Vol. 51,] CRUSH-CONGLOMERATES OF THE ISLE OF MAN. 



571 



In this locality many interesting variations of the structure may 

 be studied. Thus, in 



the craggy elbow on Fig. 4. — Part of crag on western side of 

 the western bank Sulby Glen, west of B. M. 137' 6". 



under the farmstead (Length= about 2 feet.) 



of Croit, the gritty 

 inclusions, admirably 

 displayed by weather- 

 ing, are widely 

 scattered, usually of 

 small size — not often 

 exceeding 2 inches in 

 diameter, and fre- 

 quently rounded as if 

 by actual rotation : 

 and the whole mass 

 is crossed by well-defined ' shear-cleavage,' oblique to the lie of the 

 ' pebbles.' This cleavage, which must, I think, be a structure of 



AAA. Bands of grit 1 to 3 inches thick, in sheared 

 slates ; cut, displaced, and lengthened by oblique 

 strain-slip y-y. 



The surface of the bands shows pseudo-ripple- 

 marking. 



rig. 



5. — Part of crag in Glen Dhoo, Ballaugh, on hillside S.E. 

 from Glen Dhoo Farm. (Length = about 2 feet.) 



AAA. Broken grit-bands in sheared slates, cut by strain-slip (y-y) and 

 the segments slightly rolled. 



Fig. 6. — Part of crag in Glen Dhoo, Ballaugh, western slope, 

 above ' T. Mill.' (Length = about 3 feet.) 



Sandy (A A) and slaty (B B) bands frayed out and obliterated in the crest of a 



ibid by shear-cleavage. 

 The shaly matrix of the crush-conglomerate has probably been similarly 



produced. 

 Note. — The localities indicated in figs. 2, 5, and 6 are not in the immediate 

 vicinity of the crush-conglomerate. These sketches were selected from those 

 contained in my notebook as convenient illustrations of the points dealt with. 

 Parallel cases could in every instance be found in the rocks bordering on the 

 crush-zones. 



