Vol. 55.] LIMESTONE-KNOLLS IN CBAYEN. 347 



is seen exposed in a stream a few hundred yards east of Scaleber 

 Force, near Settle. Of this section, which is many yards in height, 

 Mr. Garwood wrote : — " On ascending the cliff close to the ' crush ' 

 I found a clear fault, and any amount of augen-structure and 

 ausweichungs-clivage. Besides the nodules I find that large 

 Productce have been rolled up into ' eyes ' in a similar way." The 

 outlines of the fragments in these breccias are also frequently 

 suggestive of partial solution. 



The third type of breccia, which was also formed in the sub- 

 merged part of the stream at Winterburn E-e&ervoir, is by far the 

 most suggestive of deposition, approaching in mauy respects a 

 conglomerate. Even here, however, the evidence for crush-breccia- 

 tioD is strong. The ' pebbles ' tend to run in irregular lines, which 

 are not straight, and thus one may find an irregular row of dark, 

 followed by another of lighter pebbles. In some of them central 

 fissures run part of the way through the fragment, as though this 

 were a portion of a small fold, and many of the fossils embedded in 

 the rock are much broken. 



The rock from the stream (Waygill) running into Winterburn 

 Reservoir shows in section very much the same characters as the 

 breccias which have been previously described. The suture-like 

 margins, due to solution under pressure, are very distinct, and the 

 matrix presents in places the schistose structure. Fragments of 

 chert enclosing: small spherical bodies are abundant. 



Fig. 13 (p. 348) represents the polished surface of a fragment 

 of this Winterburn breccia. 



On examining a polislied surface of another variety of the Win- 

 terburn breccia, the evidence for folding seems to me convincing. 

 The pebble-like masses in nearly every case show a central lenticular 

 portion filled with the matrix of the rock, which has here undergcme 

 somewhat more squeezing than it has outside these pebble-like 

 masses, but the fragments of crinoids are readily recognizable in it. 

 The indented surface of the inner portion of the 'pebble' against 

 this matrix is quite similar to that seen in the inner parts of loops 

 due to folding; this indented structure seems to be due to solution 

 when pressure was great. In some examples of the Winterburn 

 breccia, the lenticular portion is not isolated, but communicates with 

 the general matrix outside the ' pebble.' If these pebbly frag- 

 ments were ordinary epiclastic pebbles, I fail to see how the lenti- 

 cular mass of matrix in the interior can be accounted for, though 

 its evidence is completely in accord with the origin of the pebbles 

 as cataclastic structures. 



It will be noted that there is no great difference in the mode 

 of origin of the three kinds of breccia, and intermediate examples are 

 often found. As in the case of the knolls, so in that of the breccias, 

 we find structures analogous to those in the calcareous rocks, 



bottom corner. On the right of this is the folded limestone, which is thrown 

 into a number of complicated curves, oflen accompanied by small thiust-fauhs. 

 This causes the brecciated appearance of the rock, as seen m the figure. 



