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The Portsoy–Duchray Hill Lineament: a review of the evidence

Published online by Cambridge University Press:  01 May 2009

S. Goodman
Affiliation:
Department of Geology & Petroleum Geology, Aberdeen University, King's College, Aberdeen AB9 2UE, U.K.

Abstract

The Portsoy–Duchray Hill Lineament has been widely quoted in the literature as a major zone of discontinuities, running from Portsoy on the Banff coast to the Duchray Hill area in Perthshire. A review of the evidence indicates that there is no single structural entity running from Portsoy to Duchray Hill; the term ‘Portsoy-Duchray Hill lineament’ should be avoided. There are, however, significant along- and across-strike variations in geological history across a zone which extends from Portsoy to the Cabrach (the ‘Portsoy Line’). Certain elements can be identified also in areas further south, e.g. the Coyles of Muick shear zone and Glen Doll fault.

The Portsoy Line was initiated as a zone of syn-depositional faulting, with resulting facies variations similar to those seen across the Glen Doll fault. The Portsoy Line was reactivated as a ductile shear zone during Caledonian orogenesis, while the Glen Doll fault is a later, more brittle, structure. The shear zone from Portsoy to the Cabrach forms the western branch of a system of shears which acted to focus syn-orogenic basic magmatism, and differential movement during post- metamorphic uplift. The Coyles of Muick shear zone is the most southerly example of the system of shears, and there is probably a transfer zone along Deeside between it and the Portsoy-Cabrach shear zone, now obscured in part by the Ballater Granite. The focused shear zones serve to delineate the Buchan area, with its low pressure metamorphism and distinctive structural style, from areas to the south and west where the structural level was deeper, and deformation more pervasive.

