Qt
Qt
Qt
Qal
^cp
4012000
Qt
^cu
4
^cp
Qt
^cp
Qal
Qal
^cu
6
4
Qt
Qt
^cp
^cu Qc
Qt
Qt
Qal
^cp Qal
8
^cp 8
^cp
4
6
Qls
^cl
Qt
Qe
Qt
^cu
Qt
Qal
Qe
^cu
Qe
4
14
3
Qt
^cu
Qt
4010000
Je
Je
Js
59
Qt
Qe
Qt
Qt
Jt
Js
30
^cu
17 Qt
^cu
Tba
7
Qt
4010000
Qt
Jmb
^cu
Qp
Jmb
8
Qp
^cu
Kbc
^cu
^cu
Je
Qe
^cu
Jmb
Kbc
Jmb
Kd Kbc
Kd
Kdw
4008000
Je
36°12'30"N
^cu
Jmb
Jmb
Qc
Js
24
Je
Tau
4
Qc Tlb
Qe
6
Ti Tal
Qal
20 Qls
28
Ti
Tlb
3
3
8
47
Tau
Qal Alluvium (Holocene). Unconsolidated clay, silt, sand, and gravel deposits deposited in
major drainages and tributaries; up to 5 m thick; locally includes organic-rich sediments.
4008000
Qt
Terrace deposits (middle Pleistocene to Holocene). Alluvial silt, sand, cobble, and
boulder deposits of volcanic, granitic, and Mesozoic sandstone provenance overlying distinct
straths and underlying discrete treads related to the large modern drainages of the Rio Chama
(Gonzalez and Dethier, 1991; Gonzalez, 1993). Gonzalez (1993) recognizes as many as six
terrace levels along Rio Chama between Ghost Ranch and the map area.
Qp
Pediment gravels (middle Pleistocene to Holocene). Unconsolidated deposits of
angular to subangular pebble to boulder size blocks of Lobato Formation, Pedernal Chert,
Mesozoic sandstone, as well as rounded recycled Proterozoic quartzite, granite, and metamorphic
pebbles from the Oligocene Lower Abiquiu Formation resting on surfaces graded to the level of
the highest terraces. The largest surface, covering several square kilometers, is on La Joya del
Pedregal, which is cut on the approximate contact between the Poleo Formation and Petrified
Forest Formation of the Chinle Group. Most of the pediment surfaces are covered with eolian
silt (Qe). Approximately 1to 10 m thick.
36°12'30"N
Tau
Tau
Tba
Qc
Qls
4
4007000
Tau
Qsp Spring deposits (Quaternary?). White, fine-grained quartz sandstone, well-sorted,
angular grains, no reaction to HCl. Associated with a northeast-trending fault and characterized
by "popcorn" concretions. Appears to have formed on colluvium. < 1 m thick
Qc
Colluvium (Quaternary). Hillslope colluvial deposits composed of pebble to boulder
size unconsolidated, unsorted debris derived from local volcanic and sedimentary rocks. Qcb
designates colluvium composed mainly of Lobato basalt, Qcbt is Bandelier Tuff colluvium. Qc
refers to colluvium made up of a variety of lithologies. Up to 35 m thick.
Qls
4007000
Je
Qp
Je
Tal
Te
Jt
^cu
Js
Jt
Jt
Kd
Qt
Je
^cu
Qls
Js
Qc
Kd
Jmb
Qls
Qc
Qc
Qt
^cu
Te
Tau
Je
^cu
Jtg
^cu
Qls
Jmb
Tau
14
Jtg Je
Js
Tpc
Tal
Tau
Tal
Tpc
Tau
Tstc
20
Tba
Tsto
Tstc
Tba
Qt
Qe
^cu
8
Qt
Js
Qc
Je
Js Qal
0
Tal
Js
Kd
8
Js
Je
Qbt
Js
Js Qal
Tstc
Tsto
1
Te
Tau
Tsch
Tsto
Qc
Te
Kbc
Qc
Qc
Jmb
Tau
Tstc
Qsp
Kbc
Kbc
Kd
Tau
Tstc
Tsto
Tau
Tau
Tsch
Tsch
QTg
Tstc
Tsto
Tstc
Qc
Tsto
Qbt
Qcbt
QToc
Qcbt
Qbt
Tstc
Qaf
Qcbt
14
Qbo
Qal
Qe
Teb
Teb
Qoa Old Alluvium (Quaternary). Older alluvial deposits of gravel, sand and silt that were
deposited after the eruption of the Tshirege Member of the Bandelier Tuff along Polvadera
Creek. Dominant clast lithology is Tschicoma dacite, with subordinate amounts of rhyolite lava,
obsidian, and rare rounded pieces of Tshirege Member, Bandelier Tuff. These deposits are also
located further south along Polvadera Creek on the Polvadera Creek quadrangle (Kempter et al.,
2004). Maximum thickness is approximately 10 meters.
