Akt. XI. — Xotes on Certain MetaTnorphic and Plutonic 



Rocks at Omeo. 



By a. W. Howitt, F.G.S. 



In writing on the subject of the Metamorphic Rocks at 

 Ensay * I said that the conclusions to which their study had 

 led me were also those to which I had been brought by the 

 examination of similar phenomena in the Omeo district, 

 where the relations of the sedimentary, metamorphic, and 

 plutonic rocks may be observed and studied on a much wider 

 scale. In the present paper, I desire to bring under notice 

 certain observations which I have made on the relations of 

 the metamorphic and plutonic rocks in one part of the 

 valley of the Livingstone Creek. 



These notes refer only to a part of the Omeo district, that 

 is to say, to a strip of country extending from the Tongeo 

 Gap in the Great Dividing Range to near the junction of the 

 Livingstone Creek, with the Mitta Mitta River at Hinno- 

 munjie. 



The road from Ensay and from the valley of the Tambo 

 River ascends the Great Dividing Range from Tongeo, by 

 way of the Tongeo Gap, at an elevation of 2800 feet above 

 sea level, and thence follows the slopes of the eastern side 

 of the Livingstone Valley to the township of Omeo, at about 

 500 feet below the elevation of the Gap. 



To the right-hand of the Tongeo Gap, in going to Omeo, 

 are the Bo wen Mountains, rising to some 1500 feet or more 

 above it. These mountains are almost wholly composed of 

 highly inclined and more or less altered sediments, which 

 have, in places, still retained the familiar facies of the older 

 pala30zoic or goldfields series of this district. The wide 

 sloping valley falling from them towards Livingstone Creek 

 is composed of varieties of regional metamorphic schists 

 together with masses of intrusive granites and quartz diorites, 

 the former being the most prevalent. 



From near the Tongeo Gap, and running in a direction 

 which approximates to N. 30° W., that is to say, to the mean 

 strike of the lower Silurian formations, there is a more or less 

 well-marked contact of the plutonic and altered sedimentary 



* •' The Sedimentary, Metamorphic, and Igneous Eocks of Ensay." 

 Traneactions Eoyal Society of Victoria, vol. xxii, p. 64. 



