Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-07T20:09:28.424Z Has data issue: false hasContentIssue false
  • English
  • Français

Conodont Colour Alteration Index (CAI) values for the Carboniferous of Scotland

Published online by Cambridge University Press:  03 November 2011

Mark T. Dean  and
Nicholas Turner
Mark T. Dean
Affiliation:
British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, Scotland, UK
Nicholas Turner
Affiliation:
British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham, NG12 5GG, England, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Conodont elements from Scottish Carboniferous rocks have been reviewed for Colour Alteration Index(CAI) data, and most values range between 1 and 1·5. Assuming a local average geothermal gradient similar to that of today, the observed and predicted CAI values generally fit well. Only a few of the samples analysed were influenced by local igneous intrusives. The CAI range shown lies within the immature (early dry gas) to mature (perhapsmid-oil window) stages of hydrocarbon generation, and this suggests that burial maturation (where CAI values are 1-5) could account for locally generated oil, where this occurred away from igneous intrusions. Alkali-dolerite and tholeiitic intrusives are, however, widespread in the Midland Valley of Scotland, and an understanding of their thermal effects has implications for both coal and petroleum exploration. The insensitivity of conodonts to low temperatures is noted, and the relevance, application and potential of various other palaeothermometers is discussed. Locally, the qualitative study of spore colour (SCI) appears useful.

Keywords

hydrocarbonsigneous intrusionsmaturationpalaeotemperatureSpore Colour Index
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 85 , Issue 3 , 1994 , pp. 211 - 220
Copyright
Copyright © Royal Society of Edinburgh 1994

