Park. — On the Geology of the Kuaotunu Gold-field. 361 



At Kuaotunu proper the older rocks — of probably Palaeozoic 

 age — consist of an upper series of highly-indurated sandstones 

 andgreywackes, and a lower gold-bearing series of clay-shales, 

 diabase-ash and breccia beds. The former occupy the low 

 spurs and ridges which form the western boundary of the 

 Kuaotunu basin, while the latter descend northwards from the 

 sources of the river, and form the high bush-covered ranges on 

 the east side of the river- valley. 



Classification of Formations. 

 Recent. — Sand-dunes, alluvial flats, and swamps. 

 Lower Tertiary. — Andesite tuffs and breccias. 

 Palceozoic. — {a.) Sandstones, greywackes, &c. 



ih.) Clay-shales, diabase - ash and breccia 

 beds. 



Recent. 



The sand-dunes extend along the coast from Maori Point 

 to the mouth of the Kuaotunu Eiver, a distance of over a 

 mile. They seldom rise to a height exceeding 25ft. On 

 their inland side they are bounded by a wide extent of low- 

 lying flat and swamp land, which follows the course of the 

 river for over a mile and a half. In places the swamp 

 possesses a width of almost half a mile, but in general it is 

 widest at the lower end of the valley, and gradually narrows 

 in the upper part until it ends a little above the Try Fluke 

 battery. 



Lower Tertiary. — Andesite Tuffs. 



When travelling from Coromandel to Kuaotunu this forma- 

 tion is first met with near the summit of the main range, 

 on the slopes looking towards Whangapoua Harbour. From 

 there it extends eastwards to Owera and Matarangi, near 

 Kuaotunu. The tuffs decompose readily into yellow and 

 yellowish-brown clays, but in general physical characters they 

 are undoubtedly closely related to the gold-bearing tuffs at 

 Coromandel and the Thames. Their finely- stratified appear- 

 ance in places would tend to the belief that they were of 

 pyroclastic origin, the materials of which they are composed 

 having probably been derived from submarine or maritime 

 volcanic eruptions of a widespread and violent character. 



The coarse andesitic breccias which are everywhere 

 associated with the finer tuffs consist of large angular and 

 rounded masses of hornblende-andesite, enclosed in a matrix 

 of grey or yellowish coloured ash or tuff-like material. No 

 solid flows of andesite were observed in this district associated 

 with the gold-bearing tuffs and breccias. 



This district affords no evidence as to the age of these 

 gold-bearing rocks. They rest unconformably on a highly- 