Qb Bandelier Tuff (Pleistocene) - pumaceous air-fall tephra, nonwelded to weakly welded rhyolitic
ash-flow tuff, and local volcaniclastic sediments; divided into two members, from younger to older:
Qbt Tshirege Member - White to orange to pink non-welded to weakly welded rhyolitic, ashflow tuff (ignimbrite). The tuff contains abundant phenocrysts of sanidine and quartz, rare
microphenocrysts of black clinopyroxene, trace microphenocrysts of hypersthene and fayalite, and
pumice fragments in a fine-grained matrix of vitric ash. The sanidine typically displays blue
iridescence. The tuff is composed of multiple flow units in a compound cooling unit (Smith and
Bailey, 1966; Broxton and Reneau, 1995). Upper flowsare generally more welded than lower flows;
includes basal white pumiceous tephra deposits (1-2 m thick) of the Tsankawi Pumice. Qbt forms
conspicuous orange to tan cliffs on both sides of Cañones Canyon in the southwest corner of the
quadrangle and along the southern .edge of the area. 40Ar/39Ar age is 1.22 ± 0.01 Ma (Izett and
Obradovich, 1994; Spell et al., 1996). Up to 60 m thick.
Qbo Otowi Member - White to pale pink, generally poorly welded rhyolitic ash-flow tuff
containing abundant phenocrysts of sanidine and quartz, and sparse mafic phenocrysts; sanidine may
display a blue iridescence. This tuff is welded in the thick section exposed in Canoñes Canyon.
Contains abundant accidental lithic fragments; consists of multiple flow units in a compound cooling
unit. The stratified pumice fall and surge deposit at base of unit (Guaje Pumice) is generally not found
in this area, but 3 cm of Guaje Pumice is preserved at the confluence of Chihuahueños and Canoñes
canyons. Qbo discontinuously fills in rugged topography on a pre Toledo caldera age volcanic surface
and can form spectacular tent rocks; upper surface quite undulatory due to erosion. Very difficult to
distinguish from upper Bandelier Tuff in hand samples; best distinguished by poorer degree of
welding, greater tendency to form slopes instead of cliffs, more abundant lithic fragments, less
abundant iridescent sanidine, and stratigraphic position beneath the Tsankawi Pumicel. 40Ar/39Ar ages
1.61± 0.01 to 1.62±0.04 Ma (Izett and Obradovich, 1994; Spell et al., 1996). Up to 180 m thick where
Qbo infilled a paleo-Cañones Canyon.
Teb
QTg Old alluvial gravels – late Pliocene(?). Alluvial to fluvial gravel and sandstone deposits
underlying the Bandelier Tuff or at unconstrained positions in the landscape. Gravel at the base of
Qbo on the west side of Chihuahueños Canyon and in Cañones Canyon includes rounded cobbles to
boulders of Lobato Formation basalt, El Ranchuelos rhyolite, Tschicoma andesite and dacite, and Ojo
Caliente sandstone. Gravel on the east side of Chihuahueños Canyon does not have Qbo directly
above it and appears to rest on Ojo Caliente sandstone. This gravel is characterized by clasts of
rounded Proterozoic granite and quartzite (recycled from lower Abiquiu Formation?), basalt, Pedernal
Chert, and sandstone. Old gravel along Polvadera Creek sits on Tschicoma andesite and underlies
Qbo. This gravel contains pebble to boulder-sized rounded Tschicoma andesite and dacite, basalt,
Pedernal chert (up to 0.5 m across), obsidian, rhyolite, and minor Proterozoic granite and quartzite. In
places along Polvadera Creek, a tan sandy matrix is dominant with respect to the conglomerate.
Gravel on top of the west end of Mesa Escoba contains rounded Lobato Formation and Tschicoma
lavas, as well as angular clasts of upper Abiquiu sandstone and Pedernal Chert. 1 to 3 m thick.
Tba
Tla
Tsch
Tsch
Tsch
Tsch
Qc
Qbt
3999000
Qbo
Teb
Qbo
Qcbt
Tsto
36°7'30"N
366000
Qbo
Qe
Qbo
367000
Qc
Qbo
Qbt
368000
106°30'0"W
Tta3
Qal
Qbo
Qcbt
Tta3
Qbo
Qcbt
Qbo
QToc QTg
369000
370000
372000
371000
Ttd1
Ttd1
Qoa
Ttd1
Qt
Qcbt
Qbo
36°7'30"N
373000
374000
375000
106°25'0"W
106°27'30"W
376000
106°22' 30"W
1000
ECHO
AMPHITHEATER
GHOST
RANCH
0
0
1000
2000
3000
4000
5000
6000
7000 FEET
CANJILON SE
1
0.5
0
1 KILOMETER
CONTOUR INTERVAL 20 FEET
YOUNGSVILLE
CERRO
DEL GRANT
CANONES
POLVADERA
PEAK
NEW MEXICO
ABIQUIU
NATIONAL GEODETIC VERTICAL DATUM OF 1929
VALLECITOS
Magnetic Declination
May, 2005
9º 59' East
At Map Center
QUADRANGLE LOCATION
New Mexico Bureau of Geology and Mineral Resources
New Mexico Tech
801 Leroy Place
Socorro, New Mexico
87801-4796
New Mexico Bureau of Geology and Mineral Resources
Open-file Geologic Map 107
Mapping of this quadrangle was funded by a matching-funds grant from the STATEMAP program
of the National Cooperative Geologic Mapping Act, administered by the U. S. Geological Survey,
and by the New Mexico Bureau of Geology and Mineral Resources, (L. Greer Price,
Director and State Geologist, Dr. J. Michael Timmons, Geologic Mapping Program Manager).
