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formed. I t is not unreasonable to conclude that, long ere fiery
vapour and lavas began to belch forth from the Sandy Bay crater,
or the work of building up the Island commenced, this spot, where
now sitnply a mountain stream trickles over the cliff falling in
showers of spray to the bottom, was the site of a Solfatara of
no moderate size and force, emitting water, aqueous vapour, and
other gases, unaccompanied by the ejection of lava, cinders, or ashes.
Such being the case, the discharge of steam and water must have
continued with great force until after the lavas and other matter
ejected from the Sandy Bay crater, which was distant three and a
half miles south-westerly from it, had built up the Island to a
height of a thousand feet or more above the level of the sea, each
flow of lava northwards being checked in its course and so flowing
round the watery discharge of the Solfatara. At a subsequent
period, perhaps after the Island had been built up to its full height,
this Solfatara or fountain of steam, probably at a time of its
minimum power, became choked by an accumulation of fragments of
rocks and other debris; and to its imprisoned force, struggling to
obtain an outlet, may be attributed that shattering of the whole
Island, which resulted in the upheaval of its northern portion, and
the numerous rents across it, which being subsequently filled with
lavas from below formed the various dikes we now see traversing
the Island in the same direction as the line of upheaval—-viz., from
north-east to south-west. Although the large bowls at either end
of this line of upheaval—the one situated at Turk’s Cap Bay and
the other at Manatee Bay—are very crateriform in appearance, there
are no traces of lava strata which by their position can be said to
have come from them.
Turk s Cap Valley, as it is called, lying between The Barn, Grregories,
and Deadwood plain, presents an interesting part of the Island. From
Dead wood it is easiest of access. Walking being out of the question,
one has to slide down a number of deep furrows or narrow valleys
cut in the ochres and variously coloured clays for near two thousand
feet, in order to reach the bottom. The furrowed and rugged surface
of these steeps is intersected in every direction with dikes of all sizes.
I noticed some of them less than two inches wide, while others are as
large as three or four feet in thickness. In almost every case they present
marked instances of vitreous edges, showing plainly that they
were formed after the mass in which they occur had cooled. In this
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