subsurface geology and coal resources of the pennsylvanian system ...

90 ILLINOIS BASIN COAL RESOURCES
In sec. 1 of the same township the altitude
of No. 6 coal bed in the two diamonddrill
holes (Nos. 24 and 23) is 191 and
208 feet above sea level, respectively, whei-eas
in a third hole (No. 95) to the east, it
is 15 feet below sea level, representing a
displacement of 206 to 223 feet.
The omission of beds in the drill hole,
sec. 7, T. S S., R. 9 E. (No. 165), and
differences in altitude of strata in secs. 1, 13,
and 24, T. 9 S., and R. 8 E., can better be
explained by faulting than by folding.
Between the Herald fault on the west
and the Maunie fault on the east is a downdropped
block or graben to which the names
Wabash Valley and the New Harmony
graben are applied here.24 The graben has
a maximum width of 3 miles in Gallatin
County and the boundary faults converge
toward a point about 3 miles south of the
north line of the county in sec. 15, T. 8 S.,
R. 9 E. Neither fault has been observed
at the surface.
The existence of the Herald fault is indicated
by a drill hole (McGraw-Dagley
No. 1) in sec. 2, T. 7 S., R. 9 E., White
County, where the altitude of No. 6 coal
bed is 466 feet below sea level as compared
with 240 feet below sea level in sec. 11
( Czrter-Dagley No. 1 ) . The Carter-
Dapley No. 1 starts in the downthrow block
an? passes into the upthrosv block at a
depth of 450 feet. The exact position of
the fault has not been determined becau~e
drill holes to the east are entirely in the
dov nthrow block, drill holes to the west
are in the upthrow block, and drill holes
adjacent to the fault plane do not penetrate
deep enouqh to yield critical data (Cartes-
Dagley No. 1, total depth, 1516; McGraw-
Daqley No, 1 total depth, 1876).
'rhe southernmost point to which the
Hrrald fault has been traced is in secs, 22.
23, 26,27. T. 7 S., R. 9 E , Gallatin County,
where drilling is indicative of faulting but
dc,~ not determine the exact position of the
fa ~ lt plane.
The f2rthest southern extension of the
Waunie fault on the basis of present data is
in secs. 3 and 10, T. 7 S., R. 10 E., White
County. In adjacent drill holes, 660 feet
apart, the altitude of No. 6 coal bed is - 185
feet (Sohio No. B3-Union Central Life
Z4Adopting terminology in common use by oil company
zeologists.
Ins. Co., sec. 3) and -361 feet (Sohio No.
2A-Union Central Life Ins. Co., sec. 3).
In Sohio No. 1A (Union Central Life Ins.
Co., sec. lo), 1320 feet south of Sohio No.
2A, the altitude of No. 6 coal bed is -367.
The three drill holes, Sohio IA, 2A, and
B3, cut the fault plane at depths of 1130,
1700, and 420 feet respectively. Here the
fault plane strikes N. 13 E. and dips 64
degrees N. 77 W. and the displacement of
No. 6 coal bed is 176 feet.
The Inman East fault zone runs in a
general northeast-southwest direction and
cuts the eastern edge of the Inman East pool
(figs. 13 and 14). Transections of the
major fault plane by drill holes indicate
that it dips southeast. In hole No. 199, sec.
!I, T. 8 S., R. 10 E., the major fault is
cut at an altitude of -210 feet ; in hole No.
19s in the same section 660 feet south, it
is cut at an altitude of -751 feet; and in
hole No. 196 in the same section 940 feet
southwest of hole No. 198, it is cut at an
altitude of -341 feet. On the basis of
these data it is determined that the strike
of the major fault is N. 30 degrees E., and
the dip required to obtain these differences
in altitude is 60 degrees southeast.
A drill hole in the northwest corner of
sec. 8, T. 9 S., R. I0 E. (No. 315), cuts the
major fault of the Inman East fault zone at
approximately 2500 feet and a vertical
'displacement of No. 6 coal bed of 420 feet
is indicated. Here the Tar Springs formatioa
lies in contact with what is probably the
Paint Creek formation, and the Glen Dean,
Hardinsburg, Golconda, and probably Cynress
formations are absent because of
faulting.
IGNEOUS INTRUSIONS
Igneous rocks occur fairly frequently in
Saline
where they have been encountered
in a number of coal mines.
Igneous rock occurs closest to Gallatin
County in an abandoned mine between
Eldorado and Equality on the Louisville
and Nashville Railroad (sec. 34, T. S S.,
R. 7 E.). In Saline County the rocks occur
in the form of dikes, with a width in one
~ltine of about 300 feet. The dikes are dark
" Cady, G. II., Coal resources of District V (Saline and
Gnl1;ttin co~lntics): 'Illinois Geol. Survey I\/Iin. Inv. Bull.
19, pp. 56-61, 1919.