 | | Journal (article/letter/editorial) | | prehnite-pumpellyite facies assemblages in the Tal y Fan metabasite intrusion, North Wales: implications for Caledonian...BEVINS, Department of Geology, National Museum of Wales, Cardiff CFI 3NP, U.K. R. J . MERRIMAN. British...Keyworth, Nottingham, NG12 SGG, U.K. Abstract. The Tal y Fan Intrusion is a 110 m thick sub-concordant metabasite...and pyroclastic rocks of Ordovician age in North Wales. Despite low grade metamorphism, primary textural...prehnite-pumpellyite facies; Wales, U.K. INTRODUCTION The Lower Palaeozoic rocks of Wales and the Welsh Borderland |  | | Journal (article/letter/editorial) | | Petrological and Geochemical Variations within the Tal y Fan Intrusion: a Study of Element Mobility During...U.K. Department of Geology, National Museum of Wales, Cardiff CF1 3NP, U.K. 2 (Received 1 October 1985;...typescript accepted 7 July 1986) ABSTRACT The Tal y Fan Intrusion is an altered olivine dolerite sheet...rocks of Caradoc (Ordovician) age in NE Snowdonia, Wales. Primary mineral and chemical variations across...Th, in addition to the incompatible elements Zr, Y, Ti, P, Nb, Ta, Hf, and the REE, was immobile even |  | | Report (issue) | | Ordovician Llewelyn Volcanic Group, Snowdonia, North Wales .. I Research Report SG/89/1 Mineralogy and Petrology...Ordovician Llewelyn Volcanic Group, Snowdonia, North Wales T K Ball and R J Merriman BRITISH GEOLOGICAL SURVEY...North Wales T K Ball and R J Merriman Cover illustration Autobrecciated rhyolite of the Conwy Rhyolite...BGS, Keyworth Geographical index United Kingdom, Wales, Snowdonia Subject index Ordovician, petrology,...Ordovician Llewelyn Volcanic Group, Snowdonia, North Wales. British Geowgical Survey Research Report, SG/89/1 |  | | Book | | BASIN VOLC DOC) MARGINAL SM IN SNO (NORTH-WEST WALES) ONIA .. .. • • Front co11er Tryfan, viewed...marginal basin volcanism in Snowdonia (north-west Wales). (London : HMSO for the British Geological Survey...based on Ordnance Survey mapping. Printed in the UK for HMSO Dd 291125 ClO W91 ... lU CONTENTS ...1st Eruptive Cycle 15 llewelyn Volcanic Group 15 Conwy Rhyolite Formation 17 Foel Fras Volcanic Complex...Late acidic volcanism 114 Basic Volcanism: ·yal y Fan and Dolgarrog Volcanic formations 120 s·ubvolcanic |  | THORPE, R. S., LEAT, P. T., MANN, A. C., HOWELLS, M. F., REEDMAN, A. J., CAMPBELL, S. D. G. (1993) Magmatic Evolution of the Ordovician Snowdon Volcanic Centre, North Wales (UK) Journal of Petrology, 34 (4) 711-741 doi:10.1093/petrology/34.4.711 | Journal (article/letter/editorial) | | the Ordovician Snowdon Volcanic Centre, North Wales (UK) by R. S. THORPE 1 *, P. T. LEAT 2 , A. C. MANN...A A, UK 2 Department of Geological Sciences, Science Laboratories, South Road, Durham DH1 3LE, UK 3 Church...4RR, UK 4 British Geological Survey, Bryn Eithyn Hall, Llanfarian, Aberystwyth, Dyfed SY23 4BY, UK (Received...Ordovician Snowdon Volcanic Centre (SVC) of North Wales comprises a bimodal basalt-subalkaline/peralkaline...of cessation of Caledonian subduction in North Wales. Rhyolite magma chambers were short lived and discontinuous; |  | | Journal (article/letter/editorial) | | complex, Sudetes, Poland R . KRYZA A N D A. M U S Z Y N S K I University of Wroclaw, Institute of Geological...opaques and, occasionally, biotite, phengite and stilpnomelane. The sadic amphiboles are glaucophane to crossite...described by Furnes. & Musynski (1984). and Kryza & M u s y w k i (1988). Here we concentrate on the textural...comprises several tectonic 345 346 R . K R Y Z A , A . M U S Z Y N S K I & D. VIELZEUF Melasediments Metabasrtr...1) are believed to be Ordovician in age ( T e i d y r e , 1%3, 1967). They are a monotonous sequence of |  | | Journal (article/letter/editorial) | | minerals (amphibole, biotite, chlorite, epidote, stilpnomelane, titanite, apatite, and quartz) in variable...Clinopyroxene Chlorite Biotite Ca-amphibole Stilpnomelane Calcite Epidote Ilmenite Titanite Apatite 