paleoecology,
Plio-Pleistocene
andmammalian
stratigraphy,
biochronology,
Tijeras
Arroyo,
Albuquerque
area,NewMexico
by Spencer
G. Luus,Thonas
E. Williamson,
NewMexico,
87104;
NewMexico
Museum
History,
1801Mountain
RoadN.W.,Albuquerque,
of Natural
andJaySobus,
20742-7531
College
ol Human
Ecology,
2100MarieMountHall,University
Park,Maryland
ol Maryland,
College
Abstract
Strata assignedto the SierraLadrones
Formation of the SantaFe Group in Tijeras Arroyo near the Albuquerque International Airport are more than 75 m
thick and consistof sandstones,pumiceous sandstones,gravels, and minor
claystones.Thesearedepositsof a mainstem (axial)Rio Grande that intertongue
eastward with alluvial-fan faciesderived
from the Sandia and Manzanita uplifts.
Fossil mammals from the Sierri Ladrones Formation in Tiieras Arrovo indicate it is of Plio-Pleistocene(BlancanIrvingtonian)age.Blancanmammalsare
HypolaguscI. H. gidleyi and Equuscumminsii; lrvingtonian mammals are GIyptotheriumcf. G. arimme, Equuscf. E sotti,
cf. Camelopssp., Mammuthusmeridionalis. and M imperator.Fossils of these
taxa, their taphonomy, and the enclosing sedimentssuggestthat during the
early Pleistocenethe TijerasArroyo area
was a semiarid piedmont plain with a
nearby flora dominated by open grassland or short-grassprairie.
FIGURE 1-Albuquerque Basin with distribution (after Tedford, 1982) of Santa Fe Group
strata(shaded)and key sectionsmentionedin
the text: 1, type Ceja Formation; 2, section in
Tijeras Arroyo (Figs. 2, 3); 3, type Cochiti Formatron.
Alsoin thisissue
area in Fig. 2
Laramidestratigrapy
of the
LittleHatchetMountains
Galleryof Geology-Killion
Canyon
names
Geographic
1992MineralSymposium
abstracts
1993NMGSFallField
Conference
Service/News
Upcomingmeetings
1994NMGSFallField
Conference
Staffnotes
p. 9
p.16
p. 17
p.18
p.20
p.21
p.22
p.22
p.23
Introduction
1978). Subsequentmapping by Kelley
(1977)reflected Lamberfs extension of the
Although Pleistocene mammals were
upper buff member to east of the Rio
first reported from the Albuquerque area
Grande. However, Kelley (1977) coined
(Fig. 1) by Herrick and fohnson (1900,p.
and applied the name CejaMember of the
224), no serious effort has been underSanta Fe Formation to these rocks, intaken to document these fossils until retending it to replaceBryan and McCann's
cently. This documentation (O'Neill and
Rrgby,1982;Lucasand Logan, 1984;Lucas, (1937)informal term "upper buff."
Kelley's (1977)type section of the Ceja
1987; Lucas et al., 1988)has focused on
t h e l a t e P l e i s t o c e n e( R a n c h o l a b r e a n ) Member of the SantaFe "Formation" (Fig.
1) is along the Ceja del Rio Puerco (sec.
mammals collected ftom gravel pits de19 T10N R1E) and representsthe upper
veloped in relatively young terrace depart of the section that Bryan and Mcposits inset into the Rio Grande valley, the
Cann (1937)originally designated '/upper
Edith Formationof Lambert (1968).Fossil
buff". Lambert (1968) had already demammalsfrom the Edith Formationwithin
the Albuquerque city limits are Glosso- scribed a reference section of his "Upper
Buff" formation at the same site, but he
theriumharlani,Equuscf. E. occidentalis,
Bison sp., Camelops
hesternusandMammuthus included "middle" Santa Fe beds underlying Kelley's Ceja Member in this forcolumbi,a typical assemblageof large Ranmation, as had been previously done by
cholabrean (Wisconsin-age)mammals.
Wright (1946;seealso Lambert, t978, p.
Older Quaternary and latest Pliocene
151). Unfortunately, no detailed mapmammals, however, are alsciknown from
ping, or tracing of key beds, has ever been
within the Albuquerquecity limits. These
done between the type Ceja locality and
l o w - d i v e r s i t v f a u n a s , o f B l a n c a na n d
the JemezValley (Rinconesde Zia,35km
Irvingtonian age, were first discoveredby
to the north) where Bryan and McCann
Lambert (1968)and subsequentlydeveloriginally defined theii lower gray-midoped by T. R. Logan (1984;Logan et al.,
dle red-upper buff stratigraphic sequence
1984)and us during the mid-1980's.Here,
as the referencesection for their SantaFe
we describethesefossilsthat spanthe PlioFormation in the northern Albuquerque
Pleistoceneboundary and interpret their
Basin.
biochronological significance. In this arManley (1978)and Tedford (1982)have
ticle, NMMNH refers to the New Mexico
suggestedthat the Ceja Member and the
Museum of Natural History, Albuquerque
more broadly defined "upper buff" memand UNM to the Universitv of New Mexber (formation) interfinger to the north
ico, Albuquerque.
with volcaniclastic sandstone and conglomeratethatBailey et al. (1969)and Smith
Stratigraphy
et al. (1970)termed the Cochiti Formation
Upper Cenozoic deposits of the Rio
of their KeresGroup (seealso discussion
Grande rift, from Colorado to Texas,have
by Hawley and Galusha, 1978).However,
generally been referred to as the SantaFe
the latter unit has never been well defined
Glg.rp (Hawley, 1978; Lucas and Ingerin its JemezMountains type area, and resoll, 1981).However, in the Albuquerque
cent dating of associatedKeresGroup volBasin, the term Santa Fe Formation, lncanics by Gardner et al. (1985)brackets
troducedhereby Bryanand McCann (1937,
the age of the type Cochiti between 13.5
1938), has long been used. Bryan and
and 5.5 million years (mid- to late MioMcCann (1937,L938)divided the SantaFe
cene).
Formation in the Albuquerque Basin into
CejaMember (upper "upperbuff") strata
three informal members:lower gray, midalong the Ceja del Rio Puerco correlate
dle red, and upper buff. The lower gray
with at least the middle part of the Sierra
and middle red members are now iubLadrones Formation (Machette L978a,b;
sumed in the Zia Formation of Miocene
Hawley, L978, chart 1), which has a type
(late Arikareean-Clarendonian) age (Galarea at the southern end of the Albuusha, L966;Gawne, 1981;Tedford, l91l,
querque Basin near San Acacia. A Sierra
re82).
