GEOLOGICAL OBSERVATIONS IN SOUTH GEORGIA. 815 



general level as if the present rugged topography had been carved out of an ancient 

 pene-plane. In this denudation glaciers have no doubt played their part. The 

 photographs of King Edward's Cove (PI. LXXXVII, fig. 2) and other places show that 

 the country still contains numerous glaciers and extensive snowfields. The photo- 

 graphs, it should be remembered, were taken in the South Georgian summer. The 

 glaciers include great valley glaciers, and some of them flow down from high snow- 

 fields and reach the sea, as shown in the view of Royal Bay (PI. XC, fig. l). Beside 

 Cumberland Bay is a high-level glacier, from which one lobe flows down to the 

 lowland, but most of its discharge appears to be by avalanches which form a series 

 of recemented glaciers at the foot of the cliffs (PI. LXXXVII, fig. l). The effect of 

 the glaciers is well shown on many of the photographs. The sweeping away of the 

 decayed rock material has left many tarns, as near Tonsberg Point (PI. LXXXIV, 

 fig. 2), and the lateral erosion of the valley glaciers is shown by the spurless rock 

 walls in Royal Bay (PI. XC, fig. l). 



The former greater extension of the ice is also shown by the old moraines, as in 

 PI. LXXXIII, fig. 2. 



Frost shattering has obviously played a very active part in developing the 

 present topography. Some of the mountains rise into rock pinnacles, such as that 

 seen above Mai Viken Glen (PI. LXXXVI, fig. 1, and in PI. XC, fig. 2) ; these rough 

 crags must either be post-glacial or have stood in glacial times above the limit of the 

 ice. The recent but extensive talus screes (PI. XC, fig. 2) are probably also the 

 result of frost. Corries, which may be explained here as elsewhere by the shatter- 

 ing of rock walls by frost on the borders of sheets of snow and ice, can be recognised 

 in PL LXXXVIII, fig. 2, and PI. LXXXIX, fig. 2, as well as at Cape George. 



The photographs also show that in addition to the movements which have folded 

 the older rocks, South Georgia has been subject to many modern bradysismic move- 

 ments. The most important was a subsidence which has given the whole coast a 

 drowned topography, as shown in the photographs of Leith Harbour in PL LXXXIII, 

 fig. 1, and PL LXXXV, fig. 1. 



Some of the inlets of South Georgia have been described as fiords, and some of 

 those illustrated by Mr Ferguson's photographs belong to the category of fiords 

 (PL LXXXIII, fig. 1). 



The main subsidence has been succeeded by successive elevations, which have led 

 to the formation of raised rock platforms and beach lines. The highest of these is a 

 wide plain of marine denudation which is shown, for example, beside Leith Harbour in 

 PL LXXXIII, figs. 1 and 2 ; PL LXXXV, fig. 1. This rocky coast platform increases 

 the general resemblance of this South Georgian coast to that of parts of Norway. At 

 a lower level occurs another rocky shore platform, as around Leith Harbour. The 

 lowest and last elevation is indicated by the toe-like projections from the promon- 

 tories which are a characteristic feature of coasts that have undergone a small recent 

 uplift. These projections are well shown in a view of Stromness Bay (PL LXXXV, 



