green, calcareous mudstone and grayish-red- Texas. It contains a large, but generally frag- purple bioturbated sandy siltstone and is up to mentarv, dinosaur fauna. The dinosaur fauna of 37 m thick. Rock Point strata are up to 70 m the Buli Canyon Formation in New Mexico con- thick and consjst of laterally extensive beds of tains eight taxa. The largest theropods are two NewMexico Geological Society massi.ve, moderately reddish- brown sandy silt- new herrerasaurids (A, B), which are repre- stone and laminar to trough- crossbedded mod- sented by severai partial skeletons. A third, The New Mexico Geological Society eratelv reddish-brown ouartzose sandstone. smaller herrerasaurid (C) is only known from -..rri ' annual spring meeting was held at New Middle Jurassic(Entrada) to Upper Cretaceous vertebrae. Another smaller theropod (D) repre- Mexico Institute of Minins and Technol- (Dakota) strata disconformably overlie Upper sents a new taxon of uncertain affinities. S/'ru- Triassic Chinle Group rocks in the Lucero uplift. aosaurus sp. is known from one edentulous pre- ogy (Socorro) on April 8, f994. Following maxilla. A single dorsal centrum is the only are abstracts from sessions given at that Nrw Mrxrco's oLDEsr DrNosAUn.bv A. B. Heck- evidence for the presence of a prosauropod. meeting. Abstracts from the other sessions crf, Department of Earth and Pianetary Sci- Orinthischian teeth represent two species, appeared in 1994 issues of Nezu Mexico ences, lJniversity of New Mexico, Albu- Reaueltosauruscallenderi and Lucianosaurus wildi. Geology. This concludes the series from the querque/ NM 87131;S. G. Lucas,New Mexico A11 dinosaurs from the Bull Canyon Formation 1994 meeting. Museum of Natural History and Scrence, in Texas come from the Post quarrv and include 1801 Mountain Road NW, Albuquerque, NM Shuuosaurusinexpeclatus. Technosiurus smolli, a Structural geology and 87704; and A. P. Hunt, Department of Geol- prosauropod, and possibly Protoaais texensis. paleontology session ogy, University of Colorado at Denver,Cam- TWo dinosaur faunas can be distinguished in pus Box 172, P.O. Box 173364, Denver, Col- the Bull Canyon Formation. The lower fauna (Continued from last issue) orado 80277-3364 includes herrerasaurids A and C, theropod D, Tnresstc sTRATIGRApHyrN THE LucERo upLIFT, Recent work in west-central New Mexico has Shuaosaurus, a prosauropod, Reoueltosaurus, cENTRALNrw Mexrco, by 5. G. Lucas, New resulted in the discovery of the oldest known and Technosaurus. The upper fauna includes Mexico Museum of Natural History and Sci- dinosaur fossil in the state. Disarticulated cra- herrerasaurids B and C and Lucianosaurus. ence, 1801 Mountain Road NW, Albu- nial and postcranial remains of a small thero- Theropod dinosaurs discriminate three biogeo- querque/ NM 87104; and A. B. Hrcrrnl pod were found in the Bluewater Creek Forma- graphic provinces in the Late Triassic. A north- Department of Earth and Planetary Sciences, iion of the Chinle Group (NMMNH locality ern province (e. g. Western Europe) contains University of New Mexico, Albuquerque, 2739) near Fort Wingate in McKinley County, only ceratosaurs whereas a southern province NM 87131 along with isolated bone fragments of the (South America, South Africa, India) yields only herrerasaurids. A central province, which Triassic strata exposed in the Lucero uplift of labyrinthodont amphibian Buettneria and Phy- includes the United States,cbntains both cer- Cibola, Valencia, and Socorro Counties are non- tosauridae. The theroood was found in a atosaurs (e. g., Rioarribasaurus) and her- marine red beds of the Moenkopi Formation bluish-purple mudstone in the Bluewater Creek rerasaurids. Prosauropod distributions provide and Chinle Croup. Moenkopi formation strata Formation-approximately 10 m above its base some evidence for the recognition of three disconformably overlie middle Permian and about 29 m below the base of the McGaffey provinces with plateosaurids and the condon- (Guadalupian) limestones and dolomites of the Member. The presence of abundant Buettneria tosaurids being most common in the northern San Andres Formation and are as much as 55 m and Desmatosuilzas in the Bluewater Creek For- orovince, melanosaurids and blikanasaurids in thick. Moenkopi strata are latera1ly persistent mation, as well as its stratigraphic position ihe south, and prosauropods being rare in