VOLCANIC ACTIVITY IN SOUTHERN QUEENSLAND. 121 
two areas have several points in common, and although the 
voleanies of the two areas appear to be somewhat different 
in age there is a parallelism in the sequence of their lavas. 
The volcanics of the Drake area have been described in 
considerable detail by Andrews.‘ They ‘‘are referable to 
two distinct periods—an older, consisting mainly of 
rhyolites, and a younger, mainly of andesites.’’ These in 
turn are succeeded by the Drake fossiliferous slates and 
tuffs, but ‘‘the whole, felsites and slates, were shown to 
belong to one great period of sedimentation.’’* Andrews 
further states that the fossils in the covering slates and tuffs 
‘fare of marine types and belong to the Lower Marine 
division of the Permo-Carboniferous period.’’? An early 
Permo-Carboniferous age thus seems to be indicated for the 
voleanics of this area. 
The authors have examined specimens of the earlier 
Rhyolite Phase. These, while generally similar to the 
rhyolites of Silverwood-Lucky Valley, differed from them 
in the possession of veins of colloidal silica and in being 
somewhat mineralised (pyrites being fairly common). As 
neither rock analyses nor petrographical descriptions have 
been published, more detailed comparisons are at present 
unpossible, 
(d) The Berseker Ranges, near Rockhampton.— 
Through the courtesy of Mr. C. C. Morton, of the Queens- 
land Geological Survey, the authors have had an 
opportunity of studying hand specimens regarded by Mr. 
Morton as typical of the great series of volcanics forming 
an important part of the Berseker Ranges. The rocks are 
closely comparable with those typical of the Silverwood- 
Lucky Valley volcanics. Mr. Morton believes them to be 
partly intrusive and partly voleanic, and states that they 
rest upon and intrude the Rockhampton series of Car- 
honiferous age. Further evidence as to age is not forth- 
coming, but this close association of the voleanies with the 
Rockhampton series is suggestive of a Late Paleozoic age. 
(e) The Bowen River Coaifield—On the Bowen River 
Coalfield voleanie agglomerates associated with con- 
7 Andrews, E. C., Min. Res. N.S.W., No. 12, p. 11. 
§ Andrews, E. C., op. cit., p. 9. 
> Andrews, E. C., op. cit., p. 14. 
