NMBGMR Open-file Geologic Map 81
Last Modified 07 AUGUST 2006
NEW MEXICO BUREAU OF GEOLOGY AND MINERAL RESOURCES A DIVISION OF NEW MEXICO INSTITUTE OF MINING AND TECHNOLOGY
106°12'30"W
389000
106°10'0"W
390000
391000
392000
Description of Map Units to Accompany
Geologic Map of the Chilili 7.5-Minute Quadrangle
106°7'30"W
393000
394000
395000
396000
397000
Description of Map Units
Pennsylvanian
Bruce D. Allen, May 2004
Qcr
&ws
Qvac
&ws
Qvac
Qa
&ws
Qvac
3
&wp
&wp
Qvac
Qvac
Qa
Qcr
Qcr
3873000
5
Qvac
Qa
1
Qvac
&ws
Qa
Qcr
Qcr
Qcr
Qvac
&ws
&ws
Qcr
Qcr
&wp
Qcr
Qcr
Qa
2
3
Qcr
Qcr
Qcr
Qcr
&wp
Qcr &ws
Qcr
Qcr
Qp
Qcr
Qcr
Qcr
Qcr
Qcr
&ws
&wp
&ws
Qcr
&ws
Qa
3867000
&wp
&wp
&wp
1
&ws
&ws
Qcr
&ws
2
&ws
&ws
&wp
Qcr
1
Qa
Qvac
&wp
&wp
&ws
&wp
&wp
&wp
&ws
Qvac
Qcr
&wp
Qcr
Qcr
Qcr
&ws
&wp
Qcr
Qcr
&ws
Qvac
34°55'0"N
&wp
Qcr
Qcr
&wp
Qcr
Qcr
&ws
&ws
Qvac
&ws
&wp
&wp
Qvac
34°55'0"N
Qcr
Qa
&ws
Qcr
&wp
3863000
Qcr
Qcr
Qa
Qcr
&wp
&ws
Qcr
&ws
2
&ws
Qa
&wp
Qcr
Qcr
Qa
&wp
3863000
Qcr
2
&wp
Qcr
&ws
Qa
Qcr
&ws
Qvac
Qp
Qcr
&ws
&ws
Qvac
&wp
&ws
Qvac
&ws
2
&wp
&ws
&wp
Qcr
&wp
Qa
Qcr
1
3
&wp
Qcr
&ws
Qcr
Qvac
&ws
1
Qcr
Qcr
Qcr
Qcr
Qcr
&wp
Qa
Qcr
Qcr
Qcr
2
&wp
Qcr
Qcr
Qcr
Qa
34°52'30"N
388000
&wp
Qa
Qa Qcr
&wp
Qcr
389000
106°15'0"W
Qcr
Qcr
Qa
Qcr
387000
Qcr
Qcr
Qa
Qcr
386000
Qcr
&wp
&wp
&wp
Qcr
Qcr
Qcr
Qcr
&ws
&ws
3861000
&wp
&wp
Qcr
Qvac
Qvac
Qa
&wp
Qvac
&ws
&ws
3862000
Qcr
&ws
3861000
Qa
&wp
&ws
&ws
3860000
&wp
Qcr
&wsQvac
&wp
Qvac
&wp
Qcr
Qvac
3862000
3864000
Qa
Qcr
&wp
Qvac
Qvac
&ws
&ws
3865000
&wp
Qcr
Qcr
Qcr
Qa
&wp
Qa
Surface exposures of bedrock in the map area belong to the Madera Group. The
Middle to Upper Pennsylvanian (Desmoinesian-Virgilian) Madera Group includes marine
and marginal-marine carbonate and siliciclastic sediments consisting of interbedded
limestone, shale, sandstone, and minor conglomeratic sandstone. The thickness of the Madera
Group in the vicinity of the Sandia and Manzano Mountains ranges from about 400 m
(Kelley and Northrop, 1975) to perhaps 580 m (Read et al., 1944, measured section 14), or
more, and has traditionally been divided (e.g. Read et al., 1944; Kelley and Northrop, 1975)
into a lower unit containing a large proportion of limestone ("lower gray limestone"), and an
upper unit containing a large proportion of siliciclastic sediments ("upper arkosic
limestone"). The Madera Group gradationally overlies rocks of the Middle Pennsylvanian
(Atokan) Sandia Formation, which is also marine to marginal-marine in origin and is
dominated by siliciclastic sediments. The Sandia Formation generally overlies Proterozoic
crystalline rocks in the area, although a thin (up to 20m thick) sequence of limestone and
shale deposited during Mississippian (?) time is present between the Sandia Formation and
Proterozoic crystalline rocks at several localities in the Sandia and Manzano Mountains
(Kelley and Northrop, 1975). The Madera Group is gradationally overlain by the Bursum
Formation (Virgilian-Wolfcampian), which, in the Manzano Mountains, consists of
interbedded siliciclastic sediments with a few thin limestone interbeds. The Bursum
Formation was probably deposited as the last of the Pennsylvanian seas withdrew from the
area, and is overlain by continental redbeds of the Abo Formation.
