The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1906-09-10
UTAH COAL BEDS
ARE DESCRIBED
Mines and Minerals Contains In
teresting Article on Utah
Coal Deposits.
GRASS CREEK IS
THE MOST IMPORTANT
Conditions Are Nearly Ideal for
Safe and Economic Coal
Extraction.

The Utah coal fields, bordering on the
eastern slope OF the Wasatch range.
some thirty miles west from Ogden, are
allied to those more extensively worked
deposits IN the neghboring State Of
Wyoming, at Almy Hanna and Rock
Springs, Some thirty to forty miles
west OF Ogden these fields are cloven by
the Weber canyon and travcrsed by the
Weber river and its tributaries, among
which Grass creek Is one of the most
important, says the Mines and Minerals.
Here, on the outcrops of coal seams
along these streams, are located the more
important coal mines Of the district. The
strata underlying the plains of Wyoming
and eastern Utah approach the Wasatch
range in a series OF parallel folds, in
creasing in abruptness and Intensity as
they near the main axis OF uplift, and
breaking at intervals in a succession Of
parallel faults. Reduplicaton OF seams
OF coal is the illuslve result. Faulting at
times may bring the upper series of coal
down from its usually high perch TO
within q few feet of a creek bottom, and
again the same movement may lift the
lower coal seam 10 an available position,
or even possibly carry 1t down out OF
sight. The coal OF these seams is of the
Ignite -bituminous type. and occurs on
sandstoneS and shales OF the Cretaceous
period. AT several different points In
the coal group are beds Of marine or
brackish water shells, In some cases
irterstratihed with the ccal seams and
occurring in the rocks Immediately be-
low them. Imprints OF fossil sea weeds,
or fucods. are not uncommon, but none
of those fossll-plant impressions, OF palm,
fern. or other semitropical forms, which
are SO common In the shales and sand
stones inclosing the coal seams In Col
orado were observed 1t would seem as X
the conditions in which the coal in the
Wasatch was deposited were OF more
maritime, or nearer the sea, character
and more subject TO temporary subsi-
deuce beneath its waters than in the
neighboring states.
Despite the apparent great thickness
OF the coal bearing series, Individual coal
seams appeared to be fewer in number
than is commonly the case. On the Grass
creek tributary TO the Weber river there
are TWO separate belts OF coal l-bearing
seams, an upper, OF two small seams,
each from three to four feet thick, sep
arated by a bed three feet thick of a
calcareous shale carrying sea shells, and
a lower, nearly 1000 feet below. con-
sistlng of a single thick seam Of coal
nine to fifteen feet thick. with an average
thickness OF eleven feet There do not
appear 10 be any. minor seams above or
below this thick seam, which lies directly
under q massive sandstone roof, with a
floor OF shale A remarkable feature Of
ible impurities. such as bone, shale or
sandstone partings, this being unusual
for a seam OF such thickness. The an
alysis also shows It's per cent OF ash to
be low, Another desirable. but not very
common feature is that the roof is of
massive sandstone instead of treacherous
shale.
Little Timbering Needed.
This frmness Of the roof obviates the
extensive use Of timbering and the coal
Is cleared off from the floor to roof
There are several mines opened at dis
tances widely apart. apparently on par
allel seams. These seams may be but
one and the same reduplicated by fault
Ing. OF these the most important lis the
Grass Creek Coal mine, which has been
successfully worked for q number of
years. Locally 1t is known as the
Church mine. because mainly owned by
the dIgnitares and members OF the Nor
mon church and worked by them. 1t is
located at the head OF the main Grass
Creek gulch, about six miles from its
junction with the Weber river canyon
The banks on the west, or left-hand side
OF the gulch, ascending the creek, are
composed Of thick massive belts of sand
stone alternating with belts of shale
these strata rising in cliffs and terraces
some 1000 feet TO the top of the noun
tain.
On the opposite side are the coal out
crops on the thick seam before men
TONED, which here averages about eleven
feet In thickness and lies between q mas
sive sandstone roof and a shale floor, the
strata dipping from eighteen to twenty
i've degrees diagonally In general east
and west direction. The most formid-
able fault is that In the lower part of
the canyon, in the old Union Pacific rail-
road property. The drop here is esti-
mated at nearly 1000 feet. bringing the
upper coal series and an underlying local
geological landmark of coarse conglom-
crate down TO within a few feet of the
level of the creek. The Grass Creek
property is trayersed by two main faults
over 1000 feet apart. but the amount of
clip al these points does not seem to ex-
ceed 100 feet The lines OF these faults
are clearly shown by the lack OF har-