316 Transactions. — Geology. 



Art. XLII. — Notes on the Physiography and Geology of the King 



Country. 



By Laurence Cussen. 



[Read before the Auckland Institute, \±th November, 1887.] 



Plate XIX. 



The district to which these notes refer comprises an area of 

 4,000 square miles, extending southwards from Alexandra and 

 Kihikihi for nearly 100 miles : bounded by the Waikato River 

 and Lake Taupo on the east, and on the west by the sea, from 

 Kawhia Harbour to the Mokau River. The triangulation of the 

 district was entrusted to me, and I have been for three years 

 engaged in it. This description professes to be simply one of the 

 topography of the country, with such notes on its geology as 

 time and circumstances would allow me to make : it is given in 

 the hope that it may serve to assist the geologist visiting the dis- 

 trict in the future, and in the meantime throw some more light 

 on the geology of a country of which very little is known beyond 

 the general descriptions of Dr. von Hochstetter, which, how- 

 ever excellent in themselves, include only a small portion of the 

 area under consideration. 



The River Basins. 



The three chief river basins by which this country is drained 

 are those of the Whanganui basin, with a drainage area of 960 

 square miles ; the Mokau, 830 square miles ; and the Waipa, 

 820 square miles. Then there are the rivers and streams which 

 flow into the Waikato River from the west, draining 360 square 

 miles ; those which empty into Kawhia Harbour and the sea on 

 the West Coast, including Marokopa and Awakino Rivers, drain- 

 ing 720 square miles ; and the western side of Taupo Lake, 

 which has a drainage area of 310 square miles. 



Surface Configuration. 



An idea of the surface configuration may be gleaned from the 

 general sections which accompany this paper. It may be said 

 to be that of a broken, hilly country, with a main range traver- 

 sing it from south to north. This range is not, however, a 

 continuous unbroken chain : it begins 10 miles to the westward 

 of the Tongariro group; sweeps round 15 miles to the west of 

 Taupo Lake, under the name of the Hauhungaroa Mountain, its 

 height varying from 3,000 feet to 3,780 feet above the sea-level. 

 The Whanganui River takes its rise in the Tongariro Mountain, 

 and flowing westerly cuts through the range immediately to the 

 south of Maungaku, where it traverses a formation of clay marls, 



