Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-11T10:41:55.641Z Has data issue: false hasContentIssue false

Microdiorite sheet intrusions as incompetent time- and strain-markers in the Moine assemblage NW of the Great Glen fault, Scotland

Published online by Cambridge University Press:  03 November 2011

C. J. Talbot
Affiliation:
University of Uppsala, Institute of Geology, Department of Mineralogy and Petrology, Box 555, S-751 22 Uppsala, Sweden.

Abstract

Radiometrie evidence suggests a complex evolution for some parts of the Moine assemblage NW of the Great Glen fault in Scotland. Four generations of microdiorite sheet intrusions are distinguished and used as time- and strain-markers in this region. Two are found to record different tectonic episodes in the Morar and Glenfinnan divisions and their Loch Eil division cover during the c 750 Ma Knoydartian orogeny. These demonstrate that F1 and F2 (of the Grenvillian orogeny) and F3 folds (of the Knoydartian orogeny) in the Morar and Glenfinnan divisions are absent from the Loch Eil division. Two later generations of microdiorites record successive episodes (F4 and F5) of the c. 455 Ma Caledonian orogeny.

The tectonic history of the region is considered after a discussion of the use of microdiorite sheet intrusions as strain-markers. This is because, rather than fold or boudinage, they deformed as incompetent single layers and foliated, mullioned or thinned uniformly instead. The attitudes of different elements of the microdiorites and their internal foliation are used to construct strain ellipsoids for four tectonic episodes on scales of 4–400 m and >4000 m. Three of these episodes are found empirically to have involved irrotational plane strain and all are close to coaxial even though the principal axes of strain appear to have swapped one for another in space as well as time.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1983

