Congrès géologique international

“ The road descends rapidly in geological horizon, as well as topographically, and in a few miles enters the massive gray sandstones of the Laramie Cretaceous, in which Price river has cut a narrow, winding, and ever-deepening gorge, whose walls show a great variety of castellated forms due to erosion. The finest of these is just above Castlegate, where a narrow column of sandstone, over 500 feet (152 m.) high, stands at the end of a sharp, narrow ridge like the watch-tower of a castle. ”

“ From the Falls to Fort Snelling the rock on the sides of the gorges has a freshly broken appearance, the large fragments thrown down by the action of the water on the easily crumbled sandrock, as the till's receded, still existing in the talus below the bluffs. Throughout this extent the strata are horizontal, the thickness of the drift sheet overlying them nearly uniform, and all other conditions, so far as they can he seen, that would affect the rate of recession, seem to have exerted an unvarying influence. ”

“ Il n'y a aucun pays où vous ne soyez reçus avec empressement, de même qu'il n'y a pas de peuple qui ne bénisse vos travaux et vos découvertes. Mais plus encore êtes-vous les bienvenus dans cette grande République où nos institutions, nos progrès et nos espérances sont fondées sur la diffusion des connaissances utiles. Votre science, bien que la plus jeune, occupe déjà un des premiers range parmi ses aînées par l'exercice de la pensée librement exprimée et par ses nobles aspirations. ”

“ Si la forme, quelle que soit sa vraie nature, a quelque chose de défini et de distinct, quelque chose qu'on puisse reconnaître partout et n'importe où, et si elle est caractéristique d'un certain horizon ou d'une certaine localité elle devient proportionnellement utile pour fixer l'âge de quelque autre dépôt où elle se trouve. Si elle ne se trouve que dans deux localités ou à deux points à la surface de la terre, on en peut conclure légitimement, quoique pas d'une manière absolue, que les deux terrains sont d'un âge assez semblable, la preuve du contraire faisant défaut. ”

“ Ici, au Nouveau Monde, jeune dans sa civilisation mais vieux par sa formation géologique, il peut tracer, plus clairement et avec plus de certitude qu'ailleurs, la structure géologique de notre globe, ses longues périodes géologiques variées, et étudier plus soigneusement l'étendue, ainsi que les effets, de l'action glaciaire. ”

“ Mais quel est le pays qui seul peut prétendre au droit d'être la patrie de la science ou de ceux qui s'y sont dévoués? Il suffit de contempler cette vaste assemblée, composée de membres distingués et illustres du Vieux et du Nouveau Monde, pour voir que vous ne pouvez être considerés comme des étrangers en aucun lieu où les connaissances utiles sont désirées et où l'humanité se développe. Dans le domaine de
la pensée les frontières des nations cessent d'exister, et même l'amour de la patrie se transforme et s'élève jusqu'à l'amour du prochain. ”

“ The main mass of Green mountain is made up of Denver beds. Contact with the Arapahoe beds is most clearly indicated in the ravine first mentioned and in others on the western slope of the mountain; the lower 200 or 300 feet of the formation are, however, not very continuously exposed in any section. But a characteristic conglomerate composed of dark andesitic pebbles is clearly shown at the western base of the more abrupt slopes of the mountain, and from this horizon to the summit there is an almost continuous section illustrating very clearly the characteristics of the formation. ”

“ But going westward from the Archean belt the unaltered rocks are not found in the same order. The tough Carboniferous limestone that holds its own so valiantly on the summit does not appear at the west, as it should if the structure of the mountain were anticlinal; but the first strata seen, after passing the valley gravels, which bury the base of the Archean wall, are of Cretaceous age, and they dip toward, rather than from, the ridge. The mountain is a great but simple monoclinal mass, bounded on the west by a profound fault, along the line of which is the river valley. ”

“ One of the fault-caused terraces of the northern flood plain has been utilized in the construction of an ore-smelting establishment. It is an impressive fact that the stream, a roaring torrent every spring, has not yet been able to reconstruct its dislocated flood plain.
We are here brought face to face with a process of mountain-making in actual progress. The Wasatch has grown perceptibly within a few years, and the gathering orogenic strains may culminate any day in another convulsive leap. It is a dictum of dynamic geology that great mountains are young mountains ”

