60 J. W. Jackson & W. E. Alkins — Quartzose Conglomerate 



into thinly-bedded impure limestones with arenaceous layers and 

 lenticular beds of quartz-pebbles, dipping N.N.W. at an angle of 

 30°. Strong joints, at right-angles to these inclined beds, extended 

 downwards into the more massive conglomerate. 



The condition of the section rendered the relation of the 

 conglomerate and upper inclined beds to the massive light-grey 

 limestones (Productus humerosus-heds) of Caldon Low somewhat 

 doubtful. On the S.S.E side the conglomerate and inclined beds 

 appeared to overstep the truncated ends of the Humerosus-he&s 

 (which exhibited little or no dip), thus suggesting an unconformity 

 or a fault. At the opposite end of the section some inclined grey 

 limestones, in part crinoidal, had been left as a low ridge running 

 approximately W.S.W. to E.N.E., i.e at right-angles to the con- 

 glomerate section. These beds formed a small anticline near the 

 conglomerate, and may dip under it to the E.N.E. ; but this is not 

 certain. The relationship of these beds to the ITumerosus-'beds could 

 not be ascertained owing to the intervention of the quarry-platform. 



Judging from the specimens obtained the conglomerate appears to 

 consist mainly of water-worn pebbles of vein-quartz and quartzite, 

 about the size of hazel-nuts: many of these are green-coated. 

 Mixed with them are small pebbles of red jasper, black limestone, 

 chert, light-buff micaceous sandstone, purple volcanic ashes and 

 tuffs, etc., together with water-worn fragments of grey compact 

 limestone, sometimes of large size, the whole being cemented 

 together by a calcareous matrix. 



Numerous fossils, chiefly Brachiopods, were obtained from the 

 blocks of conglomerate lying in the quarry. The matrix in and 

 around these has a structure resembling oatmeal. Pebbles of 

 limestone, vein-quartz, fine grey oolite, and other rocks, are also 

 present. The peculiar "oatmeal" type of matrix is particularly 

 striking, and in section the structure is not unlike that of the 

 penecontemporaneously breeciated limestones figured by Professor 

 S. H. Reynolds and Dr. A. Vaughan from the Upper Seminula- zone 

 (S 2 ) of Burrington Coombe. 1 



The original source of the various pebbles is not easy to determine. 

 The fragments of grey compact limestones are undoubtedly of Lower 

 Carboniferous age, and the fact that they consist mostly of fairly 

 large pieces suggests that they had not travelled very far. The black 

 limestone, grey oolite, and chert, are also of Lower Carboniferous 

 age; these, however, are smaller and more worn, and may have 

 come from a greater distance. With regard to the vein-quartz, 

 quartzite, volcanic tuffs, ashes, etc., nothing very definite can be 

 said until further study and comparisons are made. The pebbles 

 of this series are well-rounded by wave-action, the majority being 

 no bigger than hazel-nuts. The included fossils comprise an 

 interesting series. They are mostly in the form of casts, but several 

 still retain the greater part of the shell. In most cases only single 

 valves are present. The imperfect state of preservation of some 

 specimens renders precise identification rather difficult, but careful 

 comparison with examples in our own collections and with figures 

 1 Q.J.G.S., vol. Ixvii, pi. xxviii, figs. 3 and 4, 1911. 



