Mountain Home maverick. [volume] (Mountain Home, Idaho) 1906-1911, 1906-12-13
ORIGIN AND
FORMATION
Interesting and Instructive
Discussions of the
Soils of Idaho.


the Twin Falls tract, writes for the
News the following interesting pa
per on the soils OF Idaho:
The geology of Iadho with regard
TO the soils is somewhat conpli-
Gated and not very well understood
However, the relation of the soil
60 the rocks from which they were
derived can be traced with fair
ciergee of accuracy, as being COM
posed of sedimentary and eruptivc
material.
The soil is the product of disinte-
grated rock produced by the action
of heat and cold, water, drought,
air, vegetation and bacteria.
The larger area of Idaho soil is of
volcanic origin The violence of
the volcanic fire must have been
terrific, as a large portion of the
state was covered with lava and
ashes to a great depth, destroying
all life or vegetation then existing.
The later action of wind and
water, vegetable and animal life
formed and prepared the soil for
man.
This great body of nearly level
land begins in the southeastern
part of the state and extends entirely
across the southern portion, thence
northcrly on the western border as
Ear as Odds Ferry. where the Snake
river leaves Idaho
The soil formation on the bench
lands on the upper Snake river is
=al1uvial in formation, although
s5rifted in places of volcanic ash, in
sermingled with sand. Nearly all
sand or cobblcstone to an unknown
depth.
Beginning at point near Black
foot and tending to point east of
Nampa, the under strata is composed
of broken lava rock. Here the soil
as volcanic ash, having been blown
En by the wind-in other words,
rhis soil is aeoliau in formation.
This fact is clearly demonstrated
by the topography of the country
Wherever a coulee or canyon is
found the soil is very deep on the
side from which the prevailing wind
comes, while on the opposite side II
as sometimes swept bare to the rock
beneath
The soil in the Boise, Payette
and Weiser valley bench lands is OF
alluvial formation, consisting prin-
cipalty of volcanic ash, Informing lee
with sand in places and undertake
with sand and gravel.
The soil of the valleys proper is
composed of an accumulation from
the mountain sides, consisting o
Siecomposcd granite, volcanic ash
eiecayed vegetable matter and clay
having been washed down and de
posted in the valleys.
This character of soil, varying
somewhat, is found in mountain
valleys and along the rivers of Idah
sometimes only a narrow stril
on either side, and again extending
two or three miles on one or bot
sides of the rivers and mountaii
streams.
The soil of that portion OF tn
Great Salt Lake basin lying in Ide
no, while principally of eruptiv
material, the formation is Target
sedimentary. Large areas no'
under cultivation evidently wer
once lake bottoms, of which Bes
lake remains. The higher lane
are of similar composition as III
great Snake river plain
Northern Idaho is usually cor
.sidered to be that portion of ii
state lying north of Clearwat'
river.
The soil in this section is divide
into two types or basalt
material and drifts of glacial origi
Basaltic soil is found on DO
sides of the Clear water river al
extends north into Kooten
county. This soil bears evidence
sts origin-the bed of an inland sc
Since that time it has been modifi
by wind and water, and now pr
SCENTS to the eye wide ridges a
plateau, between deep canyor
showing where the water drain
off when the sea found an out
into the Columbia river, thence il
the Pacific ocean The greater p'
zion of this soil is of volcanic o
gan, although on the higher lar
,sdecomposed granite soil is found.
The soil of this section of
country is of glacial origin. E
IDENTIFY one or more of the gr
glaciers extended down into
uanhandle of the state into
vicinity of the Occur d'Alcne la
where huge drifts were formed