Bonners Ferry herald. [volume] (Bonners Ferry, Idaho) 1904-current, 1922-07-06

z become sandstones. The finest par
) ticles of dust or silt which are carried
: farthest into the sea change into a
similar fashion from mud to shale
Beyond these deposits where sedi-
ments from land fail to reach these
ocean depths myriads OF invertebrate
animals live and die Most of them
have shells of calcium carbonate
(lime) that in time become compacted
and cemented into sedimentary
rock called limestone, There are of
I course all gradations possible be-
tween these types or rocks.
Particles of magma blown from
erupting volcanoes cool in air and
may be carried by the air currents to
settle in water bodies, such as lakes.
rivers and seas, thus developing a
/ true sedimentary bed from volcanic
/ material. This material should be
called volcanic dust, but is commonly
known as volcanic ash"
The other great division of rocks is
the metamorphic group. Metamor-
phic means change in form and aptly
describes the sources of origin of this
/ type OF rock. Igneous and sediment
airy rocks are converted into meta
morphic rocks by various agencies
such as pressure, heat, and movement
IN such fashion as to often destroy
any identity of the original rock. A
recrystalization occurs that develops
new minerals so that well known
minerals in common igneous rock
may be changed to rare ones in a
rather uncommon schist as a met
amorphic result. gneisses. (pronoun-
ced "nice') marble, states and quart
zltes are common metamorphic rocks.
Having dealt briefly with the ma
terlal OF the earth's crust, something
must be explained concerning the pro
cesses and agencies that affect this
crustal material.
The three dominant processes are
known as diastrophism, vulcanism
and gradation.
Diastrophism concerns the crustal
movements such as rising and sink
ing of coasts, flooding Of bays and
river valleys, folding of mountain
ranges and deyelopement of earth
quakes.
Nulcanism deals with all the move
ments Of lava such as forms the great
bulk OF many mountain ranges. build
ing volcanoes, developing ore bodies
and such processes.
Gradation is by far the most fam
iliar one to us since we have il on all
hands. 1t includes the leveling down
process as well as a building up
activity.
The deposition of all materials
whether carried by rain, rivers, waves
wind or glaciers into deltas, rivers
flood plains, alluvial cones and fans.
includes the latter process. Degra-
dation is accomplished by the same
agencies and develops river valleys.
serrated mountains. lake basin, gor-
ges, water falls, caves and countless
familiar photographic features.
The work of the atmosphere in the
form of winds, the land waters as in
streams underground waters, waves
ana currents Of the ocean supple
mented by snow, ice and glaciers. is
is sufficient to completely change the
appearance af any land body in
short space of geological time.
lt is IN considering the history
OF life on this earth that we come
into an awesome realization of geo.
logic time. The classification Of life
in the past and when it lived along
with the events of the period is called
historical geology, and hasty sketch
Of previous happenings is desirable
to help the reader understand local
geological history.
10 properly review a history of life
we must go back to it's beginning. We
must postulate continents of barren
land, at first without soil An atmos-
phere filled with swiftly moving
clouds and a climate of torrentiaI
rains and intense heat 1t was a
period of volcanic upheavals and
great areas Of sediments in deposition
TO form land masses of today.
4 The first form of life were micro
scopic and soft. AS a consequence
they left no evidence of their exist
ance. Finally as shells were devel-
oped a record of their evolution and
development was provided At
first life was very primitive and
simple As age after age passed,
different groups Of animals with
their attendant diversity of species
developed by natural selection and
evolution.
In the earlier ages of life crab-like
animals called trilobites along with
certain shelled animals dominated the
waters of the oceans and seas. As
yet no life existed on land Sue
ceeding them in power came certain
coiled she'll animals similar to the
"chambered Nautilus" of literature.
Corals and sponges gained a place
in the scheme of things.
About 300 million years Gas estim-
ated by consensus of geologic opin-
ion) after the beginning of life came
the first fishes and they in turn DOM
mated the ocean life of the earth.