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Human Origins

Chapter 8 GEOLOGY AND PAL ONTOLOGY.

Word Count: 9047    |    Released on: 06/12/2017

ecent or Post-Glacial Period-Lake-Villages-Bronze Age-Kitchen-Middens-Scandinavian Peat-mosses-Neolithic Remains comparatively Modern-Definition of Post-Glacial Period-Its Duration-Mellard Read's Esti

Periods-Antiquity measured by Changes of Land-Lyell's Estimate-Glacial Débris and Loess-Recent Erosion-Bournemou

ords, but these are no longer stately tombs and temples, massive pyramids and written inscriptions. Instead of these we have flint implements, incised bones,

gressive series from the oldest and rudest pal?olithic specimens, up to the highly-finished ones of polished stone, and through these into the age of metals, and into historic times and the actual implements of existing savage races. It is impossible to doubt that

y for 7000 years in Egypt, and certainly for 5000 and probably for 6000 or 7000 years in Chald?a. In each case we find populous cities, important temples and public works, writing and other advanced arts and industries, and all the signs of an old civiliz

honous, and attributed their arts, industries, and sciences to the inventions of native gods, or demi-gods, who reigned like mortal kings, in a remote and fabulous antiquity. We can gather nothing therefore from tradition that would enable us to add even 1000 years with certainty to the date of Menes; while from the high state of civilization which had been evolved prior to his accession, from the primitive conditions of the stone period whose r

ing fauna and flora, climate and configuration of seas and lands, have undergone no material change. It is characterized generally as the neolithic period, in which we find polished stone superseding the older and ruder forms of chipped stone, and passing itself into

lled the glacial period, for although the commencement, termination, and different phases of the two great glaciations and intermediate inter-glacial periods cannot be exactly defined, and hard-and-fast lines drawn between the later plioce

for the present purpose, for all is different, and even mammalian life is only known to be present in a few forms of small and feeble marsupials. Nor is it necessary to enter on any detailed consideration of the Eocene or earlier tertiary, for the types of mammalian life are so different from those of later periods, that it cannot be supposed that any animal so highly organized as man had then come into existence. The utmost we c

the Miocene, or to enter on any details of the later periods, except so far as they bear on what may be called geological chronology, i.e. on

s, or those of the present day in New Guinea. Some of these have been occupied continuously, so that the débris of different ages are stored in consecutive order like geological strata, and afford an unerring test of their relative antiquity. It is clear that many of those lake-villages were founded in the age of stone, and passed through that of bronze into the age of iron. The oldest settlements belong to the neolithic age, and contain polished stone

ing included from the first, and the horse only at a later period. Agriculture follows next in order, and considerable proficiency was attained, barley and wheat being staple articles of food, and apples, pears, and ot

shapes, supersedes stone and copper. For the most part these bronze implements seem to have been obtained by foreign commerce from the Ph?nicians, Etruscans, and other nations bordering on the Mediterranean, though in some cases they were cast on the spot from native or imported ores. The existence of bronze, however, must go back to a far greater antiquity than the time when the neolithic people of Europe obtained their first supplies f

pe, hardly carry us back to dates as remote as those furnished by the monuments of Egypt and Chald?a. Indeed, there are no facts certainly known to us from remains of the bronze ag

ng up since the villages were built with the known rate of silting up since Roman times. The calculations vary very much, and can only be taken as approximative; but the oldest dates assigned do not exceed 5000 b.c., and most of them are not m

e in Asia, and overran Europe in successive waves. On the contrary, all the evidence and all the best authorities point to their having occupied, when we first get traces of them, pretty much the same districts of the great plain of Northern Europe and Southern Russia as we now find

accumulation of shells of oysters, mussels, and other shell-fish, bones of wild animals, birds, and fish, all of existing species, with numerous implements of flint or bone, and occasional fragments of coarse pottery. They are decidedly

t be apparent when we consider that the state of civilization implies a very scanty population. It has been calculated that if the neolithic population of Denmark required as many square miles for its support as the similar existing populations of Greenland and Patagonia, their total number could not have exceeded 1000, and each mound must have been the accumulation of perhaps two or three families. Ancient, however, as these mounds must be, they are clearly neolithic. They are sharply distinguished from the far older remains of the pa

are all modern, those in the oak stratum are of the later neolithic and bronze ages, and those in the lowest, or fir-horizon, are earlier and ruder neolithic, resembling those found in the older lake-villages and shell-mounds. Now beech has been the characteristic forest tree of Denmark certainly since the Roman period, or for 2000 years, and no one can say for how much longer. If the speculations as to the origin of the Aryan race in Northern Europe are correct, it must have been for very much longer, as the word for beech is common to so many of the dialects into which the pr

y borings through the deposits of the Nile, are the oldest certain human relics of the neolithic age which have

