NEW MEXICO BUREAU OF GEOLOGY AND MINERAL RESOURCES
A DIVISION OF NEW MEXICO INSTITUTE OF MINING AND TECHNOLOGY
105°37'30"W
105°35'0"W
444000
445000
36°37'30"N
446000
447000
71 66
Qfu
Qfu
QTsf
4053000
Xfg
Ta
Qfu
QTsf
Xq
Xqc
78 Tri
45
Ta
Qc
49
Tri Tri
77
Tri
Xfg
Xfg
Xa 86
77
Tri
90
60
55
20
61
59
Qal
Qal
Trt Ta
Qt7
Qt7a Qt6
Xqc
Ta
Xfg
69
Tqi
Ta
Ta
Qfy
Xq
Tqi
Tqi
Ta
Ta
Tqi
QTsf
4050000
Trp
Trp
Ta
Xq
55
40
Tqi
Ql
Xqc
75
Xq
55
55
80
Xa 40
Qm
Tgd
Ta
Qfu
Qal
Qc
Tgd
Qt6
Ta
Tqi Ta
Xq
Tgd
Qal
Qfu
Xa
Trp
Trp
Tgd
Tg
Tg
Tri
Tg
80
4049000
65
Qal
Trp
Tg Trp
Tgd
36°35'0"N
4049 000
Tg
QTsf
Trp
Trp Tg
Xqc
Tri
Trp
Trp
Tgd
Trp
Trp
Qc
25
Tg
Tgd
Tgd
Qal
Trp Tgd
Trp
Xa
Trp
Qal
Xa
Xqc
Qal
QTsf
4048 000
25
45 40
Tri
Tri
Xfg
Xa
Trp
4047000
50
35
Trp
40
Xa
90 75
Tgd
Xa
Xq
82
Xa
63
Tgd
45
45
48
Qfu
56
Qfu
44
Tri Xa
Xqc
Qfu
52
50
55
40
66
Tgd
20
Xq
55
60
20
Xfg
15
Xlg
Tgd
Tgd
50
15
15
45
Td
Qt6
Qt6
Qfy
QTsf
Qt6
Qt5
Qt4
Qt6
Qt6
Qt6
Qt6
Qt4
Qt7
Qt6
Qt7
Qfy
Td Qt6
Qt7
Qt7
Qfy
Qt6
Qt6
Qt7
Qt7
Qfy
Qfy
15
20
80
Qt7
Qt7
Qfy
Qty
30
Tapi
Porphyritic andesite and dacite (Miocene and Oligocene) - Fine-grained dark gray aphanitic and
porphyritic andesite and minor basalt. Where present, phenocrysts include hornblende, plagioclase, biotite, and little or no quartz or sanidine (Lipman and Read, 1989).
Tqk
Potassium feldspar quartz latite (Miocene and Oligocene) - Coarsely porphyritic light-gray quartz
latite containing potassium feldspar phenocrysts as long as 5 cm (Lipman and Read, 1989).
Trt
Amalia Tuff (Oligocene) - Pinkish-red welded rhyolite tuff with fiamme to 5 cm in length, abundant
phenocrysts of quartz and sanidine, and volcanic lithic fragments. Miggins et al. (2002) reported a 40Ar39
Ar sanidine age of approximately 25.1 Ma. Erupted from the Questa caldera to the east (Lipman and
Reed, 1989).
Tt
Tuff of Tetilla Peak (Oligocene) - Quartz-rich, light-colored, weakly welded, rhyolitic ash-flow tuff
containing abundant small volcanic fragments. Contains 10-30% phenocrysts of quartz, sanidine, plagioclase and sparse chloritized biotite. Lithic fragments mostly andesite and quartz-bearing rhyolite
(Lipman and Read, 1989).
Stream terrace deposits (late Pleistocene) - poorly sorted silt, sand, pebbles, cobbles, and boulders;
clasts primarily of quartzite, schist, granite, and volcanic rock types; associated soils have stage II to III
calcium carbonate development; typically present as thin (< 5 m) alluvial deposit on strath surface cut
on volcanic bedrock or Blueberry Hill deposit; associated with the Q5 surface of Kelson (1986).
Stream terrace deposits (middle to late Pleistocene) - poorly sorted silt, sand, pebbles, cobbles, and
boulders; clasts primarily of quartzite, schist, granite, and volcanic rock types; associated soils have
stage III calcium carbonate development, argillic Bt soil horizons and 10YR to 7.5YR hues in Bt horizons; typically present as thin (< 5 m) alluvial deposit on strath surface cut on volcanic bedrock or
Blueberry Hill deposit; associated with the Q4 surface of Kelson (1986).
