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Sample records for jurassic navajo sandstone

  1. Supercritical CO2 Migration under Cross-Bedded Structures: Outcrop Analog from the Jurassic Navajo Sandstone

    NASA Astrophysics Data System (ADS)

    Lee, S.; Allen, J.; Han, W.; Lu, C.; McPherson, B. J.

    2011-12-01

    Jurassic aeolian sandstones (e.g. Navajo and White Rim Sandstones) on the Colorado Plateau of Utah have been considered potential sinks for geologic CO2 sequestration due to their regional lateral continuity, thickness, high porosity and permeability, presence of seal strata and proximity to large point sources of anthropogenic CO2. However, aeolian deposits usually exhibit inherent internal complexities induced by migrating bedforms of different sizes and their resulting bounding surfaces. Therefore, CO2 plume migration in such complex media should be well defined and successively linked in models for better characterization of the plume behavior. Based on an outcrop analog of the upper Navajo Sandstone in the western flank of the San Rafael Swell, Utah, we identified five different bedform types with dune and interdune facies to represent the spatial continuity of lithofacies units. Using generated 3D geometrical facies patterns of cross-bedded structures in the Navajo Sandstone, we performed numerical simulations to understand the detailed behavior of CO2 plume migration under the different cross-bedded bedforms. Our numerical simulation results indicate that cross-bedded structures (bedform types) play an important role on governing the rate and directionality of CO2 migration, resulting in changes of imbibition processes of CO2. CO2 migration tends to follow wind ripple laminations and reactivation surfaces updip. Our results suggest that geologically-based upscaling of CO2 migration is crucial in cross-bedded formations as part of reservoir or basin scale models. Furthermore, comparative modeling studies between 3D models and 2D cross-sections extracted from 3D models showed the significant three-dimensional interplay in a cross-bedded structure and the need to correctly capture the geologic heterogeneity to predict realistic CO2 plume behavior. Our outcrop analog approach presented in this study also demonstrates an alternative method for assessing geologic

  2. An example of liquefaction-induced interdune sedimentation from the early Jurassic Navajo Sandstone, USA

    NASA Astrophysics Data System (ADS)

    Bryant, Gerald; Monegato, Giovanni; Miall, Andrew

    2013-11-01

    Extensive outcrops of Navajo Sandstone in the southwestern United States expose eolian dune deposits that are subdivided in a complex array of foresets and bounding surfaces. In the Glen Canyon region, and other places, this architecture is frequently disrupted by large-scale, soft-sediment deformation features. These features have been attributed to episodic liquefaction events that affected saturated sand below the level of the interdune surface. Though erosional truncation of deformation features indicates that liquefaction often occurred in the uppermost levels of Navajo dune deposits, very few paleotopographic disruptions due to subsurface deformation have been documented. Navajo Sandstone outcrops in West Canyon, Utah, provide unusually comprehensive exposure of architectural details linking large-scale deformation features and associated interdune deposits, enabling a well constrained appraisal of their genesis. At this location, a 23 m succession of sandstone, mudstone, carbonate, and chert deposits overlies a zone of deformation that extends, laterally, for hundreds of meters. This horizontally stratified lens occupies an abrupt synform along a bounding surface between successive crossbeds that otherwise appears as a featureless, sub-horizontal plane. Large-scale foresets below this bounding surface oversteepen at the margins of the synform and grade downdip into contorted stratification and structureless expanses. The authors propose that liquefaction in the Jurassic erg caused localized subsidence of a minor portion of a dry interdune surface to a position several meters below the contemporary water table. A succession of hyperpycnal sand flows, lacustrine evaporites, and eolian sheet and dune deposits filled this depression prior to the advance of large dunes across the site. The process/response dynamics evident in this outcrop suggest that deformation may have exercised significant, non-systematic control over depositional architectures in areas of

  3. Porosity and grain size controls on compaction band formation in Jurassic Navajo Sandstone

    NASA Astrophysics Data System (ADS)

    Schultz, Richard A.; Okubo, Chris H.; Fossen, Haakon

    2010-11-01

    Determining the rock properties that permit or impede the growth of compaction bands in sedimentary sequences is a critical problem of importance to studies of strain localization and characterization of subsurface geologic reservoirs. We determine the porosity and average grain size of a sequence of stratigraphic layers of Navajo Sandstone that are then used in a critical state model to infer plastic yield envelopes for the layers. Pure compaction bands are formed in layers having the largest average grain sizes (0.42-0.45 mm) and porosities (28%), and correspondingly the smallest values of critical pressure (˜22 MPa) in the sequence. The results suggest that compaction bands formed in these layers after burial to ˜1.5 km depth in association with thrust faulting beneath the nearby East Kaibab monocline, and that hardening of the yield caps accompanied compactional deformation of the layers.