45...plagioclase, chlorite, biotite, amphibole, stilpnomelane, epidote and Ti-minerals in the Nurra metagabbro...Al/(Al þ Mg þ Fe) ratio of chlorite is 0.35. Stilpnomelane occurs as small elongated grains (<0.1 mm in...0.61 1.32 2.56 100.00 V Cr Co Ni Cu Zn Ga Rb Sr Y Zr Nb Cs Ba Hf Ta Th U 215 55.2 25.5 10 10 45 21 |  | | Journal (article/letter/editorial) | | phengite, epidote, clinozoisite, chlorite, garnet, stilpnomelane, piedmontite, albite, titanite and quartz. The...the field of low-pressure pumpellyite from North Wales (Bevins & Merriman, 1988) and might be the result...the southern belt contain variable amounts of stilpnomelane, Na-Ca amphibole, chloritoid, plagioclase (albite)...consists of white mica, chlorite, actinolite and stilpnomelane formed at about 1-4.5 kbar (Zhang, 1989), obviously...prehnite-pumpellyite facies assemblages in the Tal y Fan metabasite intrusion, North Wales: implications for Caledonian |  | | Journal (article/letter/editorial) | | LVA = pumpellyite = quartz = riebeckite = stilpnomelane = trcmolite = titanite = H20 = low-variance...the selected samples from petrographical s t u d y seem to be completely reequilibrated at the given...Pumpellyite-tumingmetuwrphic units of the Iiguria. P U M P E L L Y I T E A N D C O E X I S T I N G M I N E R A L S FROM...commonly associated with the studied assemblages. Stilpnomelane and acicular rude OCCUT in acidic rock. Lawsonite...luted in Table 2. The formulae am recalculated to X,Y,(Si. AI),O,,(OH).considerining Fe3+=3-Alw-Ti and using |  | | Journal (article/letter/editorial) | | ST- C R E E NS C H I S 1 T H E R M06 A R 0ME l R Y Each term in square brackets is the fraction of a...also contain albite, calcite, titanite and stilpnomelane. Note that the common occurrence of calcite... In addition, albite, titanite, quartz and stilpnomelane or biotite are also common minerals in the greenschist...abundant carbonate. M E T A M O R P H I C H I S T O R Y OF T H E M A T A C H E W A N AREA The prehnite-pumpellyite...prehnite-pumpellyite facies assemblages in the Tal y Fan metabasite intrusion, North Wales: implications for Caledonian |  | | Report (issue) | | BRITISH GEOLOGICAL SURVEY British Regional Geology Wales ll/1 F Howells ©t\/ERC2007 BRITISH GEOLOGICAL...Keyworth, t'--lotti ngha m t'--IG 12 5GG Printed in the UK by Halston Printing Group, Amersham, Buckinghamshire...13 Avalon Terrone 20 Coedana Complex South-west Wales and the borders 3 Cambrian 24 25 St David's...30 31 32 33 Geology of \/Vales 2 Topography of Wales 3 Distribution of continents in Late Proterozoic...Tuff Formation 63 Bedded Pyroclastic Formation, Crib y Ddysgl 64 N\ineralisation and the Lower Rhyolitic |  | | Journal (article/letter/editorial) | | Chlorite Epidote Titanite Albite White mica Stilpnomelane Hematite Augite (igneous) x x x x x x x...K2O P2O5 SO3 LOI Total Trace element (p.p.m.) Rb Sr Y Zr Nb Ba La Ce Pr Nd Hf Pb Th U <5% x 47.48 1.83... nd 48 31 98 10 13 7 17 5 9 5 3 1 4 mica, stilpnomelane, sodic amphibole and actinolite. Small (<100...Al2O3 13608 13611 13612 13609 13613 Fe2O3 CaO Y/15 (b) N-MORB 13612 13608 13613 13611 13609 La/10...Trace element data from the five samples plotted on a Y ⁄ 15-La ⁄ 10-Nb ⁄ 8 ternary plot (Cabanis & Lecolle |  | | Journal (article/letter/editorial) | | Hbl Kln Kfs KY Mnt Muscovite Pyrophyllite Stilpnomelane Talc Wollastonite Yugawaralite Ms Prl Stp TIC...constraints provided by Schreine497 498 M . F R E Y , C . DE C A P l T A N l 81 J . G . LlOU Table 1...0-500" C and the pressure range 0.1-10 kbar. MODEL S Y S T E M S CASH The following 11 phases were considered...together in a small P-T field only. 504 M. F R E Y , C . DE C A P l T A N l & J . C . LlOU (9) For tremolite...5 & 6a) is shown with heavy lines. 