VOL. XVII. (2) INFERIOR OOLITE -CHIPPING NORTON 



209 



Thickness in ft. ins. 



■7 "O 



O { 





21 r = 2 of Hook-Norton Section, p. 213]. Plant- 

 Bed Limestone, perforated with tubular 

 holes, into which black clay has infiltrated : 



I ft. 6 ins. to 2 ft. 8 ins 



2ia. Clay, tough: o to 2 ins. : average.. ■• 



1 22 Limestones, fine-grained, siliceous, fawn- 

 coloured, but blue-hearted, with numerous 

 fragments of black lignite : according to 

 I Waiford 2 to 8 ft. thick . . 



r 2^ FBed i2of HookNortonl. Trigoma-signata- 

 Bed of Waiford, the " Old Man of the 

 quarrymen. This bed is a fawn-coloured, 

 I blue-hearted limestone, joined on to the 



bed above ; Tngowja spp. abundant, ilie 

 I bed is extremely hard . . • • • • 



) 24a. Limestone, fine-grained, siliceous, blue, 

 weathering brown, with numerous frag- 

 ments of lignite . . • • • • . • • 

 b Conspicuous layer of ironstone : o to 4 ms. 

 c Limestone, similar to 24a. but more ferrugi- 

 nous : seen 2 ft, but according to Waiford 



{The following beds, not exposed at the time of my visit, 

 have been noted by Mr Waiford). 



" Rubbly, earthy limestone with nodules , 

 Gervillia pralonga, Trigoniasp.,T. producta, 

 Gresslya abducta, Avicula braambunensts, 

 Lima ovalis. Thickness not determined. 

 Compact, fine-grained yellow limestone 

 with yellow sand at base (thickness not 

 determined.)" 



25- 



26. 



It is important to obtain first a general idea of this fine 

 section, and then to investigate its many beds m detail. 



It should be first of all noticed that there are groups of 

 various-coloured clays near the top of the section and im- 

 mediately above the Swerford Beds. The deposits in between 

 are principally hmestones, all of which, Exelissa-Umtsion^, 

 Astarte-^ed. and Lower and Upper Nmn^a-Beds, are important^ 

 Scarcely less so are the associated deposits, the P^ma-Bed and 

 Cyathopora-hourgeti-B&^. 



The Upper iVmw^a-Bed varies considerably as regards 

 lithic structure. In places it is a hard limestone, in others 

 a marl. 



Previous to the deposition of the Viviparus-U^x\, there 

 was an erosion. The non-sequential relation of the purplish 

 Viviparus-^l2.x\ to the whitish Upper Nennaea-Bed (m its 

 marly condition) is very obvious. 



