Age of the Alkali Rocks. 



157 



of a mile south of Shag Point on Port Cygnet. N.W. of this is the 

 akeznte or quartz augite syenite outcrop, 1| miles up Forester's 



SKETCH MAP OF PORT CYQUZT AND KETTERINi 



/j/t /■ D . r. S.E.TASMANIA ^ .. o . . 3 



fltkaii Rocks in BJack. Scale of Miles <^ ' ^ ^ 



Rivulet on the back road to Mt. Mary. North of this is the plexus 

 of alkali rocks composing Mt. Mary. East of this on the shores 

 of Port Cygnet are the main outcrops of the much-differentiated 

 alkali-rich rocks of Regatta Point, and various other localities 



