45 



Wahlenberg, Sowerby, Phillips (Geol. of Torksliire, vol. 2, 

 plate 7, fig. 10) ; and Davidson, Monog. Brit. Carb. Bracheo- 

 poda, in the monographs of the Palseontographical Society, 

 p. 119 t. 28, fig. 2. With it we find the Aviculopecten limce- 

 formis, Morris, described in Strzelecki's work as occurring 

 in the Eastern Marshes, Tasmania. We have also the well- 

 known Devonian forms of Productus cora D'Orb. Spirifera 

 bisulcata, Sowerby, S. vespertilio, unclifera, and Plenrotomaria 

 carinata, Sowerby and Fenestella fossula Lonsdale. These 

 forms are all abundantly represented in Tasmania, especially 

 in the Devonian rocks about Hobart Town, Brighton, &c, &c. 

 Three facts of importance can be gathered from the occurrence 

 of these fossils in the gold bearing rocks of Queensland. 1st. 

 Such deposits are thus associated in point of time with the 

 period of disturbance best represented in Tasmania. Secondly, 

 the strange uniformity which these fossils show, in species 

 extending over wide areas, the lower we descend in geological 

 formations. Last of all, the constant association of gold with 

 Diorite in Australia, especially Eastern Australia, which 

 igneous rock is very extensively found also in Tasmania. It is 

 the deliberate opinion of geologists that the only deposits of 

 gold in paying quantity in East Australia are found in con- 

 nection with, and affected by, the diorites or dioritic veins. I 

 may add that this is my own experience, as drawn from a 

 personal inspection of the following East Australian gold- 

 fields, Sofala, Gulgong, Hill End, Tambaroora, Wattle Flat, 

 Summerhill Creek, Gympie, Monkland, and Peak Downs. I 

 may perhaps venture to ask this further question of Tasmanians 

 — have the dioritic deposits ever yet been fairly tried in this 

 Island? Silurian rocks used to be considered almost sine qua 

 non for gold deposits, and that because the best gold fields 

 occurred where only such rock has appeared, the others, of 

 course as it is now ascertained having been denuded away. It 

 is however, certainly established that the richest gold 

 deposits have been thrown down after the Devonian period, 

 though perhaps much later. 



Secondary formations with characteristic fossils are found 

 scattered through the litoral zone, and that of the table land. 

 Oolitic fossils are found at Gordon Downs, near Peak Downs. 

 At Maryboro Cretaceous beds are represented. The same 

 formations, representing both the Upper and Lower Creta- 

 ceous, are found stretching across the whole western side of 

 the dividing range of North East Australia, forming vast 

 plains, which are the principal feature of Queensland scenery 

 in these quarters. Mr. Daintree is of opinion that the Desert 

 Sandstone (upper tertiary) once extended over all this country, 

 because of its existence in outliers, or in situ on the main 



