During the Palaeogene, the NW European continental margin was the site of intense volcanic activity in response to lithospheric thinning and, ultimately, at c. 55 Ma, the formation of a new ocean crust (e.g. White 1988, 1992; Saunders et al. 1997) (Fig. 14.1). Along the west coast of Scotland, vestiges of this period of magmatism take the form of continental (flood) lava sequences, together with shallow intrusive centres and associated lava shields, dyke swarms and sill complexes (Emeleus & Bell 2003). The igneous activity spanned the interval c. 60.5 Ma to 55 Ma and appears to have been intermittent, with significant hiatuses between periods of rapid growth of the lava fields and intrusive activity (Bell & Jolley 1997).
The magmatism is attributed to the impact of the protoIceland plume at the base of the lithosphere, which produced approximately contemporaneous volcanic and intrusive activity between NW Europe and Arctic Canada. The siting of the lava fields was largely controlled by crustal thinning events in the Mesozoic (Thompson & Gibson 1991), whereas the location of the central complexes was strongly influenced by considerably older lineaments. Subsequently, ocean floor spreading took place between NW Europe and East Greenland and between central West Greenland and Baffin Island. The magmas that were erupted or emplaced at the time of continental breakup were not typical of plumes sourced from deep levels in the mantle, and involved much MORB-like material, derived from the upper (depleted) mantle (Saunders et al. 1997). The rate of melt production
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This 4th edition of The Geology of Scotland is edited by Dr Nigel Trewin of the Department of Geology and Petroleum Geology at the University of Aberdeen. The volume is greatly expanded from the previous edition with 34 authors contributing to 20 chapters.
A new format has been adopted to provide a different perspective on the geology of Scotland. A brief Introduction is followed by a chapter outlining some of the important historical aspects that in the 19th century placed Scottish geologists at the forefront of a new science.
Scotland is constructed from a number of terranes that finally combined in roughly their present positions prior to about 410 million years ago. Thus the geology of each terrane is described up to the time of amalgamation, providing chapters on the Southern Uplands, Midland Valley, Northern Highland, Grampian and Hebridean terranes. At the end of this section, a brief synthesis summarizes the events that resulted in the amalgamation of the various terranes into the present configuration.
Traditional practice is followed in the description of the Old Red Sandstone, Carboniferous, Permo-Trias, Jurassic, Cretaceous, Tertiary and Quaternary strata. A separate chapter covers Tertiary igneous rocks. An attempt is made to tell the story of the geological evolution of Scotland, rather than catalogue all areas and formations. Priority is given to the onshore geology, encouraging the reader to go into the field and visit some of the world-class geology on show in Scotland. The chapters are broadly-based, attempting to integrate the sedimentary and igneous histories, and summarize changes in palaeogeography and palaeoenvironments.
Economic aspects are covered with chapters on Metalliferous Minerals, Bulk Resources, Coal and Hydrocarbons. A new departure is a chapter on aspects of Environmental Geology and sustainability.
Additionally, this publication contains a colour section of 32 plates, illustrating aspects of Scottish Geology, as well as a coloured geological map of Scotland.