| 单词 | denudation |
| 例句 | To say that any complete denudation of the writer occurs in the successful work is, according to me, a romantic exaggeration. Flannery O’Connor’s Revelatory Honesty 2001-01-22T05:00:00Z Weathering intensity data further indicate that soil chemical denudation rates increase proportionally with erosion rates. [Report] Rapid Soil Production and Weathering in the Southern Alps, New Zealand 2014-02-06T19:26:30.431Z Physical weathering must be specified every time as well as chemical weathering and, in the first case, terms such as “mechanical erosion” or “physical denudation” would be preferable. [Technical Comment] Comment on “Intensifying Weathering and Land Use in Iron Age Central Africa” 2012-08-30T18:25:26.920Z And if there is a desire to make amends for the drought, we have what we call a flood and blame it on the weather instead of on our precipitous denudation of the watersheds. Reading the Weather 2012-04-19T02:00:27.487Z It is also in this respect preferable to denudation with a brush. Directions for Collecting and Preserving Insects 2012-03-28T02:00:31.483Z It is probable that the extent of this process of denudation determines the severity or mildness of the attack.... A System of Practical Medicine by American Authors, Vol. I Volume 1: Pathology and General Diseases 2012-03-17T02:00:54.097Z Because of their less resistance to denudation, these rocks have permitted a broadening of the valley in this part of the course. Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 8 "Hudson River" to "Hurstmonceaux" 2012-02-24T03:00:27.173Z On his accession she confiscated a full half of his episcopal property, and was constantly insisting on further denudations, including Ely House, Holborn. Highways and Byways in Cambridge and Ely 2012-02-03T03:00:22.657Z Scattered here and there over the chalk are small outlying remnants which remain to show that the two Tertiary areas were once continuous, before the agencies of denudation had removed them from the chalk. Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 8 "Haller, Albrecht" to "Harmonium" 2012-01-02T03:00:22.443Z In some of her largest valleys the floods have resulted primarily from the denudation of the mountains and the destruction of the woodland and forest cover on the watersheds of the rivers. Our National Defense: The Patriotism of Peace 2011-12-14T03:00:16.577Z The climate has been affected by the change; rain falls less frequently but with greater violence, and the process of denudation is accelerated. Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 4 "Grasshopper" to "Greek Language" 2011-11-28T03:00:19.517Z At the top of the canyon is 1000 ft. of limestone with gypsum and chert, noted for the pinnacles and towers which denudation has developed. Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 "Gordon, Lord George" to "Grasses" 2011-11-13T03:00:13.177Z Oftenest of all, denudation has come into play, and vast masses of fossiliferous rock have been entirely worn away, as is demonstrated by the abundant unconformabilities in the structure of the earth’s crust. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The river having been closed with ice within the last two days, we crossed it this afternoon to visit the two pyramidal monuments of geological denudation which mark the limestone range of the opposite shore. Scenes and Andventures in the Semi-Alpine Region of the Ozark Mountains of Missouri and Arkansas 2011-07-10T02:00:18.883Z The preservation of the forests is primarily for the protection of the water supply, and this is not possible through the denudation of the lands. Proceedings of the Second National Conservation Congress at Saint Paul, September 5-8, 1910 2011-05-07T02:00:26.100Z These rocks were upraised probably in part into lofty mountains, and then worn down by erosion nearly to sea-level, thus forming what is termed a peneplain, or a plain of subaerial denudation. North America 2011-05-05T02:00:20.027Z Down by the river are the folded rocks of an ancient mountain system, formed before vertebrate life appeared on the earth, then worn to an almost level condition through untold ages of slow denudation. Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 "Gordon, Lord George" to "Grasses" 2011-11-13T03:00:13.177Z The study of certain ancient volcanoes, the roots of which have been exposed by long denudation, has shown an absence of any visible trace of their having availed themselves of fractures in the crust. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The portion of an anticline which has been removed by denudation is the “aerial arch,” dotted in fig. Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" 2011-04-03T02:00:20.883Z The peculiarity is due to the hard carboniferous limestone, which forms its periphery, having better resisted denudation than the softer matrix of the coal measures embraced by it. No Quarter! 2011-03-26T02:00:16.330Z Fissures filled in this manner from below, as denudation progresses, become exposed at the surface and reconcentration through the influence of disintegration and decay, and of solution and redeposition by descending water takes place. North America 2011-05-05T02:00:20.027Z By them, undoubtedly, was made the first breach over its top, thus commencing that slow but sure denudation which finally reached the rock below. The Falls of Niagara and Other Famous Cataracts 2011-03-26T02:00:15.717Z It abounds in gaps, some of which have been caused by the destruction of strata owing to metamorphism, denudation or otherwise, others by original non-deposition, as above explained. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z For example, in many coal regions the deposits have been conserved in some districts in the synclines or “basins,” while they have been removed by denudation from the uplifted anticlines in others. Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5 "Fleury, Claude" to "Foraker" 2011-04-03T02:00:20.883Z The denudation and destruction of the granites gave rise to the Ladoga schists and various deposits of the same period, which were subsequently strongly folded. Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 4 "Finland" to "Fleury, Andre" 2011-03-20T02:00:30.697Z The whitish yellow limestone forms low, flat-topped hills, now isolated from each other by natural denudation, which has removed the intervening rock. Dragons of the Air An Account of Extinct Flying Reptiles 2011-02-20T03:00:13.067Z And, second, we must not forget the intense denudation which they have experienced, so that miles and miles of strata which once existed have been swept away, and their materials built up into new formations. Geology 2011-02-20T03:00:12.660Z But even the youngest existing chain has suffered so greatly from denudation that the aspect which it presented at the time of its uplift can only be dimly perceived. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Here the terraced features of the volcanic plateau, produced by the denudation of the successive flows is well displayed. Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 8 "Dubner" to "Dyeing" 2010-12-26T03:00:17.840Z New masses of granites protruded next from underneath, and the Bothnian deposits underwent foldings in their turn, while denudation was again at work on a grand scale. Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 4 "Finland" to "Fleury, Andre" 2011-03-20T02:00:30.697Z The earliest known sediments must have been deep in the zones of shearing and rock flowage before the first pre-Cambrian denudation. Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 4 "Aram, Eugene" to "Arcueil" What have been the general effects produced by denudation on the face of the land? Geology 2011-02-20T03:00:12.660Z In the general subaerial denudation of a country, innumerable minor features are worked out as the structure of the rocks controls the operations of the eroding agents. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Over both sandstone and granite great sheets of lava have been poured, and these, protecting the softer beds beneath from further denudation, now stand up as the high plateaus and hills called harra. Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 3 "Apollodorus" to "Aral" There is some variation in the thickness of the strata in different parts of the Island, and the amount of the Upper strata, which has been removed by denudation, varies considerably. The Geological Story of the Isle of Wight Its general elevation is less than that of the S�o Francisco region, owing to the slope of the plateau surface toward the Amazon depression and to denudation. Encyclopaedia Britannica, 11th Edition, Volume 4, Slice 4 "Bradford, William" to "Brequigny, Louis" How is the waste of land by denudation compensated? Geology 2011-02-20T03:00:12.660Z Such a chain may be the result of one colossal disturbance; but those of high geological antiquity usually furnish proofs of successive uplifts with more or less intervening denudation. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Subsequent denudation has removed the sedimentary covering and exposed the igneous core. Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 5 "Cat" to "Celt" Worn down by denudation the edges are now exposed in lines running south-west to north-east, while the strata dip south-east under the edges of the more recent strata. The Geological Story of the Isle of Wight But is it reasonable to expect, after the waste caused by denudation, that calcareous masses, gradually upheaved in an open sea, should retain such vast thicknesses? Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology It can be proved that strata miles in thickness have been removed bodily from the surface of our own country by the seemingly feeble agents of denudation. Geology 2011-02-20T03:00:12.660Z The chain thus successively upheaved has been continuously exposed to denudation and has consequently lost much of its original height. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The rocks underlying it have been subjected to successive foldings and crumplings by forces acting chiefly from the direction of the Atlantic Ocean, with alternating prolonged periods of waste and denudation. Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 2 "Camorra" to "Cape Colony" It is probable that during much of the period the British Isles were dry land, and that great denudation of the land took place. The Geological Story of the Isle of Wight Such an inference is perfectly in harmony with views which the grand scale of denudation, everywhere observable in the older rocks, has led geologists to adopt in reference to upward movements. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology It is true that this denudation has progressed at a rate with which nothing of a like character in the history of the world is comparable. The Greater Republic A History of the United States But from the structure of mountains, as laid open by prolonged denudation, it is possible to form a vivid conception of the nature and effects of these most stupendous of all geological revolutions. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z This was only the prelude to a set of geological illustrations, including the terraces formed by ancient river-beds, denudation, and half a dozen other ations. From Sea to Sea Letters of Travel Clearly, the gravel was formed before denudation had cut out the great gap between the central and southern downs of the Island. The Geological Story of the Isle of Wight These opinions were both illogical and inconsistent, because deposition and denudation are parts of the same process, and what is true of the one must be true of the other. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology Cambrian rocks previously described are all such as would result from deposition, in comparatively shallow seas, of the products of degradation of land surfaces by the ordinary agents of denudation. Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 1 "Calhoun" to "Camoens" On this broken-up surface the various agents of denudation have been ceaselessly engaged since it emerged from the sea. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The rate of denudation in exposed positions is exceedingly rapid; while spots sheltered from the sand blast suffer a minimum of erosion, as shown by the preservation of ancient inscriptions. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 1 "Edwardes" to "Ehrenbreitstein" In the course of denudation the bottom of a river valley often becomes the highest part of a district. The Geological Story of the Isle of Wight Extensive denudation must also combine with upheaval before they can be displayed at the surface throughout wide areas. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology Evidently the denudation has been enormous, while the inevitable outcome is subtle balanced beauty. My First Summer in the Sierra Similar volcanic scenery has been produced in western Europe by the action of denudation in dissecting the flat Tertiary lavas of Scotland, the Faeroe Isles and Iceland. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z This surface, or “peneplain,” was probably the result of denudation working away the beds almost to sea-level. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 4 "Coquelin" to "Costume" When, as in the south side of our central downs, the strata are sharply cut away by denudation, we call this an escarpment. The Geological Story of the Isle of Wight In this small fraction of land already explored, and still very imperfectly known, we are required to find a set of strata, originally of limited extent, and probably much lessened by subsequent denudation. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology The mountains of one period have disappeared by denudation or subsidence, while the mountains of the succeeding period have been rising from beneath the waves. Island Life Or the Phenomena and Causes of Insular Faunas and Floras Sometimes these irregularities have been produced by folds of the terrestrial crust, sometimes by faults, sometimes by the irregularities on the surface of an uplifted platform of deposition or of denudation. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Then the levels of all the upper lakes were higher than they are to-day, those levels having been considerably lowered through the white man's denudations of the forests in the Basin of the Great Lakes. Niagara An Aboriginal Center of Trade Especially well can this be seen in flints which have lain some time in a gravel bed formed of flints worn out of the chalk by denudation. The Geological Story of the Isle of Wight The single long and deep opening into the crater is a feature common to all those remnants of ancient volcanoes, the central portions of which have been removed, and is probably connected with aqueous denudation. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology A considerable but unknown amount of denudation is effected by the waves of the ocean eating away coast lines. Island Life Or the Phenomena and Causes of Insular Faunas and Floras Eminences which have been isolated by denudation from the main mass of the formations of which they originally formed part are known as “outliers” or “hills of circumdenudation.” Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Both, it has been said, are monuments of denudation only, "lofty because they have suffered less wear than their neighbours." In the Border Country Its presence at the surface is due to denudation of the masses by which it was originally overspread. Volcanoes: Past and Present The central portions of the dome have since been removed by engulfment, or denudation, or by both these causes. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology It is now generally admitted that sub-a�rial denudation is a much more powerful agent in lowering and modifying the surface of a country than was formerly supposed. Island Life Or the Phenomena and Causes of Insular Faunas and Floras Examples of ancient and much decayed tablelands formed by the denudation of much disturbed rocks are furnished by the Highlands of Scotland and of Norway. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Towards the south and east the volcanic pile is overlaid by Carboniferous strata, thus indicating a prolonged interval of denudation. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" True, the river pierced it, the denudation of solid sandstone cliffs, a thousand feet in height, betokening the untiring energy of the eroding currents of centuries agone. The Mystery of Witch-Face Mountain and Other Stories In this case there is often an elliptical cavity at the summit, due partly to the fracture of the upraised rocks, but still more to aqueous denudation, as they rose out of the sea. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology The amount of average denudation, however, is not a matter of opinion but of measurement; and its consequences can in no way be evaded. Island Life Or the Phenomena and Causes of Insular Faunas and Floras This is more especially the case in respect of the wide domain of denudation. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The oldest strata, which are of Upper Silurian age, form inliers that have been exposed by the denudation of the younger palaeozoic rocks. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" In many places it represents the land planed down by wave action to a plain of marine denudation, where the waves have battered down the cliffs and dragged the material under water. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 2 "Constantine Pavlovich" to "Convention" The fact also of a very gradual and insensible elevation of land may explain many geological movements of denudation, on a grand scale. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology As these two areas are as 1 to 19, it follows that deposition, as measured by maximum thickness, goes on at least nineteen times as fast as denudation—probably very much faster. Island Life Or the Phenomena and Causes of Insular Faunas and Floras A method of making use of these records for estimating the rate of denudation of the land has been devised. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z The amount of sediment carried through the mouth of a great river furnishes a clew to the rate of denudation of the area drained by that river. A History of Science, Volume 5(of 5) Aspects Of Recent Science These masses, there can be no doubt, are remains of superincumbent beds of hard rock that have been removed by denudation, leaving but a few fragments behind. The Broom-Squire The extent of this denudation, as estimated by the number of cubic feet of matter removed annually, will be again spoken of in chapter 22. Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology This large proportion of carbonate of lime implies some other source of this mineral, and it is probably to be found in the excessively fine mud produced by the decomposition and denudation of coral reefs. Island Life Or the Phenomena and Causes of Insular Faunas and Floras On the one hand, it includes the oldest and most deep-seated extravasations of that magma, which have been brought to light by ruptures and upheavals of the crust and prolonged denudation. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z Dartmoor is a mass of granite that was intruded into the Culm and Devonian strata in post-Carboniferous times and subsequently exposed by denudation. Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 3 "Destructors" to "Diameter" When the exposed land consists of several unlike kinds of sedimentary strata, or igneous rocks, or both, denudation produces changes proportionably more heterogeneous. Essays: Scientific, Political, & Speculative, Vol. I At Little Rock, in the valley of the Arkansas, vestiges of art have recently been found in similar beds of denudation, at considerable depths below the surface of the wooded plains. Incentives to the Study of the Ancient Period of American History An address, delivered before the New York Historical Society, at its forty-second anniversary, 17th November 1846 The above estimate indicates a far higher rate; and this follows from the well-ascertained fact, that the area of deposition is many times smaller than the area of denudation. Island Life Or the Phenomena and Causes of Insular Faunas and Floras The trade winds, which are now peaceful agents of commerce, would then be perpetual hurricanes, and all the denudation agents of the geologist would be in a state of feverish activity. Pioneers of Science But if the mountain chains are due to compression, the present valleys are mainly the result of denudation. The Beauties of Nature and the Wonders of the World We Live In The denudation of the hills led to terrible floods along the rivers. The New Nation As a monument of denudation, this chasm is an example of downward erosion by sand-bearing water. The Book of the National Parks Occasionally it is found as high as two thousand feet above the sea, in hollows or hill-sides, where it seems to have been protected from denudation. Island Life Or the Phenomena and Causes of Insular Faunas and Floras Consider for a moment the denudation import of the tides: how does the existence of tidal rise and fall affect the geological problem? Pioneers of Science In the Alps then the present configuration of the surface is mainly the result of denudation. The Beauties of Nature and the Wonders of the World We Live In Norway and Sweden have been shipping timber for some centuries, and yet seem to need no laws to restrain the denudation of their hills; certainly not to encourage rainfall. Lippincott's Magazine, December 1878 The denudations that left our stark Cornish coasts as we know them now for the most part occurred in times that are dim and legendary. The Cornwall Coast The consequent effect of denudation that lags behind alteration is to raise slowly the concentrated metals toward the surface, and thus subject them to renewed attack and repeated migration. Principles of Mining Valuation, Organization and Administration Another five hours, and the water would come tearing and driving over the country, applying its furious waves and currents to the work of denudation, which would proceed apace. Pioneers of Science Moreover, the denudation by aerial action, by glaciers, frosts, and rivers has removed hundreds, or rather thousands, of feet of strata. The Beauties of Nature and the Wonders of the World We Live In A flame is extinguished and dies, a mountain is ultimately ground into sand by the slow influence of denudation, a planet or a sun may lose its identity by encounter with other bodies. Life and Matter A Criticism of Professor Haeckel's 'Riddle of the Universe' The destruction of the south wall may have occurred much later through some great eruptive paroxysm, but more probably, as Professor Mercalli suggests, through early marine erosion and subsequent subaerial denudation. A Study of Recent Earthquakes Flat, arid regions present the other extreme, for denudation is much slower, and conditions are most perfect for deep penetration of oxidizing agencies, and the consequent alteration and concentration of the metals. Principles of Mining Valuation, Organization and Administration The anterior flap is oval, twice as long as posterior, and the patella is brought up after denudation against end of femur. A Manual of the Operations of Surgery For the Use of Senior Students, House Surgeons, and Junior Practitioners The denudation of that range was allowed to go on for an inordinate time with disastrous results to the plains below. The Panjab, North-West Frontier Province, and Kashmir Not only are the walls in a very poor condition, but also the floors show, from the absence of dry soil upon them, that the whole ruin has suffered greatly from the same denudation. Archeological Expedition to Arizona in 1895 Seventeenth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1895-1896, Government Printing Office, Washington, 1898, pages 519-744 Along the southern edge of the Garo and Khasi hills, great sand-fans spread over the fields, and the exposure of the hillsides