GEOLOGICAL SEQUENCE OP THE BOWNING BEDS. 291 



Intermediate group. — Glassy lavas, hornblende andesites, pro- 

 bably belonging to this group have recently been observed by tlie 

 author at Nelson's Bay, Port Stephens. Diorites are of much 

 less frequent occurrence than is popularly supposed. 



Acid igneous. — Volcanic glasses belonging to this group have 

 been met with at Port Stephens, Bulladelah, and near Grafton. 

 Felsite lavas of Eocene age occur at Bailey's Mine and Rose 

 Valley near Emmaville, where they overlie rich stanniferous gravel. 

 The spherulitic felsites of Emmaville were also described, and Pro- 

 fessor Liversidge's account was quoted of the Hartley granite, which 

 was found by him to contain galena, and small crystals of 

 staurolite. 



Pumice occurs at several sheltered spots along the coast line 

 near Sydney, and similar pumice has been observed by Mr. R, 

 Etheridge at Lord Howe Island. Professor Liversidge who has 

 analysed some of this pumice from Bondi, comments on its 

 resemblance to that ejected from Krakatoa in 1883. These 

 fragments of pumice have probably been drifted from some of the 

 volcanic islands of the Pacific, possibly Krakatoa. 



Monday, September 1. 



The following papers were read : — 



1.— THE GEOLOGICAL SEQUENCE OF THE BOWNJNG 



BEDS. 



By John Mitchell, of the Public School, Narellan. 



\^Abriclged.] 



In the present paper I propose to give briefly my conclusions 

 on the Geological Sequence, or Stratigraphy of the Bowning Beds, 

 with some remarks on the Cave Flat or Goodradigbee River Beds. 



As regards the former these conclusions are the result of careful 

 and frequent investigations made during a live years residence in 

 the district. My remarks on the Goodradigbee Beds, are on the 

 other hand, simply based on observations made while on a few 

 short visits to the localities where the outcrops form conspicuous 

 features of the country. For the Bowning Beds I shall retain 

 the same boundaries east and west, as those given in my paper, 

 "Notes on the Geology of Bowning,"* namely, the porphyry 

 near tlie junction of Limestone and Barber's Ci'eeks on the east, 

 and Flinter's Gap (Conroy's Gap) on the west. 



* Proc. Linn. Soc. N.S. Wales, I., 1886. j-"^ 



