ABSTRACT OF PROCEEDINGS. XXXI. 



3. By Mr. L. L. Waterhouse : — A specimen of pigottite 

 from Redruth, Cornwall, recently presented to the Uni- 

 versity by Mr. F. Dan vers Power. 



discussion : 



The business was the discussion of Dr. Woolnough's paper 

 on "A Geological Reconnaissance of the Stirling Ranges of 

 West Australia" recently read before the Society. In this 

 paper the theory is put forward that the range is due to 

 an elevation of the softer rocks composing it above the 

 level of the surrounding hard gneissic granites and green- 

 stones. 



This view was supported by Professor David, and con- 

 tributions to the discussion were made by Mr. Somerville 

 and Judge Docker. 



Monthly Meeting, 8th September, 1920. 

 Professor David in the Ohair. 

 Five members and two visitors were present. 



exhibits : 



1. From the Mining Museum: — A collection of fulgurites 

 from Port Macquarie, collected by Mr. T. Dick. 



2. By Professor David : — Volcanic breccia from the Old 

 Man Valley, Hornsby, containing plant stems. 



3. By Mr. W. R. Browne: — Specimens and photographs 

 illustrating arid weathering in the Broken Hill district. 



paper: 

 A short paper on wt The Conditions of formation of Arkose 

 deposits, and their Geological Significance," was given by 

 Mr. W. R. Browne, and was discussed by most of those 

 present. 