Undifferentiated alluvial fan deposits (middle to late Pleistocene) - probably correlative with alluvial units Qt2 through Qt5; poorly sorted silt, sand, pebbles, and cobbles; not correlated to other fan
units because of lack of well-defined age control, clear stratigraphic position, and distinct lithologic
characteristics.
Alluvial fan deposits (middle Pleistocene) - poorly sorted silt, sand, and rare pebbles; clasts primarily
of granitic, intermediate volcanic, basalt, and metamorphic rock types; stage III and IV calcium carbonate development where preserved, although soil horizons are commonly affected by surface erosion;
correlative with Unit Q1p of Kelson (1986); ash probably within Qf1 deposits at locality on Ranchos de
40
Ar-39Ar method, W. McIntosh, personal
Taos quadrangle near Stakeout
communication, 1996); deposit is more than 5 m thick in northeastern part of quadrangle, and is thinner
from northeast to southwest; differentiated from unit QTbh by larger clast size (Kelson, 1986), less oxidation, poor sorting, absence of abundant manganese oxide staining, and clasts that are less weathered.
Qfu
Miggins, D.P., Thompson, R.A., Pillmore, C.L., Snee, L.W., and Stern, C.R., 2002, Extension and uplift of the northern Rio
Grande rift: evidence from 40Ar/39Ar geochronology from the Sangre de Cristo mountains, south-central Colorado
and northern New Mexico: Geological Society of America Special Paper 362, p. 47-64.
Pazzaglia, F.J., 1989, Tectonic and climatic influences on the evolution of Quaternary depositional landforms along a segmented range-front fault, Sangre de Cristo Mountains, north-central New Mexico [M.S. thesis]: Albuquerque, University of New Mexico, 246 p.
Pazzaglia, F.J., and Wells, S.G., 1990, Quaternary stratigraphy and geomorphology of the northern Rio Grande Rift, in Bauer,
P.W., Lucas, S.G., Mawer, C.K., and McIntosh, W.C., eds., Southern Sangre de Cristo Mountains: New Mexico Geological Society Guidebook, 41st Field Conference, p. 423–430.
Peterson, C.M., 1981, Late Cenozoic stratigraphy and structure of the Taos Plateau, northern New Mexico: M.S. thesis, University of Texas at Austin, Austin, Texas, 57 p.
Diabase (early Paleozoic or late Proterozoic(?)) - Nonfoliated dark gray-green medium to finegrained rocks with well preserved ophitic texture (Lipman and Read, 1989).
Xqc
Quartz monzonite of Columbine Creek (early Proterozoic) - White to gray to pale tan, moderately to
strongly foliated quartz monzonite. Recrystallized to sugary textured, non foliated rock near Tertiary
plutons. Age is 1730 Ma (Lipman and Reed, 1989).
Xq
Quartzite (early Proterozoic) - White to gray, massive, vitreous quartzite with crossbeds defined by
heavy mineral concentrations. Pervasively fractured into decimeter-scale, angular lozenges by joints,
irregular fractures, and bedding (Lipman and Read, 1989).
Xms
Biotite muscovite schist and gneiss (early Proterozoic) - Medium- to coarse-grained, thinly layered to
massive, lustrous quartz mica schist and gneiss. Commonly contains sillimanite. Locally contains garnet, andalusite and cordierite (Lipman and Read, 1989).
Xfg
Felsic gneiss (early Proterozoic) - Pale gray to orange-brown, micaceous, weakly to moderately foliated, quartzofeldspathic gneiss locally grading to micaceous quartzite. Commonly interlayered with amphibolite and amphibole gneiss (Lipman and Read, 1989).
Xa
Amphibolite (early Proterozoic) - Thinly layered to massive, fine- to coarse-grained, medium green to
dark green to black amphibolite and amphibole gneiss. Locally contains calc-silicate gneiss, biotitehornblende gneiss, felsic gneiss, and muscovite biotite schist (Lipman and Read, 1989).
Xx
Dos Equis Formation (late Quaternary to Recent) - common glassy crystals containing inscriptions
such as “cervesa mas fina” and “Alcohol by volume 4.5%”; commonly encountered in excavations on
public land, near aluminum nodules, shotgun pellet casings, and used diapers; no age control except that
most depositional mechanisms in the study area range in age from 12 to 18 years.
