OR/15/053 Provenance of building stones in four 'galley castles' in Argyll Minerals & Waste Programme Commissioned Report OR/15/053 OR/15/053 BRITISH GEOLOGICAL SURVEY MINERALS & WASTE PROGRAMME COMMISSIONED REPORT OR/15/053 Provenance of building stones in four 'galley castles' in Argyll Paul A Everett, Martin R Gillespie and Emily A Tracey The National Grid and other Ordnance Survey data © Crown Copyright and database rights 2015. Ordnance Survey Licence No. 100021290 EUL. Keywords Report; provenance, building stone, decorative stone, dressing stone, medieval, castle, galley castle, Sween, Dunstaffnage, Skipness, Kilchurn, Kisimul, Argyll, Scotland, Historic Scotland. Front cover Castle Sween, Knapdale Bibliographical reference EVERETT, P A, GILLESPIE, M R and Tracey, E A. 2015. Provenance of building stones in four 'galley castles' in Argyll. British Geological Survey Commissioned Report, OR/15/053. 53pp. Copyright in materials derived from the British Geological Survey’s work is owned by the Natural Environment Research Council (NERC) and/or the authority that commissioned the work. You may not copy or adapt this publication without first obtaining permission. Contact the BGS Intellectual Property Rights Section, British Geological Survey, Keyworth, e-mail [email protected]. You may quote extracts of a reasonable length without prior permission, provided a full acknowledgement is given of the source of the extract. Maps and diagrams in this report use topography based on Ordnance Survey mapping. © NERC 2015. All rights reserved Keyworth, Nottingham British Geological Survey 2015 OR/15/053 BRITISH GEOLOGICAL SURVEY The full range of our publications is available from BGS shops at British Geological Survey offices Nottingham, Edinburgh, London and Cardiff (Welsh publications only) see contact details below or shop online at www.geologyshop.com BGS Central Enquiries Desk Tel 0115 936 3143 Fax 0115 936 3276 The London Information Office also maintains a reference collection of BGS publications, including maps, for consultation. email [email protected] We publish an annual catalogue of our maps and other publications; this catalogue is available online or from any of the Environmental Science Centre, Keyworth, Nottingham BGS shops. 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........................................................................................................................................ ii 1 Introduction ............................................................................................................................ 1 2 Geological context .................................................................................................................. 3 2.1 Some terminology and concepts ..................................................................................... 3 2.2 Geological history........................................................................................................... 5 3 Possible sources of decorative stone in Argyll galley castles .............................................. 9 3.1 Metamorphosed rocks..................................................................................................... 9 3.2 Sandstones .................................................................................................................... 11 4 Castle Sween ......................................................................................................................... 16 4.1 Layout and building chronology................................................................................... 16 4.2 Building stones ............................................................................................................. 18 5 Skipness Castle ..................................................................................................................... 20 5.1 Layout and building chronology................................................................................... 20 5.2 Building stones ............................................................................................................. 22 6 Dunstaffnage Castle ............................................................................................................. 25 6.1 Layout and building chronology................................................................................... 25 6.2 Building stones ............................................................................................................. 27 7 Kilchurn Castle ..................................................................................................................... 30 7.1 Layout and building chronology................................................................................... 30 7.2 Building stones ............................................................................................................. 32 8 Kisimul Castle ....................................................................................................................... 34 9 Summary and conclusions ................................................................................................... 35 Appendix 1 Sampling and petrographic descriptions ........................................................ 38 References .................................................................................................................................... 47 i OR/15/053 FIGURES Figure 1 Map of the Argyll coastline and the location of galley castles assessed in this report ..... 2 Figure 2 Geological time chart ........................................................................................................ 4 Figure 3 The major geological terranes and geological faults of Scotland ..................................... 5 Figure 4 Simplified geology map of Argyll, Morvern and Arran ................................................... 8 Figure 5 Locations of quarries in metamafic rock visited during the site visit ............................. 10 Figure 6 Sites of possible sources of sandstone used in Argyll galley castles .............................. 11 Figure 7 BGS samples of sandstone from quarries in Argyll and Arran ...................................... 15 Figure 8 Plans for Castle Sween with periods of construction and alteration.. ............................. 17 Figure 9 Decorative stone in Castle Sween ................................................................................... 19 Figure 10 Plans for Skipness Castle with periods of construction and alteration. ........................ 21 Figure 11 Decorative stones in Skipness Castle ............................................................................ 24 Figure 12 Plans for Dunstaffnage Castle with periods of construction and alteration. ................. 26 Figure 13 Decorative stone in Dunstaffnage Castle ...................................................................... 29 Figure 14 Plans for Kilchurn Castle with periods of construction and alteration. ........................ 31 Figure 15 Decorative stone in Kilchurn Castle ............................................................................. 33 TABLES Table 1 Details of quarries visited during the site visit ................................................................... 9 Table 2 Timeline of construction and alterations in Castle Sween ............................................... 16 Table 3 Timeline of construction and alterations in Skipness Castle ........................................... 20 Table 4 Timeline of construction and alteration in Dunstaffnage Castle ...................................... 25 Table 5 Timeline of construction and alterations in Kilchurn Castle ........................................... 30 Table 6 Summary of building stone provenance in Argyll galley castles ..................................... 37 Summary This report describes the outcomes of a project to assess the character and provenance of decorative stones in four ‘galley castles’ in Argyll. This includes a comparative