Gretaceous
stratigraphy
andbiostratigraphy,
Clayton
LakeStatePark,Union
Gounty,
NewMexico
bySpencer
G. Lucas,
Adrian
P.Hunt,Kenneth
K. Kietke,Department
University
Albuquerque,
NM87131
of Geology,
of NewMexico,
andDonald
L. Wolberg,
NewMexico
Bureau
andMineral
NM87801
of Mines
Besources,
Socorro,
Introduction
Establishedin 7966,Clayton Lake StatePark is a dam, lake, and
recreationarea in the valley of Seneca(also known as Cieneguilla)
Creek 11 mi northwest of Clayton, New Mexico (Fig. 1). Cretaceous
sedimentaryrocks and upper Cenozoicalluvium and basaltcrop out
in the state park (Baldwin and Muehlberger,1959;Foster,1983).In
1982,Clayton Lake State Park took on paleontologicalsignificance
when the existenceof nearly 500 dinosaur footprints af the dam
spillwaywas brought to scienlificattention. Subsequentdescriptions
of this dinosaurichnofauna(Gilletteand Thomas,1983,I98S;Gillette
et al., 1.985;Thomas and Gillette, 1985)identified the track-bearing
horizon as the Dakota Sandstoneof Aptian-Albian (Earlv Cretal
ceous)age. In this paper,we clarify the rock-stratigraphic
ind biostratigraphicrelationshipsof the Cretaceousstrata at Clayton Lake
with particular emphasison the dinosaur-footprint-bearingstrata.
Stratigraphy
Stratigraphicdata for Clayton Lake StatePark were provided by
Baldwin and Muehlberger(1959)and Gillette and Thomis (1985).I;
their geologicmapping of Union County (scale1:125,000),
Baldwin
and Muehlberger (1959,pl. 1a) assigned the Cretaceousbedrock
around Clayton Lake to the Dakota Formation. Gillette and Thomas
(7985,fig.5) acceptedthis stratigraphicdesignationand presented
a measuredstratigraphicsectionof the "principal strataof the Dakota
Formation exposedat the spillway at Clayton Lake Statepark."
Our measuredstratigraphicsectionsat Clayton Lake (Tables1, 2)
indicate that five distinct rock-stratigraphicunits are exposedin the
statepark (Fig. 2). Basedon lithology alone, these five units can be
correlatedwith Cretaceousstratain east-centralNew Mexico (Harding, San Miguel, Guadalupe,and Quay Counties)with confidence.
Thus, the light-gray shale below the dam spillway (Fig. 2, sec. B,
unit 1; Fig. 3A.)resemblesthe TucumcariShaleof east-ientralNew
Mexico.The 12.8m of grayish orange,trough-crossbeddedand rip-
pleJaminated,quartzosesandstonethat overlie this shaleand thus
floor the lower part of the dam spillway (Fig. 2, sec. B, unit 2; Fig.
3, B-D) are remarkablysimilar to the fluvio-deltaicMesa Rica Sandstone farther south. The lowest of three stratigraphichorizons that
containdinosaurfootprints is near the top of this sandstone(Gillette
and Thomas, 1985,fig. 5). The upper two dinosaur-footprint horizons occur in a thin sequence(about 4 m thick) of interbedded silty
shale,shalysiltstone,and quartzosesandstonethat is predominantly
gray (Fig. 2, sec.B, units 3-13; Fig. 3E-F) and differs little from the
PaiaritoShalein east-centralNew Mexico. On the south shoreof the
h(e, these strata (Fig. 2, sec.A, units 1-11; Fig. 3G) are overlain by
22.5m of quartzosesandstonethat is mostly yellowish orange and
intensively bioturbated (Fig. 2, sec. A, units L2-15; Fig. 3G). This
sandstoneunit corresDondswell with the Dakota Sandstoneas used
in a restrictedsenseby Wanek (L962)and Lucas and Kues (1985)in
east-centralNew Mexico. The gray shale above this unit south of
Clayton Lake (Fig. 2, sec.A, unit 15; Fig. 3G-H) resemblesthe Graneros Shale, an Upper Cretaceousmarine unit present above the
Dakota Sandstonethroughout Union County (Baldwin and Muehlberger, 1959; Kauffman et al., 1969). Upper Cenozoic calcareous
sandstonetruncatesthe GranerosShaleat Clayton Lake (Fig. 2, sec.
A, unit 17).
