Hostname: page-component-76fb5796d-25wd4 Total loading time: 0 Render date: 2024-04-26T02:29:48.767Z Has data issue: false hasContentIssue false

Mesozoic sedimentation and sedimentary rocks in the Inner Hebrides

Published online by Cambridge University Press:  26 July 2012

J. D. Hudson
Affiliation:
Department of Geology, University of Leicester, Leicester LEI 7RH
Get access

Synopsis

In the Inner Hebrides Mesozoic sediments rest unconformably on much older, harder and more deformed rocks: they are overlain by Tertiary lavas and cut by sub-volcanic intrusions. The Triassic rocks are unfossiliferous conglomerates and sandstones, deposited on alluvial fans and river flood plains in a semiarid climate. Active faults controlled sedimentation. In the early Jurassic the sea transgressed across the region; a basin of net sediment accumulation lay between uplifted regions now represented by the Highlands and the Outer Hebrides. The lower and lower-middle Jurassic is composed of marine shalesandstone alternations comparable to those providing the sources and reservoirs for North Sea oil. Ammonites provide good correlation with the European succession. In the Great Estuarine Group, environments ranged from lagoonal to deltaic to dolomitic mud-flat. Molluscan assemblages can be compared to modern brackish-water faunas. In the upper Jurassic there is a return to marine shales and minor sandstones; ammonites help correlation between Europe and the Boreal province. The lower Cretaceous is absent; thin upper Cretaceous rests disconformably on older rocks. The rocks are not metamorphosed except slightly near the Tertiary plutonic centres. Their softness makes them susceptible to erosion, and, especially where shales are overlain by basalts, extensive landslips occur.

