FiNLAYSON. — Geology of Quartz Veins of Olago Goldfields. 



71 



3. Young Australia Group. — This comprises a number of flat-dipping 

 veins lying for the most part to the south of the last group, and crossing 

 the country rock both in strike and dip. They occur only on the higher 

 slopes of the range, having evidently been denuded off the lower parts. 

 The Border Chief, Heart of Midlothian, and Vale of Avoca veins, lying on 

 the high spur west of the Caledonian group, are also members of this group, 

 the ridge not having been sufficiently denuded to remove them. 



4. Antimony Group. — The veins of this group are similar in character 

 to the others, but they carry bunches of stibnite besides being auriferous. 

 They occur in a scattered group on the summit of the range, to the west 

 of and distinct from tlie other groups. 



CARRICK VEINS. 



Scale : 50 chains to an inch 



A M. Fxnlaysun 



Gold veins . 

 Antimony veins : 



The Fissure-system. — The somewhat complicated system seems to be 

 best interpreted as follows : There have been two sets of radiating fissures 

 formed — the Caledonian and the Carricktown. Their formation was doubt- 

 less due to torsional stress, and the features of these groups are very well 

 reproduced by Daubree's experiments on the fracturing of glass by torsional 

 effects.* There has also been a shearing movement, which resulted in the 

 formation of the flat-lying fissures of the Young Australia group. To this 

 movement are probably due many of the disturbances in the other veins, 

 such as the peculiar horizontal displacements which have affected some of 

 the veins. 



* Daubree, " Geologie Experimentale," 1879, p. 306. 



