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Fission-track dating of British Ordovician and Silurian stratotypes

  • R. J. Ross (a1), C. W. Naeser (a2), G. A. Izett (a2), J. D. Obradovich (a2), M. G. Bassett (a3), C. P. Hughes (a4), L. R. M. Cocks (a5), W. T. Dean (a6), J. K. Ingham (a7), C. J. Jenkins (a8), R. B. Rickards (a4), P. R. Sheldon (a6), P. Toghill (a9), H. B. Whittington (a4) and J. Zalasiewicz (a10)...

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.

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Bancroft, B. B. 1949. Upper Ordovician trilobites of zonal value in south-east Shropshire (ed. Lamont, A.). Proc. R. Soc. Lond. B 136, 291315, pls 9–11.
Bassett, D. A., Whittington, H. B. & Williams, A. 1966. The stratigraphy of the Bala District, Merionethshire. Q. Jl geol. Soc. Lond. 122, 219–71.
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.
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. 148.
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. 7512, 119.
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.
Bergström, S. M. 1971(b). Conodont biostratigraphy of the Middle and Upper Ordovician of Europe and eastern North America. Mem. geol. Soc. Am. 127, 83157.
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.
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.
Brookins, D. G. 1976. Radiometric age determination of Silurian glauconite: Discussion. Bull. Am. Assoc. Petrol. Geol. 60, 883.
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.
Dean, W. T. 1963. The Ordovician trilobite faunas of South Shropshire, IV. Bull. Br. Mus. nat. Hist. (Geol.), 9, 118.
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), 383445.
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.
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, 127.
Faul, H. 1960. Geologic Time Scale. Bull. geol. Soc. Am. 71, 637–44.
Fearnsides, W. G. 1905. On the geology of Arenig Fawr and Moel Llyfnant. Q. Jl geol. Soc. Lond. 61, 608–40.
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.
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, 917.
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.
Gleadow, A. J. W. & Lovering, J. F. 1977. Geometry factor of external detectors in fission-track dating. Nucl. Track Detect. 1, 99109.
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, 1379.
Holland, C. H. 1980. Silurian series and stages: decisions concerning chronostratigraphy. Lethaia 13, 238.
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, 93171.
Holland, C. H., Lawson, J. D., Walmsley, V. G. & White, D. E. 1980. Ludlow stages. Lethaia 13, 268.
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. 5163. Cardiff: National Museum of Wales.
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, 183304.
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 78701, 189–92.
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, 7198.
Jones, O. T. & Pugh, W. J. 1949. An early Ordovician shoreline in Radnorshire, near Builth Wells. Q. Jl Geol. Soc. Lond. 105, 6599.
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, 1524.
Lapworth, C. 1878. The Moffat Series. Q. Jl geol. Soc. Lond. 34, 240346.
McKerrow, W. S., Lambert, R. St. J. & Chamberlain, V. E. 1980. The Ordovician, Silurian and Devonian time scale. Earth Planet. Sci. Lett. 51, 18.
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.
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.
Naeser, W. E., Toghill, P. & Ross, R. J. Jr., 1982. Fission-track ages from the Precambrian of Shropshire. Geol. Mag. 119, 213–14.
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, 3154.
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.
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.
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.
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.
Sanford, J. T. & Mosher, R. E. 1975. Radiometric age determination of Silurian glauconite. Bull. Am. Assoc. Petrol. Geol. 59, 1201–3.
Sanford, J. T. & Mosher, R. E. 1976. Radiometric age determination of Silurian glauconite: Reply. Bull. Am. Assoc. Petrol Geol. 60, 884.
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.
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, 67711. Am. Assoc. Petrol. Geol.
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.
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.
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, 110.
Whittard, W. F. 19551967. The Ordovician trilobites of the Shelve Inlier. Parts I-IX. Palaeontogr. Soc. [Monogr.] (London).
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, 169.
Whittington, H. B. 1966. Trilobites of the Henllan Ash, Arenig Series, Merioneth. Bull. Br. Mus. nat. Hist. (Geol.) 11, 489505.
Williams, A. 1948. The Lower Ordovician cryptolithids of the Llandeilo district. Geol. Mag. 85, 6588.
Williams, A. 1953. The geology of the Llandeilo district, Carmarthenshire. Q. Jl geol. Soc. Lond. 108, 177208.
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.
Williams, A. 1974. Ordovician Brachiopods from the Shelve District, Shropshire. Bull. Br. Mus. nat. Hist. (Geol.) Suppl. 11, 1163.
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, 174.

Fission-track dating of British Ordovician and Silurian stratotypes

  • R. J. Ross (a1), C. W. Naeser (a2), G. A. Izett (a2), J. D. Obradovich (a2), M. G. Bassett (a3), C. P. Hughes (a4), L. R. M. Cocks (a5), W. T. Dean (a6), J. K. Ingham (a7), C. J. Jenkins (a8), R. B. Rickards (a4), P. R. Sheldon (a6), P. Toghill (a9), H. B. Whittington (a4) and J. Zalasiewicz (a10)...

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