Foraminiferafrom the units at Clayton Lake here correlatedwith
the TucumcariShaleand GranerosShalesupport thesestratigraphic
correlations(see discussionbelow). However, there are two other
approachesto the rock-stratigraphicnomenclatureof the Cretaceous
strataat Clavton Lake that should be considered.
First, use'of the term Dakota Sandstonein a broad sense (as a
group) to include the Mesa Rica Sandstoneand Pajarito Shale as
lower and middle units of a tripartite Dakota is nlausible, as used
in SanMiguelCounty by Jackaand Brand(1972),Gilbertand Asquith
(1976),Bejnar and Lessard(1.976),
and Mateer (1985).We, however,
oppose this broad usage of the term Dakota in northeasternNew
Mexico because:1) the Mesa Rica and Pa;'aritoare lithologically dis-
' . , . ^ . . .
^ . , . v . . ,
t
lo
\l
rl
:'..1
:
_ B o u n d o r yo f C l o y l o n
/ Loke Slole Pork
r )
r-.J
-
,/ )-'-
Meosured
/seclton
Loke^rs
Meosured ./
s e c t i o nA . , /
J 4.-,/
D o ms p i l l w o y
o n dd i n o s o u r
lrockwoys
-ll mi
- 1 7 . 6k m
FIGURE 1-Map of Clayton Lake and vicinity showing locations of measured stratigraphic sections
(Fig. 2; Tables 1 and 2) and dinosaur trackways.
August 1986 Nan MexicoGeology
tinct, widely exposed, and mappable units and; 2) the late Albian
Mesa Rica Sandstone antedates and thus is not homotaxial with the
Cenomanian Dakota Sandstone of northwestern New Mexico (Peterson and Kirk, 1.977;Molenaar, 1983), contrary to a correlation
proposed by Scott (1.970).
Second, the term Purgatoire Formation was applied by Baldwin
and Muehlberger (1959) throughout Union County to the strata at
Clayton Lake we correlate with the Tucumcari Shale. We accept
Baldwin and Muehlberger's (1959) usage of the term Purgatoire and
thus recognize the oldest Cretaceous strata exposed at Clayton Lake
as the Glencairn Shale, the upper member of the Purgatoire, and
the equivalent of the Tucumcari Shale in northeastern New Mexico,
southeastern Colorado, and western Oklahoma (Scott, 1970). The
strata above the Purgatoire at Clayton Lake thus could be called
Dakota (Baldwin and Muehlberger, 7959)or Mesa Rica, Pajarito, and
Dakota (this paper) overlain by Graneros Shale.
Clearly, the alternative nomenclatures applicable to the Cretaceous
strata at Clayton Lake indicate a need tb- chrify the usage of the
terms Purgatoire and Dakota in northeastern New Mexico. Currently
we prefer restriction of the term Dakota to the marine sandstone
immediately below the Graneros Shale, but we recognize that the
problems of Dakota terminology in the northeastern portion of New
Mexico are complex, and their complete resolution is beyond the
scope of this paper. Similarly, we apply the name Glencairn Shale
Member of the Purgatoire Formation to the oldest Cretaceous strata
exposed at Clayton Lake, recognizing its equivalence to the Tucumcari Shale of east-central New Mexico and, therefore, the redundancy
of the names Tucumcari and Glencairn. The important point is that
whichever names are applied to the dinosaur-track-bearins strata at
Clayton Lake these straia are equivalent to the units cal'ied Mesa
Rica Sandstone and Paiarito Shale in east-central New Mexico.
C l o y f o nb o s o l t s
n
m
l;.-1
r.']:.:i
[:
S s - - p l o n o rc r o s s b e d s
w
S s - - t r o u g hc r o s s b e d s
E
tfl
S s - -l o m i n o r
tr
S s - - m o s s i v e( i n l e n s i v e l v
b i o t u r b ot e d)
t"1
Dokoto
Sondstone
S s - - r i p p l el o m i n o r
l- --.1
[.:--.11
-
Biostratigraphy
Invertebrate microfossils (principally Foraminifera and Ostracoda)
and/or megafossils (Mollusca) indicate that the Glencairn Shale and
its equivalent, the Tucumcari Shale, are late Albian in age, correlatives of the Duck Creek Formation of the Washita Group of western
Texas (Scott, 1970;Kietzke, 1985; Kues et al., 1985). A sample of the
Glencairn Shale from Clayton Lake contained a small assemblage of
Albian arenaceous Foraminifera. Characteristic sr>eciesin this assemblage include Ammobaculoidesplummerae,A. ?phaulus,Ammodiscus
ganitinus, Ammobaculitessubcretaceus,Quinqueloculinananna, Reophax
sp., Dentalina cf . D. cylindroides, and Nodosariasp. These are Albian
taxa known from the Kiowa Shale of Kansas (Loeblich and Tappan,
1950), the Duck Creek Formation of Texas (Tappan, 1,943), andlor
the Tucumcari Shale of east-central New Metco (Brooks , L959;I1etzke,
:
ffi
P oj o r i t o
Shole
D i n o s o uf or o t p r i n i s
Tholassinoides
Dinosour footorints
198s).
