Various

“ The narrow passage of the Quinnipiac through a sandstone ridge southwest of Meriden cannot belong to the same cycle of erosion as the broad sandstone lowland on either side of it, but manifestly must be much younger. So, also, the narrow passage of the Farmington at Tariffville, where it crosses the trap ridge through a gorge free from drift, is of much later date than the broader valley more or less encumbered with drift which the upper part of the same river has cut in the hard crystalline schists. ”

“ In the study here outlined the question whether the water bodies which formerly occupied the Laurentian basin were lakes or arms of the sea, should not be difficult of direct and positive determination. If fossils can be found within the basin, they might yield definite testimony, but even if they are absent or if their evidence is inconclusive, topography can be appealed to with the expectation of receiving a conclusive decision. ”

“ The reduction in cost of production has been entirely brought about by improvements in mining machinery, by a more thorough understanding of the nature of the deposits to be worked, and by more intelligent management and labor. The reduction in cost of production is nowhere better seen than in the materials most necessary to our welfare. ”

“ The mining products of the United States are far more important in their aggregate value than those of any other country in the world, though, in many individual products, other countries supply more than the United States. This country is first, however, in the production of pig iron and steel. It is also first in the production of copper, gold, silver, petroleum, and a number of other products. ”

“ It would seem that if the earth originally had a crust on which the first sediments were deposited when the temperature became sufficiently low to permit water to condense, that the said water, at a very high temperature and under what are to us now inconceivable conditions but little removed from fusion, might give rise to sediments not altogether similar to those formed by the ordinary processes of erosion at the present time. ”

“ It seems probable, therefore, that from a solution of iron and manganese in surface waters the iron might, where the conditions are favorable, be precipitated as sulphide (FeS2) and the manganese might be carried on in solution to be deposited somewhere else as oxide or carbonate. Subsequently the oxidation of the ores would give rise to oxide of iron from the sulphide and oxide of manganese from the carbonate; and the two ores, though occurring at the same horizon, would be separated by a greater or less distance. ”

“ There is naturally no room at or near the water level, even for the wagon road, place for which has been blasted near the top of the gorge. The profile of the gap shows a gentle ascent from the top of the gorge, up to the nearly level crest line of the ridge. That is to say, the recent gorge has been cut in the bottom of a sag in the ridge. We have already given our reasons for believing that the gorge here is much younger than the Westfield river gap; that it is a part of the work of the next cycle; that it is post-Tertiary. ”

“ Frequently the iron and manganese which were originally finely disseminated through shale, sandstone, etc., are subsequently concentrated into bodies of comparatively pure ore, and very commonly this concentration takes place by a process of re-solution of the iron and manganese and re-deposition by replacement with limestone, or, more rarely, with some other material. ”

“ Moreover, deposits sometimes occur which are composed largely of manganese ore, with little or almost no iron, and when the source of the manganese is looked for, we often find that the rocks which probably supplied it contained both manganese and iron, and that the iron was present in a much larger proportion as regards the manganese than in the new deposit. ”

“ However, as described by Irving, between the heavy beds of quartzites are often layers, cut by a diagonal cleavage which dies out in passing into the thick beds. The layers showing cleavage sometimes pass into those showing the beginning of foliation, the rock then nearing a schist. In the centers of the schist zones, the schistosity approaches parallelism with the bedding, and in passing outward curves from this direction until it crosses the bedding at an angle, at the same time becoming less marked and grading into ordinary cleavage, which dies out in the quartzite. ”

“ In popular parlance the country is “hilly.” It is uneven, not because there are high hills, but rather because there are deep valleys. If in imagination we fill up these valleys and the wide Triassic lowland to the general level of the broad inter-stream surfaces, we shall have constructed a gently undulating plateau, dipping to the south and east—a peneplain.36
Origin of the peneplain. This is not a constructional surface, for the rocks are greatly tilted, folded and faulted, so that the surface consequent upon such disturbance must have been complex and mountainous. ”