the benches of grayish-red, trough-crossbedded below the Blue Mesa Member of the Petrified central province. and rippleJaminated, micaceous litharenite Forest Formation, indicate it is of late Carnian intercalated with beds of intraformational con- (Adamanian) age. The cranium of this dinosaur glomerate and grayish-red, micaceous siltstone is represented by a single tooth, a lacrimal, and AprreN-ALeIeN BoUNDARy IN LowER CRETA- and mudstone. Charophytes, ostracods, and an occipital condyle. The tooth is laterally com- CEOUSSTRATA, SOUTHWESTERN NTW MTXTCO,bY capitosauroid amphibians indicate the pressed, serrated, and slightly recurved. The S. G. Lucas, New Mexico Museum of Natural Moenkopi Formation in the Lucero uplift is of lacrimal is distinctly L-shaped, as is typical in History and Science, 1801 Mountain Road Middle Triassic (early Anisian) age. Overlying basai theropods. The postcranial material NW, Albuquerque, NM 87104 Chinle Group strata consist of (ascending) the includes portions of the cervical, dorsal, and The Aptian-Albian boundary can be placed Shinarump, Bluewater Creek, petrified Forest, caudal vertebral series (30+ total vertebrae), using ammonite biochronology in the U-Bar Owl Rock, and Rock Point Formations. Shi- pelvic fragments, a distal femur, the proximal Formation of the Bisbee Croup in southwestern narump Formation strata are extrabasinal con- and distal ends of the left tibia. two nearlv com- New Mexico based on fossils collected in the glomerates (mostly Paleozoic limestone clasts) plete metapodials, phalanges, at leait two central Peloncillo, Little Hatchet, and Big and sandstones as much as 77 rn thick that dis- claws, and other fragmentary elements. The Hatchet Mountains. The most complete Apt- conformably overlie Moenkopi strata. Locally, vertebral centra are transverselv narrow and ian-Albian boundary sections in southwestern pedogenically modified sandstones, conglom- extensively hollowed, as are all lhe long bones New Mexico are located at U-Bar Ridge (sec. 1 erates, and siltstones-the "mottled strata"- of the limbs. The hollow nature of both the ver- T32S R16W) in the Big Hatchet Mountains and laterally replace Shinarump conglomerates and tebrae and the limb bones indicates that this east of Howells Ridge (sec. 12 T28S R16W) in sandstones. Bluewater Creek Formation strata dinosaur is a theropod similar to, albeit older the Little Hatchet Mountains. The youngest are as much as 50 m thick and are mostly red- than and smaller than, Rioarribasaurus colberti. Aptian strata of the U-Bar Formation are the dish-brown siltstones, mudstones, and ripple- This fossil is the second most comolete Triassic oyster-Iimestone member of Zeller in the Big laminated sandstones. The distinctive dinosaur known from New Merico. It orovides Hatchet and Little Hatchet Mountains (=Car- McGaffey Member-5-6 m of mostly ripple- insight into the origins of dinosaurs,not only in bonate Hill Formation of Gillerman in the cen- laminated sandstone-is present in the upper the American Southwest, but also in the world, tral Peloncillo Mountains). These strata yield half of the Bluewater Creek Formation. Below as it was contemporaneous with the earliest the ammonites Acanthoplites berkeyi Stoyanow, the McGaffey Member, the Bluewater Creek dinosaurs on other continents. This spring, Acanthoplites grandensis Scott, Acanthoplites hes- Formation contains an Adamanian (late Carn- additional matrix collected from NMMNH per Stoyanow, Hypacanthoplites immunities (Stoy- ian) tetrapod fauna that includes cf. Buettneria, locality 2739 will be screenwashed and should anow), Stoliczkaia patagonica Stoyanow, " Sonner- provide additional skeletal material. indeterminate phytosaurs, and Stagonolepis. ntia" fosteri Scott and Kazanskyella spnthi The base of the Petrified Forest Formation in the (Stoyanow). These ammonites identify the Lucero uplift is the Sonsela Member; evidently TUE otNoseun FAUNAoF THE BULL CeNyoN Fon- Kazanslcyellaspathi zone oflatest Aptian age. The the Blue Mesa Member has been removed bv varton (Urrun TRTASSTC:NomeN) oF EAST- oldest Albian strata of the U-Bar Formation are erosion at the pre-Sonselaunconformity. Son- CENTRALNgW MTxTCO AND WESTTExes ,qNI the limestone-shale member of Zeller, which sela strata are as much as 15 m thick and are THE BIOGEoGRAPHY oF LATE TRIASSIC overlies the oysterJimestone member