Similar microfossil and megafossil evidence indicates that the Graneros Shale of northeastern New Mexico and adjacent areas is of
early Cenomanian age (Kauffman et a1., L969,7977; Cobban, 1984).
At Clayton Lake a sample of the Graneros Shale contained an assemblage of arenaceous Foraminifera dominated by Bigenerina hastata, Haplophragmium arenatus, Trochamminasp., Heterohelixglobulosa,
and Guembelitriaharrisi. Lamb (1968, table 1) reported these taxa from
MesoRico
the Graneros Shale of the San Juan Basin of northwestern New
Sondstone
Mexico and southwestern Colorado.
Although Scott (1970) considered the Mesa Rica Sandstone to be
8-'
primarily of Cenomanian age, the presence of the index ammonoid,
1''
Mortoniceras equidisttms,in the Mesa Rica in Guadalupe County indicates that the lower part of this unit is middle late Albian ikues
et al., 1985). Therefore, marine invertebrates from subjacent and
superjacent stratigraphic units bracket the age of the uppermost
Mesa Rica Sandstone and the Pajarito Shale as latest Albian or earliest
Cenomanian. A more exact age determination for these strata cannot
be made from current evidence.
Glencoirn
SholeMember
Bejnar and Lessard (1976, p.161) listed the following taxa of spores
PurgotoireFormofion
and palynomorphs from their "Middle Shale Unit" of the Dakota
Group (: Pajarito Shale) in San Miguel County: Cicatricosisporites
cf .
C. magnus, C. dorogensis,Lycopodiaciditessp., Dictophyllidites sp., Cyathidites sp., Alisporites sp., and Schizocystiacf . S.Iaeztigata.They con- FIGURE 2-Measured stratigraphic sections at Clayton Lake. SeeFig. 1 for
cluded that "the overlapping ranges of the pollen and spores from
locationsof sectionsand Tablesl and2 for descriptionsof lithologic units.
Nar Mexico Geology August 7986
the Middle Shale Unit indicate an upper Lower Cretaceous age (either However, examination of more recent studies of Early Cretaceous
Aptian or Albian) for the unit" (Bejnar and Lessard, 1976, p. 161). spores and palynomorphs (e.g., Srivastava,1981;Tschudy et al.,
1984)suggeststhat these taxa are long-ranging forms of no use in
distinguishing Early from Late Cretaceous.
TABLE1-Section A. Measuredfrom the south shoreof ClaytonLakethrough
The only megafossilinvertebrateknown from the Pajarito Shale
the recreation area to the top of the vallev south of the lake in the
which was reportedby Dobrovolny et al. (1946)
SW1/sNW1/+SW1/+
and NW1/sSWt/nSW,/n
sec. 15, T27N, R34E.Strataare es- is Lophaquadruplicata,
sentiallyflatJying. This sectionwas measuredwith a Brunton compassand from Puerto Canyon in Quay County. This taxon has a range of
1.S-m-longstaff;colors from the rock-colorchart of Goddard et al. (7979). Albian through early Cenomanian (Scott, 1970;Kues et al., 1985),
Unit
18
Description
Claytonbasalts:
Basalt, dusky brown (5 YR 212)and grayish black
(N 1).
Nonconformity
Quaternaryalluztium:
77
Sandstone, quartzose and calcareous, medium
grained, well rounded, well sorted, very pale
orange (10 YR 8/2).
Disconformity
Graneros Shale:
1,6 Shale, iron stained locally, light gray (N 7) and pale
yellowish orange (10 YR 8/6; Fig. 3H).