“ The structure of individual districts and regions could be worked out and the formations correlated, but the attempt to equate the Cambrian, Silurian, Devonian, or Carboniferous of one region with rocks of the same age in a far distant one would be an almost hopeless undertaking. In the Carboniferous the beds of coal would serve as an important guide, but, if implicitly followed and no fossils were available, the Triassic of Virginia, the Carboniferous of the central United States, and the Cretaceous of the west would be placed together. ”

“ The height of the Falls is about 160 feet (48 m.) ; the pool below the cataract has a depth, at the nearest point where sounding has been successful, of 185 feet (56 m.) . This great depth of pool appears to be essential to rapidity of recession, for under the American fall there is no pool and there the recession is slow. But the river has a depth comparable with that of the pool for only a mile or two below the cataract, and at most other points the Present cross section renders it improbable that a deep pool was ever formed. ”

“ The road now descends the valley of Price river nearly to the Colorado river, through a region of almost horizontal Mesozoic and Tertiary beds which are uninfluenced by the Wasatch upheaval. This region is not only of modern geological formation, in that it is traversed by no known lines of long continued dynamic movement, and hence owes its topographical form entirely to erosion, but its erosion is of the type peculiar to an arid or practically rainless region whose streams are fed only by the precipitation on high areas outside of the region. ”

“ In the Salt Lake basin there is no historical record of their formation, but many of them intersect the beaches and deltas of the Bonneville shores, and some are so fresh that vegetation does not yet clothe them, and it is bard to believe their antiquity is measured by centuries rather than decades. They have been found along the bases of a dozen ranges of the Salt Lake basin, but they are most persistent and have greatest magnitude at the western base of the main ridge of the Wasatch chain, where they have been traced almost continuously for a hundred miles. ”

“ If it is premised that all clastic and fossiliferous rocks more ancient than the Olenellus horizon are Cambrian, it is useless to try to prove that there are pre-Cambrian clastic rocks which bear life. It is, however, necessary to recognize that the carrying downward of the term Cambrian to cover not only the great thicknesses of rocks which are now included but all pre-Olenellus clastics, will probably make the Cambrian as great as, or greater than, all the subsequent periods put together. ”

“ Puisse-t-elle, Messieurs, grandir avec nous et augmenter ses forces en même temps que les nôtres, jusqu'à ce que, comme les couches diverses des différentes régions du globe produisent les sols essentiels à l'existence humaine en chacune d'elles et contribuent au
bien-être et au progrès de tous, dans l'avenir, tous les peuples de la terre ne forment qu'une seule famille et que la fraternité et l'intelligence, non la force ni l'inimitié, soient les sources de notre prospérité Puisse votre séjour au milieu de nous vous être agréable ”

“ The bathing establishment is on an island in the river opposite the town, and consists of handsomely appointed bath buildings, back of which is an open-air bathing pool of masonry, nearly 700 feet (213 m.) long, at one end of which a stream of hot water from the springs* is constantly pouring in, while at the other is a fountain of cold mountain water, so that the bather can find any desired temperature. There is also a natural steam bath, arranged in a cave in the limestone on the south bank of the river just above the town. ”

“ A hundred miles or more further down the stream the basalts have been observed to rest directly on sedimentary beds of recent age, probably deposited in some inclosed fresh-water lake. Other cascades and falls are known to exist along the course of the Snake River, but its canyon has never, so far as known, been followed continuously, and their number and its extent is unknown. The stream is unusually rapid for its size, in spite of these many leaps in its course, and is cutting down its bed very fast, though yet far from reaching a baselevel of erosion. ”

“ Through an immense area, comprising the half of Colorado and Utah and the greater part of Arizona and New Mexico, there is scarcely an acre on which shards of Pueblo pottery may not be found. Though the houses are of stone, the mortar employed has no lithifying principle and yields to the storms, so that the walls of abandoned houses are apt to fall, but a multitude of structures built in shallow caves on the faces of cliffs have been preserved, enabling the student to assure himself of the identity of the culture represented by the ruins with that of the modern villages. ”

