McKay. — On Gold in the Mackenzie Country, Canterbury. 483 



rocks reaching, at liigii levels, to the axil line of the range, but the 

 numerous streams flowing west and south from thence in valleys and 

 mountain gorges of great depth have in many cases removed the higher 

 rocks, and now bring down the waste of the underlying auriferous schists, 

 which, in the case of the Ahuriri Eiver, is carried to its junction with the 

 Waitaki, there being no lake, as in the other cases, to intercept it, or if 

 there ever has been, it has long since been filled up. 



Thus there is a marked difference between the shingle now filling the 

 river beds and that derived from the same geographical position before the 

 higher rocks had been removed ; morainic accumulations, both lateral and 

 terminal, being remarkably deficient in auriferous material, as are the rivers 

 below the outfall of the lakes. 



It will thus be seen that the localities likely to yield gold in any quantity 

 are those rivers and creeks the sources of which cut deep into the auriferous 

 rocks, but this being the case it is often very difficult to find gold even then, 

 as the sources of the rivers are often nothing more than a tremendous 

 aggregation of fallen rocks, many of them exceeding the contents of this 

 room. There is scarcely an intermediate condition between this state of 

 things and an open river bed, in which a hole cannot be sunk more than a 

 few feet without finding that the bottom cannot be reached on account of 

 water. 



Though gold is to be found in many creeks which do not expose the 

 schistose rocks, and from one of these the gold now shown was obtained, 

 as a rule it is otherwise. Its mode of occurrence was very peculiar, and 

 deserves some notice here. It comes from the first creek above Lake 

 Ohou, coming from the west, but gold in quantities more than a mere colour 

 is confined to about a mile of its course only. It is not surprising that 

 it should disappear iu the flat shingle beds near the lake, but its remark- 

 able disappearance above a certain point as the creek is followed up remains 

 to be explained, as there are one or two small flats and terraces which are 

 quite as likely as those in which the gold is found. 



There are two explanations of this. One is that the gold is derived 

 from the destruction of an old lake terrace, cut through by the creek. But 

 as this is not a solitary example of such action, why, I ask, is there no 

 gold at the same relative point in other cases. The other explanation 

 is that the gold is derived from the rocks of the neighbouring range which, 

 a little above the occurrence of the gold, are composed of comparatively 

 loose conglomerates which might be the matrix of the gold. Another 

 solution might present itself, namely, that the gold is derived from a dyke 

 of igneous rock which here crosses the creek, and is exposed over a con- 

 siderable surface of the neighbouring range, but against this is the smooth 



