MONIAN SYSTEM 0¥ EOCKS. 



539 









South-Stack 

 series of 

 Howth. 



td 



Dublin 

 Division. 









If 



.^2. 







O H 



1^ 



1 



cd" 





2.Jg 



<9 



If 



IS 



If 



Granite. 

 Ashy slates. 



1 





CD 









Granite and 

 eruptive rocks. 





TuAKTII DuLAS 



and east of 

 Parts Mountain. 



Grey 

 gneiss. 







o 



5^ 





it 



6 











1 ^ 



if- 



CD 





SI 



PI 



1? 











Granite 



and 



eruptive 



rocks. 









1 

 i 







So' ^ 



Q 



!^ 

 SI 



6 



It must not be left to wander in Archaean chaos, but as in former 

 days the " unfossiliferous greywacke " was made to deliver up, first 

 Siluria and then Cambria, so must the fragments below the Cam- 

 brian be gathered together into harmonious and consistent systems, 

 so soon as we can do it. 



It may, no doubt, be thought that we have too many such systems 

 abeady ; but this will obviously depend on the nature of the so-called 

 systems. Dr. Callaway, in describing these rocks of Anglesey, gives 

 them no new uame, but refers them to two distinct groups, the 

 Gneissic and the Slaty. These are descriptive names and are not 



