rsr THE SUJJMEEGED PUREST OF TORE AY. 



13 



they have travelled to their present position along slopes which 

 are, for the most part, so slight that it is difficult to suppose existing 

 natural agencies to have heen concerned in their transportation. 



This breccia is, in all probability, an example of those deposits 

 which, going by the name of " head " in the west of England, 

 attain a great development in the maritime districts of Southern 

 England and Northern France, and which Sir A. Eamsay and Prof. 

 James Geikie have considered to be the equivalents of true glacial 

 deposits, such as the till, but formed in districts which were not 

 covered by the continental ice- sheets. 



That the clay bed, which thus rests either upon the Trias rock or 

 the breccia which caps it, forms the soil in which a portion of the 

 submerged forest of Torbay is rooted, there is no sort of doubt. It 

 is crowded with roots of all sizes ; while here and there, the 

 trunks of trees, whose roots branch through the clay in all direc- 

 tions, still stand erect and show themselves above the surface of 

 the shingle whenever this is thinly strewn over the tidal strand. 

 It is further covered, as shown on the map, with a mass of so-called 

 peat, D (fig. 2), which is nearly three feet thick in some places. 



Towards the end of December 1883, the sea exposed the area of 

 clay and underlying " head " shown at E, fig. 2. E itself represents 

 the trunk of a large tree about whose roots, which were partially 

 denuded, the clay was several feet thick, and whence it thinned 

 away to a feather-edge where it met the " head." Here, resting 

 immediately upon the breccia at G, two pavement-like aggregations of 

 stones were observed, each about two feet across, and of irregular out- 

 line, but both presenting the appearance of having once been united. 

 These quasi floor-fragments consisted of well-rolled beach stones, the 

 counterparts of certain trap pebbles, derived from the Trias, and very 

 numerous on the present beach, but differing totally in character 

 from the angular Devonian stones in the "head" on which they 

 lay. That these were no heaps of pebbles shot down from a cart 

 for some purpose, during a previous exposure of the breccia, as 

 might well have seemed the case^ was clear from the fact of their 

 being everywhere interpenetrated by fibrils of the forest roots. 

 A close examination revealed the curious fact that these trap 

 pebbles were all cracked and traversed in every direction by minute 

 fissures, so that the stones, usually difficult to break, even with a 

 heavy hammer, could be pulled apart by hand. The fractures 

 were of such a kind as forcibly to suggest that the stones had been 

 heated ; and some trap pebbles from the beach, upon being placed in 

 the fire, soon exhibited similar fissures, and became cracked in 

 exactly the same way as those forming the heaps in question. The 

 interstices of the hearth, as the structure now began to be con- 

 sidered, were crowded with fragments of charcoal, easily distinguish- 

 able from the dark-coloured and decomposed vegetable matter 

 furnished by the adherent rootlets. 



But if the seeming floor were really a hearth, the question at 

 once arose — Why should its builders have gone afield for materials 

 when there was plenty of Devonian sandstones ready to hand in the 



