17 



EEMAEKS ON THE GEOLOGICAL STEUCTUEE OF 

 PAET OF THE NOETH COAST OF TASMANIA, 

 WITH SPECIAL EEFEEENCE TO THE TEETIAEY 

 MAEINE BEDS NEAE TABLE CAPE. 



By T. Stephens, M.A. 



The interesting collection of rocks and fossils recently 

 presented to the Museum by Mr. Hainsworth, of Table Cape, 

 calls for something more than a passing notice, and the 

 occasion suggests a brief considera,tion of the succession of 

 strata exhibited by the coast section from the Tamar to 

 Circular Head. 



Between the Tamar and Port Sorell, the Primary rocks are 

 extensively developed. They consist chiefly of slates, schists, 

 limestones, quartzite, and conglomerates, with a general strike to 

 the N.N.W., and they are to be seen continually recurring 

 with anticlinal and synclinal undulations along the whole line 

 of coast from Badger Head almost to Cape Grim. So little is 

 known of the palaeontology of these rocks, that it is impossible 

 to do more than hazard a conjecture as to their relative 

 position or age ; but they comprise representatives of rocks 

 which show themselves near the Grampians in Western 

 Victoria forming possibly the base of the Lower Silurian series 

 or even of still older date, and they certainly range in an 

 upward direction as high as Upper Silurian. Slight traces of 

 gold have been found at various points, but there is a singular 

 absence of the dykes and veins of true quartz, and other 

 features which characterise the auriferous slates of similar age in 

 other countries. Still, the absence of all trustworthy indica- 

 tions of the presence of gold in paying quantities has not 

 deterred the " practical digger " from wasting his money and 

 time in prospecting such localities as the head of Middle Arm 

 on the Tamar, and even more unpromising spots. Very rich 

 red and brown haematites, with other ores of iron, are met with 

 at various points, and notably on the west bank of the Tamar, 

 where they have been fully investigated and reported on by 

 Mr. Gould. Thin veins of galena associated with sulphurets 

 of copper and iron, and carbonates of copper, occur near the 

 Leven, and though the surface indications in that particular 

 locality are not encouraging, they may some day be found 

 further inland developed in valuable lodes. 



Eesting unconformably on these Primary rocks and usually 

 occupying the ancient valleys formed by their elevation are 

 sandstones and shales containing thin seams of excellent coal. 

 They are associated with calcareous beds containing Spirifera 



