The Geology of England and Wales: A Concise Account of the Lithological Characters, Leading Fossils, and Economic Products of the Rocks; with Notes on the Physical Features of the Country |
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Page 7
... places - in one locality chalk , in another sandstone ; here clay , there slate or limestone ; but the difficulty is to comprehend the relation that one rock bears to another , and to understand their sequence . The relations of the ...
... places - in one locality chalk , in another sandstone ; here clay , there slate or limestone ; but the difficulty is to comprehend the relation that one rock bears to another , and to understand their sequence . The relations of the ...
Page 9
... places underneath . those at a lower level . Indeed , we find as a rule , that the older the rocks , the more wild ... place before the layers above were deposited : this is called an unconformability , and is a sure indication of a long ...
... places underneath . those at a lower level . Indeed , we find as a rule , that the older the rocks , the more wild ... place before the layers above were deposited : this is called an unconformability , and is a sure indication of a long ...
Page 13
... places , but that the forms of life whose existence depends largely upon the con- ditions , likewise vary in different localities . Distinct faunas may be separated by narrow barriers in existing seas ; and differences almost as great ...
... places , but that the forms of life whose existence depends largely upon the con- ditions , likewise vary in different localities . Distinct faunas may be separated by narrow barriers in existing seas ; and differences almost as great ...
Page 35
... places it on the horizon of the Ffestiniog beds . Malvern Shales . Above the Hollybush Sandstone comes the Black Shale ' of Malvern . This deposit consists of thinly laminated black carbonaceous and pale greenish shale , from 500 to ...
... places it on the horizon of the Ffestiniog beds . Malvern Shales . Above the Hollybush Sandstone comes the Black Shale ' of Malvern . This deposit consists of thinly laminated black carbonaceous and pale greenish shale , from 500 to ...
Page 36
... places the beds with the Dolgelly rocks . UPPER CAMBRIAN ( Sedgwick ) . LOWER SILURIAN ( Murchison and Geol . Survey ) . ARENIG ROCKS . ( Sedgwick . ) LOWER LLANDEILO . ( Murchison . ) The Arenig mountains of Merionethshire give their ...
... places the beds with the Dolgelly rocks . UPPER CAMBRIAN ( Sedgwick ) . LOWER SILURIAN ( Murchison and Geol . Survey ) . ARENIG ROCKS . ( Sedgwick . ) LOWER LLANDEILO . ( Murchison . ) The Arenig mountains of Merionethshire give their ...
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Common terms and phrases
30 feet Ammonites attain a thickness Bala bands breccia Bunter calcareous Cambrian carbonate Carboniferous Limestone Chalk Clay cliffs coal Coal-field colour conglomerate consist containing Coral Rag Crag denudation deposits Derbyshire Devon Devonian district divisions Dorsetshire escarpment Estuarine feet in thickness flags flagstones flints Forest formation formed fossiliferous fossils freestone Fuller's Earth Gault geological Glacial gravel grey igneous Inferior Oolite Judd Keuper Kimeridge lime Lincolnshire Lingula lithological Llandovery localities lower beds Lower Greensand Lower Lias Magnesian Limestone Malvern Marl Mendip Hills Millstone Grit Mollusca mottled Murchison nodules North Northampton Sand occur Old Red Sandstone organic remains Ostrea palæontological Palæozoic pebbles Permian Phillips places portion Prof Pterygotus quarried Ramsay Red Marl Rhætic beds Rhynchonella rocks sand sandy seams Sedgwick shales shelly shire Silurian slates slaty Somersetshire sometimes South Wales species stone strata term thin Triassic unconformably Upper Greensand Upper Lias Vale valley Wealden Wenlock Yoredale Yorkshire
Popular passages
Page 454 - FREDERICK M°CoY, FGS One vol., Royal 410. Plates, /i. is. A CATALOGUE OF THE COLLECTION OF CAMBRIAN AND SILURIAN FOSSILS contained in the Geological Museum of the University of Cambridge, by JW SALTER, FGS With a Portrait of PROFESSOR SEDGWICK.
Page 433 - The variation of species, and natural selection or the survival of the fittest in the struggle for existence, are Natural History facts, and the consideration of these facts as brought prominently into notice by Darwin, has led to the doctrine of the Evolution of Life being regarded as the " Fundamental Truth of Biology." When, therefore, we hear the subject treated...
Page 386 - Conein-coue,' as the seam of ironstone breaks into conical forms with the bases of the cones at top and bottom of the seam, and their apices pointing inwards towards each other. The surfaces of these cones are corrugated by small horizontal fretted wavelets, or ridges, rather resembling those on the outside of some stalactites, and each cone is concentrically enveloped by several coats, the surface of each being similarly corrugated.
Page 365 - ... in a horizontal or nearly horizontal direction, following the sweep of the hillside whether curved or straight. The boundary line between these several strips may have been originally only a mathematical one, connecting, say, two mere-stones, and yet a bank will soon have been formed along it. For each upper cultivator will naturally have taken care not to allow the soil of his strip to descend to fertilize his neighbour's below. He would draw the lower limit of his strip by a reversed furrow,...
Page 117 - The boundary between them may be roughly marked off by a line running from the mouth of the Tees to the mouth of the Exe.
Page 302 - Upward of 200,000 years ago the earth — as we know from the calculations of astronomers — was so placed in regard to the sun that a series of physical changes was induced which eventually resulted in conferring upon our hemisphere a most intensely severe climate. All northern Europe and northern America disappeared beneath a thick crust of ice and snow, and the glaciers of such regions as Switzerland assumed gigantic proportions.
Page 21 - Now does this mean that it may have been two, or three, or four hundred million years ? Because this really makes all the difference.
Page 286 - ... extending from the river Aide on the north, to the southern extremity of the deposit in Essex. Of these four stages, the 4th is the most constant and important, the 1st, 2nd, and 3rd being frequently either concealed by, or destroyed during the formation of, the succeeding stages. At Walton-on-the-Naze alone do any of the four lower stages contain evidence of being a subaqueous deposit; there the 1st stage is so, but it is covered by two reef stages, and these again by the 5th stage. The 5th...
Page 385 - ... lead, and many others ; a slight trace of copper in the Bath waters being exceptional. Nevertheless, there is a strong presumption that there exists some relationship between the action of thermal waters and the filling of rents with metallic ores. The component elements of these ores may, in the first instance, rise from great depths in a state of sublimation or of solution in intensely heated water, and may then be precipitated on the walls of a fissure as soon as the ascending vapors or fluids...
Page 13 - formation," which I have used in the above explanation, expresses in geology any assemblage of rocks which have some character in common, whether of origin, age, or composition.