Xu
Proterozoic undivided (Proterozoic) - undivided Proterozoic crystalline rocks shown in cross section
only.
36°32'30"N
Qt7
Qc
Tgy
75
40
30
83
45
20
Qfu
90
45
30 Qfu
15
QTbh
Xd
4044 000
Xa
40
40
25
31
20
30
4043000
Lipman, P.W., and Reed, J.C., Jr., 1989, Geologic map of the Latir volcanic field and adjacent areas, northern New Mexico:
U.S. Geological Survey Miscellaneous Investigations Series Map I-1907, Scale 1:48000.
30
Xfg
Qfy 30
QTbh Blueberry Hill deposit (late Tertiary? to middle Pleistocene) - poorly sorted silt, sand and pebbles;
commonly cross-bedded, and stained with black manganese oxide and yellowish-orange iron oxide
coatings; oxidized; clasts are weathered or grussified; contains distinct discontinuous sandy interbeds;
clasts are granitic rock types, quartzite, metamorphic rock types, and volcanic rock types; commonly
crudely imbricated; imbrication suggests westerly flow direction in area north of Taos Municipal Airport; based on exposures at southwestern end of Blueberry Hill, thickness exceeds 25 m; may be considerably more; deposit may interfinger with unit QTsf; correlative with “Basin Fill deposit” of Kelson
(1986).
40
Xa
40
Lambert, P.W., 1966, Notes on the late Cenozoic geology of the Taos-Questa area, New Mexico: New Mexico Geological
Society, 17th Field Conference, Guidebook, p. 43-50.
Proterozoic Igneous and Metamorphic Rocks
Moraine and till (Pleistocene) - Terminal and lateral moraines, and thick valley-bottom till. Poorly
sorted and generally unstratified clay, silt, and sand containing erratic boulders; characterized by hummocky or ridged topography. Some till was mapped with colluvium (Lipman and Read, 1989).
Qc
Qfu 25
Qfu Qfu
80
Qfu
Qal
Qal
Qf6
21
90
61
75
90
40
75
Qf6
QTbh QTbh
Aphanitic rhyolite (Miocene and Oligocene) - Aphanitic to sparsely porphyritic rhyolite, otherwise
similar to Trp (Lipman and Read, 1989).
30
40
40
45 35
Qfy
Qfy
Tri
Qc
Qc
Xa
40
65 60
Qt6
Qfy
QTsf
10
50
35
35
25
15
42
50
Xqc 40
15
Qt6
40
50
25
20
20
20
42 67
4045 000
40
20
25
Qal
40 Xtr
30
Ql
80
50
Xa
40
25
60
80
QTsf
30
Xfg
60
45
87
30
Td
35
90
Ql
25
QTsf
Xa
55
65
15
40
Qt6
Stream terrace deposits (latest Pleistocene) - poorly sorted silt, sand, pebbles, cobbles, and boulders;
clasts primarily of quartzite, schist, granite, and volcanic rock types; associated soils have stage I to II
calcium carbonate development; typically present as thin (< 5 m) alluvial deposit on strath surface cut
on volcanic bedrock or Blueberry Hill deposit; associated with the Q6 surface of Kelson (1986).
Porphyritic rhyolite (Miocene and Oligocene) - White to light tan to light gray porphyritic rhyolite
typically containing 5-20% phenocrysts of quartz, sanidine, and sparse plagioclase and biotite. Occurs
as dikes 1-10 m wide and local irregular and shallow intrusions (Lipman and Read, 1989). Generally
only observed as float.
20
30
QTsf
Td
25
30
75
Qt7
Qc
Xfg
Qal
Tgd
Xa
Latite and quartz latite (Miocene and Oligocene) - Light tan to gray latite and quartz latite, often
stained rust brown, with 15-30% phenocrysts of sanidine, pyroxene and/or hornblende, sparse quartz,
and altered cubes of pyrite. Plagioclase phenocrysts to several centimeters in length are present. Occurs
as dikes up to 20 m wide and elongate intrusive masses north of the Lawrence Ranch (Lipman and
Read, 1989).