Dakota Sandstone:
l5
Sandstone, quartzose, fine grained, subangular,
well sorted, silica cement, very pale orange
(10 YR 8/2), forms a low bench.
t4 S a n d s t o n e , m o s t l y c o v e r e d b y a l l u v i u m ,
vegetation, and the asphalt roadway; but like
unit 15 where visible.
13 Sandstone, quartzose, medium to fine grained,
subangular, poorly sorted, iron stained, dark
yellowish orange (10 YR 6/6), but weathers
moderate brown (5 YR 3/4); low-angle planar
crossbeds and ripple laminae.
t 2 Sandstone, quartzose, fine grained, subangular,
well sorted, silica cement, grayish orange (10 YR
7/4), massive (intensively bioturbated) except for
some preserved channel bottoms.
ralaruo Jnate:
1 1 Sandstone, quartzose, fine to very fine grained,
subrounded, moderately well sorted, silica
cement, some kaolinite, yellowish gay (5Y 712),
intensively bioturbated (many vertically oriented,
tubular burrows preserved), plant debris on top
bedding plane.
l0
Interbedded siltstone and sandstone; siltstone is
slightly micaceous, some carbonaceous debris,
light gray (N 7); sandstone is quartzose, fine
grained, subangular, moderately well sorted,
yellowish gray (5 Y 712) and,locally, dark
yellowish orange (10 YR 6/6).
9
Sandstone, quartzose, fine grained, subangular,
poorly sorted, silica cement, some kaolinite,
grayish orange (10 YR7l4),low-angle planar
crossbeds, clav pebbles at base.
8
Same lithology is unit 10.
7 Same lithology as unit 9.
6
Same lithology as unit 10.
5 Sandstone, quartzose, medium grained,
subangular, moderately well sorted, silica
cement, some kaolinite, yellowish gray (5 Y 8/1),
trough crossbeds, clay pebbles at base, some
plant debris.
4
Same lithology as unit 10.
3
Sandstone, quartzose, fine to medium grained,
subangular, very poorly sorted, sihca cement,
much kaolinite, yellowish gray (5 Y 712) to dark
yellowish orange (10 YR 6/6), generaily massive
with some very low angle trough crossbeds.
2
Sandstone, quartzose, fine grained, subangular,
moderately well sorted, silica cement, some
kaolinite, light gray (N 7), laminar bedding.
1
Sandstone, quartzose, fine to medium grained,
subrounded, poorly sorted, silica cement, trace
kaolinite, light olive gray (5 Y 6/1), intensively
bioturbated, ripple marks on top bedding plane.
Water leael of Clauton Lake
August 1985 Nao Merico Ceology
Thickness (m)
and, thus, it does not aid in refining the age of the Pajarito.
Approximately 500 dinosaur footprints are present in the Mesa
RicaSandstoneand the PaiaritoShalein the dam spillway at Clayton
not measured
fromthebaseof thedamspillwayat Clayton
TABLE2-sectionB. Measured
9
Lake to the low hill above the spillway in the SW1/+NE1/+sec. 15, T27N, R34E
(see Fig. 1). Strata dip 18" to N60"E. This section was measured with a Brunton
compass and 1.S-mlong staff; colors from the rock-color chart of Goddard
et aL. (7979\.
Unit
2.4
6.5
2.3
11.3
0.6
1.3
Holocenesoil:
Not described or measured.
Disconformity
Pnjarito Shale:
13
Sandstone, quartzose, fine grained, subrounded to
rounded, moderately well sorted, silica cement,
some kaolinite, unweathered light gray (N 7),
weathers to dark yellowish orange (10 YR 6/6)
and pale brown (5 YR 5/2), intensively
bioturbated (Fig. 3F).
12
Sandy, siltstcne; siltstone is noncalcareous, light
gray (N 7); sandstone is quartzose, very fine
grained, subangular, dark yellowish orange (10
YR 6/6).
11
Sandstone, quartzose, fine grained, subrounded,
moderately well sorted, silica cement, much
kaolrnite, yeilowish gray (5 Y 712), grayish orange
(10 YR 7/4) and dark yellowish orange (10 YR 6/
6), laminar.
1 0 Same lithology as unit 12.
9 Sandstone, quartzose, very fine grained,
subangular, moderately well sorted, silica
cement, some kaolinite, yellowish gray (5Y 712)
and dark yellowish orange (10 YR 616),massive,
hematitic stains, some plant debris, highest
dinosaur footprint horizon (Gillette and Thomas,
8
7
0.8
6
0.1
0.3
1.3
0.8
5
4
3
0.4
1.5
Description
2
0.3
2.0+
1
1985,fig. s).
lithologiesof units6 and7.
