 | | Journal (article/letter/editorial) | | The Adon Group ('Arvonian') of North Wales A. J. Reedman, B. E. Leveridge and R. B. Evans REEDMAN, A...EVANS, 1984. The Arfon Group ('Arvonian') of North Wales. Proc. Geol. Ass. 9S (4), 313- 321. The Arfon Group...sedimentary sequence in the area around Bangor in North Wales. It records a period of dominantly acidic volcanism...Geological Survey in the Bangor district of northwest Wales has led to the definition of new lithostratigraphical... Typically the tuffs consist of phenocrysts of quartz and sodic plagioclase in a matrix of devitrified |  | | Journal (article/letter/editorial) | | entitled "Outline of the Geological Structure of North Wales," read before the Geological Society, June 21, 18~3...Carnaxvon are among the very oldest rocks of North Wales; of course," he adds, " e x cepting the crystalline...well-defined base for the Cambrian series of North Wales, unless we take the metamorphic rocks as a kind...time the Geological Survey was at work in North Wales, and Jukes was in correspondence with Sedgwick....opinion that many of the crystalline rocks of North Wales and other districts " belong to a more remote age |  | | Journal (article/letter/editorial) | | Port Dinorwic" before the Geological Society, and described the conglomerate in the Twt Hill quarry. "...constituent." " The lowest rock exposed in the Twt Hill quarry is of the same type as that at Twt Hill. Above...of the quarry, and had mistaken the patches of conglomerate sticking to the face of the quarry for alternating...into brown sandstones on the S.S.E. rim of the quarry, and was the basement bed of the Cambrian, resting...matter perfectly clear, I give a ground-plan of the quarry (Fig. 1). Prof. Bonney's section, to which the |  | | Book | | 201784243 V A record block of granite at Polkanuggo Quarry, Cornwall, in September 1902. 110 pounds (50 kg)...Street, Princes Risborough, Aylesburv, Bucks HP17 9AJ, UK. British Library Cataloguing in Publication data...copyright reserved), 7, 11 (lower), 15, 18, 29; Gwynedd Archives Service, 24; C. J. Hall, 11 (upper); Sam...are from the authorās collection. COVER; Weston Quarry, Portland. Several firms specialised in manufacturing...loading kerb stones on to a wagon at a granite quarry near Penryn, Cornwall, in the late nineteenth century |  | | Journal (article/letter/editorial) | | 13arts--the mass near Caernarvon, the mass near Dinorwic, and that nearBangor;--Prof. Hughes considers...may find a key to interpret the rest. The "field-quarry" at Twt Hill has been the scene of much controversy...the "porphyry" intrusive. I have examined this quarry many times, with the care that is due to its importance...again, as noted by Prof. Hughes. Then there is the quarry mentioned by that author by the side of a new road...said to dip, as at Twt, to E.S.E. At a disused quarry in a field by Tygwyn is another exposure of conglomerate |  | | Report (issue) | | Caledonian structures in the Cambrian Slate Belt, Gwynedd, North Wales. B. C. Webb. 1 The Cambrian - Ordovician...Ordovician boundary between Aber and Betws Garmon Gwynedd, North Wales. A. J. Reedman, B. C. Webb, B. E. Leveridge...the Snowden and Crafnant Volcanic groups, North Wales. M. F. Howells, B. E. Leveridge, R. Addison and...Caledonian structures in the Cambrian Slate Belt, Gwynedd, North Wales B. C. Webb The Cambrian has been divided... It may be inferred along the Aber-Dinlle and Dinorwic fault complexes, which defined the north-west |  | | Book | | A Mineralogy of Wales RfCHARD E. BEYfNS Ocpartmellf o[Geolngy, Nmin11a/Museum of\Valcs, Cardiff AMGUEDDFA...Colliery, Ponh, Mid Glamorgan. National Museum of Wales specimen 48.264.GR 175. ex Cymmer Welfare Library...CE 6 I CES IN WALES 9 30 127 138 6 INTRODUCTION The mineralogy of Wales is diverse. with over...reveal the presence of additional species new to Wales. and perhaps new to the British Isles. It is also...completely new to cience will be discovered in Wales. as techniques for analysing specimens become ever |  | | Journal (article/letter/editorial) | | Ordovician detrital zircon geochronology of North Wales Hayley D. Pothier a, John W.F. Waldron a,ā, David...Columbus House, Greenmeadow Springs, Cardiff CF15 7NE, UK a r t i c l e i n f o Article history: Received...Precambrian to Ordovician sedimentary basins of Wales display contrasting histories across major NE-striking...mosaic of terranes, including most of England, Wales, southern parts of Ireland, and much of Atlantic...Lk New Brunswick Ireland Ln Meguma Terrane Wales MP Rs Newfoundland WB 0 A Ag England 250 |  | | Report (issue) | | molybdenum deposit...................... Pass Lake Road quarry. . . . . . . . . . . . . . . . . . . . . . . ..... . . . . . . . . . . . . . . Rock exp osur e (quartz crystals, pyrite, jasper) . . . . . . . . . . ...43 43 - iii CONTENTS (cont.) Page Eagle Lake quarry . . . . . . . . . . . . . . . . . . . . . . . .... . . . . . . . . . . . . . . . . . Greer Lake quarry............ . . . . . . . . . . . . . . . . . .... . . . . . . . . . . . . . . . . . . . . . . Dinorwic area (northern part).................... Eagle |  | | Journal (article/letter/editorial) | | Geological Survey, Keyworth, Nottingham NG12 5GG, UK ABSTR ACT Brinrobertsite, an ordered, mixed-layered...near Bangor, N Wales. It comprises ~30% of the metabentonite, in association with quartz (~50%) and chlorite...British Geological Survey, Keyworth, Nottingham, UK, and Department of Geology, Miami University, Oxford...exposures, 750 m NE of Penrhyn castle, near Bangor, N. Wales, United Kingdom, (National Grid reference: SH 60907235)...Ffrancon Formation in this part of the Aber-Dinlle-Dinorwic fault system. A nearby dolerite sheet, up to 100 |  | | Report (issue) | | map of north-west Wales Third order regional Bouguer anomaly map of north-west Wales Third order residual...residual Bouguer anomaly map of north-west Wales Residual Bouguer anomaly map of the Penmynydd Zone Total...Total field aeromagnetic map of north-west Wales Residual Bouguer anomaly map of the Penmynydd Zone with...Anglesey is separated from the north-west coast of Wales by the Menai Strait (Figure 1). Additional place...Gwna Group sediments. It comprises mica schists, quartz schists and limestones together with a series of |  | | Report (issue) | | and Stone Co Ltd; Maen Offeren Slate Quarry Co Ltd; Mill Hill Quarry (Tavistock) Ltd; Old Delabole Slate...Ltd; Penrhyn Quarries Ltd; Pen-yr-Orsedd Slate Quarry Co Ltd; Solite Ltd; Tanner and Hall Ltd. Metric...exploitation is now confined to Cornwall, Devon, North Wales and the Lake District. The traditional use for slate...largest operation is the massive Penrhyn Quarry in North Wales. The largest concerns in the Lake District...are known to be active in Cornwall, Devon, North Wales and the Lake District. No slate production is now |  | | Journal (article/letter/editorial) | | The Caledonoid faults of northern Lleyn (North Wales) W. E. TREMLETT Summary. Evidence of substantial...scattered crystals of epidote and small veins of quartz and haematite. The analysed rock used for Table...when movements are known to have occurred on the Dinorwic Fault and some of the Caledonoid faults of Anglesey...position to represent the western continuation of the Dinorwic Fault of eastern Caernarvonshire, but this link...of northern Lleyn 245 7 km north-west of the Dinorwic Fault. These fractures in eastern Caernarvonshire |  | | Journal (article/letter/editorial) | | conglomerate, (1) a granitoid series, (2) amass of quartz felsites representing old rhyolitic lavas, (3)...granite (and that carries some of the rock at Port Dinorwic), how do we explain the immediate succession to...series which extends from Twt Hill to above Port Dinorwic. There are certain grits and conglomerates exposed...Carnarvon, and lastly near Careg Goch, above Port Dinorwic: these he holds to be one and the same set of...occasional appearance of fragments of schist among the quartz pebbles, which chiefly compose the conglomerate |  | | Journal (article/letter/editorial) | | Early Palaeozoic sedimentation and tectonics in Wales N. H. Woodcock WOODCOCK, N. H. 1984. Early Palaeozoic...structural and sedimentological work in Lower Palaeozoic Wales is reviewed. The present structural geometry probably...PAPER secondary bending, late Caledonian in North Wales (Helm et al. , 1963) and Variscan in the south (Pringle...faults in Wales parallel the fold and cleavage trends; for example the Church Stretton , Dinorwic and Berw...sedimentological and structural results in Lower Palaeozoic Wales and to tectonic models for the Welsh Basin. It avoids |  | | Journal (article/letter/editorial) | | polytypes in pelitic rocks of Snowdonia and Ll n, North Wales R. J. MERRIMAN British Geological Survey, Keyworth...London W1P 1PA ABSTR ACT. Pelitic rocks in North Wales, ranging in age from late Precambrian to Silurian...pelitic rocks, mica, crystallinity, Snowdonia, Ll~n, Wales. RECENT work by Roberts (1981) on assemblages in...overlying Minffordd Formation crops out between the Dinorwic and Aber-Dinlle faults and consists of conglomerates...the most important of which are the Bangor and Dinorwic faults, the Aber-Dinlle fault, and the Nefyn fault |  | | Report (chapter) | | July 10, 2015 The Ordovician marginal basin of Wales B. P. Kokelaar, M. F. Howells, R. E. Bevins, R....Caledonides. In Wales, the Ordovician volcanic activity shifted in time and space. In S Wales volcanism persisted...from the middle Arenig through the Llanvirn. In