Mines and Mineral Statistics. 
73 
perliaps the most easily worked of all the tin deposits ; hut ocenrriner 
as they do, alori" the ereek-beds, the mining operations are very likely 
to be^ impeded by floods, ot wliieh miners have had disco'Qra''’'iii^ 
experience during the past summer montlis. ” ^ 
Gold has liecn found, though not in sulhcient ([uantity to pay, in all 
tlie thi-beai*ing deposits. Sapphires are of common occurrence ; some 
of them are of large size and good colour, and worth up to £15 or ; 
the miners, however, ])ay but little attention to the saving of them. 
As included with the recent accumulations, xiniy also be mentioned 
tbe fnnpient additions of muddy sediment deposited over the river 
flats and other low-lyiiig lands by floods. This may be realized from 
tile effects of the late heavy flood at Juverell, A\'lueh b<*ar testimony as 
to the tliickuess of five sc'dimeiit left on the floors of the houses and 
on the ri\ er flats after hut one inuiidatioii. dho enornious amount of 
earthy matter tlms annually brought down by streams and redeposited 
is very apparent. 
■Whilst these accumulations are taking ])laee, other eflects of 
denudatioiimay be noticed. J refer to those dee]) dykes or gullies 
now furrowing tlie sides of hills and cutting tlirough the alluviEil flats. 
They may he well seen on the river flats m-ar Tnverell ; vherc, twenty 
years ago, tlu! rain-water would spread out and flow away over the 
unbroken surface of the ground, it has since eroded chauiiels, 10 or 
15 feet deep, which had their origin in tlic narrow gullies formed hy 
dray-tracks and cattle-jiads. To what extent these newly-formed 
drainage channels, by the greater facilities they afibrd for tlie rain- 
water to rimofF, may increase tlie liability of the rivers and creeks to 
he flooded in the future, is a subject not unworthy of some considera- 
tion. 
Pleistoceke. 
The pleistocene^ formation includes those drift deposits forming 
alluvial Hats wliich are found mor(‘ or less in all the valleys, ;md 
througli which most of the present streams have worn their channels. 
They consist of gravel, sand, clays, and loam, varying in arninge- 
ment, and their composition depending very much on the nature of 
the rocks from which they have been derived. Thus, iii granite 
country, the detritus is of a coarse sandy eharaeter, witli a little (jimrtz 
drift; thiit from the older tertiary formation consists chielly of waier- 
worn gravel and sandy ferruginous clays ; from the basaltic trap have 
residted thick deposits of black and red loamy ehiy, aflbrding a very 
fertile soil; and those extensive alluvial Hats along the Macintyre 
Piver are formed of tbe detritus from all these rocks, together with 
that hrouglit down by the river fi*om other formations in distant 
localities. In the valley of the Macintyre, as in the river valk'vs in 
other parts of the Colony, several of the.se alluvial deposits occur at 
different heights, forniiug terraces on the sides of the valleys. (Sec 
fig. 2, b.) One patch of this drift, consisting of large water-worn 
boulders and ])ebbles. may bo seen on the south bank of tbe river near 
Inveivll ; it rests on basalt, at about 40 feet above the bed of the river, 
and is now out^ of reach of Hoods. These terrace drifts, therefore, 
mark the suceosive levels of the valley as it became gradually scooped 
out and deepened by the action of the drainage vrater llowing down 
from the high ranges of the Cordillera. 
