860 THE RENEWAL OF ANTARCTIC EXPLORATION. 



ill the Antarctic, facing the great Pacitic Ocean, there is a cliaiii of 

 active and extinct volcanic cones, rising in Mounts Erebus and Mel- 

 bourne to 12,000 and 15,000 feet, similar to, or rather a continuation of, 

 that vast chain of volcanoes which more or less completely surrounds 

 the whole Pacitic, facing, so to speaii, the circle of continental land 

 lof>king out on that great ocean basin. 



When we remember that tlicir ships were wholly uii]notected for ice, 

 the voyages of D'Urville and Wilkes to the Antarctic Circle south of 

 Australia must be regarded as plucky in the extreme. At Adelie Land 

 D'Urville passed through the vast tabular i(;ebergs and reached open 

 water within a few miles of the land, which at that point rose to a height 

 of 2,000 and 3,000 feet. Here the members of the expedition landed on 

 a small island about 000 yards from the maiidand. The rocks are 

 described as granite and gneiss, and from the description of their hard- 

 ness there can belittle d(>ul»t that the fundamental gneiss so character- 

 istic of continental land was here exi)osed. Wilkes was unable to reach 

 land, but in the same locality he found very sliallow water, and landed 

 on an iceberg covered with clay, nnid, gravel, stones, and large boulders 

 of red sandstone and basalt, 5 or G feet in diameter. 



There is another way in which a great deal may be learned concerning 

 the nature of Antarctic land. During the Challe)ujer expedition, trans- 

 ported fragments of continental rocks were never found toward the 

 central iiortions of the great ocean basins m tropical and sub-tropical 

 regions. The only rocks dredged from these areas were fragments of 

 pumice or angular rock fragments of volcanic origin. In the Cen- 

 tral Pacific, however, as the fortieth parallel of south latitude was 

 approached — thereforejust beyond the limit to which Antarctic icebergs 

 have been observed to drift — a few rounded fragments of granite and 

 quartz were dredged from the bottom of the sea; similar fragments 

 were obtained in the South Atlantic in high latitndes, and as the Clial- 

 lenger proceeded toward the Antarctic Circle in the South Indian Ocean 

 these fragments of continental rocks increased in number till, at the 

 most southerly i>oints reached, they, along with the mineral particles 

 and muddy matter derived from continental land, nmde n\) by far the 

 larger part of the deposit. These fragments consisted of granites, 

 quartziferous diorites, schistoid diorites, amphibolites, mica schists, 

 grained quartzites, sandstone, a few fragments of compact limestone, 

 and partially decomposed earthly shales. These lithological types are 

 distinctly indicative of continental land, and remembering what has 

 just been said as to their distribution, it seems Avholly unnecessary to 

 refute the suggestion that these fragments may have been transported 

 from the northern continents. 



erous wood. All these genera have a wide distribution in time, and consequently 

 tell little as to the ago of the fossils; but some of the shells present so close a reseui- 

 blanoe tospecies known to occur in Lower Tertiury beds in Britain, and to others of 

 about the same age, reconlcd by I);n\vin and Haker, from Patagonia, r,s to make it 

 highly probnblc that tlu'sc Antarctic fossils are likewise of Lower Tertiary age. 



