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Fission-track dating of British Ordovician and Silurian stratotypes

Published online by Cambridge University Press:  01 May 2009

R. J. Ross Jr ,
C. W. Naeser ,
G. A. Izett ,
J. D. Obradovich ,
M. G. Bassett ,
C. P. Hughes ,
L. R. M. Cocks ,
W. T. Dean ,
J. K. Ingham  and
C. J. Jenkins
...Show all authors
R. J. Ross Jr
Affiliation:
Department of Geology, Colorado School of Mines, Golden, Colorado 80401, U.S.A.
C. W. Naeser
Affiliation:
U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225, U.S.A.
G. A. Izett
Affiliation:
U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225, U.S.A.
J. D. Obradovich
Affiliation:
U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225, U.S.A.
M. G. Bassett
Affiliation:
Department of Geology, National Museum of Wales, Cardiff CF1 3NP, U.K.
C. P. Hughes
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, U.K.
L. R. M. Cocks
Affiliation:
Department of Palaeontology, British Museum (Natural History), Cromwell Road, London SW7 5BD, U.K.
W. T. Dean
Affiliation:
Department of Geology, University College, Cardiff CF1 1XL, U.K.
J. K. Ingham
Affiliation:
Department of Geology, Hunterian Museum, University of Glasgow, Glasgow G12 8QQ, U.K.
C. J. Jenkins
Affiliation:
Department of Geology, Australian National Museum, P.O. Box 4, Canberra A.C.T. 2600, Australia
R. B. Rickards
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, U.K.
P. R. Sheldon
Affiliation:
Department of Geology, University College, Cardiff CF1 1XL, U.K.
P. Toghill
Affiliation:
Department of Extra Mural Studies, Birmingham University, P.O. Box 363, Birmingham B15 2TT, U.K.
H. B. Whittington
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, U.K.
J. Zalasiewicz
Affiliation:
Institute of Geological Sciences, Keyworth, Nottingham NG12 5GG, U.K.
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Summary

Fission-track dating of zircons and apatites from tuffs and bentonites has produced the first isotopic ages for the type sections of the Ordovician and Silurian Systems. In the Ordovician the following ages have been determined: lower Arenig 493 Ma, lower Llanvirn 487 Ma, lower Llandeilo 477 Ma, upper Caradoc 463 Ma and upper Ashgill 434 Ma. In the Silurian, the following: lower Llandovery 437 Ma, lower Wenlock 422 Ma, upper Wenlock 414 Ma and Ludlow 407 Ma. The Ordovician-Silurian boundary is interpreted as occurring at about 436 Ma. Three North American Rocklandian bentonites yielded zircons whose ages average 453 Ma. This is about 10 Ma younger than supposedly correlative units in the British type sections.

Type
Articles
Information
Geological Magazine , Volume 119 , Issue 2 , March 1982 , pp. 135 - 153
Copyright
Copyright © Cambridge University Press 1982

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References

Bancroft, B. B. 1949. Upper Ordovician trilobites of zonal value in south-east Shropshire (ed. Lamont, A.). Proc. R. Soc. Lond. B 136, 291–315, pls 9–11.Google Scholar
Bassett, D. A., Whittington, H. B. & Williams, A. 1966. The stratigraphy of the Bala District, Merionethshire. Q. Jl geol. Soc. Lond. 122, 219–71.CrossRefGoogle Scholar
Bassett, M. G. 1979. Lithostratigraphy, Biostratigraphy and Chronostratigraphy: an example from the British Silurian. Izvest. Akad. Nauk. Kazakh. S.S.R. ser. geol. 4, 115–22.Google Scholar
