80 " FAYALITE BASALT." 



consolidated quickly, and under little pressure. Sections 

 were taken from both the top and bottom of the flow 

 to determine if there was any difference in these two 

 regions, but the results were disappointing, and it would 

 clearly require a flow of much greater thickness to give 

 any distinct points of diff'erence in crystallisation due to 

 pressure. This rock appears to stand the influence of the 

 weather and sea, and little sign of decomposition was 

 noticed in any of the sections, though here and there, in 

 some of the more weathered sections, traces of some 

 chloritic mineral were seen. If occurring in larger flows 

 it would no doubt make a good stone for such purposes as 

 the foundations of buildings, road-metal, &c. 



Appended are two water-colour drawings of Sections — 

 No. 1. Low power ( x 50) showing (a) fayalite crystals ; 

 (b) apatite crystal. The relative proportions of Fayalite 

 and base are here shown. 



No. 2. Shows a fayalite crystal under a higher power 

 ( X 300). The small rod-like inclusions are here shown ; 

 also the character of the felspar microlite and magnetite 

 grains in the base. Both drawings are taken under 

 ordinary light. 