thick; while below this, pal?olithic implements and a quaternary fauna occur in an upper stalagmite one to three feet thick, below it in red cave earth five to six feet thick; then in a lower stalagmite in places ten or twelve feet thick, and below it again in a breccia three or four feet thick. This is confirmed by the evidence of all the caves explored in all parts of the world, which uniformly show any neolithic remains confined to a superficial layer of a few inches with many feet of pal?olithic strata below them. And river-drifts in the same manner show neolithic

be a very decided break between the recent and the quaternary. The instances are rare and doubtful in which we can see any trace of the remains of pal?olithic man, and of the fauna of extinct animals, passing gradually into those of neolithic and recent times. Bu

onger intervals of time. In like manner, we cannot positively say when this post-glacial period ended and the recent began. Not, I should say, until the exceptional effects of the last great glacial period had finally disappeared, and the climate, geographical conditions, and fauna had assumed nearly or entirely the modern conditions in which we find them at the commencement of history. And this may have been different in different countries, for local conditions might make the glacial period commence sooner and continue later in some districts than in others. Thus in North America, where the glaciation was more intense, and the ice-cap extended some ten degrees further south than in Europe, it might well be that it was lat

y can only be obtained by defining its commencement with the first deposits which

eft the country buried in a thick mantle of boulder-clay and drift, such an amount of denudation, and such movements of elevation and depression have taken place, as must have required a grea

of oak rooted in the clays; this again must have subsided and let in the sea for a second time, which must have remained long enough to leave a large estuarine deposit, and finally the whole must have been raised to the present level before historical times. The phenomenon of the submerged forest is a very general one, being traced along almost all the sea-coasts of Western Europ

mencement of the post-glacial period. These calculations are disputed, but it seems certain that several multiples of the historical standard of say 10,000 years, must be required to measure the period since the glacial age finally disappeared, and the earth, with its existing fauna, climate, and geographical conditions, came fairly into view. This is confirmed by the great changes which have taken place in the distribution of land and water since the quaternary period. Huxley, in an article on the Aryan question, points out that in recent times four great separate bodies of water-the Black Sea, the Caspian, the Sea of Aral, and Lake Balkash-occupied the southern end of the vast plains which extend from the Arctic Sea to the highlands of the Balkan peninsula, of Asia Minor, of Persia

her rivers, such as that of the Mississippi at St. Paul's. The evidence is not conclusive, for it depends on the rate of erosion going on for the last twenty or thirty years, which may obviously give a different result from the true average, and in fact older estimates, based on longer periods, gave the rate adopted by Lyell. But if we admit the accuracy of the modern estimates, it does not affect the total duration of the glacial period, but simply that of a late phase of the post-glacial, when the ice-cap which covered North America to a depth often of 2000 or 3000 feet, had melted away and shrunk back 400 miles from its original southern boundary, so as to admit of the wate

ich the fronts of glaciers advance when forced by a mass of continental ice down fiords on a steep descending gradient, into a deep sea, where the front is floated off in icebergs, affords no clue as to that of an ice-cap spread, with a front of 1000 miles, over half

is much longer than that for which we have historical records, the glacial exceeds the post-glacial in a far higher proportion. The second, that throughout the whole of this glacial period, from it

nter on any detailed arguments, and the leading facts may be taken as established. It may be sufficient, therefore, if I give a short summary of those facts, and qu

iation. Ice-caps radiating from Scandinavia crept outwards, filling up the North Sea, crossing valleys and mountains, and covering with their boulders and moraines a wide circle, embracing Britain down to the Thames valley, Germany to the Hartz mountains,

the Mont Blanc range, at that height on the opposite range of the Jura. Nor is this a solitary instance. We find everywhere traces of enormous glaciers in the Pyrenees and Carpathians, the Atlas and Lebanon, the Taurus and Caucasus, the highlands of Scotland, Ireland, and Wales; in the Rocky Mountains and Sierra Ne

his land must have been more elevated than at present, so as to rise, like Greenland, far into the region of perpetual snow, where all rain falls and accumulates in the solid form; and also to supply the enormous mass of débris which the ice-caps and glaciers left behind them. It is not too much to say that a million of square miles in Europe, and more in North America, were covered by the débris of rocks ground down by these glaciers, and often to great depths. Most of the débris of the first glaciation have been removed by denudation, or ploughed out by the second gre

ch many changes took place in the geographical conditions and in the fauna and flora, requiring a very long time. Thus Britain, which had been reduced to an Arctic Archipelago, in which only a few of the highest mountain peaks emerged as frozen islands, became united to the continent, and the abode of a fauna consisting in great part of African animals. At one time boreal shells were deposited, at the bottom of an Arctic ocean, on what is now the top of Moel-Tryfen in Wales, a hill 1300 feet above the present sea-level; while at another the hippopotamus found its way, in some great river flowing from the south, as far north as Yorkshire, and the remains of African animals such as the hyena accumulated in our caves. In Southern France we had at one time a vegetation of the