Subdivision of the Madera Group in the Manzano Mountains was formalized by
Myers (1973), who elevated the Madera to group status and designated two formations
within the Madera- the Los Moyos Limestone and the overlying Wild Cow Formation (Myers
also included the Bursum Formation in the Madera Group). The Los Moyos Limestone and
Wild Cow Formation generally correspond to the earlier concept of lower gray limestone and
upper arkosic limestone members of the Madera "Formation". As noted by Myers (1973), the
Los Moyos and Wild Cow Formations are likely equivalent to the Gray Mesa and Atrasado
Members, respectively, of the Madera "Formation" as defined by Kelley and Wood (1946) in
the vicinity of the Lucero uplift. Recent recommendations to simplify the stratigraphic
nomenclature of Pennsylvanian rocks in New Mexico (Kues, 2001) suggest that the
formation names Los Moyos and Wild Cow may eventually be abandoned in favor of the
names Gray Mesa and Atrasado, which have precedence.
Myers (1988) concluded that most of the Los Moyos Limestone lies within the
fusulinid zone of Beedeina, indicating that the unit is correlative to Desmoinesian strata of
the mid-continent. The overlying Wild Cow Formation lies within the zone of Triticites, and
corresponds for the most part to Missourian and Virgilian strata of the mid-continent. The
Wild Cow Formation was subdivided by Myers (1973) into three members. The three
members in ascending order are the Sol se Mete, Pine Shadow, and La Casa. Each of the
three members conceptually consists of a basal sequence containing an abundance of
siliciclastic beds that grade upward into capping intervals dominated by carbonate-shelf
limestone beds.
Subdivision of the Madera Group on the geologic map and cross sections uses the
nomenclature of Myers (1973). Surface exposures in the map area are limited to portions of
the Sol se Mete and Pine Shadow Members of the Wild Cow Formation.
&wp
&wp
Qvac
Qa Qvac
Kues, B.S., 2001, The Pennsylvanian System in New Mexico- overview with suggestions for
revision of stratigraphic nomenclature: New Mexico Geology, v 23, p. 103-122.
General
Qa
&wp
Qcr
Qvac
Qcr
Qcr
Qa
390000
391000
3860000
Qa
392000
393000
106°12'30"W
394000
395000
Qa
396000
106°10'0"W
1
MORIARTY NORTH
0.5
0
1 MILE
NEW MEXICO
940
CHILILI
CHILILI
0
MILBOURN RANCH
Read, C.B., Wilpolt, R.H., Andrews, D.A., Summerson, C.H., and Wood, G.H., Jr., 1944,
Geologic map and stratigraphic sections of Permian and Pennsylvanian rocks of parts
of San Miguel, Santa Fe, Sandoval, Bernalillo, Torrance, and Valencia Counties,
north-central New Mexico: U.S. Geological Survey, Oil and Gas Investigations
Preliminary Map 21, scale 1 in = 3 mi.
397000
106°7'30"W
Contact (approximate)
940
1880
2820
3760
4700
5640
6580 FEET
Geologic map of the Chilili
quadrangle, Bernalillo and Torrance
Counties, New Mexico.