Geologic map of the Cañones quadrangle,
Rio Arriba County, New Mexico
[575] 835-5490
This and other STATEMAP quadrangles are available
for free download in both PDF and ArcGIS formats at:
http://geoinfo.nmt.edu
Qc
Qls
Qp
Qoa
Qbt
Qbo
QT g
QT oc
T eb
T ba
Km
Kd
T td
Jmj-possible
Jackpile member
Jm
T ta
T la
Tlp
T lb
T s th
Js
Jt
Je
T s to
T s tc
E ocene (? )
Ti
Tb
T au
T R cu
T R cp
T R cl
T ap
T al
T er
P ca
0.9 MILE
May, 2005
by
Shari A. Kelley, G. Robert Osburn, Charles Ferguson, Jessica Moore, and Kirt Kempter
This draft geologic map is preliminary and will undergo revision. It was produced
from either scans of hand-drafted originals or from digitally drafted original maps
and figures using a wide variety of software, and is currently in cartographic production.
It is being distributed in this draft form as part of the bureau's Open-file map series
(OFGM), due to high demand for current geologic map data in these areas where
STATEMAP quadrangles are located, and it is the bureau's policy to disseminate
geologic data to the public as soon as possible.
A
West
Cañones
Creek
La Joya del Pedregal
8000
After this map has undergone scientific peer review, editing, and final cartographic
production adhering to bureau map standards, it will be released in our Geologic Map
(GM) series. This final version will receive a new GM number and will supercede
this preliminary open-file geologic map.
DRAFT
Je
Js
TRcu
Je
TRcu
TRcp
TRcp
TRcp
Js
Trcp
Je
Je
Js+Jm
Tau
TRcu
TRcp
Tal
6000
4000
4000
A geologic map displays information on the distribution, nature, orientation, and age relationships
of rock and deposits and the occurrence of structural features. Geologic and fault contacts are
irregular surfaces that form boundaries between different types or ages of units. Data depicted
on this geologic quadrangle map may be based on any of the following: reconnaissance field
geologic mapping, compilation of published and unpublished work, and photogeologic interpretation.
Locations of contacts are not surveyed, but are plotted by interpretation of the position of a given
contact onto a topographic base map; therefore, the accuracy of contact locations depends on the
scale of mapping and the interpretation of the geologist(s). Any enlargement of this map could cause
misunderstanding in the detail of mapping and may result in erroneous interpretations. Site-specific
conditions should be verified by detailed surface mapping or subsurface exploration. Topographic
and cultural changes associated with recent development may not be shown.
The map has not been reviewed according to New Mexico Bureau of Geology and Mineral Resources
standards. The contents of the report and map should not be considered final and complete until
reviewed and published by the New Mexico Bureau of Geology and Mineral Resources. The views and
conclusions contained in this document are those of the authors and should not be interpreted as
necessarily representing the official policies, either expressed or implied, of the State of New Mexico, or
the U.S. Government.
TRcu
TRcp
6000
Kbc
Jm
8000
TRcp?
COMMENTS TO MAP USERS
Cross sections are constructed based upon the interpretations of the author made from geologic
mapping, and available geophysical, and subsurface (drillhole) data. Cross-sections should be used as
an aid to understanding the general geologic framework of the map area, and not be the sole source
of information for use in locating or designing wells, buildings, roads, or other man-made structures.
TRcu
Kd
Js
A'
East
Cañones
Fault Zone
Tba
Je
Elevation (ft)
0.45
B
West
9000
Chihuahueños
Creek
Cañoncito
Seco
Polvadera
Creek
Qbo
Qbt
Qbt
Tsto
Qbo
QTg
Qbo
Qoa
Qbt
Tba
Qbo
7000
2 m displacement
since eruption of Qbt
B'
East
Cerro Pelon
9000
Qbt
Qbo
Tsfo
Elevation (ft)
0.9
Qt
We follow the Jurassic stratigraphy for the Chama Basin outlined by Lucas and Anderson
(1998).
1:22,732
Base map from U.S. Geological Survey 1953, from photographs taken 1951, field checked in 1953.
Polyconic projection. 1927 North American datum, Reprojected to UTM projection -- zone 13.
1000-meter Universal Transverse Mercator grid, zone 13, shown in blue.
Qs p
Kbc Burro Canyon Sandstone (Cretaceous). White to tan, fine-grained, kaolinitic,
quartzose sandstone, moderately to well indurated. Contains abundant thin beds of chert and
quartz pebble conglomerate; sandstone clasts also occur. The rounded chert pebbles are usually
tan, white, and gray, and rarely black to red and much of the chert is tripolitized (Saucier, 1974;
Aubrey, 1986). Locally exhibits medium-scale cross bedding. Thin light green to pink mudstone
is interbedded with the conglomeritic sandstone, indicating recycling of the underlying Brushy
Basin mudstones (Saucier, 1974). Conspicuous cliff-forming unit, thick bedded to massive, 57
to 67m thick.
