130 SCIENCE PROGRESS 



Instead of the reefs being scattered haphazard, they are dis- 

 tributed on a beautifully simple and regular plan. Reef after 

 reef has been discovered at lower levels by sinking along 

 " centre country," as the axial plane of the anticlinals is called, 

 until reefs are now being worked at the depth of 4,250 ft. 



The saddle-reef plan has enabled the reefs to be followed 

 northward as well as downward, along the axial lines of the 

 folds ; the saddle reefs have been traced for 6 miles north 

 and south, and the most flourishing mines at present are at 

 Eaglehawk, on a formerly neglected extension of the Bendigo 

 goldfield. 



The discovery of the plan of the field has enabled the miners 

 to follow the reefs with certainty, instead of playing with them 

 a game of blind man's buff; and the system of local manage- 

 ment, under men whose instincts have been trained by long and 

 close study of the ground, enables the mining to be conducted 

 with such economy that, at some of the mines, 2 dwt. ore has been 

 made to yield dividends. South African Mines, the Johannesburg 

 mining paper, recently quoted (September 9, 1905 : vol. iii. 

 p. 624) the results at two of the Bendigo mines with expressions 

 of wonder and envy. 



(b) Castlemaine 



Saddle reefs are also well developed in Victoria, in the 

 goldfield of Castlemaine, of which a valuable account has been 

 published by one of the most rising of the younger Victorian 

 geologists (Mr. W. Baragwanath, jun.). 1 The Castlemaine 

 goldfield presents a striking contrast -to the neighbouring 

 field at Bendigo. At Castlemaine the surface gravels were 

 phenomenally rich, whereas the quartz lodes have been poor. 

 The alluvial deposits were richer than that at Bendigo, and the 

 lodes much poorer. Deep quartz-mining at Castlemaine has, 

 on the whole, been disappointing. 



So far as I know, no adequate reason for this anomaly has 

 been offered. The explanation seems to be that at Castlemaine 

 the gold-mines are close to the intrusive granitic rocks of the 

 Harcourt Range. There was, therefore, much greater secondary 

 concentration in rocks, which have been removed by denudation, 



1 W. Baragwanath, jun., "The Castlemaine Goldfield," Mem. Geo/. Surv. 

 Victoria, No. 2, 1903, 36 pp., 13 plates and 19 plans and maps. 



