ORES OF THE NORTHERN PENNINES, THE LAKE DISTRICT AND NORTH WALES

1976 ◽  
pp. 197-230 ◽  
Author(s):  
P.R. INESON
Keyword(s):  
Lake District ◽  
North Wales

V.—Notes on Geological Sections, within Forty Miles Radius of Southport

1883 ◽  
Vol 10 (11) ◽  
pp. 500-507
Author(s):  
Charles E. De Rance
Keyword(s):  
The Other ◽  
Irish Sea ◽  
Lake District ◽  
North Wales ◽  
The Irish Sea ◽  
The One ◽  
Carboniferous Limestone ◽  
Sea Coast

Striking a radius of 40 miles from Southport, the line will be seen to intersect the sea-coast near the Silurian districts of Ulverstone in North Lancashire, and Colwyn Bay in North Wales. The succession in both cases is very similar, Denbighshire Grits and Flags of the one area corresponding in time to the Coniston Grits and Flags of the other; and just as the Silurians of the Lake District are overlaid by a fringe of Carboniferous Limestone, so the Silurians of Diganwy are overlaid by the Carboniferous Limestone of the Great and Little Ormes Head. Laid upon a floor of Silurian rocks, the Carboniferous Limestone may be regarded as extending continuously under the Irish Sea, and underlying the various Carboniferous and Triassic rocks now occupying Lancashire.

The lost Lower Old Red Sandstone of England and Wales: a record of post-Iapetan flexure or Early Devonian transtension?

2003 ◽  
Vol 140 (6) ◽  
pp. 627-647 ◽  
Author(s):  
N. J. SOPER ◽  
N. H. WOODCOCK
Keyword(s):  
High Heat ◽  
Sediment Provenance ◽  
Lake District ◽  
East Anglia ◽  
Early Devonian ◽  
England And Wales ◽  
Red Sandstone ◽  
Scottish Highlands ◽  
North Wales ◽  
Slate Belts

Illite crystallinity data from the Silurian slate belts of England and Wales indicate anchizone to low epizone metamorphism during the Acadian deformation in late Early Devonian time. This metamorphic grade implies a substantial overburden, now eroded, of Lower Devonian non-marine sediments of the Old Red Sandstone (ORS) magnafacies. A minimum 3.5 km pre-tectonic thickness of ‘lost’ ORS is estimated in the southern Lake District and comparable thicknesses in North Wales and East Anglia. Tectonically driven subsidence of the underlying Avalonian crust is required to accommodate such thicknesses of non-marine sediment. One proposed mechanism is flexure of the Avalonian footwall during convergence that continued from Iapetus closure in the Silurian until Acadian cleavage formation in the Emsian. The evidence for this model in the critical area of northwest England is reviewed and found to be unconvincing. An alternative model is developed following a recent suggestion that the Early Devonian was a period not of continued convergence but of orogen-wide sinistral transtension. Transtensional accommodation of the lost ORS is evidenced by Early Devonian extensional faults, by synchronous lamprophyric magmatism, and by compatibility with previously diagnosed sediment provenance patterns. A summary of Siluro-Devonian tectonostratigraphy for Britain south of the Highland Border emphasizes that, unlike the Scottish Highlands, this area was not affected by the Scandian Orogeny, but was by the Acadian. An important period of sinistral transtension in the Early Devonian (c.420–400 Ma) was common to both regions. This was a time of high heat flow, lamprophyric and more evolved magmatism, and major southward sediment transport, involving mainly recycled metamorphic detritus from the Highlands and from contemporaneous volcanicity. Old Red Sandstone, deposited in coalescing transtensional basins over much of Britain from the Midland Valley to the Welsh Borders, was largely removed and recycled southward during Acadian inversion.

scholarly journals XX.—A Bathymetrical and Geological Study of the Lakes of Snowdonia and Eastern Carnarvonshire

1905 ◽  
Vol 40 (2) ◽  
pp. 419-467 ◽  
Author(s):  
T. J. Jehu
Keyword(s):  
Geological Survey ◽  
Inland Waters ◽  
Lake District ◽  
Ordnance Survey ◽  
Adequate Knowledge ◽  
Geological Surveys ◽  
North Wales ◽  
English Lake District ◽  
The Government ◽  
Geological Research

The study of lakes has received more attention on the Continent than it has in our own country. The inland waters of France and Switzerland have been most carefully surveyed, and in America accurate soundings of many of the lakes have been made by the Geological Surveys. But until recent years this work has been almost altogether neglected in Britain; the Government had considered it to be outside the function of the Ordnance Survey, and though of importance to geological research, it has not been undertaken by the Geological Survey. The absence of adequate knowledge concerning the forms of the basins occupied by the lakes has been a serious obstacle to the geological inquiry as to the mode of origin of these basins. But recently, in the English Lake District and in Scotland, this obstacle has been removed to a great extent through the work of geographers, who have carried out a very complete bathymetrical survey of many of the lakes of those regions; and the importance of this work has been recognised by geologists. But in North Wales not only had no attempt been made to ascertain the configuration of the lake-beds, but in many cases even the depths of the lakes remained unknown.

scholarly journals Sedgwick Museum Notes. A New Azygograptus from North Wales

1922 ◽  
Vol 59 (7) ◽  
pp. 299-301 ◽  
Author(s):  
Gertrude L. Elles
Keyword(s):  
The Other ◽  
Lake District ◽  
North Wales ◽  
The One

The graptolite here described was discovered first in the St. Tudwal's peninsula by Mr. T. C. Nicholas in 1912 in the Llanengan Mudstones, but it was not then regarded as distinct from Azygog. lapworthi, though it seemed to possess certain features not recognizable in the Lake District specimens, the only area from which that species had been previously recorded. The discoveryof numerous other specimens by Dr. Matley in the Lleyn peninsula and by Dr. Greenly in the Bangor area has served to show that the characters wherein this species differed from Azygog. lapworthi are permanent and of specific value, and since, moreover, it occurs at a distinctly higher horizon than Azygog. lapworthi, being characteristic of about the middle of the zone of Didymog. extensus, a description of it seems advisable. In general it has been noted that it is in many respects intermediate in character between Azygog. lapworthi on the one hand and Azygog. suecicus on the other, and it is perhaps significant that it occurs upon an horizon between the two.

