Fall and rise of sudden. time of this disturbance of the strata, appears to have been very sudden. This is shown by a peculiarity in the contour of the dethe waters very posit, which is uniform in all the sand shores of this part of the coast. As you go out into the lake, the bottom gradually descends from the water-line to the depth of about five feet, when it rises again as you recede from the shore, and then descends toward deep water, forming a subaqueous ridge or "bar" parallel to the beach, and some ten or twenty rods from the shore. This is shown at the point marked B in the section, Fig. 4. The upper beach preserves its old bar perfectly (marked in the cut), as if the lake had left it but yesterday. The quickness of the change is obvious to any one accustomed to lake-shore action; for had the water occupied even two months in receding from the bar, the waves would have torn it in pieces and covered it with new sand, leaving nothing distinguishable of its form. Another proof of the suddenness of the retirement is, that there are no sand ridges between the upper and middle beaches. The ground is bare clay, just as the waters left it, and the valley between the two beaches, which is generally about two miles wide, is absolutely continuous for a hundred miles, surrounding the head of the lake. . . . The waves of Lake Michigan act upon their shores with tremendous force, and are always engaged in either piling up the sand or tearing down the clay. There is no possibility that they could effect a slow retreat down such a slope without leaving marks which no time could erase. We have on this shore examples both of slow and of rapid recession, and the comparison of the two establishes the above conclusions. Singularly enough, says Dr. Andrews, this subsidence was at first not to the middle beach, but to the lower one. . . . The waters fell from the upper beach to about the present level so suddenly that they not only left the subaqueous "bar" almost undisturbed, but they did not throw up a single intermediate beach-line, which, at the rate of sand deposit prevailing in this region, would have been visible if there had been a pause even of six months. The waters remained here long enough for a thin stratum of peat to form, and then rose again over the soilbed and deposited the middle beach upon it. . . . From the upper edge of the middle beach the water receded very slowly, occupying probably two thousand years or more in falling a few feet, and throwing up, where the sand-supply was most abundant, numerous parallel ridges. It then fell perhaps ten feet more, pretty rapidly, to the upper part of the present beach, leaving a continuous valley between the middle and the modern sands. This last recession, however, was not so sudden as that from the upper line, as shown by the fact that the subaqueous bar was demolished by the retiring wave action, and a considerable amount of sand was left between the middle and lower beaches. Identification of middle beach. the One of the most important results of this investigation is the probable identification of the high water of the middle beach with the more general submergence of the Loess. The Loess is the Loess with not a continuation of the Boulder Drift, as is often sup- period of posed (says Dr. Andrews); on the contrary, it is separated from the true Drift by a stratum of vegetable mould, marked with subaerial denudations, showing that a period of dry land and vegetation intervened between the close of the Drift and the submergence called the Loess. . . . The following sections will show the relations of the deposits on the lakes and on the Mississippi : SECTION OF THE MISSISSIPPI. Modern Soil. (Water at its lower level.) Loess. (General submergence near the rivers.) Ancient Soil. (Water at its lower level.) Boulder Drift. SECTION OF THE LAKE SHORES. Modern Soil. (Water at its lower level.) Ancient Soil. (Water first at upper and General results reached. It appears, therefore, that the general order of events on the lakes and on the Mississippi has been identical, and that the high water of the middle beach occupies exactly the same place in the series as the high water of the Loess near the Mississippi. There can hardly be a doubt, therefore, that the two were cotemporaneous. Dr. Andrews sums up the history and chronology of the lakes as follows: 1. The upper beach began to form immediately after the Boulder Drift period, and continued to accrete for about nine hundred years. No animal fossils have yet been found in it. 2. The waters then fell suddenly to about their present level, where they remained till a thin bed of peat accreted on the marshy slope 506 He has not been able to collect data for a calvacated by the waves. culation of this first low-water period, but, from the position of the soilbed in the eastern dunes, inclines to think it lasted five hundred or one thousand years. 3. The water rose again, submerging for a short time the upper beach, but soon fell to the line of the middle one, where it remained about one This period appears to thousand six hundred or two thousand years. be cotemporary with the Loess. 4. The water, which had already slowly fallen some feet, now retired more rapidly to near its present level, which it has maintained with only moderate fluctuations ever since. these deposits appears to be somewhere 5. The total time of all between five thousand three hundred and seven thousand five hundred years. This result is, of course, entirely at variance with the enormous figures demanded by Sir Charles Lyell and the deriders of "the current cosmogony;" but it corresponds with the conclusions we have reached on other and independent evidence; and it is for an intelligent public to decide who is right. NOTE. We learn from Dr. Andrews that Dr. Lapham, of Milwaukee, suggests that the lakes may have stood for long periods at lower levels than the present one, and that he (Dr. Andrews) has not allowed anything for such lower-level periods. In support of this, Dr. Lapham calls attention to the fact that the channels of the rivers running into the lake are often much deeper than the adjacent bottom of the lake itself, indicating ancient lower channels. To this Dr. Andrews replies, that rivers, like brooks, cut deepest where the current is swiftest, and that the ancient greater size of the streams, as well as the modern spring floods, would cut out these deeper places, while at the point of entrance into the lake the motion