r 172 



Benarth Flags 

 and 



Grits. 



Upper flags & thin grits. 



Fine shales. 



Massive grits. 



Lower flags & thin grits. 



Sandy shales. 



Calcareous flags, with con. 



! Zone of CyrtograpAus 

 I symmetricus. 



! Zone of Monograptus 

 i riccartonensis. 



Zone of Cyrtograptus 



murcJiisoni. 



3 * 



Gyffin Shales 

 (300 feet). 



Conway Castle Grits 

 (150 feet). 



Deganwy Mudstones 



(Phacops-M.i\&- 



stones) 



(80 feet). 



Bodeidda Mudstones 

 (Trinucleus- Mud- 

 stones) 

 (350 feet). 



Cadnant Shales 



(Bier a no graptus 



Shales) 



(310 feet). 



Upper or Coetmor 



Ash-Group 



(thickness very 



variable). 



Upper Brecciated 

 Lava- Group 



(710 feet). 



Lower or Bodlondeh 

 A s li - G r o u p 



(60 feet). 



Lower Banded Lai 

 Group 

 (1400 feet). 



Light - coloured flaggy 7 Zone of Monograptus 



shales, with black bands. $ crenulatus. 

 Light-coloured shales. 



"| Zone of Monograptus 

 crispus. 

 Light-coloured shales, with ! Zone of Bastrites 

 black bands. | maximus. 



\ Zone of Monograptus 

 J sedgwicki. 

 Grey shales, with soft black > Zone of Monograptus 



mudstone-bands. ) gregarius. 



Blue-grey iron-stained flags,1 ^ f Mesograftus 



with softer shaly bands. V modestus _ 

 Massive calcareous grits.J 

 with shale-bands. 



""] Zone of Tlmcops (Bal- 

 ! mannites) mucrona- 

 f tus and Dicello- 

 J graptus anceps. 



Blue -grey shales and 

 calcareous mudstones. 



Blue - grey and 

 mudstones, 

 fossiliferous bands. 



with 



p 



P r 



sh f Shivery black shales, with 

 a J a thin ash-baud. 



P I Black ' blocky ' shales. 

 Hard flaggy shales. 



}■ TrinucJ eus-Bcds. 



Zone of Bicrano- 

 5 gaptus clingani. 

 \ Zone of Climaeo- 

 ) graptus wilsoni (?) . 

 ~] Zone of Bicranograp- 

 [ tus brevicaulis and 

 [ Mesograptus multi- 

 J dens. 

 i Flags and shales, with sili- 7 Zone of Climacograp- 

 (^ ceous ashy bands. ) tus peltifer. 



Coarse shahy ashes. 

 Mudstone-band, with Lingulce. 

 Siliceous ashy grits. 

 Mudstone-band. 

 Brecciated rhyolite. 

 Siliceous ashy grits, with 



nodular rhyolite. 

 Pale creamy rhyolites, with 

 conspicuous flow-brecciation 

 and two well-marked nodular 

 bands near the summit and 

 the base. 

 Coarse and fine ashes and ashy 

 shales, with a shale-band 

 containing G-lyptograptus 

 teretiusculus. 

 Lia;ht-grey and greenish-grey 



rhyolites (?). 

 Dark-grey banded rhyolites (?). 

 Pale-grey banded rhyolites (?). 



[The stated thicknesses are approximate only.] 