Qoa
QTg
Qcbt
Qcbt
Qes
Qbt
Qbo
Qe
Kd
Dakota Sandstone (Late Cretaceous). White, gray, and tan, fine-grained quartzose
sandstone, well sorted, locally kaolinitic, conspicuous as a cliff former, 60 to 67 m thick. The
Dakota Sandstone is well sorted, thick bedded to massive, and locally contains thin interbeds of
black, carbonaceous shale. The basal contact with the underlying Morrison Formation was
arbitrarily determined as the lowest occurrence of carbonaceous matter observed in the rock,
whether sandstone or shale.
Qe
Tta2
Qbt
Qal
Km Mancos Shale (Late Cretaceous). Dark gray and brown, weakly consolidated,
calcareous, carbonaceous shale and interlayered thin beds of fossiliferous limestone, slope
forming, 0 to 65 m thick. Lowermost part of the section only is locally present; upper contact is
an erosional unconformity of moderate relief.
Qcb
QTg
Tla
Correlation of Map Units for the Cañones 7.5-Minute Quadrangle
Ter E1 Rito Formation (Eocene). Orange-red to brick-red, hematitic, micaceous mudstone
and siltstone and lenses of fine- to medium-grained arkosic sandstone with few pebbles to
cobbles of Proterozoic granite and quartzite, slope forming. The E1 Rito Formation locally has a
2-to 10-m-thick basal conglomerate section made up of very well rounded hematitic Proterozoic
Ortega quartzite, as well as Proterozoic schist and gneiss cobbles and boulders (up to 1 m) in a
weakly to well indurated matrix of coarse ferruginous sand. Underlies the Abiquiu Formation
and overlies Cretaceous Mancos Shale, Dakota Sandstone Burro Canyon Formation, or Jurassic
Morrison Formation with erosional unconformity. Estimated 50 to 140 m thick.
4000000
Tta2
Pc
Cutler Group (Late Pennsylvanian?- Early Permian) Spencer Lucas (personal
communication) recognizes two informal formations in the Chama Basin, the Arroyo del Agua
Formation and the El Cobre Formation. Only the upper unit is exposed in the Cañones area.
Pca - Arroyo del Agua Formation- Orange red micaceous siltstone with thin, trough
cross-bedded sheet arkosic sandstone. Contains extensive calcrete nodule horizons. Little or no
conglomerate is present in this formation. This unit tends to form slopes. About 30 m exposed.
Ta
Abiquiu Formation (late Oligocene to early Miocene). Informally divided into three subunits
including, from younger to older:
Tau Upper sandstone member. White, light gray, and buff-colored fine- to mediumgrained, tuffaceous and volcaniclastic sandstone, locally conglomeratic. The upper sandstone is a slopeforming unit comprised of moderately sorted, moderately indurated volcanic detritus representing
diverse lithologies including pumice, basalt, intermediate volcanics and 25 Ma Amalia tuff. A K-Ar age
of 18.9 Ma from a basalt near the top of the unit and an Ar/Ar age of an Amalia Tuff clast of 25 Ma near
the base bracket the age of the unit (Smith et al., 2002, Moore, 2000). Up to 460 m thick
Tap Pedernal Chert member. Varicolored, white, blue-gray, black, red and yellow
cryptocrystalline, massive chert, limey chert, and limestone containing nodular chert,
conspicuous ledge former, The chert is locally interlayered with thin beds of arkosic
sandstone and conglomerate and is typically more limey at its base. 2 to 10 m thick.
Tal Lower conglomerate member. Pinkish tan to gray, generally coarse arkosic
conglomerate and fine- to medium-grained sandstone, slope forming,. The lower
conglomerate member is poorly sorted, weakly to moderately indurated, calcareous, and
characterized by well rounded pebble to boulder-size (up to 50 cm) clasts composed of
Precambrian quartzite, granite, pegmatite, gneiss and schist, as well as fine-grained limestone
and mudstone. K-Ar ages on a basalt near the base of the unit northeast of the quadrangle and
40Ar/39Ar ages on Amalia Tuff in the upper Abiquiu bracket the age of the unit between 25.1
and 27 Ma (Smith et al., 2002, Moore 2000). ~125 m thick
Ttp
Teb
Qe
Qbo
Qbo
Qt
Qls
Qcbt
Tlb
Qls
Qc
Qcbt
3999000
Tsch
Tlb
Qc
Ttd2
TRc Chinle Group (Late Triassic). Three units are mapped at the 1:24,000 scale, from younger to
older:
TRcu an upper unit that contains the Rock Point Formation and Petrified Forest
Formation. The stratigraphically highest unit in the Chile Group is the Rock Point Formation, reddish
brown to gray-red siltstone and fine-grained sandstone that is 0-70 m thick (Lucas et al., 2003). The
Petrified Forest Formation is composed of a basal red-brown laminated sandstone-dominated section
(Mesa Montosa member) and upper red-brown mudstone-dominated section (Painted Desert member)
(Lucas et al. 2003). Both the upper and lower contacts of this formation are gradational. The Petrified
Forest Formation is up to 200 m thick.
