﻿Vol. 6l.] OEDEK OE SUCCESSION OF THE MANX SLATES. 373 



comparatively-thin band of laminated sandy shale, or passage- 

 material, which in turn reposed on a thick mass of sandstone. 

 During the process of intense and complicated folding seen in the 

 area, the passage-beds, owing to their less-resisting nature, were 

 broken up and forced outward from the minor folds of the harder 

 grit. The easily -yielding mass of still softer shale in front greatly 

 facilitated this process, and many fragments of the passage-beds 

 were forced into this shale. 



Prof. Watts pointed out some of the difficulties presented by the 

 field-work in such a district as that in question. His microscopic 

 investigation of the rocks collected by Mr. Lamplugh, showed that 

 the individual pebbles were often beginning to exhibit a crush- 

 structure which was undistinguishable from the general structure 

 of the conglomerate. Further, he had been unable, after con- 

 siderable search, to discover in the conglomerate any rock-fragment 

 of a type different from the grits and slates found in immediate 

 contact with the conglomerate itself. 



Mr. Clement Reid thought, as the result of his recent examination 

 of the Ordovician rocks in Cornwall, that true conglomerates (though 

 sheared) could be distinguished from crush-breccias, if the softer 

 material was ignored, and attention concentrated upon the frag- 

 ments of whatever rock was hardest. In a sheared conglomerate 

 the hardest pebbles still remained as pebbles, the softer material 

 flowing past them ; in a crush-breccia the hardest fragments, on 

 the contrary, were the most angular, especially if they were rare. 



The Atjthoe thanked the Eellows present for their reception of his 

 paper, and the various speakers for their remarks. His friend 

 Mr. Lamplugh spoke of the Lonan-Flag Series as occurring both 

 below and above, which was, of course, different from his experience, 

 and hard in any case to explain. Prof. Watts spoke of the frag- 

 ments composing the Breccia as being broken up — • which they very 

 often were, as was natural ; but this did not affect their original 

 character. 



Q. J. G. S. No. 242. 2 p 