Interbedded
Sandstone, very fine grained, quartzose, silica
cement, some kaolinite, subangular, well sorted,
medium dark gray (N 4), thin laminae, very well
indurated.
Silty shale, slightly micaceous, noncalcareous,
some carbonaceous debris, medium gray (N 5).
Same lithology as unit 7.
Sandstone, quartzose, fine grained, subangular
moderately well sorted, silica cement, some
kaolinite, grayish orange (10 YR714) to dark
yellowish orange (10 YR 6/6), intensively
bioturbated, main dinosaur footprint horizon
(Gillette and Thomas, 1985, fig. 5).
Siltstone, noncalcareous, medium gray (N 5).
Mesa Rica Sandstone:
Sandstone, quartzose, medium to coarse grained,
subrounded to rounded, poorly sorted, grayish
orange (10 yR 714)unweathered, weathers to
dark yellowish orange (10 YR 616);bedforms
range from planar crossbeds to ripple laminae
(Fig. 3C) to trough crossbeds (Fig. 3B); clay
pebbles and gravel present in trough bases,
Thalassinoides
burrows on top bedding plane (Fig
3D), lowest dinosaur footprint horizon near top
of this unit (Gillette and Thomas, 1985, fig. 5)
Purgatoire Formation (Glencairn ShaleMember):
Shale, micaceous, noncalcareous, medium light
gray (N 6); unit mostly covered by soil and
vegetation (Fig. 3A)
Thickness (m)
1 . 0+
0.01
0.8
0.3
0.5
0.8
0.03
0.03
0.03
0.3
0.08
12.8
not measured
mber of Purgatoire Formation (KP), overlain by Mesa Rica Sandstone
4esa Rica Sandstone in the dam spillway; C, ripplelaminated sandstone
rws on the top surface of the Mesa Rica Sandstone in the dam spillway;
.o Shale in the dam spillway (see Fig. 4 for detail); F, top sandstone of
ring Pajarito Shale (KP), Dakota Sandstone (KD), Graneros Shale (KG)
tre of lake
Nm MexicoGeology August 1986
53
Lake (Figs. 3E, 4). In a seriesof abstractsand a paper, Gillette and
Thomas (1983,1985;Gillette et al., 1985;Thomas and Gillette, 1985)
discussedthe taxonomy and biostratigraphicsignificanceof these
tracks.According to these workers, at least four different types of
trackscan be recognizedthat representthree theropod taxaand one
(or more?)ornithopod taxon.The ornithopod trackshavethe greatest
biostratigraphicpotential becauseit is possible to distinguish the
iguanodontids(primarily Early Cretaceous)from hadrosaurids(primarily Late Cretaceous).However, no consistent identification of
the ornithopod footprints from Clayton Lake has been presented.
Thus, these tracks have been assignedto a camptosaur(known
mainly from the the Late furassic) and hadrosaurid (Gillette and
Thomas, 1983),iguanodontids and hadrosaurids(Thomasand Gillette, 1985),or possibly hadrosaurids,iguanodontids, and a "webfooted theropod" (Gillette and Thomas, 1985).As pointed out by
Gilletteand Thomas(1985),the majority of the ornithopod footprints
at Clayton Lake are similar to those of hadrosaurids describedby
Langsion (1960),Currie (1983),and Currie and Sargeant(7979).The
presenceof blunt hoof impressionsand the relatively small lengthto-width ratio of these tracks distinguishesthem from the tracks of
FIGURE 4-Footprint of a small theropod dinosaur in the Pajarito Shale at
iguanodontids (Currie, 1983).
