ABSTRACT OF PROCEEDINGS. Xlli 



Abstract of Proceedings, 81st August, 1922. 

 The Ordinary Monthly Meeting of the Royal Society 

 of Queensland was held in the Geology Lecture Theatre of 

 the University at 8 p.m. on Thursday, 31st August, 1922. 



The President, Professor PI. J. Priestley, M.A., in the 

 chair. 



The minutes of tlie previous monthly meeting were 

 read and confirmed. 



IMr. P. A. L. Dunne, who was a member of the party 

 which established the cyclone-warning station on Willis 

 Island, exhibited a large number of specimens, including 

 shells and corals collected during his visit, and gave a 

 general account of conditions on the island. Professor 

 Richards commented on Mr. Dunne's exhibit. 



Professor H. C. Richards, D.Sc, read a paper entitled 

 " Anorthoclase Basalt from Mapleton, Blackall Range, 

 South-eastern Queensland. ' ' The rock described is the first 

 basic alkaline lava containing anorthoclase described from 

 Queensland. It occurs near the head of the Mapleton Falls, 

 2 miles south-west of Mapleton. The flow ha.s abundant 

 lozenge-shaped phenocrj^sts of anorthoclase, and rests on top 

 of an olivine basalt. It is Upper Cainozoic in age, and is the 

 concluding effusion of the must recent volcanic activity. 

 Chemically it differs from the normal basalts forming the 

 Blackall Range in having lower alumina, more iron oxides, 

 less magnesia, considerably less lime, more soda, and twice 

 as much potash. It has chemical characters similar to those 

 of an oligoclase basalt from fSpieer's Peak, Main Range, 

 and of a basalt from IVIount Lindsay, Macpherson Range. 

 The Spicer's Peak basalt is the concluding effusion of the 

 LTpper Cainozoic activity, and the Blount Lindsay basalt 

 of the Lower Cainozoic activity. The similarity of these 

 concluding flows and their departure from the normal seem 

 to be more than a coincidence. Dr. E. 0. I\Iarks and Mr. 

 J. II. Reid discussed the paper. 



Mr. J. II. Reid read a paper entitled "A Note on the 

 Walloon Jurassic Flora." The author concludes: — (1) 

 That ThinnfcJdia, the predominant genus of the Ipswich 

 beds, appears to be practically, if not absolutely, absent 

 from the Walloun in the ^loreton and Roma Districts; (2) 

 that the large-leaved Tteniopteridce, as well as T. Tenison- 

 Woodsi and T. Dunstani, similarly <3o not ascend into the 



R.S.- Q. 