formerly protected by forest left free scope for future denudation. A Study of Recent Earthquakes In the “Mishna” it says, “It is permitted on the Sabbath to do all that is necessary to perform circumcision, excision, denudation, and suction.” History of Circumcision from the Earliest Times to the Present Moral and Physical Reasons for its Performance The thickness of the deposits gives a measure for the colossal scale of the denudations by which this immense accumulation was reduced to its present level. The Atlantic Monthly, Volume 18, No. 106, August, 1866 Hence, under ordinary circumstances, I should infer that for a cliff 500 feet in height, a denudation of one inch per century for the whole length would be a sufficient allowance. On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life. (2nd edition) They represent in every possible detail, and in each successive stage of denudation, the organs of sense and reproduction; the muscular, the vascular, the nervous, and the bony system. Curiosities of Literature, Vol. 1 This is due to the greater indestructibility of the quartz pebbles, and the weathering away, or denudation, of the sandstone face. The American Architect and Building News, Vol. 27, Jan-Mar, 1890 This denudation has had an undoubted effect upon the rainfall, and has served to change the climatic conditions in these regions. Mexico Its Ancient and Modern Civilisation, History, Political Conditions, Topography, Natural Resources, Industries and General Development Of course, under the heavy tropical rains this denudation is still going on, though in a greatly modified form. The Atlantic Monthly, Volume 18, No. 106, August, 1866 But this time, it seems to me, we have consciously and responsibly to carry ourselves through the winter-period, the period of death and denudation: that is, some of us have, some nation even must. Fantasia of the Unconscious He, too, was voyaging towards some melancholy autumnal maturity, some sorrowful denudation of youth, that left him pitiful to her impotently aching heart. Phantom Wires A Novel It has been my lot at various times to witness the institution known as "home" in a state of denudation, as my scientific friends would call it. Disturbed Ireland Being the Letters Written During the Winter of 1880-81. It would be cruel, in this terrible denudation, to deny him the consolation of his national gift, that "American humour" of which of late years we have heard so much. Hawthorne (English Men of Letters Series) In one word, all these hills were formerly part of a continuous formation, and owe their present outline and their isolated position to a colossal denudation. The Atlantic Monthly, Volume 18, No. 106, August, 1866 In Tokay the vines are never trellised, they are disposed irregularly, not even in rows—the better to escape the denudation of their roots by rain. Round About the Carpathians A typical clearing about a mound of Dipodomys s. spectabilis, showing the autumnal denudation of the mound and surrounding areas. Life History of the Kangaroo Rat Subsequent denudation has laid bare the part of the mountain now exposed along the river. The Hudson Three Centuries of History, Romance and Invention They differ from the terrestrial phenomena so designated in the fact that the surface indications of these are destroyed by denudation or masked by deposits of subsequent date. The Moon A Full Description and Map of its Principal Physical Features The longitudinal trend of these hills is to be ascribed to the direction of the current which caused the denudation, while their level summits are due to the regularity of the stratification. The Atlantic Monthly, Volume 18, No. 106, August, 1866 An individual given to such wanton denudation would simply be at a disadvantage with his decently covered fellows, would fall behind in the race of life, and perish with his kind. Certain Personal Matters Each year, according to the tale of the old settlers, the rivers of the prairies have been becoming wider by denudation, so that each flood tends to be less. The Romantic Settlement of Lord Selkirk's Colonists The Pioneers of Manitoba The material of which sediments are formed is derived, by the various processes of denudation, from the rocks of older land surfaces. Cave Regions of the Ozarks and Black Hills Long lines of hills of denudation are in the distance, all directed to the Lake. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume II (of 2), 1869-1873 Continued By A Narrative Of His Last Moments And Sufferings, Obtained From His Faithful Servants Chuma And Susi Such an extensive oceanic denudation must have carried away not only the gigantic glacial moraine here assumed to have closed the mouth of the Amazonian basin, but the very ground on which it stood. The Atlantic Monthly, Volume 18, No. 106, August, 1866 These plains are swamps at times, and they are flanked by ridges of denudation some 200 or 300 feet above them, and covered with trees. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume I (of 2), 1866-1868 The total mass of the sediments formed since denudation began may be ascertained with comparative accuracy by a study of the chemical composition of the waters of the ocean. The Birth-Time of the World and Other Scientific Essays When the exposed land consists of several unlike formations, sedimentary and igneous, the denudation produces changes proportionably more heterogeneous. Essays on Education and Kindred Subjects Everyman's Library The next ordeal through which the Republicans had to pass began with the denudation of the two States. In the Shadow of Death You have no rainfall to bother you, no local streams, no complex denudation: the Nile does all, and the Nile does everything. Science in Arcady The lines of denudation are continued, one range rising behind another as far as the eye can reach to the north and east of Liemba, and probably the slope continues away down to Tanganyika. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume I (of 2), 1866-1868 If the land is, on the whole, now sinking relatively to the ocean level, the denudation area tends, as we have seen, to move inwards. The Birth-Time of the World and Other Scientific Essays Because to me the clearings spoke of naught but denudation, I thought that to those whose sturdy arms and obedient axes had made them they could tell no other story. Talks To Teachers On Psychology; And To Students On Some Of Life's Ideals I have already referred to the rapid denudation which is going on in these islands, and to the extent to which they have been denuded within comparatively recent times. Young Folks' Library, Volume XI (of 20) Wonders of Earth, Sea and Sky No long Sacramento Valley, stretching away to the south and west of the quartzite upheavals, has here retained and preserved the spoils of those long ages of attrition and denudation. The Atlantic Monthly, Volume 13, No. 79, May, 1864 Here we could see westwards and northwards the long lines of hills of denudation in Nsama's country, which till lately was densely peopled. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume I (of 2), 1866-1868 Geologists have estimated the age of the Earth since denudation began, by measurements of the integral effects of denudation. The Birth-Time of the World and Other Scientific Essays The entire area has been subjected to sub-aerial denudation on a gigantic scale, which explains the occurrence of the basalt as the caps of isolated hills. Rambles and Recollections of an Indian Official But the chances against this are enormous, because denudation is always going on, and the rocks we now find at the earth's surface are only a small fragment of those which were originally laid down. Darwinism (1889) The Chalk has invariably suffered much erosion and denudation before the lowest Tertiary strata were deposited upon it. The Ancient Life History of the Earth A Comprehensive Outline of the Principles and Leading Facts of Palæontological Science In going westwards on the upland the country is level and covered with scraggy forest as usual, long lines of low hills or rather ridges of denudation run. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume I (of 2), 1866-1868 Whether the movements attending mountain elevation and denudation are a connected and integral part of those wide geographical changes which result in submergence and elevation of large continental areas, is an obscure and complex question. The Birth-Time of the World and Other Scientific Essays The Indian Government long remained blind to the importance of the duty of saving the country from denudation. Rambles and Recollections of an Indian Official Nowhere are the evidences of this denudation more apparent than in North and South America, where granitic or metamorphic rocks cover an area hardly less than that of all Europe. Darwinism (1889) The Devonian might have been deposited upon the Silurian, and then the whole might have been elevated above the sea, and subjected to an amount of denudation sufficient to remove the Devonian strata entirely. The Ancient Life History of the Earth A Comprehensive Outline of the Principles and Leading Facts of Palæontological Science The valleys of denudation enclosed by these hill ranges guide the streams towards Liemba or the four rivers which flow into it. The Last Journals of David Livingstone, in Central Africa, from 1865 to His Death, Volume I (of 2), 1866-1868 What we see today in the Alps is but a residue spared by denudation. The Birth-Time of the World and Other Scientific Essays The desolation of the ravines of the rivers of Central India and Bundēlkhand offers a very striking spectacle, presenting to the geologist a signal example of the effects of sub-aerial denudation. Rambles and Recollections of an Indian Official Here and there, as a result of denudation, a portion of one of them appears capping a hilltop. Q. E. D., or New Light on the Doctrine of Creation Its geographical extent, though uncertain, owing to the enormous denudation to which it has been subjected, is nevertheless great, since it extends from Dorsetshire to France, and occurs also in North Germany. The Ancient Life History of the Earth A Comprehensive Outline of the Principles and Leading Facts of Palæontological Science In the troughs of the foldings thus formed the coal-measures rest, those portions which had been thrown up as anticlines having suffered loss by denudation. The Story of a Piece of Coal What It Is, Whence It Comes, and Whither It Goes Ocean, amount of rock salt in, 50; cause of black colour of, 55; estimated mass of sediments in, 48; increase of bulk due to solvent denudation, 52; its saltness due to denudation, 41. The Birth-Time of the World and Other Scientific Essays The village is picturesque and well placed, and the local "lion"—"Great upon little," an effect of denudation, is well known. Seaward Sussex The South Downs from End to End His subject leads him to consider much at large the denudation of mountains, which has caused and is causing such calamitous mischief in Italy and the south of France. What I Remember, Volume 2 And a hand pointed to the uncovered bed, and to the empty table and empty clothes-racks—the careful denudation of unoccupied rooms. The Inferno Even as it is, it has at a former epoch suffered great denudation, if certain detached basins should be considered as indicating its former extent. The Story of a Piece of Coal What It Is, Whence It Comes, and Whither It Goes Keeping the figures to round numbers we find that this amount of sodium involves the denudation of about 80 x 1016 tonnes of average igneous rock to 53 x 1016 tonnes of average sediment. The Birth-Time of the World and Other Scientific Essays The surface is scooped out into irregular basins and sharp projecting pinnacles and covered in all directions with mud, resulting from the denudation. The Story of the Philippines and Our New Possessions, Including the Ladrones, Hawaii, Cuba and Porto Rico The Eldorado of the Orient In the state of uncertainty, embarrassment, and denudation in which you have placed yourselves, you have no strength, I can feel, I can see. A Popular History of France from the Earliest Times, Volume 6 At one time supposed to have been brought to their present position by glacial action, they are now said to be, and undoubtedly are, the result of denudation. Wanderings in Wessex An Exploration of the Southern Realm from Itchen to Otter Only thus can we gain time, at all sufficient to explain the truly astonishing amount of denudation, which these great, though comparatively with most other ranges recent, mountains have suffered. The Voyage of the Beagle The effects of purely solvent denudation are less easily traced, but, very probably, they have been of not less importance. The Birth-Time of the World and Other Scientific Essays Dupuytren speaks of denudation of the skin from a burn, with the subsequent development of vicarious catamenia from the seat of the injury. Anomalies and Curiosities of Medicine Such denudation must be made impossible; our fleet so augmented and strengthened as to provide impregnably at all times for home defence no less than for foreign necessities. Biographical Study of A.W. Kinglake This is an age in which scientific atheism, having divested itself of the habiliments that most adorn and dignify humanity, walks abroad in shameless denudation. History of the Warfare of Science with Theology in Christendom How much denudation and degradation has been effected we have no means of determining, the porous, crumbling rocks being ill adapted for the reception and preservation of glacial inscriptions. Steep Trails California, Utah, Nevada, Washington, Oregon, the Grand Canyon There may, indeed, have been some primitive sodium dissolved by a more rapid denudation while the Earth's surface was still falling in temperature. The Birth-Time of the World and Other Scientific Essays Its variations may be due equally to natural denudation of a stratum once of uniform depth, or to the artificial heaping up of a mound by later builders. The Project Gutenberg Encyclopedia Volume 1 of 28 Such rapid changes from complete saturation to sudden heat are trying to the hardest rocks, and at Hardraw, close at hand, there is a still more palpable process of denudation in active operation. Yorkshire The rapidity of this melting of the vast snow-beds and glaciers of the Alps was inconceivable, and the effect of the sudden denudation upon the mountains themselves was ghastly. The Second Deluge As the floor of valleys is raised by the denudation and washing down of the mountains, what is average will rise at the expense of what is great. Amiel's Journal These great events are of a rhythmic character; the crust, as it were, pulsating under the combined influences of sedimentation and denudation. The Birth-Time of the World and Other Scientific Essays It appears to approximate in time to the similar earth movement and denudation at the close of the palaeozoic period in Europe. The Project Gutenberg Encyclopedia Volume 1 of 28 No part of this range as far as I could see is deeply sculptured, though the general denudation of the country must have been enormous as the gravel-beds show. Travels in Alaska But as the production of the fissures might have occupied perhaps millions of years, a considerable amount of atmospheric denudation would result, however slowly it acted. Is Mars habitable? A critical examination of Professor Percival Lowell's book "Mars and its canals," with an alternative explanation But mercy! what strippings, what tearing off of histrionic robes, and private vanities! what denudations to the bone, before the surly Ferryman will admit you to set a foot within his battered lighter! The Works of Charles and Mary Lamb — Volume 2 Elia and The Last Essays of Elia However this may be, the greater part of mechanical denudation during geological time has been done on the mountain ranges. The Birth-Time of the World and Other Scientific Essays Along the coastal margins they underlie the newer formations and appear in the deep valleys and kloofs wherever denudation has laid them bare. The Project Gutenberg