Bassett, M. G., Cocks, L. R. M., Holland, C. H., Ingham, J. K., Lawson, J. D., Rickards, R. B. & Temple, J. T. 1979. Subcommission on Silurian Stratigraphy. Ordovician-Silurian Boundary Working Group. Field Meeting, Great Britain March 30-April 11, 1979. I.U.G.S. 1–48.Google Scholar
Bassett, M. G., Cocks, L. R. M., Holland, C. H., Rickards, R. B. & Warren, P. T. 1975. The Type Wenlock Series. Inst. Geol. Sci. Rep. 75–12, 1–19.Google Scholar
Bergström, S. M. 1971(a). Correlation of the North Atlantic Middle and Upper Ordovician conodont zonation with the graptolitic succession. Mem. Bur. Rech. geol. minier. 73, 177–87.Google Scholar
Bergström, S. M. 1971(b). Conodont biostratigraphy of the Middle and Upper Ordovician of Europe and eastern North America. Mem. geol. Soc. Am. 127, 83–157.Google Scholar
Bergström, S. 1980. Conodonts as paleotemperature tools in Ordovician rocks of the Caledonides and adjacent areas in Scandinavia and the British Isles. Geol. Fören. Stockh. Föorh. 102, 377–92.CrossRefGoogle Scholar
Bluck, B. J., Halliday, A. N., Aftalian, M. & Macintyre, R. M. 1980. Age and origin of Ballantrae ophiolite and its significance to the Caledonian orogeny and Ordovician time scale. Geology, 10, 492–5.2.0.CO;2>CrossRefGoogle Scholar
Brookins, D. G. 1976. Radiometric age determination of Silurian glauconite: Discussion. Bull. Am. Assoc. Petrol. Geol. 60, 883.Google Scholar
Byström-Asklund, A. M., Baadsgaard, H. & Folinsbee, R. E. 1961. K/Ar age of biotite, sanidine and illite from Middle Ordovician bentonites at Kinnekulle, Sweden. Geol. Fören, Stockh. Förh. 83, 92–6.CrossRefGoogle Scholar
Dean, W. T. 1963. The Ordovician trilobite faunas of South Shropshire, IV. Bull. Br. Mus. nat. Hist. (Geol.), 9, 1–18.Google Scholar
Elles, G. 1940. The stratigraphy and faunal succession in the Ordovician rocks of the Builth-Llandrindod Inlier, Radnorshire. Q. Jl geol. Soc. Lond. 95 (for 1939), 383–445.CrossRefGoogle Scholar
Epstein, A. G., Epstein, J. B. & Harris, L. D. 1974. Incipient metamorphism, structural anomalies, and oil and gas potential in the Appalachian basin determined from conodont color. Geol. Soc. Am. Abs. Prog. 6(7), 723–4.Google Scholar
Epstein, A. G., Epstein, J. B. & Harris, L. D. 1977. Conodont color alteration – an index to Organic Metamorphism. Prof. Paper U.S. geol. Surv. 995, 1–27.Google Scholar
Faul, H. 1960. Geologic Time Scale. Bull. geol. Soc. Am. 71, 637–44.CrossRefGoogle Scholar
Fearnsides, W. G. 1905. On the geology of Arenig Fawr and Moel Llyfnant. Q. Jl geol. Soc. Lond. 61, 608–40.CrossRefGoogle Scholar
Gale, N. H., Beckinsale, R. D. & Wadge, A. J. 1979. A Rb/Sr whole rock isochron for the Stockdale Rhyolite of the English Lake District and a revised mid-Palaeozoic time-scale. Jl geol. Soc. Lond. 136, 235–42.CrossRefGoogle Scholar
Gale, N. H., Beckinsale, R. D. & Wadge, A. J. 1980. Discussion of a paper by McKerrow, Lambert & Chamberlain on the Ordovician, Silurian and Devonian time scale. Earth Planet. Sci. Lett. 51, 9–17.CrossRefGoogle Scholar
Gleadow, A. J. W., Hurford, A. J. & Quaife, R. D. 1976. Fission-track dating of zircon: improved etching techniques. Earth Planet. Sci. Lett. 33, 273–6.CrossRefGoogle Scholar
Gleadow, A. J. W. & Lovering, J. F. 1977. Geometry factor of external detectors in fission-track dating. Nucl. Track Detect. 1, 99–109.CrossRefGoogle Scholar
Greig, D. C., Wright, J. E., Hains, B. A. & Mitchell, G. H. 1968. Geology of the Country around Church Stretton, Craven Arms, Wenlock Edge and Brown Clee. Mem. Geol. Surv. G.B. sheet 166, 1–379.Google Scholar