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

Each reference to a paper in the symposium carries an asterisk indicating that it is contained in Proc. Roy. Soc. Edinb. 83B.Google Scholar
Amiri-Garoussi, K. 1977. Origin of montmorillionite in early Jurassic shales of NW Scotland. Geol. Mag. 114, 281290.Google Scholar
Anderson, F. W. and Dunham, K. C. 1966. The geology of northern Skye. Mem. Geol. Surv. G.B.Google Scholar
Anderton, R. and Bowes, D. R. 1983. Precambrian and Palaeozoic rocks of the Inner Hebrides. Proc. Roy. Soc. Edinb. 83B, 3145.Google Scholar
Bailey, E. B. et al. 1924. The Tertiary and post-Tertiary geology of Mull, Loch Aline and Oban. Mem. Geol. Surv. Scotl.Google Scholar
Bailey, E. B. Weir, J. 1932. Submarine faulting in Kimmeridgian times in east Sutherland. Trans. Rov. Soc. Edinb. 57, 429467.Google Scholar
Binns, P. E.. McQuillan, R.. Fannin, N. G. T., Kenolty, N. and Ardus, D. A. 1975. Structure and stratigraphy of sedimentary basins in the Sea of the Hebrides and the Minches. In Petroleum and the continental shelf of north wen Europe. I, Geology ed. Woodland, A. W. pp. 93102. Barking, Essex: Applied Science Publishers.Google Scholar
Bradshaw, M. J. and Fenton, J. 1982. The Bajocian ‘Coinbrash’ of Raasay, Inner Hebrides: palynology, facies analysis and a revised geological map. Scott. J. Geol. 18, 131145.Google Scholar
Cope, J. C. W., Duff, K. L., Parsons, C. F., Torrens, H. S., Wimbledon, W. A. and Wright, J. K. 1980. A correlation of Jurassic rocks in the British Isles, Part Two, Middle and Upper Jurassic. Spec. Rep. Geol. Soc. London. 15.Google Scholar
Wright, J. K. Getty, T. A.. Howarth, M. K., Morton, N. and Torrens, H. S. 1980. A correlation of Jurassic rocks in the British Isles. 1. Introduction and Lower Jurassic. Spec. Rep. Geol. Soc. Lond. 14.Google Scholar
Donaldson, C. H., 1983. Tertiary igneous activity in the Inner Hebrides. Proc. Roy. Soc. Edinb. 83B, 6581.Google Scholar
Frazer, F. 1981. The Scotsman, 4 Nov. 1981, p. 9.Google Scholar
George, T. N. 1966. Geomorphic evolution in Hebridean Scotland. Scon. J. Geol. 2, 134.Google Scholar
Gribble, C. D., 1983. Mineral resources of the Inner Hebrides. Proc. Roy. Soc. Edinb. 83B, 611625.Google Scholar
Hallam, A. 1959. Stratigraphy of the Broadford Beds of Skye, Raasay and Applecross. Proc. Yorks. Geol. Soc. 32, 165184.CrossRefGoogle Scholar
Hallam, A. 1965. Jurassic, Cretaceous and Tertiary sediments. In The Geology of Scotland, ed. Craig, G. Y. Ch.-12, pp. 401416. Edinburgh: Oliver & Boyd.Google Scholar
Harris, J. P. and Hudson, J. D. 1980. Lithostratigraphy of the Great Estuarine Group (Middle Jurassic), Inner Hebrides. Scott. J. Geol. 16, 231250.Google Scholar
Howarth, M. K. 1956. The Scalpa Sandstone of the Isle of Raasay, Inner Hebrides. Proc. Yorks. Geol. Soc. 30, 353370, pi. 27.CrossRefGoogle Scholar
Howarth, M. K. 1958. The Ammonites of the Liassic family Amaltheidae in Britain. Palaeontogr. Soc. Monogr.Google Scholar
Howitt, F., Aston, E. R. and Jacque, M. 1975. The occurrence of Jurassic volcanics in the North Sea. In Petroleum geology of the continental shelf of north-west Europe, I, Geology, ed. Woodland, A. W. pp. 379387. Barking, Essex: Applied Science Publishers.Google Scholar
Hudson, J. D. 1962. The stratigraphy of the Great Estuarine Series (Middle Jurassic) of the Inner Hebrides. Trans. Edinb. Geol. Soc. 19, 139165.CrossRefGoogle Scholar
Hudson, J. D. 1964. The petrology of the sandstones of the Great Estuarine Series, and the Jurassic palaeogeography of Scotland. Proc. Geol. Ass. 75, 499527.CrossRefGoogle Scholar
Hudson, J. D. 1968. The microstructure and mineralogy of the shell of a Jurassic mytilid (Bivalvia), Palaenotology 11, 168182.Google Scholar
Hudson, J. D. 1970. Algal limestones with pseudomorphs after gypsum from the Middle Jurassic of Scotland. Scott. J. Geol. 2, 1140.Google Scholar
Hudson, J. D. 1980. Aspects of brackish-water facies and faunas from the Jurassic of north-west Scotland. Proc. Geol. Ass. 91, 99105.CrossRefGoogle Scholar
Hudson, J. D. Harris, J. P. 1979. Sedimentology of the Great Estuarine Group (Middle Jurassic) of North-West Scotland. In Symposium sur las sedimentation du Jurassique W. Europeen (Paris 1977), pp. 113. Paris: Assoication des Sedimentologistes Francais.Google Scholar
Hudson, J. D. and Morton, N. 1969. International Field Symposium on the British Jurassic. Excursion no. 4, Guide for Western Scotland. Keele University.Google Scholar
Humphries, D. W. 1961. The Upper Cretaceous White Sandstone of Loch Aline, Argyll, Scotland. Proc. Yorks. Geol. Soc. 33, 4776.Google Scholar
Institute of Geological Sciences, 1979. Map of sub-Pleistocene geology oj the British Isles and the adjacent continental shelf, 1:2,500,000 (2nd edn).Google Scholar