U
Fault, dashed where inferred, dotted where covered. Relative displacement
across fault,"D" on downthrown side, "U" on upthrown side
D
MORIARTY SOUTH
1
TAJIQUE
New Mexico State Engineer, 1967, Thickness of alluvium, valley fill and lake deposits,
Estancia underground water basin: New Mexico State Engineer Office, Open-file
Map, scale 1 in = 2 mi.
34°52'30"N
ESTANCIA
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
Magnetic Declination
March 20,2003
10º08' East
At Map Center
0.5
0
1 KILOMETER
3
Qa
Qp
Qvac
Qcr
Pwp
Pws
Pm
2
CONTOUR INTERVAL 20 FEET
by
Bruce Allen 1
NATIONAL GEODETIC VERTICAL DATUM OF 1929
New Mexico Bureau of Geology and Mineral Resources
Open-file Map Series
X
Strike and dip of bedding plane, dashed where approximate
May 2004
1
Correlation of map units, Chilili 7.5' quadrangle
Monoclinal flexure
NMBGMR, 801 Leroy Place, Socorro, NM, 87801
OFGM 81
A'
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
A
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.
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.
Line of Cross section
A
A'
8000
Pwp
7000
Elevation (ft)
ESCABOSA
Myers, D.A., 1988, Stratigraphic distribution of fusulinid foraminifera from the Manzano
Mountains, New Mexico: U.S. Geological Survey Professional Paper 1446, 65 p.
Ps
1:24,000
EDGEWOOD
Myers, D.A., 1973, The upper Paleozoic Madera Group in the Manzano Mountains, New
Mexico: U.S. Geological Survey Bulletin 1372-F, 13 p.
Qp
Qvac
&wpQa
Qcr
Qa
Qcr
Base map from U.S. Geological Survey1975.
1927 North American datum, UTM projection -- zone 13N
1000-meter Universal Transverse Mercator grid, zone 13, shown in red
SEDILLO
Kelley, V.C., and Wood, G.H., 1946, Lucero uplift, Valencia, Socorro, and Bernalillo
Counties, New Mexico: U.S. Geological Survey, Oil and Gas Investigations
Preliminary Map 47, scale 1 in = 1 mi.
Bedrock Map Units
&wp
&wp
&wp
1
3864000
Qa
&wp
&wp
Qa
Kelley, V.C., and Northrop, S.A., 1975, Geology of Sandia Mountains and Vicinity, New
Mexico: New Mexico Bureau of Mines and Mineral Resources, Memoir 29, 135 p.
3866000
&wp
Qcr
References
&wp
&wp
&wp
&wp
Qcr
3865000
Qcr
Qcr
Qvac
Qvac
&wp
&wp
3866000
Qcr
&ws
Qcr
Qcr
Alluvium, colluvium, and residuum on valley backslopes and interfluvial
summits in bedrock uplands. Holocene to middle Pleistocene (?). Predominantly silt, clay,
and sand. Derived from weathering of the Madera Group (residuum on relatively flat-laying
areas), and from downslope transport of weathering products. Mapped where accumulations
cover extensive areas and are sufficiently thick to support large areas of grass cover. Also
includes areas of unmapped bedrock exposure. Unit ranges from less than one to several
meters in thickness.
&wp
&ws
Proterozoic
XuProterozoic crystalline rocks, undifferentiated (cross sections).
Qcr-
3867000
&ws
&ws
&wp
Qcr
Qvac
&wp
&ws
&ws
Qa
&wp
Qcr
&ws
2
&wp
Qa
&ws
Qvac
Qa
&ws
Qa
&wp
&wp
&wpQvac
&ws
Qa
Sandia Formation (cross-sections). Middle Pennsylvanian. On adjoining
quadrangles to the west and northwest, the Sandia Formation consists of sandstone, shale,
and pebbly sandstone, with thin interbeds of limestone and calcareous shale in some areas.
The thickness of the Sandia Formation is variable, with an average thickness of about 45 m in
the Sandia Mountains (Kelley and Northrop, 1975) and ranging up to about 90 m in the
Manzano Mountains (Myers, 1988). Pre-Sandia Formation (Mississippian (?)) sedimentary
rocks in the map area, if present, are included in the Sandia Formation in the accompanying
cross sections, with an assumed, overall thickness of the combined Sandia Formation plus
pre-Sandia strata of 45 m (~150 ft).