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

11. References

Aftalion, M. & van Breemen, O. 1980. U–Pb zircon, monazite and Rb–Sr whole rock systematics of granitic gneiss and psammitic to semi-pelitic host gneiss from Glenfinnan, northwestern Scotland. CONTRIB MINERAL PETROL 72, 8798.CrossRefGoogle Scholar
Allaart, J. H. 1967. Basic and intermediate igneous activity and its evolution of the Julianehåb Granite, South Greenland. MEDDR GRØNLAND 175, 1136.Google Scholar
Baird, A. W. 1982. The structural setting of the Sgurr Beag Slide within the Moine rocks of western Inverness-shire, Scotland. J GEOL SOC LONDON 139, 647653.CrossRefGoogle Scholar
Berger, A. R. 1971. Dynamic analysis using dikes with oblique internal foliations. BULL GEOL SOC AM 82, 781786.CrossRefGoogle Scholar
Bowes, D. R. 1968. The absolute time scale and the subdivision of the Precambrian rocks of Scotland. FORH GEOL FOREN STOCKHOLM 90, 175–88.CrossRefGoogle Scholar
Bowes, D. R. & Gaál, G. 1981. Precambrian record of the eastern North Atlantic Borderlands. In Kerr, J. W. & Fergusson, A. J. (eds) Geology of the North Atlantic Borderlands, 3155. MEM CAN SOC PET GEOL 7.Google Scholar
Brewer, M. S., Brook., M. & Powell, D. 1979. Dating of the tectonometamorphic history of the southwestern Moine, Scotland. In Harris, A. L.et al. (eds) The Caledonides of the British Isles – reviewed. SPEC PUBL GEOL SOC LONDON 8, 129–37.Google Scholar
Brook, M., Brewer, M. S. & Powell, D. 1976. Grenville ages for rocks in the Moine of north-western Scotland. NATURE LONDON 260, 515–17.CrossRefGoogle Scholar
Brook, M., Powell, D. & Brewer, M. S. 1977. Grenville events in Moine rocks of the Northern Highlands, Scotland. J GEOL SOC LONDON 133, 489–96.CrossRefGoogle Scholar
Brown, R. L., Dalziel, I. W. D. & Johnson, M. R. W. 1970. A review of the structure and stratigraphy of the Moinian of Ardgour, Moidart and Sunart–Argyll and Inverness-shire. SCOTT J GEOL 6, 309–35.CrossRefGoogle Scholar
Chapple, W. M. 1970. The finite-amplitude instability in the folding of layered rocks. CAN J EARTH SCI 7, 457–67.CrossRefGoogle Scholar
Cheeney, R. F. & Mathews, D. W. 1965. The structural evolution of the Tarskavaig and Moine nappes in Skye. SCOTT J GEOL 1, 256–81.CrossRefGoogle Scholar
Dalziel, I. W. D. 1966. A structural study of the granitic gneiss of western Ardgour, Argyll and Inverness-shire. SCOTT J GEOL 2, 125–52.CrossRefGoogle Scholar
Davidson, L. M. & Park, R. G. 1978. Late Nagssugtoqidian stress orientation derived from deformed granodiorite dykes north of Holsteinsborg, West Greenland. J GEOL SOC LONDON 135, 283–9.CrossRefGoogle Scholar
Flinn, D. 1962. On folding during three dimensional progressive deformation. Q J GEOL SOC LONDON 118, 385433.CrossRefGoogle Scholar
Giletti, B. J., Moorbath, S. & Lambert, R. St J. 1961. A geochronological study of the metamorphic complexes of the Scottish Highlands. Q J GEOL SOC LONDON 117, 233–72.CrossRefGoogle Scholar
Haimson, B. C. 1977. Crustal stresses in the continental United States as derived from hydrofracturing rocks. In Heacock, J. G. (ed.) The Earth's Crust, 294307. AM GEOPHYS UNION MONOGRA 20.Google Scholar
Harland, W. B. & Bayly, M. B. 1958. Tectonic regimes. GEOL MAG 95, 89104.CrossRefGoogle Scholar
Johnson, M. R. W. & Dalziel, I. W. D. 1966. Metamorphosed lamprophyres and late thermal history of the Moines. GEOL MAG 103, 240–9.CrossRefGoogle Scholar
Johnson, M. R. W., Sanderson, D. J. & Soper, N. J. 1979. Deformation in the Caledonides of England, Ireland and Scotland. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 165–86. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Johnstone, G. S., Smith, D. I. & Harris, A. L. 1969. The Moinian assemblage of Scotland. In Kay, M. (ed.) North Atlantic geology and continental drift, 159–80. MEM AM ASSOC PET GEOL 12.Google Scholar
Johnstone, G. S. 1975. The Moine Succession. In Harris, A. L., Shackelton, R. M., Watson, J., Downie, C., Harland, W.B. & Moorbath, S. (eds) A correlation of Precambrian rocks in the British Isles. SPEC REP GEOL SOC LONDON 6, 3042.Google Scholar
Kaitaro, S. 1953. Geological structure of the late Precambrian intrusives of the Åva area, Ålan Islands. BULL COMM GEOL FINL 162, 479.Google Scholar
Lambert, R. St J. 1969. Isotopie studies relating to the Precambrian history of the Moinian of Scotland. PROC GEOL SOC LONDON 1652, 243–4.Google Scholar
