OCCURRENCE OF GOLD. 



57 



AUSTRALASIA. 



Victoria. In quartz reefs, mostly through lower Silurian 

 rocks, and a lesser number through Upper Silurian. The 

 direction of the majority of the first set is W. of N., that of 

 the remainder E. of N. Not only have the ordinary allu- 

 vial deposits, as generally found near the surface in drifts 

 washed down from the gold-bearing lodes in the higher 

 land, being extremely rich, but also (as in some parts of 

 California) the beds of ancient streams which have been 

 covered by other aqueous deposits over which lava once 

 flowed. The following diagram will exemplify the position 

 of such a rich " gutter " : 



MNW 



SSE, 



FIG. 38. SECTION OF THE OLDER DSIFTAL GOLD DEPOSITS XEAB BALLARAT. 



Scale : Hor. 1" = 10 chains ; Vert. 1" = 320 feet. 



o, Drift. I, Basalt, c, Black and red clays, d, Basalt, e, Light coloured clays. 

 /, Basalt. 1, 1, 1, Auriferous drift. 



The saddle reefs of Bendigo lie between such strata as 

 sandstone and sandstone, or sandstone and slate ; and are 

 met with chiefly at anticlinals, tapering out in depth. 



FIG. 33A, EXAMPLE OF SADDLE RTSEF FORMATION. 



