158 Notes on the Geology of the 



Manganese, chromium, sulphur, and phosphorus were 

 specially looked for, but not found. 



Pure hydrous oxide of iron should contain 59*89 per cent, 

 of metallic iron, and 14*44 per cent, of combined water. 

 From the water in these ores being present in only about 

 one-third the quantity that it should be, it would seem 

 that the ores are a mixture of the anhydrous oxide 

 (red hematite) and the hydrous oxide (limonite). The 

 third lode is at the limestone quarries last mentioned, and 

 has not been worked. There is a doubt about the age of 

 the second lode (at Douglass'), and it is possible that, when 

 properly explored, it may prove to be an ore-bed of carboni- 

 ferous age. These lodes are all more or less at right angles 

 to the prevailing strike of the rocks bounding them. Other 

 smaller outcrops occur, but are not of much importance. 



Mr. Gould's theory that the " iron deposits and outcrops 

 are referable to one line of force, determining lines of fracture, 

 which, in the sandstone and grit formations, have been 

 filled with crystalline brown hematite, and, in the serpentine, 

 with magnetic oxide," will not hold good, as he has evidently 

 suited the position of these deposits and outcrops on his 

 map to his theory. His supposed line of fracture is a north- 

 west one, in the strike of the country, and the true lodes are 

 nearly all east and west, or almost at right angles to the 

 strike ; whilst the ironstone deposits, mentioned further on, 

 are undoubtedly tertiary cappings, which may or may not 

 have connection with lodes below, of which, however, there 

 is no evidence other than the occurrence of masses of magnetic 

 iron in the limonite. 



The only reefs known to be auriferous are those at Brandy 

 Creek — but at the time of my visit the only reef yielding 

 good returns was the celebrated " Tasmania." Other reefs 

 struck payable-looking stone, but had to wait the advent of 

 a long-promised crushing company. 



In the area occupied by serpentine, the highest hills con- 

 sist at their summits of a coarse or fine-grained glittering 

 black rock— a gabbro, composed apparently of a triclinic 

 feldspar and brown mica, ' or perhaps diallage. These 

 points, of which there are six or seven, are scattered uncon- 

 nectedly round Mount Vulcan. The gabbro passes rather 

 abruptly, on the flanks of the hills, into a very uniform, 

 both in texture and colour, deep green, oily-looking, semi- 

 translucent rock, with bluish opaline veins, showing rarely 

 traces of lamination, or seeming bedding planes, which have 



