Santa Fe new Mexican. [volume] (Santa Fe, N.M.) 1898-1951, 1901-07-25
SANTA FE, N NJ THURSDAY. 25 1901.
STRATIGRAPHICAL WORK
In NEW MEXICO
A Discussion of an Extensive Geological
Formation That Is Characteristic
Of the Southwest.
A RECENT GEOLOGICAL SURVEY

| NUVHN1 VHVuVulVhu OUNIu1
A very interesting paper on certain
geological formations in New Mexico
by Professor C. L. Herrick, was reat
today at the session Of the Information.
al Mining congress at Boise, Idaho: 1
sums up the result Of recent geologi.
cal survey by the University of New
Mexico at Albuquerque, and the New
Mexican republishes the following ex-
tracts from it:
zone of the most interesting theoret-
ical results of the stratigraphical work
of the New Mexico University geologi-
cal survey has been in the direction OF
recognizing the subdivisions Of an ex-
tensive formation that is Characters
tic of the southwest. 1t has been quite
generally customary to lump the great
series of red and greenish shales, marls
and sandstones following the carboni-
ferrous as "jura-tr -triassic' in spite of
the fact that numerous suggestions of
the presence of the Pefmian formation
have been presented.
''In central and northern Mexico the
great massive limestones of the car
boniferous show gradations of fauna
into what has been called the Permo-
carboniferous and the presence of the
characteristic fossils Especially bryo-
zoa, Fusulina robusta, Meekelia, etc.
makes this identification certain, but
till recently no characteristic fossils
have been found either in the cap CT
sandstone which we have called the
Manzano sandstone or quartzite or in
the red beds above. Tt was found pos
sible to divide the series into three ap-
proximately equal divisions on a litho-
logical basis and it was suspected that
the lower of these, containing a consid-
cradle number of lime strata interbedd-
ed with marty shale and sandstone and
capped by gypsiferous shale which at
times supports enormous beds of gyp-
sum, might be equivalent to the missing
Permian. Full confirmation of this
suspicion was secured when we found
near Tularosa, in Otero county, a mag
nificent series of characteristic Per-
mian fossils. Another locality east Of
has also yielded contir-
matory evidence. AS yet no paleonto-
logical method has been found for dis
between the Jurassic and
Triassic, though 1t seems probable that
the missing evidence will soon be
Practically the red beds
are among the most important forma-
tons in the territory as they yield cop
per, gypsum, salt and petroleum.
COPPER.
"It hardly seems too much to say
that the red beds are the original
source of nearly all the copper Of the
territory. This statement may seem
sweerf1g and 1t must be
that it rests upon theoret-
cal basis. First, as a direct source.
The primitive condition of the copper
$ in the form of sulphides and oxides
'eplacing vegetable matter in the
'hales and sandstones of the Permian
ind -triassic. This condition is
displayed in Mora county,
or example, where for many miles the
,eds of Permian and Jura- triassic are
lifted to perpendicular position west |
# the Mora anticline, which is itself |
,hiehy formed of Cretaceous strta. In |
he carbonaceous shales lying between |
f copper ore are found In such abun- |
ance as to have long served as |
ource for copper. In many cases the |
rganic nature of the original mass is |
carbonized and partly cupri- |
led. This occurrence of "tree "copper""
s it is usually called by miners, is gen.
rally over a large part of the territory.
in this widely dissent
ated state the copper is not often suf-
icently segregated to be profltably
worked except perhaps on a small
Gale. The secondary accumulations Of
opper are in reality much more im-
ortant, for it seems certain that the
.reater portion Of the copper mined
within the territory is derived from the
aaterial precipitated by organic mat
er in these sedimentary strata. The
rima1 source of the metal remains in
ny case unexplained. A very inter-
sting object lesson as to the secondary
ccumulation of copper may be seen
I the San Antreas, Caballo or San
ristobal mountains or, for that mat
ar, in any of the mountain ranges
here. the contact of the superimposed
rocks upon the granite is well
zen. In the San Andreas, for exam
lie, the entire thickness of the carboni-
erous and part of the Permian is
'und lying conformably on the gran
8, and warping assures extend
trough the entire thickness to the
ranite contact. These fissures have
cen filed from above and rarely ex- /
md to any distance into the granite.
t the granite contact is a zone where
on leechings from above have form 1
a ferruginous bed and wherever the !
ssures extend to this belt of iron-im- {
regnated conglomerate or quartzite I
lere is copper precipitation. Often {
ne masses of copper glance or oxide {
cur here but the extent of the depos- ]
is usually strictly limited and not
Itensive. 1t is not hard to read the
lemistry of the deposition of copper
the presence of iron and sulphuric ,
i'd. Where the granite bed rock
rms a basin the same priciple applies .
much more important accumula-
'n, as may be seen in the Santa Rita
strict.
Let the practical geologist ask him
II what would occur in case cuprifer- i
DIS were caught up and Incorporated !