Ladrones Formation referencesectionhas
/'upper
The overlying
buff member" of
recently been described in the lower Rio
the Santa Fe Formation was originally
Puerco valley (Gabaldonbadland area)by
conceivedby Bryan and McCann-(lg3i,
Lozinsky and Tedford (1991).At ttraf lopp. 815-816) for buff-colored, generally
cality the formation is underlain by "midcoarse-grained
("fan deposits")stratathat
dle" SantaFe Group bedsof Hemphlllian
are at the top of the Santa Fe Formation
(lateMiocene)ageiorrelated withihe upalong the Ceja del Rio Puerco west of Alper Popotosa Formation of Denny (1940)
buquerque (Fig. 1). Lambert (1968)used
and Machette (1978a).Machette's type Sithe term //upper buff formation" to refer
erra Ladrones comprises ancestral Rio
to Bryan and McCann'sunit and also exGrande and intertonguing piedmont altended to it into the (current) Albuquerluvial deposits. It overlies the Popotosa
que city limits by identifying it eastof the
west of San Acacia and south of the LadRio Grande in the walls of Tiieras Arroyo
ron Mountains. Basalt flows interbedded
(secs.1 and 12 T9N R3E)and in the scarp
with the lower SierraLadronesFormation
southwest of the Albuquerque Internain the San Acacia and Socorro area have
tional Airport (Fig. 1; see also Lambert,
K-Ar ages of 4 to 4.5 million years, and a
February 1993 New Mexico Geology
sparseBlancan vertebrate fauna has been
describedin the formation (asmapped by
Machette, 1978b)in the Ceja del Rio Puerco
escarpmentabout 10km south of the type
Ceja Member section (Tedford, 1981).The
Sierra Ladrones depositional environment in the Albuquerque Basin has recently been described by Lozinsky et al.
(1ee1).
TABLE l-Stratigraphic section of the Sierra
Ladrones Formations exposedin Tijeras Arroyo,
NE1/+sec. 17 and NW1L sec. 16 T9N R3E, Bernalillo County, New Mexico.
Unit
Lithology
Thickness
(m)
Sierral-adronesFormation:
10. Sandstone, noncalcareous,
very Iight gray (N8) and light
bluish-gray (58 7/L); medium-to very coarsegrained
in two populations: medium- to coarse-grained
(2.0-0.0 {) subrounded to
angular quartz grains and
coarse- to very coarse
grained (> 1 0); rounded
pumice grains; trough
crossbedded;top of unit is
airport surface.
1.2.0+
New AAexnc@
GEOLOGY
. Science
andService
tssN
Volume
0196-948X
15, No. 1, February
1993
Editor: Carcl A. I{jellming
Published
quarterlyby
New Mexico Bureau of Mines and
Mineral Resources
a division of New Mexico lnstitute of
Mining & Tchnology
BOARD OF REGENTS
Ex-Officio
Bruce King, Gomor of Nru Muim
Alan Morgan, Superintendeil ol Public In;ttuction
APPointed
Lt. Gen. Leo Marqtez, Pres.,1989-796, Albu4uoque
Charfes Zmmerly, Se.lTreas.,1997-7997,Sxorro
Diane D. Denish, 1992-1997,Albuquerque
J. Michael Kelly, L992-I997,Rrewll
Steve Tores, 7997-797, Albuqwque
New Mexico Institute of Mining & Tehnology
Prqidnt..
... LaurenceH.Lattman
New Mexico Bureau of Mines & Mineral Rercurces
Dir@torond StateGNWist . . . Charles E. Chapin
Subwi/iore: Issued qurterlt FebMry, May, AugusL
November; subscription price $6.00/calendaryear.
Editorial mattq: Articles submitted for Dubliation
should be in the editor's hands a minimum of five
(5) months before date of publication (Februry
May, Autust, or November) and should be no longer
than 20 typwitten,
double-spacedpages. All
scientific papers will be reviewed by at least two
people in the apprcpriate field of study. Address
inquirie to Carol A. Hielming, Editor of Nm Meim
Ceology,New Mexico Bureau of Mines & Minenl
Resources,Sorcro, NM 87W4n6Publishedas publk dowin, thercforereprdrcibk without
Wrmission. Sourcecredit requested.
Circulation:1,ffi
P/irra: University of New Mexico Printing Sewices
Unit
9.
,7
6.
3
2.
1.
Lithology
Thickness
(m)
Sandstone, noncalcareous,
grayish-orange (10YR 7/4),
fine- to coarse-grained
(0.503.0 Q); subangular quartz
and chert; trough crossbedded.
Sandstone, slightly calcareous, grayish-orange (10YR
714),ftne- to coarse-grained
( 3 . 0 0 - 0 . 0Q ) ; s u b a n g u l a r
quartz and chert; bed has
prominent reddish-brown
color at a distance, with
gravels in the upper 257o;
trough crossbedded.
Sandstone, noncalcareous,
pale yellow-brown (10YR6/
2); in two populations: very
fine to medium-grained
(1.50-3.5 $) quartz and
quartzite, and quartz gravel
up to 5 cm diameter; poorly
sorted and very conglomeratic, with pumice in upper
bed; trough crossbedded.
Sandy clay and sand, calcareous,grayish orange-pink
(5YR 7/2) and pinkish-gray
(SYR 8/1); in three populations: fine- to coarse-grained
( 2 . 5 0 - 0 . 0S ) , s u b a n g u l a r
quartz grains, clayballs in
sandstone, and pumice balls
(up to 1.5 cm diameter).
Sandstone, slightly calcareous, yellowish-gray (5Y 8/1),
fine- to medium-grained
(2.00-0.00); poorly sorted
subrounded quartz; trough
crossbedded.
Claystone, noncalcareous,
grayish-green (10 GY 5/2).
Sandstoneand gravel, noncalcareous,pale yellowishbrown (10YR 6/2); in three
populations: very fine- to
medium-grained (1.50-3.5
$) poorly sorted quartz and
quartzite grains with pumice, quartz gravel (up to 5
cm diameter), and conglomerates(up to 15cm diameter); trough crossbedded.
Sandstone, noncalcareous,
yellowish-gray (5Y 8/1);medium-grained (2.5-1.5 0)
quartz and chert; moderately sorted, frosted, subangular to subroundedgrains;
high-angle crossbedsand
convolute bedding.
