55 



NOTES ON THE OCCURRENCE OF GOLD AT PORT 

 CYGNET. 



By T. Stephens, M.A. 



A visit recently paid to Port Cygnet has resulted in a dis- 

 covery which is not without interest from a scientific point of 

 view, if nothing more. Having had to traverse the Huoa 

 district in all directions for several years past, in the discharge 

 of official duties, I had become tolerably famihar with its 

 principal geological features, which present few variations 

 from those that prevail in the neighbourhood of Hobart Town, 

 and the greater part of the Derwent basin. If a line be drawn 

 from the East Coast through Campbell Town to the Great 

 Lake, and thence southwards to Recherche Bay in a direction 

 nearly corresponding with the course of the 147th meridian, 

 the area included between this and the coastline is the only 

 large section of Tasmania in which there is no ground for 

 expecting discoveries of gold or other valuable metals. The 

 sedimentary rocks of the whole of this area may be described 

 in general terms as Upper Palaeozoic. They comprise the 

 carboniferous series, and probably pass upwards into the 

 counterparts of rocks now established in Victoria as Mesozoic, 

 and they are here and there overlaid by Tertiary and Post- 

 tertiary deposits. The whole series, to the Tertiary inclusive, 

 has been penetrated and intersected to an extraordinary extent 

 by trappean and basaltic rocks, which frequently hide the 

 sedimentary strata altogether from view over extensive tracts 

 of country. 



But none of the older rocks, the recognised source of gold 

 wherever it has been found in paying quantities, have hitherto 

 been known to exist within this area, and as the greater part 

 of it has been pretty well explored by the geologist, it is only 

 in an odd corner, here and there, that their presence comes 

 within the range of possibility. The oft repeated announce- 

 ment of the discovery oj gold in small quantities at Port 

 Cygnet, added to a previous acquaintance with the indications 

 of extensive denudation of the upper Palaeozoic sandstones 

 and mudstones in that neighbourhood, suggested to me the 

 idea of paying closer attention to the spots where any of the 

 primary rocks, which by any chance had been elevated above 

 the sea level, might be expected to show themselves. And 

 after a brief examination of the rock exposed in a quarry near 

 the southern extremity of the township, and in a small tributary 



