One nest had been made on an old packing-case left by the expedition which wintered there in 1894, and several nested among the weathering bones of the seals that had died on the beach.
The same weathering processes described above for igneous rocks cause considerable changes of economic significance in deposits formed as igneous after-effects.
The development of soils by weathering should not be regarded as a special process of rock alteration, unrelated to processes producing other mineral products.
These deposits have been enriched by weathering in the same manner as indicated above for the porphyry coppers, but to highly varying degrees.
The weatheringof a basic igneous rock, as in Cuba, may produce important residual iron ore deposits, which are also used as soils.
The zones formed by weathering and secondary enrichment are extremely irregular, both in distribution and depth, in any one deposit, and they overlap and grade into one another in a very complex fashion.
Weathering has concentrated the more resistant nickel at the expense of the more soluble minerals, and has produced extensive blanket deposits of clay, which in their lower portions contain nickel in profitable amounts.
Under weathering conditions, the silver sulphide minerals in general are oxidized to form native silver and cerargyrite, which are relatively insoluble and remain for the most part in the oxide zone.
In other cases they may be injurious, in that they limit the size of the blocks which can be extracted and afford channels for weathering agents.
Clay originates from the weathering of common rocks containing silicates, by pretty well understood weathering processes (see Chapter II).
Many mineral deposits owe their origin or enrichment to weathering and other related processes which are preliminary to erosion.
This would cause deep weathering of the surrounding slopes.
The Angelo Member consists of white to blue-white weathering limestone, marlstone, and mudstone.
Rock fragments which are the result ofweathering of a larger rock mass.
Only five days was, I compelled to "hole up" in my stateroom, hibernating, weathering the final rude shock of the Atlantic.
The queens were evidently weathering the first frosts and storms here, and waiting for the Indian summer to go forth and seek a permanent winter abode.
And so it is with this canyon; the weathering or the caving-in of these walls goes ever on.
After long exposure and great weathering it sank back, remained submerged for ages, and thousands of feet of strata were deposited upon it.
The weathering of the high grounds of the ancient crust by air and water furnished the material which formed the sandstones and mudstones and other sedimentary rocks, which are said to amount to a thickness of over fifty miles in all.
In the same part is a quantity of blackish material, weathering red and splitting on exposure like quicklime, and on all sides are heaps and scattered masses of dark heavy slag No.
The gravel beds result from weatheringof lower Coal Measure conglomerates.
Owing to the rough weathering of the stones accurate tracings were not possible, but the illustrations give a fairly correct idea of the inscriptions as they originally appeared.
Having completed our arrangements in regard to the security of the canoe, we now set sail to the south-southeast for the present, with the view of weathering the most southerly of the group in sight.
This morning we reached the western extremity of the field which had impeded us, and, weathering it, came to an open sea, without a particle of ice.
The geologist looks upon the land forms of the earth's surface as monuments which record the slow action of weathering and other agents during the ages of the past.
In much the same way weathering at last reduces to rounded hills the earth blocks cut by streams or formed in any other way.
Differential Weathering on a Monument, Colorado] =Bowlders of weathering.
Rock Sculpture By Weathering We are now to consider a few of the forms into which rock masses are carved by the weather.
In a broad way the changes which rocks undergo in weathering are an adaptation to the environment in which they find themselves at the earth's surface,--an environment different from that in which they were formed under sea or under ground.
We have seen how large is the part that water plays at and near the surface of the land in the processes of weathering and in the slow movement of waste down all slopes to the stream ways.
As the land surface is gradually lowered by weathering and the work of rain and streams, rocks which have lain deep within the zone of cementation are brought within the zone of solution.
We have seen that weathering reduces the angular block quarried by the frost to a rounded bowlder by chipping off its corners and smoothing away its edges.
As the surface of the land is slowly lowered by weatheringand running water, the zone of solution is lowered at an equal rate and encroaches constantly on the zone of cementation.
Running water has gulched the walls and weathering has everywhere attacked and driven them back.
As the waste mantle thins, weathering attacks the rocks of the region more energetically until an equilibrium is reached again; the rocks waste rapidly and their waste is as rapidly removed.
Pothole in Bed of Stream, Ireland] =Weathering of river beds.
Experience, and the weathering conditions, will suggest the amount of Relief to be given.
It is a good weathering stone, and has never been known to deteriorate.
In one of these nuclei by my side it is apparent that during the extension of the weathering process the phenocrysts of glassy plagioclase become opaque long before the groundmass is affected.
In the places where the surface deposits have been stripped off, these rocks are generally exposed as decomposing boulders, the spheroidal structure being well developed in the weathering process.
The rounded blocks that commonly occur on the surface may be regarded in each instance as the nucleus of a weathering spheroidal mass.
These caves have been produced by the more rapid weathering of the underlying clays and sandstones.
In places, where these rocks have been subjected to much hydration in the weathering process, they become red in colour, as is found on the flanks of Mount Mariko.
They are in the lower regions often decomposed to a considerable depth, the spheroidal structure being well displayed during the weathering process.
Originally grey in colour, they have been largely affected by the hydration accompanying the weathering process.
Like most of the caves all over the island they occur at the junction of the agglomerates and tuffs, and are to be attributed to the more rapid weathering of the underlying tuffs.
The basaltic andesites of the peninsula are often extensively decomposed through the weathering process, a spheroidal structure being then displayed.
Indeed, there is good reason to believe that the changes to be now described may be observed under the ordinary influences of weathering in a wet region.
On its west slopes are exposed yellowish-white tuff-like rocks, evidently the prevailing basic clay-tuffs which have become bleached through the hydration accompanying the weathering process.
On account of the more rapid weathering of the tuffs in the lower part of the cliffs, there is a rude shelter afforded by the overhanging portion which is the main feature of interest that the cliffs present from a native’s point of view.
It is to the spheroidal weathering that we must look for an explanation of the rounded boulders so frequent in these districts.
He then pointed out the succession of volcanic outbursts and the changes the rocks had undergone throughweathering and erosion.
The weathering was excessive and peculiar in contrast with that observed on fresh exposures near the Hut and at other localities near sea-level.
Within a few days of the taking of this picture the hut became so buried in packed snow that ever afterwards little beyond the roof was to be seen Weddell seals asleep on pancake ice Adelie penguin after weathering a severe blizzard.
Wadsworth says, "and ending against the fractured portion opposite," while the subsequent weathering and brushing might account for the slight difference in level of the lines on either side of the break.
Illustration: (Courtesy New Jersey Department of Conservation and Development) Soil is created from rock by nature's weathering processes and by plant growth.
If the buildings have been standing for a number of years, full allowance must be made for depreciation and repairs incident to weathering and long usage.
Jack waited for some time to see if it reappeared, but the shore remaining in perfect blackness he saw no good in delaying further, and weathering the Point, with its spine of jagged rocks running out to sea, ran straight for Wynport.
Some of these surfaces readily absorb agents, soweathering following decontamination is advisable.
The remaining agent can only be removed by weathering which can be accelerated through the use of heat and sweeping the surface with air.
Experiments to show loss in calorific heat values due to weathering indicate that such loss may be as high as 10 per cent when the coal is stored in the air, and 8.
The organisms are numerous; and, when we dig into the bank beyond the reach of the weathering influences, we find them delicately preserved, though after a fashion that renders difficult their safe removal.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "weathering" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: ablation; erosion; use; wear
