13 



Geological Horizon Douhtful. — 4. Glacial clays and sand- 

 stones, with erratics. 



Primary. — 5. Metamorphic quartzites, sometimes passing into 

 schistose structure. 



In no part of its course (south of Nettle's Hill) does the Hind- 

 marsh River flow over the Primary rocks, and consequently no 

 opportunity presented itself of finding such examples of polished 

 ice pavements as occur in the Inman. The Valley flats and 

 minor hills are composed of Newer Tertiary beds, as described 

 above. In the lower reaches of the Valley these beds attain a 

 considerable thickness, and effectually obscure the underlying 

 beds. Good sections may be seen in washaways and steep cliffs 

 up to 50 ft. in height, and it is in these Newer Tertiary beds 

 that the river has cut its way and laid down more or less a 

 secondary deposit of recent alluvial wash. 



In some parts of the valley, especially on the higher flats, the 

 surface is a loose white sand, densely occupied by scrub. 



On all sides there were presented the strongest proofs that in 

 post glacial times the valley has been subjected to much silting 

 up, the glacial deposits have been wasted, rearranged, or blinded 

 by an excess of cover, and the wonder is that any evidence of 

 their presence has been left to tell its tale. 



A very large granite boulder was met with on Mr. Alexander 

 Hutchison's land, distant from the river about three-quarters of 

 a mile, on its western banks, and immediately on the line of 

 fence separating Sections 205 and 218, Hundred of Encounter 

 Bay. The stone was originally so large that it formed an 

 obstacle to the fence, and had to be blasted before the wire could 

 be carried through. Two shots had been inserted, reducing the 

 part exposed above ground to half a dozen pieces, the largest of 

 which measures 4 f t. x 3 ft. x 3 ft. The base is still set firmly 

 in the ground, and the part exposed measures seven feet across. 

 It is a red granite with the characteristic features of the Port 

 Victor and Port Elliot granites. 



Two other large granite boulders were pointed out to me by 

 Mr. Hutchison occuring on his land on the eastern side of the 

 river. One of these was situated near the eastern edge of Section 

 117, Hundred of Goolwa, and the other near the middle of the 

 adjacent Section 143, Both boulders are nearly even with the 

 ground, and have an exposure of five feet and four feet respec- 

 tively, but it was apparent that if the soil had been removed 

 their dimensions would have been shown to be much greater. 



Following the road for about two miles, and rounding the 

 prominent spur of the Peeralilla Hill, as the road passes 

 through Section 136, a low cutting on the right hand side of the 

 road exposes a drift bed containing many erratics, including a 