Despitethesediffering identificationsof the ornithopod footprints the dam spillway, Clayton Lake (Fig. 2, sec. B, unit 4).
from Clayton Lake, Gillette and Thomas (1985)and Thomas and
of the Dakota Group, San Mieuel and Mora Counties, New Mexico: New Mexico
Gillette (1985)assignedan Early Cretaceous(Aptian-Albian) age to
GeologicalSociery Guidebookto 27th Field Conference,pp. 757-763.
the trackwaysat Clayton Lake, believingthem to be correlativewith Brooks,
L. C., 1959, BiostratigraPhy of the Purgatoire Formation, west-central Quay
dinosaur tracks from the Dakota Group of central Colorado, which
County, New Mexico: Unpublished M S thesis, TexasTechnological College, Lubbock, 123 pp
were assignedan Aptian-Albian age by Lockley (1985a).However,
Lockley (1985b)subsequentlyconcluded that, in light of the work Cobban,W. A., L984,Mid-Cretaceousammonite zones, Western Interior, United States:
GeologicalSocietyof Denmark, Bulletin, v.33, pp.77-89.
of Scott(1970)and Tschudyet al. (1984),the Colorado trackwaysare Cunie, P., 1983, Hadrosaur trackways from the Lower Cretaceousof Canada: Acta
of late Albian or early Cenomanianage.
Polonica,v.28, pp. 45-50.
Palaeontologica
Like Gillette and Thomas (1985),we believe the maiority of or- Currie, P., and Sargeant, W. A. S., 7979, Lower Cretaceousdinosaur footprints from
the PeaceRiver Canyon, British Columbia: Paiaeogeography,Palaeoclimaiology,Panithopod tracks from Clayton Lake are hadrosaurids. Thi-smight
v 28, pp. 103-115.
laeoecology,
suggesta Late Cretaceous(ergo earliest Cenomanian)age for the Dobrovolny, E , Summerson, C. H , and Bates, R. L , 1946,Geology of northwestern
uppermost Mesa Rica Sandstoneand the Pajarito Shale. However,
Quay County, New Mexico: U.S. Geological Suruey, Oil and Gas Investigations Preliminarv Map PM-52, scale 1:62,500
in North America undoubted hadrosaurbody fossilsareknown from
Lower Cretaceousstrata (Galton and fensen, 1979)as are hadrosaur Foster,R, 1983,Clayton Lake: New Mexico Geology,v 5, no 4, pp 81-82
P M , and ]ensen, J A , 1979,Remainsof ornithopod dinosaurs from the Lower
trackways(Currie and Sargeant,1979;Currie, t983). Outside of North Galton,
Cretaceousof North America: Brigham Young University, Geology Studies, v.25, pp
America, iguanodontidsare known from the Upper Cretaceous(Ta1-10
quet, 1976)and may be present in the North American Upper Cre- Gilbert, j L, and Asquith, G 8., 1976,Sedimentologyof braided alluvial interval o{
Dakota Sandstone, northeastern New Mexico: New Mexico Bureau of Mines and
taceous as well. Thus, the possibility of latest Albian or earliest
Mineral Resources,Circular 1,50,16 pp.
Cenomanianiguanodontid and hadrosauridfootprints occurring to- Gillette,
D D , and Thomas, D. A , 7983,Dinosaur footprints in the Dakota Sandstone
gether, as may be the caseat Clayton Lake, cannot be discounted.
(Cretaceous)of northeastern New Mexico: Abstracts of the Annual Symposium on
SouthwesternGeology and Paleontology,Museum of Northern Arizona, Flagstaff,p
The many theropod footprints at Clayton Lake appear to have no
biostratigraphicutility for age discriminationwithin the Cretaceous. 7
7985, Dnosaur tracks in the Dakota Formation
Conclusions
Fiverock-stratigraphicunits of Cretaceousageare exposedat Clayton Lake StatePark in Union County. Theseunits are, in ascending
order, the GlencairnShaleMember of the PurgatoireFormation, the
MesaRicaSandstone,the PajaritoShale,the Dakota Sandstone,and
the GranerosShale.Arenaceousforaminiferansfrom the Glencairn
Shaleand GranerosShaleat Clayton Lake indicate late Albian and
early Cenomanianages, respectively,for these units. The dinosaur
footprints from Clayton Lake, in what we identify as the uppermost
Mesa Rica Sandstoneand the PaiaritoShale,are of latest Albian or
earliest Cenomanian age, not of Aptian-Albian age as previously
rePorted.
ACKNOWLEDGMENTS-We
are grateful to D. Gillette and D. Thomas
for freely sharing information *ith us on the dinosaur trackwaysat
Clayton Lake. Collaborativeefforts with M. Kisucky, B. S. Kue's,L.
C. Payne,and R. Wright to decipher the Lower Cretaceousstratigraphy of east-centralNew Mexico greatly influencedthe conclusions
reachedhere.We alsothank R. Foster,B. S. Kues,and O. j. Anderson
for their thoughtful reviews of an earlier version of this paper.
