76 PROCEEDINGS COTTESWOLD CLUB 1910 



The cause of this incoming of beds from south to north, 

 and their mutual relations, must be left to be discussed at 

 a later page (pp. 84-85), because it is first of all desirable to 

 mention what deposits immediately over- and under-lie the 

 Inferior-Oolite Series in the South Cotteswolds. 



The bottom-bed of the Inferior Oolite, and therefore that 

 which rests directly upon the Upper Lias over the southern 

 portion of the South Cotteswolds, is the Upper Trigonia-Gvit. 

 The deposit that occupies this basal position in the northern 

 portion is the A alensis-Bed, but it is usually ill-defined, and its 

 successor, the Opalinifoyme-Bed, or " hard cap to the Cephalo- 

 pod-Bed," as it is often colloquially called, is more readily 

 identified. 



The Series upon which the Inferior Oolite reposes is thus 

 divisible : 



(i) Marls, brown, ironshot, with impure limestones, forming the 

 Liassic portion of the Cephalopod-Bed. 



(2) Sands, yellow, with hard bands, and nodulc-shapcd masses called 



" burrs " (constituting the " Cotteswold Sands ") ; passing down 

 into 



(3) Clays, blue, with hard blue-grey limestone-bands resting upon the 



Marlstone of the Middle Lias. 



At the southern end of the South Cotteswolds there are 

 few exposures of these Upper Lias beds ; but at the northern 

 end many. The best are at Wotton-under-Edge. 



The Liassic clay (3) is mainly of fakifcri-bijrontis date. 

 The "Sands" (2) at the northern end of the district under 

 review are of Lilli-vanabilis date — pvc-striatuli, and at the 

 southern end mainly, if not wholly, post-sinatuH ; while in the 

 intervening district, near " The Springs," the striatulum-mwedM 

 comes in the Sands, which means that here their greater bulk 

 is of striatuli hemera (Sodbury Sands) . 



The Cephalopod-Bed is only well-exposed from Hawkes- 

 bury northwards, and is then best seen in the neighbourhood 

 of Wotton-under-Edge and Dursley. The hard cap to the 

 Cephalopod-Bed is of opaliniformis-d-dte, and, like the ill-defined 

 Aalensis-Bed that underlies it, belongs to the Inferior Oolite. 

 Therefore a more detailed account of it will be found at a later 

 page. Of the remaining component zones of the Cephalopod- 

 Bed, it may be pointed out that, with the aid of Mr S. S. 

 Buckman, the Styuckmanni-Bed has been indicated in most of 