Sand, noncalcareous,yellowish-gray (5Y 8/1),fine- to
medium-grained(2.5-1.5{);
quartz, poorly sorted subrounded grains; sandstone
interbedded with laminar to
massive green clay partings, one clay band 20 cm
thick; fragmentary bone
present; much slope debris.
Covered.
total
6.7
i + s 6 ,t q s z
i + s s ,t + s l
( T 9 N .R 3 E )
10.1
T^8-l(m-
Santa Fe
Group outcroPs
-
72.2
NMMNH fossil
localities
1455 MammuthusimPerator
Elephantidae
S I E R R AL A D R O N E S
FORMATION
3.4
1453, 1454, 1456' 1457
+1452,
Mam mut hus merid ionalis
Gtyfrotheilum cl. G' ailzonae
cf. CameropssP. Equidae
6.1
7.2
Equus cf. E. scotfi
1tl
t
conglomerate
s a n csl t o n e
s i l t s to n e
1459 Equus cf. E. scotti
m u ds t o n e
t3.7
|
3.4
, '",",.
lowest oumice clasts
+
1458
Equus cl. E. cumminsii
Hypolagus cf . H. gidleyi
8.1
?63
FIGURE 2-Measured stratigraphic section in Tijeras Arroyo with inset map showing fossil localities mentioned in text. S6efable 1 for description of lithologic units in measured section'
New Mexico Geology February 1993
The type Ceja Member, as defined by
Kelley (1977) and described by Lambert
(L978), is a fluvial unit dominated by
channel sandsand gravels.It was deposited by major tributaries to the ancestral
Rio Grande that headed in the southeastern Colorado Plateauand San PedroNacimiento Mountain region northwest
of the Albuquerque Basin. In contrast, the
upper SantaFe beds exposedin the lower
Tijeras Arroyo areaeast of the Rio Grande
(discussed in this paper) are deposits of
a main-stem (axial) Rio Grande that intertongue eastward with alluvial-fan facies
derived from the Sandia and Manzanita
uplifts. This ancestral fluvial system followed a course west of the bise of the
Sandia-Manzanita piedmont slope that
was very closeto the modern incised river
valley in the Albuquerque metropolitan
area.Upper SantaFe beds eastof the Rio
Grande were also assigned to the Ceja
Member by Kelley (1977) and tentatively
correlatedwith the upper buff by Lambert
(1968).However, at least the upper part
of these deposits are of late Pliocene to
early Pleistoceneagebecausethey contain
pumice clastsderived from the 1.6 to 1.1
Ma eruptions of the Toledo Valle Grande
calderacomplex (BandelierTuff). As demonstratedhere, uppermost SantaFe Group
strata in the lower TijerasArroyo areaalso
contain a mammalian fauna of late Blancan and Irvingtonian age (seealso Logan,
1984).We, therefore,proposethat the term
Ceja Member be restricted, at least at
present, to upper Santa Fe Group beds
(Sierra Ladrones Formation) exposed in
the Puerco Valley area of the western Albuquerque Basin. Uppermost Santa Fe
Group depositsin the lower TijerasArroyo
area here are designatedas part of an unnamed upper member of the Sierra Ladrones Formation that is dominated by
channel deposits of the ancestral Rio
Grande.
This unit is 64.8m thick in TijerasArroyo
and is dominated by sandstone(76Vo-of
FIGURE3-Some outcrops in TijerasArroyo: A, SierraLadronesFormation crossbeddedsandstone
the measuredsection)and lesseramounts
(Fig. 2, unit 2); B, gravelly sandstones,siltstones, and sandstonesof Sierra Ladrones Formation
of gravel (18%) and claystone/siltstone (Fig. 2, units 5-7).
(6%). Particularlydistinctive is the dominanceof pumice, in sizesfrom sandgrains
as well as the relatively limited outcrop
unit. We provisionally endorse this conto cobbles.The pumiceous strataat Tijeras
distribution of the pumice-bearingIrvingclusion by terming all these strata Sierra
Arroyo presenta striking contrastto untonian strata supports the idea that these
Ladrones Formation, in part becausethis
derlying strata that lack pumice (Table 1;
strata are inset into older, Ceia Formation
decision is a conservative one that introFigs. 2, 3). However, we nonethelessalso
strata. Furthermore, as Cather (written
duces no new nomenclature. New stratassign these underlying strata to the Sic9mm. t992) notes, this inset explains both
igraphic nomenclature ma, however, be
erra Ladrones Formation based on their
the lower elevation of the Llano de Mannecessary if further study demonstrates
lithology and stratigraphic position. Alzano surface relative to the Llano de Althat the pumice-bearing Irvingtonian shata
though we assign the pumice-bearing Irbuquerque (cf. Kelley, 1977; Machette,
exposed at Tijeras Arroyo are a distinct
vingtonian strata at Tijeras Arroyo tothe
1978c)as well as the apparent lack of Irunit inset into older strata.
Sierra Ladrones Formation, we note that
vingtonian strata west of the Rio Grande.
not only are they younger than the Sierra
However, |. Hawley (oral comm. 1992)
Vertebrate paleontology
Ladrones, which near Socorrois about 5Fossil mammals occur in two intervals
in Tijeras Arroyo (Fig. 2) and are described below.
Lq
pumice first appears on outcrop. He thus
suggeststhat all strata exposed at Tijeras
Arroyo are part of a single stratigraphic
February 1993 Nat Mexim Geology
Glyptotheriumcf. G. arizonae
NMMNH P-12876from locality l4sa (Fig.
4H-I) is a caudal scute resembling the
FIGURE 4-Mammalian fossils from Tijeras Arroyo: A, Equuscumminsii(NMMNH P-12895),ventral view of palate; B, Equuscumminsii(NMMNH P12895),right P-M3; C, Equuscf . E. scotti(NMMNH P-12884),leftupper cheek tooth; D, Equuscf . E. scotti(NMMNH P-72891),right dP:?; E, Equidae
(NMMNH P-128S3),right M.; F, Equidae (NMMNH P-12885),second phalanx in plantar view; G, cf . Camelops
sp. (NMMNH-PI2887), proximal.end
of left astragalusin doisal view; H-1, Glyptotheriumcf. G. arizonaeNMMNH P-I2876)tail scute in lateral view (H) and dorsal view (I); l-K, Hypokgus
cf. H. gidleyi (NMMNH P-I2938), P. (right is mesial, top is labial); L, Hypolaguscf . H. gidley (NMMNH P-12938),left dentary fragment with P2 in
lingual view; M, Mammuthusmeridionalii(UNM 11028),mandible with right ind left M.. Bar scalesare 1 cm except for A (2 cm), K-L (2.5 mm) and
M (10 cm).
