36*4 Geology of 



Another class of goldfields owes its existence to the destruction of the 

 old alluvial beds, when the gold disseminated through them has become 

 concentrated in the present water-courses or on those narrow terrace* 

 fringing them, which were formed when the river stood at a higher leveL 

 The broader and more numerous the terraces, the less are the chances- 

 of the existence of rich leads. In illustration I have copied from my 

 note-boohs a few sections from theTTaimea district on plate 5. JS"o. 5 

 gives a section near TTaimea township, where the high banks on both 

 sides consist of somewhat micaceous claymarls belonging to the Kanieri 

 formation, topped by alluvium. The river flows here in two branches 

 with a large island in the centre formed of newer alluvium. The 

 working of this bed, although only two feet thick, has proved very 

 remunerative. Ascending the Waimea Creek we find that its channel 

 gradually narrows, and that a mile above the township it runs in a deep 

 gorge cut into the Kanieri beds (Section No. 6.) The alluvial beds 

 along the river are here about 15 feet wide, reaching only a few feet 

 above the present level of the water ; they have proved to be exceed- 

 ingly rich in gold, whilst the terraces on both sides, about 20 feet above 

 the water, have been remunerative only when several favourable con- 

 ditions united. The third section (Xo. 7) is from the lower course of 

 the Kopitea, a small water-course reaching the sea north of the "Waiinea. 

 The old river bed is here very wide, the tertiary cliffs standing a 

 oonsiderable distance from each other, and the low terraces between 

 them being of considerable breadth. This valley was thoroughly 

 prospected in 1S65, but no payable ground could be detected, although 

 everywhere very fine scaly gold in minute quantities was to be obtained. 

 Some of its small tributaries proved, however, of considerable richness. 

 In some instances this auriferous drift occurs either amongst the 

 morainic accumulations, as, for instance, on the Kanieri river, 

 about six miles above the township of that name, or the lower 

 beds containing the precious metal have been preserved by them 

 from destruction. This is well shown in the cliffs at the 

 junction of the Kanieri with the Hokitika river, where old pre- 

 glacier alluvium is immediately covered by silt, over which again 

 an ancient moraine has been accumulating. This alluvium, without 

 doubt brought down in the bed of a large torrent issuing from a 

 glacier then not far distant, often contains a considerable quantity of 

 gold, generally scaly and waterworn. On the Kanieri flat these alluvial 

 deposits have also yielded a considerable quantity of gold. After 

 sinking 30 to 35 feet, where the boulders, having always their edges- 

 somewhat rounded, became of large size, a bed of rather incoherent 