“ If the supply of metalliferous solutions were not continuous, but were intermittent, as is sometimes the case in local basins, such as coastal lagoons, which are often dependent for their supply of water on the changes of season and the sudden fluctuations of weather, then interstratified layers of iron and manganese ore might be produced. The iron, becoming oxidized on the surface, sinks to the bottom, possibly in some cases to be converted there to the simple carbonate by organic matter. Further oxidation precipitates hydrous oxide or carbonate of manganese on top of the iron. ”

“ Outliers of Cambro-Silurian age are also found at several points lying well within the margin of the Nucleus, as for instance in the Ottawa River about Pembroke at a distance of fifty miles, and at Lake St. John at the head of the Saguenay River at a distance of one hundred and thirty miles from its present limit. There is reason to believe that a similar outlier exists in the interior of the northern part of the Peninsula of Labrador, so that the Lower Paleozoic sea must also have covered considerable areas in the eastern half of the Protaxis, where now nothing but Laurentian is to be seen. ”

“ For instance, coal can in some cases be carried by rail for 400 miles and delivered on board vessels for from $2 to $2.25 per ton, and yet the mine owners and railroads make dividends; some of the manufacturing establishments in Western Pennsylvania obtain coal at from 60 to 75 cents per ton at their works; hard gold-bearing quartz can be crushed, washed and 95 per cent. of the gold saved on the plates for $1.25 per ton; high grade Bessemer iron ore can be mined, handled, shipped and delivered a thousand miles from the point of production for less than $4.00 per ton. ”

“ With the changes of the physical geography clearly in mind, the rivers of Connecticut may now be examined in respect to their conditions of origin, the number of cycles through which they have lived, and the approach they have made to mature old age. ”

“ In many cases certain horizons are characterized over large areas by iron alone, and but little manganese, as is well seen in the Clinton formation and in the Tertiary iron-ore horizons of Arkansas and Texas; while, on the other hand, some areas of certain horizons contain considerable quantities of manganese and very little iron, as is seen in parts of the Marine limestone in New Brunswick and Nova Scotia, and also in parts of the metamorphosed Cretaceous shales of California. ”

“ The consequences of this uplift are seen in the valleys, which are cut into the peneplain, and which have destroyed the level character of the country. In the hard crystalline rocks the valleys are generally narrow and deep, with bold slopes;39 where they are cut in the crystalline limestone, they are wider and more open. In marked contrast, however, is the lowland on the Triassic area in which only the trap ridges remain to tell of the former altitude of the general surface, and the immense amount of erosion which has taken place on the soft sandstones and shales. ”

“ When iron and manganese ores occur in more or less separate deposits, it becomes necessary to suppose the action of influences different from those which cause the deposition of both together, and such influences are to be found in the different modes of precipitation, under certain conditions, of the two metals. It has been shown by Fresenius28 that certain warm springs, on reaching the surface, first deposit hydrous sesquioxide of iron, and farther on carbonate of manganese. ”

“ No change will take place in the surface of the hydrosphere. If the surface of the 141,700,000 square miles of lithosphere were reduced to uniformity, the whole depressed area would lie .66 mile beneath mean sphere level, and the depth of the ocean becomes 2.36 miles. To raise the land to its actual mean level above the hydrosphere surface, a sufficient quantity of matter must be removed from the depressed area and placed on the elevated block. Let x = the thickness of the belt removed and y equal the thickness of the belt when placed on the elevated block. ”

“ Fresh sections, particularly of the stratified clays, are exposed from time to time by artificial excavations, in which much of their history may be learned. Not only should records be made of the facts noted at special excavations, but the extent and character of the stratified deposits in one area should be determined and compared with similar data obtained in other areas. For example: the clays covering large tracts on the west shore of Lake Michigan and on the southern and western border of Lake Superior are of a red color, while other areas bordering Lake Erie are covered with blue clay. ”

“ In some cases nearly every grain has thus grown, perfectly indurating the rock. But, also, nearly every grain of quartz has a wavy extinction, and many of them have been fractured, as mentioned of a few of the quartz grains of the quartzites of the south range. In one case the pressure has been so great as to produce rather numerous roughly parallel lines of fracture. It is thus seen that the dynamic effects are not confined to the schist zones, but are also prominent within the heavy beds of quartzite. ”