Holland, C. H. 1980. Silurian series and stages: decisions concerning chronostratigraphy. Lethaia 13, 238.CrossRefGoogle Scholar
Holland, C. H., Lawson, J. D. & Walmsley, V. G. 1963. The Silurian rocks of the Ludlow District, Shropshire. Bull. Br. Mus. nat. Hist. (Geol.) 8, 93–171.Google Scholar
Holland, C. H., Lawson, J. D., Walmsley, V. G. & White, D. E. 1980. Ludlow stages. Lethaia 13, 268.CrossRefGoogle Scholar
Hughes, C. P., Jenkins, C. J. & Rickards, R. B. 1981. Abereiddi Bay and the adjoining coast. In Geological excursions in Dyfed, Wales (ed. Bassett, M. G.), pp. 51–63. Cardiff: National Museum of Wales.Google Scholar
Hurst, J. M. 1979. The stratigraphy and brachiopods of the upper part of the type Caradoc of South Salop. Bull. Br. Mus. nat. Hist. (Geol.) 32, 183–304.Google Scholar
Izett, G. A., Naeser, C. W. & Obradovich, J. D. 1978. Ages of natural glasses by the fission-track and K-Ar methods. In Short Papers of the Fourth International Conference on Geochronology, Cosmochronology and Isotope Geology, Aspen, Colorado. U.S. Geol. Surv. Open-file Rept 78–701, 189–92.Google Scholar
Jones, O. T.& Pugh, W. J. 1948. The form and distribution of dolerite masses in the Builth-Llandrindod inlier, Radnorshire. Q. Jl geol. Soc. Lond. 104, 71–98.CrossRefGoogle Scholar
Jones, O. T. & Pugh, W. J. 1949. An early Ordovician shoreline in Radnorshire, near Builth Wells. Q. Jl Geol. Soc. Lond. 105, 65–99.CrossRefGoogle Scholar
Lanphere, M. A., Churkin, M. & Eberlein, G. D. 1977. Radiometric age of the Monograptus cyphus zone in southeastern Alaska – an estimate of the age of the Ordovician-Silurian Boundary. Geol. Mag. 114, 15–24.CrossRefGoogle Scholar
Lapworth, C. 1878. The Moffat Series. Q. Jl geol. Soc. Lond. 34, 240–346.CrossRefGoogle Scholar
McKerrow, W. S., Lambert, R. St. J. & Chamberlain, V. E. 1980. The Ordovician, Silurian and Devonian time scale. Earth Planet. Sci. Lett. 51, 1–8.CrossRefGoogle Scholar
Naeser, C. W. 1979. Fission-track dating and geologic annealing of fission tracks. In Lectures in Isotope Geology (ed. äger, E. J. and Hunziker, J. C.), pp. 154–69. New York.CrossRefGoogle Scholar
Naeser, C. W., Johnson, N. M.& McGee, V. E. 1978. A practical method of estimating standard error of age in the fission-track dating method. In Short Papers of the Fourth International Conference on Geochronology, Cosmochronology, and Isotope Geology, Aspen, Colorado. U.S. Geol. Surv. Open-file Rept 78–701, 303–4.Google Scholar
Naeser, W. E., Toghill, P. & Ross, R. J. Jr., 1982. Fission-track ages from the Precambrian of Shropshire. Geol. Mag. 119, 213–14.CrossRefGoogle Scholar
Obradovich, J. D. & Cobban, W. A. 1975. A time-scale for the late Cretaceous of the Western Interior of North America. Spec. Pap. geol. Ass. Can. 13, 31–54.Google Scholar
Ross, R. J. Jr., Naeser, C. W. & Izett, G. A. 1976. Apatite fission-track dating of a sample from the type Caradoc (Ordovician) series in England. Geology 4, 505–6.2.0.CO;2>CrossRefGoogle Scholar
Ross, R. J. Jr., Naeser, C. W., Izett, G. A., Whittington, H. B., Hughes, C. P., Rickards, R. B., Zalasiewicz, J., Sheldon, P. R., Jenkins, C. J., Cocks, L. R. M., Bassett, M. G., Toghill, P., Dean, W. T. & Ingham, J. K. 1977. Fission-track dating of Lower Paleozoic bentonites in British stratotypes. 3rd. Int. Symp. Ordov. Syst. Prog. Abstr., Columbus, Ohio, p. 4.Google Scholar