TRcp Poleo Formation – Yellow-brown to yellow- gray, medium to fine-grained, micaceous,
quartzose sandstone, conglomeritic sandstone and conglomerate. The conglomerate contains both
intrabasinal siltstone clasts and extrabasinal siliceous clasts; locally cross-bedded. This unit forms
prominent cliffs. The base of the unit is sharp (corresponds to the Tr-4 unconformity of Lucas (1993))
and the upper contact is gradational into the overlying Petrified Forest Formation, up to 41 m thick at
Abiquiu Dam.
TRcl
a lower unit that contains the Salitral Formation and the Shinarump
Formation –The Salitral Formation is an olive gray to brown sandstone to silty mudstone
near the base (Piedra Lumbre member) and a reddish brown mudstone (Youngsville member)
near the top. Upper bed of the Piedra Lumbre member, called the El Cerrito Bed, is a yellow
to brown intraformational conglomerate (Lucas et al. 2003). The Shinarump Formation, the
stratigraphically lowest unit in the Chinle Group, consists of red to orange to brown quartz
sandstone, conglomeritic sandstone, and extrabasinal conglomerate that includes clasts of
quartz, chert, and quartzite (Lucas et al., 2003). Petrified wood is common. Both the basal
and upper contacts are sharp; the basal contact corresponds to the Tr-3 unconformity of Lucas
(1993).
Santa Fe Group (late Miocene to Pliocene)
Tsth Hernandez member of the Tesuque Formation (late Miocene). A fluvial unit
(Koning et al., 2004) containing well-rounded volcanic pebbles below the Lobato Formation basalt and
above the Ojo Caliente member of the Tesuque Formationon the east end of Mesa Escoba. The gravel is
dominated by intermediate composition volcanic rocks with a few basalt and tuff clasts, along with rare
quartzite and orthoclase. A similar gravel with volcanic pebbles (mainly andesite), quartzite, glass,
sandstone and quartz appears to sit on the Lobato Formation east of Polvadera Creek. Up to 30 m thick.
Tsto Ojo Caliente member of the Tesuque Formation (late Miocene). Pink to tan-colored,
well-sorted, fine-grained feldspathic and quartzo-feldspathic sandstone of eolian origin; cross-beds
clearly indicate a prevailing wind from the west. In Cañones Canyon some exposures of the Ojo
Caliente Member are strongly cemented, forming impressive cliffs. Most of the unit, however, is poorly
consolidated, forming buff-colored sand and silt on the canyon slope; up to 100 m thick.
Tstc Chama-El Rito member of the Tesuque Formation (middle Miocene). Tan to gray
medium to coarse-grained fluvial sandstone and granule to pebble conglomerate interbedded with
orange red to red siltstone. Clasts in the conglomerate are dominated by rounded andestitc volcanics,
flow-banded rhyolite, ash flow tuff (much of which is lithic-rich Amalia Tuff), rare chert and basalt.
Petrified wood locally abundant.
Ti/Tb Black, fine-grained basalt dikes (Ti) intruding and basalt flows interbedded with the
Chama-El Rito member in Arroyo de las Frijoles.
QToc
Old colluvium (late Pliocene(?)). Angular blocks of Lobato Formation basalt beneath
and incorporated into the base of the Otowi member of the Bandelier Tuff south of Mesa Escoba. This
unit also includes Tschicoma andesite boulders beneath the Otowi member in Chihuahueños Canyon.
1 -2 m thick.
Teb
Tta1
Tlb
Qe
Qal
Je
Entrada Sandstone (Late Jurassic). White, pink, and yellowish tan, fine- to very fine-grained
quartzose sandstone, well sorted, moderately indurated, exhibits large-scale eolian dunal cross-bedding,
cliff former, 60 to 67 m thick.
Tsf
Qbt
13
Qal
Qls
Tba
Ttd1
Qal
Tstc
Qbt
Tba
Qls
Landslide deposits (Quatenary). Unconsolidated, unsorted deposits composed of
locally derived, cohesive blocks of bedrock. The large landslide on the south side of Mesa
Escoba is composed of unconsolidated Ojo Caliente sandstone overlain by blocks of Lobato
basalt and andesite. In areas to the south of Cañones Creek, many landslides are made entirely
of Bandelier Tuff blocks. Large landslides that cover many square kilometers blanket the
shoulders of Cerro Pedernal and the edges of Cañones Mesa. Sometimes the slides are
associated with a head scarp in the source area and the top of the deposit is typically hummocky;
up to 35 m thick.
