The Delta independent., 1913-03-28


coal-bearing table-land rising about
mile above the general level of the
country which lies to the south and
west. The West Elk mountains. near
by. group of peaks composed of ig-
neous rock. rise to attitudes of over
1900 feet above sea level and, to
sether with Grand mesa form some
of the most sublime and impressive
scenery to be found in America.
Much interest attaches to these noun
tains because of their mode of origin
and because of their influence on the
Quality of the coal. Although not far
above sea level, this area was beneath
the ocean for a long time in the Gre
years before the advent of the first
man. The sea was finally filled with
sediment and great swamps were
formed. in which vegetable matter &C.
cumulated as it is accumulating now
in Dismal Swamp. The character of
the plants. such as the figs and the
palms. whose fossil remains are now
found in the rocks. indicate that the
climate OF that time was about the
same as the present climate of For
ida or Louisiana. These beds of part
ly decaded vegetable matter were lat
er covered by sand and mud and turn
ed to coal. Still later these low lying
beds We're thrust up far above sea
80
rose from the earth's interior. some of
them reaching the surface to form
great volcanoes. while others found
lodgment within the sediments and
there consolidated into great masses
OF resistant rock msnv thousands OF
feet thick. These masses that did not
reach the surface are known as loc-
coiths.
Some Of the sedimentary rocks con
tanning coal beds were bowed up over
the loccoiths and often lie beneath
them The softer rock near the sur
face has since been eroded away and
the loccoirhs now stand as great mass
es of igneous rock. some of which
are of impressive proportions and
beautifully symetrical in outline:
others are carved bv erosion into
picturesque and fantastic forms. The
disturbance of the sedimentary rocks
that was intruded into them caused
changes in the quality of the coal that
are of great economic importance.
some of IL being transformed into an
anthracite comparable to that of Penn
sylvania.
An interesting description of this
area is found in Bulletin SO. by Willis
T. Lee. just issued by the United
States Geological Survev. The first
part of the bulletin establishes the geo
logical relations of the coal bearing
rocks. but the principal part is devot-
ed to a description of the coal beds.
their number. occurrence. thickness.
etc, The quality of the coal AT the
several localities described is indicated
by descriptions of the physical char.
acter of the chemical analysis. Great
variations occur in the quality. the
coal varying from subbtuminous and
bituminious to anthricite. The larg-
est producing mines are located at
F'loresta where anthricite is mined; a
Crested Butte. where cokeing biumin-
Gus coal is produced: and at Mount
Carbon and Somerset, where the coal
is non cokeing and bituminous. Sew
eral small mines are operating in the
etal l.laf in. l.s.s NF
product is used for local consumption
II is estimated that this region con
tains more than l6.o00.000,000 tons OF
coal in beds that are thick enough to
be of commercial value
A successful attempt is made in This
bulletin to present technical data
that are often regarded as useful auly
to the professional geologist in such
way that they can be used by a man
who has no geological training and
who is interested mianly in knowing
where coal is to be found and what
quality of coal may be expected Mt
each locality. The rock formations
are described. their appearance is IL
lustrated by reproductions of photo
graphs and their outlines are mapped
so that the coal bearing rocks can be
readily recognized on the ground.
Many sections showing the positions
of the beds one above another, meas
ured where the rocks are well ex'
posed. indicate the horizons at which
the several coal beds may be found.
For example CONSPICUOUS rock known
locally as the basal OF Rollins sand
stone is easily recognized and may
also ha fpnnd littla hplnw the hest