Ross, R. J. Jr., Naeser, C. W., Izett, G. A., Whittington, H. B., Hughes, C. P., Rickards, R. B., Zalasiewicz, J., Sheldon, P. R., Jenkins, C. J., Cocks, L. R. M., Bassett, M. G., Toghill, P., Dean, W. T. & Ingham, J. K. 1978. Fission-track dating of Lower Paleozoic volcanic ashes in British stratotypes. In Short Papers of the Fourth International Conference on Geochronology, Cosmochronology, and Isotope Geology, Aspen, Colorado. U.S. Geol. Surv. Open-file Rept. 78–701, 363–5.Google Scholar
Ross, R. J. Jr., Naeser, C. W. & Lambert, R. St. J. 1978. Ordovician Geochronology. In Contributions to the Geologic Time Scale (ed. Cohee, G. V., Glaessner, M. F. and Hedberg, H. D.). Studies in Geology No. 6, 347–54. Am. Assoc. Petrol. Geol.Google Scholar
Sanford, J. T. & Mosher, R. E. 1975. Radiometric age determination of Silurian glauconite. Bull. Am. Assoc. Petrol. Geol. 59, 1201–3.Google Scholar
Sanford, J. T. & Mosher, R. E. 1976. Radiometric age determination of Silurian glauconite: Reply. Bull. Am. Assoc. Petrol Geol. 60, 884.Google Scholar
Shergold, J. H. & Shirley, J. 1968. The faunal-stratigraphy of the Ludlovian rocks between Craven Arms and Bourton, near Much Wenlock, Shropshire. Geol. Jl 6, 119–38.CrossRefGoogle Scholar
Steiger, R. H. & Jäger, E. 1978. Subcommission on Geochronology: Convention on the use of decay constants in geochronology and cosmochronology. In Contributions to the Geologic Time Scale (ed. Cohee, G. V., Glaessner, M. F. and Hedberg, H. D.). Studies in Geology No. 6, 67–711. Am. Assoc. Petrol. Geol.Google Scholar
Van Schmuss, W. R., Thurman, E. M. & Peterman, Z. E. 1975. Geology and Rb/Sr chronology of middle Precambrian rocks in east central Wisconsin. Bull. geol. Soc. Am. 86, 1220–65.2.0.CO;2>CrossRefGoogle Scholar
Vidal, P., Auvray, B., Charlot, R., Fediuk, F., Hameurt, J. & Waldhausrova, J. 1975. Radiometric age of volcanics of the Cambrian ‘Krivoklat-Rokycany’ Complex (Bohemian Massif). Geol. Rdsch. 64, 563–71.CrossRefGoogle Scholar
White, D. E. & Lawson, J. D. 1978. The stratigraphy of new sections in the Ludlow Series of the type area, Ludlow, Salop, England. Inst. Geol. Sci. Rep. 78/30, 1–10.Google Scholar
Whittard, W. F. 1955–1967. The Ordovician trilobites of the Shelve Inlier. Parts I-IX. Palaeontogr. Soc. [Monogr.] (London).CrossRefGoogle Scholar
Whittard, W. F. 1979. An account of the Ordovician rocks of the Shelve Inlier in west Salop and part of north Powys (Compiled by W. T. Dean). Bull. Br. Mus. nat. Hist. (Geol.) 33, 1–69.Google Scholar
Whittington, H. B. 1966. Trilobites of the Henllan Ash, Arenig Series, Merioneth. Bull. Br. Mus. nat. Hist. (Geol.) 11, 489–505.Google Scholar
Williams, A. 1948. The Lower Ordovician cryptolithids of the Llandeilo district. Geol. Mag. 85, 65–88.CrossRefGoogle Scholar
Williams, A. 1953. The geology of the Llandeilo district, Carmarthenshire. Q. Jl geol. Soc. Lond. 108, 177–208.CrossRefGoogle Scholar
Williams, A. 1969. Ordovician of the British Isles. In North Atlantic geology and continental drift: a symposium, (ed. Kay, M.). Mem. Am. Assoc. Petrol. Geol. 12, 236–64.Google Scholar
Williams, A. 1974. Ordovician Brachiopods from the Shelve District, Shropshire. Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 11, 1–163.Google Scholar
Williams, A. Strachan, I., Bassett, D. A., Dean, W. T., Ingham, J. K., Wright, A. D. & Whittington, H. B. 1972. A correlation of Ordovician rocks in the British Isles. Spec. Rept. geol. Soc. Lond. 3, 1–74.Google Scholar