8 The Hodgkinson Ooldfield, Northern Queensland. 



large angular or rounded patches. There are also small 

 fragments of white quartz and felspar, with almost a 

 stratified appearance. In fact, the stone at first would be 

 certainly taken for a conglomerate. The black masses I 

 suppose to be hornblende. I have not been able to make 

 any microscopic examination of sections of this rock, which 

 I should think has acquired its present appearance by meta- 

 morphism. It is clearly an intrusive rock, as its appearance 

 amongst the vertical slates and the way it cuts off the reefs 

 show. I remarked that the black crystals are very similar 

 to the peculiar black and pitch-like portions of the trap 

 breccia at Port Douglas, and I think it must belong to the 

 same formation. 



The strike of the slates is about a point E. and W. of 

 N.E. and S.W. This is very nearly the direction of all the 

 ranges hereabouts. The dykes seem to follow the strike of 

 the strata. The ranges are short, and divided by deep 

 passes. There are many in parallel lines, and the sides are 

 scored by many precipitous gullies. The strike of the reefs 

 is nearly north and south, and therefore the edges of the 

 slate strata abut diagonally upon them. The reefs conse- 

 quently do not follow the line of the ranges, but cross them. 

 The slate is very fissile at the outcrops, which are not 

 numerous. At the Tichborne claim it passes into a hard 

 flagstone, and at moderate depths is found to pass into beds 

 of very black, shining talcose slate, and thence into black 

 limestone. There can be but little doubt that in these 

 slates we have a series of folds in which the same strata are 

 often repeated in the anticlinal and synclinal flexures. 

 There is no good natural section to enable one to judge 

 of the exact position of the black limestone. It is found 

 very abundantly, with numerous veins and strings of white 

 calcite, and in the form of marble at the Grattan reef, 

 which is a very rich claim ; and the vein stone of quartz 

 with gold is being worked now in the limestone country. 

 As far as I could learn, no traces of fossils have been found 

 in any of the slates, and, considering the evidence of dis- 

 turbance and metamorphism that is here offered, it is very 

 unlikely that any will be found. There are many geologists 

 who regard limestone strata as of entirely organic origin, 

 and most probably, should any fossils be discovered, they 

 will be in the neighbourhood of these rocks. The black 

 and shining appearance of the stone has induced many 

 to think there were indications of coalj which the black 



