Even the iron-framed Gauchos professed
themselves glad when they reached the settlement, after our little
excursion.
The geological structure of these islands is in most respects
simple. The lower country consists of clay-slate and sandstone,
containing fossils, very closely related to, but not identical
with, those found in the Silurian formations of Europe; the hills
are formed of white granular quartz rock. The strata of the latter
are frequently arched with perfect symmetry, and the appearance of
some of the masses is in consequence most singular. Pernety has
devoted several pages to the description of a Hill of Ruins, the
successive strata of which he has justly compared to the seats of
an amphitheatre. (9/8. Pernety "Voyage aux Isles Malouines" page
526.) The quartz rock must have been quite pasty when it underwent
such remarkable flexures without being shattered into fragments. As
the quartz insensibly passes into the sandstone, it seems probable
that the former owes its origin to the sandstone having been heated
to such a degree that it became viscid, and upon cooling
crystallised. While in the soft state it must have been pushed up
through the overlying beds.
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