Haszaui>. — On Thermal Spriiujs in Lake Waikare. 527 



Akt. LX. — Thermal Springs in Lake Waikare, Waikafo. 



By H. D. M. Haszakd. 



\Read before the Auckland Institute, 3rd November, 1890.] 



Plate XLIV. 



The existence of hot springs arising from the bottom of Lake 

 Waikare has been known to a hmitetl number of people for a 

 considerable time ; but, so far as I am aware, the fact has not 

 been recorded in any way, nor their position marked on any 

 map. 



Whilst surveying recently in the neighbourhood, I there- 

 fore took the opportunity to fix their locality, for future refer- 

 ence, as shown on accompanying plan (PI. XLIV.), and I 

 also append a few notes that may prove of interest. 



The springs are situated about four miles south-east of the 

 Rangiriri railway-station and fifty miles south-south-east of 

 Auckland, being, I believe, the laearest thermal springs, in 

 active existence, to the latter place on its southern side. As 

 shown on the plan, they all rise to the west and south-west of 

 Motukanae (Mullet Island), from the bottom of the lake ; the 

 most powerful one, which I have named Koropupu, being 

 about 3^ chains distant, and innumerable small ones bubble 

 up immediately surrounding the western half of the island. 



Koropupu rises from a muddy bottom through 8ft. of water, 

 and on a calm day bubbles Sin. to 4in. above the surface of the 

 lake. Should the lake be at all rough, however, the position 

 of the spring can easily be found by the strong sulphurous 

 odour that pervades the air near it. At this season of the 

 year (September) the temperature of the water when it reaches 

 the surface is very slightly higher than that surrounding ; but 

 the natives tell me that this is owing to the amount of fiood- 

 water now in the lake, and that in summer, when it has only 

 a thin stratum to force its way through, it is quite hot. 



Motukanae, which is only about 45ft. long by 30ft. broad, 

 is composed of a friable chocolate-coloured sandstone, through 

 and upon which silica and other residuary matter from mineral 

 waters have l)een deposited. The island is in places like a huge 

 honeycomb, from the numberless steam-holes through the 

 ■ rock, though these are all quiescent now. The surface is fairly 

 level, and is about 3ft. above the present water-line of the lake. 

 A little mould has formed on the rock, and a few shrubs and 

 grasses are growing upon it. 



I have made a collection of the different minerals to be 

 found, including the roots of a tree that had been silicified in 

 siti'(, also the casts of some leaves, and forward them herewith 

 for inspection. 



