Grass Valley telegraph., 1858-05-29

Constituents and Hammer of Formation.
@. NJ. Leiber, the well known Minerolo-
gist and Geologist, is now engaged in ace
ologicai and Agricultural survey of South
Carolina His first annual Report has re-
Gently been made to the Legislature Of that
State, and forms most interesting and val
liable addition to the scientific literature of
the country. A very important and inter
esting feature in the present Report, is the
! chapter which treats upon Mineral Veins
Mr.. Lieber assumes that has theory is entirely
new be that as it may, it presents many
points that are both new and suggestive
Tie study of veins " has, until recently,
receiFed very little attention either in the
old weFld or new. Biologists have hitherto
pal a1 e attention to the history of fossils
ana archaeological researches generally,
than to the study and examination of nine
fal veins, which, among all geological phe
nomena, occupy by far the most prominent
position in their application to practical pur-
poses. Indeed, it was the mineral explora-
tious Of veins which gave the first impetus to
the science ITSELF We give below, with some
slight and unimportant omissions, the entire
chapter from Mr.. Leiber's Report on the
Theory of Veins. It will be found full Of
interest both to the geologist and the miner ::
"The geologists of England and America
have generally treated veins as the results
of mere casual causes, subject to 10 Jaws,
guided by 10 rules, and, consequently, inca
pable of being subjected to any methodical
arrangement. The geologists Of the conti-
nent of Europe alone seem to have regarded
the matter in more important light; and
while much is still left for future investiga-
tions to establish, much likewise has been
attained, and many points have been deter
mined, which explain the attending phenom-
ena, and enable US to form conclusions re-
garding them often with as much certainty
as we would in the geology of stratiaed
rocks.
In most works on geology the subject of
veins is hurriedly passed over, if, indeed, it
W otNoGCO " dAA 0A0 OCuAGC4y CfSL QO NC
find them ascribing their origin to the prop
er causes. De La Beche, in his Treatise
on Theoretical Geology" maintains the DOC
trine that the metallic and other contents Of
rocks, through which the veins pass, which,
were it true, except in a few isolated and
entirely exceptional cases, would make it
necessary that these contents of the veins
should increase IN qUauUIty auu III frequency
of occurrence, the further we should leave
the veins, because it would be proportiona-
bly, more easy for those minerals, which
originally occupied a position near the mar
gin of the veins to be conducted into them,
than for those which we're further removed
from them.
Entirely the reverse is, however, the case;
those minerals which belong to the veins,
but which are found in the country, were in
reality derived from the former. The vein
crevices were the first reservoirs, and the
few scattering particles of the minerals of
the veins, which we find in the adjacent
country rocks, found their way into the lat
ter by elimination or segregation, and by
sublimation from the surcbarged vein crew
ice II the theory admitted by De la Beche
were correct, it is evident that those portions
Of the country most remote from the veins
should be selected for mining operations, as
they would undoubtedly contain the useful
minerals in the most undiminished quantity
Others have imagined that ordinary me-
tallic veins were of igneous or eruptive ori-
gin, although the regular oompoDents of the
gangues bear no resemblance to igneous
rocks of any geological period. This theory
scarcely needs refutation. In those few
cases where igneous action is evident, IL is
always ascribable to the proximity of dikes
ofigneous rocks.
That theory which is now alone admitted
as explaining the origin of veins, and which
is the only one capable of uniting the vari-
Ous phenomena connected with the distribu-
ton of their constituents, in part much re-
sembles the hypothesis Of Werner, although
designate it as entirely new, and not merely
as perfection of the one propounded by
the great Neptunist
Werner believed that veins were filed
crevices, fact now universally admitted
He also explained the origin of the substan-
ces now occupying the once vacant spaces of
the clefts, as to be found in aqueous solu-
tions, which, indeed, seems to be the ease
with all encrustation veins Of bed-like form.
He finally considered these waters 10 have
produced surface solutions which forced
their way into the fssures, and there formed
what we now find in the shape of veins In
regard to the latter point, we have aban-
doned the Wernerian opinion. We admit
with him that the minerals found in veins
were precipitated from aqueous solutions,
and that these materials have filled the an
cient ereVices, but we do not view the solu-
tions as having descended from the surface
! we regard the minerals containing the