Page:EB1911 - Volume 21.djvu/1004

Rh racing, half walking, half running, they reached 88° 23′ S. in 162° E at 9 a.m., the height above sea being 11,600 ft. The utmost had been done, though more food would have enabled the remaining 97 geographical miles to the South Pole to be accomplished. The camp was reached again at 3 p.m. The return journey of over 700 m. to the ship was one long nightmare of toil and suffering, but the length of the marches was unsurpassed in polar travel. Once and again all food was exhausted the day before the depot, on which the only hope of life depended, was picked up in the waste of snow Snow-blindness and dysentery made life almost unendurable, but, despite it all, the ship was reached on the 1st of March, and the geological specimens from the southernmost mountains, which prevented the sledges of the exhausted men being lightened as they went on, were safely secured. Never in the history of polar exploration had any traveller outdistanced his predecessor by so vast a step towards either Pole.

During the return journey of the “Nimrod” Shackleton was able to do a little piece of exploration to the south of the Balleny Islands, tracing the coast of the mainland for 50 m. to the south-west beyond Cape North, thus indicating that the Antarctic continent has not a straight coast-line running from Cape Adare to Wilkes Land. The British government contributed £20,000 to the expenses of the expedition in recognition of the great results obtained, and the king conferred a knighthood on the explorer, the first given for Antarctic exploration since the time of Sir James Clark Ross.

Captain R. F. Scott left England in the summer of 1910 with a new expedition in the “Terra Nova,” promoted by his own exertions, aided by a government grant, and with a carefully selected crew and a highly competent scientific staff. He intended to arrange for two parties, one leaving King Edward Land, the other McMurdo Sound, to converge on the South Pole. A German expedition under Lieut. Wilhelm Filchner was announced to leave early in 1911 with the hope of exploring inland from a base in the western part of Weddell Sea, and Dr W. S. Bruce has announced for the same year an expedition to the eastern part of Weddell Sea mainly for oceanographical exploration. It appears that the greatest extension of knowledge would now be obtained by a resolute attempt to cruise round the south polar area from east to west in the highest latitude which can be reached. This has never been attempted, and a modern Biscoe with steam power could not fail to make important discoveries on a westward circumnavigation.

Physiography of Antarctic Region.—In contrast to the Arctic region, the Antarctic is essentially a land area. It is almost certain that the South Pole lies on a great plateau, part of a land that must be larger and loftier than Greenland, and may probably be as large as Australia. This land area may be composed of two main masses, or of one continent and a great archipelago, but it can no longer be doubted that the whole is of continental character as regards its rocks, and that it is permanently massed into one surface with ice and snow, which in some parts at least unites lands separated by hundreds of miles of sea But all round the land-mass there is a ring of deep ocean cutting off the Antarctic region from all other land of the earth and setting it apart as a region by itself, more unlike the rest of the world than any continent or island. The expedition of the “Scotia” showed the great depth of the Weddell Sea area, and the attention paid to soundings on other expeditions—notably that of the “Belgica”—has defined the beginning of a continental shelf which it cannot be doubted slopes up to land not yet sighted In the Arctic region large areas within the Polar Circle belong to climatically temperate Europe, and to habitable lands of Asia and America; but in the Antarctic region extensive lands—Graham Land, Louis Philippe Land, Joinville Island and the Palmer archipelago outside the Polar Circle—partake of the typically polar character of the higher latitudes, and even the islands on the warmer side of the sixtieth parallel are of a sub-Antarctic nature, akin rather to lands of the frigid than to those of the temperate zone.

Geology.—Definite information as to the geology of Antarctic land is available from three areas—Graham Land and the archipelago to the north of it, Kaiser Wilhelm Land and Victoria Land. In the Graham Land region there seems to be a fundamental rock closely resembling the Archaean. Palaeozoic rocks have not been discovered so far in this region, although a graptolite fossil, probably of Ordovician age, shows that they occur in the South Orkneys. Mesozoic rocks have been found in various parts of the archipelago, a very rich Jurassic fossil flora of ferns, conifers and cycads having been studied by Nordenskjold, some of the genera found being represented also in the rocks of South America, South Africa, India and Australia. Cretaceous ammonites have also been found, and Tertiary fossils, both of land and of marine forms, bring the geological record down probably to Miocene times, the fauna including five genera of extinct penguins. Raised beaches show an emergence of the land in Quaternary times, and there is evidence of a recent glacial period when the inland ice on Graham Land was a thousand feet higher than it is now. The most prominent features of the scenery are due to eruptive rocks, which have been identified as belonging to the eruptive system of the Andes, suggesting a geologically recent connection between South America and the Antarctic lands. Volcanic activity is not yet extinct in the region.

As regards Kaiser Wilhelm Land, the Gaussberg is a volcanic cone mainly composed of leucite-basalt, but its slopes are strewn with erratics presumably transported from the south and these include gneiss, mica-schist and quartzite, apparently Archaean.

Much more is known as to the geology of Victoria Land, and the results are well summarized by Professor David and Mr Priestley of Sir Ernest Shackleton's expedition, whom we follow. From Cape North (71° S.) to 86° S. a grand mountain range runs south curving to south-eastward, where it vanishes into the unknown; it is built up of gneiss and granite, and of horizontal beds of sandstone and limestone capped with eruptive rock, the peaks rising to heights of 8000, 10,000 and even 15,000 feet, the total length of the range so far as known being at least 1100 miles. This range rises abruptly from the sea, or from the ice of the Great Barrier, and forms a slightly higher edge to a vast snow plateau which has been traversed for several hundred miles in various directions, and may for aught we know extend farther for a thousand miles or more. The accumulated snows of this plateau discharge by the hugest glaciers in the world down the valleys between the mountains. About 78° S. a group of volcanic islands, of which Ross Island, with the active Mt Erebus is the largest, rise from the sea in front of the range, and at the northern extremity the volcanic peaks of the Balleny Islands match them in height. The composition of the volcanic rocks is similar to that of the volcanic rocks of the southern part of New Zealand. The oldest rocks of Victoria Land are apparently banded gneiss and gneissic granite, which may be taken as Archaean. Older Palaeozoic rocks are represented by greenish grey slates from the sides of the Beardmore glacier and by radiolarian cherts; but the most widespread of the sedimentary rocks occurring in vast beds in the mountain faces is that named by Ferrar the Beacon sandstones, which in the far south Shackleton found to be banded with seams of shale and coal amongst which a fossil occurred which has been identified as coniferous wood and suggests that the place of the formation is Lower Carboniferous or perhaps Upper Devonian. No Mesozoic strata have been discovered, but deposits of peat derived from fungi and moss are now being accumulated in the fresh-water lakes of Ross Island, and raised beaches show a recent change of level. The coast-line appears to be of the Atlantic, not the Pacific type, and may owe its position and trend to a great fault, or series of faults, in the line of which the range of volcanoes, Mt Melbourne, Mt Erebus, and Mt Discovery, stand. Boulders of gneiss, quartzite and sandstone have been dredged at so many points between the Balleny Islands and the Weddell Sea that there can be no doubt of the existence of similar continental land along the whole of that side, at least within the Antarctic Circle.