in the Big mostly trough-crossbedded micaceous litharen- DINOSAURS/by A. P. Hunt, Department of Hatchet and Little Hatchet Mountains. This unit ite. Overlying Painted Desert Member strata are Geology, University of Colorado at Denver, contains a diverse invertebrate fauna domi- mostly reddish-brown bentonitic mudstone at Campus Box 772, P.O. Box 173364, Denveq nated by the ammonite Douuilleiceras mnmmila- least 100 m thick. Owl Rock and Rock Point co 80217-3364. tum and the nautiloid Cymatoceras neohispan- strata are only exposed in the Petaca Pinta area The Bull Canyon Formation is a Norian icum.The limestone-shale member thus belongs (SW % T6N RoW ina SE % T6N RZW). The Ow1 (Revueltian) red bed unit that is widely to the Douuilleicerasmnmmilatum zone of early Rock is mostly grayish- red and very pale exposed in east-central New Mexico and west Albian, but not eariiest Albian, age. Ammonite

February 1995 New Mexico Geology biochronology thus indicates a short hiatus in Barroll and Reiter Lucas the U-Bar Formation at the Aotian-Albian (Continuedtrom p. 13) boundary. This hiatus is equivalent to one (Continuedtrom p.7) ammonite zone, the earliest Albian Hypacantho- and potential: Transactions of the Geothermal Lucas, S. G., Hunt, A. P, and Morales, M., 1985, Strati- plites crngini zone. A marked lithologic change Resource Comcil, v 4,pp.6l-64. graphic nomenclature and correlation of Triassic rocks of east-central New Mexico: a preliminary from Exogyra packstones of the uppermost oys- Keller, C. R., and Cordell, L.,'1.983, Bouguer gravity anomaly map of New Mexico: New Mexico Energy report; in Lucas, S. G., and Zidek, J. (eds.), Santa ter-limestone member to calcareous shales and Instifute, Las Cruces. Rosa-Tucumcari region: New Mexico Geological ledgy, nodular limestones of the overlying lime- Reiter, M., Eggleston, R. E., Broadwell, B. R., and Society, Guidebook 36, pp. 1.77-1.84. stone-shale member is ohvsical evidence of the Minier, J., 1986, Estimates of terrestrial heat flow Marcou, J., 1858, Geology of North America, with two disconformity equivaleni to this hiatus. In from deep petroleum tests along the Rio Grande rift reports on the prairies of Arkansas and Texas, the southeastern Arizona, the Aptian-Albian in central and southern New Mexico: Journal of Rocky Mountains of New Mexico and the Sierra boundary is approximately ai the lower Geophys:ical Research, w 89L, pp. 6225-6245. Nevada of California: Zuricfu 144 pp. Mural-upper Mural contact, and in central Weia J. E., 1965. Geology and availability of ground Marzolf,J. E., 1993, Palinspastic reconstruction of early part sedimentary basins near the latitude of Texas it is at the contact of the Hensel Formation water in the northern of the White Sands Mis- Mesozoic sile Range and vicinity, New Mexico: U.S. Geologi- Las Vegas: implications for the early Mesozoic with the overlying Glen Rose Limestone, but at cal Suney, Water-supply Paper 1801, 78 pp. Cordilleran cratonal margin; in Drm, G., and these sections earliest Albian strata are Dresent. McDougall, K. (eds.), Mesozoic paleogeography of This suggeststhat tectonism local to southwest- the westem United States-Il: Pacific Section SEPM, ern New Mexico affected marine deoosition Appendix A Book7L, pp. 433462. during the Aptian-Albian transition. n Present status of "B" series wells McKee, E. D., 1954, Stratigraphy and history of the of Triassic age: Geological in area Moenkopi Formation the study Society of America, Memoir 61, 133 pp. We attempted to locate the "B" series of Molina-Carza, R., Geissman, J. W., and Lucas, S. G., magnetostratigra- the Bosque 1993, Late Carnian+arly Norian wells drilled by the USGS on phy from nonmarine strata, Chinle Group, New del Apache and described by Cooper Mexico: Contributions to the Triassic magnetic (1968). It was found that none of these oolaritv time scale and the correlation of nonmarine wells are accessible to a depth sufficient to ind mirine Triassic faunas: New Mexico Museum of Bulletin 3, pp. 345-352. allow temperature logging. (Subsurface Natural History and Science, Morales, M.,1987, Terrestrial fama and flora from the temperature data shallower than about 90 Triassic Moenkopi Formation of the southwestern ft islikely to be influenced by temperature United States: Journal of the Arizona-Nevada Acad- fluctuations at the surface, and so such emy of Science, v. 22, pp. 1.