continuous union of the basins at the foot of the Cordillera, with the
great plain of the Rio Rapel which still retains the marks of sea-action at
various levels, and their general similarity in form and composition with
the many plains near the coast, which are either similarly marked or are
strewed with upraised marine remains, fully convince me that the mountains
bounding these basin-plains were breached, their islet-like projecting
rocks worn, and the loose stratified detritus forming their now level
surfaces deposited, by the sea, as the land slowly emerged. It is hardly
possible to state too strongly the perfect resemblance in outline between
these basin-like, long, and narrow plains of Chile (especially when in the
early morning the mists hanging low represented water), and the creeks and
fiords now intersecting the southern and western shores of the continent.
We can on this view of the sea, when the land stood lower, having long and
tranquilly occupied the spaces between the mountain-ranges, understand how
the boundaries of the separate basins were breached in more than one place;
for we see that this is the general character of the inland bays and
channels of Tierra del Fuego; we there, also, see in the sawing action of
the tides, which flow with great force in the cross channels, a power
sufficient to keep the breaches open as the land emerged. We can further
see that the waves would naturally leave the smooth bottom of each great
bay or channel, as it became slowly converted into land, gently inclined to
as many points as there were mouths, through which the sea finally
retreated, thus forming so many watersheds, without any marked ridges, on a
nearly level surface. The absence of marine remains in these high inland
plains cannot be properly adduced as an objection to their marine origin:
for we may conclude, from shells not being found in the great shingle beds
of Patagonia, though copiously strewed on their surfaces, and from many
other analogous facts, that such deposits are eminently unfavourable for
the embedment of such remains; and with respect to shells not being found
strewed on the surface of these basin-like plains, it was shown in the last