Chap. XXVI.] lateeitoid cappings. 563 
in all probability rarely greater than 30 to 50 feet, and hence the problem 
Fe-ore Mtirore 
i __• _ 
Lithomar^^e and 
altered quartzite 
< / / < ALTERED 
/ / UOCK. 
Fig. 35. — A lateritoid capping. 
of working them is a simple one. It consists in removing the whole ca p 
of the hill wherever it shows a sufficient proportion of manganese-ore. 
The waste can be thrown down the slopes in any direction, once the 
loose deposits of detrital ore, derived by denudation from the cap and 
lying on the slopes, have been worked over. When the underlying 
soft rocks have been reached, it is hopeless to expect any continuation of 
the deposit at greater depths, except perhaps for a few isolated pockets 
scattered through the soft Uthomarges (or decomposed quartzites), the 
form usually taken by the decomposed rock immediately underlying the 
manganese-ore of the cap. The point then to be settled by the 
operator is whether it is worth his while to turn over this soft 
lithomarge in search of isolated pockets, or whether it is better to leave 
such pockets in the ground. To do the latter would not be a matter 
of much concern to the Government ; for the quantity of ore so lost 
would be smaU ; but it is probable that at times of high prices it 
might pay to work over these soft hthomarges in cases where the 
indications look favourable. 
The last type of deposit to be considered is that illustrated in figure 36, 
namely the deposits of detrital ore, to which I 
have usually referred in this Memoir as detrital 
ore or talus-ore but which is usually termed 
boulder-ore or float-ore by the mining community. These detrital deposits 
are formed by the denudation of deposits in situ and are usually to be 
found on the slopes and at the foot of hills showing an outcrop of 
manganese-ore, being as a rule best ou the scarp side. In the case, alao, 
Deposits of detrital ore 
or talus- ore. 