Neu Mexico Geology February 1992
raised, convex distal scutesillustratedby
Gillette and Ray (1981,fig. 93),which Logan (1984)attributed to Glyptotheriumcf.
G. arizonae.This is the first teport oI Glyptotheriumin New Mexico. 'A glyptodont"
was previously reported from the Camp
RiceFormation(a unit correlative,at least
in part, to the SierraLadronesFormation)
in the Mesilla Basin of southern New
Mexico (Tedford, 1981.,p.1019). At 35'N
latitude, the Tijeras Arroyo Glyptotherium
is almost the northernmost ociurrence of
lhe genus (cf. Gillette and Ray, 1981,figs.
2-4). A slightly more northerly occurrenceis representedby five scutesof GIyptotherium tUUVtNlt p -tgZgl collectedtv
Wesley Peters at NMMNH locality 154i6
in a gravelpit in the NEr/oNEr/oSW/c
sec.
27 T13N R4E,north ofAlbuquerque near
Algodones(Fig. 1). This locality also is in
the SierraLadronesFormation.
Hypolaguscf. H. gidleyi
NMMNH P-12938(Fig. af-L) from locality 1458consistsof a right dentary fragment with the root of I, and a very worn
Pr, a left distal tibia, a metacarpil, and
two phalanges.Tedford (1981)identified
this specimenasHypolngus
sp. White (1987,
p. 438)_described
this specimenas HypoIaguscf . H. ringoldensrs.He also statdd it
was "possibly from the Chamita formation," a unit of MiePliocene (Clarendonian-Hemphillian) age restricted to the
Espaflola Basin of north-central New
Mexico (MacFadden, 1977). This cannot
be correctbecausethis unit is not present
in the Albuquerque Basin (T€dford, 1981).
We assign NMMNH P-12938to Hr1polagus cf. H. gidleyi for the following reasons: 1) I-P, diastemalength (15.imm)
1lq P, anteroposteriorlength (3.5 mm)
fall within the range of vaiiation for H.
gidleyi (but outside that of H. ringoldensis:
White, 1987,fig.9); 2) the P, lacls an anterior r_eentrant(Fig. 4f-K), which is part
of the diagnosis of H. gidleyi(White, 1987,
p. a3Q; and 3) the posteroexternalreentrant on P. is deflectedposteriorly, a characteristicnot typical of H. ringolderzsrs
but
of variation'o f H. gidleyi
ryilhi" the ran-g-e
(White, 1987,fig.7).
Equuscf. E. cuminsii
NMMNH P-12895from localiry1458(Fie.
4A-B) includesa damagedpalaiecontaiiing left P2-M3and riglit p.-Mr, the maxi l l a r y s y m p h y s i s ,a t l a s , a x i s a n d t w o
cervical vertebrae, incomplete right humerus/ distal tibia, and cranial fragments.
This specimen is referred to Equis cf. E.
cumminsiion the basis of occlusalmorphology (note the absenceof enamelcrenulations and absence of a hypoconal
groove:Osborn, 1,91,8,
p.270, pi.24; Cidley, 1901,p.127, fig.17). This issignment
remains tentative, however, becausethe
type specimen of E. cumminsiiCope consistsof two isolatedupper molariforrnteeth
and the speciesmay, strictly speaking,be
February 1993 New Mexico Geology
TABLE 2-Dimensions of Equusteeth (in mm)
from the Sierra Ladrones Formation at Tiieras
Arroyo.r, length measuredlabially;r, maimum
width from protocone to mesostyle.
mesiodistal lingual-labial
lensthr
width'z
NMMNH P-T2895
left P2
left P3
left P4
left Mt
left M2
left M3
NMMNH P-1289L
right dP3?
right dPa?
NMMNH P-I2940
Ieft upper
molariform
NMMNH P-1294I
left upper
molariform
NMMNH P.72884
left upper
molariform
NMMNH P-12883
right M3
NMMNH P-T2936
right lower
molariform
40.5
26.7
24.3
29.3
28.0
30.6
24.0
34.2
27.9
27.0
28.6
19.6
34.4
35.2
77.7
73.6
31.8
32.2
35.0
33.6
33.1
28.2
42.0
16.6
(36.0)
77.4
a nomendubium.Tedford(1981)identified
this specimen as Equussimplicidens,but It
is too small to pertain to that species.E.
cumminsiiis a Blancan horse (Kurten and
Anderson, 1.980).
Equuscf. E. scotti
NMMNH P-12891.from locality L459is
a damaged right dentary with itP3 (Fig.
4D) and dPa, and the unerupted fragments of P, and M,. Theseteeth are in the
size range of E. scotti and E. giganteus.
NMMNH l-12940, P-12941,and P-12884
are left upper molariform teeth from locality 1454,P-12940and P-12884being relatively unworn (Fig. aC). NMMNH P12937ftom locality 1457 is a fragmented
lower molariform (Pr?) toofh, and
NMMNH'J.2936isa lower deciduousmoIariform tooth from localitv 1457. These
teeth are assigned to Equus'cf.E. scottion
the basis of size (Table2).
Equidae
NMMNH P-12883from locality 1454is
a right M, (Fig. 4E) referred to Equuson
the basisof occlusalmorphology.NMMNH
P-12878from locality L454is a distal tibia,
a proximal humerus and additional bone
fragments. The transverselength and
matmum oblique articular length of the
distal tibia fall in the size range of E. niobrarensisand are intermediate between E.
conaersidensand E. niobrarensis,respectively (Harris and Porter, 1980).NMMNH
P-12881from locality 1454is a partial maxillary symphysiscontainingthe alveoli of
Ir-I3-and fiaghentary rootiof the canines
(length : 16.7mm, width : 13.7mm).
NMMNH P-12885from locality 1454is a
Iargefirst phalanx; the overall dimensions
of length, width of proximal surface,depth
of proximal surface, and width of distal
surfacefall into the upper size range of E.
scoffi(Akersten, 1972,table 14;Harris and
Porter, 1980, table 1). NMMNH P-12890
from locality 1454is a left navicular (anteroposteriorlength: 47.6mm, width :
60.7 mm). NMMNH P-L2892from locality
1t145is a right innominate with ischium,
pubis, and partial ilium (maximum preserved length : 4L0 mm, maximum acetabular length : 68.9mm). NMMNH P12939is a metacarpal from locality 1454.
