inclusions. It is composed of tabulate plagioclase er\>t ;i !>, 

 large olivines, and granular titaniferons augite, with con- 

 siderable ilmenite. Long prisms of apatite are very abun- 

 dant. A striking feature of the rock is the occurrence of 

 ilmenite wrapping round plagioclase crystals. Along the 

 cracks in the olivine a peculiar mineral is forming. It is 

 brilliantly birefringent with a strong pleochroism in tints 

 ranging from a foxy-brown to yellow-green, and extinguish- 

 ing parallel to its length. This seems' almost certainly to 

 be iddingsite. On either side of the iddingsite is a narrow 

 green band possibly chlorite, and frequently this again is 

 bordered with quartz. A narrow streak of dusty carbonate 

 occupies the centre of the band. In the meshes of the 

 network of cracks the olivine is sometimes unaltered, 

 sometimes replaced by carbonates, sometimes by a felted 

 mass of interlacing fibrous amphilmlo, -.v\ iuolite and antho- 

 phyllite (?), somewhat resembling the pilite of Becke. That 

 this alteration is accompanied by expansion is indicated very 

 prettily in one spot by the bending outwards of the end of 

 a felspar lath that abuts on to the olivine crystal. Another 

 striking feature is the occurrence of beautifully spherulitic 

 chlorite. The order of crystallisation is peculiar ; appar- 

 ently it is as under :— 

 Apatite 1— I 

 Olivine I— I 



Augite 1- — | 



Plagioclase I 1 



Ilmenite I i 



Where basalt occurs in small veins in the rock it contains 

 a little biotite in small brown flakes. In a dolerite inclus- 

 ion from Dundas found in the collection of the Adelaide 

 University, hour-glass structure was observed in some of 

 the prismatic augites. 



The Breccia.— The breccia itself does not call for much 

 remark. On the circumference of the pipe it is exceedingly 