Trp
QTsf Old alluvium (late Tertiary? to middle? Pleistocene) - poorly sorted sand, pebbles, and cobbles;
clasts of basalt, quartzite, other metamorphic rock types, and volcanic rock types; locally high percentage of angular to subangular quartzite pebbles and cobbles; may be correlative with Blueberry Hill deposit (QTbh), and with unit QTg in the Arroyo Hondo quadrangle just to the west; present along piedmont between Sangre de Cristo range front and Rio Grande gorge north of Rio Hondo; correlative with
Lama Formation of Lambert (1966); contains ash layer in road cut near Cerro Negro (UTM 439989,
4044603).
Qm
75
Qfy
Qfy
Td
Qfy
Qfy
QTbh
Qt5
4046 000
Xa
45
Trp
20
Qfu
Qal
36°32'30"N
4044000
Tgd
35
50
Andesitic lava flows (Oligocene) - Purplish-gray to gray, aphanitic to porphyritic andesite lava flows
and flow breccias, with minor interbedded volcaniclastic sediments. Phenocrysts include plagioclase
and hornblende (Lipman and Read, 1989).
Alluvial fan deposits (latest Pleistocene) - poorly sorted silt, sand, pebbles, and cobbles. Probably correlative with alluvial unit Qt6.
35
Qfy
Td
Ql
Tgy
40
Trp
38
69
Qf6
Xqc
65
Xq
50
Xa
Qfu
Tgd
Xa
15
28
59
71
69
70
Qfy
45
35
75
85 52
39 54
4046000
Xa
65
61
59
63
Tqi
60
85
Xa
Xa
50
Xqc
Xa
15
59
4047 000
45
Qc Tgd
Tgd
Xa 70
Td
Qfy
Qm
Qm
62
Xa
10
Tt
QTsf
Qm
Tgd
Tgd
Ql
Xfg
Qf1
60
Tgd
Trp
Qal
Qfu
Tgd
Tg
Xfg
Trp
Trp
Xa
Tg
Qfu
Qfu
Tri
Tg Trp
Tgd
Tg
75
90
Tgd
45
65
Qal
36°35'0"N
Tgd
Tgd
Trp Tri Tg
Tgd
Tg
Trp
Qfu
Trp
Tg
Xqc
Tgd
Trp
4045000
Qt4
Trp
20
Tgd
Qfy
4048000
Qc
Tg
Qfu
QTsf
Stream terrace deposits (early to middle Holocene) - poorly sorted silt, sand, pebbles, cobbles, and
boulders; clasts primarily of quartzite, schist, granite, and volcanic rock types; associated soils have
stage I calcium carbonate development; typically present as thin (< 5 m) alluvial deposit on strath surface cut on volcanic bedrock or Blueberry Hill deposit.
Rio Hondo Pluton (Oligocene) - White to pale grayish-orange, medium- to fine- grained, massive to
locally foliated granodiorite. White to pale orange, aphanitic-porphyritic border facies has quartz
phenocrysts and local breccia. Has potassium feldspar phenocrysts up to 4 cm in size. Generally forms
rounded outcrops with abundant grus (Lipman and Read, 1989).
Kelson, K.I., 1986, Long-term tributary adjustments to base-level lowering in northern Rio Grande rift, New Mexico [M.S.
thesis]: Albuquerque, University of New Mexico, 210 p.
Xa
Tgd
QTsf
Qt5
40
Tg
Tg
Tgd
Trp
Tgd
Trp
50
80
Trp
Trp
Xq
Trp
Trp
25
Trp
Tri
Xq
4050 000
Tg
Xqc
Ta
Trp
Xa
80
Tgd
Trp
Qf6
Qc
Tgd
35
Xqc
Trp
Young alluvial-fan and stream terrace deposits (latest Pleistocene to Holocene) - poorly sorted silt,
sand, pebbles, cobbles, and boulders; clasts primarily of quartzite, schist, granite, and volcanic rock
types; associated soils have stage I calcium carbonate development; includes unit Qt8 of Kelson (1986).
Tgd
55
Xqc
65
Qt7
Qc
35
60
Qc
4051 000
Qc
55
Trp
Ql
Tgd
Qm
55
Xq
Landslide deposit (Pleistocene to Holocene) - lobate accumulations of poorly sorted soil and rock debris on slopes marked by hummocky topography and downslope-facing scarps. Derived from bedrock
and glacial deposits, and includes small earth flow, block-slump, and block-slide deposits (Lipman and
Read, 1989).
Qfy
55
40
35
65 Xqc
Tgd
Tgd
Biotite granite (Oligocene) - Granitic roof phase of the Rio Hondo pluton emplaced in the Questa caldera at about 26 Ma, during volcanism and caldera formation. Medium-grained and equigranular, with
sparse aplite and no hornblende (Lipman and Read, 1989).
