652 



DR. J. A. THOMSON ON THE 



[Dec. 1913, 



the amphibolites. Great as are the mineralogical and chemical 

 differences, there can be no doubt that both are derivatives of 

 quartz-dolerites. 



The following analyses (selected from a large series published 

 by Mr. Simpson) illustrate the somewhat variable chemical com- 

 position of the greenstones and the bleached greenstones. An 

 analysis of an albitized quartz-dolerite from Scotland is appended 

 for comparison : — 



Analyses of Quartz-Dolerjte-Greenstones & Bleached Greenstones. 



XXVI. ! XXVII. 



5772 

 1-13 



9-17 

 009 

 1-63 

 5-05 

 3-92 

 0-12 

 1-51 

 0-16 



55-84 

 0-62 



10-38 

 4-39 



12-82 

 0-38 

 0-54 

 4-18 

 3-40 

 0-76 

 1-83 

 0-05 



0-22 



45-55 

 063 



10-88 

 4-14 



13-18 

 tr. 

 2-31 

 7-52' 

 3-04 

 0-26 

 1-74 

 0-27 



46-94 

 0-14 



12-49 

 0-33 

 9-20 

 0-32 

 3-56 

 643 

 1-84 

 2-57 

 0-30 

 0-09 



10-26 I 13-41 

 0-34 I 2-25 



42-01 

 0-81 

 8-42 

 2-45 



15-76 

 0-41 

 1-67 

 7-07 

 2-62 

 1-15 

 0-67 

 0-23 



15'65 



0-30 



59-33 

 3-42 



12-86 

 1-88 

 6-46 

 0-14 

 2-09 

 3-74 

 513 

 2-15 

 2-12* 

 0-48 

 0-388 

 * 



0-044 

 0-215 



Totals 



100-33 



.87 1 99-22 



Bases soluble in aqua regia 



A1 2 3 



Ffe..0 3 



FeO 



IvuiO 



Ma;0 



CaO 



Analyst 



4-46 

 6-49 

 8-42 

 0-09 

 1-63 

 3-34 



C. C. 



Williams. 



3-50 

 4-39 

 11-79 

 033 

 054 

 3-98 



2-90 



C.G. 



Gibson. 



0-78 

 4-14 

 10-50 

 tr. 

 2-08 

 7-28 



2-91 



E, S. 

 Simpson. 



0-31 



0-20 



0-33 



2-45 



8-49 



14-37 



0-32 



0-41 



3-56 



1-67 



6-33 



5-74 



2-94 



3-00 



C.G. 



C.G. 



Gibson. 



Gibson. 



J. D. 



Falconer. 



H 2 0+ andC0 2 



•12. 



XXII. 

 XXIII. 



XXIV. 

 XXV. 



XXVI. 

 XXVII. 



Epidotic greenstone. G.S.M. 1936, Hannan's North G.M.L. 673 E. 



Main shaft, 600 feet. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 67, 

 Greenstone. G.S.M. 1800, western crosscut, 300 feet, Golden Horseshoe 



G.M.L. 993 E. Ibid. 

 Greenstone. G.S.M. 1730, main shaft, Imperial Boulder, G.M.L. 1222 E. 



Ibid. [_' Chlorite-schist.'] 

 Bleached greenstone. G.S.M. 1753, 400-foot level, Ivanhoe G.M.L. 116, 



Boulder. Ibid. ['Lode stuff: chlorite-schist.' ] 

 Bleached greenstone. G.S.M. 1751, western crosscut, 400 feet, Ivanhoe 



G.M.L. 116. Ibid. ['Massive siderite-rock.'] 

 Light-coloured felspathic modification of quartz-diabase. Kettlestoun 



Quarry, Scotland. J. D. Falconer, Trans. Boy. Soc. Edin. vol. xlv, 



pt. 1 (1906) p. 147. 



