Durango semi-weekly herald., 1902-02-17

tion to feel assured that we have in
our midst unknown quantities of that
precious fluid, the subsequent develop
ment and production of which would
prove untold dollars added to the
wealth of the San Juan, already so rich
in other valued products wrested from
mother earth. Appended is the report
in full:
To b. N. Freeman and Frank Ed.
Qedge:
Gentlemen:--As per your request
to come to the Animas valley for the
Spurpose of making a geological report
on the physical condition relative to
the location of petroleum, artesian
water, and natural gas zone. or deposit
tributary to the city of Durango, l
herewith hand you the data collected
in making the surface examination in
part of the Durango Quadrangle.
Respectfully submitted,
R., H. DE WORE, E. NJ.
Topography.
In making a geological report it
is necessary to accompany the report
with typographical map for refer
ence as to the inequality of the sur
face ground. valleys, elevations and
streams.
In making the examinations for oil
indications l prospected territory
within radius of ten miles of this
city, the formation being confined to
the post "cretaceous period" and the
cretaceous period OF the Meozoic age
Geology.
The results Of my examination have
led me to believe that an oil horizon
exists within radius of country
bounded on the north by Junction
creek, on the southwest by Lightner
creek, and on the east by the Animas
valley.
The geological formation of this
field shows principally the Mesa
Verde" and "Mancos Shales." these
; being local terms given for the creta-
taceous period, the surface being
quite irregular, having the appearance
of saddles and troughs. The saddles
are "anticlines," the troughs syn
clines." the inconformity of which is
caused partially by erosion and par
~tially by lateral pressure. l find that
erosion has almost wholly obliterated
the Mesa Verde" shales. leaving the
Fox Hill or Mancos shales of the Gre
taceous period exposed over this en-
tire field
Geological Relations.
Petroleum oil, bitumen and natural
gas are found in all fossiliferous
rocks, from the lowest "Silurian" to
tho ,Dparr,Oct ,,ndor nor
tain conditions, among which are the
local abundance of organisms from
which these substances are formed,
and the absence of great metamor-
phism, but chiefly at the present time
from porous oil sandstones or cavities
between or within the rock strata
reached by boring.
Oil Formations.
- have said that petroleum and BIZ
tumen are found in all fossiliferous
formations where it especially
abounds; in California 1t is found
!. principally in the Tertiary; in Colora-
do it is found principally in the creta-
ceous. Surface indications Of the
presence of petroleum consist of unal-
tered rocks, white leached shales, and
sandstones, mineral springs. natural
gas. springs of petroleum oil. porous
rocks saturated with bitumen, cracks
in shale and other rocks filled with bi-
tumen, black silicified shales. The
color of the bitumens. when they ex-
list near the surface of the earth, is
black. blush black and brown.
Oil and Natural Gas.
VCarburetted hydrogen. or natural
gas. is far greater indication of the
presence of bitumen than carbonic
acid gas-the latter does not burn.
Il natural gas is found. 1t is nearly n
certain sign that somewhere near in
the formation liquid bitumens exist,
although they may be distant from the
place where the gas issues. There
fore, outcrops and anticlines can be
-vllowed from outside property into
tile property being examined and the
structure be sufficiently well demon
strated SO as to Justify person in
drilling well for oil, even II btu
mems were absent from the surface
of the land upon which the we'll Is to
be drilled and the exposures Of the
strata are but slight. The bitumens
are found In the form Of natural gas,
petroleum. oil and solid and liquified
asphaltum. The difiiculty ID the dis.
covery Of the accumulations at par
ticular places large enough to justify