Permian, Triassic and Jurassic: deserts, rivers and shallow seas, introduction, Northern England

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From: Stone, P, Millward, D, Young, B, Merritt, J W, Clarke, S M, McCormac, M and Lawrence, D J D. 2010. British regional geology: Northern England. Fifth edition. Keyworth, Nottingham: British Geological Survey.


Introduction

Series of palaeogeographical reconstructions showing continental movements from the Ordovician to the Palaeogene (after Woodcock and Strachan, 2000). P916033.

The major continental collision that drove the Variscan Orogeny during late Carboniferous and early Permian times created the Pangaean supercontinent. Within this landmass, Britain lay in a tropical latitude, approximately 10° north of the equator, and drifted slowly northwards to subtropical latitudes of approximately 30° north by early Triassic times (P916033)d. The depositional environments included widespread deserts, tropical and evaporitic seas, fluvial outwash plains, ephemeral lakes and mudflats.

Erosion of the folded and uplifted Carboniferous strata had generated mature, gently rolling plains across which spread an early Permian desert. By late Permian times, continental extension had opened seaways, flooding low ground across large inland drainage basins. On the western edge of northern England, the Bakevellia Sea developed, covering approximately the area of the present-day Irish Sea and its marginal areas. To the east, the Zechstein Sea covered approximately the area of the present-day North Sea and extended as far to the east as Lithuania and Poland. Early Triassic times saw continental deposition restored over northern England. Large river systems transported sands from the south and aeolian dune fields developed. Further marine transgression in mid to late Triassic times, the result of expansion of the Tethys Ocean from southern Europe, then brought coastal conditions to northern England; open marine conditions followed in Jurassic times.

Today, Permian strata are preserved in northern England to the north-west of the Pennines, around Carlisle, in the Vale of Eden and in west Cumbria, and to the east of the Pennines, over much of County Durham. Permian strata also occur at the north-east end of the Isle of Man but are there entirely obscured by thick superficial deposits. Triassic strata have a similar though more restricted onshore outcrop. In northern England, Jurassic strata are only known from the vicinity of Carlisle; those that succeed the Triassic succession near Middlesbrough fall into another regional district — that of East Yorkshire and Lincolnshire. It is probable that Permian and Triassic rocks once partially covered the Carboniferous strata of the north Pennines, northern Cumbria and Northumberland, and that Jurassic rocks also had a much wider original distribution.

Bibliography

Barnes, R P, Ambrose, K, Holliday, D W, and Jones, N S. 1994. Lithostratigraphical subdivision of the Triassic Sherwood Sandstone Group in west Cumbria. Proceedings of the Yorkshire Geological Society, Vol. 50, 51–60.

Benton, M J, Cook, E, and Turner, P. 2002. Permian and Triassic red beds and the Penarth Group of Great Britain. Geological Conservation Review, No. 24. (Peterborough: Joint Nature Conservation Committee.)

Brookfield, M E. 2004. The enigma of fine-grained alluvial basin fills: the Permo-Triassic (Cumbrian Coastal and Sherwood Sandstone Groups) of the Solway Basin, NW England and SW Scotland. International Journal of Earth Sciences, Vol. 93, 282–296.

Holliday, D W, Holloway, S, McMillan, A A, Jones, N S, Warrington, G, and Akhurst, M C. 2004. The evolution of the Carlisle Basin, NW England and SW Scotland. Proceedings of the Yorkshire Geological Society, Vol. 55, 1–19.

Holliday, D W, Jones, N J, and McMillan, A A. 2008. Lithostratigraphical subdivision of the Sherwood Sandstone Group (Triassic) of the north-eastern part of the Carlisle Basin, Cumbria and Dumfries and Galloway, UK. Scottish Journal of Geology, Vol. 44, 97–110.

Ivimey-Cook, H C, Warrington, G, Worley, N E, Holloway, S, and Young, B. 1995. Rocks of Late Triassic and Early Jurassic age in the Carlisle basin Cumbria (north-west England). Proceedings of the Yorkshire Geological Society, Vol. 50, 305–316.

Jackson, D I, and Johnson, H. 1996. Lithostratigraphic nomenclature of the Triassic, Permian and Carboniferous of the UK offshore East Irish Sea Basin. (Nottingham: British Geological Survey for the United Kingdom Offshore Operators Association.)

Jones, N S, and Ambrose, K. 1994. Triassic sandy braidplain and aeolian sedimentation in the Sherwood Sandstone Group of the Sellafield area, west Cumbria. Proceedings of the Yorkshire Geological Society, Vol. 50, 61–76.

Smith, D B. 1989. The late Permian palaeogeography of north-east England. Proceedings of the Yorkshire Geological Society, Vol. 47, 285–312.

Smith, D B. 1995. Marine Permian of England. Geological Conservation Review, No. 8. (Peterborough: Joint Nature Conservation Committee.)

Tucker, M E. 1991. Sequence stratigraphy of carbonate–evaporite basins; models and applications to the Upper Permian (Zechstein) of northeast England and adjoining North Sea. Journal of the Geological Society of London, Vol. 148, 1019–1036.

Worley, N E. 2005. The occurrence of halite in the Permian A Bed Evaporite, Kirkby Thore, Cumbria. Proceedings of the Yorkshire Geological Society, Vol. 55, 199–203.