202 PROCEEDINGS OP SECTION C. 



the identification of the beds with those of the Bowen River,. 

 probably mainly of the Middle Marine Series. 



A little further south the Upper or Freshwater Series comes in 

 in great force on Walker's Creek and other heads of the Isaacs. 

 These beds are undisturbed and unaltered in this region, and the 

 coal seams are in perfect order. The fossil flora is in good 

 preservation — the silicified trees, which are a notable feature of 

 the Bowen River Upper Series, here bestrew the surface of the 

 ground, having weathered out of the sandstones so plentifully, as 

 to suggest the idea that forests had been felled by human hands 

 and subsequently petrified. An enormous but little known coal- 

 field extends from here southward to the head of the Dawson. 



In Cement Hill, Peak Downs, are conglomerates and shales, 

 the conglomerates containing payable waterworn gold and the 

 shales Glossopteris fronds. This is the oldest known auriferous 

 drift in Queensland, and it must have derived its gold from the 

 waste of a land existing in Carbonifero-Permian times. 



The strata of Gympie Goldfield, consisting of grey shales, black 

 pyritous shales, greywackes, sandstones, grits, and conglomerates, 

 are identifiable by their fossil contents with the Bowen River 

 beds — probably with the Middle or Marine Series. Their relations 

 in the Gympie district to older or newer strata, have not yet, so far 

 as I am aware, been determined. They ai-e only slightly dis- 

 turbed. Sedimentary rocks which have undergone no alteration 

 alternate with others which have become indurated and semi- 

 crystalline. This local metamorphism is probably due to the 

 intrusion of masses of diorite. The richest deposits of gold occur 

 in the reefs where these intersect the black pyritous shales or 

 " slates," and it is impossible to resist the conclusions that the 

 conditions requisite for the segregation and concentration of the 

 gold in the reefs were furnished by the influence of igneous 

 rocks, or slightly auriferous pyrites in the carbonaceous shales. 



By the labours of Mr. James Smith a large area of auriferous 

 rock in the Rockhampton district, including those surrounding 

 Mount Morgan, have been shown to be identical with the Gympie, 

 or Bowen River formation. To this keen observer and 

 indefatigable collector, belongs the credit of having furnished the 

 material for substantiating the claim of the Carbonifero-Permian 

 to much that was regarded as Silurian, chiefly on the ground of 

 " lithological " resemblance. 



The Burrum Coalfield is plainly on a higher horizon than the 

 Bowen River field. It contains a fossil flora in which many 

 plants are common to the Mesozoic Ipswich formation and also, it 

 is said, Glossopteris with a very meagre fauna, most of it peculiar 

 to the coalfield. Had it contained Glossopteris alone, or the 

 Ipswich flora alone, it would no doubt have been classed without 

 hesitation as equivalent either to the Bowen River, or Ipswich 

 Series. Probably to call it Triassic would not be far from 

 the mark, in at least a homotaxial sense. 



