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Thorium–bitumen mineralization in Silurian sandstones, Welsh Borderland

Published online by Cambridge University Press:  05 July 2018

John Parnell
Affiliation:
Department of Geology, Queen's University, Belfast BT7 1NN, U.K.
Paul Eakin
Affiliation:
Department of Geology, Queen's University, Belfast BT7 1NN, U.K.

Abstract

The Llandovery Folly Sandstone near Presteigne, Powys, contains disseminated thorium mineralization. The thorium occurs as inclusions of thorite and thorianite within sub-millimetre-scale bitumen nodules throughout the sandstone. The nodules grew replacively in situ. The two square kilometres outcrop/subcrop of the sandstone may contain over 500 tonnes thorium.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1989

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References

Ball, T. K. and Nutt, M. J. C. (1975) Preliminary mineral reconnaissance in central Wales. Rep. Inst. Geol. Sei. 75/14.Google Scholar
Bath, A. H., Brassell, S. C., Eglinton, G., Hill, R. I., Hooker, P. J., O'Nions, R. K., Oxburgh, E. R., Parnell, J., Robinson, N., and Spiro, B. (1986) Deep source gases and hydrocarbons in the U.K. crust. Rep. Fluid Processes Res. Group Br. Geol. Surv. FLPU86-2.Google Scholar
Boyle, R. W. (1982) Geochemical prospecting for thorium and uranium deposits. Elsevier.Google Scholar
Curiale, J. A., Bloch, S., Rafalska-Bloch, J., and Harrison, W. E. (1983) Petroleum-related origin for uraniferous organic-rich nodules of southwestern Oklahoma. Bull. Am. Assoc. Petrol. Geol. 67, 588-608.Google Scholar
Davidson, C. F. and Bowie, S. H. U. (1951) On thucholite and related hydrocarbon-uraninite complexes. Geol. Surv. Great Br. Bull. 3, 1-18.Google Scholar
Davies, J. H., Holroyd, J., Lumley, R. G., and Owen-Roberts, D. (1983) Geology of Powys in Outcrop. Merioneth Press.Google Scholar
Harrison, R. K. (1970) Hydrocarbon bearing nodules from Heysham, Lancashire. Geol. J. 7, 101-10.CrossRefGoogle Scholar
Harrison, R. K., Old, R. A., Styles, M. T., and Young, B. R. (1983) Coffinite in nodules from the Mercia Mudstone Group (Triassic) of the I.G.S. Knowle borehole, West Midlands. Rep. Inst. Geol. Sci. 83/10, 12-16.Google Scholar
Heinrich, E. W. (1958) Mineralogy and geology of radioactive raw materials. McGraw-Hill.Google Scholar
Kirk, N. H. (1951) The Upper Llandovery and Lower Wenlock rocks of the area between Dolyhir and Presteigne, Radnorshire. Proc. Geol. Soc. Lond. no. 1471, 56-8.Google Scholar
Lambert, R. St. J. and Holland, J. G. (1971) The petrography and chemistry of the igneous complex of the Malvern Hills, England. Proe. Geol. Ass. 82, 323-52.CrossRefGoogle Scholar
Parnell, J. (1983) The distribution of hydrocarbon minerals in the Welsh Borderlands and adjacent areas. Geol. J. 18, 129-39.CrossRefGoogle Scholar
Parnell, J. (1985) Uranium/rare earth-enriched hydrocarbons in Devonian sandstones, northern Scotland. Neues Jahrb. Mineral. Mh. 132 44.Google Scholar
Parnell, J. (1987) Secondary porosity in hydrocarbon-bearing transgressive sandstones on an unstable Lower Palaeozoic continental shelf, Welsh Borderland. Geol. Soc. London Spec. Publ. 36, 297-312.CrossRefGoogle Scholar
Parnell, J. and Eakin, P. (1987) The replacement of sandstones by uraniferous hydrocarbons: significance for petroleum migration. Mineral. Mag. 51, 505-15.CrossRefGoogle Scholar
Roberts, W. H. (1980) Design and function of oil and gas traps. AAPG Studies in Geology, 10, 317-40.Google Scholar
Read, D., Cooper, D. C., and McArthur, J. M. (1987) The composition and distribution of nodular monazite in the Lower Palaeozoic rocks of Great Britain. Mineral. Mag. 51, 271-80.CrossRefGoogle Scholar
Schidlowski, M. (1975) Uraniferous constituents of the Witwatersrand conglomerates: ore-microscopic observations and implications for the Witwatersrand metallogeny. United States Geol. Surv. Prof. Paper, 116IN, 1-23.Google Scholar
Welin, E. (1964) Uranium disseminations and vein fillings in iron ores of northern Uppland, Central Sweden. Geol. Fören. Stockh. Fdrhandl. 86, 51-82.CrossRefGoogle Scholar
Welin, E. (1966a) Two occurrences of uranium in Sweden— The Los cobalt deposit and the iron ores of the Vastervik area. Ibid. 87, 492-508.CrossRefGoogle Scholar
Welin, E. (1966b) Uranium mineralization and age relationships in the Precambrian bedrock of central and southeastern Sweden. Ibid. 88, 34-67.CrossRefGoogle Scholar
Ziegler, A. M. (1966) Unusual Stricklandiid brachiopods from the Upper Llandovery beds near Presteigne, Radnorshire. Palaeontology, 9, 346-50.Google Scholar
Ziegler, A. M. Cocks, L. R. M., and McKerrow, W. S. (1968) The Llandovery transgression of the Welsh Borderland. Ibid. 11, 736-82.Google Scholar