U. Silurian and Old Red in 8. Staffordshire. 489 



basset edges of, and then creeping up a small cliff composed of the 

 Downton Sandstones. The strike of this little cliff is S.S.E. to N.N.W. 

 A few yards away from the cliff the dip of the conglomerate and grits 

 is 10° and of the underlying Downton Sandstones 30°. One immense 

 pebble in the conglomerate is 36 by 18 by 18 inches. These 

 observations confirm Mr. Jukes' views as to these deposits.' These 

 basal rocks have been examined between the Lye on the south and 

 Sedgiey and Dudley on the north. The conglomerates are most 

 persistent and coarsest to the south. The pebbles chiefly consist 

 of quai'tzites, some of which are like the Cambrian quartzite that 

 occurs in situ 5-|- miles to the south-east of Lye at the Lickey. 

 Pebbles of Llandovery Sandstone {Pe7itamerus ohlongus), Silurian 

 limestone, a clay ironstone nodule in which Dr. Arber has kindly 

 identified Neuropteris, and pieces of coal also occur. 



COMPAEISON WITH THE LuDLOW DlSTMCT. 



"We wish to acknowledge the assistance that we have derived from 

 Miss Elles' and Miss Slater's description of the uppermost Silurian of 

 the Ludlow district, which, is 28 miles W.S.W. of Saltwells.- 



Their classifications, to a large extent, can be applied to South 

 Staffordshire, but if one attempts, in the latter area, to adhere too 

 closely to their palseontological zones, then difficulties arise, for 

 certain fossils reach higher horizons in South Staffordshire than 

 those recorded in Shropshire. 



Mr. King examined the sections between. Bow Bridge and the Mill 

 Race, Downton, after we had nearly completed our work, and had 

 previously examined the Whitcliff sections. 



The Aymestry and Upper Ludlow groups are in the Ludlow district 

 between 375 and 680 feet thick, whilst in South StajBFordshire they 

 are, say, 70 feet. The Upper Ludlow is 80 feet thick in the 

 Tortworth district.^ The flags and shales in B and C that are 

 so thick at Ludlow are extremely thin in South Staffoi-dshire, for 

 A, B, and C form practically one band of limestone with only very 

 thin partings. 



Zone A of Conchidium Knightii can be determined. Above this 

 zone our investigations, so far, only permit us to draw a line about 

 15-20 feet above the top of A, where we find the limestones are 

 disappearing, and the bulk of the rock is calcareous sandstones in 

 which Chonetes minima and sfriafaUa are very common. From this 

 point to the Ludlow Bone-bed we treat as D. Between Zones A and 

 D there is a zone where Dayia navicida is common, as at Ludlow. 

 Rhynchonella nucula is, in the limestone bands, very abundant up to 

 D*", and is of no utility in South Staffordshire for determining a zone. 

 D, though very much thinner than at Ludlow, does not differ to any 

 very marked extent, except that we cannot fix by Spirifera elevata 

 a zone D'', that R. nucula and 0, elegantula clearly ascend to D'' and 

 perhaps still higher, and that L. lata, which at Ludlow occurs in B, 



1 South Staffs Coalfields, 2nd ed., p. 80. 



2 Q.J.G.S., vol. Ixii, p. 195, 1896. 



^ Jukes-Browne's Historical Geology, 1st ed., p. 121. 



