246 H. S. Summers;: Cli/'vU <i/n<l Diabase Rochs. 



to sepai'ate thoin from the OrdoA-ician and Silurian rocks unless 



fossils a"" ..K+oir^orl oTifl f li <u niioistifm iif fVip. nvp-Orrlrivipinn 



age of tl 

 So fa] 

 charactej 

 as belons 

 of the d 



the vari' 



and that the chertj'' rocks are post-diabase and not necessarily 

 of the same age as one another, and consequently the cherts 

 may be pre-Ordovician in the Heathcote area, and Upper 

 Ordovician in the Tatong area. 



EXPLANATION OF PLATE IX. 

 Fig. L — Sketch Map of the Tatong District. 



