 | | Journal (article/letter/editorial) | | 305 The adinoles of Dinas Head, Cornwall. (With Plate XI.) By S. O. AGRELL, B.A., F.G.S. Department...305 I. INTRODUCTION. INAS Head is a small promontory adjoining Trevose Head, some five miles west of Padstow...Padstow on the north coast of Cornwall. Petrographical attention was first drawn to it by Howard Fox...thickness of adinole at Dinas Head. . , / FIG. 1. Geological sketch-map of the St. Mabyn syncline, based...GEOLO(~ICALRELATIONS. Dinas Head is situated at the seaward end of the south limb of the St. Mabyn syncline |  | | Book | | Endsleigh House 50 Daniell Road Truro, Cornwall TR1 2DA England Printed in Great Britain by Short Run...that he knew of no place on earth that surpassed Cornwall in the number and variety of its minerals. Hogg's...is subtitled 'in wich [sic] is shown how much Cornwall contributes to the illustration of the science'...later by Collins' A Handbook to the Mineralogy of Cornwall and Devon' (1871; 1892 with addenda, the latter...mention Purser's 'Minerals and locations in S.W. England' (1974). The work was never published, although |  | | Journal (issue) | | PRICE: 7/6 CONFERENCE OF THE USSHER SOCIETY HELD AT ST. AUSTELL, 1965 Hospitality was offered to the conference...quarry floors. There was a half-day excursion to the St. Austell coastal exposures led by Mr. M. C. McKeown...kaolinite formation in Gwavas quarry, Newlyn, Cornwall.” 75. *Mr. G. M. Power : “The spectrographic analysis...analysis of small quantities of tourmaline from S.W. England ; a preliminary report.” 76. *Dr. C. S. Exley :...North Cornwall.” 87. *Dr. M. J. Ripley : “Structural studies between Holywell Bay and Dinas Head, North |  | | Journal (article/letter/editorial) | | neighbouring quartz grains. These probably represent tridymite that has subsequently inverted back to quartz...quartz, and are similar to the inverted tridymite fringes described and figured by Wyllie (1961, p. 16, and...gives a bibliography of other occurrences of tridymite in fused siliceous rocks. Another type of microlite...Can contents 4-86 % and 1-48 % respectively. Dinas Head (Agrell, 1939) Black carbonaceous slate (anal...here. I t may be remarked that the presence of tridymite fringes round quartz grains in the buchites close |  | | Book | | PO Box 315. Harpenden. Hertfordshire AL5 2ZD. England Telephone: +44 (0)1582 762413 Fax: +44 (0)870 055...the production of e0pper. the mining areas of Cornwall and Devon became important producers of b th tin... I made it a stipulation that e:ich en~ in rn:, ·st ,, ,u.d be fully referenced. After eight years the...for obscure references, and for support from my head of department and secretary. In all cases, help...Oxford University Museum of Natural History; Royal Cornwall Museum, Truro; Sedgwick Museum, University of |  | | Journal (issue) | | ....... 341 Triassic evaporites in south-west England (Abstract). By G. Warrington.................................. 373 Aspects of the hydrogeology of St. Mary's, Scilly Isles. By W. G. Burgess, U. R. Clowes... Supra-batholithic volcanism of the south-west England granites. By M. E. Cosgrove and M. H. Elliott……………………………...geochemical data on rocks from the Lizard complex Cornwall. By P. A. Floyd………………………………………... 402 A preliminary...Preliminary isotopic age determinations from the St. Just mining district (Abstract). By A. N. Halliday |  | | Book (volume) | | BARIUM FELSPARS.166 SILICA MINERALS.179 Quartz, Tridymite, Cristobalite . . . . .179 NEPHELINE GROUP...after a locality on the coast of Labrador (Isle of St. Paul), likewise bytownite derived its name from...Microcline microperthite, type-specimen of charnockite, St. Thomas’ Mount, Madras, India (Howie, 1955). Anal...France (Zaniewska-Chlipalaka, 1937). 2. Adularia, St. Gotthard, Switzerland (Byelyankin, 1915). 3. Adularia...of large crystal (about 3 in. diam.) of adularia, St. Gotthard, Switzerland (Spencer, 1937). Anal. E. |  | | Book (edition) | | Kirby, Wirral, UK Printed by Berforts Information Press, Stevenage, Hertfordshire, UK Downloaded from...Plagioclase feldspars Silica minerals Quartz, Tridymite, Cristobalite Feldspathoids Nepheline and Kalsilite...tabulated data and optical orientation sketches at the head of each mineral section are now accompanied by a...tabulated data and optic orientation sketches at the head of each mineral section, and by including the paragraphs...Tephroite, Benallt Mine, Caernarvonshire, Wales, UK (Smith, W.C. et al., 1944, Mineral. Mag., 27, 3346) |  | | Book (edition) | | Barium