References
Baldwin, B., and Muehlberger,W R.,7959, Geologicstudiesof Union County, New
Mexico: New Mexico Bureau of Mines and Mineral Resources,Bulletin 63, 171 pp.
Beinar,C. R., and Lessard,R. H.,1976, Paleocunentsand depositionalenvironments
August 1985 New MexicoGeology
Gillette, D D , and Thomas, D A ,
(Aptian-Albian) at Clayton Lake StatePark, Union Counry, New Mexico: New Mexico
Geological Society,Guidebook to 36th Field Conference, pp. 283J88.
Gillette,D D, Pittman,J G , and Thomas,D A, 1985,Herding behaviorand species
diversity in Cretaceoussauropods of the American Southwest: Geological Socieiy of
America, Abstracts with Programs, v. 17, p 220
Goddard, E N, Trask, P D, DeFord, R K., Rove, O N, Singewald,J T, and Overbeck, R M., 1979,Rock-colorchart: Geological Society of America, Boulder
Jacka,A D., and Brand, J P., 1,972,An analysis of Dakota Sandstonein the vicinity of
Las Vegas, New Mexico, and eastward to the Canadian River valley: New Mexico
Geological Society,Guidebook to 27th Field Conference, pp. 105-107
Kauffman,E G., Hattin, D. E., and Powell, J. D., 1977,Stratigraphic,paleontologic,
and paleoenvironmentalanalysisof the Upper Cretaceousrocks of Cimanon County,
northwestem Oklahoma: Geological Society of America, Memoir 1'49,1'50pp.
Kauffman, E. G , Powell, J D , and Hattin, D F , 7969, Cenomanian-Turonian facies
acrossthe Raton Basin: The Mountain Geologist, v 6, pp 93-118
Kietzke, K. K, 1985, Microfauna of the Tucumcari Shale, Lower Cretaceousof eastcentral New Mexico: New Mexico Geological Society,Guidebook to 36th Field Conference, pp.247-260
Kues,B S, Lucas,S G, Kietzke,K K, andMateea N J, 1985,SynopsisofTucumcari
Shale,MesaRicaSandstoneand PajaritoShalepaleontology,Cretaceousof east-central
New Mexico: New Mexico Geological Society, Guidebook to 36th Field Conference,
pp 261)81.
Lamb, G. M , 1968, Stratigraphy of the lower Mancos Shale in the San Juan Basin:
GeologicalSociety ofAmerica, Bulletin, v 79, pp 827-854
Langston, W , 1960, A hadrosaurian ichnite: National Museum of Canada, Natural
History Paper 4, 9 pp.
Lockley, M G , 1985a,Dinosaur footprints from the Dakota Group of Colorado and
implications for iguanodontid-hadrosaurid evolution: GeologicalSociety of America,
Abstracts with Programs, v 17, pp 252)53.
Lockley, M G., 1985b,Vanishing tracks along Alameda Parkway, implications for Cretaceousdinosaurian paleobiology from the Dakota Group, Colorado; in Chamberlain,
C. K (ed.), A field guide to environments of deposition (and trace {ossils) of Cretaceous sandstonesof the Western Interior: Society of Economic Paleontologistsand
Mineralogists, Golden, pp 131-142
Loeblich, A. R., Jr., and Tappan, H., 1950, Foraminifera from the type Kiowa Shale,
Lower Cretaceous, o{ Kansas: University of Kansas, Paleontological Contributions,
Protozoa, art 3, pp 1-15.
Lucas, S G, and Kues, B S, 1985, Shatigraphic nomenclature and correlation chart
for east-central New Mexico: New Mexico Geoloeical Societv, Guidebook to 36th Field
Conference, pp 341-344.
