609. Now the falling granite had in part lost its quartz and obtained
a predominance of feldspar. Furthermore as the water-globe was already
greatly collapsed, the crystals thus originated in larger drops, and
occurred besides in water already stagnant or flowing. The schistose
gefüge must have emerged as well through the preponderance of the
laminar felspar, as by the flowing of water and the attraction of the
granite-walls. This schistose granite is _gneiss_.
610. When the gneiss was thrown down the talc predominated in the
water; it now fell in the same manner with less quartz and feldspar,
and was deposited in a still more schistose form than mica-schist.
611. Granite, gneiss and mica-schist are the first that together form
a Whole, each factor whereof has been evolved in an equally perfect
manner.
LAMINATION.
612. By this active antagonism of granite to gneiss and mica-schist
the _Lamination_ of the latter is determined. Every particle of gneiss
is attracted from the granite-wall and placed in a definite direction,
corresponding to the polar operation of granite; the particles of
gneiss already deposited attract the coming ones, and so on. The parts
of the gneiss and mica-schist are not deposited upon the granite by
virtue of their dead or inert gravity, but by virtue of living polar
attraction. They are not therefore deposited in the depth of the
primary valleys, nor do they fill up the latter; but they are attracted
by the granite-walls and deposited to a greater or less extent like
laminæ of crystallization, in large perpendicular layers.
613. By these two precipitations the primary valleys were in part
filled up, and partly narrowed by the polar attraction of the walls.
The primary valleys therefore are no longer present upon the earth,
unless everything be called a primary valley that has not arisen or
been excavated by the current of water.
614. Gneiss and mica-schist have indeed taken part in the primary
crystallization, yet are, however, only its last movements, as the
water had already met with resistance, and was partly stagnant; their
mass therefore is not so purely crystallized as granite. They are not
parts of the earth's nucleus, but lie only like a crust upon it like
hollow crystals.
615. It may be said that gneiss and mica-schist originated only because
there were fathomless valleys in the granite, in which the dissevering
actions were inclosed, and extended themselves from one mountain-wall
to another, while the light could be reflected in them and heat the
earth.
616. So long as the granite was devoid of valleys, so long also did no
other formation originate. This is proved by the fact that upon the
highest mountains the granite is bare and uncovered, while this is not
the case upon its lateral walls. It is therefore the second and third
earth-rain that first originated, after the earth was heated. Gneiss
and mica-schist are, so to speak, precipitated by reflected light.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account