“ Bell states that some of the mountains on the Labrador coast now rise to a height of from 5,000 to 6,000 feet, while Lieber has estimated that on the coast of Northern Labrador they rise to a height of from 6,000 to 10,000 feet. Along the southern part of the Protaxis, where the country is much lower, notwithstanding the enormous subaerial denudation and glaciation which the area has repeatedly undergone, there are many points still rising from 2,500 to 3,500 feet above sea level, while Logan estimated that the average elevation is from 1,500 to 1,600 feet. ”

“ Lawrence and Champlain valleys, where clays containing marine fossils occur up to a certain horizon and record a Pleistocene invasion of these depressions by the sea. If the adjacent Ontario basin was occupied by the sea about the same time that the Champlain valley received its filling of clays containing marine fossils, there is every reason to believe that the deposits and their contained fossils in each basin would have been essentially the same. ”

“ Whatever was their origin there must have been abundant opportunities during the long erosion which resulted in the Cretaceous baselevel, and again in the period of revived and quickened degradation succeeding the post-Cretaceous uplift, for the streams to adjust themselves in a large degree to the geological structure. The contrast of hard and soft beds and the great elevation must have been potent factors in bringing to pass such a result. ”

“ In the schists of the shear zones, as at the south range, the thin sections show that the original quartz grains were small; interstitial material was present, and mica has developed more largely than in the quartzite. However, in the most crystalline phases, the fragmental cores of the quartz grains and their frequent enlargements are plainly seen. Thus the shearing has not been sufficient to produce a completely crystalline schist, although this would not be macroscopically discovered, unless it were suspected because the rock is not thinly foliated. ”

“ On the contrary, many of the mining industries where the greatest reduction in cost of production has been accomplished, are carried on with high priced labor; and in many other cases, where the wages are not high, the condition of the wage-earners has been greatly improved. ”

“ A fault zone of limited throw exists. All phases are exhibited, between a massive quartzite, showing macroscopically little evidence of interior movement through a rock exhibiting in turn fracture and cleavage, to a rock which macroscopically is apparently a crystalline schist. The foliation of the schists is parallel to the original stratification, being consequent upon the movements of the beds over one another, readjustments occurring mainly in the softer layers. ”

“ At the upper narrows of the Baraboo, near Ablemans, we are on the north leg of the anticline. The dip is throughout from seventy to ninety to the north, and in some places the layers are slightly overturned. The slipping along the bedding has here been much greater. While in this area there are heavy beds of quartzite which have not suffered great interior movement, other beds have been sheared throughout, being transformed macroscopically into a quartz-schist, but the foliation is strongly developed. ”

“ In conclusion, it may be said, that as a piece of statistical work, relating to an industry that is world-wide in its scope, combining accuracy with full detail and systematic arrangement, and issued so soon after the close of the time to which it relates, the Mineral Industry has never been equaled in this country or abroad. The former statistical numbers of the Engineering and Mining Journal, which referred mostly only to American mining, were considered remarkable pieces of statistical work, on account of the promptness of their publication ”

“ This development of the Laurentian is known as the Grenville Series, and has been considered by all observers to be above and to rest upon the Fundamental Gneiss. In it are found all the mineral deposits of economic value—apatite, iron ore, asbestos, etc., which occur in the Laurentian. The rocks of this series, though generally highly inclined, over some large areas lie nearly horizontal or are inclined at very low angles, but even in such cases they show evidence of having been subjected to great pressure, resulting in some cases in the horizontal disruption of certain of the beds. ”

“ Frequently a given geologic horizon is characterized by both iron and manganese, though in one case it may contain only iron, in another only manganese, and in still another iron and manganese mixed in various proportions. A remarkable case of this is seen in the iron and manganese horizons immediately above, or a short distance above, the Paleozoic quartzite, on the east side of the Appalachian Valley, especially in the Valley of Virginia.13 Here deposits of iron ore, of manganese ore, and of both ores mixed, are found at various points along the same geologic horizons. ”