The denuding actions of air and water have, from the beginning, been modifying every exposed surface; everywhere causing many different changes.
Do we know any of these earliest aqueous beds, or are they all hidden from view beneath newer deposits, or have they been themselves worn away and destroyed by denuding agencies?
Such are volcanoes in the day of their perfection, before the denuding forces have made inroads on the symmetry of their form.
May not their denuding power have been far greater in old times than now?
So that when the ground being bare was most liable to be denuded, the water was least able to do it; and as the denuding power of the water increased, the land, being covered with vegetation, became more and more able to resist it.
The denuding and accumulating effects of ice thus give a contour to mountain valleys, and sculpture their flanks and floors far more rapidly than sea action, or the elements.
The denuding actions of air and water, joined with those of changing temperature, have, from the beginning, been modifying every exposed surface.
In this way volcanic tablelands have been formed which, attacked by the denuding forces, are gradually trenched by valleys and ravines, until the original level surface of the lava-field may be almost or wholly lost.
The forms of valleys have been governed partly by the structure and composition of the rocks, and partly by the relative potency of the different denuding agents.
Nevertheless we are by no means entitled to infer, that thedenuding force of the great ocean is a geological cause of small efficacy, or inferior to that of rivers.
This denuding process has been the work of ages when the sea was admitted into an original crater, and has taken place during the gradual emergence of the island from the sea, or during various oscillations in its level.
But we ought not to exclude entirely from our speculations another possible agency, by which the great cavity may in part at least have been excavated, namely, the denuding action of the sea.
He refers the numerous breaches, some of them very wide in the external ramparts of those islands, to the denuding action of the sea.
In these cases there are decisive proofs that neither the sea, nor any denuding wave or extraordinary body of water, has passed over the spot since the melted lava was consolidated.
In operating upon such cases the chief difficulty will be found in denuding the surfaces necessary for the introduction of the sutures, owing to the density of the cicatricial tissues, which are always present.
Nearly all are arranged in regular strata, and are composed of pulverized materials--materials ground down from pre-existing rocks by somedenuding and grinding action.
The waves are a great planing machine attacking the land, and the tides raise and lower this planing machine, so that its denuding tooth is applied, now twenty feet vertically above mean level, now twenty feet below.
These high tides of enormously distant past ages constitute the denuding agent which the geologist required.
Of all denuding agents, there can be no doubt that, to the land exposed to them, the waves of the sea are by far the most powerful.
It goes on steadily, but so slowly that it is estimated to take 6000 years to wear away one foot of the American continent by all the denuding causes combined.
They cooled in the crust of the earth amongst the strata between which they were intruded, and have only been exposed to view by the action of the denuding forces which have worn away the sedimentary beds by which they were formerly covered.
Not only have the upper portions of these volcanoes been swept away, but their lower portions, likewise, have been deeply incised, and thousands of feet of solid rock have been carried off by the denuding forces.
Another long period now ensued, during which the inland sea disappeared, and its dried-up bed was subjected to the denuding action of the sub-aerial forces.
Many of the more ancient mountain-chains and ranges, however, have been exposed so long to the abrading action of the denuding agents that all trace of their original contour has vanished.
Take another example of what denuding agents have done within a recent geological period.
An anticlinal arrangement of strata is a weak structure--it readily succumbs to the attacks of the denuding agents; a synclinal arrangement on the contrary, is a strong structure, which is much less readily broken up.
It is true that now and again streams are found flowing in the direction of a fault, but that is simply because the dislocation is a line of weakness, along which it is easier for the denuding forces to act.
They have been carried away grain by grain by the denuding forces--by weathering, rain, frost, and fluviatile and marine action.
Tidal and other currents may also have some denuding effect upon the sea-bottom, but this can only be in comparatively shallow water.
It may be concluded that the present physiography of the land is proximately due solely to the action of the denuding agents--rain, frost, rivers, and the sea.
Cornwall, are not affected by any of the dislocations, a powerful denuding force having clearly been exerted subsequently to all the faults.
It is clear that such rocks, formed of mud and sand, now for the most part consolidated, are the monuments of denuding operations, which took place on a grand scale at a very remote period in the earth's history.
There is a red sandstone which seems to underlie the limestone, and wherever that rock outcrops, the soil is excessively thin and poor, and the denuding power of the rains is very marked.
From that time onward, the Archean range must have dwindled away, what with the encroachment of the Atlantic on its eastern shore and the general action of denuding forces on its surface.
The difference between constructional forms and those forms that are due to the action of denuding forces is in a general way so easily recognized, that immaturity and maturity of a drainage area can be readily discriminated.
No doubt at one time it was largely covered with basic tuffs and agglomerates, but these deposits have been almost completely stripped off by the denuding agencies, and were only noticed in one place on the western flank.
Marine and sub-aerial denuding agencies have shaped and re-shaped the surface to such a degree that it is now impossible to restore it in imagination.
They seem generally to have been stripped off by the denuding agencies; and only at times, as around the slopes of Ndrandramea and Thokasinga, are to be found the remains of agglomerates of the same formation.
Their scarcity at the sea-border is to be attributed to the denuding agencies.
Both, however, belong probably to the same vent of which now the exact situation would not be easy to discover, on account of the re-shaping of the surface through the denuding agencies.
After the emergence the subaerial denuding agencies reshaped the surface, and as a result of the less yielding character of the materials filling the fissure, they protrude as a dyke-like mass from the crest.
This is in favour not only of the sufficiency of time, but also of the ability of the denuding agencies to strip off the surface-deposits.
Since that period, the configuration of the crater-basin has been greatly modified through the denuding agencies.
In the course of ages the original configuration of this great hollow has doubtless been extensively modified by the denuding agencies.
But this amount, great as it is, is undoubtedly below the original maximum, as the uppermost sheets have been removed by denuding agencies, we know not to what extent.
As Scotland is a mountain region of rather abundant rainfall, the denuding power of its rains and rivers is probably rather above than under the average, but to avoid any possible exaggeration we will take it at a foot in 4,000 years.
The Po, on the other hand, is wholly in a district of abundant rainfall, while its sources are spread over a great amphitheatre of snowy Alps nearly 400 miles in extent, where the denuding forces are at a maximum.
Yet again, the earth's rotation was certainly more rapid in very remote times, and this would cause more impetuous tides and still further add to the denuding power of the ocean.
The Dutch Protestants, as I remarked at Utrecht, have shown singular efficiency in denuding religion of its external graces and charm.
There a still finer conglomerate is seen, in a thin hard layer, sticking to the surface of the gneiss, evidently the tenacious remnants of a thick bed that has been scraped off by the powerful denuding forces once so active in this region.
The same denuding processes have been at work, as already remarked, on the Torridon peaks round Loch Torridon and Loch Inver.
But Scotland has been subjected to extraordinary denuding forces all over its surface, from John o' Groats to Galloway; such peaks remaining as wonderful monuments both of what once existed and of what has been swept away.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "denuding" in a variety of sentences. We hope that you will now be able to make sentences using this word.