Type
Articles
Copyright
Copyright © Cambridge University Press 1994

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References

Anderton, R. 1985. Sedimentation and tectonics in the Scottish Dalradian. Scottish Journal of Geology 21, 407–36.Google Scholar
Ashcroft, W. A., Kneller, B. C., Leslie, A. G. & Munro, M. 1984. Major shear zones and autochthonous Dalradian in the north-east Caledonides. Nature 310, 760–62.Google Scholar
Ashworth, J. R. 1975. The sillimanite zones in the Huntly–Portsoy area in the north-east Dalradian, Scotland. Geological Magazine 112, 113–36.Google Scholar
Ashworth, J. R. 1976. Petrogenesis of migmatities in the Huntly–Portsoy area, north-east Scotland. Mineralogical Magazine 40, 661–82.CrossRefGoogle Scholar
Atherton, M. P. 1977. The metamorphism of the Dalradian rocks of Scotland. Scottish Journal of Geology 13, 331–70.Google Scholar
Baker, A. J. 1985. Pressures and temperatures of metamorphism in the eastern Dalradian. Journal of the Geological Society, London 142, 137–48.CrossRefGoogle Scholar
Baker, A. J. 1987. Models for the tectonothermal evolution of the eastern Dalradian of Scotland. Journal of Metamorphic Geology 5, 101–18.Google Scholar
Baker, A. J. & Droop, G. T. R. 1983. Grampian meta-morphic conditions deduced from mafic granulites and sillimanite-K-feldspar gneisses in the Dalradian of Glen Muick, Scotland. Journal of the Geological Society, London 140, 489–97.Google Scholar
Barrow, G. 1912. On the geology of lower Deeside and the Southern Highland Border. Proceedings of the Geologists' Association 23, 268–73.CrossRefGoogle Scholar
Beddoe-Stephens, B. 1990. Pressures and temperatures of Dalradian metamorphism and the andalusite–kyanite transformation in the northeast Grampians. Scottish Journal of Geology 26, 314.Google Scholar
Chinner, G. 1961. The origin of sillimanite in Glen Clova, Angus. Journal of Petrology 2, 312–23.CrossRefGoogle Scholar
Chinner, G. 1980. Kyanite isograds of Grampian metamorphism. Journal of the Geological Society, London 137, 35–9.Google Scholar
Crowley, P. D. 1991. Thermal and kinetic constraints on the tectonic applications of thermobarometry. Mineralogical Magazine 55, 5769.CrossRefGoogle Scholar
Dempster, T. J. 1985. Uplift patterns and orogenic evolution in the Scottish Dalradian. Journal of the Geological Society, London 142, 111–28.Google Scholar
Dempster, T. J. & Harte, B. 1986. Polymetamorphism in the Dalradian of the central Scottish Highlands. Geological Magazine 123, 95104.Google Scholar
Fettes, D. J. & Harris, A. L. 1986. The Caledonian Geology of the Scottish Highlands. In Synthesis of the Caledonian Rocks of Britain (ed. Fettes, D. J. & Harris, A. L.), pp. 303–34. D. Reidel Publishing Company.CrossRefGoogle Scholar
Fettes, D. J., Graham, C. M., Harte, B. & Plant, J. A. 1986. Lineaments and basement domains: an alternative view of Dalradian evolution. Journal of the Geological Society, London 143, 453–64.Google Scholar
Fettes, D. J., Leslie, A. G., Stephenson, D. & Kimbell, S. F. 1991. Disruption of Dalradian stratigraphy along the Portsoy Lineament from new geological and magnetic surveys. Scottish Journal of Geology 27, 5773.Google Scholar
Fletcher, T. A. & Rice, C. M. 1989. Geology, mineralization (Ni–Cu) and precious metal geochemistry of Caledonian mafic and ultramafic intrusions near Huntly, northeast Scotland. Transactions of the Institute of Mining and Metallurgy (Section B: Applied earth sciences) 98, B185200.Google Scholar
Garson, M. S. & Plant, J. 1973. Alpine type ultramafic rocks and episodic mountain building in the Scottish Highlands. Nature, Physical Sciences 242, 34–8.Google Scholar
Ghent, E. D. & Stout, M. Z. 1981. Geobarometry and geothermometry of plagioclase–biotite–garnet–muscovite assemblages. Contributions to Mineralogy and Petrology 76, 92–7.Google Scholar
Goodman, S. 1991. The Pannanich Hill Complex and the origin of Crinan Subgroup migmatites in the North-eastern and Central Highlands. Scottish Journal of Geology 27, 147–56.Google Scholar
Graham, C. M. 1986. The role of the Cruachan Lineament during Dalradian evolution. Scottish Journal of Geology 22, 257–70.Google Scholar
Harris, A. L. (ed.) 1985. The nature and timing of orogenic activity in the Caledonian rocks of the British Isles. Geological Society of London Memoir, No. 9.Google Scholar