QvacUpland-valley alluvium and colluvium. Holocene to middle Pleistocene (?).
Predominantly silt, sand, and gravel grading into relatively coarse-grained colluvium along
valley backslopes. Along higher order drainages unit consists of eroded older deposits and
younger inset fills. Includes unmapped bedrock exposures along valley backslopes.
Thickness ranges from a few meters or less in upland valleys and over bedrock highs, to an
estimated 10 m or more along trunk drainages.
2
&wp
|Ps-
3868000
&wp
Qcr
Qcr
2
Pleistocene (?). Includes alluvial fan and coalescent alluvial fan complex, inset alluvial fills,
and colluvium on hillslopes where piedmont deposits have been incised by drainages.
Predominantly silt and sand, with coarser grained deposits dominated by sand and gravel
adjacent to bedrock uplands and along higher order drainages. Unit ranges in thickness from
a few meters or less where it forms a thin mantle over bedrock, to approximately 10 m, and
overlies older basin-fill deposits along the eastern edge of the map area.
&ws
&wp
Qa
&wp
Qp- Upper piedmont slope alluvium and colluvium, undivided. Holocene to middle
34°57'30"N
Qa
&wp
&wp Qcr
2
&wp
Qcr
Los Moyos Limestone (cross sections). Middle Pennsylvanian. On adjoining
quadrangles to the west and northwest, the Los Moyos Formation is characterized by severalmeter-thick intervals of thin- to thick-bedded limestone and thin shale and calcareous shale
interbeds, separated by one to several-meter-thick intervals containing relatively abundant,
fine-grained siliciclastic sediment. The formation also contains relatively minor sandstone
and pebbly sandstone interbeds. Limestones commonly contain abundant chert. Overall the
Los Moyos Formation contains a higher proportion of limestone relative to siliciclastic
sediments than the overlying Wild Cow Formation. Assumed to be 180 m (~600 ft) thick on
the cross sections.
Holocene
Qcr
&wp
Qcr
Qcr
&ws
&wp
Qvac
Qa
Qvac
Qa
|Pm-
3869000
Qcr
&wp
3868000
Qa
&wp
Qcr
Qcr
Qcr
&ws &ws
Qcr
&wp Qvac
1
&wp
&wp
Qcr
Qa- Valley-floor alluvium. Holocene. Predominantly silt, sand, and clay deposits of
modern drainages and associated floodplains. Coarser grained sediments are present in some
areas. Unit is inset into older deposits of units Qvac and Qp, and interfingers with younger
deposits of units Qvac and Qp along drainage foot slopes. Includes unmapped bedrock
exposures in scoured channel reaches. Unit is generally less than 3 m thick.
Late Pleistocene
&wp
Qvac
Qa
Qcr
Qcr
1
&ws
Qvac
Qa
&wp
Description of Map Units
Qa
Qa
Qcr
|Pws- Sol se Mete Member. Approximately 30 m (~100 ft) of the upper part of the
member is exposed in the map area. The upper 5 to 10 m (~15 to 30 ft) of the unit is
dominated by thick beds of ledge-forming limestone. Underlying deposits consist of
yellow, gray, and red shale with discontinuous siltstone and sandstone interbeds, and
limestone beds that range from less than one to a few meters in thickness. Limestone
beds are typically mudstones and wackestones, although brachiopods, crinoid stems,
and other bioclasts are abundant in some intervals. Laterally continuous limestone
intervals containing abundant fusulinids were not identified in the map area. Total
thickness of the Sol se Mete is assumed to be 90 m (~300 ft) thick on the cross
sections.
3870000
Qcr
2
the member is exposed in the map area, where it consists of 2 to 3 siliciclastic
intervals, several meters thick, and intervening intervals, up to a few meters in
thickness, dominated by ledge-forming limestone beds. Siliciclastic intervals are
generally poorly exposed and contain thin interbeds of tabular- and nodularweathering limestone and calcareous shale. A one- to several-meter-thick sandstone
to silty sandstone commonly crops out approximately 12m (~40 ft) above the base of
the member in the map area. Blocks of sandstone from this interval are generally red
to yellow, are composed of fine- to coarse-grained sand and pebbly sand, and are
quartzose to arkosic. Ledge-forming limestone intervals typically consist of
mudstones and wackestones, although coarse skeletal fragments are abundant in some
beds. Fusulinids are locally abundant in limestone beds in the lower part of the unit.
