Vol. 69.] PETR0L0G5T OF THE KALGOOELIE GOLDEIELD. 



645 



The presence of micropegrnatite in the amphibolites of Western 

 Australia was first pointed out by Dr. Vogelsang 1 in a rock from 

 the Murchison district in 1897, but the inference that the rock 

 was a derivative of a quartz-dolerite or a quartz-gabbro was not 

 definitely drawn. Similar rocks are of very common occurrence 

 in the Western Australian goldfields, but have generally been 

 classed by the Survey officers as quartz-diorites, despite their basic 

 nature. In 1909 I described several in detail as uralitized and 

 saussuritized quartz-clolerites and quartz-hornblende-dolerites 2 

 (GhS.M. 6407, 6432, 6443, 6483, & 6484). 



Analyses of Quartz-Dolerites and Quartz-Dolerite-Aimpiiibolites 

 from Western Australia. 





XVII. XVIII. 



XIX. 



XX. 



XXI. 



SiOo 



48-86 

 14-91 

 11-13 



49-42 

 1-95 



14-95 

 1-38 



10-76 

 0-47 

 6-16 

 9-85 

 2-70 

 0-72 

 0-77 

 0-09 

 0-55 

 none 

 0-26 



52-70 

 0-83 



1427 

 1-48 



11-07 

 0-18 

 6-39 

 8-23 

 315 

 0-23 

 0-12 

 024 



0-15 

 0-49 



52-31 



0-41 

 14-64 

 3-09 

 5-87 

 0-29 

 8-90 

 932 

 2-57 

 0-59 

 0-88 

 025 

 031 

 0-05 

 0-02 



5193 

 1-75 



14-26 

 2-49 



10-76 

 057 

 5-28 

 7-89 

 2-79 

 0-81 

 1-13 

 0-09 

 031 

 none 

 0-15 



Ti0 2 



AloO) 



Fe 2 3 



FeO 



MnO 



0-90 

 7-65 

 12-19 

 2-58 

 0-19 

 1-51 

 004 



none 



MgO . 



CaO 



NaoO 



K 2 6 



HoO+ 



H s O- 



P 2 5 



COo 



FeSo 



Totals 



Sp.gr 



Analyst ... j 



100-18 



100-03 



99-53 



99-50 



100-21 



3-08 



C. C. 



Williams. 



3-01 



E. S. 

 Simpson. 



2-96 



(?) C. G. 

 Gibson. 



3-00 



E. S. 

 Simpson. 



3-00 



E. S. 

 Simpson. 



XVII. Quartz-dolerite-amphibolite. G.S.M. 3231, Star of Colac G.M.L. 2872 E., 

 Kalgoorlie. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 67. 

 XVIII. Fresh quartz-dolerite. G.S.M. 7728, Irregully Creek, Asliburton Goldfield. 

 Ibid. No. 33 (1909) p. 164. 

 XIX. Quartz-dolerite-amphibolite. G.S.M. 5631, G.M.L. 375, near Greenmount 

 G.M., Southern Cross. Ibid. No. 17 (1904) p. 20. 

 XX. Quartz-dolerite-amphibolite. G.S.M. 6858, Red, White, & Blue G.M.L. 745, 

 Cue. Ibid. No. 29, pt. 2 (1907) p. 53. 

 XXI. Fresh quartz-dolerite. G.S.M. 7616, Secret Creek, Asliburton River. Ibid. 

 No. 33 (1909) p. 164. 



Pegmatitic Varieties of Quartz-Dolerite- 

 Amphibolites. 

 These rocks are found in Kalgoorlie at various places along the 

 •main band of quartz-dolerite-amphibolite, particularly on the west 



1 In K. Schmeisser, ' Die Goldfelder Australasiens ' Berlin, 1897, p. 44. 

 English translation by H. Louis, London, 1898, p. 63. 



2 Bull. Geol. Surv. W. Austral. No. 33 (1909) pp. 136-37, 144-45, 150-51, 

 ,& 155-56 ; also figs. 52 & 54. 



Q. J. G. S. No. 276. 2 v 



