The Bozeman weekly chronicle. (Bozeman, Mont.) 1883-1889, 1888-04-11
BogeInan Goal,

Nr Geo. II. Eldr;dre has recently
made a very complete report on a nv :
brr of The coal iclls Of the Territor'
from whith the fnlIow ing description is
taken
The Bozeman coal fields lies in the
midst of the Belt range, twelve MILF
east of Bozeman, the leading town ofthe
extensive and fertile Gallatin valley.
The coal deposits occupy a large synclin.
al basin, often covered with from 3 900 10
1000 feet and more of superimposed
Cretaceous strata.
There is nothing intricate in the
general geology of the Bozeman coal field.
In the southern part We have three anti
clinal folds. Their axes lie normally a
little west of north, with a downward
curve at their northwest e~xtfemities, but
! in the easternmost aniiclinal another in
1uence has been brought to bear, causing
its axis two miles south of its northern
end to be detected to the eastward,
which strike then continues with minor
u%nimportant curves across the Yellow
stone river for at least thirty miles. The
westernmost aniiclinal il also connected
with tho other fields tn the southwest,
which join il to the high RANGES lormint
the southern wall of the Galllaiin val
ley.
Northeast of B ,senian there Is another
pref retaceotls area, that of the Hrihger
mountains, which were f. rmea by an
enormous overthrow will n reverse dip
to the westward the Older measures
lying uu two "fthc younger.
The other important development of
coal lies alorg the southern edge of this
synclinal basin, becoming quickly cover
ed by its high dip, of forty degrees and
over, by ar D thickness o fstrata,
rendering it unavailable for mining be-
yond a certain depth, however valuable
it may be.
In the Bozeman fields there are three
distinct beds of coal of notable size ; the
uppe TWO, sty led "a and "B" seams.
will best be considered first; they are
/ separated from each other by only a few
feet from ten to fifteen feet) of inter.
! posed rock. The outcrop of the eeam
, pursues a very irregular line from the
: Yellowstone to the East Gallatin, bend.
: ing around the depressed northern end
!, of the three anticlinal axes and extend.
ing well into the intervening and elevat.
oil ,nds IF thu tuo corrasnondip0 syn.
clinal basins. Just south Of the western.
most main synclinal basin, and on the
n road to the Yellowstone river, via Trail
e creek, the field is continued in n small
y be called the Trail creek field, is Of toe
small extent for large enterprises. ii
much pressed into subordinate folds, ant
is in a position accessible to q RAILROAD
only at the considerable expense Away
y accompanying the overcoming of steel
grades. The nature of the coal is pre-
cisely that of the Bozeman field. Tn
g dip of the bed varies throughout tn
n field in a general way, east of the rang
d it is from thirty seven to forty-fve de
II grees, and west of the range it varie
from fifty-seven to eighty degrees tn
, folds being more abrupt and frequen
,r This field has been prospected by phi
and tunnels quite extensively.
q The physical characteristics Of the col
10 in the Bozeman field divide it into tv
is, distinct varieties. solid block or dice
rs coal which can be mined in pieces
Ie large as the with Of the seam, and whit
or withstands weather and t~ransportatic
excellently and a friable chippy varie'
n coming out in lenticular masses, whic
d, upon being allowed to remain on Il
10 dump or upon being transported, crun
bles.into minute fragments an inch or
m long by half an inch wide, and of
n. thickness of about one eight of an inc
40 Both v~arities are bituminous and make
fair coke, though perhapsthe friable co
gives more uniformly excellent results
Mining Review.