Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-27T22:15:19.468Z Has data issue: false hasContentIssue false

Cummingtonite in the Dalradian of NE Scotland

Published online by Cambridge University Press:  05 July 2018

C. G. Smith
Affiliation:
British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, UK
E. R. Phillips*
Affiliation:
British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, UK
*
*E-mail: erp@bgs.ac.uk

Abstract

The first recorded occurrence of cummingtonite in the Scottish Dalradian is described. The mineral occurs in thin layers within a psammite-semipelite sequence forming the lower part of the Easdale Subgroup in which it coexists with bytownitic plagioclase, almandine-rich garnet and quartz. Textural and mineral chemical evidence suggest that the cummingtonite developed from hornblende during amphibolite-facies regional metamorphism. The protolith to this cummingtonite-bearing rock is believed to have been a basaltic tuff, possibly alkaline in character, containing a significant proportion of sedimentary detritus. The cummingtonite-bearing rock may provide the earliest record of basic volcanism in the Dalradian of the Ballater district.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

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

Ahmed-Said, Y. and Tanner, P.W.G. (2000) P-T conditions during emplacement, and D2 regional metamorphism, of the Ben Vuirich Granite, Perthshire, Scotland. Mineralogical Magazine, 64, 737753.CrossRefGoogle Scholar
Baker, A.J. and Droop, G.T.R. (1983) Grampian metamorphic conditions deduced from mafic granulites and sillimanite- K-feldspar gneisses in the Dalradian of Glen Muick, Scotland. Journal of the Geological Society of London, 140, 489–497.CrossRefGoogle Scholar
Chinner, G.A. and Hesseltine, F.J. (1979) The Grampian andalusite/ kyanite isograd. Scottish Journal of Geology, 137, 35–39.Google Scholar
Coats, J.S., Smith, C.G., Gallagher, M.J., May, F., McCourt, W.J., Parker, M.E. and Fortey, N.J. (1981) Stratabound barium-zinc mineralization in Dalradian schist near Aberfeldy, Scotland: Final Report. Mineral Reconnais sance Programme Report, Institute of Geological Sciences, No. 40.Google Scholar
Collins, R.S. (1942) Cummingtonite and gedrite from Sutherland. Mineralogical Magazine, 26, 254259.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1962) Rock-forming Minerals: Volume 2, Chain Silicates. Longman, London, p. 379.Google Scholar
Dempster, T.J. and Harte, B. (1986) Polymetamorphism in the Dalradian of the Central Scottish Highlands. Geological Magazine, 123, 95104.CrossRefGoogle Scholar
Droop, G.T.R. (1987) A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses using stoichiometric criteria. Mineralogical Magazine, 51, 431435.CrossRefGoogle Scholar
Goodman, S. and Winchester, J.A. (1993) Geochemical variations within metavolcanic rocks of the Dalradian Farragon Beds and adjacent formations. Scottish Journal of Geology, 29, 113208.CrossRefGoogle Scholar
Graham, C.M. (1976) Petrochemistry and tectonic significance of Dalradian metabasaltic rocks of the SW Scottish Highlands. Journal of the Geological Society of London, 132, 6184.CrossRefGoogle Scholar
Harris, A.L., Bradbury, H.J. and McGonigal, M.H. (1976) The evolution and transport of the Tay Nappe. Scottish Journal of Geology, 12, 103113.CrossRefGoogle Scholar
Harris, A.L., Haselock, P.J., Kennedy, M.J. and Mendum, J R. (1994) The Dalradian Supergroup in Scotland, Shetland and Ireland. Pp. 3353 in: A Revised Correlation of Precambrian Rocks in the British Isles (Gibbons, W. and Harris, A.L., editors). Special Reports, 22. Geological Society, London.CrossRefGoogle Scholar
Harte, B., Booth, J.E., Dempster, T.J., Fettes, D.J., Mendum, J.R. and Watts, D. (1984) Aspects of the post-depositional evolution of Dalradian and Highland Border Complex rocks in the Southern Highlands of Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, 75, 151–163.Google Scholar
Hey, M. (1954) A new review of the chlorites. Mineralogical Magazine, 30, 277292.CrossRefGoogle Scholar
