Geology of the Lower Mitchell River. 17 



fossiliferous ironstones on the river banks below the hotel, the State 

 School, and Saunders' house at Lindenow itself. The ironstone 

 and siliceous sediments shortly disappear, and the banks become 

 less steep and slope gradually up to the higher ground. About 

 half a mile from the ironstone outcrops, limestone shews at the 

 foot of the bank and may be traced down to Bairnsdale, rising 

 in places to a height of 100 feet from base to summit. 



At Rose Hill, about 3 miles west of Bairnsdale, the limestone 

 is immediately overlain by a deposit of a different character. 

 The bank thei'e is strewn with shells like those at Jemmy's Point, 

 and thus of miocene age. A full description of this interestino- 

 bed will be given in the sequel. 



On the upper surface of the terraced banks bounding the flats 

 there is usually a heavy gravel wash, cemented in many places 

 with ferruginous material and in some cases coated with 

 manganese oxide. Similar gravel washes occur in the bed of the 

 river, in places on the surface of the flats, and almost invariably 

 below them. They exist also as low ridges on the tableland fully 

 250 feet above the present bed of the river and with included 

 blocks weighing as much as 60 or 70 lbs. These ridges, no doubt, 

 indicate in general the course of the old streams. They are 

 capped with conglomerate and have worn less than the surround- 

 ing softer country. Gravel containing boulders from six to nine 

 inches in diameter is in fact met witli at least 20 miles from its 

 source, and over 200 feet above sea level. These drift deposits, 

 which have been extensively used for road making and railway 

 ballasting purposes, are slightly auriferous. Indeed, the gravel 

 washes in some parts of the Mitchell River itself, though many 

 miles from any silurian rock, give payable returns. 



The watershed on the north side of the river, so far as tertiary 

 deposits are concerned, includes the country drained by portions 

 of Flaggy Creek, Prospect or Boggy Creek, and Clifton Creek, as 

 well as a few minor gullies. Near Flaggy Creek, where devonian 

 sandstones are exposed, the country rises somewhat suddenly to 

 the north, and thence on to Boggy Creek the river runs almost 

 parallel to the devonian hills, and at no great distance from them. 

 The highest eminence is Mount Taylor where devonian strata, 

 about -iOO feet in thickness, and composed of sandstones, con- 

 glomerates, and shales, rest on porphyritic rock, the upper surface 



