.A
TABLE l-AnsnpvrerrD srRATrcRApHtccoluvN ar MoNTEzuMA,Nrw Mrxtco. ueologlc
symbols are those used in figs. 2 and 3.
B
TheCreslon
7,OOO'
Pnntoo
Drscnlptlol{
Pediment and
river gravels
Mixture of Precambrian and
younger sedimentary rock clasts
B
CarlisleShale (Kc)
Mostly dark-grayshalewith sparse
yellow-brownsandstone
bedsin
upperhalf of formation
f
Greenhorn
Limestone
Alternating beds of medium-gray
limestone with olive-gray shale
*
:.
*
Qunrenrunnv
eNoTentrnny
u
Cnerncnous "j
(Kgh)
E
a
t
Dakota
Sandstone
Three units: Lower, palegrayish-orange to very ligbt gtay
sandstone, conglomeratic to fine
grained, locally crossbedded.
Middle, dark-gray carbonaceous
shale. Upper, grayish-yellow to
grayish-olive sandstoneincfuding
coaly fragments
103
Upper half, grayish-olive shale"
Lower half , grayish-orange-pink,
medium-grained sandstonealternating with thinner beds of
siltstone and shale
4t5
Medium-dark-gray, thin-bedded
limestone interbedded with thin
greenish-gray beds of siltstone and
shale
20
(Jm)
Todilto
Limestone
(Jot)
Ocate (Entrada)
(Jot)
Sandstone
Medium-grained grayish-yellow to
pale-orange,flat to crossbedded,
friable sandstone
Chinle
Formation
Various shadesof red siltstone
ranging from medium red to
grayish red, with alternating paleolive to pale-red sandstonesand
conglomerates
(r c)
s
q
r?
Santa Rosa
Formation
1l s)
Bernal
Formation
(Pb)
E
Pale-reddish-brown, thin-bedded
siltstone, shale, and sandstone
interbedded
# San Andres
!
Limestone {
Pale-yellowish-brown, dolomitic,
denselimestone
s
$i
s
PrnvraN
Pale-reddish-brown to
yellowish-gray sandstones and
conglomerates interbedded with
thinner layers of pale-olive to
grayish-red shale
! (ps)
*
Glorieta
g
Sandstone;i
ci
Crayish-orange, fine-to-med.iumgrained, bimodal, very resistant
sandstone
g
&
&
6
t
,
fi
g
e
,*
3
nl
YesoFormation(Py)
Faulted out in Gallinas Canyon
Sangrede Cristo
Formation ( p sc)
Faulted out in Gallinas Canyon
Madera
Formation ( p sm)
Dark-yellowish-brown to
light-olive-gray, thin-bedded,
fossiliferous limestone interbedded
with pale-red to yellowish-orange
thinner bedded shales
Sandia
Formation (trsm)
Light-gray to dark-gray,
fine-grained to coarsely crystalline
limestone interbedded with paleolive to dark-gray shale
PENttsyLv.rrNtnN
I
**
*
s$
f
F
PnpceMsnraNi Precambrian
*
i
(pc )
Metasediments plus migmatites,
pegmatites,gneisses,schists,
granites, and amphibolites
5,OOO'
63
225
(Kd)
6,000
400
Medium-dark-gray shalewith
calcareous cement
Morrison
Formation
Junnssrc
40
max.
Graneros Shale (Kg)
i
Tnressrc
Turcxxrss(rr)
Fonlretlolr
4,OOO'
3,OOO'
2,OOO'
r,ooo'
FtcunE 3-GeoI-ocrc cRosssEcrroNA-B lcnoss Gx-r-rNasRrvnr nr
MoNrszurvrn,NM. Location shown on fig. 2; geologic units in
table.
least1,100ft and still havesufficientgradientto migrate
eastto the lower elevationsat the hot springs,and continueeastto the plains.
The relativelyrecentuplift of the basementrock may
r2o2 providean alternativeor additionalsourceof this heat.
The Precambrianrocks in the Montezumaarea were
deeplyburieduntil the Laramideorogeny,and thus may
retainsomeof their originalheat.Theserocksmovedto
the surfaceduring the Mioceneand post-Miocenere323 juvenation of the Rocky Mountains, and crop out,
amongother places,to the westof the hot springsarea.