15 15
45
Tgd
Tg
35
35
45
40
Tgd
Colluvial mantle on slopes, undifferentiated (middle Pleistocene to Holocene) - poorly-sorted sand,
pebbles and boulders; prevalent along bases of mountain-front facets; in northwestern part of Arroyo
Hondo quadrangle (west of Rio Grande), consists of thin mantle overlying volcanic bedrock.
Bankey, V., Grauch, V. J. S., Drenth, B., and Geophex, Inc., 2006, Digital data from the Santa Fe East and Questa-San Luis
helicopter magnetic surveys in Santa Fe and Taos Counties, NM, and Costilla County, Colorado: U.S. Geological
Survey Open-file Report 2006-1170, 4 pp with maps; available as digital product only at http://pubs.usgs.gov/
.
40
35
40
Xq
Tgd
Tri
Trp Trp
Lucero Peak Pluton (Miocene) - White to pale pink, medium to coarse grained equigranular granite
to quartz monzonite (Lipman and Read, 1989).
Tg
Tgd
Qm
45
Tgd
Tqi
Tgy
4052 000
Xa
Xa
65
20
75
Tqi
45
45
20
Xfg 60
Qal
Xa Tri
Appelt, R.M., 1998, 40Ar/39Ar Geochronology and volcanic evolution of the Taos Plateau volcanic field, northern New
Mexico and southern Colorado: MS thesis, New Mexico Institute of Mining and Technology, Socorro, NM, 58 p.
Qt
Xa
25
Xa
Tqi
QTsf
50
40
Tqi
Cerro Negro dacite (late Miocene) - Dark gray to black extensively fractured two-pyroxene dacite;
age is 5.7 Ma (McIntosh et al., 2004).
Ql
Xq
40
Tqi
Qm
62
30
Trp
Td
Qc
15
30
Trp
Trp
Xa
59
79
51
Stream channel and valley-floor alluvium, and active floodplains (Holocene) - poorly to moderately
sorted sand, pebbles, and boulders; clasts of granitic, metamorphic, volcanic, and sandstone rock types;
clasts along Rio Hondo dominated by granitic rock types, quartzite and basalt; clasts along tributaries
draining the western side of the Rio Grande dominated by volcanic rock types; weak to no soil development (correlative with unit QHa of Rawling, 2004).
4053 000
Tgd
Tgd
70
80
Qal
36°37'30"N
Qm
Xa
42
60
Tqi
Ta
55
20
Xfg
Tqi
80
Xfg
53
30
22
29
Tqi
25
Qfu
4051000
62
Xq
References:
55
46
70
15
Ta
Xa
85
Trp
Tertiary Igneous Rocks
Qm
67
62
47
55
25
36
Xa
Xms
Qt7
Qc
4043 000
65
60
79
45
75
21
85
58
67 50
Qal
Qc
Xa
Tri
Qfu
60
29
30
Tri
Qfy
4042000
65
Qf6
Xqc
Qfy
4042 000
65
Qfy
Qfu
Tgy
60
60
Qf1
4041000
4041 000
Qfu
Qfu
Qf6
Qfu
Xqc
Qfu
Qf6
4040000
Qal
4040 000
Qal
Qfu
Qt7
Qal
Qfy
36°30'0"N
Qf4
36°30'0"N
4039000
4039 000
444000
445000
446000
447000
105°37'30"W
448000
449000
450000
451000
452000
105°35'0"W
453000
454000
105°32'30"W
455000
105°30'0"W
Base map from U.S. Geological Survey 1963 from photographs taken 1962, field checked in 1963.
1927 North American datum, Polyconic Projection, reprojected to UTM projection -- zone 13N
1000-meter Universal Transverse Mercator grid, zone 13, shown in red
1:24,000
QUESTA
1
RED RIVER
NEW MEXICO
ARROYO HONDO
LOS CORDOVAS
ARROYO
ARROYO SECO
SECO
TAOS
0.5
1000
0
0
1000
2000
3000
1 MILE
4000
5000
6000
Geologic map of the Arroyo Seco
quadrangle, Taos County, New Mexico
7000 FEET
June 2010
WHEELER PEAK
1
PUEBLO PEAK
Magnetic Declination
March, 2008
9º 16' East
At Map Center
0.5
0
1 KILOMETER
CONTOUR INTERVAL 40 FEET
NATIONAL GEODETIC VERTICAL DATUM OF 1929
by
Paul Bauer and Keith Kelson 2
1
QUADRANGLE LOCATION
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.