The Late Devensian flora and vegetation of Britain

1977 ◽  
Vol 280 (972) ◽  
pp. 247-271 ◽  
Keyword(s):  
Soil Disturbance ◽  
Regional Differentiation ◽  
Vegetation Composition ◽  
Lake District ◽  
14C Dating ◽  
Mountain Glaciers ◽  
Surface Samples ◽  
North Wales ◽  
Pollen Diagrams ◽  
Species Lists

For the period ca. 15000-10000 years ago, which spans the interval between the latest presence of lowland ice and the final disappearance of mountain glaciers from Britain, so many botanical data are now available that it is possible to analyse plant distributions and vegetation composition in detail not yet possible for earlier periods. Species lists, provided by identification of pollen and of macroscopic remains, show a combination of diverse phytogeographic elements into an assemblage characteristic of the period - an admixture of apparently thermophilous plants with those now found in northern and arctic situations, and of oceanic and steppe elements. Ordination of data on floras has revealed much similarity between the regions of Britain, but pollen analysis continues to emphasize how strong must have been the regional differentiation of vegetation. A comparison of pollen diagrams published since 1970, from sites lying on a broad north-south transect of western Britain, shows much variety in the pollen assemblage zones which have been distinguished, and in the vegetation interpreted from the pollen data by comparison with surface samples and modern vegetation. Sufficient 14C dating is now available, however, to permit chronostratigraphic correlation of these pollen zones, and to show that there is consistent evidence for climatic amelioration at about 13000 B.P., and rapid deterioration at about 11000 B.P., leading to conditions of incomplete vegetation cover and universal soil disturbance which can be correlated with geomorphological evidence for the recrudescence of mountain glaciation in western Scotland, the Lake District, and North Wales, in the period called Younger Dryas on the continental mainland. Between 13000 and 11000 there is in western Britain evidence for a woodland biozone, or palaeobotanical interstadial, equivalent to Bolling plus Allerod of continental stratigraphers (Mangerud, Andersen, Berglund & Donner 1974), and divided by a very minor regression of vegetation during Older Dryas time ( ca. 12000-11800). The now closely 14 C-dated site at Low Wray Bay, Windermere, is described in detail, and suggested as a reference site for this interstadial.

scholarly journals V.—Notes on the Ash-Slates and Other Rocks of the Lake District

1892 ◽  
Vol 9 (4) ◽  
pp. 154-161 ◽  
Author(s):  
W. Maynard Hutchings
Keyword(s):  
Lake District ◽  
Fine Grained ◽  
North Wales

Whilst studying the sedimentary roofing-slates of North Wales and Cornwall, and allied materials, my attention was also directed to those most interesting rocks, the ash-slates of the Lake District, often externally so closely resembling some of the Welsh and Cornish examples, though differing so much in origin. In course of time I have collected, and had sections prepared from, a considerable number of specimens from many quarries and other places at various parts of the district, both very fine-grained wellcleaved actual roofing-slates and also the attendant coarser beds.

Geological setting of the useful minerals in Britain

1974 ◽  
Vol 339 (1618) ◽  
pp. 273-288 ◽  
Keyword(s):  
Ferrous Metal ◽  
Lake District ◽  
East Anglia ◽  
South Wales ◽  
North Wales ◽  
Lead And Zinc ◽  
Lead Zinc ◽  
Lower Palaeozoic ◽  
Sand And Gravel ◽  
Orogenic Belts

Great Britain was endowed with mineral wealth out of proportion to its small size. This is partly the result of its situation at the crossing-place of two of the three major European orogenic belts, the Caledonian and Hercynian, but perhaps more the result of the intense circulation of hot mineralizing fluids in systems of tension faults which were active at inter­vals from early Permian to Tertiary or possibly even to Neogene times. In the peninsula of Cornwall and Devon, tin, copper, tungsten and other non-ferrous metal deposits bear some relation to the Hercynian posttectonic granites. In areas of Lower Palaeozoic slaty rocks in central and northern Wales, the Lake District and the southern Uplands of Scotland, lead, zinc, and copper deposits occur, but many of them were emplaced in post-Carboniferous times. The Lower Carboniferous uplands of Mendip, north Wales, north Derbyshire and the northern Pennines are all highly mineralized, with lead and zinc, and in the Pennines fluorite, barite and witherite also appear in quantity. All deposits so far mentioned are epi­genetic, i. e. emplaced later than the enclosing rocks. This also applies to the hematite deposits formerly worked in Carboniferous Limestone in west and south Cumberland and Furness, and those now working in south Wales. Mineral deposits which form part of the enclosing rock-sequence include the Permian dolomite–anhydrite–halite–sylvine evaporites of northeast England; the Triassic halite deposits particularly in Cheshire; and the siderite–chamosite ironstone in the Jurassic belt extending from Cleve­land through Scunthorpe to Banbury. In addition, large tonnages of hard rocks are quarried in Scotland, Wales, northern and north-midland England and the Cornubian peninsula; and sand and gravel is worked from Pleistocene glacial deposits and Holocene alluvials, especially in the London district, East Anglia and the Trent valley.

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