SALIENT POINTS IN THE GEOLOGY OP QUEENSLAND. 201 



been observed in New South Wales, from the Lepidodendron beds 

 referred to, upwards into tlie marine beds of tlie Hunter 

 district, nor has any been observed in Queensland from the 

 (Carboniferous) Star beds upward into the (Carbonifero-Permian) 

 Bowen River beds, which represent in Queensland the Newcastle 

 Coalfield of New South AVales. 



The Bowen River formation lies unconformably on granite 

 porphyry, diallage-rock, actinolite-gneiss, mica and hornblende 

 schists, greywackes and shales, probably on the horizon of the 

 supposed Upper Silurian rocks of Mount Wyatt. The formation 

 begins with a thick bed of volcanic agglomerate, which is 

 succeeded by eight hundred and eighty feet of white and yellow 

 sandstones (called the Lower Series of the coalfield). Above these 

 is a series of bedded porphoritic and basaltic rocks. This is over- 

 laid by the Middle or Marine Series, eighteeen hundred and 

 forty-eight feet in thickness, consisting of grey and yellow 

 sandstones, with bands of reddish-ferruginous, and probably once 

 calcareous sandstones, vaiying to impure ironstones, with three 

 or four coal seams. The Middle Series is abundantly fossiliferous. 

 Its fauna is almost entirely marine. Such of the forms as are not 

 new are Carboniferous or Permian. The fern Glossopteris, whose 

 age was at one time a vexed question, occurs along with the 

 Frotoretepora ampla, Lonsd., and Brachiopoda of undoubted 

 Carboniferous types. The Upper Series (equivalent to the New- 

 castle beds of New South Wales) consists of at least nine hundred 

 feet of greyish-green sandstones and red shales, with an abundant 

 flora, of which Glossopteris Browniana is the leading feature. As 

 if to show, however, that the fauna of the Middle Series still lived 

 on in adjacent areas, a bed of marine fossils is intercalated among 

 the plant-bearing beds ; and in this, every one of the mollusca 

 noted has also been recognised as occurring in the Middle Series, 

 and moreover, fronds of Glossopteris have been deposited with 

 them, and must have floated or been blown from an adjacent land 

 surface. There is every indication of a complete sequence from 

 the base of the lower to the top of the upper division of the 

 Bowen River beds. 



A period of volcanic activity followed the deposition, and possibly 

 the upheaval and slight disturbance of the Carbonifero-Permian 

 strata, and basaltic masses were intruded along the planes of 

 bedding, locally destroying some of the coal seams, but producing 

 no marked degree of metamorphism among the other strata 

 beyond contact induration. 



A little to the south of the Bowen River, the Bowen River 

 formation is traceable into the grey and black shales and sand- 

 stones of the Mount Britton Goldlield, where they are not only 

 highly disturbed but somewhat altered, and pierced by impressive 

 dioritic rocks. The metamorphism has not, however, gone far 

 enough to destroy an abundant fauna, suflicient to render easy 