Subsurfacewater passingthrough-or adjacent tothese Precambrianrocks could have its temperature
raisedto 56'C.
l ru
A third possiblesourceis relatedto the volcanismthat
has occurredin northeasternNew Mexico during the
last 8 m.y. Although the nearestvolcanicconeis 25 mi
.
o
northeast of Montezuma, severallamprophyre dikes
cutting Cretaceousrocks are exposed6 mi northeastof
93 the hot springs.Magma, relatedto the volcanics,may
exist near the percolationzone, heatingground water
that risesdue to thermal differentiation.This magma
may extendunder and to the west of the hot springs,
and contributesignificantheatto the springwater.
It is unlikely that the MontezumaHot Springscould
be
developedas a geothermalsourcefor a large elecr3.7
trical generationplant. For sucha plan to be effective,
the area would need a large volume of super-heated
steamat a temperatureof at least400' F (202"C), and a
pressureof 150psi (Summers,1968).Theseconditions
172 arenot presentat MontezumaHot Springs.
The springs,however,could be utilized to a much
greaterdegreethan they are at present.A roofed-over
swimmingpool could becomea centerfor year-round
2,000+bathing;ind someof the hot watercould be pumpedto
supply radiator heat and hot water for buildings in the
tzj
May 1979
New Mexico Geology
I \ , l e s o z o i rco c k s
P o l e o z o i cr o c k s
S T A G El - F l o t - l y i n g s e d i m e n ' l o r yr o c k so r e d e p o s i l e do v e r
P r e c o m b r i o nr o c k s
M e s o z o i c r o c x s=\
------'
P o l e o z o i cr o c x s
milling,
and
Mining,
in
operations
smelting
NewMexico
southwest
of NMBM&MR
NM,formerly
Hillsboro,
Metallurgist,
Shantz,
byRobert
and open-pit. Open-pit mining is the
method of choice in areas where ore
depositsoccur at or near the surface.
Depositsof this type occur at SantaRita
and Tyrone as large, low grade ore
bodies.Undergroundmining methodsare
usedto recoverore in narrow, nearlyvertical veins and chutes (in the caseof the
Groundhogmine at Vanadium);or when
the ore body is coveredby too muchoverburden to remove economically(in the
caseof UV Industries).Both conditions
arepresentin the area.
Therearethreemajor open-pitminesin
the district.UV Industriesat Fierro, KennecottCopperCorporationat SantaRita,
and PhelpsDodgeat Tyrone. In the pits,
ore and wasteare first broken by drilling
holesup to 14inchesin diameterand 60 ft
deep at a predetermineddistance back
from the edgeof the bench.The holesare
loadedwith explosive,then blasted.The
broken rock is loadedinto trucksby electric shovels-someof which can moveup
to 25 tons at a time (fig. l). Suchshovels,
at present, cost in excessof a million
dollars. Trucks used in the pits have
capacitiesfrom 40 to 150tons each,and
there is a trend towards even larger
trucks.
With the present ore grade at Chino
and Tyrone, about 3 tons of wastemust
be moved for each ton of ore mined.
Allowing for milling and smeltinglosses,
this meansabout 700lbs of rock must be
blasted, loaded, and hauled for each
pound of copper produced. The Chino
mine producesabout 23,0ffi tons of ore
per day, Tyroneabout46,000tons.
Because most of the underground
mines in the district have been closed
metalprices,UV's
down dueto depressed
Continental Mine at Fierro is currently
the only one of its kind in operation.
ASARCO's (American Smelting and
Refining Company) Groundhog unit at
Vanadium and Federal ResourcesCorporation'sBonneyMine at Lordsburgcan
be expectedto openiflead, zinc, and copper pricesrise.Severalsmallunderground
mines ship limited amountsof preciousmetal bearingfluxing ore to the ASARCO
Mining
smelterat El Paso,and a few other mines
produce
fluorspar on an intermittent
be
can
general,
mining operations
In
dividedinto two categories:underground basis.
