and tJwir Contact Zones. 17 



PART I. 



1. General Geology of the District. 



In making an extended geological examination of North 

 Gippsland — the oldest formation anywhere met with is 

 a recurrent series of greatly inclined and slightly metamor- 

 phosed slates and sandstone, with quartz veins. These rocks 

 vary from an almost purely argillaceous to an almost purely 

 arenaceous composition. Slaty cleavage is always more or 

 less present. That the strata have been greatly denuded 

 before Upper palceozoic times, is evidenced by their extreme 

 unconformity with these Devonian sediments, which in 

 various localities still rest upon them. In Gippsland, as in 

 various other parts of Victoria, it is found that the older 

 palceozoic sediments, after being tilted, compressed, and more 

 or less metamorphosed, have been extensively intruded into 

 by vast granitic masses, which, on an examination of the 

 contacts, are not found to have generally disturbed the strike 

 of the slates as prevailing in the district, except immediately 

 at the contact, where they have truncated,, crumpled, turned 

 back and broken up the beds. This is more especially the 

 case when the contact crosses the strike of the sediments. 

 In the direction of the dip the strata usually incline both 

 against and from the granite masses; audit is also seen that, 

 especially when the sedimentary rocks have been cut across, 

 granitic apophyses and veins penetrate the strata, and that 

 portions of the latter are occasionally found included in the 

 granite, and either completely cut off from the main mass, or 

 merely attached to it by irregular portions of strata. 



This vast recurrent series of palceozoic sediments, together 

 with the intrusive granitic masses, is in Gippsland found to 

 be older than the Middle Devonian marine limestones, which, 

 as at near Buchan and Bindi, rest upon the denuded surface 

 of both. In other localities, however, younger sediments 

 have evidently been involved in the general folding. These 

 younger sediments are distinguished from the Lower silurian 

 formation, not only by fossiliferous beds fixing their age* as 

 Upper silurian and Middle Devonian, but also by the peculiar 



* The Devonian Rochs of North Gippsland, by A. W. Howitt. Report of 

 Progress of Geological Survey of Victoria, Part III. , p. 183, et infra. 