Lambert, R. St J., Winchester, J. A. & Holland, J. G. 1979. Time, space and intensity relationships of the Precambrian and lower Palaeozoic metamorphisms of the Scottish Highlands. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 363–8. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Lawrie, T. R. M. 1961. Scottish Highlands and Islands. SUMM PROGR GEOL SURV LONDON for 1960.Google Scholar
Long, L. E. & Lambert, R. St J. 1963. Rb–Sr isotope ages from the Moine series. In Johnson, M. R. W. & Stewart, F. H. (eds) The British Caledonides, 217–48. Edinburgh: Oliver & Boyd.Google Scholar
Piasecki, M. A. 1980. New light on Moine rocks of the Central Highlands of Scotland. J GEOL SOC LONDON 137, 4159.CrossRefGoogle Scholar
Piasecki, M. A. J. & van Breemen, O. 1979. The ‘Central Highland Granulites’: cover-basement tectonics in the Moine. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 139–44. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Piasecki, M. A. J., van Breemen, O. & Wright, A. E. 1981. Late Precambrian geology of Scotland, England and Wales. In Kerr, J. W. & Fergusson, A. M. (eds) Geology of the North Atlantic Borderlands, 5794. MEM CAN SOC PET GEOL 7.Google Scholar
Pitcher, W. S. & Berger, A. R. 1972. The Geology of Donegal. London: Wiley Interscience.Google Scholar
Powell, D. 1974. Stratigraphy and structure of the western Moine and the problem of Moine orogenesis. J GEOL SOC LONDON 130, 575–93.CrossRefGoogle Scholar
Powell, D., Baird, A. W., Charnley, N. R. & Jordan, P. J. 1981. The metamorphic environment of the Sgurr Beag Slide; a major crustal displacement zone in Proterozoic, Moine rocks of Scotland. J GEOL SOC LONDON 138, 661–73.CrossRefGoogle Scholar
Ramsay, D. M. & Sturt, B. A. 1979. The status of the Banff nappe. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 145–52. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Rathbone, P. A. & Harris, A. L. 1979. Basement–cover relationships at Lewisian inliers in the Moine rocks. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 683–97. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Rast, N. & Platt, J.L. 1957. Cross-folds. GEOL MAG 94, 159–67.Google Scholar
Roberts, J. L. 1970. The intrusion of magma into brittle rocks. In Newall, G. and Rast, N. (eds) Mechanisms of Igneous Intrusion. GEOL J SPEC ISSUE 2, 287338.Google Scholar
Smith, D. I. 1979. Caledonian minor intrusions of the N Highlands of Scotland. In Harris, A. L.et al. (eds) The Caledonides of the British Isles—reviewed, 683–98. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Smith, R. B. 1977. Formation of folds, boudinage, and mullions in non-Newtonian materials. BULL GEOL SOC AM 88, 312–20.Google Scholar
Soper, N. J. & Barber, A. J. 1979. Proterozoic folds on the northwest Caledonian foreland. SCOTT J GEOL 15, 111.CrossRefGoogle Scholar
Strachan, R. A. 1982. Tectonic sliding within the Moinian Loch Eil Division near Kinlocheil, W Inverness-shire. SCOTT J GEOL 18, 187203.CrossRefGoogle Scholar
Talbot, C. J. 1970. The minimum strain ellipsoid using deformed quartz veins. TECTONOPHYSICS 9, 4776.CrossRefGoogle Scholar
Talbot, C. J. 1982. Obliquely foliated dykes as deformed incompetent single layers. BULL GEOL SOC AM 93, 450–60.2.0.CO;2>CrossRefGoogle Scholar
Tanner, P. W. G. 1970. The Sgurr Beag Slide—a major tectonic break within the Moinian of the western Highlands of Scotland. Q J GEOL SOC LONDON 126, 435–63.CrossRefGoogle Scholar
Tobisch, P. T., Fleuty, M. J., Merh, S. S., Muhopadhyayi, D. & Ramsay, J. G. 1970. Preformational and metamorphic history of Moinian and Lewisian rocks between Strathconan and Glen Affric. SCOTT J GEOL 6, 243365.CrossRefGoogle Scholar
van Breemen, O., Pidgeon, R. & Johnson, M. R. W. 1974. Pre-Cambrian and Palaeozoic pegmatites in the Moines of northern Scotland. J GEOL SOC LONDON 130, 493507.CrossRefGoogle Scholar
van Breemen, O., Halliday, A. N., Johnson, M. R. W. & Bowes, D. R. 1978. Crustal additions in late Precambrian times. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 81106. GEOL J SPEC ISSUE 10.Google Scholar
van Breemen, O., Aftalion, M., Pankhurst, R. J. & Richardson, S. W. 1979. Age of the Glen Dessary Syenite, Inverness-shire: diachronous Palaeozoic metamorphism across the Great Glen. SCOTT J GEOL 15, 4962.CrossRefGoogle Scholar
Waterson, J. S. 1968. Plutonic development of the Ilordleq area, South Greenland, Part II: Late kinematic basic dikes. MEDD GRONLAND 185, 1104.Google Scholar