This item contains the following correspondence:

1. Copy of handwritten letter from Johnson to the Chief Geologist at Aquitane (Australia) Minerals Pty Ltd, discussing formation of phosphate deposits in South Australia and asking if red 'cave earth', crystallised phosphates, or bone and tooth fragments had been found during drilling in phosphate deposits at Clinton, South Australia. 10 July 1978. Two pages.
   
   
2. Typewritten letter from RJ Lee, Area Geologist at Aquitane Australia Minerals Pty Ltd, to Johnson discussing results of drilling at Curramulka, South Australia. 25 July 1978. Two pages.