Overall size and comparison with Harris
and Porter's (1980,p. 59, fig.7) scatter
plot of proximal and midshaftwidths suggest a small specimenof E. conaersidens
or
a horse of similar size.
cf. Camelopssp.
NMMNH P-12887from locality 1a56(Fig.
4G) is a right proximal astragalus. Morphology (note the wide valley and convexity of the proximal trochlea and also
the high nanow lateral condyle) excludes
the Llamini but typifies the Camelini
(Webb, 1965,p.29). This specimenis referred tentatively to Camelops
on the basis
of its resemblanceto the astragalusof C.
hesternusillustrated by Webb (1965, pp.
29,31, frg. U).
Mammuthusmeridionalis
NMMNH P-12894from locality 1452is
an incomplete mandible (Fig. 4M) with
left and right M, (Fig. 5A). Although the
mandibular symphysis is incomplete anteriorly, the spout was relatively short and
not significantly flexed ventrally. The horizontal rami are relatively long, low, and
narrow. What is present of the ascending
rarni suggeststhey were relatively low and
inclined posteriorly.
The right M. is better preserved and
more complete.Both Mrs are heavily wom
and relatively long (282* mm). On the
right Mr, six plates are preserved, but the
position of the anterior alveoli and length
of the anterior worn dentine suggest at
least two additional plates were present.
Plate enamel is extremely thick (average
enamel thickness : 38 mm), and the plate
ratio (4.0) is very low. Becauseof extreme
wear, it is impossible to estimate accurately crown height, but it appearsto have
been low. These features indicate that
NMMNH P-12894 is a very primitive
Mammuthusassignableto M. meridionalis
(Lucas and Effinger, 1991).
Mammuthusimperator
NMMNH P-12888(Fig. sB-C) from locality 1455is a left M3 in a maxillary fragment. This tooth has 20+ plates, enamel
of moderate thickness (3.0 mm), and a
plate ratio of 6. It is 330+ mm long, 190
mm high, and 103 mm wide. All metrics
FICURE S-Mammoth molars from Tiieras
Arrovo: A, Mammuthusmeridionalis(UNM
1102d),occlusalview of right Mr; Id-;C,Mammuthus imperator(NMMNH P-12888),occlusal
view (B) and lateral view (C).
thus place it comfortably within the range
of Mammuthusimperator(Madden, 1981;
Lucas and Effinger, L991).
Mammuthussp.
NMMNH P-12893 from locality 1453
consists of right and left ilia, incomplete
pubic bones, and the right acetabulum.
The ilia are very wide and flaring, and the
innominate is otherwise typical of the Elephantidae. Given the relatively large size
of the acetabulum (see Olsen, t979), rhis
pelvis is assigned to Mammuthussp.
Taphonomy and paleoecology
We present here a few taphonomic and
paleoecological inferences for the Sierra
Ladrones Formation in Tijeras Arroyo
based principally on localities 1452,1453,
and 1454. The immediate context of the
Mammuthuspelvis (locality 1453)was excavated in a controlled manner, so reconstruction of the local sedimentary context
was possible. In general, the section is
underlain by a clast-supportedbed of
gravel- to cobble-sizedrocks of undetermined lateral extent. Above this level lie
alternating gravel lenses and sand units
of varying coarseness,with fine-grained
sands typically interbedded with gravel
lenses (Fig. 64). Clay bodies (0.5-1.5 m
diameter) are present, and medium- to
coarse-grainedsands often contain tuffaceouspebbles.Gravel lensesin mediumto fine-grained sand units have the appearanceof inverted channels(convex on
their upper surfaces),although these do
not form continuous structures. Someindication of normal grading is evident, but
there is no evidence of consistent clast
orientation or imbrication.
The pubic symphysis of the mammoth
pelvis was intact during deposition becauseboth innominates were in anatomical position. The pelvis was oriented
N45'W (bearing through the pubic symphysis and the articular surfaces of the
ilia) with a dip of 20'along magneticN25'E.
This orientation is consistent with a
southward-flowing current, with the long
axis of the pelvis parallel to flow.
The sedimentary context of the Mamconsistsof
muthusmandible (locality 1.452)
a upward-fining sequence of clast-supported gravels overlain by poorly sorted
quartz sandsand 15cm of eolian soil. Clay
bodies formed a nearly continuous surface on which the mandible lay; such a
FIGURE 6-Mammuthus mandible in situ at locabty 1452(note cobble embedded in right ramus and the scouredand weathered condition
of the bone).
New Mexico Geology February 1993
surface may represent cut-bank failure or
accretion on a longifudinal channel bar.
The sequenceis cappedby about 2 cm oI
fine-grainedsandsand pebbly lag
-ofdepos!t9, Th9 mandible lay at an angle about
20' at the foot of a clay bar running southeast-northwest, bearing N50"E. A subsptrerical clay body apparently fixed the
lett ramus to the clay surface, and the
eroded surfaceof the 6one indicatesa period of in-place scouring prior to buiial
(Fig. 68).
Localities L452 and 1.453resemble the
characteristic lithofacies of low-sinuositv
fluvial systems (see, for example, Wiiliams and Rust, 1977).Bar migration and
channel shifts produce an alternating sedimentary morphology that is clearly present at both Mammuflrzs sites. Inverted
gravel lenses (transverse sections of longitudinal point bars), rolled subspherical
clay bodies, and other large traniported
clasts, together with larger clay massesof
accretionary origin, all point to a low-sinuosity, high-energy (braided) fluvial environment with frequent channel shifts and
intermittent subaerial exposure. This is
characteristic of the present-day Rio
Grande system.
The preservation and condition of the
fossils support such an interpretation.
These sites appear to have been winnowed of all but large, traction-transported elements corresponding to
transport groups two and three (Voorhies, 1969). Both Mammufhusspecimens
indicate some degree of predepositional
attrition and transport.The mandibledisplays extensive stress-line weathering
along the lateralaspectsof the right and
left horizontal rami-andexfoliatio-nof superficial laminae on the lateral surface of
the- right ramus comparable to stages 3
and 4 of Behrensmeye{s (L978) wiathering scale,This indicatesperhaps as long
as a year of subaerialexposurebefore buiial, depending on local climatic conditions. The accumulationof cobblesaround
the jaw (inctuding a 1,0-cmcobble lodged
between the molar and ramus), as well as
extensivesuperficial pitting and scouring,
suggest in situ abrasion by transported
particles. Finally, the articulated condition of both pubic and mandibular symphyses suggeststhat burial was rapid. The
transport-resistant nature of both Mammuthus specimens, their weathered condition, and the absenceof associated
skeletalelementsdespiteevidenceof rapid
burial all imply high-energy deposition.