Tba
Teb
Qbo
Qbo
4001000
Tsch
Tsch
12
15
55
Qe
Qls
Qcbt
Qbo
Ttd2
Qcbt Tla Qe
Tla Tsch
Qcbt
Tb
Ttd2
Tstc
Tsto
4000000
Tsch
Tsto
Qbo
Qbt
Qc+Qe
Ttd2
Tstc
Tlb
Tb
Tstc
Qe
Qcb
Teb
Ttd Ttd
Tsto
Tla
Tsto
Qc
Ttd1
Tsto
Tstc
4001000
Qc
Qls
Tstc
Tb
Qes
Tsch
Tstc
Qc
Tsch
Tlb
Tb
Tstc
4002000
Qbt
Tsch
Tsto
Qc
Tlb
Tsch
Tstc
Tb
Tstc
Tstc
Tba
Tba
Tsch
Tla
Tal
Qal
14 Tstc
Tstc
Tsch
Tstc
Tsto
Tal
Te
Qal
Teb
Qls
Tla
Te
Tb Tb
Tau
Tsto
Tstc
Tau
Tau Tau
Tba
4003000
Tb
Te
Tau
Qc
Tla
Tla
Kd
20
36°10'0"N
Tau
Tba
4
Qc
Qt
Tsch
Qc
Qc
Tb
Qc
Qal
Tau Tau
Tau
Qt
Qp
Tsch
Tsch
QTg
Tsch
Tau
Kd Kd?
Qsp Te
Kd
13
Tau
Qbt
Tau
Tsch
17
Tstc
Qc
Qc
Teb
Qt
Tau
24 35
Teb
Jmb
Jmb
4004000
Tau
Qbt
Tstc
Qc
Qt
Tau
Qes
Jmb
Tau Ti
Tau
Tba
Qc
20
Tstc
Kbc
Kbc 42
4002000
Tau
Qbo
Te
Ti
Te
Jmb
Tau
Qt
Tau
Tsch
gravel
Qc
Tau
QTg
Te
4003000
Qal
Qp
Tau
Tsto
Qt
Qc
Kbc
32
26
Qt
Jmb
9
Js
Jmb
Je
Jt
Jmb
8
Qls
Tau
36°10'0"N
Js
Js
Qc
Js
Js
Jmb
5
Te
Qal
Tstc
Qc
Tau
Qbo+QTg
Qc
Qbt
9
Qal
4005000
Tau
Qls
Tstc
Js
Jtg
Kd
Tau
Tau
Tau
Tsto
Qc
Qc
Tba
Qls
Tau
Je
Tau
Tau
Tau
Km
4004000
Tba
Tau
Jtg
6
9 Tau
Qt
Js
Kbc
Kd
Tau
Tstc
Tau
Je
Jmb
Qls
Ttd3
Qp
4005000
Qes
4006000
^cp
Jtg
4006000
Tba
Tau
Je
Jt
Jt
Js
Qes
Te
Kd
Tau
Ttd2
Te
Jt
Todilto Formation (Late Jurassic). White to gray, dominantly fine-grained, massive gypsum,
sloping-forming unit; with a 2- to 3-m-thick basal section of gray, laminated, fissile shale and/or thinbedded limestone; total unit thickness 15 to 27 m. A gray, crusty "popcorn" texture typically develops
on erosional surfaces of Todilto gypsum.
T1
Lobato Formation (7 Ma to 8 Ma). Includes basalt, andesite, and local dacite pumice occurring
as lavas exposed on Cerro Pedernal, Mesa Escoba, and Polvadera Mesa. K-Ar ages are 7.8 ± 0.7 Ma on
Cerro Pedernal, 7.9 ± 0.5 on Mesa Escoba, and 7.8 ± 0.5 Ma on Polvadera Mesa (Manley and Mehnert,
1981). An age of 8.1 ± 0.5 Ma is reported by Luedke and Smith (1978) on the lowest basalt flow on
Polvadera Mesa. The base of the Lobato flows corresponds to the T1 erosion surface of Gonzalez and
Dethier (1991) and Gonzalez (1993). The T1 surface is ~ 1110 m above the Rio Chama on Cerro
Pedernal, 730 m on Mesa Escoba, and 540 m on Polvadera Mesa (Gonzalez, 1993).
Tla Lobato andesite (Pliocene). One andesite flow is preserved on Mesa Escoba (Singer,
1985). The andesite is dark gray, fine-grained, weakly porphyritic rock with microphenocrysts of
plagioclase, clinopyroxene, olivine and quartz xenocrysts (Singer, 1985).An andesite flow is exposed in
Cañones Canyon below Chama-El Rito sandstone. This andesite is gray, with about 15-20%
plagioclase, mainly in the form of fine-needles, and pyroxene. At least 10 m thick.
Tlp Lobato pumice (Pliocene). A poorly-exposed dacitic pumice with phenocrysts of biotite
and hornblende is interbedded with Lobato Formation basalt flows on the northeastern side of Polvadera
Mesa. 30 to 40 m thick.
Tlb Lobato basalt (Pliocene). Lobato basalt from Mesa Escoba contains microphenocrysts of
olivine, augite, and plagioclase (Singer, 1985). Porphyritic olivine basalt on Cerro Pedernal has
phenocrysts of subhedral zoned labradorite (An5 , 12%, 1.5 mm); subhedral to euhedral olivine (2.5
mm), with strong iddingsite replacement and magnetite rims; subhedral augite ( 2.5 mm) containing
poikilitic plagioclase, partly twinned or with orthopyroxene reaction rims. Basal flow, 17-m thick, in a
series of flows and interlayered pyroclastic beds totaling 80 m thick (Lawrence, 1979).
