Serpentme Area and Mhi/olUes. 263 



100.11 

 Density - 2.827 

 Close to Gan-ey's Hut, on the opposite side of the Dolodrook, 

 fine-grained fragniental rocks, composed of igneous minerals, occur, 

 They are stratified, but weather into long slender boulders, show- 

 ing a marked spheroidal weathering. Here again microscopic 

 evidence show^s that they are composed of fragments of pyroxene 

 and s.erpentine, but it is not clear whether they are sub-aqueous 

 tuffs or normal sediments. These beds overlie the trilobite lime- 

 stone a short distance down the strean), and are so closely asso- 

 ciated with graptolite slates that it appears impossible to sepa- 

 rate them. 



(3) TiiE Limestones. 



These rocks occur as a number of small lenticular outcrops 

 along a line conforming in general to the strike of the ordovician 

 rocks, and a short distance away from the serpentine belt, on its 

 south-western side. The most southerly outcrop is south of the 

 chromite ocoiirrenoe, close to Roan-Horse Gully. Here, as is the 

 general case in this district, the rock is a hai'd bluish-gtey crystal- 

 line limestone. A brachiopod identified by Mr. Chapman as 

 Platystrojjhia biforatn, is abundant in this outcrop, and as this 

 fossil is known to Mr. Chapman in other Victorian limestones, 

 which he regards as Yeringian (Silurian), he considered this 

 limestone to belong also to this series. 



Since this decision, however, trilobites have been found at the 

 other end of the limestone belt, and these fossils open up very 