This contrasts with the lithology of the
fossil-bearingmud unit (locality 1254)that
yielded Glyptotheriumand Equus.The
massive clay unit suggests the presence
of an abandoned channel, and perhaps
local sediment stabilizationby vegltation.
The fragmentary nature of teeth and bones
appears to be due to recent weathering
rather than to the original depositional
environment.
The sands and gravels of the Sierra La-
February 1993 New Mexico Geology
drones Formation at Tiieras Arroyo thus
were deposited on an-arid or semiarid
piedmont plain via a systemof shifting or
ephemeralstreams(Lambert, 1968).The
stratigraphy of the region shows an alternating pattern of matrix-supported
gravel clastswith interbedded fine-grained
intervals,indicatingalternatinghigh- and
low-energy systems with frequent upward-fining depositionalepisodes.On the
whole, coarser materials become more
common as one proceedsup the section,
which may indicate a gradual transition
from more distal to more proximal fluvial
deposition over the region. On a smaller
scale, localities 1/52 and 1453clearlv indicate the high-energy regime and'dissectedtopography of a low sinuosityriver,
both in nature of the local sedimentology
and in fossil assemblages,
which are deficientin small,low derisityelementswith
low cross-sectionalareas. Locality 1.454
appears to represent a local, lower energy
variant of such a depositional environment.
, We can only make the most generalpaleoenvironmental inferencesbasedon the
vertebrate fossils becausethev are so few
and scattered. The o..rrr."rr." of large
grazing mammals such as EquusandCamelops suggestsa nearby flora dominated
by open grassland or short-grassprairie.
Mammuthuswas presumably both a grazing and browsing mammal and therefore
indicates either kind of vegetation or a
grassland-woodland mosaic.
Biochronology
The fossil mammalsfrom TilerasArroyo
indicate that the strataexposedthere are
of Blancanand Irvingtonian age.Two taxa,
Hypolagus cf. H. gidleyi and Equus cumminsii, are found in the lowermost exposures of the Sierra Ladrones Formation.
H. gidleyi is known primarily from Blancan faunas,although some specimensmay
be as old as Barstovian(White, 7987).E.
cumminsiiis a typically Blancanspeciesbut
is not known from earliest Blantan localities (Kurten and Anderson, 1980).This
fossiliferouslevel of the Sierra Ladrones
Formation is thus broadly correlativewith
other Blancanfaunasin the SantaFe Group
(e.9., Lucasand Oakes,1986),but a more
precisecorrelationis not possible.
The fossiliferous interval at Tiieras
Arroyo in the middle-upper exposuiesof
the Sierra Ladrones Formation contains
Mammuthusas its most common element.
The presenceof mammoth is taken by us
as incontrovertible evidenceof its postBlancan age. Other mammals present,
Equus cf. E. scotti,cf. Camelops
sp., and
Iyptotheriumcf. G. arizonae,suggest an
Irvingtonian age. This age is consistent
with abundant reworked Guaie Pumice
present in the SierraLadronesFormation
at TijerasArroyo (Lambert, 1968),which
indicates these strata are no older than
about 1.51Ma (unpubl. QArfeAr date:W.
Mclntosh and S. Cather, pers. comm.
1992).The section at Tijeras
Arroyo thus
-(Pliocene)-and
producesboth Blancan
Irvingtonian (Pleistocene)mammals. However, it clearly is not a continuous record
of the Blancan-Irvingtonian transition. It
does, nevertheless,provide one of the few
documented faunas of Irvingtonian mammals from New Mexico, which includes
one of the northernmost occurrencesof
glyptodonts as well as a very primitive
Mammuthus.
AcrNowr-sDcr'cvrs-This research was
supported in part by the Societyof Sigma
XI. We thank Thomas R. Logan for his
invaluable assistanceduring the early
phase of this research.Critical comments
on this manuscriptby S. M. Cather,J. W.
Hawley, R. P. Lozinsky and R. H. Tedford
improved its contentand clarity. S. Cather
and W Mclntosh shared both their expertise in the field and unpublished radiometric ages,for which we are grateful.
References
Akersten, W. A.,1972, Redlight local fauna (Blancan)
of the Love Formation, southeastern Hudspeth
County, Texas:Bulletinof the TexasMemorialMuseum, v. 20, pp. 1.-53.
Bailey,R. A., Smith, R. L., and Ross, C. 5., 1969,
Stratigraphic nomenclatureof volcanic rocks in the
Jemez Mountains, New Mexico: U. S. Geological
Survey, Bulletin 7274-P,79 pp.
Behrensmeyer,A. K., 7978,Taphonomicand ecologic
infomation from bone weathering: Paleobiology,
u. 4, pp.750-162.
Bryan, K., and McCann,F.T.,7937,The Ceiadel Rio
Puerco: a border feature of the Basin and Range
province in New Mexico. I. Stratigraphy and structure: Journal of Geology, v. 45, pp.801-828.
Bryan, K., and Mdann, F. T., 7938,The Ceia del Rio
Puerco: a border feature of the Basin and Range
province in New Mexico, II. Geomorphology:Journal of Geology, v.46, pp. l-76.
Denny, C. S., 9n, Tertiary geologyof the San Acacia
area, New Mexico: Journal of Geology,v. 48, no. 1,
pp.73-706.
Galusha,T.,7966,The Zia Sand Formation, new early
to medial Miocene beds in New Mexico: American
Museum Novitates, no. 2277, pp. 7-72.
Gardner,J. N., Gotr, F., Garcia,S. R., and Hagan,
R. C., 1985, Stratigraphic relations and lithologic
variations in the Jemezvolcanic field, New Mexico:
Journaf of GeophysicalResearch,v.91,, no.B.2, pp.
7763-1n8.
Gawne, C. E., 1981,,Sedimentologyand stratigraphy
of the Miocene Zia Sandof New Mexico:Geological
Societyof America, Bulletin, v.92, pp.999-7007.
Gidley, J. W., 1,901,Tooth charactersand revision of
the North American speciesof the genus E4aas:
Bulletin of the American Museum of Natural History, v.'1.4, pp. 91-142.
