Geology of Warrainiyte Gold field. 517 



Introduction. 



The area dealt with in this paper, as shown on one of the 

 accompanying maps, consists of the whole or parts of the 

 Parishes of Nillumbik, Sutton, Warrandyte, Ringwood, Bulleen 

 and Nunawading, and is on a very rough approximation about 

 130 square miles. The greater portion of this district has 

 been the subject of detailed mapping by the writer. The 

 observations recorded and the conclusions drawn in this paper 

 are based on this work, and therefore it will be understood 

 that although from considerations of space the details cannot 

 be shown on the attached maps, almost the whole of the 

 available evidence has been obtained. 



As some time must elapse before the detailed survey can be 

 completed, and before the fossils collected and to be collected 

 can be determined, the results to date are now brought for- 

 ward. 



It is hoped that the detailed map will be published later, 

 and that suflficient palaeontological evidence may then have 

 been obtained to adequately discuss the stratigraphy of the 

 area. 



The rocks of the district are mainly silurian sediments, and 

 it is with them only that this paper is concerned. Some of 

 the other formations will be considered in a separate paper ; 

 and the physiography is being similarly treated. It is suffi- 

 cient here to state that the silurian rocks form a moderately 

 dissected peneplain a few hundred feet above sea-level. The 

 roughest ground is perhaps at Warrandyte. 



Over a considerable portion of the country south of the 

 Yarra, I have had the great advantage of the excellent topo- 

 graphical map prepared in 1893 by Mr. R. A. Moon. Apart 

 from this map, one has to rely on the parish maps, which, for 

 detailed geological work, are very insufl&cient; and where a 

 series of observations has to be definitely located, rough sur- 

 veys must be made. This was my experience in connection 

 with the Warrandyte goldfield, which is mainly outside the 

 boundaries of Mr. Moon's map. A comparison of the physical 

 features shown on the attached Warrand}'te goldfield map to 

 the north and the south of the Yarra, shows the poverty of in- 