tiquity. First, there is the amount of elevation and depression. We have seen that marine Arctic shells have been found on the top of Moel-Tryfen, 1300 feet above the present sea-level. Nor is this an isolated instance, for marine drifts apparently of the same character have been traced on the mountains of Scotland, Wales, and Ireland to a height of between 2000 and 3000 feet. In Norway, also, old sea beaches are found

e has been little or no perceptible change anywhere since the commencement of history, and the only accurate measurements of changes now going on are those made in Sweden, where it appears that in some cases elevation, and in others depression, is taking place at the rate of about two and a half feet in a cen

ring the process. And this only embraces part of the whole glacial period, for the depression did not begin until after the climax of the first great glaciation, when the land probably stood higher tha

han its present valley, which must have been since scooped out by sub-a?rial denudation. The rate of deposition of the Nile mud is about three inches per century, and there seems no reason why that of the fine glacial mud should have been more rapid, charged as the Nile is every year with mud from the torrential rains of the Abyssinian highlands. At this rate it would have required 320,000 years to accumulate the 800 feet of loess of the Rhine valley. Here again the rate may have been faster, but it is sufficient to show that an immense time must have elapsed, and the loess is a distinctly glacial deposit, containing pal?olithic human remains and a pleistocene fauna, and embracing only a portion of the quaternary period. Nor is it an isolated phenomenon confined to Europe, but is found over the whole world wherever rivers have flowed from regions which were formerly buried under ice and snow. It is found in great force in the valleys of the Yang-tse-Kang and the Mississippi, and Sir Charles Lyell, referring to the fossil human bone found in it at Natchez, says-"My reluctance in 1846 to rega

ul, the evidence would remain the same for the immense time required for such a deposit, and there is abundant proof in Europe, that human implemen

laciers, and carried down further by rivers issuing from them than the coarser débris, which, as we have seen, cover 1,000,000 square miles to an average depth of fifty fe

s and seas assumed substantially their present contours and levels. I will give one instance which, although comparatively modern, will come home readily to most British readers. Dr. Evan

rehend how immensely remote was the epoch when what is now that vast bay was high and dry land, and a long range of chalk downs, 600 feet above the sea, bounded the horizon on the south? And yet this must have been the sight that met the e

now going on. Nor can the action of ice or river floods be evoked to accelerate the process, for evidently it has throughout been a case of marine erosion. The only question is whether this dates back even into the later phases of the glacial period, for the opposite cliffs show no sign of having been either depressed beneath th

fessor Prestwich to institute an exhaustive inquiry as to these upland drifts; and the startling conclusion he arrives at is, that the oldest of them, or great southern drift, in which the implements are found, could only have come from a mountain range 2000 to 3000 feet high, which formerly ran from east to west in the line of the anticlinal axis which runs down the centre of the present Weald of Kent, between the north and south chalk-downs, and which has been since worn down to the present low forest-ridge by sub-a?rial denudation. The reasoning by which this inference is supported seems irresistible. The drift could not have been deposited by the present rivers or with the present configuration of the country, for it is found at levels 300 or 400 feet higher than the highest watersheds between the existing valleys. It consists not only of chalk flints, but to a great extent of cherts and sandstones, such as are found at present in the forest-ridge of the Wealden and nowhere else. It must have been brought by water, for the gravels are to a considerable exte

3000 years. At this rate the time required for the removal of 2000 feet of the Wealden ridge would be no less than 6,000,000 years; but of course this would be no fair test, as denudation would be vastly more rapid than the present average rate, on hill

r has traced over many of our southern counties. If this conclusion is correct, it solves the problem of tertiary man by showing numerous pal?olithic implements in a stage older than an undoubted Pliocene bed. The implements fou

hills, divided by steep ca?ons and by the valleys of the present great rivers. In one case, that of the Colombia river, this denudation has been carried down to a depth of over 2000 feet, and the river flows between precipitous cliffs of this height. The present gold-mining is carried on mainly by shafts and tunnels driven through superficial gravels and sheets of basalts and tuffs, to the gravels of the pre-glacial rivers, which are brought down in great masses by hydraulic jets. In a great number of these cases stone implements of undoubted human origin have been found at great depths under several successive sheets of basalts, tuffs, and gravels. Mr. Skertchly, an

er chapter, when dealing with the question of the

n the works of Lyell, Geikie, Evans, Boyd Dawkins, and other modern geolog

ay be made upon it by any of the kindred sciences. But it is to those we must look for any chance of even an approximate measurement in years or centuries, for geology and pal?ontology only show

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