308 



PETROLOGICAL NOTES_, 



In the rocks from Eelah, the extent of intratelluric crystallisa- 

 tion, represented by the proportion of phenocrysts to ground- 

 mass, was moderately great in the basic members, greater in the 

 intermediate, and slight in the acid. In the basic rocks, centres 

 of crystallisation were few, but the crystals large; in the inter- 

 mediates, centres were numerous, but the crystals small. 



In conclusion, I wish to express my thanks to Professors 

 David and Woolnough for advice and assistance in my work. I 

 would also urge that the mapping already carried out in the 

 Clarencetown district (Jaquet, 1901) be extended to the Hud- 

 son's Peak-Eelah district, as much depends on the relation 

 between these two areas. The North Coast Railway should also 

 be traversed while the cuttings are yet fresh. Excellent sections 

 are exposed, especially around Paterson, and between Stroud 

 Road and Dingadee. 



LITERATURE. 



1913. Bbnson, W. N. — " The Geology and Petrology of the Great Serpen- 

 tine-Belt of New South Wales. Part i." Proc. Linn. Soc. N. S. 

 Wales, xxxviii., pp. 490-517; Part iii. Petrology. Ibid., xxxviii., 

 pp. 662-724. 



1911. Browne, W. R., & A. B. Walkom.— "The Geology of the eruptive 

 and associated rocks of Pokolbin, N.S. W." Journ. Proc. Roy. Soc. 

 N. S. Wales, xlv., pp. 379-408. 



1907. David, T. W. E.— " The Geology of the Hunter River Coal- 



Measures, New South Wales. Parti." Mem. Geol. Surv. N. S. 

 Wales, Geol. No. 4. 



1908. Harker, a.— Petrology for Students, 4th Ed. 



1909. The Natural History of Igneous Rocks. 



1911. Iddings, J. P.— Rock-Minerals, 2nd Ed. 



1901. Jaqukt, J. B.— "The Iron-Ore Deposits of New South Wales." 



Mem. Geol. Surv. N. S. Wales, Geol. No. 2, pp.62-84, Map (gives 



further references to the igneous rocks). 

 1901. Kyxaston, H. — " On some Tuflfs associated with the andesitic lavas 



of Lome." Trans. Edin. Geol. Soc, viii., pp.87-90.* 

 1883. LossEN, K. — "Ueber Porphyroide unter besonderer Beriicksichtigung 



der sogenannten Flaserporphyre in Westfalen und Nassau." Sitz- 



ungsber d. Ges. naturf. Freunde zu Berlin, No.9, pp. 154-178.t 



* Fide Harker. f Fide Roaenbusch. 



