426 



NA TURE 



[March 3, 1898 



months stop short, at least, thirty degrees of latitude from the 

 south pole. 



These prevailing S.S.E. winds necessarily imply, as has been 

 shown in the case of the north' pole, the existence of a more or 

 less pronounced anticyclone overspreading Antarctica ; which in 

 its turn necessarily implies the existence of upper currents from 

 the northward, blowing towards and in upon the polar region 

 to make good the drain caused by the surface out-blowing south- 

 easterly winds. It may therefore be concluded that both the 

 surface winds and the upper aerial currents are diametrically 

 opposed to the requirements of this theory. 



What is now urgently called for is a well-equipped Antarctic 

 Expedition to make observations which will enable meteor- 

 ologists to settle definitely the distribution of atmospheric pres- 

 sure and the prevailing winds of this great region. Were this 

 done, the position in the Southern Ocean of the great ring of 

 lowest pressure that encircles the globe could be mapped out ; 

 and since it is towards this low-pressure ring that the wind- 

 driven surface currents of the ocean flow, a contribution would 

 thereby be made to oceanography, of an importance that cannot 

 be over-estimated, particularly as regards the great question of 

 oceanic circulation. 



Sir Archibald Geikie on Antarctic Geology. 



Hardly anything is yet known of the geology of the Ant- 

 arctic regions. By far the most important contributions to our 

 knowledge of the subject were made by the expedition under Sir 

 James Ross. But as he was unable to winter with his ships in 

 the higher latitudes, and could only here and there with difiiculty 

 eft'ect a landing on the coast, most of the geological information 

 brought home by him was gathered at a greater or less distance 

 from the land, with the aid of the telescope. Within the last 

 few years several sealing vessels have brought home some 

 additional scraps of intelligence, which only increase the desire 

 for fuller knowledge. 



As regards the land, merely its edges have here and there 

 been seen. Whether it is one great continent or a succession of 

 islands and archipelagos may possibly never be ascertained. We 

 know that in Victoria Land it terminates in a magnificent moun- 

 tain-range with peaks from 10,000 to 15,000 feet high ; but that 

 elsewhere it is probably comparatively low, shedding its ice-cap 

 in one vast sheet into the sea. 



The rocks that constitute the land are still practically unknown. 

 The dredgings of the Challenger Expedition brought up pieces of 

 granite, gneiss, and other continental rocks, and detritus of these 

 materials was observed to increase on the sea-floor southwards in 

 the direction of the Antarctic land. More recently several sealing 

 vessels have brought home from the islets of Graham Land to 

 the south of the South Shetlands pieces of different varieties of 

 granite, together with some volcanic rocks and fossiliferous lime- 

 stones. So far as these rocks have been studied, they do not 

 appear to differ from similar rocks all over the globe. The 

 granites have been found by Mr. Teall to be just such masses as 

 might have come from any old mountain group in Europe or 

 America. 



Among the specimens sent to me by Captain Robertson, of 

 the Active, from Joinville and Dundee Islands, which form the 

 northeastern termination of Graham Land, there was one 

 piece of reddish jasper which at once attracted my attention 

 from its resemblance to the " radiolarian cherts" now found to 

 be so widely distributed among the older Paloeozoic rocks, both 

 in the Old World and in the New. On closer examination, this 

 first impression was confirmed ; and a subsequent microscopic 

 study of thin slices of the stone, by Dr. Hinde, proved the un- 

 doubted presence of abundant radiolaria. The specimen was a 

 loose pebble picked up on the beach of Joinville Island. We 

 have no means of telling where it came from, or what is its geo- 

 logical age. But its close resemblance to the radiolarian cherts 

 so persistent in the Lower Silurian formations of the United 

 Kingdom, raises the question whether there are not present in 

 the Antarctic regions rocks of older Palaeozoic age. 



It would be of the utmost interest to discover such rocks in 

 situ, and to ascertain how far their fossils agree with those found 

 in deposits of similar antiquity in lower latitudes ; or whether, as 

 far back as early Palaeozoic time, any difference in climate had 

 begun to show itself between the polar and other regions of the 

 earth's surface. 



