1836.) GREAT VALLEYS. 439 
a gorge 2200 yards in width, and about 1000 feet in depth. 
Other similar cases might have been added. 
The first impression, on seeing. the correspondence of the hori- 
zontal strata on each side of these valleys and great amphithea- 
trical depressions, is that they have been hollowed out, like other 
valleys, by the action of water ; but when one reflects on the enor- 
mous amount of stone, which on this view must have been re- 
moved through mere gorges or chasms, one is led to ask whether 
these spaces may not have subsided. But considering the form 
of the irregularly branching valleys, and of the narrow promon- 
tories projecting into them from the platforms, we are compelled 
to abandon this notion. ‘To attribute these hollows to the pre- 
sent alluvial action would be preposterous; nor does the drain- 
age from the summit-level always fall, as I remarked near the 
Weatherboard, into the head of these valleys, but into one side 
of their bay-like recesses. Some of the inhabitants remarked to 
me that they never viewed one of those bay-like recesses, with 
the headlands receding on both hands, without being struck with 
their resemblance to a bold sea-coast. This is certainly the case ; 
moreover, on the present coast of New South Wales, the nume- 
rous, fine, widely-branching harbours, which are generally con- 
nected with the sea by a narrow mouth worn through the sand- 
stone coast-cliffs, varying from one mile in width to a quarter 
of a mile, present a likeness, though on a miniature scale, to 
the great valleys of the interior. But then immediately occurs 
the startling difficulty, why has the sea worn out these great, 
though circumscribed depressions on a wide platform, and left 
mere gorges at the openings, through which the whole vast amount 
of triturated matter must have been carried away? The only 
light I can throw upon this enigma, is by remarking that banks 
of the most irregular forms appear to be now forming in some 
seas, as in parts of the West Indies and in the Red Sea, and that 
their sides are exceedingly steep. Such banks, I have been led 
to suppose, have been formed by sediment heaped by strong cur- 
rents on anirregular bottom. That in some cases the sea, instead 
of spreading out sediment in a uniform sheet, heaps it round 
submarine rocks and islands, it is hardly possible to doubt, after 
examining the charts of the West Indies; and that the waves 
have power to form high and precipitous cliffs, even in land- 
