24 Proceedings of the Royal Society of Victoria. 



mica. It is greatly decomposed, forming a cold, poor soil of 

 little depth, mainly of siliceous fragments with numerous pieces 

 of rose quartz. The Black Creek contains granitic detritus only 

 and from this point a plateau rises gently over a light grey 

 biotite granite, with well-defined bosses here and there, to the 

 " Gehi Wall," where the igneous rocks give place to vertical grey, 

 yellow, brown and olive-green phyllites, argillaceous schists and 

 slates. Many of them are exceedingly fissile, while others break 

 into irregular, ragged-edged pieces. The boundary is plainly 

 marked by a much more vigorous growth of timber on the 

 " Wall " than on the plateau. The rocks have an almost due 

 north and south strike, and so steep is the descent into Bain 

 Creek at the foot that in a distance of some 350 yards the 

 height comes from 2225 feet to 1400 feet. 



Between Bain and Gehi Creeks the track crosses the point of 

 a small spur where the rocks are similar to those in the "Wall." 

 No outcrop occurs on this point, but in the bed of the Gehi 

 Creek at the foot of the spur a striking example of contact 

 metamorphism may be noticed. The original slates having a 

 S. 50° W. dip of 61° have been transmuted into white, black, 

 brown and grey porcellanite, lydianite and jasper, while on the 

 southern bank a mass of grey granite outcrops at the water's 

 edge, showing clearly that the stream at this point flows along 

 the line of junction. The granite extends to the bank of the 

 Gehi River near, and evidently the spur between the river and 

 creek is composed of the same rock. The pebbles in both streams 

 consist of the rock already mentioned as well as mica-schist, 

 slate and quartzite, with glittering sand of white, yellow and 

 black mica. In the river are large boulders of the local granite. 

 At the " Wall " the stream enters a precipitous cailon and from 

 its source to here is known as the Gehi. 



At none of the three river fords close by is there any evidence 

 of sedimentary rocks in situ, yet as the pebbles in the river above 

 the creek junction include many of metamorphosed sedimentary 

 origin it is highly probable that an outcrop of those rocks occurs 

 in the neighbourhood. There is a marked absence of fossils in 

 the " Wall," but judging by the great inclination and lithological 

 characteristics of the rocks they are probably Lower Silurian. 



