94 PROCEEDINGS OF THE COTTESW'OLD CLUB 



ascertained through the deep boring for coal at Signet, i^ 

 miles south of the Windrush at Burford, about 17 miles 

 north-west of Oxford, and about the same north of 

 Swindon. 



In this trial the following strata were penetrated (all but 

 the coal measures) : 



The Great Oolite and Forest Marble - 148 feet 



„ Lias and Rhaetic Beds - - 608 „ 



„ Red Marls - - - - 291 „ 



Red Sandstone - - - - i3'7 ,, 



Coal Measures and Coal Plants - 225 ,, 



1409 ,> 



The importance of deep boring is greatly exemplified by 

 the Burford or Signet trial, as illustrating the presence, 

 thickness, and thinning away of deeply seated strata, and 

 was little expected; proof, however, has been obtained of the 

 presence and thickness of the Triassic Rocks at the depth 

 of 1 184 feet, and the continuity of the Rhsetic and Lower 

 Lias at 608 feet, and the still deeper coal measures 

 ascertained, to be rich in coal plants, and thin coals below 

 the New Red Sandstone, or from 1184 feet to 1409 feet. 

 Possibly no spot could have been selected between the 

 northern escarpment of the Cotteswolds and Burford that 

 could have so well illustrated the thinning away of the 

 Inferior and Great Oolites and the scarcely expected 

 occurrence of the Triassic and Coal Measure Rocks in the 

 Upper Thames area. 



At Leckhampton, or a little east of the escarpment, the 

 thickness of the strata intervening between the base of the 

 Great Oolite and the base of the Lias is about 1200 feet, 

 but at Burford the total thickness is probably much under 



* I named all the specimens brought up during the progress of the boring, th.e coal 

 plants and shales being of much interest. 