Among the specimens brought home by Dr. Donald and Captain 

 Larsen from Seymour Island, in the same region, are a few 

 containing some half-dozen species of fossil shells which have 



NO. 1479. VOL. 57] 



been named and described by Messrs. Sharman and Newton, 

 who suggest that they point to the existence of Lower Tertiary 

 rocks, one of the organisms resembling a form found in the old 

 Tertiary formations of Patagonia. Large well-developed shells of 

 Cuculhra and Cytherea undoubtedly indicate the former existence 

 of a far milder climate in these Antarctic seas than now prevails. 

 If a chance landing for a few hours on a bare islet could give 

 us these interesting glimpses into the geological past of the south 

 polar regions, what would not be gained by a more leisurely and 

 well-planned expedition ? 



But perhaps the geological domain that would be most sure to 

 gain largely from such exploration would be that which embraces 

 the wide and fascinating field of volcanic action. In the splendid 

 harvest of results brought home by Sir James Ross, one of the 

 most thrilling features was the discovery of a snowy volcanic 

 cone rising amid the universal snows of Victoria Land to a height 

 of more than 12,000 feet, and actively discharging "flame and 

 smoke," while other lofty cones near it indicated that they too 

 had once been in vigorous eruption. Ross landed on one or 

 two islands near that coast, and brought away some pieces of 

 volcanic rocks. 



If we glance at a terrestrial globe we can readily see that the 

 volcanic ring or " circle of fire," which nearly surrounds the vast 

 basin of the Pacific Ocean, is prolonged southwards into New 

 Zealand. The few observations that have been made in the 

 scattered islands further south show that the Auckland, Campbell, 

 and Macquarrie groups consist of, or at least include, materials of 

 volcanic origin. Still further south, along the same general line, 

 Mr. Borchgrevink has recently (1894-95) made known the ex- 

 tension of Ross's volcanic platorm northwards to Cape Adare, 

 the northern promontory of Victoria Land. He noticed there 

 the apparent intercalation of lava and ice, while bare snowless 

 peaks seemed still further to point to the continued activity of 

 the volcanic fires. Some specimens brought by his expedition 

 from Possession Island, were found by Mr. Teall to be highly 

 vesicular hornblende-basalt, while one from Cape Adare was a 

 nepheline-tephrite. This region is probably one of the most 

 interesting volcanic tracts on the face of the globe. Yet we can 

 hardly be said to know more of it than its mere existence. The 

 deeply interesting problems which it suggests cannot be worked 

 out by transitory voyagers. They must be attacked by observers 

 stationed on the spot. Ross thought that a winter station might 

 be established near the foot of Mount Erebus, and that the 

 interior could easily be traversed from there to the magnetic pole. 

 But it is not merely in Victoria Land that Antarctic volcanoes 

 may be studied. Looking again at the globe, we observe that 

 the American volcanic band is prolonged in a north and south 

 line down the western side of the southern continent. That it 

 has been continued into the chain of the South Shetlands and 

 Graham Land is proved by the occurrence there of old .sheets of 

 basalt, rising in terraces over each other, sometimes to a height 

 of more than 7000 feet above the sea. These denuded lavas may 

 be as old as those of our Western Isles, Faroe, Iceland, and 

 Greenland. But that volcanic activity is not extinct there has 

 recently been found by Captain Larsen, who came upon a group 

 of small volcanoes forming islets along the eastern coast-line of 

 Graham Land. It is tantalising to know no more about them. 



Another geological field where much fresh and important in- 

 formation might be obtained by Antarctic exploration is that of 

 ice and ice-action. Our northern hemisphere was once en- 

 veloped in snow and ice, and though for more than half a cen- 

 tury geologists have been studying the traces of the operations 

 of this ice-covering, they are still far from having cleared up all 

 the difficulties of the study. The Antarctic ice-cap is the largest 

 in the world. Its behaviour could probably be watched along 

 many parts of its margin, and this research would doubtless 

 aff"ord great help in the interpretation of the glaciation of the 

 northern hemisphere. 



To sum up : — Geologists would hail the organisation and 

 despatch of an Antarctic Expedition in the confident assurance 

 that it could not fail greatly to advance the interests of their 

 science. Among the questions which it would help to elucidate, 

 mention may be made of the following : — 



The nature of the rocks forming the land of the Antarctic region, 

 and how far these rocks contain evidence bearing on the history 

 of terrestrial climates. 



The extent to which the known fossiliferous formations of our 

 globe can be traced towards the poles ; the gaps which may occur 

 between these formations and the light which their study may be 

 able to throw on the evolution of terrestrial topography. 



