Rocks of the Howqiia River. 35 



.therefore tO' be able to treat the new, area in a comparative manner 

 with the better known regions. While there are certain gaps and 

 differences in the Howqua region, as compared with Lancefield. 

 Heathcote and the Dolodrook, near Mount Wellington, many of the 

 comparisons are strikingly similar. It is possible to match many 

 of the special rocks of Heathcote so closely that were the specimens 

 not labelled, it would be impossible to distinguish them from each 

 other. 



The problems of the Heathcotian series and the controversial 

 questions wherein Professor Skeats, Mr. E. J. Dunn, Professor J. 

 W. Gregory, and the late Dr. A. W. Howitt either agreed with or 

 differed from each other, have been ably set out by Professor Skeats 

 (4 and ^), so that it will only be necessary to enumerate here in 

 due place those special aspects which call for consideration in con- 

 junction with the Howqua area. Many important features in the 

 Lower Palaeozoic history and structure in Victoria are dependent 

 on the elucidation and interpretation of the origin, age and rela- 

 tionships of the various rocks in the scattered inliers of diabases 

 and cherts, now generally included in the Heathcotian series. Re- 

 garding this series, field work proves that the Heathcotian conform- 

 ably underlies graptolite bearing Lower Ordovician rocks, and on 

 field evidence therefore it might be Lower Ordovician or Cambrian. 

 It is on the reconsideration of the Dinesus material on which the 

 original claim for a Cambrian age, subsequently abandoned, is 

 now reasserted, and appears to be established, that it becomes 

 necessary to include the lowest beds generally known as Heath- 

 cotian in the Cambrian. 



2. — General Location of the Howqua Region. 



The area under consideration lies to the south-east of Mans- 

 field just within the rough mountainous region of the central 

 highlands of Victoria. It is distant by road from Mansfield about 

 22 miles. For 12 miles, as far as Merrijig, on thci Delatite River, 

 the road is good, thence the route follows an old track little used, 

 and in a very poor state of repair. By this a steep ascent is made 

 over the shoulder of a ridge overlooked by Mount Timl>ertop, to 

 drop down into the deep mountainous valley of the Howqua, a 

 striking contrast in its rugged and almost uninhabited character 

 from the open park-like grazing and farming district of Mansfield. 



4a 



