Jievietcs — Geology of Western Australia. 119 



II, — Geological Survey, "Western- Afsxralia. Bulletin Nos. 24, 25, 

 1906; Nos. 26, 30, 1907. A. Gibb Maixlakd, F.G.S., Government 

 Geologist. 8vo ; with maps, plates, and figures in the text. 

 Perth, W. A. 



BULLETIN No. 24 contains an account of the Laverton, Burtville, 

 and Erlistoun auriferous belt of the Mount Margaret Goldfield, by 

 Charles G. Gibson, Assistant Geologist. The report is one of the 

 special series dealing with the mineral resources of the State, and it 

 includes a brief summary of the work of other observers in the 

 same area. 



The boundaries of the Mount Margaret Goldfield embrace an area 

 of 42,252 square miles. The formations met with constitute a complex 

 of crj'stallme rocks, to which the general terms * greenstone ' and 

 'granite' are provisionally applied. The greenstones are essentially 

 hornblende rocks, ranging through typical diorites to a fine-grained 

 rock, consisting almost entirely of hornblende. The granitic rocks are 

 in some places found to be intrusive in the greenstones in the shape of 

 dykes and masses ; in others their relations to the greenstones cannot 

 be determined with certainty owing to the covering of recent deposits. 

 They vary in character from a dark hornblende granite or quartz- 

 diorite, to a light coloured quartz-porphyry. The group of rocks here 

 called greenstones is the most important from the economic point of 

 view, as it generally contains the auriferous ore bodies. 



This report is illustrated with geological and mining maps and 

 illustrations of geological phenomena. 



Bulletin No. 25 is a report upon the " Prospects of obtaining 

 Artesian Water in the Kimberley District," by E.. Logan Jack, who 

 was specially appointed to undertake the work. After referring to 

 previous surveys made by E. T. Hardman, H. P. Woodward, and 

 A. Gibb Maitland, which paved the way for later investigators, the 

 writer takes the geological formations met with in the district as 

 follows : — 



Carboniferous Sandstone. 



Carboniferous (?) Limestone. 



Devonian Sandstone, Grit, and Limestone. 



Metamorphic Pocks — Slates, Schists, Gneisses, etc. (Silurian, 

 Cambro-Silurian, or Cambrian). 



Granite. 



Basalt. 

 These are briefly described from the author's observations while 

 drawing special attention to the j)ioneer work of Hardman in this 

 field. In summing up his results Dr. Jack refers to the nine distinct 

 areas that he examined and in which he anticipates more or less 

 success in the search for artesian water. He concludes that the latter 

 is destined to play an important part in the pastoral industrj' of the 

 Kimberley District. An appendix to this report gives an itinerary 

 and notes on water. There is also a coloured geological map (scale 12 

 miles to 1 inch) with explanatory^ notes upon its face, and a full index. 

 Bulletin No. 26 includes a series of reports which were too short to 

 be separately issued. They relate to the mineral and other resources 