Encyclopedia Volume 1 of 28 The greatest discovery was in methods of denudation displayed beneath the glacier. Travels in Alaska The Upper Rhine flows in one of these great valleys of subsidence for about 180 miles, from Mulhausen to Frankfort, in a generally straight line, though modified by denudation. Is Mars habitable? A critical examination of Professor Percival Lowell's book "Mars and its canals," with an alternative explanation The destruction of rocks—“denudation” as it is called—in the district round Malvern, is, I am told, provably enormous. Town Geology These causes of local mobility have been in operation, shifting somewhat from place to place, and defined geographically by the continental masses undergoing denudation, since the earliest times. The Birth-Time of the World and Other Scientific Essays With regard to the older igneous rocks, the enormous amount they have suffered from denudation is a prominent feature. The Project Gutenberg Encyclopedia Volume 1 of 28 We are told "the present rate of denudation of a continent is known with considerable accuracy from careful measurements of the quantity of solid matter carried down by rivers." The Faith of the Millions (2nd series) We went on again, the track now really dangerous from denudation and slipperiness. The Hawaiian Archipelago They afford evidence at many points of repeated denudation and redeposition, and may be the monuments of a long series of ages. The Antiquity of Man The appearance of these materials at the surface indicates the removal by denudation and the extreme metamorphism of much sedimentary deposit. The Birth-Time of the World and Other Scientific Essays Similar results have been observed in the plain of Alsace, in consequence of the denudation of several of the crests of the Vosges. The Earth as Modified by Human Action I am beginning to suspect that present distribution is an affair rather of denudation than migration. Life and Letters of Thomas Henry Huxley — Volume 3 The denudation of the land was upon a grand scale. A Tramp Abroad — Volume 06 The parallel shelves, therefore, have not been caused by denudation, but by the deposition of detritus, precisely similar to that which is dispersed in smaller quantities over the declivities of the hills above. The Antiquity of Man There was then fresh disturbance and upheaval followed by denudation, and these mountains, in turn, became worn out and depressed beneath the ocean so that Upper Greensand rocks were laid down unconforrnably on all beneath. The Birth-Time of the World and Other Scientific Essays The Catskills are residual mountains, or what Agassiz calls "denudation mountains." Time and Change Within certain limits accumulation in one place represents denudation elsewhere. Caesar's Column The freest possible use of forest pasture land is permitted, but under such regulations as to prevent injury to the forests and the denudation of the land by overgrazing. Community Civics and Rural Life These changes were accompanied by some denudation followed by a grand submergence of several hundred feet, probably brought about slowly, and when floating ice aided in transporting erratic blocks from great distances. The Antiquity of Man We must imagine almost the whole of these superimposed folds now removed from the central regions of the Alps by denudation, The Birth-Time of the World and Other Scientific Essays The second is a stripping off of extraneous images and a denudation of the heart, so that a man may be free from images, and attachments to every creature. Light, Life, and Love : selections from the German mystics of the middle ages The unpastoral reader may be informed that speed and completeness of denudation are the grand desiderata in shearing; the employer thinks principally of the latter, the shearer principally of the former. Shearing in the Riverina As the average elevation of the lands of the globe is reckoned at 2411 feet, this result would occur in nine or ten million years, if the present rate of denudation should remain unchanged. The Elements of Geology It will be observed that the gravel Number 4 is obliquely stratified, and that its surface had undergone denudation before the white sandy loam Number 3 was superimposed. The Antiquity of Man We estimate by chemical examination of igneous and sedimentary rocks the amount of sodium which has been supplied to the ocean per ton of sediment produced by denudation. The Birth-Time of the World and Other Scientific Essays In the course of such changes many of the existing sedimentary strata would suffer greatly by denudation, others might assume a metamorphic structure, or become melted down into Plutonic and volcanic rocks. The Student's Elements of Geology First, let it be said, that certain alluvial gold is unquestionably derived from the denudation of quartz lodes. Getting Gold: a practical treatise for prospectors, miners and students Immense bodies of molten rock were intruded into the crust as it suffered deformation, and these appear in the large areas of granite which the later denudation of the range has brought to light. The Elements of Geology After this denudation, which may have accompanied the emergence of the land, the country was inhabited by the primitive people who fashioned the flint tools. The Antiquity of Man The order of magnitude of these results cannot be shaken unless on the assumption that there is something entirely misleading in the existing rate of solvent denudation. The Birth-Time of the World and Other Scientific Essays In order to bring them into view, or within reach of the miner, a greater amount of upheaval and denudation must take place in proportion as they have lain deeper when first formed and filled. The Student's Elements of Geology A circle thus formed, an apex would be the natural result of the denudation and decay of the upper surface which would produce a cone. Cyprus, as I Saw It in 1879 What remains of these rock systems after the denudation of all later geologic ages is enormous. The Elements of Geology The old deserted branch is separated from the new or present channel of the Thames, by a mass of London Clay which has escaped denudation. The Antiquity of Man There may be some convergence in the rate of solvent denudation, but—as I think on the evidence—in our time unimportant. The Birth-Time of the World and Other Scientific Essays Hence it seems that the Uralian quartz veins, containing gold and platinum, were not formed, or certainly not exposed to aqueous denudation, during the Permian era. The Student's Elements of Geology Concluding remarks on the denudation and elevation of the Portillo line.— Geological Observations on South America As rivers pass their prime, as denudation lowers the relief of the region, less waste and finer is washed over the gentler slopes of the lowering hills. The Elements of Geology The materials of this uppermost deposit are arranged as if they had been the result of land floods, taking place after the formations 2 and 3 had been raised, or had become exposed to denudation. The Antiquity of Man The mere extent of the land surface does not, within limits, affect the question of the rate of denudation. The Birth-Time of the World and Other Scientific Essays Land, balance of dry, how preserved. — has been raised, not the sea lowered. —, mean height of, above the sea. —, rise of, in Sweden. —, rise and fall of, affecting denudation. The Student's Elements of Geology These little pebbles have probably been derived from the denudation of a more regular bed of gravel, capping the old tertiary sandstone plateau of the Rio Negro. Geological Observations on South America The same lesson is taught as plainly by the amount of denudation which the lands suffered during the era. The Elements of Geology However, it resists denudation in a remarkable manner, and in China it often stands up in vertical walls hundreds of feet in height. The Antiquity of Man From what has been reviewed above it is evident that the sodium in the ocean is an index of the total activity of denudation integrated over geological time. The