Graham guardian., 1919-09-19

and no evidence of underlying sedl-
mentary series was apparent. On the
east side of the valley, from the point
where the Gila river breaks into the
valley, to the Cochise county line, is
the same series of structures described
on the west side. The sandstone is
thicker bedded and more compressed
This series | traced across the entire
breadth of the Peloncillo range into the
valley of the Gila at Duncan, twenty
five miles or more distant to the east
ward. This series is evidently con-
tinuous except for fissures and open
ings through which eruptive matter
has flowed. One of these found in a
cut near the summit of the range, ex-
tending northwest and southeast along
the axis of the fold, filled with ash and
scoriaceous matter.
Throughout the Stafford District, Bear
Springs District and down the Gila
river to Geronimo, various local indica-
tions of oil exist. At Geronimo, an ap-
preciable seepage of oil occurs at the
base of a considerable cut made in the
sedimentary sana for store founda-
ton, near by is well, flowing fifty
gallons or more of salt water with con-
siderable gas. To the south and west
of Stafford, along the artesian belt,
have been bored large number of
water wells, most of which flow freely.
These waters are all more or less
charged with sulphuretted hydrogen
and yield black, muck-like precipitate
in the bitches leading from them. In
one well, about five miles southwest of
Stafford, which is now being drilled, a
| nnPknt nf nnani1ntarnH of tho
depth of 1000 feet, sufficiently strong
to blow the water from the hole in a
| jet thirty to forty feet high; this sub.
sided in half hour or so. At another
well in the near vicinity, flow of sew
enty-five gallons of water was encoun-
tered at 600 feet. With view of in
creasing the flow, the hole was sunk
sixty feet further and flow of oil was
struck sufficient that cupful could be
separated out in short time-this un-
der pressure of 600-foot column of
waterloo pounds to the square inch
is of interest. The drilling was stop
ped and the bottom of the hole plugged
up with sand to the water level, and the
oil effectually shut off. In number of
places salt beds are encountered in drill
ling with underlying beds of gypsum.
Gypsum and salt are products resulting
from evaporation Of sea water. The
gypsum always crystallizes out first
and then the salt. Some of the waters
are warm, notably Indian Hot Springs
in the northeast part of the valley and
on the east side of the Gila. The water
from this well is quite salt and has a
temperature of about 10 degrees. Con-
siderable gas escapes with the water,
presumably carbon di-oxide, and the
heat is of chemical, rather than vol
canic source.
Petroleum is stored in the porous
sedimentary rock in which it has been
formed, in porous sands and shales
Immediately above or below, in voids
formed by the shrinkage of the ordi-
nary limestone in changing to dolomite,
and in any other. fissure or cavity near
the place of its development; provided,
always, that there exists everything it
a stratum of impervious matter. Un-
der the immense pressure of earth and
water above, it tends to migrate later
ally and along the up-slope under its
cap or covering. Pressure drives it into
every tiny crack and crevice, if such
exist from one bedding plane to the
next, eventually to seep out in minute
quantities at the bottom of some deep
cut or canyon. These seepages cannot
exist where there is no oil, but the
source may be miles from where the
seepage shows. The gas and oil pockets
spoken of above are small reservoirs
along the line of tiny seepage courses
from the deeper sources below. The
Montebello Oil Field, some twelve miles
east of Los Angeles. was discovered
through boy accidentally lighting a
small flow of gas from small fault
plane in a wash on the side hill. This
was three years ago. Many millions
of dollars worth of oil have already
been taken from this field, and the
depth of the productive sands is $500
to 1000 feet.
There is no question whatever that
petroleum is product from small Or
ganisms in water, entangled in sedi-
mentary bed at the sea bottom, or that
the formation of granite, gneiss and
metamorphosed rocks is such as to pre-
clude the possibility of petroleum being
coincidentally formed; therefore, the
encountering of granite, or of highly
metamorphosed, igneous, or mneralized
rocks in the drill hole means failure IN
that hole at least, and the question of
the depth at which such rocks will be
encountered becomes one of vital mo-
ment. At Bear Springs at least 5000
to 5000 feet of sediment lies above the
granite. The granite encroaches more
into the valley as one passes to the
southeast; at the Cochise county line it
extends nearly half way into the valley. /,
Bear Springs lies four miles from the
contact of the mesa with Graham
mountain.
The presence of organic matter in |
the series is amply evidenced by the |
predominating color of the sands and
shales-light brown or yellowish- gray. |
Organic matter reduces the ferric OK /
ides (red) to ferrous oxides (ochre). /
This also accounts for the presence of |
sulphurous gases in the water of the !
wells. Organic matter reduces the |
gypsum (sulphate of calclum) to sui
phide of calcium, which yields calcium .
carbonate and sulphuretted hydrogen !
and the latter oxydizing at the surface !
precipitates sulphur or sulphur salts in
the muds of the streams.
There is in the entire valley, so far
as examined, no evidence of volcanic
or igneOus action: even where the erup-
tive overfiows on the eastern side rest
upon the eroded surface of the sands,
the heat has been insufficient to oxy-
die them beyond the forming of thin
streak along the plane of contact.
No faulting in the valley strata is
apparent, and only a slight inclination
of any of the strata. Change of water
level is indicated by changes in the
positions of the coarser matter; but the
uniformity with which the successive
layers are laid down is Indicative of a
neriOd of great trannnilitv while ihese