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

Aldridge, R. J. 1986. Conodont palaeobiogeography and thermal maturation in the Caledonides. J GEOL SOC LONDON 143, 177–84.Google Scholar
Armstrong, H. A. & Purnell, M. A. 1993. Thermal maturation of the Lower Carboniferousstrata of the Northumberland Trough and Tweed Basin from conodont Colour Alteration Index (CAI) data. PROC YORKSHIRE GEOL SOC 49, 335–43.Google Scholar
Barnard, P. C, Collins, A. G. & Cooper, B. S. 1981. Generation of hydrocarbons–time, temperature and source rock quality. In Brooks, J. (ed.)Organic maturation studies and fossil fuel exploration, 337–42. London: Academic Press.Google Scholar
Bergström, S. M. 1980. Conodonts as paleotemperature tools in Ordovician rocks of the Caledonides and adjacent areas in Scandinavia and the British Isles. GEOL FOREN STOCKHOLM FORH 102, 377–92.Google Scholar
Beveridge, R., Brown, S., Gallagher, M. & Merritt, J. 1991. Economicgeology. In Craig, G. Y. (ed.)Geology of Scotland, 3rd edn, 545–95. London: The Geological Society.Google Scholar
Briggs, D. E. G., Clarkson, E. N. K. & Aldridge, R. J. 1983. The conodont animal. LETHAIA 16, 1–14.Google Scholar
British Geological Survey. 1988. Geothermal energy in the United Kingdom: review of the British Geological Survey's Programme 1984–1987. INVEST GEOTHERM POTENTIAL OF THE UK, BR GEOL SURV.Google Scholar
Browne, M. A. E., Robins, N. S., Evans, R. B.. Monro, S. K. & Robson, P. G. 1987. The Upper Devonian and Carboniferous sandstones of the Midland Valley of Scotland. INVEST GEOTHERM POTENTIAL OF THE UK, BR GEOL SURV.Google Scholar
Burley, A. J. & Edmunds, W. M. 1978. Catalogue of geothermal data for the land area of the United Kingdom. London: Department of Energy.Google Scholar
Burnett, R. D. 1985. Conodont diagenesis and metamorphis—investigations into chemico-physical aspects, with studies from Northern England. University of Sheffield PhD thesis (unpublished).Google Scholar
Carruthers, R. G., Caldwell, W., Bailey, E. M. & Conacher, H. R. J. 1927.The oil-shales of the Lothians. MEM GEOL SURV. SCOTLAND.Google Scholar
Chisholm, J. I., McAdam, A. D. & Brand, P. J. 1989. Lithostratigraphical classification of Upper Devonian and Lower Carboniferous rocks in the Lothians. BR GEOL SURV TECH REP WA/89/26.Google Scholar
Clarke, W. J. 1960. Scottish Carboniferous conodonts. TRANS EDINBURGH GEOL SOC 18, 1–31.Google Scholar
Collins, A. 1990. The 1–10 Spore Colour Index (SCI) scale: a universally applicable colour maturation scale, based on graded, picked palynomorphs. In Fermont, W. J. J. & Weegink, J. W. (eds) INT SYMP ORG PETROL. MEDED RIJKS GEOL DIENST 45, 39–47.Google Scholar
Conacher, H. R. J. 1923. Some occurrences of natural mineral oil in the Scottish shale fields. TRANS EDINBURGH GEOL SOC 11, 319–26.Google Scholar
Davies, A., McAdam, A. D. & Cameron, I. B. 1986. Geology of the Dunbar district. Sheet 33E and part of Sheet 41. MEM BR GEOL SURV. SCOTLAND.Google Scholar
Dean, M. T. 1987. Carboniferous conodonts from the Lower and Upper Limestone Groups of the Scottish Midland Valley. University of Nottingham M.Phil, thesis (unpublished).Google Scholar
Dean, M. T. 1992. Conodont colour maturation indices for the Carboniferous of west-central Scotland. In Parnell, J. (ed.)Basins on the Atlantic Seaboard: Petroleum Geology, Sedimentology and Basin Evolution, 21–3. GEOLSOC SPEC PUB 62.Google Scholar
Deegan, C. E. 1978. Interpretation of the shallow seismic data on Sheet 55°:N/6°W, with comments on the IGS seaborne magnetic results. In McLean, A. C. & Deegan, C. E. (eds)The solid geology of the Clyde Sheet (55°N/6°W). REP INST GEOL SCI 78/9, 49–64.Google Scholar
Duff, P.McL, D. 1983. Economic geology. In Craig, G. Y. (ed.) Geology of Scotland, 2nd edn, 425–54. Edinburgh: Scottish Academic Press.Google Scholar
Emeleus, C. H. 1991. Tertiary igneous activity. In Craig, G. Y. (ed.) Geology ofScotland, 3rd edn, 455–502. London: The Geological Society.Google Scholar
England, R. W. 1992. The genesis, ascent and emplacement of the Northern Arran Granite, Scotland:implications for granitic diapirism. GEOL SOC AM BULL 104, 606–14.Google Scholar
Epstein, A. G., Epstein, J. B. & Harris, L. D. 1977. Conodont color alteration—an index to organic metamorphism. US GEOL SURV, PROF PAP 995.Google Scholar
Fisher, M. J., Barnard, P. C. & Cooper, B. S. 1980. Organic maturation and hydrocarbon generation in the Mesozoic sediments of the Sverdrup Basin, Arctic Canada. PROC 4TH PALYNOL CONF (LUCKNOW 1977) 2, 581–8.Google Scholar
Forsyth, I. D. & Chisholm, J. I. 1968. Geological Survey boreholes in the Carboniferous of east Fife (1963–4). BULL GEOL SURV GR BR 28, 61–78.Google Scholar
Forsyth, I. D. & Chisholm, J. I., 1977. The Geology of East Fife. MEM GEOL SURV GR BR, SCOTLAND.Google Scholar
Francis, E. H. 1983a. Carboniferous. In Craig, G. Y. (ed.)Geology ofScotland, 2nd edn, 253–96. Edinburgh: Scottish Academic Press.Google Scholar
Francis, E. H. 1991. Carboniferous. In Craig, G. Y. (ed.)Geology of Scotland, 3rd edn, 347–392. London: The Geological Society.Google Scholar
