Vol. 59.] TOAECIAN OF BEEDON HILL. 449 



The division between sand and clay must not be regarded as 

 a definite horizon. The passage is to a certain extent gradual, and 

 in most cases is only shown by the spring-level, which again 

 is variable according to locality and to season. 



Nor must it be supposed that at the base of the Sands commence 

 the strata of the Lilli hemera. If this happen at one place, it may 

 not at another. The clay-level is known to rise higher northwards : 

 near Cheltenham Mr. L. Richardson found evidence of the strata of 

 Lilli hemera in so-called 'Upper Lias 7 clay 1 ; and eastwards, at 

 Chalford, clayey conditions and the water-level rise to the top of 

 the variahilis-beds. 



In the foregoing measurements one noticeable point is that the 

 Cotteswold Sands work out to a much greater thickness than had 

 been supposed, especially at Erocester Hill. 



To make just comparison between these localities and Bredon 

 Hill, not merely the Upper Lias Clay is to be taken, but the total 

 Toarcian deposits. Thus we get at Bredon (Toarcian) a thickness 

 said to be 380 feet, and these Cotteswold localities working out from 

 221 to 322 feet. Stinchcombe Hill may stand well enough for 

 Wotton. Instead of the Upper Lias at Wotton being 10 feet, 

 it should read as 220 feet to compare with Bredon's 380 feet. 



The Toarcian deposits do not maintain their full sequence from 

 Bredon Hill to the Frocester district of the Cotteswolds ; like other 

 Jurassic beds, they show evidence of anticlines and penecontem- 

 poraneous erosiou. At Standish Beacon there is non-sequence, by 

 erosion ipre-Dumortierice, post- variabilis — the effect perhaps of the 

 Birdlip anticline, noticeable in the Bajocian Denudation. 2 Towards 

 Birdlip the Cotteswold Sands thin considerably ; at or before 

 Birdlip they fail. What are mapped as Midford Sands (G 4) on the 

 Geological- Survey map in the district north of Birdlip, are not the 

 Toarcian or Cotteswold Sands, as to the south of that place, but 

 Aalenian Sands, the equivalent of the Northampton Sands — the strata 

 of the scissi hemera (G 5). And near Cheltenham these strata rest 

 directly upon clays of the date of Lilli hemera — 100 feet perhaps 

 of deposit as compared with Standish are gone ; but shales of Lilli 

 hemera are replaced by sands at Standish. 



At Bredon Hill the sequence is complete, or nearly so, again. 

 But Bredon, it may be noted, lies exactly in the line of the Cleeve- 

 Hill syncline, so conspicuous in connection with the Bajocian 

 Denudation. The persistence of synclines is here illustrated. A 

 small syncline formed in about Toarcian times saved the Toarcian 

 strata of Bredon Hill : a more pronounced syncline in Tertiary times 

 saved Bredon Hill itself. 



1 ' A fragment of a whorl of Lillia, most probably Lilli, was obtained from 

 a hard nodule embedded in clay, in the ridge connecting the spur of Wistley 

 Hill overlooking Vineyards Farm with the main hill-mass.' — L. .Richardson, 

 in litt. 



2 S. S. JBuckman, ' Bajocian & Contiguous Deposits in the North Cotteswolds 

 Quart. Journ. Geol. Soc. vol. lvii (1901) pi. vi. 