506 M. F R E Y , C . DE CAPlTANl 81 J . C . LlOU range are reactions |  | Stephenson, D., Bevins, R. E., Millward, D., Highton, A. J., Parsons, I., Stone, P., Wadsworth, W. J. (1999) Chapter 6: Wales and adjacent areas. In Caledonian Igneous Rocks of Great Britain (Geological Conservation Review Series - Geological Conservation Review No. 17. Joint Nature Conservation Committee, Peterborough. p.231-344. | Book (chapter) | | Survey, Edinburgh R.E. Bevins National Museum of Wales, Cardiff D. Mi award British Geological Survey,...British BG5 Geological ,835 Survey Chapter 6 Wales and adjacent areas Introduction INTRODUCTION...Bevins Geological setting In early Ordovician times Wales lay at a latitude of approximately 600 , in the...wide, which was to dominate the palaeogeography of Wales for over 100 million years. During mid-Ordovician...early as Caradoc times in this sector of Iapetus. Wales was a part of this microcontinent (Soper, 1986) |  | | Book (edition) | | Kirby, Wirral, UK Printed by Berforts Information Press, Stevenage, Hertfordshire, UK Downloaded from...Phlogopite–Biotite, Lepidolite, Zinnwaldite 181 Stilpnomelane 199 Pyrophyllite 202 Talc 204 Chlorite Group...percentage on an atomic basis b cell edge in the y direction acute bisectrix Bxa c cell edge in the z...ontmatter.pdf by guest T tr. VHN100 wt.% XRD x, y, z Z 2V a, b, g a, b, g d e o & temperature. Also...between the positive directions of the y and z, x and z, and x and y crystal axes birefringence extraordinary |  | | Book (volume) | | Society, Burlington House, Piccadilly, London W1V OJU, UK. The Society is a Registered Charity, No. 210161...Brassmill Enterprise Centre Brassmill Lane Bath BA1 3JN UK (Orders: Tel. 01225 445046 Fax 01225 442836) Distributors...Typeset by Type Study, Scarborough, UK. Printed by The Alden Press, Oxford, UK. Australia (Orders: Tel. (08)...Howieite 741 742 751 Index 759 hetig? . - —y ts a ays Pew 7 2 ne tant, av Hotbe ee 8 Ss...percentage on an atomic basis b cell edge in the y direction Bx, acute bisectrix cell edge in the z direction |  | | Report (volume) | | SILICATE STRUCTURES Island structures Zussmanite Stilpnomelane Parsettensite Bannisterite Strip structures...described in terms of a larger shaped base in which the Y axis and line cell in are a = b # with the Z axis...cell in The la). Fig. axial repeat along this Y axis is b © af3, and the cell volume is twice that...second layer by +b/3 along any of the three hexagonal Y axes of the initial layer (defined as normal to the...along each of the three Y axes give identical results so that the particular Y axis used is immaterial |  | | Book (chapter) | | Memorial Building, Queens Road, Bristol BS8 lRJ, UK Blackwell Science NORTHWEST MISSOURI STATE UNIVERSITY...recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without...Geology, National Museu111 of Wales, Cathys Park, Cardiff CFl JNP, UK D.R. Peacor Department of Geological...Memorial Building, Queens Road, Bristol BS8 IRJ, UK N. Ctauer Centre de Geochimie de la Surface (CNRS-LILP)...& Robinson (1993) to show, in metabasites fron1 Wales, that the change from prehnite-pumpellyite to prehniteactinolite |  | | Report (volume) | | REVIEWS in MINER ALOGY & GEOCH EMISTR Y 1955 Volume 56 EPIDOTES EDITORS : Axel Liebscher & Gerhard...* includes all trivalent rare earth elements and Y; the corresponding monoclinic endmembers and minerals...parallel to the crystallographic b axis. Also the fan shaped growth of zoisite in segregations (Brunsmann...members of the Al-Fe3+ solid solution series have Y parallel to [010], X approximately parallel to [001]...weak to distinct and its scheme is X = pale yellow, Y = greenish yellow, and Z = yellowish green (Burns |  | | Book | | Experimental Data on Element Distribution. Sr, Ba, Ca, Y, Eu 2 +, Eu3+, and Other Rare Earths Between Plagioclase...3 90 Degrees 90 87.7 90.3 87.7 91.2 90 92.1 90 y or P 21 P2dm CI CI cI PI I2jc CI C2jm Space group...superstructure o f- - - _ ...!-- 1-'--- discon tinuil y 01 An50 bel ween e2 ond e I vor ieties micrometer...",,1 ""0: ,'"9' .... ..../ :/,",' ::' ••-,,' ,,y liP ..../ ••• K'6 400 " Ve!'l" " ./ .. ,t...o-Q.' • : \~ '.0. •• e!'1" :~o9e!' .... ~\.\\\\\-:"~Y. ••' ~Hutten-·•• / :' \\,\" •• - • •••• .~ locher |
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