is checked, and the channel is either cut less deeply, or, if cut, is filled There is a narrow, swift place in Wisconsin River which is one hunagain by the waves. dred feet deep, yet two miles lower down the stream the rock bottom rises nearly to the surface, though the descent of the surface itself is very slight. Furthermore, numerous borings and deep-water dredgings, as well as a regular shaft sunk in the bottom of the lake two miles from shore, and a tunnel dug from the shore to the shaft, fail to find any traces of the submerged beaches which ought to exist under the lake if it ever had a much lower level than the present. Dr. Andrews also writes us that since he wrote his article on the lake beaches he has discovered that the deluge of the middle beach went temporarily much higher, and even laid a stratum of muddy gravel over the black soil which had accumulated on the upper beach. This higher part of the inundation is probably, he remarks, the true analogue of the Loess deluge. The water remained at this upper limit for a very brief period-not long enough to lay down a definite shore-line. On page 501 we state that "the body of water along the shores of Lake Michigan is in This is spoken of the currents which affect the sand beaches of motion southward," etc. the calculation there made. The well-known northward current on the northern portion of the east shore is too far away to influence this region. CHAPTER XXXIV. SIBERIA. Preservation of the Mammoth.-The Bones found as far South as Lat. 56°.-Mr. Howorth on the Extinction of the Mammoth.-Great Changes in the Climate and Physical Geography of Siberia.-The Former Existence of a Great Asiatic Mediterranean.-The Sudden Draining of this Sea, by which the Mammoth was destroyed.-Sudden Change in the Siberian Climate.-The Tundras of Siberia.-The Ancient Hyrcanian Ocean.— Evidences that the Caspian formerly covered a much greater Area.-No Glacial Age in Siberia.-The Destruction of the Mammoth and the Preservation of his Remains in the Ice subsequent to the Date of the Glacial Age in Europe.-Tartar Traditions of the Mammoth.-M. Dupont on the Climate of the Quaternary Period.-A Pre-historic "Find" in Siberia.-Bronze Relics.-Representation possibly of the Mammoth.—Observations of M. Desor.-The Bronze-Workers of Siberia cotemporary with the Mammoth. -Are these Bronzes Etruscan ?-The "Tomb-Building" Races.-Connection between the Etruscans and the Altaic Tribes.-Mr. Taylor's "Etruscan Researches." THE preservation of the carcasses of the mammoth in Siberia is referred to the fact of their being imbedded in the ice or in the frozen soil. The bones of the mammoth, as we have stated, are found, however, in all the lowland of Siberia,—in the west as well as in the east, and between lat. 60° and the Arctic Ocean. Lyell mentions that Pallas observed them as far south as lat. 56°, below the city of Krasnojarsk, on the Yenisei, in strata of yellow and red loam, alternating with sand and gravel.* The ground has hardly remained permanently frozen in this region, as the climate of Siberia is much milder in the west than in the east, and as the summers at Krasnojarsk, though short, are very hot. The well-preserved carcasses of the mammoth are found ordinarily beyond the Arctic Circle, and in the east.† The fresh state of these bones, or of the ivory associated with them, precludes, therefore, it appears to us, the idea that they can have any such antiquity as several hundred thousand years, even if we could be * Erman mentions that many well-preserved mammoths' skulls were seen by him at Malmish, which had been dug up from the alluvial sand and mud of the low valley of the Vyatka. (Travels in Siberia, vol. i. p. 132, Amer. edit.) Malmish is in about the same latitude as Krasnojarsk; but is forty degrees of longitude farther to the west, where the climate is much milder. ↑ We are not aware that any specimen has been found south of 64°; and this was on the Wiljui, a tributary of the Lena. 508 lieve that the frozen earth of the more northern and eastern regions might have preserved for some vast period the carcasses of the mammoth and rhinoceros which are found there. The ice and frozen mud have undoubtedly been the agent which has contributed to preserve the flesh of these animals in Northeastern Siberia; but is it credible that even there these carcasses have rested without decay during the enormous periods demanded by the geologists? The We have pointed out elsewhere that the climate of Northern Russia and Siberia was formerly much less severe than it is at present.* fact that the mammoth was sustained in such large numbers is a testimony to the same effect. In a Report to the British Association, in 1869, on the subject of the extinction of the mammoth in Siberia, Mr. Howorth reaches Mr. Howorth on the extinction of the following conclusions. : the mammoth. 1. That the mammoth lived where its remains are found. 2. That a great portion of this area is now a moss-covered tundra, or an ice- and boulder-heap. 3. That no herbivore of the size and development of the mammoth could find subsistence in that area now. 4. That, although covered with wool, and therefore adapted to a more rigorous climate than that of India or Africa, neither the mammoth nor the rhinoceros could survive the present winter temperature of Northern Siberia. 5. That the remains of the food eaten by the mammoth, and found and examined by Middendorff and Brandt, are remains of plants only found now in more southern latitudes. Mr. Howorth concludes farther, therefore : That the climate and condition of things in Siberia have changed very greatly since the mammoth existed there. In support of this conclusion, he calls attention to the fact that the bed of the Arctic Sea north of Siberia is rapidly rising, and exposing banks of sand containing mammoth-remains, the land rapidly gaining on the sea along the whole coast-line. The appearance of the tundra, says Mr. Howorth, seems to point to a not very distant submergence of the whole of Siberia as far south as the highlands, which roughly mark the present northern limit of trees. What, then, has led to the extinction of the mammoth? The hand of man, says Mr. H., is quite inadequate; and we must seek for the cause in the draining of the vast mediterranean sea which once existed from the Euxine to the Klingar Mountains. The drainage of this sea *Chap. xxii. p. 380. See, also, "Matériaux pour l'Histoire de l'Homme," Décembre, 1872, p. 550. |
