Personal Narrative Of Travels To The Equinoctial Regions Of America During The Years 1799-1804 - Volume 3 - By Alexander Von Humboldt And Aime Bonpland.
- Page 250 of 635 - First - Home
Going From North To South, And First Near Marimelena,
We Find Syenite Consisting Of A Great Quantity Of Hornblende, Partly
Decomposed, A Little Quartz, And A Reddish-White Feldspar Seldom
Crystallized.
This fine syenite, the strata of which incline to the
north-west, alternates twice with serpentine.
The layers of
intercalated serpentine are three toises thick. Farther south, towards
Regla and Guanabacoa, the syenite disappears, and the whole soil is
covered with serpentine, rising in hills from thirty to forty toises
high, and running from east to west. This rock is much fendillated,
externally of a bluish-grey, covered with dendrites of manganese, and
internally of leek and asparagus-green, crossed by small veins of
asbestos. It contains no garnet or amphibole, but metalloid diallage
disseminated in the mass. The serpentine is sometimes of an
esquillous, sometimes of a conchoidal fracture: this was the first
time I had found metalloid diallage within the tropics. Several blocks
of serpentine have magnetic poles; others are of such a homogeneous
texture, and have such a glossiness, that at a distance they may be
taken for pechstein (resinite). It were to be wished that these fine
masses were employed in the arts as they are in several parts of
Germany. In approaching Guanabacoa we find serpentine crossed by veins
between twelve and fourteen inches thick, and filled with fibrous
quartz, amethyst, and fine mammelonnes, and stalactiforme
chalcedonies; it is possible that chrysoprase may also one day be
found. Some copper pyrites appear among these veins accompanied, it is
said, by silvery-grey copper.
Enter page number
PreviousNext
Page 250 of 635
Words from 68385 to 68643
of 174507