58 OUTLINES OF 11! I >GY 



rone to dt i-luToidal structure, each globular 



mass exfoliating into concentric onion-like coats (Fig. 6). 



-tone and dolomite project in <>oth, bleached 





FIG. 6. Dolerite (basalt) weathering .spbcroidally. N.jr.h (Juccnstcrry. 



knobs, curiously fretted, channelled, and honeycombed ; 

 the grass around is usually greener than elsewhere, and 

 the ground is often perforated with swallow-boles, tunnels, 

 and ramifying passages. 



The contrast between a weathered and a fresh piece of 



