326 PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. [June 9, 



reason why the largest nugget lately found weighs only 2 oz. 17 dwts., 

 if we suppose that the gold discoverable without washing or other 

 modern appliances had been picked up by the prehistoric people. 



DiscrrssiON. 



Prof. Eamsay regarded it as certain that no quantity of gold 

 would ever be found in purely glacial deposits, as in such detritus 

 specific gravity went for nothing ; but when those deposits came to 

 be sorted by water, the gold became apparent, as in this case. He 

 agreed with the author in regarding the granites in Kil-Donnan burn 

 as metamorphic rather than intrusive, and had long held this opinion. 

 The felspathic dykes were probably due to other causes. 



Mr. D. PoRBES, on the contrary, regarded the granite as eruptive, 

 and accounted for the granitic veins following the lines of stratifi.- 

 cation, inasmuch as those were the lines of least resistance. The 

 smaller interstices caused by the intrusion of the granite would be 

 filled with quartz-veins derived from the granite, both probably con- 

 taining gold. He considered that the gold had not been derived 

 from Silurian rocks, but from the intruded granite or from the 

 quartz -veins. 



The Author was inclined to regard the granite in some instances 

 as intrusive, and in others as metamorphic. 



2. OssERVATioiis on the " Ntjggettt Eeee,'' Motint-Tareangower 

 Gold-field. By Dr. George H. P. Uleich, F.G.S. 



The Mount-Tarrangower Gold-field lies about eighty-five miles due 

 'N.W. of Melbourne, at a mean elevation of 1200 feet above the level 

 of the sea. Mount Tarrangower, from which the field derives its 

 name, is a fine, massive, symmetrical hill, 1844 feet above the level 

 of the sea by barometric measurement, thus rising several hundred 

 feet above the level of the surrounding hilly country, and forming 

 a conspicuous landmark for a great distance round. It and its 

 eastern, northern, and southern spurs consist mainly of bluish-grey, 

 hard, metamorphic Lower- Silurian Sandstone ("Hornfels") which 

 crops out in beds, generally thick, but much cleaved, showing a 

 mean strike of N. 12° W., and an easterly dip of 70°-80°. 



About 500 feet dovsru the rather steep western slope of the 

 mount we meet the boundary of the extensive granitic tract, here 

 generally known as ** Bryant's Ranges," but forming part of the 

 large horseshoe-shaped mass of which Mount Alexander, near Cas- 

 tlemaine, forms the highest point at an elevation of about 2800 feet. 

 All along this boundary, which runs nearly due N. and S. for above 

 six miles, numerous ramifications of the granite into the metamorphic 

 rock can be observed, and there are also several small patches (in- 

 liers) of Silurian rock cropping out of the granite, which show in places 

 round their boundaries an evident gradual passage into dark, fine- 

 grained, micaceous, sometimes gneissose granite. It is singular 

 that the strike and bedding of these Silurian inliers appear to be in 

 no way disturbed or to deviate from those the rock shows beyond the 