-19. O'Sullivan, R. B., 1974, The Upper Triassic Chinle For- data is of little usefulness.) mation in north-central New Mexico: in Siemers, C. B1-Apparently converted into a wind- T., Woodward, L. A., and Callender, J. F. (eds.), mill well, named Army well. We located Ghosi Ranch: New Mexico Geological Society, the well; it's an old broken-down wind- Guidebook 25, pp. 171-174. O'Sullivan, R. B., 1978, Principal mill, no longer operational. Now open to Pipiringos, G. N., and unconformities in Triassic and Jurassic rocks, West- about 40 ft (I2.2 m), it still has the wind- 'sucker ern Interior United Siates-a preliminary survey: U. mill rods' in it, making access to S. Geological Survey, Professional Paper 7035-4,29 the wellbore difficult. DD. Lucas, S. G., 1992, A Middle Triassic B2-Cooper (1968) states this well was Steiner, M. 8., and paleomagnetic pole for North America: Geological plugged and abandoned. Society of America, Bulletin, w 104, pp. 993-998. NewMexico Museum of B3-Cooper (1968) states this well was Steiner, M. 8., Morales, M., and Shoemaker, E. M., plugged and abandoned. 1993, Magnetostratigraphic, biostratigraphic, and NaturalHistory and Science B4-Cooper (1968) this well was lithologic correlations in Triassic strata of the west- states ern U.S.: SEPM, Special Publication 49, pp. 107-119. exhibit plugged and abandoned. Stewart, J. H., Poole, F. G., and Wilson, R. F.,'1.972a, B5-This well is described as being Stratigraphy and origin of the Chinle Formation and On June 3, 7995 the New Mexico drilled "on a topographical high in the old related Upoer Tiiassic strata in the Colorado Plateau , -; ^ ^ 1 Survey, Professional Paper Museum of Natural History and Science channel of the Rio Grande". We located region: U. S. Geological (Albuquerque) will open its new exhibit 690,336 pp. the well in 1990 in the present channel of Stewart, H., Poole, F. G., and Wilson, R. F., 1.972b, featuring Early Permian footprints found J. the Rio Grande, about 50 ft (15 m) from the Stratigraphy and origin of the Triassic Moenkopi in the Robledo Mountains near Las east shore in shallow water. There is a con- Formation and related strata in the Colorado "Ancient Plateau region: U. S. Geological Survey, Professional Cruces. The exhibit, Evidence: crete platform, which presumably was Life Before the Dinosaurs," focuses on the Paper 691, 195 pp. installed at about land surface, now about Tozer, E. T., 1984. The Trias and its ammonoids: the phenomenal fossil record of invertebrate 3 ft (-1, m) above the surface of the water, evolution of a time scale: Geological Survey of preserved and vertebrate tracks in Lower attached to the well casing. The casing had Canada, Miscellaneous Report 35, 169 pp. Permian strata of the Abo-Hueco transi- a cover with a rusted-out hinge. When we Tozer, E. T., 1994, Cmadlan Tiiassic ammonoid faunas: tional zone in Dofra Ana Countv. In quan- Geological Survey of Canada, Bulletin 467,663 pp. opened the cover, the hinge broke. Inside Visscher, H-, 1992, The new STS stage nomenclature: tity, quality of preservation,and diversity the casing we found a 1," pipe that led to a Albertiana, no. 10, p. 1. of trackmakers, the Dofla Ana County serrated metal collar, below which the Wood, G. H., and Northrop, S. A., 1946, Geology of the tracks are the best record on earth, one pipe seemed to widen, but which is Nacimiento Mountains, San Pedro Mountain, and that provides a unique glimpse of terres- adjacent plateaus in parts of Sandoval and Rlo blocked by a packer. Everything was Arriba counties, New Mexico: U.S. Geological Sur- trial life and locomotion some 280 million rusted and couldn't be budged. vey, Oil and Gas Investigations Map OM-57. n years ago. The exhibit, which occupies B6-Cooper (1968)reports this well was about 2,000 square feet, reconstructs the plugged and abandoned environment in which the tracks were B7-We located this well just west of the formed; Hueco Formation invertebrates road along a low-flow channel. The well and fossil driftwood are disolaved with was blocked just below the water level (no numerous tracks.The visitor is also taught more than 10 ft [3.05 m] deep). n how fossil tracks are studied and identi- fied. The New Mexico Museum of Natural History and Science is open 9am-5pm seven days a week; for more information, call (505)841-8837. tr

New MexicoGeology February 1995