The Story of the Hills: A Book About Mountains for General Readers.

by H. N. Hutchinson

Again, the ground of the Siberian toundras is to a large extent covered with a thin coating of sand and fine clay, exactly similar to that which is now deposited on the shores of the Frozen Ocean. In this clay, the remains of the mammoth, or woolly elephant, now extinct, are preserved in great numbers.

Parts of Northern Greenland have also risen; while at the southern end of this frozen land a downward movement is still taking place.

The best-known example of these slow movements within historic times is the so-called Temple of Serapis in the Bay of Baie, near Naples. The ruins of this building, which was probably a Roman bath, consist of a square floor paved with marble, showing that it possessed a magnificent central court. This court, when perfect, was covered with a roof supported by forty-six fine columns, some of marble, others of granite. There is still a hot spring behind, from which water was conducted through a marble channel. All the columns but three were nearly buried in the soil which covered the whole court, when the ruins were first discovered. Now, each of the three marble columns that are still standing shows clear evidence of having been depressed below the sea-level, for they all exhibit a circular row of little holes bored by a certain marine shell-fish, known as Lithodomus dactylus, at a height of twelve feet from the floor; each row is about eight feet broad. The shells may still be seen inside the little pear-shaped holes which the shell-fish bored for themselves; and the same shell-fish still live in the waters of the Mediterranean and bore holes in the limestone rocks.

It is therefore quite clear that these columns must have been under water to a depth of twenty feet or so, and also that they must have remained under water for some considerable time, during which the shell-fish made these borings. Then an upheaval took place whereby the whole building was elevated to its present level. But underneath the present floor, at a depth of five feet, were discovered the remains of an older floor. This probably belonged to an earlier building which had in like manner been depressed below sea-level. We thus learn that the land in this spot had been sinking for a long time, and that at some subsequent time it rose. The fallen columns suggest the idea that they were thrown down by earthquakes. At the present time the land here is again sinking at the rate of one inch in three or four years.

But the first example of upheaval within comparatively recent times, and one which is instructive as throwing some light on the subject of the present chapter,—namely, the upheaval of mountain-chains,—is to be found along the western mountainous coast of South America. Here we have the magnificent ranges of the Andes running along the whole length of this continent. The illustrious Charles Darwin, during his famous trip in the "Beagle," discovered numerous raised beaches along this coast, and at once perceived their importance to the geologist. The terraces are not quite horizontal, but rise towards the south. On the frontier of Bolivia, they are seen at heights of from sixty-five to eighty feet above sea-level; but nearer the higher mass of the Chilian Andes they are found at one thousand feet, and near Valparaiso, in Chili, at thirteen hundred feet above the sea. Darwin also discovered that some of the upheavals thus indicated took place during the human period; for he found in one of the terraces opposite Callao, in Peru, at a height of eighty feet, shells with bones of birds, ears of wheat, plaited reeds, and cotton thread, showing that men had lived on the terrace. These relics of human industry are exactly similar to those that are found in the huacas, or burial-places, of the ancient Peruvians. There can be no doubt that the island of San Lorenzo, and probably the whole of the coast in its neighbourhood, have risen eighty feet or more since the Red Man inhabited the country.

Callao probably forms the northern limit of the long strip of coast that has been upheaved, and the island of Chiloe the southern limit; but even thus the region of elevation has a length from north to south of about 2,480 miles.

We noticed in the case of Scandinavia that the upward movement is greater in the interior of the mountain-range than at or near the coast; and it is interesting to find that the same difference has been observed in the case of the Andes. The upheaving force, whatever its nature, acts with more energy under the Chilian Andes than under the rocks of the adjacent coast.

In New Zealand we have also evidences of upheaval; and if we trace out on the map a long line from the Friendly Isles and Fiji, through the Eastern Archipelago, and then on through the Philippine Islands, and finally to Japan and the Kurile Islands, we shall find scattered regions of elevation all along this great line, which is probably a mountain-chain, partly submerged, and along which numerous active volcanoes are situated.

Putting together all the evidence that has been gathered on this subject, of which only a very small part is here given, we are warranted in concluding that taking the world generally, regions where active volcanoes exist are generally regions where upheaval is taking place. There is also a very interesting connection between mountain-chains and lines of volcanic action. From this it seems to follow, if lines of volcanic action are also lines of upheaval, that mountain-chains are undergoing upheaval at the present time. This is a conclusion in favour of which a good deal may be said. It is certainly true in the cases of the Scandinavian range, and also of a very large part of the Andes, to which we have already referred. The Highlands of Scotland and Scandinavia form the northern end of an old line of volcanic action running down the Atlantic Ocean through the Azores, Madeira, Cape Verde Islands, Ascension, St. Helena, right down to Tristan d'Acunha.

In many other parts of the world we have evidences from submerged forests, the positions of certain landmarks with regard to the sea, and in some cases submerged towns, that movements of a downward nature are taking place.