Johnson, T.E., Hudson, N.F.C. and Droop, G.T.R. (2000) Wollastonite-bearing assemblages from the Dalradian at Fraserburgh, northeast Scotland and their bearing on the emplacement of garnetiferous granitoid sheets. Mineralogical Magazine, 64, 11651176.CrossRefGoogle Scholar
Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., Gilbert, M.C., Grice, J.D., Hawthorne, F.C., Kato, A., Kisch, H.J., Krivovichev, V.G., Linthout, K., Laird, J., Mandarino, J., Maresch, W.V., Nickel, E.H., Rock, N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, N.C.N., Ungaretti, L., Whittaker, E.J.W. and Youzhi, G. (1997) Nomenclature of amphiboles: Report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names. Mineralogical Magazine, 61, 295321.CrossRefGoogle Scholar
Mather, J.D. (1970) The biotite isograd and the lower greenschist facies in the Dalradian of Scotland. Journal of Petrology, 11, 253275.CrossRefGoogle Scholar
Mendum, J.R. and Fettes, D.J. (1985) The Tay Nappe and associated folding in the Ben Ledi Loch Lomond area. Scottish Journal of Geology, 21, 4156.CrossRefGoogle Scholar
Meschede, P.J. (1986) A method of discriminating between different types of mid-ocean ridge basalts and continental tholeiites with the Nb-Zr-Y diagram. Chemical Geology, 56, 207–218.CrossRefGoogle Scholar
Misra, S.N. (1971) Chemical distinction of high-grade ortho- and para-metabasites. Norsk Geologisk Tidsskrift, 51, 311316.Google Scholar
Miyashiro, A. (1958) Regional metamorphism of the Gosaisayo-Takanuki district in the Central Abukuma Plateau. Journal of the Faculty of Science University of Tokyo, Section II, 11, 249.Google Scholar
Munro, M. (1986) Geology of the country around Aberdeen. Memoir of the British Geological Survey. Sheet 77 (Scotland).Google Scholar
Pearce, J.A. and Norry, M.J. (1979) Petrogenetic implications of Ti, Zr, Y and Nb variations in volcanic rocks. Contributions to Mineralogy and Petrology, 69, 3347.CrossRefGoogle Scholar
Pickett, E. (1997) An introduction to the Green Beds of the Southern Highland Group of the Scottish Dalradian: previous research and an account of preliminary work carried out in 1997. British Geological Survey, Technical Report, WA/97/92.Google Scholar
Robertson, S. (1994) Timing of Barrovian metamorphism and ‘Older Granite’ emplacement in relation to Dalradian deformation. Journal of the Geological Society of London, 151, 58.CrossRefGoogle Scholar
Shido, F. (1958) Plutonic and metamorphic rocks of the Nakoso and Iritono districts in the Central Abukuma Plateau. Journal of the Faculty of Science, University of Tokyo, Section II, 11, 131.Google Scholar
Sivaprakash, C. (1982) Geothermometry and geobarometry of Dalradian metapelites and metabasites from the central Scottish Highlands. Scottish Journal of Geology, 18, 109124.CrossRefGoogle Scholar
Smith, C.G., Goodman, S. and Robertson, S. (in press) Geology of the Ballater district, Sheet 65E (Scotland). Memoir of the British Geological Survey.Google Scholar
Stephenson, D. (1993) Amphiboles from Dalradian metasedimentary rocks of NE Scotland. Mineralogy and Petrology, 49, 4562.CrossRefGoogle Scholar
Stephenson, D. and Gould, D. (1995) British Regional Geology: The Grampian Highlands (Fourth Edition). London, HMSO for the British Geological Survey.Google Scholar
Tilley, C.E. (1938) Cummingtonite-bearing rocks from the Lewisian. Geological Magazine, 75, 7681.CrossRefGoogle Scholar
Van de Kamp, P.C. (1970) The Green Beds of the Scottish Dalradian series: geochemistry, origin and metamorphism of mafic sediments. Journal of Geology, 78, 281–303.CrossRefGoogle Scholar
Veblen, D.R. (editor) (1981) Amphiboles and other Hydrous Pyriboles – Mineralogy. Reviews in Mineralogy, 9a. Mineralogical Society of America, Washington D.C., p. 372.CrossRefGoogle Scholar
Watters, W.A. (1959) An association of hornblende and cummingtonite from Ringaringa. Stewart Island, New Zealand. New Zealand Journal of Geology and Geophysics, 2, 248–56.CrossRefGoogle Scholar
Winchester, J.A. and Floyd, P.A. (1977) Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chemical Geology, 20, 325343.CrossRefGoogle Scholar