722 GREAT SERPENTINE BELT OF NEW SOUTH WALES, Hi., 



low, anomalous birefringence, and is in grains 1 mm., or more, in 

 diameter. The elinozoisite has a less well-marked cleavage, and its 

 polarisation-tints pass zonally from low outer colours, to bright 

 second order tints, in the kernel of the grain. In addition, there 

 are large flakes of white mica, and, interstitially, large plates of fel- 

 spar, chiefly oligoclase and possibly some orthoclase. Large grains 

 of apatite are present in some amount, and there are a few grains 

 of sphene; a very little calcite is also present. The greenish 

 mineral, though in hand-specimen it suggests hornblende, is micro- 

 scopically without definite structure, consisting of aggregated 

 chlorite-spherulites. 



The origin of this rock is unknown; the only suggestion, at all 

 reasonable, seems to be, that it is a highly altered gabbro-pegma- 

 tite; but that is quite unproven. 



The statement, that glaucophane-schist occurs near Barraba, has 

 appeared in print. The specimen at first attributed to the Barraba 

 district, later was stated to some from Gilgai, near Inverell; and 

 the specimen was carefully described by Mr. H. P. White(48) as 

 from that locality. Mr. L. A. Cotton informs me, that he knows 

 of no locality, near Gilgai, where it might have occurred; and no 

 signs of such rocks were found near Barraba by me, though, mind- 

 ful of Ransome's discoveries in Angel Island(49) ) I carefully 

 searched the whole length of the serpentine-belt for glaucophane- 

 rock. Possibly it was brought by a miner from New Caledonia, at 

 the northern end of which, such rocks are abundant. 



BIBLIOGRAPHY; 

 Additional to References cited in Parts i. and ii. 



34. Geol. Survey of Great Britain. " The Geology of the Launceston and 



Tavistock District Sheet." Memoir 337, p. 63. 



35. Pratt, J. H., and Lewis, J. V. — " Corundum and Peridotites." Bull. 



Geol. Surv. North Carolina, No. 1, p. 30. 



36. Bonney, T. G., and Raisin, C. A. — "The Microscopical Structure of 



the Minerals forming Serpentine, and their Relation to its History." 

 Quart. Journ. Geol. Soc, 1905, pp.690-715. 



