3. Palaeontographical Society Monograph 131, 99–129.CrossRefGoogle Scholar
Holland, C. H., Ross, R. J. & Cocks, L. R. M. 1984. Ordovician–Silurian boundary. Lethaia 17, 184.CrossRefGoogle Scholar
Hutt, J. E. 1974. The Llandovery graptolites of the English Lake District. Palaeontographical Society Monograph 128, 1–56.CrossRefGoogle Scholar
Ingham, J. K. 1966. The Ordovician rocks in the Cautley and Dent districts of Westmorland and Yorkshire. Proceedings of the Yorkshire Geological Society 35, 455–505.CrossRefGoogle Scholar
Ingham, J. K. 1980. Late Ordovician and Early Silurian Succession at Dob's Linn, near Moffat in Southern Scotland. I.U.G.S. Ordovician – Silurian Boundary Working Group Report 39, 11 pp.Google Scholar
Ingham, J. K. & Wright, A. D. 1972. The North of England. In A Correlation of Ordovician Rocks in the British Isles (ed. Williams, A., Strachan, I., Bassett, D. A., Dean, W. T., Ingham, J. K., Wright, A. D. & Whittington, H. B.), pp. 43–9, Geological Society of London Special Report no. 3.Google Scholar
Jaanusson, V. 1979. Carbonate mounds in the Ordovician of Sweden. Izvestiya Akademii Nauk Kazakhskoi S.S.R. Geologicheskaya Seriya 4, 92–9 (in Russian).Google Scholar
Marr, J. E. 1906. On the stratigraphical relations of the Dufton Shales and Keisley Limestone of the Cross Fell Inlier. Geological Magazine (decade 5) 3, 481–7.CrossRefGoogle Scholar
Marr, J. E. & Nicholson, H. A. 1888. The Stockdale Shales. Quarterly Journal of the Geological Society of London 44, 654–732.CrossRefGoogle Scholar
Orchard, M. J. 1980. Upper Ordovician conodonts from England and Wales. Geologica et Palaeontologica 14, 9–44.Google Scholar
Reed, F. R. C. 1896. The Fauna of the Keisley Limestone. Part I. Quarterly Journal of the Geological Society of London 52, 407–37.CrossRefGoogle Scholar
Reed, F. R. C. 1897. The Fauna of the Keisley Limestone. Part II. Conclusion. Quarterly Journal of the Geological Society of London 53, 67–106.CrossRefGoogle Scholar
Rickards, R. B. 1970. The Llandovery (Silurian) Graptolites of the Howgill Fells, Northern England. Palaeontographical Society Monograph 123, 1–108.Google Scholar
Rickards, R. B. 1978. Silurian. In The Geology of the Lake District (ed. Moseley, F.), pp. 130–45. Yorkshire Geological Society Occasional Publication no. 3.Google Scholar
Rickards, R. B. 1979. The Lake District and Northern England. In Field Meeting Great Britain March 30–April 11, 1979 (ed. Bassett, M. G., Cocks, L. R. M., Holland, C. H., Ingham, J. K., Lawson, J. D., Rickards, R. B. and Temple, J. T.), pp. 37–41. I.U.G.S. Ordovician–Silurian Boundary Working Group Guidebook.Google Scholar
Rong, Jia-Yu. 1979. The Hirnantia fauna of China with comments on the Ordovician–Silurian boundary. Acta Stratigraphica Sinica 3, 1–28.Google Scholar
Rong, Jia-Yu. 1984. Distribution of the Hirnantia fauna and its meaning. In Aspects of the Ordovician System (ed. Bruton, D. L.), pp. 101–12. Palaeontological contributions from the University of Oslo No. 245. Universitetsforlaget.Google Scholar
Ross, R. J. Jr, Naeser, C. W., Izett, G. A., Obradovich, J. D., Bassett, M. G., Hughes, C. P., Cocks, L. R. M., Dean, W. T., Ingham, J. K., Jenkins, C. J., Rickards, R. B., Sheldon, P. R., Toghill, P., Whittington, H. B. & Zalasiewicz, J. 1982. Fission-track dating of British Ordovician and Silurian stratotypes. Geological Magazine 119, 135–53.CrossRefGoogle Scholar
Temple, J. T. 1968. The Lower Llandovery (Silurian) brachiopods from Keisley, Westmorland. Palaeontographical society Monograph 122, 1–58.CrossRefGoogle Scholar
Temple, J. T. 1969. Lower Llandovery (Silurian) trilobites from Keisley, Westmorland. Bulletin of the British Museum (Natural History). Geology 18, 197–230.Google Scholar
Thorslund, P. 1936. Siljanomradets brännkalkstenar och kalkindustri. Sveriges Geologiska Undersökning Series C, no. 398, 1–64.Google Scholar
Thorslund, P. & Jaanusson, V. 1960. The Cambrian, Ordovician, and Silurian in Västergötland, Närke, Dalarna, and Jämtland, Central Sweden. Guide to excursions Nos. A23 and C18. International Geological Congress, XXI Session, Norden.Google Scholar
Toghill, P. 1968. The graptolite assemblages and zones of the Birkhill Shales (Lower Silurian) at Dobb's Linn. Palaeontology 11, 654–68.Google Scholar
Warburg, E. 1925. The trilobites of the Leptaena Limestone in Dalarne. Bulletin of the Geological Institution of the University of Upsala 17, 1–446.Google Scholar
Williams, A. & Wright, A. D. 1981. The Ordovician-Silurian Boundary in the Garth area of southwest Powys, Wales. Geological Journal 16, 1–39.CrossRefGoogle Scholar
Wright, A. D. 1968. A westward extension of the upper Ashgillian Hirnantia fauna. Lethaia 1, 352–7.CrossRefGoogle Scholar
Wright, A. D. 1982. A new species of Ptychopleurella (Brachiopoda) from the Upper Ordovician Boda Limestoneof Dalarna, Sweden. Journal of Palaeontology 56, 351–7.Google Scholar