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THE CONDITION OF INDIA, THE ASIATIC ISLANDS, AUSTRALIA, AND NEW ZEALAND DURING THE TERTIARY PERIOD.
In considering the geology of Europe, we have had to generalise with regard to a district, most parts of which have been mapped with at least sufficient accuracy to enable us to recognise the broad outline of the chief elevatory movements that have taken place, and concerning which we are provided with much minute and detailed knowledge of a positive kind. If, therefore, in spite of these advantages, there is still doubt and hesitation in determining the ancient history and the exact succession of deposits, it may well be supposed that not less difficulty exists with regard to other countries, of whose geological structure we know far less. This is the case with the great continent of Asia, in spite of numerous researches and the labours of many intelligent travellers; and, unfortunately, in many parts the most difficult of access, especially the Chinese empire, the investigations of these travellers have not included any accurate account of geological phenomena.
With a very few exceptions, the geology of Asia is known only with reference to distant and isolated spots; and this is the case, not perhaps from the want of continuity of such rocks at the surface, but because they are not readily traceable in the districts that
have been much visited, and are best developed in those which are least accessible to scientific travellers of the present day.
Generally speaking, however, the continent of Asia, like the greater part of Europe, must be considered as of recent elevation. The broad tracts north of the Himalaya chain, the district marked by the presence of extensive lakes on the European frontiers, a considerable part of the peninsula of India, and probably the whole of Arabia, besides many at least of the larger islands, are marked by the distinct presence of tertiary beds. These, however, exist in a somewhat different condition from that observed in Europe; they often contain fossil remains of animals totally different from European forms, but they still approximate, and offer many interesting analogies on a careful examination and comparison. It would be unsafe at present to suggest what may have been the actual history of the movements that formed the present continent, and the order in which they occurred, but we may at least give some sketch, which, however it may hereafter need modification, will suggest ideas and assist in the ultimate development of the subject.
If we look at the map of Asia, and compare its physical geography with that of Europe, it will not be difficult to trace the relation of the great mountain chains. The district, whose recent elevation in Europe is marked by the Alps and the Carpathians, is continued into Asia by the mountain chain of the Caucasus, and is thence traceable till we reach the Himalayas. Between these districts are spaces occupied by the Black Sea and the Caspian, where the land has probably only recently emerged from the sea.
Thus, then, it would appear that the elevatory movement has here acted at several places along a band extending for about eight thousand miles, with a breadth of nearly five hundred miles, and running nearly east and west. There is good reason to suppose that the whole of this tract, without exception, was under water at the commencement of the secondary period, for we find beds of lias and various other secondary deposits not only in the Alps and the Caucasus, but also in the western extremity of the Himalayas. The disturbance to whose action are due these two principal ranges of mountain country in the eastern hemisphere, was thus a recent occurrence, geologically speaking; and there is ground for supposing that the Carpathians and the Caucasus, which are intermediate ranges between the Alps and the Himalayas, became mountains at even a later date than the Alps.
But the study of Indian geology points still further, and teaches us that the Himalayan movement continued to a very recent period, for we find in the lower ranges on the flanks of this great chain a singular development of upraised and tertiary beds, apparently of various dates. We find, moreover, that the great tracts of country overspread by basalt, and appearing to have been only recently elevated, are really of very modern date, and were most likely among the results produced by that vast subterranean action, of which the forcing up, to the height of twenty-five thousand feet, the granite peaks of the mountain chain of central Asia was a direct and striking effect.
The chief localities in Asia which offer distinct and
satisfactory evidence on the subject of its ancient inhabitants, are first, the entire chain of the subHimalayas, or Sewalik hills; next the western coast of India, especially near the Gulf of Cambay; and, thirdly, the mouth of the great Irawaddi river, in the peninsula of Siam. These spots are widely distant, but the remains found in each have proved to belong to nearly or absolutely identical species. They are now at very different elevations, the difference amounting to many thousand feet, but they were no doubt formed contemporaneously, and at the same level. These beds are present under different circumstances, the material in which they are imbedded varying exceedingly; but they are essentially the same, and appear to have been deposited in a vast inland lake of fresh water, near whose banks there were forests, and in whose waters were present numerous fresh-water fishes.
The remains thus brought to light in the hard sandstone of the Sewalik hills, or in the conglomerate on the shores of the Gulf of Cambay, include a vast number of species, and must have been the result of accumulations made during a very long period, extending over as much of the tertiary epoch as is comprehended in the middle and newer divisions of other countries. They represent the inhabitants of the land during this period, and probably include nearly the whole series, since we find amongst them monkeys, numerous carnivorous animals, rodents or gnawing animals, Insectivora or insect-eating animals, and a most remarkable and unusual proportion of pachyderms, the prototypes of the numerous elephants, rhinoceroses, hippopotamuses, horses, &c., whose remains are found in various parts of the northern hemisphere.
There is besides a singular and interesting group of ruminants, including giraffes, antelopes, deer of various kinds, and many others more or less resembling the existing animals of the order. Some anomalous species are also met with, extremely different from existing forms; and, in addition to these mammals there are a number of reptiles, amongst which is a tortoise of the most portentous dimensions.
The detailed history of these animals, and the conclusions derived from the careful study of the numerous and perfect remains of them that have been obtained, have not yet been presented to the world by the naturalists best qualified to determine these matters, although the fossils have been the subject of careful study for a long time, and a magnificent work, in which they are described and figured, is now in course of publication.* The account given of them by myself, in a work published in the autumn of 1844,† is still the only general outline on record, and I am obliged therefore to repeat some portion of that in the present chapter.
Of the various animals whose remains are found in these Indian tertiaries, among the most striking, from its shape and proportions, was that designated "Sivatherium." This animal appears to have been as large as the rhinoceros. Its head was even larger in proportion, and was shaped like that of the elephant, being provided with a small trunk or proboscis; the eyes were small and sunk, the head very
* Fauna Antiqua Sivalensis. By Capt. Cautley and Dr. Falconer. + Ansted's Geology, Introductory, Descriptive and Practical, vol. ii. pp. 98 et seq.
From the Indian god Siva, an Onpiov (therion), a beast.