The ultimate goal of mining and mineral-processingoperations in southwest
New Mexico is the Production of a
relatively pure metal or nonmetallic
mineral. Most metals occur in chemical
combinationwith other elementsto form
minerals. These minerals are dispersed
rock-formthroughoutgenerallyvalueless
S T A G E3 - C o n t i n u e d c o m p r e s s i o nc r e o t e s r u p l u r eb y
- rock
(gangue)
ore
form
to
ing
minerals
r e v e r s ef o u l l i n g
massesof sufficientsizeand value to be
processed
economically.Theseore bodies
occur in the surrounding rock or waste
and vary in sizefrom very high-gradeore
depositsa few inchesthick in someprecious-metalminesto low-gradeore deposf
o
u
l
l
i
n
g
S T A G E4 - A t t e r c o m p r e s s i o nr e l o x e d , n o r m o l
o c c u r r e di n b l o c k w e s t o f r e v e r s ef o u l l
its hundredsof feetthick in porphyrycopper mines. The mining processremoves
4-GnNERALTZED
sEcrIoN TAKEN DUE EAST
Ftcunp
the ore from the surroundingwasterock;
A
LINE.
OF
CROSS-SECTION
FRoM PoINT
milling separatesthe valuable minerals
vicinity. The most commerciallyfeasible, from the gangue; and smelting breaks
simple enterprisewould be a seriesof
down the mineralsto yield the puremetal.
greenhouses
locatedbelowthe hot springs Various companyoperationsusedifferent
and heatedyear round for growingvege- equipmentand proceduresto accomplish
tablesand flowers.
thesesteps.
A more complicated,industrialgeneraAt present,someof the major mines,
tion of electricityon a small scalemight mills, and smeltersin southwesternNew
be accomplishedthrough the use of heat Mexico are shut down as a result of
engines.Apparentlythe temperaturedifdepressed copper and zinc Prices.
ferential betweenthe hot spring waters Although significant quantities of nonand the cold water of the GallinasRiver is metallic minerals such as fluorspar were
great enoughto make heat engineseco- producedin the past, presentproduction
nomicallyfeasible,althougha substantial is limited, exceptfor the Mathis lime plant
capitalinvestmentwould be necessaryfor
midway betweenHanover and Central.
their installation.
Most of the major operatorsprovide
for
some form of public access.During
References
cited
Kennecott Copper Corporasummer
the
Baltz,E. H., 19'12,Geologicmap and crosssections
tion normallyconductstours of its operaof the Gallinas Creek area, Sangre de Cristo
Mountains, San Miguel County, New Mexico:
tions at Hurley for the generalpublic. As
U.S. Geol. SurveyMisc. Geol. Inv. Map l-673
a rule, given advancenotice, both Ken(sheetI of 2)
DodgeCorporationat
gradientsof ther- necott and Phelps
Bejnar,C. R., 1967,Temperature
to
arrangespecialgroup
are
able
Tyrone
New
Mexico,
Montezuma,
unpubsprings
at
mal
lishedpaper
tours. Other operators vary in their
LasVegas(NM) Daily Optic,20April, 1885
policiesregardingpublic tours. In addiLessard,R. H., and Bejnar, W., 1976,Geologyof
tion, PhelpsDodge, Chino, and TYrone
the Las Vegasarea: New Mexico GeologicalSocipublic lookoutsat
havereadilyaccessable
p.
ety Guidebook,27thFieldConf., 103-108
Reinerts,T. H., 1966,A historyof the Montezuma thepits.
Hot Springs,hotels, and bathhouses,1849-193'7:.
The potential hazards of abandoned
M.S. thesis,New MexicoHighlandsUniv.,97 p.
are significant and many. Do not
mines
of
Summers,W. K., 1965,Chemicalcharacteristics
mines,pits, or workings.
abandoned
enter
New Mexico's thermal waters: New Mexico
Children in all mining areas should be
Circ. 83,
Bureauof Minesand MineralResources
27p.
undercarefulsupervisionat all times.
S T A G E2 - C o m p r e s s i ocnr e o t e sL o s V e g o s s y n c r i n e
1968,Geothermics-NewMexico'suntapv. 21,no. 8
pedresource:
New MexicoBusiness,
1976,Catalog of thermal watersin New
Mexico: New Mexico Bureau of Mines and MinHydrologicReport4, p.69-72 !
eralResources
24
May l9?9
New Mexico GeologY