1 1 2 3 Article-type: Article 4 5 6 The Neoproterozoic to Mid-Devonian evolution of Scotland: a review and 7 unresolved issues. 8 9 John F. Dewey1*, Ian W. D. Dalziel2, R. John Reavy3, and Rob A. Strachan4 10 11 1 University College, High Street, Oxford OX1 4BH, UK 12 2 Institute for Geophysics, Jackson School of Geosciences, The University of Texas at Austin, 13 Austin TX 78758, USA 14 3 School of Biological, Earth, and Environmental Sciences, University College Cork, Cork, 15 Ireland 16 4 School of Environmental Sciences, University of Portsmouth, Portsmouth, UK 17 18 *Correspondence (
[email protected]) 19 20 r/head: Tectonic evolution of Scottish Caledonides 21 22 Abstract: The purpose of this review paper is to identify and outline some critical questions 23 about the geology and tectonic evolution of the Scottish Caledonides in their wider 24 Caledonian/Appalachian context. We outline what we think we know and what we perceive to be 25 some important problems from about 1. 0 Ga (Grenville Orogeny) to Middle Devonian (Acadian 26 Orogeny). We do not attempt in-depth analyses of any terrain or tectonic topic in this review but, 27 mainly, pose questions. Scotland is considered in the context of the Irish Caledonides and the 28 Northern Appalachians, especially Newfoundland, so we make reference to these areas where 29 appropriate. Each section is intended as “stand-alone”, not dependent upon prior or subsequent 30 sections; the sequence of sections, roughly in time order, has a historical narrative thread. We 31 have not included cross-sectional cartoons because we do not have a clear picture of plate 2 32 boundary zone and terrane arrangements in the Caledonides.