108 The Sedimentary, Metamorphic, 



perhaps to represent one of the deeper-seated masses with 

 which such palseozoic lavas have been connected. 



I may now note further that in the line of this section, 

 and between the Wilkinson and Tambarra Rivers, there is a 

 second considerable exposure of porphyritic rocks, which, I 

 think, will be found to belong to the above group, as I have 

 provisionally noted in the section. 



There remains but little to notice in the final part of the 

 section. The massive intrusive rocks extend, only broken 

 by the porphyritic Diabases which I have referred to, from 

 the summit of the divide west of the Wilkinson to the 

 summit of the mountains on the eastern side of the Tambarra 

 River, where they are capped by tertiary basaltic sheets, 

 and succeeded to the east by well-marked members of the 

 Buchan beds, including both the fragmental, tufaceous and 

 marine limestones of that series. In a former descrip- 

 tion of the Gellingall area I stated that the Buchan beds at 

 that place were laid down on the granitic rocks.* Since 

 then I have seen some reasons to doubt that such is the case, 

 but that the positions of the two formations are perhaps 

 more probably due to faulting. At present I must leave the 

 matter uncertain. 



The description of the samples collected in this final part 

 of the section will conclude the account which I have to 

 give of the rocks met with in its course. 



39. — The granitic rocks are exposed in the bed of the 

 Wilkinson River, where the Gellingall track crosses it. 

 They are traversed by several basic dykes, and by joints, 

 one set dipping S. 30° W. at 45°, and the other to 

 N. 30° E. at 27°. The thin slice which I prepared 

 shows — (a) an iron magnesia-mica, which has been almost 

 wholly converted into chlorite, with exclusion of ores of 

 iron ; (b) felspars of two kinds, of which orthoclase is one, 

 extending over a considerable part of the slice in large 

 masses, and having in parts veinlets of a second felspar ; it 

 also includes mica and a few small well-formed plagioclase 

 crystals, small serpentine pseudomorphs and quartz grains ; 

 (c) Triclinic felspars occur in large imperfectly-shaped 

 crystals, some of which have been broken or have been 

 rounded off; (d) quartz is in moderate amount, as the residual 

 constituent. The most peculiar feature of this rock is the 



* Notes on the Devonian Eocks of North Gippsland, Geological Survey of 

 Victoria Progress Eeport, Part V., p. 117. 