“ The representatives of the period may be shore deposits in one place, those of off-shore in another. Again, as a rule, outside of Lake Superior the exposures of pre-Cambrian rocks occur in regions of great folding. And here, through dynamic action and the metamorphosing processes that accompany it, the rock has not only often wholly lost its original character, but the same formation varies in the most protean manner with the varying conditions of metamorphism to which it was subjected. An excellent illustration of this is the Lower Cambrian quartzite of the Green Mountains. ”

“ Or, par la force des choses, chacun de nous est entraîné à étudier des points spéciaux ; pour faire des œuvres originales, on doit concentrer ses forces sur une partie seulement de la science. Quelques-uns parmi nous se plaisent dans la recherche des vertébrés, parfois étranges ou gigantesques, qui peuplèrent nos continents dans les temps passés; d'autres s'attachent aux invertébrés, créatures plus humbles, mais qui rendent de plus grands services aux géologues pour la détermination des âges de la terre. D'autres encore considèrent les développements successifs des flores. ”

“ The substructure of the Plains in this latitude is formed by strata of Paleozoic, Mesozoic, and Tertiary ages, which lie nearly in position of original deposition, and show no preceptible discordance of stratification between the beds of successive series. The surface is masked to some extent, especially along the more important valleys, by a loess-like deposit which gives great fertility when rainfall is sufficient for cultivation, or when, as near the mountains, a sufficient supply of water may be obtained for irrigation. ”

“ Lying upon the surface of this travertine on the top of the mountain are found glacial boulders brought from the summit of the Gallatin range, 15 miles away, which have been transported on the ice sheet across Swan valley and deposited on the top of the mountain, 700 feet above the intervening valley. They offer the strongest possible evidence that the travertine is older than the glacier which has strewn the county with transported material. How much travertine was eroded by ice it is, of course, impossible to say, but so friable a material would yield readily to glacial movement. ”

“ It is a grand exposure of rhyolite walls, exhibiting remarkable forms of rock erosion. The river makes a rapid descent, and at Gibbon falls, 80 feet high, flows over a fine example of obsidian worn smooth by the rushing waters. Along the base of the canyon walls, in close proximity to the river, steam vents and hot springs mark the course of thermal action. Beryl spring, on the west bank near the northern end of the canyon, is worthy of attention from the exquisite coloring of the constantly agitated water which has built up a delicate rim of sinter encircling the pool. ”

“ Again, quartzites from the Appalachians to the Black Hills have been correlated on no other ground than lithological likeness, as though thick sandstone formations, which subsequently have been cemented to quartzites; have been produced but once in the history of the world. To some geologists the degree of crystallization has been the controlling fact. In other cases the occurrence of some mineral or association of minerals has been the ground upon which the reference of the containing formation is made to some specific period. ”

“ The mountain from which the name Catskill (Kaaterskill) is derived is a conspicuous feature at the right (west) . At Newburg the Trenton limestone occurs with but little alteration, and just beyond it the train enters the area of crystalline schists, to which the mountain range known as the Highlands belongs.
The train then passes through the gorge of the Highlands, keeping close to the water's edge. Above it the old base level plain holds place as a terrace within the gorge. ”

“ There are no streams, and springs are rare. Hull spring, the first one seen by the party, is a day's journey from Flagstaff and determines a point of encampment. The degradation of the country has here progressed several hundred feet since the spreading of a great field of basaltic lava, and the beds of resistant basalt cap a mesa facing toward the north. Beneath are soft shales of Permian age, and the water stored in the crevices of the basalt escapes slowly at the plane of contact. ”

“ It is plain from the great diversity of opinion as to the origin of the Archean rocks, and from the fact that many of the opinions are beliefs rather than verified conclusions, that we have no definite knowledge upon parts of the subject. That there are comparatively few or no wholly massive rocks in this complex is precisely what would be expected under any theory. ”

“ For several geologic periods the Appalachian region has stood at so low a level that its streams have had small declivity, and mechanical erosion has been slow. The chemical factor in erosion has thus acquired relative prominence, and the broad outcrop of lower Paleozoic limestone which occupies the valley area has been degraded by solution until its surface is far below the contiguous outcrops of sandstone and shale. It is an undulating plain, sharply incised along principal lines of drainage and otherwise characterized by "swallow holes" or "limestone sinks, and by caves. ”