71 



Journal of the Geological Society, 1907 — to which I am indebted for 

 many of the above facts — a new line of rails has been laid from 

 Downhead Quarry to Long Cross Bottom, and in one of the ex- 

 posures here made the long looked for Silurian strata was discovered, 

 Old Red Sandstone being first met with (quarter mile N.E. of Long 

 Cross Bottom) and conglomerate, whilst two hundred yards further 

 east a fine greenish sandy shale was found of undoubted Silurian 

 age, containing many fossils. There was no sign of tufT in this 

 exposure; it consisted of normal sediments. The fossils were of the 

 commoner Silurian types, moUusca such as Orthis, Lingula and 

 Spirifer, and a few fragments of trilobites, Calamene and Phacops, 

 also Crinoid stem joints. These have been identified as of Llan- 

 dovery age, and seeing that the Old Red Sandstone lies almost 

 directly on these beds, it seems evident tnat the Upper Wenlock and 

 Ludlow series of the Silurian age are here missing although in other 

 parts of England they occupy a considerable space between the two. 



I had the privelege of going over tnis area and examining the 

 exposures with Prof. Reynolds, and of hearing from his own lipS 

 the account of these interesting discoveries. This ground was 

 visited by some of us in an excursion in July last, and I was enabled 

 to explain the facts as we inspected the exposures. A good few 

 Silurian fossils were obtained by us from this recent cutting on that 

 occasion. Specimens of the other rocks, especially of the coarse 

 ashy conglomerate, collected by Mr. Sherring, have been exhibited 

 at the Society's rooms during the past summer. 



In conclusion one may point out the very extensive area 

 occupied by the trap and tuff in this district. The most interesting 

 deposit is undoubtedly the conglomerate, the origin ot w^hich it is 

 very difficult to ascertain. It has been conjectured that this material 

 forms the debris thrown out from the mouth of an active volcano 

 during the Silurian age, the crater of which may be represented by 

 part ot the area so occupied, whilst the adjacent trap is what 

 remains of the lava that flowed during its eruptions ; the tuffs were 

 formed by the volcanic ash blown around from the explosions. The 

 blockb in the conglomerate may possibly have been rounded by 

 friction in the vent of the volcano as they w^ere tossed up and down 

 during eruptions. The subject is a very attractive one, and although 

 this explanation has much in its favour, further observations are 

 necessary before the question can be finally decided. 



