1*8 THE ANTARCTIC. 



Bay there lies on the outside towards the coast, primary 

 clay slate alternating with layers of phyllite gneiss ; upon 

 this follows towards the south clay slate alternating with 

 quartz slate, and in the most southern points, near the 

 Weddell Glacier, huge yard-deep banks of shale or 

 (diabas) tufa and (diabas) breccia, as well as true sandstone, 

 occur. As is shown by the local distribution of these 

 various rocks, the highest parts of the island investigated 

 consist of the latest formations. This in itself is in no 

 way remarkable, but the moment attention is paid to the 

 stratification the whole aspect is changed. A more or 

 less inclined tilt, varying from 20° to jo° of the rocky- 

 strata towards the south-west, is everywhere apparent, 

 therefore counter to the major axis of the island ; the more 

 acute angles also are found on the coast, the obtuse ones 

 near the interior. This whole system of stratification 

 is crossed transversely by slate formations, and Hans 

 Thurach, the geologist of the expedition, concluded from 

 this, as well as from the fact that many of the layers 

 showed only semi-crystalline habitus, that the slates of 

 South Georgia are metamorphous, i.e., such as have 

 acquired their character through pressure. Fossils were 

 nowhere found on the island, and the presence of 

 amorphous carbon in microscopic flakes, as they have 

 been found in phyllite, primary clay slate, and quartzite, 

 is no sufficient proof of previous fossil remains. 



The structure of the south coast is not as yet under- 

 stood ; perhaps the island consists of a synclinal fold in 

 which the trough of the faults would represent the highest 

 ridge of the mountain range, and on the other side of the 

 ridge the same rocks would succeed each other in inverted 

 order ; perhaps, however, there is no structure of faults. 

 Whatever the facts may be, the investigations hitherto 

 made have been far too few to allow of even a sketch of 

 the geological origin of South Georgia ; one fact, however, 

 is certain, that important structural disturbances will have 



