lo Dec, 1912.] Notes on t/ie Occurroice of Lniic in Victoria. 771 



crops of similar beds to those at Ka warren, Love's River, and Timboon. 

 Tliese vary in composition from 40 to over 90 per cent., and are largely 

 availed of by the surrounding farmers. The following analyses are 

 from various deposits on the Cobden to Princetown road : — 



CaCO, .. 

 FeA. Al.,0, , 

 MgO . . 

 P.,0, . . 

 S63 



Insoluble 

 Organic matter . 



On the north shore of Lake Corangamite there are deposits of both 

 limestone and gypsum. 



In addition to the polyzoal beds at Portland there are extensive 

 dune rock deposits extending for some distance inland. 



Along the Glenelg River from its mouth to above Dartmoor cliffs 

 of tertiary limestone form the principal feature. Outcrops of similar 

 formation as well as dime limestones are frequent throughout the 

 districts between the Glenelg and the South Australian boundary. 



Boring operations have proved the existence of beds of polyzoal 

 limestone of many hundreds of feet in thickness from Portland to 

 Wilcannia on the Darling River, New South Wales, underlying the 

 whole of the Victorian mallee country and the county of Lowan, and 

 that part of South Australia east of the Murray River, but they are 

 of no industrial value owing to their inaccessibility. 



The most extensive lime deposits in Victoria, however, are on the 

 surface of the mallee country, and occur in three forms. Limestone 

 rubble generally only a few feet in thickness and of concretionary 

 origin, spread over the whole district. It is not very rich, but has 

 been extensively used for building purposes. Analysis (limestone 

 near Mildura) : — 



Percentage. 



CaCO, .. .. '.. 57.45 



Insoluble matter (sand) . . . . 35.91 



Undetermined . . . . . . 6.64 



Fresh-water limestone deposits occur at Rainbow. Cow Plains, 

 Ned's Corner, and at Sunset. These are very rich, but at Cow Plains, 

 at any rate, are rather high in magnesia for agricultural use. They 

 cover many square miles of country, and are 30 feet and over in thick- 

 ness. Analysis (Cow Plains limestone) : — 



Percentage. 



CaCO, .. .. 67.89 



MgCd, . . . . 18.59 



Insoluble (sand) . . 11.22 



The third mode of occurrence is as gypsum, locally termed copi or 

 cow. the aboriginal term for white. As a creamy-white floury powder, 

 apparent^ amorphous, but really minute typical crystals, gypsum 

 occurs as mounds of 20 or 30 feet in height, some few chains in width, 



