GEOLOGY OF THE KEMPSEY DISTRICT, 159 



of a colourless mineral with low refractive index and weak 

 double refraction. This is probably another felspar inter- 

 grown with that of the large crystal, but the material was 

 insufficient for precise determination. 



Quite scarce are pseudomorphs of brown serpentine after 

 olivine. The shape and internal structure of the original 

 are preserved. 



The secondary material is strongly pleochroic, and its 

 double refraction is quite strong for serpentine. 



There is much apatite in tiny needles. Small spaces, 

 up to 1 mm. in diameter, mostly quite irregular in shape 

 are filled with zeolites, some with analcite, some with 

 stilbite. 



PRELIMINARY NOTE on the GEOLOGY of the 

 KEMPSEY DISTRICT. 



By W. G. Woolnough, d.sc, f.g.s., Lecturer in Applied 

 Geology and Mineralogy, University of Sydney. 



[With Plate V.] 



[Read before the Royal Society of N. S. Wales, August 2, 1911."] 



The author hopes to have an opportunity, in the very near 

 future, of spending sufficient time in the field on the Macleay 

 and Manning Rivers to enable him to lay before the Royal 

 Society a fairly complete account of their geological history. 

 The results obtained during a brief visit in January and 

 February of this year seem, however, of sufficient interest 

 and importance to justify an immediate statement, which 

 may serve as a guide to other observers should it be 

 impossible for the author to carry out his intended inves- 

 tigation. 



