ON THE EXPLORATION OF- THE SETTLE CAVES. 167 



nizable rock, consists of a portion of the base of the Carboniferous Limestone, 

 which is a couglomerate of Silurian pebbles in a matrix of limestone, and 

 must have travelled at least two miles to its present position. Other bonlders 

 consist of Carboniferous Sandstone or Millstone-grit, but a very large propor- 

 tion are of Silurian rocks. 



In size they run from large blocks several tons in weight to mere sand- 

 grains, for the passage may be easUy observed. At one place you have 

 large boulders in a matrix of stony clay, then a clayey gravel, the component 

 stones wcU scratched and bruised as only glacial deposits are, then fine 

 gravel, still of the same character, shading off into sand. The sand again 

 gives place to laminated clay of the finest character. 



A very interesting section showing this has been lately uncovered ; it 

 lies at the back of the boulders, and contains several beds of laminated clay, 

 sand, and gravel intercalated with indisputable glacial deposits. 



This may be regarded as a positive proof that some at least of the lami- 

 nated clay is of glacial age and origin. 



In removing some of the boulders at the entrance, a step which the pro- 

 gress of the work necessitated, we appear at length to have come upon the 

 solid floor of the cave-mouth. "We found several long, wedge-like masses of 

 rock, with their apices upwards, sticking up from amongst the boulders. They 

 seem to run along definite lines, the spaces between which coincide with the 

 vertical joints traversing the roof and side of the cave. 



They stand up in pinnacles, and are not unlike in form similarly weathered 

 floors in other caves in Craven. "We may mention Browgill Cave near 

 Horton in Eibblesdale, which is now occupied by a stream. This peculiar 

 form seems to have arisen from the water working down along the joints 

 and slowly dissolving the limestone, leaving an edge projecting iipwards, in 

 some cases almost as shai-p as a knife. That the Victoria Cave was once a 

 stream-course there can be no doubt ; not only these limestone pinnacles, 

 but the peculiar weathering of the side of the cave at the entrance into a 

 succession of arched niches corresponding with the joints (another charac- 

 teristic of water caves) render this tolerably certain (see Plates Y. & VI. 

 and descriptions). 



And now, with the additional evidence of another year's diggings, we may 

 again consider the question (the most interesting perhaps of all the problems 

 before us) — Are the glacial deposits, which rest upon the older bone-beds 

 containing the extinct pleistocene mammals and man, in the position which 

 they occupied at the close of glacial conditions, or have they subsequently 

 fallen into their present site ? 



"We may again urge the reasons given last year, strengthened by enlarged 

 sections and a wider experience, which go to prove the first alternative. 



1. The cliff immediately above the cave is free from any boulder deposits 



for a considerable distance. 



2. The boulders lie at the base of all the talus, which must have been 



forming ever since glacial conditions declined, and no other falls of 

 even isolated boulders have occurred throughout the whole thickness 

 of talus. 



3. The boulders are so close beneath the cliif, that if aU the limestone 



which has fallen from it and is now lying on the boulders could be 

 restored to the cliff, it would project so much further forward, that the 

 fall of the boulders from the cliff to their present position would be 

 impossible. 



