Personal Narrative Of Travels To The Equinoctial Regions Of America During The Years 1799-1804 - Volume 2 - By Alexander Von Humboldt And Aime Bonpland.
- Page 601 of 777 - First - Home
I Saw Distinctly That,
Wherever They Crossed Each Other, The Veins Containing Mica And Black
Schorl Traversed And Drove Out Of Their Direction Those Which
Contained Only White Quartz And Feldspar.
According to the theory of
Werner, the black veins were consequently of a more recent formation
than the white.
Being a disciple of the school of Freyberg, I could
not but pause with satisfaction at the rock of Uinumane, to observe
the same phenomena near the equator, which I had so often seen in the
mountains of my own country. I confess that the theory which considers
veins as clefts filled from above with various substances, pleases me
somewhat less now than it did at that period; but these modes of
intersection and driving aside, observed in the stony and metallic
veins, do not the less merit the attention of travellers as being one
of the most general and constant of geological phenomena. On the east
of Javita, all along the Cassiquiare, and particularly in the
mountains of Duida, the number of veins in the granite increases.
These veins are full of holes and druses; and their frequency seems to
indicate that the granite of these countries is not of very ancient
formation.
We found some lichens on the rock Uinumane, opposite the island of
Chamanare, at the edge of the rapids; and as the Cassiquiare near its
mouth turns abruptly from east to south-west, we saw for the first
time this majestic branch of the Orinoco in all its breadth.
Enter page number
PreviousNext
Page 601 of 777
Words from 163350 to 163602
of 211397
