Geology of Castlcmaitie, &c., zvitJi List of Minerals. 81 



the railway cuttings near Chewton, and I could quote many more 

 iu the district. Lithologically, judging by hand specimens, the 

 rock seems to resemble that of the Bendigo dykes which Mr. 

 Howitt calls Limburgite.* At Maldon, in the Eaglehawk Mine, 

 a beautiful green dyke-stone occurs containing massive garnet, 

 hornblende crystals, pyrrhotite and other minerals. Mr. Pritchard 

 tells me that Mr. A. W. Howitt, who examined a specimen for 

 him, says the rock consists entirely of Diallage. 



Mount Consultation, four miles south-west of Castlemaine, is 

 an old volcanic neck. Very little scoriaceous material remains, 

 and on the south side the dense basaltic rock rises almost 

 precipitously fi'om the silurian below. The basalt is almost 

 black, vei-y line grained, rarely vesicular, and has in some places 

 a platy structure. The divisional planes are marked by whitish 

 bands, and have a " dip " of about 40° inwards tow^ards the vent, 

 as shown on an arc of about 90°. The aneroid reading gave the 

 height as 300 feet above the Castlemaine station or about 1200 

 feet above sea level. What is apparently a still more denuded 

 neck, occurs at the head of the southern arm of Diamond Gully. 

 The surface of the rock has been denuded equally with the 

 silui'ian and occupies an ai'ea of about twelve acres, the ground 

 being cultivated. The I'ock is apparently similar to that of 

 Mount Consultation, but contains numerous angular fragments 

 of sandstone embedded in it. A quarry hole twenty-two feet 

 deep occurs, and the owner says the rock grows denser with 

 increase of depth. Lower down the hill a shaft was sunk to 

 pierce the basalt • at twenty -two feet however work was suspended. 

 The gully which heads to this outcrop received its name from 

 the occurrence of zircons, pleonastes and other gems derived 

 probably from the basalt itself. Gems are also recorded from 

 the older drifts of Diamond Hill. In order to ascertain the 

 relative age of the basalt, I tried to find whether any had been 

 procured from the oldest drift on the hill-top, but without success. 



At Guildford, at the junction of Campbell's Creek and the 

 Loddon, we find the older drifts capped by a basalt flow which, 

 originating near the head waters of the ancient stream, has 

 followed its course as far as the junction of Mucklefoi'd Creek. 



Kotes oil Samples of Roclc, &c. Special Hep. Min. Dep., 189c', p. 1. 



G 