Jaeger, J. C. 1959. Temperatures outside a cooling intrusive sheet. Am. J. Sci. 257, 4454.Google Scholar
Judd, J. W. 1878. The Secondary Rocks of Scotland. III. The strata of the Western Coast and Islands. Q. Jl. Geol. Soc. Lond. 34, 660743, pl. 1.Google Scholar
Lee, G. W. and Bailey, E. B. 1925. The Pre-Tertiary Geology of Mull, Loch Aline and Oban. Mem. Geol. Surv. Scotl.Google Scholar
McCallum, J. A. A. 1972. Sedimentation of the middle Liassic rocks of the Inner Hebrides, Scotland. Unpubl. Ph.D. Thesis, Univ. of Glasgow.Google Scholar
Miller, H. 1858. The Cruise of the Betsey. Edinburgh.Google Scholar
Morton, N. 1976. Bajocian (Jurassic) stratigraphy in Skye, Western Scotland, Scotland. Scott. J. Geol. 12, 2333.CrossRefGoogle Scholar
Nicholson, R. 1978. The Camas Malag Formation: an interbedded rhythmite/conglomerate sequence of probable Triassic age, Loch Slapin, Isle of Skye. Scott. J. Geol. 14, 301309.Google Scholar
Oates, M. J. 1978. A revised stratigraphy for the western Scottish Lower Lias. Proc. Yorks. Geol. Soc., 42, 143156, pis. 2. 3.CrossRefGoogle Scholar
Peacock, J. D. 1983. Quaternary geology of the Inner Hebrides. Proc. Roy. Soc. Edinb. 83B, 8389.Google Scholar
Penn, I. E. and Merriman, R. J. 1978. Jurassic (Toarcian to ?Bajocian) ammonites of the Shiant Isles, Outer Hebrides. Scott. J. Geol. 14, 4553, pi. 1.Google Scholar
Rawson, P. F. et al. 1978. A correlation of the Cretaceous rocks of the British Isles. Spec. Rep. Geol. Soc. Lond. 9.Google Scholar
Richey, J. E. and Thomas, H. H. 1930. The geology of Ardnamurchan, north-west Mull and Coll. Mem. Geol. Surv. G.B.Google Scholar
Riley, L. A. 1980. Palynological evidence of an early Portlandian age for the uppermost Helmsdale Boulder Beds. Sutherland. Scott. J. Geol. 16, 2931.Google Scholar
Scoffin, T. P. 1973. Crustacean faecal pellets, Favreina, from the Middle Jurassic of Eigg, Inner Hebrides. Scott. J. Geol. 9, 145146.Google Scholar
Sellwood, B. W. 1972. Regional environmental changes across a Lower Jurassic stage boundary in Britain. Palaeontology 15, 125157.Google Scholar
Smythe, D. K., Sowerbutts, W. T. C., Bacon, M. and McQuillan, R. 1971. Deep sedimentary basin belownorthern Skye and the Little Minch. Nature Phys. Sci. 236, 8789.CrossRefGoogle Scholar
Steel, R. J., 1971. New Red Sandstone movement on the Minch Fault. Nature Phys. Sci. 234, 158159.Google Scholar
Steel, R. J., 1977. Triassic rift basins of north-west Scotland—their configuration, infilling and development. MNNSS-7. In Proceedings: Mesozoic Northern North Sea Symposium, Oslo 1977, ed. Finstad, K. G. and Selby, R. C. Oslo: Norsk Petroleum Forening.Google Scholar
Surlyk, F. 1977. Mesozoic faulting in East Greenland. Geologie Mijnb. 56, 311327.Google Scholar
Sykes, R. M. 1975a. The stratigraphy of the Callovian-Oxfordian stages (Middleupper Jurassic) in Northern Scotland. Scott. J. Geol. 11, 5178.Google Scholar
Sykes, R. M. 1975b. Fades and fauna! analysis of the Callovian and Oxfordian stages (Middle-Upper Jurassic) in Northern Scotland and East Greenland. Unpubl. D. Phil. Thesis, Univ. of Oxford.Google Scholar
Sykes, R. M. Callomon, J. H. 1979. The Ameoboceras zonation of the Boreal Upper Oxfordian. Palaeontology 22, 839903.Google Scholar
Tan, F. C. and Hudson, J. D. 1971. Carbon and oxygen isotopic relationships of dolomites and coexisting calcites. Great Estuarine Series (Jurassic) of Scotland. Geochim. Cosmochim. Ada 35, 755767.Google Scholar
Tan, F. C. and Hudson, J. D. 1974. Isotopic studies on the palaeocology and diagenesis of the Great Estuarine Series (Jurassic) of Scotland. Scott. J. Geol. 10, 91128.Google Scholar
Taylor, H. P. Jr. and Forester, R. W. 1971. Low-O18 igneous rocks from the intrusive complexes of Skye, Mull and Ardnamurchan, western Scotland. J. Petrology 12, 465497.Google Scholar
Turner, J. 1966. The Oxford Clay of Skye, Scalpay and Eigg. Scott. J. Geol. 2, 243252.Google Scholar
Van Hinte, J. E. 1976. A Jurassic time-scale. Bull. Am. Ass. Petrol. Geol. 60, 489497.Google Scholar
Waldman, M. and Savage, R. J. G. 1972. The first Jurassic mammal from Scotland. J. Geol. Soc. Lond. 128, 119125.Google Scholar
Walker, G. P. L., 1971. The distribution of amygdale minerals in Mull and Morvern (Western Scotland). In West Commemoration Volume, Studies in Earth Sciences ed. Murty, T. V. V. G. R. K. and Rao, S. S., pp. 181194. New Dehli: Today and Tomorrows Printers.Google Scholar
Warrington, G. et al. 1980. A correlation of the Triassic rocks in the British Isles. Spec. Rep. Geol. Soc. Lond. 13.Google Scholar
Wright, J. K. 1973. Middle and Upper Oxfordian and Kimmeridgian Staffin Shales, at Staffin, Isle of Skye. Proc. Geol. Asso. 84, 447457.CrossRefGoogle Scholar