THE GEOLOGY OE TYTHERINGTON AND GROVESEND. 7 



Beyond the fault the Basement Beds of the Trias lie in 

 a gentle dip. About 525 feet from the beginning of the 

 section the Palaeozoic beds rise unconformably beneath them, 



i^ig. 1. 



Sketch Section to show Mountain Limestone thrust up over Basement 

 Bed of Keuper by reversed fault. 



a a, Marly Limestone; b b, Yellowish White Marl; cc, Mountain 

 Limestone. 



and come to surface about 60 feet from the 5|-mile post^ 

 the Triassic beds here dying out at surface, and not reaching 

 as far as the tunnel mouth, as shown in Mr. Meredith's 

 section. Soon after the Palaeozoics come in, there is, 

 beneath the marty limestones of the Basement Beds, a 

 pocket of marl, described by Mr. Winwood, and specially 

 figured as " sand " by Mr. Meredith. Of the Basement Beds 

 of the Trias I shall speak again under that head (p. 14). 



Sub-section 3. — This includes the Palaeozoic beds from 

 where they appear beneath the Trias to the oolitic limestone 