Birth-Time of the World and Other Scientific Essays Nova Scotia coal-measures. — coal, reptiles and shells in. —, folding and denudation of beds in. The Student's Elements of Geology So also the denudation and the gravel-covering of the 90 feet plain must have taken place subsequently to the elevation of the 250 feet plain, on which recent shells are also strewed. Geological Observations on South America Assuming that the Triassic deformation went on more rapidly than denudation, what was its effect on the topography of the time? The Elements of Geology After this subsidence, the re-elevation and partial denudation of the Cretaceous and glacial beds took place during a general upward movement, like that now experienced in parts of Sweden and Norway. The Antiquity of Man The mountains have again been worn down into the ocean by denudation and again younger mountains built out of their redeposited materials. The Birth-Time of the World and Other Scientific Essays Upheaval of land more than counteracted by subsidence. —, power of denudation to counteract. The Student's Elements of Geology Concluding remarks on the denudation and elevation of the Portillo line. Geological Observations on South America On the whole, which have worked more rapidly, processes of deformation or of denudation? The Elements of Geology Not a stick of young or old wood was left to mark the boundary of a future clearing, not even an angle to mark the limit of the denudation. Eight Hundred Leagues on the Amazon By measuring radioactive products ages have been found which, while they vary widely among themselves, yet claim to possess accuracy in their superior limits, and exceed those derived from denudation from nine to fourteen times. The Birth-Time of the World and Other Scientific Essays Mississippi, sediment of, used as a test of denudation by rivers. — valley, deposition and denudation in the. The Student's Elements of Geology Owing to the amount of denudation which this chain has suffered, the outline of the gently inclined eastern flank scarcely offers the slightest indication of this synclinal axis. Geological Observations on South America During the later Silurian and the Devonian the area was land and suffered vast denudation. The Elements of Geology Considerable intervals of time appear to have elapsed, judging from the marks of denudation, between the formation of the successive beds, of which this ridge is composed. Volcanic Islands THE subject of denudation is at once one of the most interesting and one of the most complicated with which the geologist has to deal. The Birth-Time of the World and Other Scientific Essays Folding and denudation of Nova Scotia Carboniferous rocks. The Student's Elements of Geology There are no "craters of denudation" at Galapagos. More Letters of Charles Darwin — Volume 2 It is they which uplift and recreate the lands which the agents of denudation are continually destroying; it is they which deepen the ocean bed and thus withdraw its waters from the shores. The Elements of Geology If this hill has had, as is probable, a similar origin, denudation has been here effected on an enormous scale. Volcanic Islands It is often difficult or impossible to appraise the relative efficiency of mechanical and chemical denudation in removing the materials from a certain area. The Birth-Time of the World and Other Scientific Essays Such breccias may have been partly the result of the subaerial waste of an old land-surface which gradually sank down and suffered littoral denudation in proportion as it became submerged. The Student's Elements of Geology I see little of interest except on volcanic action and denudation, and here and there scattered remarks; some of the later chapters are very bald. More Letters of Charles Darwin — Volume 2 Draw a second diagram showing the same block after denudation has worn it down below the center of the upthrown side. The Elements of Geology One of the most striking parts of the book is that in which he deals with the effects of denudation in producing "basal wrecks" or worn down stumps of volcanoes. Volcanic Islands Now while gravitational forces favour sudden shock and violent motions in the hills, the effect of these on solvent and chemical denudation is but small. The Birth-Time of the World and Other Scientific Essays Now, if such a mass should afterwards be divided into separate fragments by denudation, we might still, perhaps, identify the detached portions by their similarity in mineral composition. The Student's Elements of Geology Many of your scattered remarks on denudation have particularly interested me; but I see that you attribute less to sea and more to running water than I have been accustomed to do. More Letters of Charles Darwin — Volume 2 As deposition in the sea corresponds to denudation on the land, we are able to make a general estimate of the rate at which the former process is going on. The Elements of Geology I use it much as a geologist does the word denudation—for an agent, expressing the result of several combined actions. More Letters of Charles Darwin — Volume 1 The area of deposition is much less than that of denudation; probably hardly as much as one twentieth. The Birth-Time of the World and Other Scientific Essays But as the Plutonic rocks originate at some depth in the earth's crust, they can only be rendered accessible to human observation by subsequent upheaval and denudation. The Student's Elements of Geology I think I agree largely with you about denudation—but the rocky-lake-basin theory is the part which interests me at present. More Letters of Charles Darwin — Volume 2 Considering the thickness of their strata, the compression which mountains have undergone accounts fully for their height, with enough to spare for all that has been lost by denudation. The Elements of Geology The circumferential parts would consist of massive species, in a vertical position, with their interstices filled up with detritus; but this would be the part most subject to subsequent denudation and removal. Coral Reefs In the light of this fact the whole work of denudation stands revealed. The Birth-Time of the World and Other Scientific Essays And marine denudation, to be treated of in the next chapter, will help us to understand why that which should be the protruding portion of the faulted rocks is missing at the surface. The Student's Elements of Geology I am more struck with his remarks on denudation than you seem to be. More Letters of Charles Darwin — Volume 2 Either, then, the earth is very young and the agents of denudation have not yet had time to do their work, or they have been opposed successfully by other forces. The Elements of Geology Of the many striking results due to the modern progress of geology there are hardly any more striking than those which relate to denudation. The formation of vegetable mould through the action of worms, with observations on their habits From this the broad facts of the results of denudation admit of determination with considerable accuracy. The Birth-Time of the World and Other Scientific Essays Subaerial denudation would not of itself lessen the area of the land, but would tend to fill up with sediment seas of moderate depth adjoining the coast. The Student's Elements of Geology I was formerly a great believer in the power of the sea in denudation, and this was perhaps natural, as most of my geological work was done near sea-coasts and on islands. More Letters of Charles Darwin — Volume 2 Compared with subaerial denudation, marine abrasion is a comparatively feeble agent. The Elements of Geology In all humid, even moderately humid, countries, worms aid in the work of denudation in several ways. The formation of vegetable mould through the action of worms, with observations on their habits We have seen that solvent denudation removed over 1,600 feet of rock. The Birth-Time of the World and Other Scientific Essays Organic remains also of the older chalk and Lias are met with, showing how great was the denudation of previous formations during the Pliocene period. The Student's