The Building Stones of Cornwall, This Report Would Not Have Been Possible
Total Page:16
File Type:pdf, Size:1020Kb
The Identification of Heritage Quarries Minerals Safeguarding DPD Evidence Report December 2018 Contents 1 Executive summary ............................................................................ 11 2 Part 1: Overview and Geology .............................................................. 12 2.1 Background ................................................................................. 12 2.2 Review of earlier research and publications ..................................... 12 2.3 Conservation and abandoned pits and quarries ................................ 13 2.4 Methodology ............................................................................... 15 2.5 Study Findings ............................................................................. 16 2.6 The Geological Background to Cornish Building Materials .................. 20 2.7 Types of Extractive Activity ........................................................... 24 2.8 Building Stones that Have Been Worked in Cornwall ......................... 25 2.8.1 Granitic rocks ........................................................................ 26 2.8.2 Elvans .................................................................................. 29 2.8.3 Greenstones .......................................................................... 34 2.8.4 Slates ................................................................................... 36 2.8.5 Sandstones ........................................................................... 37 2.8.6 Other stones ......................................................................... 39 3 Part 2: Building Stones of Cornwall ....................................................... 42 3.1 Heritage Quarry Assessments ........................................................ 42 3.2 Elvans and Flows ......................................................................... 43 3.2.1 Pentewan Quarries (Elvan1) .................................................... 43 3.2.2 Newham Quarry (Elvan2) ........................................................ 49 3.2.3 Tremore quarries (Elvan3) ...................................................... 52 3.2.4 Treveddoe Quarries (Elvan 4) .................................................. 57 3.2.5 Brannel Quarry (Elvan5) ......................................................... 59 3.2.6 Polgooth, Treloweth and Hewaswater Quarries (Elvan6).............. 61 3.2.7 Penrice Woods Quarry (Elvan7) ............................................... 63 3.2.8 Quarries at Castle Gotha Crossroads (Elvan8) ........................... 65 3.2.9 St Kew Quarry (Elvan9) .......................................................... 67 3.2.10 Watergate Quarry (Elvan10) ................................................... 69 3.3 Granites ..................................................................................... 71 3.3.1 Bodmin Moor Granite Quarries (De Lank and Hantergantick (Granite1) ......................................................................................... 71 3.3.2 Carnmenellis Granite Quarries (Granite2) ................................. 75 3.3.3 All Granite 2 .......................................................................... 80 The Identification of Heritage Quarries Minerals Safeguarding DPD Evidence Report 2 Adoption December 2018 3.3.4 Luxulyan Area Granite Quarries (Granite3) ................................ 82 3.3.5 All Granite 3 .......................................................................... 84 3.3.6 Carn Grey Quarry (Granite4) ................................................... 88 3.3.7 Nanpean, St Stephen and St Dennis area Quarries (Granite5) ..... 91 3.3.8 Kit Hill Quarry (Granite6) ........................................................ 95 3.3.9 Hingston Down Quarries (Granite7) .......................................... 97 3.3.10 South East Bodmin Moor Quarries (Granite8) ............................ 99 3.3.11 Tregoning Hill Granite Quarries: Tolmennor and Gluyas (Granite9) 103 3.3.12 Lands End Granite Quarries (Granite10) ................................. 105 3.4 Greenstones .............................................................................. 111 3.4.1 Cataclews Quarry (Greenstones1) .......................................... 111 3.4.2 Polyphant Quarry (Greenstones2) .......................................... 115 3.4.3 Duporth (Greenstones3) ....................................................... 119 3.4.4 Tregongeeves Quarry (Greenstones4) .................................... 121 3.4.5 Molingey Quarry (Greenstones5) ........................................... 123 3.4.6 Tubbs Mill Quarry (Greenstones6) .......................................... 124 3.4.7 Lean Quarry (Greenstones7) ................................................. 125 3.4.8 Tintagel Greenstones (Greenstones8) ..................................... 127 3.4.9 Greystone Quarry (Greenstones9).......................................... 129 3.4.10 Blackhill Quarry (Greenstones10) ........................................... 131 3.4.11 West of England (Porthoustock) Quarry (Greenstones11) .......... 133 3.4.12 Dean Quarry (Greenstones12) ............................................... 135 3.4.13 Serpentine Quarries (including Gwendreath) (Greenstones13) ... 137 3.4.14 Countybridge and Trevassack Quarries (Greenstones14)........... 142 3.5 Sandstones ............................................................................... 144 3.5.1 Pigsdon, Cansford and Herdbury Quarries (Sandstone1) ........... 144 3.5.2 Tredinnick Quarry (Grampound) (Sandstone2) ........................ 150 3.5.3 Sandrock – no specific quarry (Sandstone3) ............................ 153 3.6 Slates ....................................................................................... 156 3.6.1 Delabole Quarry (Slate1) ...................................................... 156 3.6.2 Tintagel Slate Quarries (Slate 2) ............................................ 159 3.6.3 St Issey Slate Quarries (Slate3) ............................................. 166 3.6.4 Callywith Quarry (Slate4)...................................................... 170 3.6.5 South East Cornwall Slate Quarries (Slate5) ............................ 172 3.6.6 Miscellaneous sources of slate (Slate 6) .................................. 176 3.7 Miscellaneous Sources of Stone ................................................... 184 The Identification of Heritage Quarries Minerals Safeguarding DPD Evidence Report 3 Adoption December 2018 3.7.1 Pilsamoor Quarry (Chert1) .................................................... 184 3.8 Notes on further building stones .................................................. 186 3.8.1 Calc-flintas. ......................................................................... 186 3.8.2 Schorl rock and related types ................................................ 187 3.8.3 Topazfels ............................................................................ 188 3.8.4 Quartz ................................................................................ 188 3.8.5 Moorstone ........................................................................... 188 3.8.6 Serpentine ‘moorstone’ ......................................................... 189 3.8.7 Minestone ........................................................................... 189 4 Bibliography .................................................................................... 190 List of Figures Figure 1 Georgian Penrice House, near St Austell, built from an elvan similar to (but not the same as) Pentewan Stone ....................................................... 14 Figure 2 The south porch of St Mary Magdalen Church, Launceston, built entirely of granite in 1511 .................................................................................... 25 Figure 3 The granite war memorial in the centre of Launceston, erected in 1921 ............................................................................................................. 27 Figure 4 Antony House near Torpoint, built in 1721 ...................................... 30 Figure 5 The remaining gate to the town of Launceston, of late medieval origin34 Figure 6 The Coinage Hall in Truro, largely constructed from a local silty fine- grained sandstone belonging to the Devonian Portscatho Formation ............... 38 Figure 7 Mount Edgecumbe House, southeast Cornwall, originally built in the 1550s, but burnt out during the Second World War and subsequently rebuilt after the war ........................................................................................... 39 Figure 8 Map of Pentewan Quarries (Elvan1) ............................................... 43 Figure 9 Quarry 1 at Pentewan, looking along the excavation south-eastwards towards the sea ....................................................................................... 44 Figure 10 Quarry 2 at Pentewan, looking up the excavation from near the bottom ................................................................................................... 44 Figure 11 Antony House near Torpoint, built in 1721 .................................... 46 Figure 12 The ‘Sermon in Stone’ on the west side of the tower of Holy Trinity, St Austell, entirely carved in the late 15th century from Pentewan Stone ............ 46 Figure 13 Window tracery carved from Pentewan Stone in the 19th century extension to the Chapel at Trelowarren ....................................................... 47 Figure 14 Close-up of the Pentewan Stone used in the 19th century