59^ J ournai of Agriculture, Victoria. [loOcx., 1912. 



III. 

 NOTE ON LIMESTONE DEPOSITS IN VICTORIA. 



Will C. Robertson, Chief Deputy Chemist. 



An extensive deposit of limestone of a fair degree of purity, say, 90 

 per cent, calcium carbonate, may be a valuable asset in any country, but 

 from the stand-point of agriculture, especially in a State where closer 

 settlement is in its infancy, this asset becomes dead stock if the environ- 

 ments preclude facilities for economical working. 



The lime required by the builder is a different thing to the lime needed 

 by the agriculturist, inasmuch as the former looks for a product with as 

 high a percentage of lime as possible, and is prepared to pay a price for 

 it. On the other hand, whilst the agriculturist would not say no to very 

 pure lime, still, for the purposes for which he requires it, the high price 

 that builders pay might not be justifiable. At present, therefore, the 

 agriculturist is content with a product of a lower degree of purity sup- 

 plied at a much cheaper rate. Consequently a limestone deposit, to be 

 of any practical value to the agricultural community, must possess the 

 following advantages — 



(a) It must be of great extent. 



(b) It must occur near the surface, and be easily quarried, thereby 



removing the difficulty of overburden, and minimizing the 

 cost of labour. 

 ic) Means of railway or seaboard transport must be handy. 

 {d) An abundance of fuel adjacent. 



{e) The percentage of calcium carbonate in the raw material should 

 be at least 80 per cent. This would give on burning a pro- 

 duct containing approx. 69 per cent, caustic lime. 

 These conditions are necessary if the limestone is to be burnt with the 

 object of using "free caustic lime," but if "mild lime," in the form 

 of ground limestone, is to be the object, then the same conditions apply 

 with the single exception of fuel abundancy for which condition there 

 needs to be substituted the pro\ision of the raw material being of a soft 

 tendency to perm it easy grinding. 



The chemist's branch of the Department of Agriculture has paid 

 especial attention for years past to the all important subject of limestone 

 deposits for agricultural purposes, and whenever possible, investigations 

 have been conducted and analyses made, with the object of .solving a verv 

 difficult problem. 



A glance at the Mines Department list, showing the occurrences of 

 limestone deposits in Victoria, elicits the information that 40 per cent, of 

 these deposits are unavailable through the depth of occurrence and trans- 

 port difficulty ; amongst such are those situated at Mitchellvale, Bindi, 

 Limestone Creek, Buchan, Wombat Creek, and Mount Wellington, whilst 

 those at Netherby and Deutgam (Werribee) occur far too deep for economi- 

 cal working. 



The deposits at Curdie's River, Coimadai, Dutson, Lilydale, Waratah 

 and Batesford are being rrined extensively, whilst those at Kawarren, Mans- 

 field and Mitchell River are being worked in a smaller way. 



The remaining deposits at the present moment are not being utilized. 

 It will, therefore, be .seen that, of the twenty limestone occurrences listed, 

 45 per cent, are being worked, 40 per cent, are unavailable, whilst the re- 

 maining 15 per cent, are in abeyance. 