Cillette, D. D., and Ray,C. E., 1981,Glyptodontsof
North America: Smithsonian Contributions to Paleobiology no.40, Washington, D. C., Smithsonian
Institution Press,255 pp.
Hanis, A. H., and Porter,L. S. W., 1980,Late Pleistocene horses of Dry Cave, Eddy County, New
Mexico: Journal of Mammalogy, v.61,, pp. 46-65.
Hawley, J. W. (compiler), 1978,Guidebook to the Rio
Grande rift in New Mexico and Colorado: New
Mexico Bureau of Mines and Mineral Resources,
Circular 153, 241 pp.
Hawley, J. W., and Galusha, T., 1978, Bernalillo to
south of San Ysidro: New Mexico Bureau of Mines
and Mineral Resources,Circular 153, pp.777-1,83.
Henick, C. L., andJohnson,D. W.,1900,Thegeology
of the Albuquerque sheet:Denison University, Science LaboratoriesBulletin, v.'1,1,,pp. 175)39.
Kelley, V. C.,1977, Geology of Albuquerque Basin,
New Mexico: New Mexico Bureau of Mines and
Mineral Resources,Memoir 33, 60 pp.
(Continues on p. 151
Gillette, D. D., Wolberg, D. L., and Hunt, A. P., 1986,
Tyrannosaurus rex from the McRae Formation
(Lancian, Upper Cretaceous),Elephant Butte Reseruoir, Siena County, New Mexico: New Mexico
Geological Society, Guidebook to the 37th Field
Conference, pp. 235-238.
Harland, W. B., Armstrong,R. L., Cox, A. V, Craig,
L.E., Smith, A. G., and Smith, D. G., 1990,A geologic tine scale 1989:Cambridge University Press,
New York, 263 pp.
Hodgson, S. A.,7991,, The geology and tectonics of
the northem Little Hatchet Mountains, Grant and
Hidalgo Counties, southwesternNew Mexico: Unpublished MS thesis,New Mexico StateUniversity,
Las Cruces, 117 pp.
La Rocque,A., 1960,Molluscan faunasof the Flagstaff
Formation of central Utah: Geological Society of
America, Memoir 78, 100 pp.
Lasky, S. G., 7947,Geology and ore deposits of the
Little Hatchet Mountains, Hidalgo and Grant
Counties, New Mexico: U.S. Geological Survey,
ProfessionalPaper 208, 101 pp.
Lawton, T. F., and Clemons, R. E., 192, Klondike
Basin-late Laramide depocenterin southern New
Mexico: New Mexico G-eology,v. 14, no. 1, pp.
7J.
lawton, T. F., Mack, G. H., Basabilvazo,G. T., Wilson, D. A., Lucas,S. G., and Kietzke,K. K., 1990,
Uppermost Cretaceousand Paleoceneshata in the
Little Hatchet Mountains, southwesternNew Mexico (abs.):New Mexico Geology,v. 12, no. 1, p. 15.
Lipman, P W., and Hagshum, J. T., 1992, furassic
ash-flow sheets,calderas,and related intrusions of
the Cordilleran volcanic arc in southeastern Arizona: implications for regional tectonics and ore
deposits: Geological Society of America, Bulletin,
v.70/., pp.32-39.
Lipman, P W., and Sawyer, D. A., 1985:Mesozoic
ash-flow calderafragmentsin southeasternArizona
and their relation to porphyry copper deposits:Geology, v. 13, pp.552-656.
Loring, A. K., and Loring, R. 8., 1980,ISAI agesof
middle Tertiary igneous rocks from southern New
Mexico: Isochron/Vvest,no. 28, pp.17-19.
Lucas,S. G., Basabilvazo,G. T., and Lawton, T. F.,
1990,Late Cretaceousdinosaursfrom the Ringbone
Formation, southwestern New Mexico, U.S.A.:
CretaceousResearch,v. 11, pp. 343-349.
Lucas,S. G., and Gonziilez-Le6n,C.,1990, RePorte
preliminar sobre dinosarios del Cret6cicoTaldio de
ia cuenca de Cabullona, Sonora: Universidad de
Sonora, Departemento Geologia Boletin, v. 7, no.
1.,pp. 1-6.
Marvin, R. G., Naeser, C. W., and Mehnert, H.H.,
L978, Tabulation and radiometric ages-including
unpublished K-Ar and fission-hackages-for rocks
in southeastern Arizona and southwestern New
Mexico: New Mexico Geological Society, Guidebook to the 29th Field Conference, PP.243252.
Rosaz, T., 1989, Le passage des Cordilldres nordam6ricains aux Sienas Madres mexicainesle long
du Texas Lineament- G6ologie de SW du Nouveau-Mexique (USA): Bulletin Centres de RechercerExploration-Production Elf Aquitaine, v.
13, pp.247-275; New Mexico Bureau of Mines and
Mineral Resources,Open-file Report 385 [in French,
with English summary and captions].
Seager,W. R., 1983, Laramide wrench faults, basement-cored uplifts, and complimentary basins in
southern New Mexico: New Mexico Geology, v. 5,
PP. 69-76.
Seager,W. R., and Mack, G. H., 7986,Laramide paleotectonicsof southern New Mexico; in Peterson,
f . A., (ed.), Paleotectonicsand sedimentationin rhe.
Rocky Mountain region, United States:American
Association of Petroleum Geologists, Memoir 41,
pp. 559-685.
Seager,W. R., Mack, G. H., Raimonde, M. S., and
Ryan, R. G., 1986,Laramide basement-coreduplift
and basinsin south-centralNew Mexico:New Mexico GeologicalSociety,Guidebook to the 37th Field
Conference, pp. 123-130.
Thoman, C. H., and Drewes, H., 1980,Geologicmap
of the Victorio Mountains, Luna County, southwestern New Mexico: U.S. Geologic Survey, MiscellaneousField StudiesMaP MF-1175,vale 1':24,ffi0.
Wilcox, R. E., Harding, T. P, and Seely,D. R.,1973,
Basic wench tectonics: American Association o{
Peholeum Geologists, Bulletin, v. 57, pp. 74-96.
Wilson, D. A., 7997, Depositional environments,
provenance, and age deterrnination of the Skunk
RanchFormation, Little Hatchet Mountains, southwestem New Mexico:Unpublished MS thesis,New
Mexico State University, Las Cruces, 87 pp.
