516 A. C. RAMSAY AND J. GEIKIE ON 



upon the main limestone, and sometimes upon the overlying series 

 of shales. It would be better, indeed, to restrict the term breccia 

 to the true cave- and fissure-accumulations, leaving the term agglo- 

 merate for the great superficial masses which are at present under 

 review. At all events this is the arrangement we shall follow to 

 avoid confusion and obviate the necessity of frequent periphrases. 

 The old limestone-agglomerate, then, occurs, as we have said, in 

 greatest mass in the neighbourhood of the South Barracks, Iiosia, 

 and Buena Yista. In that area it attains a thickness in some 

 places of not less than 100 feet, and shows occasionally a well- 

 marked dip, as in the cliff south of the Naval Hospital, where the 

 inclination is towards the north-east at an angle of 18° ; as a rule, 

 however, the mass is quite amorphous and devoid of stratification. 

 The matrix is sometimes grey, sometimes reddish, and the included 

 fragments are almost invariably quite angular, no rounded water- 

 worn stones being visible. The agglomerate is of all degrees of 

 coarseness, the stones varying in size from mere grit up to blocks 

 12 feet and more in diameter* ; and larger and smaller fragments 

 are all rudely heaped together without the slightest reference 

 to size or shape, so as to present an appearance as tumultuous 

 and confused as that of a coarse volcanic agglomerate. 



It is a true superficial accumulation resting upon a broad irre- 

 gular surface of limestone and shale, its relation to the limestone 

 being well seen in the cliffs that overlook Camp Bay. The position 

 of the mass is shown in Sections IV. and V. The rock-surface 

 upon which it reposes appears to be somewhat uneven ; for whereas 

 the agglomerate merely caps the high limestone cliff's at Camp Bay, 

 it descends below the level of the sea at Rosia Bay. From the 

 rough and broken aspect presented by the agglomerate between the 

 Naval Hospital and Europa Pass, Mr. Smith supposed that a land- 

 slip had taken place there ; but beyond the rugged character of the 

 ground we could see no evidence of such a catastrophe. Indeed 

 it seemed to us that all the appearances might quite well be due 

 partly to sub aerial and partly to submarine erosion, as we shall 

 point out more particularly in the sequel. 



As we have already mentioned, there are other masses of super- 

 ficial agglomerate presenting the same general characteristics as the 

 great accumulation at Buena Yista ; but as these are clearly of later 

 date than the latter, we shall defer description of them to another 

 paragraph. 



There can be no doubt that the limestone- agglomerates owe their 

 origin more or less directly to subaerial forces. It is quite certain, 

 however, that these forces are not now acting with as much vigour 

 as at the time when the great masses of Buena Yista and Eosia 

 were accumulated. If they were, then the formation of the agglo- 

 merate should be still continuing, which is not the case. One 

 cannot but be struck with the appearance of great weathering 

 which the whole mass presents. Its surface is everywhere worn 

 and honeycombed, just like that of the main limestone itself. Nor 



* Some of the larger blocks must weigh 20 or SO tons at least. 