Mateer, N f., 1985, Pre-Graneros Cretaceous stratigraphy of northeastern New Mexico:
New Mexico Geological Society, Guidebook to 36th Field Conference, pp 243-246
Molenaar, C. M, 1983, Major depositional cycles and regional conelations o{ Upper
Cretaceous rocks, southern Colorado Plateau and adiacent areas; rn Reynolds, M W,
and Dolly, E D (eds ), Mesozoic paleogeography of the west-central United States
Rocky Mountain paleogeography symposium 2: Society of Economic Paleontologists
and Mineralogists, Rocky Mountain Section, Denver, pp 207-224
Peterson, F., and Kirk, A. R., 1,977, Conelation of the Cretaceous rocks in the San Juan,
Black Mesa, Kaiparowits, and Henry Basins, southern Colorado Plateau: New Mexico
Geological Society, Guidebook to 28th Field Conference, pp 157-778
Scott, R W , 1970, Stratigraphy and sedimentary environments of Lower Cretaceous
rocks, southem Western Interior: American Association of Petroleum Geologists,Bulletin, v 54, pp 1225-1.2M
Srivastava,S K, 1981,Stratigraphicranges of selectedspores and pollen from the
FredericksburgGroup (Albian) of the southern United States:Palynology, v 5, pp
1.-26
Tappan, H , 1943,Foraminifera from the Duck Creek Formation of Oklahoma and Texas:
'1,7,
pp 476-577
Journal o{ Paleontology,v
Taquet,P, 7976,Geologieet paleontologiedu gisement de Gadoufaoua(Aptien du
Niger): Cahiers Paleontologie,Paris, 191 pp
Thomas, D A., and Gillette, D D , 7985, Omithopod ichnofauna in the Dakota Formation, Clayton Lake State Park, northeastern New Mexico: Geological Society of
America, Abstracts with Programs, v 1.7,p 267
Tschudy,R H, Tschudy,B D, and Craig, L C , 1984,Palynologicalevaluation of
Cedar Mountain and Burro Canyon Formations,ColoradoPlateau;U S Geological
Survey, ProfessionalPaper 7287,pp 1,)1,
geologicmap of parts of Harding, San Miguel,
Wanek, A A,1962, Reconnaissance
and Mora Counties,New Mexico:U S GeologicalSurvey,Oil and GasInvestigations
Map OM-208, scale1:96,000
I
Provisional
topographic
maps
(continued
from page57)
*Lovington SE
*Lovington SW
*Magdalena
*MagdalenaGap
*MagdalenaPeak
*Malaga
*Maljamar
*MaljamarNE
*MaverickMountain
*McCledeMountain
*Mcleod Tank
*Mesa Gallina
*MesaSarca
*MesasMojinas
*Midway
*Monument North
*Monument South
*Monument SW
*Mount Aden
*Mount Aden SW
*Mount Nebo (NM-CO)
*Mount Riley
*Mount Riley SE (NM-Mex
)
*Ned Houk Park
*Noria (NM-Mex
*OasisStatePark )
*Otis
*P A Mountain
*PleasantHlll (NM-TX)
*PleasantHill NE (NM-TX)
*PleasantHill NW
*PleasureLake (NM-TX)
*Portair
*PortairSW
*Portales
*Potrillo (NM-Mex.)
*Potrillo Peak
*RemudaBasin
*Riley
*Roughand ReadyHills
*SanLorenzo
*SanLorenzo Spring
*SilverCreek
*SleepingLady Hills
*Smith Ranch
*SmouseMesa
*St Vrain
*TaylorMountain
*TowerHill North
*Tower Hill South
*ThompsonMesa
*Turley
*WaterCanyon
*White Ridge
*WhitehorseMountain
*Williams Sink
1979-85
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32"45'
32"45'
Jt
32"15'
32"22',30',
32"7'30',
32"45',
32'52',30',
32'45',
32'45',
32"45',
34"37',30',
34"30',
34"37',30',
34"75',
.)Z
J/
J\J
32"30'
32"30'
32"7',30',
JL
36'52',30',
37"52',30',
31'45',
34'30',
37"45',
34"75',
32"75',
32"45'
34"30'
.)+ -) /
-)lJ
34"37'30',
34"15',
34"22'30',
34"15'
34'7'30',
31"45',
3r"52'30',
32"15',
34"22',30"
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36"22'30"
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J1
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103"15',
103"22',30',
107"7'30'
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707"7',30',
104'
103'45',
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707"7'30"
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107"
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730"22'30"
707"7',30"
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707'45',
707"
707"
703"7',30',
106"45',
103"15',
104"7'30'
107"37',30"
103"
103'
703"7',30"
103'
103"15',
703"22'30',
103'15',
706"52',30',
707"7'30"
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707"7'30"
707"
707"52',30',
107"
107"
107"
103'15',
r07"30'
103'22'30"
107"52'30',
103'52',30"
103'51',
107"37',30',
107"45',
107"
107"7'30"
r07"52',30',
r03"45',
5
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(continuedon page66)
New Mexico Geology Argust 1,986