Zeller, R. A., Jr., 1970,Geology of the Little Hatchet
Mountains, Hidalgo and Grant Counties, New
Mexico: New Mexico Bureau of Mines and Mineral
Resources,Bulletin96,22pp.
tr
continental deposits of New Mexico: an overuiew:
Geological Society of America Bulletin, v. 92, pp.
9r7-932.
horse
Lucas,S. G., and Logan,T. R., 1984,Pleistocene
from the Albuquerque area, New Mexico: New
MexicoJournalof Science,v.24, pp.29-j2.
Lucas, S. G., and Oakes,W., 1985,Pliocene(Blancan)
vertebrates from the Palomas Formation, southcentral New Mexico: New Mexico Geological Society, Guidebook to 37th Field Conference,pp. 249255.
Lucas, S. G., Williamson, T., and Sobus,J., 1988,Late
Pleistmene (Rancholabrean)mammals from the Edith
Formation, Albuquerque, New Mexico: New Mexico Journal of Science,v 28, pp. 51-58.
MacFadden, B. J., Dn, Magnetic polarity stratiSraphy of the Chamita Formation shatotyPe (MioPliocene) of north-central New Mexico: American
Journal of Science,v. 277, pp. 769-800.
Machette, M. N., 1978a,Geologic map of the San
Acacia quadrangle, Socorro County, New Mexico:
U. S. GeologicalSurvey,GeologicQuadrangleMaP
GQ-141s.
Machette, M. N., 1978b,Prelininary geologicrnap of
the Socorro 1" x 2'quadrangle, central New Mexico: U.S. Geological Suruey, Open-file RePort 78ffi7.
Machette, M. N., 1978c, Quaternary faults in the
southwestern United States by using buried calcic
paleosols:Journal of Research,U.S. GeologicalSurvey, v. 5, pp. 359-381.
Madden, C., 1981,Mammoths olNorth America: Unpublished PhD dissertation, University of Colorado,241.pp.
Manley, K., 1978, Geologic map of Bernalillo NW
quadrangle, Sandoval County, New Mexico; U. S.
GeologicalSurvey, Geologic Quadrangle Map GQtMs.
Olsen, S. J., 1979, Osteology for the archaeologist:
Peabody Museum, Cambridge, 186 pP.
O'Neill, F. M., and Rigby,J. K.,Jr.,1982, A rare-fossil
from Pleistocenedepositsnear
skeletonof Carzelops
Albuquerque: New Mexico Geological Society,
Guidebook to 33rd Field Conference.pp. 82-84.
Osborn, H. F., 1918,Equidae of the Oligocene, Miocene, and Pliocene of North America, icono$aphic type revision: Memoir of the American
Museum of Natural History new series, v 2, pp.
1_330.
Smith, R. L., Bai)ey,R. As., and Ross,C. 5.,1970,
Geologic map of the JemezMountains, New Mexico: U.S. Geological Survey, Miscellaneous Geologic Investigations MaP I-571.
Tedford, R. H- 1981, Mammalian biochronology of
the late Cenozoicbasinsof New Mexico:Geological
Society of America Bulletin, v.92, pp- 1008-10a?.
Tedford, R. H., 1982, Neogene stratigraphy of the
northwestem Albuquerque Basin: New Mexico Geological Society, Guidebook to 33rd Field Conference,pp. 273J78.
Voorhies, M.,1969, Taphonomy and population dynamics of an early Pliocenevertebratefauna, Knox
County, Nebraska: University of Wyoming Contributions to Geology, SpecialPaper2, 69 pp.
Webb, S. D.,1965, The osteologyof Camelops:Science
Bulletin of the Los Angeles County Museum, v. 1,
Y pp.
White, J. A., 1987,The Archaeolaginae(Mammalia,
Lagornotpha) of North America, excluding ArclueoIagus and Palolax: Journal of Vertebrate Paleontology, v. 7, pp. 425-450.
sedimenWilliams, G. E., and Rust, B. R., 1977,Thre
tology of a braided river: Joumal of Sedimentary
Petrology, v. 39, pp. 649-679.
Wright, H. E., Jr., 1946,Tertiary and Quaternary geolbgy of the lower Puerco area, New Mexico: Geotogical Socieg of America Bulletin, v. 57, pp. 383456.
t-Xl€-tl-ttt:tt-xl--tt-Xt-Xl:tt:tt:llC-ll-ll-)ll-l
Lucas et al.
(Continued from p. 8)
Kurten, 8., and Anderson, E., 1980,Pleistocenemammals of North America: Columbia Universitv Press,
New York, zM2pp.
Lambert, P W., 1958,Quaternary stratigraphy of the
Albuquerque area, New Mexico: Unpublished PhD
dissertation, University of New Mexico, 329 pp.
Lambert, P. W., 1978, Upper Santa Fe stratigraphy
and geomorphic feahrres of the Llano de Albuquerque: New Mexico Bureauof Mines and Mineral
Resoutces,Circular 163, p. 151.
Logan, T. R., 1984,Early Iruingtonian (early Pleistocene) mammals from the upper part of the Santa
Fe Group, Albuquerque-Belen Basin, cenkal New
Mexico: Geological Society of America, Rocky
Mountain Section, Abstracts with Programs,v. 16,
no. 4, p. 245.
Logan, T. R., Lucas, S. G., and Sobus,J. C., 1984,
Blancan-Iwingtonian boundary in the Ceia Member of the Santa Fe Formation, Tileras Arroyo, Albuquerque area, New Mexico: New Mexico Geology,
v. 6, no. 1, p. 14.
Lozinsky,R. P, Hawley,J.W., andLove, D.W.,1991,
Geologic overuiew and PlioceneQuatemary history of the Albuquerque Basin,centralNew Mexico:
New Mexico Bureau of Mines and Mineral Resources,Bulletin 737,p.157-162.
Lozinsky, R. P., and Tedford, R. H., 1991,Geology
and paleontology of the Santa Fe Group, southwestern Albuquerque Basin, Valencia County, New
Mexico: New Mexico Bureau of Mines and Mineral
Resources,Bulletin 132, 35 pp.
Lucas,S. G., 1987,American mastodontfrom the Sandia Mountains, New Mexico: New Mexico Journal
of Science,v.27, pp.2912.
Lucas, S. G., and Effinger, J. A., 1997,Mammuthus
from Lincoln County and a review of the mammoths from the Pleistoceneof New Mexico: New
Mexico GeologicalSociety,Guidebook to 42nd Field
Conference, pp. 277282.
Lucas, S. G., and Ingersoll, R. V., 1981, Cenozoic
Nan Mexico Geology February 1993