Qe
Tau
Te
19
27
Tau
Tau
Tau
4009000
Tau
Tau
Tau
Tal
39
30
Tau
Qc
Tau
24
Tau
Tau
Tal
35
41
9 Qt
Qe
Qt
Tal Qc Tal
0
Tau 7
Tau
Qt
Qc
Js Tal
Tal
Qc
11
7
Qal
Qc
Tau
Kdw
Qt
18
Qt
Qt
Tau
Jmb
Kd
Km
Km
Tal
Qe
6
Jmb
Js
Jmb
25
Kd
Js
Jmb
10
Js
Qt
Js
Qe
Tal
Je
Je
Qls
Kd
Qt
16
Jm + Js
^cu
Js Je
Tt
Tschicoma Formation (3 Ma to 5 Ma). Includes andesites and local dacites occurring as
massive lavas, domes, vents, and shallow intrusives on Cañones Mesa and the northern flanks of Cerro
Pelon; informally divided into two members:
Ttd Tschicoma dacites (Pliocene). Includes hornblende- and hornblende-biotite porphyritic
rocks of diverse texture and lithology that generally overlie Tschicoma andesites. The dacitic flows on
Cerro Pelon are 2.96±0.27 Ma and contain minor augite and orthopyroxne as hydrous phases (Goff et
al., 1989). Both coarsely porphyritic and fine-grained, flow-banded, weakly porphyritic dacites are
present. The northern exposures of the dacite of Cerro Pelon (Ttd1) is gray, crystal-rich (30 to 50%)
with phenocrysts of plagioclase 9 to 13 mm across, hornblende up to 6 mm long, and biotite. At least 70
m thick. The dacite of Cañones Mesa (Ttd2) is gray, has about 20 to 30 % crystals, with plagioclase,
hornblende and biotite.
Tta
Tschicoma andesite (Pliocene). Mainly coarsely porphyritic, 2-pyroxene andesites that
occur as massive flows;about 100 m thick. One flow on the northeast side of Cerro Pelon (Tta1) is pink
to gray, 10 to 20% crystals, with plagioclase phenocrysts up to 10 mm across, with pyroxene and minor
(<1%) biotite. Pumice (Ttp) is associated with this flow. One flow at Polvadera Creek (Tta2) is black to
dark gray, slightly vesicular, 30% crystals, with apple-green and forest green pyroxene. A small flow in
Chihuahueños Canyon (Tta3) is crystal-poor (5-10%), fine-grained, gray with plagioclase and pyroxene
phenocrysts.
Qt
Je
Js
Summerville Formation (Late Jurassic). The basal 8 to12 m of this unit consists of white to
light gray, fine- to very fine grained quartzose sandstone, thin-bedded, containing small-scale ripple
marks, gypsum blade casts, and soft-sediment deformation. The basal sandstone is overlain by
variegated maroon and gray quartzose to subarkosic siltstone. This unit tends to form slopes. The upper
contact is the stratigraphically highest maroon siltstone that contains abundant pedogenic carbonate
concretions, located above the Bluff Sandstone interval. The Bluff Sandstone, a tan fine grained, crossbedded sandstone that is about 10 m thick, is included in the Summerville Formation on this map.
Approximately 60 m thick.
Tg
Tertiary alluvial gravels (Pliocene). Gravel at the northern tip of Cañones Mesa, apparently
under the basaltic andesite of Cañones Mesa and above the Jurassic Summerville Formation, contains a
mix of Proterozoic quartzite cobbles, with minor granite, Pedernal Chert, and volcanic pebbles. About 3
m thick.
Qe
Eolian silt (Holocene). Unconsolidated windblown tan to brown silt and clay deposited
in low-elevation spots and on pediment surfaces. Usually 1 to 3 m thick, but can be 10 m thick.
Qt
5
The most significant findings made during this project include (1) the recognition of
previously unmapped Pliocene Tschicoma lava domes and flows; (2) establishing that
Cañones Mesa is formed by a ~2.8 Ma basaltic andesite that overlies the ~3.0 Ma dacite of
Cerro Pelon and underlies El Alto basalt; (3) discovery of a dacitic pumice layer within the
Miocene Lobato Formation; (4) observation that the Hernandez member of the Miocene
Tesuque Formation is interbedded with Miocene Lobato Formation basalt and andesite on
Mesa Escoba; (5) mapping of a low-angle (25 to 30°), north-dipping, possible
intraformational unconformity within the Oligocene to Miocene upper Abiquiu Formation;
(6) observation of Eocene El Rito Formation cutting through Cretaceous Dakota Sandstone
into the underlying Cretaceous Burro Canyon and Jurassic Morrison Formation along the
west side of the area; (7) discovery of an outcrop of possible Jackpile member of the
Jurassic Morrison Formation, a unit not usually found in the Chama Basin.