feldspars ivelstans hyalophane) Quartz, tridymite, cristobalite NEPHELINE SODALITE illite, pekalsilite...tabulated data and optic orientation sketches at the head of each mineral section, and by including the paragraphs...Fig. 1. Olivine structure parallel to (100) plane. St atoms are at the centres of the tetrahedra and are...occur in the FeO-SiO, system and fayalite and tridymite form a eutectic at 1178°C. Fayalite melts incongruently... Ortho- and Ring Silicates 40 err ae ea a ee opm nr st es ee ages the early stages of such metamorphism |  | | Book | | muscovite-biotite alkali granites among the granites of New England, associated with biotite granites and muscovite...provided by the Armorican intrusions of Devon and Cornwall (15). All are composite, with two or more important...biotite granites, and the granites of Devon and Cornwall may be considered in this connection. With boron...22. A. Tourmalinised granite, Trevalgan, St. Ives, Cornwall. Most of the granite has been replaced by...represent original material. B. Greisen, Cligga Head, Cornwall. Quartz, pale mica, topaz, and tourmaline (both |  | | Book | | Longman Group UK Limited, Longman House, Burnt Mill, Harlow, Essex CM20 2JE, England and Associated...Third Avenue, New York, NY 10158 © Longman Group UK Limited 1987 All rights reserved; no part of this...present day Peridotite-mylonites are exposed on St Paul’s Rocks, which are on the mid-Atlantic ridge...present day Ascension: Azores: Fernando de Noronha: St Helena: Trinidade: Tristan da Cunha: Gough: Reunion:...eruption of Mont Pelee and the 1980 eruption of Mount St Helens. Domes of alkaline composition are well represented |  | | Book (volume) | | crystallize, and fayalite forms a eutectic with tridymite at 1178°C. and withwustite at 1177°C., fayalite...and trachytes. The composition of the fayalite-tridymite-albite eutectic (980°C.) approximates to the composition...composition and is in equilibrium with hedenbergite and tridymite. In the binary system Ca2Si04-Fe2Si04, fayalite...Fe2Si04; it forms a ternary eutectic at 1083°C. with tridymite and iron-cordierite, and has a second ternary...forsterite porphryoblasts from the dunite mylonites of St. Paul s Rocks, in which the (010) plane of the olivines |  | | Book (volume) | | Illite, St. Austell, Cornwall (Levinson, 1955). Anal. English Clays, Lovering Pochin & Co., Ltd., St. Austell...Morar, Inverness-shire (Lambert, 1959). Anal. R. St J. Lambert (Ga 25, Cr 30, V 85, Li 30, Ni 15, Co...Morar, Inverness-shire (Lambert, 1959). Anal. R. St J. Lambert (Ga 22, Cr 50, V 100, Li 40, Sc 10, Sr...Sheet Silicates muscovite-rich granites of New England the greatest amount of muscovite present with plagioclase...and Leinster granites. The greisenization of the St. Austell granite has been described by Exley (1958) |  | | Book | | perature polymorphs, e.g. low quartz, high quartz, tridymite and cristobalite. Such transformations are divided...Reconstructive (1) change in bond angle quartz-tridymite-cristobalite (2) change in structure (symmetry...are rather insensitive to pressure, e.g. quartz-tridymite-cristobalite; ortho¬ clase-microcline; cordierite-indialite...uncommon, e.g. the perfect spherulitic adinole of Dinas Head (Harker, 1939, Fig. 56c) but a bow-tie, fascicular...groups and the presence of surface imperfections (Head, 1962; Fukuta and Mason, 1963). The mismatch between |  | | Book | | SOPER,N. J. Deformation in the Caledonides of England, Ireland and Scotland 165 COWARD, M. P. • SIDDANS...mineralogical evolution of migmatites LAMBERT, R. ST J., WINCHESTER, J. A. & HOLLAND,J. G. Time, space...C-Sil ors S.U.F ;arboniferaus Carboniferous England 2 ~ ~ ~ Limit of Caledonian / Deformation ...INGHAM, J. K. 1970. Distribution of the Toquima-Table Head (Middle Ordovician Whiterock) faunal realm in the...The Cambrian of Wales and 18 R. Nicholson England. In HOLLAND, C. H. (ed.) Cambrian o f the British |  | | Book (volume) | | varlamoffite (partially hydrated stannic oxide) in Cornwall. Min. Mag., vol. 29, p. 817. Scrivenor, J. B....52. Meixner, H., 1942. Eine Korundlagerstatte bei St. Jakob (Oststeirmark). Zentral- blatt Min., Abt...Florida and India, and on a minor scale at Menaccan, Cornwall (menaccanite). The west coast of the South Island...igneous rocks The name is after Count L. A. Perovski of St. Petersburg (Leningrad). The cerian variety, knopite...\o-193 / — . 0-079. J.0-220 0-108. 1 Perovskite St Ambrogio, Piedmont, Italy (Boeris, 1900). 2 Cerian |
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