352 i\'. R. Junner : 



thouglit profitable to break oiu. In the south workings of the Dia- 

 mond Creek mine, the iootwall stone was worlved almost exclusively. 

 North of the shaft, however, both walls have been worked consider- 

 ably. It is taken as a general rule at the mine that if the gold 

 occurs on one wall it will not occur on the other. An exception 

 to this was noted in the 700 feet level north, where the gold occurred 

 on both walls. 



Summapy and Conclusions. 



The study of the Diamond Creek area has brought to light some 

 very interesting relations. The bearing of the present elevation of 

 the river gravels formed before uplift in the direction of the slope 

 of the peneplain has been noted. The stratigraphical relations 

 have been described, and a few fossils found. The discovery of 

 climacographtus and diplograptus in the so-called Silurian near 

 Diamond Creek is of interest, and should act as an incentive to 

 further palaeontological work. The other fossils support a mel- 

 bournian age for these beds. An intimate I'elation between the 

 mining belts and the structural features, especially the anticlines, 

 has been shown to exist. The petrological examination of two 

 dykes from the area brought out some interesting relations; the 

 Diamond Creek dyke appears to be an almost completely altered 

 facies of a rock allied to the Dry Creek dyke. The former dyke has 

 been described as a propylitised quartz felspar porphyry. The con- 

 temporaneous character of the gold and stibnite, and sometimes of 

 the quartz, has been noted. Another interesting feature is the fric- 

 tion breccia and conglomerate, through which the Diamond Creek 

 dyke has been intruded. The relations of the various quartz reefs, 

 the problem of the genesis of the ores, the localisation and cause 

 of the ore shoots, etc., have also been dealt with. Chemical analyses 

 were made of the basalt and of the Diamond Creek dyke. 



In conclusion, the writer Avishes to record his indebtedness to Pro- 

 fessor Skeats for his advice and suggestions on many occasions, and 

 for his kind criticism of the paper; also to Mr. Summers, M.Sc, 

 for help in the laboratory, and references to the literature. He 

 al.so desires to thank Dr. Hall, Prof. Ewart and Mr. F. Chapman, 

 A.L.S., for their kind examination of fossils, and Mr. Grayson for 

 rock sections, and micro-photographs. To Mr. Christian, the 

 manager of the Diamond Creek mine, the writer is greatly indebted 

 for securing him access to the mine, and for information relating 

 to it, and to Mr. Brooks, Mr. Ditchl)>irn, and the various officials 

 of the mine for their kind co-operation in the woik. 



