304 Ernest W. Skeats : 



Heathcote lies about 7i miles north of Melbourne, on the 

 Bendigo road, and within the valley of the Mclvor Creek. The 

 field observations in this paper are the outcome of several visits 

 to the district. I have beeoi assisted in my observations by m.y 

 assistants, Mr. H. J. Grayson and Mr. H. S. Summers, M.Sc, and 

 during one visit of four days by the members of the Geological 

 class of the University of Melbourne. The area visited extends 

 from Photograiph Knob, in S. Heathcote, on the south, to a little 

 beyond Lady's Pass, in Dargile, on the north. The junctions 

 of the Ordovician rocks with the cherts and with the igneous 

 rocks in this area, have been carefully examined in the field, 

 oolleotions of the rocks have been made, and about 80 rock 

 sections have been examined. Both in the field and in the 

 laboratory the hypotheses and evidence of previous workers have 

 been examined in conjunction with my own observations. 

 Further work, over a more extended area is necessary 

 before all the obscure questions in Heathcote geology can be 

 resolved. In this communication certain questions raised in 

 previous papers are reviewed, a number of hithertO' unrecorded 

 observations are set out, and their bearing on earlier evidence 

 and hypotheses is considei'ed. I hope at a later date to deal 

 with the evidence from the Northern and the Southern extensions 

 of these rocks, and meanwhile offer this paper as a contribution 

 of facts and of tentative conclusions from them, which it is 

 hoped will be of some service towards the solution of the prob- 

 lems of the district. 



2. — Previous Literature. 



1. Geol, Sketch Map of Victoria, by Sebvyn, 1866. The rocks 

 of the Heathcote district, apart from Lower and U. Silurian, 

 were marked as trap and described (p. 172) as dykes. 



2. Descriptive Catalogue of the Rock Specimens and Minei'als 

 in the National Museum, Melbourne, by Selwyn, 1868. On page 

 l^ the rock from Mt. Camel was described as diabase, but in the 

 list of errata the name was changed to diorite, as the ferro- 

 magnesian mineral was identified as hornblende, and not 

 pyroxene. On p. 18 the substance named " Selwynite,'' then 

 regarded as a mineral, was described as " in a vein in the U. 

 Silurian rocks," indicating Sehvyn's view that the basic rooks 

 were intruded in post Silurian times. 