Francis, E. H. 1991b. Carboniferous-Permian igneous rocks. In Craig, G. Y. (ed.)Geology of Scotland, 3rd edn, 393–420. London: The Geological Society.Google Scholar
George, S. C. 1993. Black sandstones in the Midland Valley of Scotland: thermally metamorphosed hydrocarbon reservoirs? TRANS R SOC EDINBURGH: EARTH SCI 84, 61–72.Google Scholar
George, T. N., Johnson, G. A. L., Mitchell, M., Prentice, J. E.Ramsbottom, W. H. C, Sevastopulo, G. D. & Wilson, R. B. 1976. A correlation of Dinantian rocks in the British Isles. GEOL SOC LONDON SPEC REP 7.Google Scholar
Gunn, W., Geike, A., Peach, B. N. & Harker, A. 1903. The geology of North Arran, South Bute, and the Cumbraes withparts of Ayrshire and Kintyre. MEM GEOL SURV. SCOTLAND.Google Scholar
Hallett, D., Durant, G. P. & Farrow, G. E. 1985. Oil exploration and production in Scotland. SCOTT J GEOL 21, 547–70.Google Scholar
Héroux, Y., Chagnon, A. & Bertrand, R. 1979. Compilation and correlation of major thermal maturation indicators. AM ASSOC PETROL GEOL BULL 63, 2128–44.Google Scholar
Hinde, G. J. 1900. Notes and descriptions of new species of Scotch Carboniferous conodonts. TRANS NAT HIST SOC GLASGOW 5, 338–46.Google Scholar
IGS boreholes 1976. INST GEOL SCI REP 77/10.Google Scholar
IGS boreholes 1977. INST GEOL SCI REP 78/21.Google Scholar
Jones, J. M. & Creaney, S. 1977. Optical character of thermally metamorphosed coals of Northern England. J MICROSCOPY 109, 105–18.Google Scholar
Landing, E. 1981. Conodont biostratigraphy and thermal color alteration indices of the upper St. Charles and lower Garden City Formations, Bear River Range, Northern Utah and Southeastern Idaho. OPEN FILE REP 81–740, US DEP INTERIOR. GEOL SURV.Google Scholar
Leitch, D. 1941. The Upper Carboniferous rocks of Arran. TRANS GEOL SOC GLASGOW 20, 141–54.Google Scholar
Lovell, J. P. B. 1983. Permian and Triassic. In Craig, G. Y. (ed.) Geology of Scotland, 2nd edn, 325–42. Edinburgh: Scottish Academic Press.Google Scholar
Marshall, J. E. A. 1991. Quantitative spore colour. J GEOL SOC. LONDON 148,223–33.Google Scholar
M'Callien, W. J. & Anderson, R. B. 1930. The Carboniferous sediments of Kintyre. TRANS R SOC EDINBURGH 56, 599–619.Google Scholar
McLean, A. C. & Deegan, C. E. 1978. A synthesis of the solid geology of the Firth of Clyde region. In McLean, A. C. & Deegan, C. E. (eds). The solid geology of the Clyde Sheet(55 N/6W). REP INST GEOL SCI 78/9, 93–114.Google Scholar
Neves, R., Gueinn, K. J., Clayton, G., Ioannides, N. S., Neville, R. S. W. & Kruszewska, K. 1973. Palynological correlations within the Lower Carboniferous of Scotland and Northern England. TRANS R SOC EDINBURGH 69, 23–70.Google Scholar
Nowlan, G. S. & Barnes, C. R. 1987. Application of conodont colour alteration indicesto regional and economic geology. In Austin, R. L. (ed.)Conodonts: Investigative techniques and applications,188–202. Chichester: Ellis Horwood.Google Scholar
Oliver, J. H., Smellie, J. L., Thomas, L. J., Casey, D. M., Kemp, A. E. S., Evans, L. J., Baldwin, J. R. & Hepworth, B. C. 1984. Early Palaeozoic metamorphichistory of the Midland Valley, Southern Uplands-Longford-Down Massif and the Lake District, British Isles. TRANS R SOC EDINBURGH: EARTH SCI 75, 245–58.Google Scholar
Parnell, J. 1984. Hydrocarbon minerals in the Midland Valley of Scotland, with particular reference to the Oil-Shale Group. PROC GEOL ASSOC 95, 275–85.Google Scholar
Ramsbottom, W. H. C, Calver, M. A., Eagar, R. M. C, Hodson, F., Holliday, D. W., Stubblefield, C. J. & Wilson, R. B. 1978. A correlation of Silesian rocks in the British Isles. GEOL SOC LONDON SPEC REP 10.Google Scholar
Raymond, A. C. & Murchison, D. G. 1988. Development of organic maturation in the thermal aureoles o sillsand its relation to sediment compaction. FUEL 67, 1599–608.Google Scholar
Raymond, A. C. & Murchison, D. G. 1991. The relationship between organic maturation, the widths of thermal aureoles and the thickness of sills in the Midland Valley of Scotland and Northern England. J GEOL SOC LONDON 148, 215–8.CrossRefGoogle Scholar
Rhodes, F. H. T., Austin, R. L. & Druce, E. C. 1969. British Avonian (Carboniferous) conodont faunas and their value in local and international correlation. BULL BR MUS (NAT HIST), LONDON SUPPL 5.Google Scholar
Simpson, J. B. & Richey, J. E. 1936. The geology of the Sanquhar coalfield and adjacent basin of Thornhill. MEM GEOL SURV. SCOTLAND.Google Scholar
Staplin, F. L. 1969. Sedimentary organic matter, organic metamorphism and oil and gas occurrences. BULL CAN PETROL GEOL 17, 47–66.Google Scholar
Staplin, F. L. 1977. Interpretation of thermal history from colour of paniculate organic matter–a review. PALYNOL 1, 9–18.CrossRefGoogle Scholar
Tait, D. 1926. On the occurrence of petroliferous sandstones in the Carboniferous rocks of Scotland and their relation to certain black sandstones. TRANS EDINBURGH GEOL SOC 12, 90–104.Google Scholar
Turner, N. & Spinner, E. 1990. Palynological evidence of the age of the Coal Measuresof the Titterstone Clee Coalfield, Shropshire. England. PROC YORKSHIRE GEOL SOC 48, 81–98.Google Scholar