172 THE VICTORIAX NATUEALIST. 



volcanic ashes. This conckision is borne out by the fact that 

 recent volcanic formations are nearly always found in close 

 proximity to it. The formation is found in patches throughout 

 all tropical Australia. The geological age of these sandstones is 

 uncertain, but they probably belong to the two great volcanic 

 periods of tertiary age. The lowest beds lie upon the cretaceous 

 formation. 



The following report upon specimens of desert sandstone has 

 been made by Professor Liversidge, at my request : — " I have 

 carefully examined the two specimens — one labelled ' Building 

 stone, Palmerston;' and the other, 'Cliffs, Fanny Bay, Port 

 Darwin.' Both of them are essentially indurated white argilla- 

 ceous rocks, such as are commonly called pipe-clays. They are 

 both only slightly soluble in strong acid, and do not give off 

 carbonic acid, and they both give the reactions for alumina; the 

 Palmerston one is free from magnesia (/.«?., in the acid solution — 

 I have not examined the insoluble portion, except for alumina) ; 

 and the Fanny Bay stone give a trace of magnesia only — hence 

 the name magnesian sandstone is hardly applicable. They seem 

 to correspond to the white indurated clay found in the Hawkes- 

 bury sandstone about the North Shore, &c." 



Minerals. — Arnhem's Land has frequently been represented 

 as a country poor in minerals, or, at any rate, one whose mineral 

 resources were not of a paying kind. It is much to be regretted 

 that the statements of incompetent persons in this matter have 

 prevented speculators from risking their capital. The country is, 

 in fact, fairly rich in minerals ; and if, hitherto, the mines have 

 not paid well, the true cause will be found in the fact that the 

 climate is unsuited for European labour. There is no scarcity of 

 gold, though, doubtless, improved methods of extraction, as well 

 as steady and persevering industry, are required to make it pay. 

 But the important point to be remembered is that Mount IMorgan, 

 one of the richest mines in the world, has been found under 

 geological conditions which are by no means uncommon in the 

 Northern Territory ; and it is not improbable that careful pros- 

 pecting should lead to the discovery of mines not inferior in 

 value. 



Silver is found in many parts of the territory in quartz veins, 

 and also associated with lead and copper. The silver-lead veins 

 have generally been found on the edge of the slates, and near 

 the junction of the granite. Comparatively few of them have 

 l)een prospected as yet, and only one or two have been worked. 

 The Eveleen mine is situated on a small outlier of ancient 

 crystalline limestone. 



The Northern Territory may be said to be exceedingly rich in 

 tin ; in fact, it is decidedly a tin country, the lodes bein,c; more 

 extensive and numerous than in any other part of Australia. Tin, 