Elements of Geology The hostile arguments of the reviewer are geological, and he deals especially with the denudation of the Weald. Life and Letters of Charles Darwin — Volume 2 The texture of the rock of bosses proves that consolidation proceeded slowly and at great depths, and it is only because of vast denudation that they are now exposed to view. The Elements of Geology It was long ago seen that there must have been an immense amount of denudation; but until the successive formations were carefully mapped and measured, no one fully realised how great was the amount. The formation of vegetable mould through the action of worms, with observations on their habits We have here an effect due to the sea salts derived by denudation from the land which has been slowly augmenting during geological time. The Birth-Time of the World and Other Scientific Essays The country where they occur is almost entirely composed of granite and different varieties of granitic schist, with here and there a few patches of Secondary strata, much dislocated, and which have suffered great denudation. The Student's Elements of Geology How little he could ever have grappled with the subject of denudation! Life and Letters of Charles Darwin — Volume 2 They are now exposed to view only because of the profound denudation which has removed the upheaved dome of rocks beneath which they slowly cooled. The Elements of Geology We are now prepared to consider the more direct part which worms take in the denudation of the land. The formation of vegetable mould through the action of worms, with observations on their habits And, again, the conditions of aeration and circulation which largely promote chemical and solvent denudation in the soils are relatively limited and ineffective in the detrital oceanic deposits. The Birth-Time of the World and Other Scientific Essays The upper part of the curves seen in this diagram, Figure 73, and expressed in fainter lines, has been removed by what is called denudation, to be afterwards explained. The Student's Elements of Geology As Lyell has well remarked, the extent and thickness of our sedimentary formations are the result and the measure of the denudation which the earth's crust has elsewhere undergone. The Origin of Species by means of Natural Selection, 6th Edition In moist climates denudation is continually impeded by the mantle of waste and its cover of vegetation, and the land surface can be lowered no faster than the waste is removed by running water. The Elements of Geology After describing this and other analogous cases, Dr. King concludes: "I can have no doubt that worms help greatly in the process of denudation." The formation of vegetable mould through the action of worms, with observations on their habits The entire bulk of the sedimentary rocks, such as sandstones, slates, shales, conglomerates, limestones, etc., and the salt content of the ocean, are due to the combined activity of mechanical and solvent denudation. The Birth-Time of the World and Other Scientific Essays Almost all remains of the terrestrial fauna of the Continent which preceded the period of submergence have been lost; but a few patches of estuarine and fresh- water formations escaped denudation by submergence. The Student's Elements of Geology Scrope in his appreciative reviews of the "Principles" justly pointed out what was the weakest point, the inadequate recognition of sub-aerial as compared with marine denudation. Darwin and Modern Science The horizontal plane of the sea now intersects an old land surface roughened by subaerial denudation. The Elements of Geology E. de Beaumont looks at the vegetable mould which everywhere covers the land as a fixed line, from which the amount of denudation may be measured. The formation of vegetable mould through the action of worms, with observations on their habits A remarkable demonstration of the activity of mechanical denudation is shown by the phenomenon of "earth pillars." The Birth-Time of the World and Other Scientific Essays Time, as I have explained in Chapters 5, 6, and 7, has multiplied the effects of condensation by pressure and cementation, and the modification produced by heat, fracture, contortion, upheaval, and denudation. The Student's Elements of Geology But a moment's consideration shows that there is an element of uncertainty about this, due to the steady denudation that all land surfaces undergo. A History of Science — Volume 3 In volcanic regions of deep denudation volcanic necks rise solitary and abrupt from the surrounding country as dome-shaped hills. The Elements of Geology The next interesting question is, How recently has denudation occurred? A journey in other worlds A romance of the future The transport by denudation of detrital and dissolved matter from the land to the ocean has had a most important influence on the events of geological history. The Birth-Time of the World and Other Scientific Essays These beds appear to be of littoral origin, and imply the previous emergence of the chalk, and its waste by denudation. The Student's Elements of Geology Hence, under ordinary circumstances, I conclude that for a cliff 500 feet in height, a denudation of one inch per century for the whole length would be an ample allowance. On the Origin of Species By Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life Under long denudation mountains are subdued to the forms characteristic of old age. The Elements of Geology Solvent denudation, as observed above, takes place mainly in the soils and in this way over the more level continental areas. The Birth-Time of the World and Other Scientific Essays The influence at once of climate and of elevation of the land may be appraised at their true value by the ascertained facts of solvent denudation, as the following table shows. The Birth-Time of the World and Other Scientific Essays This phosphatic bed in the suburbs of Cambridge must have been formed partly by the denudation of pre-existing rocks, mostly of Cretaceous age. The Student's Elements of Geology On the vast lapse of time, as inferred from the rate of deposition and of denudation. On the Origin of Species By Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life All this vast denudation may easily have been accomplished while their slow upheaval was going on; in several mountain ranges we have evidence that elevation has not yet ceased. The Elements of Geology The courses of stone in the building may be compared to successive strata, the quarry to a ravine or valley which has suffered denudation. The Student's Elements of Geology They arise under conditions where large stones or boulders are scattered in a deep deposit of clay, and where much of the denudation is due to water scour. The Birth-Time of the World and Other Scientific Essays Mr. Pengelly has confirmed Sir H. De la Beche's opinion that much of the upper portion of this old lacustrine formation has been removed by denudation. The Student's Elements of Geology Were it otherwise the subaerial denudation would be continually lessened by the diminution of the height and dimensions of the land exposed to waste. The Student's Elements of Geology It is not an uncommon error to imagine that the waste of sea-cliffs affords the measure of the amount of marine denudation of which it probably constitutes an insignificant portion. The Student's Elements of Geology Unlike those of the Vivarais, last mentioned, the basalt of this country was evidently submarine, and the present valleys have since been hollowed out by denudation. The Student's Elements of Geology They are but a fraction, as we have seen, of the total results of solvent denudation and represent the integration of the minute traces contributed by the river water. The Birth-Time of the World and Other Scientific Essays The above theory is by no means inconsistent with the opinion that the limits of the outcrop of the chalk and greensand which the escarpments now follow, were originally determined by marine denudation. The Student's Elements of Geology |
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