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
New Mexico Bureau of Geology and Mineral Resources
Open-file Map Series
1
New Mexico Bureau of Geology and Mineral Resources, Socorro, NM, 87801
2
William Lettis and Associates, Inc., Walnut Creek, CA, 94596
OFGM 170
COMMENTS TO MAP USERS
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, (Dr. Peter A. Scholle,
Director and State Geologist, Dr. J. Michael Timmons, Geologic Mapping Program Manager).
New Mexico Bureau of Geology and Mineral Resources
New Mexico Tech
801 Leroy Place
Socorro, New Mexico
87801-4796
[505] 835-5490
http://geoinfo.nmt.edu
This and other STATEMAP quadrangles are (or soon will be) available
for free download in both PDF and ArcGIS formats at:
http://geoinfo.nmt.edu/publications/maps/geologic/ofgm/home.html
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.
Mapping Credits
Due to the existence of the 1:48,000 scale USGS geologic bedrock map of Lipman and Read (1989), we did
not attempt to map the Proterozoic and Tertiary crystalline rocks of Sangre de Cristo Mountains. Instead, we
scanned their map and reproduced it on our quadrangle map at 1:24,000 scale. We apologize to those authors
for presenting their geology at a larger scale than they had intended, and we applaud them for creating a fine
geologic map of such a complex and high-relief area. The scanning, digitizing and cartographic work of the
Lipman and Read (1989) map was performed by Dr. Geoffrey C. Rawling and Scott Lynch.
The current STATEMAP effort concentrated on the western half of the quadrangle, westward from the basin/
mountain contact. All of the mapping of the Sangre de Cristo fault zone is new, with the lines of Lipman and
Read (1989) simply adjusted to accommodate our new mapping. The Quaternary geology shown along the Rio
Hondo is also new, and supersedes the work of Kelson (1986).
Acknowledgments
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.
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.
NMBGMR Open-file Geologic Map 170
Last Modified 20 June 2010
Surficial Deposits
Qm
40
44
Qfy
Qc
50
68
Tgd
15
55
65
Xfg
Xfg
455000
Qc
Xa
65
Qc
60
454000
Qc
40
20
35
65
50
65
Xq
Tri
75
4052000
40
48
Tgd
Qm
Xqc
Xq
61
453000
Xvf
Xa
34
Xq
Xq
Tri
70
Xa
Qc
48
Tri
65
Xa
Qc
45 Xfg
Xa Tri
Tri
Xa Qal
Tri
Xa
Xfg
90
452000
Xa
85
Qc
50
50
36
Tri 42
9
39
Xa Tri
Xa Qal
Tri
Xa
Qt7
22
38
60 70
Qsct
Tv
Qfu
67
50
38
40
9
105°30'0"W
451000
Xq
50 Tri
Tri
Tri
Xa
450000
70
34
40
449000
42
Tri
70
Xa
Ta Qal Tv
?fu
Ta
Xa
105°32'30"W
448000
We have also compiled two bits of excellent, unpublished mapping by the late Dr. Jeffrey A. Grambling of the
University of New Mexico. This 1991 summer mapping was funded by the New Mexico Bureau of Geology &
Mineral Resources, and focused on the Proterozoic quartzites that crop out in the Cerrito Colorado and San
Cristobal Canyon areas. His linework supersedes that of Lipman and Read (1989) in those two areas.
Also included is some reconnaissance-style bedrock mapping in the southeastern quadrangle by Dr. Geoffrey
C. Rawling. His work filled in a gap at the southern end of the Lipman and Read (1989) map and added bedrock structural data to the north. His work is presented in its original form in a hydrogeologic study of the Arroyo Seco area (Rawling, 2005).
We thank Rick Ruminski of the University of New Mexico for arranging access to the lands of the D. H. Lawrence Ranch. The staff of the San Cristobal Academy graciously welcomed us onto their ranch. We also thank
the many landowners in the Arroyo Seco area who provided land status information and permitted us to traverse their properties. Dr. Tien Grauch of the USGS generously helped interpret the geology hidden within her
high-resolution aeromagnetic map of the region. We are grateful to the Governor and Warchief of the Pueblo of
Taos for granting permission to include the northern tract of their tribal lands. Scott Lynch contributed to the
original digitizing and GIS work of the map.