Harris, A. L. & Pitcher, W. S. 1975. The Dalradian Supergroup. In A correlation of the Precambrian rocks of the British Isles (ed. Harris, A. L., Shackleton, R. M., Watson, J., Downie, C., Harland, W. B. and Moorbath, S.), pp. 5275. Special Report of the Geological Society of London, No. 6.Google Scholar
Harte, B. 1979. The Tarfside succession and the structure and stratigraphy of the eastern Scottish Dalradian rocks. In The Caledonides of the British Isles – reviewed (ed. Harris, A. L., Holland, C. H. and Leake, B. E.), pp. 221–8. Special Publication of the Geological Society of London, No. 8.Google Scholar
Harte, B. 1988. Lower Palaeozoic metamorphism in the Moine-Dalradin belt of the British Isles. In The Caledonian-Appalachian Orogen (eds Harris, A. L. and Fettes, D. J.), pp. 123–34. Special Publication of the Geological Society of London, No. 38.Google Scholar
Harte, B. & Hudson, N. F. C. 1979. Pelite facies series and the temperatures and pressures of Dalradian meta-morphism in E. Scotland. In The Caledonides of the British Isles – reviewed (eds. Harris, A. L., Holland, C. H. and Leake, B. E.), pp. 323–37. Special Publication of the Geological Society of London, No. 8.Google Scholar
Harte, B., Booth, J. E., Dempster, T. J., Fettes, D. J., Mendum, J. R., 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, 151–63.Google Scholar
Hawson, C. A. & Hall, A. J. 1987. Middle Dalradian Corrycharmaig serpentinite, Perthshire, Scotland: an ultramafic intrusion. Transactions of the Institute of Mining and Metallurgy 96, B173–77.Google Scholar
Hodges, K. V. & Spear, F. S. 1982. Geothermometry, geobarometry and the Al2SiO5 triple points at Mt. Moosilauke, New Hampshire. American Mineralogist 67, 1118–34.Google Scholar
Hudson, N. F. C. 1985. Conditions of Dalradian meta-morphism in the Buchan area, NE Scotland. Journal of the Geological Society, London 142, 6376.CrossRefGoogle Scholar
Kneller, B. C. 1987. A Geological History of NE Scotland. In Geology of the Aberdeen area (eds Trewin, N. H., Kneller, B. C. and Gillen, C.), pp. 150. Edinburgh: Scottish Academic Press.Google Scholar
Kneller, B. C. & Leslie, A. G. 1984. Amphibolite facies metamorphism in shear zones in the Buchan area of NE Scotland. Journal of Metamorphic Geology 2, 8394.Google Scholar
McLellan, E. L. 1989. Sequential formation of subsolidus and anatectic migmatites in response to thermal evolution, eastern Scotland. Journal of Geology 97, 165–82.Google Scholar
Munro, M. 1970. A reassessment of the ‘younger’ basic igneous rocks between Huntly and Portsoy based on new borehole evidence. Scottish Journal of Geology 6, 4152.Google Scholar
Newton, R. C. & Haselton, H. T. 1981. Thermodynamics of the garnet-plagioclase-Al2Si05-quartz geobaro-meter. In Thermodynamics of Minerals and Melts (eds Newton, R. C., Navrotsky, A. and Wood, B. J.), pp. 131–48. New York: Springer Verlag.CrossRefGoogle Scholar
Pankhurst, R. J. 1970. The geochronology of the basic igneous complexes. Scottish Journal of Geology 6, 83107.CrossRefGoogle Scholar
Ramsay, D. M. & Sturt, B. A. 1979. The status of the Banff nappe. In The Caledonides of the British Isles – reviewed (eds Harris, A. L., Holland, C. H. and Leake, B. E.), pp. 145–52. Special Publication of the Geological Society of London, No. 8.Google Scholar
Read, H. H. 1923. The geology around Banff, Huntly and Turriff. Memoir of the Geological Survey of Scotland (Sheets 86 & 96).Google Scholar
Read, H. H. 1955. The Banff Nappe: an interpretation of the structure of the Dalradian rocks of north-east Scotland. Proceedings of the Geologists' Association 66, 129.CrossRefGoogle Scholar
Roberts, J. L. & Treagus, J. 1979. Stratigraphical and structural correlation between the Dalradian rocks of the SW and Central Highlands of Scotland. In The Caledonides of the British Isles – reviewed (eds Harris, A. L., Holland, C. H. and Leake, B. E.), pp. 199204. Special Publication of the Geological Society of London, No. 8.Google Scholar
Robertson, S. 1988. Relationships between ‘younger’ and ‘older basics’ in the Glen Gairn area, North Deeside. Scottish Journal of Geology 24, 8992.Google Scholar
Soper, N. J. & Anderton, R. 1984. Did the Dalradian slides originate as extensional faults? Nature 307, 357–9.Google Scholar
Wadsworth, W. J. 1982. The basic plutons. In Igneous Rocks of the British Isles (ed. Sutherland, D. S.), pp. 135–48. John Wiley & Sons.Google Scholar