N Wales the volcanism can be broadly divided into dominantly...episode in central and northern Snowdonia. In eastern Wales, including the Welsh Borderland, and in Ll~,n, both...Ordovician igneous rocks in Wales and the Welsh Borderland are shown in Fig. 1. In N Wales these rocks were first |  | | Journal (article/letter/editorial) | | Series between Twt Hill, Caernarvon, and Port Dinorwic." By the Eev. Prof. T. G. Bonney, M.A., F.K.S...series extended up to a little beyond Port Dinorwic, where the quartz-felsite set in. The paper described the...Geological Society on a new " Cambrian " find in North Wales. The paper appeared, and the "Cambrian" turned out |  | | Journal (article/letter/editorial) | | the Lower Carboniferous Conglomerates of North Wales." By Aubrey Strahan, Esq., M. A., F.G.S., and Alfred...resemble the Upper-Ludlow beds of Kendal and Central Wales. The authors discuss the origin of the pebbles,...with a high objective, is resolved into grains of quartz, with an interstitial ingredient having but little...also numerous nests and fissure-like groups of quartz-grains disseminated throughout, and sometimes angular...and includes now, in addition to the central or quartz-felsite ridge, the whole of the rocks marked in |  | | Journal (article/letter/editorial) | | undoubted Cambrian conglomerates; and yet near Port Dinorwic beds, probably of the same age as those at Twt...That this conglomerate consists of " pebbles of quartz imbedded in a felspathio matrix," which removes... look for these in the outcrops near to Port Dinorwic, which have far more bearing on the question ...(a) are distinctly bedded quartz-grits or quartzites containing sometimes quartz pebbles up to the size...into a band about half a yard thick, which is a quartz-felspar crystalline-looking rock (c), not unlike |  | | Journal (article/letter/editorial) | | greater. The fault structures found in other parts of Wales are compared to those of the Shelve Inlier, and...that this style of faulting was of importance in Wales, though it was mostly of pre-Silurian age. The significance...Formation (a formation which comprises brittle quartz lithic arenite) in the vicinity of the Bog Mine...important process throughout Lower Palaeozoic times in Wales. Other workers (e.g. Nutt and Smith 1981a; Gibbons...(1984a, b) has given evidence for dextral slip in Wales (at least for the late Ordovician strike-slip events) |  | | Book | | IDLANDS 8UCKJNGHAMSH IRE CAMBRIDGESHIRE 60 GWYNEDD POWYS 149 151 156 SCOTLAND 159 Key map 160 BORDERS...75 DERBYSH IRE 79 SHROPSH IRE 133 134 135 137 WALES Ke-y map LEICESTERSH IRE 27 30 SOMERSET W EST...considerations. And in son1e areas, such as parts of South Wales, local authorities are concerned to wipe the countryside...eastern England, n1idland England, northern England, Wales and Scotland. Within the areas, entries are by county...Gloucestershire 28 Oxfordshire 29 Buckinghamshire WALES 1 Clwyd 2 Gwynedd 3 Powys 4 Dvfed , 5 West Glamorgan 6 Mid-Glamorgan |  | | Book | | ) PLATE I, FRONTISPIECE THE MINERAL WEALTH WALES AND ITS EXPLOITATION TREVOR M. THOMAS M.SC.,...the Geology Department of the National Museum of Wales have always been placed at the disposal of the author...Geography and Anthropology, University College of Wales, Aberystvryth, for his sustained interest during...Keeper of the Geology Department, National Museum of Wales, kindly assisted in the selection of some of the... 1 WEALTH AND COAL MINING IN THE SOUTH WALES II COALFIELD RECENT TRENDS GENERAL CONSTITUENT |  | | Journal (article/letter/editorial) | | the Mid Mississippian palaeogeography of North Wales, UK JEREMY R. DAVIES1*, NICK J. RILEY2 and DAVID WILSON3...Aberystwyth, SY23 3DB, UK 2 British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK 3 Pant-yr-hogfaen...Pant-yr-hogfaen, Llanrhystud, Ceredigion, SY23 5EH, UK The isolated outlier of Visean (Mid Mississippian) limestones...limestones and sandstones near Corwen, North Wales, UK, provides a critical constraint on regional tectonic...of two of the main marker beds within the North Wales Visean succession (Main Shale and Coral Bed) together |  | | Journal (article/letter/editorial) | | I V . ā T H E A G E OF FLOATING I C E IN NOBTH WALES. 1 By D. MACKINTOSH, F.G.S. Sea-coast Fringe of...stones in general may be found porphyry, felstone, quartz, Cambrian conglomerate, foliated Cambrian rocks...District at a time when the N.W. of England and Wales was deeply submerged. The greater part of the drifts...of the highest excavation of the Alexandra slate quarry to within a few yards of the rock-crested summit...breccia and ashes from a greater or less distance; quartz and a rock resembling gneiss from the N.W. side |
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