9
Qt
Qt
Jmb
Tba Basaltic andesite of Cañones Mesa. (Pliocene). This lava, which caps Cañones Mesa, is
generally more crystal poor than a typical Tschicoma lava, containing < 5% phenocrysts of plagioclase,
pyroxene, and olivine. The lava is composed of at least two flows, characterized by basal block and ash
features, and is platy in outcrop. K-Ar ages are 2.8 ± 0.7 Ma and 2.8 ± 0.5 Ma on Cañones Mesa
(Manley and Mehnert, 1981). Overlain by El Alto basalt and underlain by dacite of Cerro Pelon. The
base of the basaltic andesite on Cañones Mesa, which is ~380 m above the Chama River, corresponds to
the T4 erosion surface of Gonzalez and Dethier (1991) and Gonzalez (1993). Averages about 100 m
thick.
Tal
18
Jmb 19
Js Js
Qal
^cu
^cu
^cu
8
Te
Jmb
^cp Qt
5 ^cu
^cu
^cu
^cu
Je
12
Ti
^cl
Qt
^cp ^cp
Qt
Tal
Js
Pca
Qt
Qal
Js
Jmb
Tg
Tg
4009000
Qt
10
^cu
33
Qc
Qt
^cl
Qt
Je
Js Jt
Tg
3
^cp
^cl
Qt
Qal
4011000
Jmb
9
Js
Je
Qt
Js
5
Qt
3
Qt
^cu
Qc
2
^cu
Qt
Qt
^cp
^cu
Qa
^cu
14
Qt
Qt
3
9
Qt
Qt
Qt
Pca
41
Jmb
6
11
Qt
8
^cu Qal
Qt
Qt
^cl Pca
Jt
Pca
^cu
Pca
4
6
Qt
^cp
Qc
Js
^cl
Pca KbcJmb
Jmb
Qt
^cp 9
Qt
Pca
Qt
Qt
Qal
4011000
Qp
^cl
4012000
Qc Jt
Qc Je
Qt
12
^cu
Qc
2
4
9
6
^cu
3
Pca
9
10
^cu
^cu
Qt
Qt
Qt
5
5
4 4 Qal 13
12
Qc
Qp
Qt
Qls
Qt 11
Qt
Qe
^cu
^cp
Qal
Qt
^cu
0
Qal
C R E T AC E OUS
Qt
^cp
^cp
^cu
J UR AS S IC
^cu
Qt
T R IAS S IC
36°15' 0"N
36° 15' 0 "N
P E R MIAN
376000
375000
374000
Holocene
373000
372000
P leistocene
371000
370000
P liocene
369000
Miocene
368000
367000
Jm
Morrison Formation (Late Jurassic). Shown on the map as an undivided unit, two members
are recognized in the map area from younger to older, the subunits are:
Jmj - Jackpile sandstone in the Brushy Basin Member. Orange red, fine-grained, moderately sorted,
carbonate cemented quartz sandstone with abundant clay matrix. Goethite concretions. Quartz angular
to subround. Medium to thin bedded. The sandstone just above the underlying green Brushy Basin
siltstone is a granule sandstone to pebble conglomerate with clasts of reworked Morrison siltstone, chert,
and quartzite. Conglomeritic material in the Jackpile sandstone is usually sparse and is usually limited
to the base of the unit (Aubrey, 1986).
Jmb - Brushy Basin Member. Variegated green to reddish orange to dark reddish brown siltstone and
grayish-white to gray, very fine-grained subarkosic, cross-bedded sandstone, slope forming, 110 m
thick.
Oligocene to
E arly Miocene
366000
106°22' 30"W
106°25'0"W
106°27'30"W
106°30'0"W
Teb El Alto Basalt (Pliocene). Dark brown to black, vesicular basalt with phenocrysts of
plagioclase, pyroxene and olivine. Overlies the basaltic andesite of Cañones Mesa and appears to emit
from a vent on the north side of Cerro Pelon. K-Ar age of 3.1 ±0.7 Ma (Manley and Mehnert, 1981). Up
to 120 m thick.
The Cañones quadrangle lies at the boundary between the Rio Grande rift and the
Colorado Plateau, and includes the Cañones fault zone, an important down-to-the-east
structure (among many) that marks the transition between these two provinces. This
transition zone between provinces extends to the west into the Youngsville and Coyote area
(Lawrence, 1979: Kelley et al., 2005). The northern part of the Miocene to Pleistocene
Jemez volcanic field covers about 35 percent of the southern and eastern portions of the
area. A wonderfully complex history of late Paleozoic to Mesozoic deposition, Laramideage deformation, erosion, and deposition, Rio Grande rift deposition and faulting, as well
as Jemez volcanic field eruptive activity and subsequent deformation is preserved in this
special place.
QUAT E R NAR Y
A DIVISION OF NEW MEXICO INSTITUTE OF MINING AND TECHNOLOGY
T E R T IAR Y
NEW MEXICO BUREAU OF GEOLOGY AND MINERAL RESOURCES
Tla
Tstc
Qbo
Tsto?
Tsto?
Tla
Tta
Ttd1
Teb
Tba
Ttd1
7000
??
5000
5000