GooDALL. — Geology of Timaru Downs. 455 



finely-crystallized iron pyrites, are likely to be auriferous in 

 parts. Indeed, alluvial gold can be obtained in small quantities 

 almost everywhere along the flank of the range. The beds are 

 here, as at the jetty, quite perpendicular, and even more con- 

 torted and crumpled. As they recede from the range they 

 flatten out to a gradually-decreasing N.E. dip, and change in 

 character to a massive indurated sandstone of a greenish colour, 

 often studded with splendid crystals of iron pyrites that stand 

 exposure for a long time without rusting. 



It is in these blue compact slates that fossils are likehest to 

 be found. I have often seen what I took to be fragments of 

 shells, but have never been able to prove conclusively that such 

 was the case ; but from the abundance of lime in the composition 

 of these blue slates it is almost certain that shells were embedded 

 with them, and may still be found where the conditions of 

 preservation are most favourable. They are not so much 

 metamorphosed as might have been expected from their close 

 proximity to the granite, and in some places fossils are quite 

 likely yet to be found. The Bluff Harbour itself seems to have 

 been at no distant date a freshwater lake. The floor of the 

 harbour is a soft bluish-green very h-iable sandstone, scarcely 

 more than hard-pressed sand with a little clay in it, and highly 

 micaceous. There is not even a spectroscopic trace of lime in 

 it, which must have been the case had it been a marine deposit. 

 There is a good deal of sulphur, as sulphide of iron, which sea- 

 water would have decomposed. There is also timber, quite 

 fresh, and apparently in situ, from the roots being dredged up 

 by the dredging-machine, with the embedding clay still adhering 

 to the curly gnarled roots as naturally as if the tree had been 

 pulled out of the ground on which it grew. The timber 

 dredged up was evidently that of rata {Metrosideros lucida), 

 which is still abundant in the vicinity. 



Art. LX. — On the Formation of Timaru Downs. 



By John Goodall, M. Inst. C.E. 



[Read before the Hawke's Bay Philosophical Institute, 12th July, 1886.] 



Plate XXVIII. 



Dr. von Haast, in his work on the " Geology of Canterbury and 

 Westland," p. 367, ascribes the formation of the Timaru plateau 

 to a sub-aerial origin, and compares its structure to the loess (or 

 loam) deposits of China, the Ehine, and Danube, as described 

 by Baron von Eichthofen, the eminent German traveller and 

 geologist, who, he says, "has shown in his last publications 