Total thickness of the Pine Shadow Member is approximately 60 to 90 m (200 to 300
ft) thick on adjoining quadrangles to the west and northwest.
A'
&wp
Qvac
&wp
&wp
Qcr
34°57'30"N
&wp
Qa
Qa
Qcr
Qa
&ws
&ws
Qvac
&ws
Qcr
&wp
Qvac
Qvac
Qcr
Qvac
&ws
&ws
Qcr
Qcr 1
&ws
Qcr
Qcr
Qvac
Qcr
2
2
&ws
2
&ws
Qvac
Qcr
&ws
A
Qcr
Qa
Qcr
Qvac
&ws
Qvac
&ws
Qcr
Qvac
Qvac
3871000
&ws
Qvac
Qcr
3869000
&ws
Qa
&ws
Qa
&ws
&ws
Qcr
Qcr
Qcr
&ws
Qcr
Qa
Qvac
Qvac
Qa
&ws
Qcr
&ws
1
Qcr
Qa
3
Qcr
Qcr
Qvac
&ws
2
3870000
3872000
Qa
&wp
Qcr
3871000
Qp
&ws
&ws
Qvac
Qa
Qcr
&wp
|Pwp- Pine Shadow Member. Approximately 60 m (~200 ft) of the lower part of
Unconsolidated surface deposits in the map area largely consist of upland-valley
alluvium and colluvium derived from the weathering of shale, limestone, and sandstone of
the Pennsylvanian Madera Group. Sediment transport is toward the east and the western
piedmont of the topographically closed Estancia basin. The upper piedmont slope of the
Estancia basin is present along the eastern edge of the map area. Map units consist of valleyfloor alluvium associated with modern drainages (Qa), upland-valley alluvium and colluvium
(Qvac), alluvium, colluvium, and residuum on valley backslopes and bedrock uplands (Qcr),
and piedmont alluvium and colluvium (Qp).
Unconsolidated deposits in upland valleys are generally less than 10 m thick, but
locally may be up to 20 m thick along higher order drainages. Unconsolidated deposits along
the eastern edge of the map area attain a maximum thickness of approximately 30 m, based
on well-driller’s logs for the area. These upper piedmont slope deposits include the surface
deposits shown on the map (Qp and Qa), and underlying deposits referred to here as older
basin fill. Unconsolidated sediments in the Estancia basin to the east of the map area reach a
maximum thickness of ~120 m (New Mexico State Engineer, 1967).
Radiometric ages for Quaternary map units on the Chilili quadrangle are not
available. Likewise, little is known regarding the age of the older basin-fill deposits that are
covered by the surface deposits shown on the eastern edge of the map. These older basin-fill
deposits may range in age from Pliocene to late Miocene (Smith, 1957). Geologic events
leading to topographic closure of the Estancia basin, and the timing of basin closure, are also
speculative.
Qa
&wp
&wp
3872000
General
3873000
Qvac
Qcr
&ws
Qcr
Qa
&wp
Qa
part of the Wild Cow Formation is exposed across the map area. Outcrops are largely
restricted to limestone ledges and resistant sandstone beds; exposures of fine-grained
siliciclastic intervals are generally limited to roadcuts and the walls of arroyos.
Quaternary Map Units
Qa
Qa
4
&wp
Qcr
Wild Cow Formation. Upper Pennsylvanian. Approximately 90 m (~300 ft) of the lower
35°0'0"N
Qvac
Qvac
&wp
Middle Pleistocene
Qcr
&ws
Qvac
CENOZOIC
Qcr
PALEOZOIC
Qvac
PROTEROZOIC
35°0'0"N
Late
388000
Middle
387000
Quaternary
386000
Pennsylvanian
106°15'0"W
Pwp
Pm
6000
Pwp
Pws
Ps
Pm
X
X
5000
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
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.
Pws
4000
Note: Attitude of fault surface inferred. Arrows indicate relative vertical displacement.
Ps