  4. Contrasting styles of large-scale displacement of unconsolidated sand: examples from the early Jurassic Navajo Sandstone on the Colorado Plateau, USA

    NASA Astrophysics Data System (ADS)

    Bryant, Gerald

    2015-04-01

    Large-scale soft-sediment deformation features in the Navajo Sandstone have been a topic of interest for nearly 40 years, ever since they were first explored as a criterion for discriminating between marine and continental processes in the depositional environment. For much of this time, evidence for large-scale sediment displacements was commonly attributed to processes of mass wasting. That is, gravity-driven movements of surficial sand. These slope failures were attributed to the inherent susceptibility of dune sand responding to environmental triggers such as earthquakes, floods, impacts, and the differential loading associated with dune topography. During the last decade, a new wave of research is focusing on the event significance of deformation features in more detail, revealing a broad diversity of large-scale deformation morphologies. This research has led to a better appreciation of subsurface dynamics in the early Jurassic deformation events recorded in the Navajo Sandstone, including the important role of intrastratal sediment flow. This report documents two illustrative examples of large-scale sediment displacements represented in extensive outcrops of the Navajo Sandstone along the Utah/Arizona border. Architectural relationships in these outcrops provide definitive constraints that enable the recognition of a large-scale sediment outflow, at one location, and an equally large-scale subsurface flow at the other. At both sites, evidence for associated processes of liquefaction appear at depths of at least 40 m below the original depositional surface, which is nearly an order of magnitude greater than has commonly been reported from modern settings. The surficial, mass flow feature displays attributes that are consistent with much smaller-scale sediment eruptions (sand volcanoes) that are often documented from modern earthquake zones, including the development of hydraulic pressure from localized, subsurface liquefaction and the subsequent escape of

  5. Giant stromatolites and a supersurface in the Navajo Sandstone, Capitol Reef National Park, Utah

    NASA Astrophysics Data System (ADS)

    Eisenberg, Len

    2003-02-01

    At Capitol Reef National Park, Utah, 5-m-high stromatolites are present locally on interdune carbonate lenses in the Early Jurassic Navajo Sandstone. The stromatolites display both finely laminated and fenestral internal fabrics, and grew along south-facing interdune margins. These stromatolites formed during a high-water-table episode engendered by a dune-dammed paleodrainage in a stabilized Navajo erg. These stromatolites, and the thick interdune section associated with them, suggest a hiatus in erg accumulation and the presence of a super bounding surface.

  6. Downslope coarsening in aeolian grainflows of the Navajo Sandstone

    NASA Astrophysics Data System (ADS)

    Loope, David B.; Elder, James F.; Sweeney, Mark R.

    2012-07-01

    Downslope coarsening in grainflows has been observed on present-day dunes and generated in labs, but few previous studies have examined vertical sorting in ancient aeolian grainflows. We studied the grainflow strata of the Jurassic Navajo Sandstone in the southern Utah portion of its outcrop belt from Zion National Park (west) to Coyote Buttes and The Dive (east). At each study site, thick sets of grainflow-dominated cross-strata that were deposited by large transverse dunes comprise the bulk of the Navajo Sandstone. We studied three stratigraphic columns, one per site, composed almost exclusively of aeolian cross-strata. For each column, samples were obtained from one grainflow stratum in each consecutive set of the column, for a total of 139 samples from thirty-two sets of cross-strata. To investigate grading perpendicular to bedding within individual grainflows, we collected fourteen samples from four superimposed grainflow strata at The Dive. Samples were analyzed with a Malvern Mastersizer 2000 laser diffraction particle analyser. The median grain size of grainflow samples ranges from fine sand (164 μm) to coarse sand (617 μm). Using Folk and Ward criteria, samples are well-sorted to moderately-well-sorted. All but one of the twenty-eight sets showed at least slight downslope coarsening, but in general, downslope coarsening was not as well-developed or as consistent as that reported in laboratory subaqueous grainflows. Because coarse sand should be quickly sequestered within preserved cross-strata when bedforms climb, grain-size studies may help to test hypotheses for the stacking of sets of cross-strata.

  7. Biosignatures in Spheroidal Iron Oxide-Rich Concretions from the Navajo Sandstone

    NASA Astrophysics Data System (ADS)

    Spanbauer, T. L.; Kettler, R. M.; Loope, D. B.; Weber, K. A.

    2009-12-01

    Spheroidal concretions composed of an iron oxide-rich cemented outer rind and a weakly-cemented core of bleached (iron depleted) sandstone are abundant in the Jurassic Navajo Sandstone of the Colorado Plateau. The formation of the spheroidal concretions has been previously described as a result of advective mixing between Fe(II)-rich reducing fluids with oxidizing fluids resulting in the subsequent abiotic precipitation of Fe(III) oxides forming the spheroidal concretions. The role of microbial biomineralization has been suggested as a potential mechanism of various other iron oxide formations, such as banded iron formations and iron-manganese nodules. Here we describe a series of qualitative and quantitative observations within the spheroidal concretions from the Jurassic Navajo Sandstone consistent with prior microbial activity. Spheroidal concretions were collected from Spencer Flat, east of Escalante, in south-central Utah, sectioned, and treated with dilute hydrochloric acid and acetone to remove traces of inorganic and organic carbon (C) from the surface of the samples. Elemental analysis of the treated specimens revealed elevated C as well as nitrogen (N) content with respect to the interior of the concretion (Rind, C, 0.06%, N, 0.006%; Interior, C, 0.009%, N, 0.003%). Elevated C and N values in the rind suggest carbon-nitrogen rich compounds consistent with biomolecules. Field Emission Scanning Electron Microscopy (FE-SEM) confirmed the presence of C as well as N and S via electron backscattering analysis. Additionally, structures morphologically consistent with bacterial cells have been observed via FE-SEM in association with a matrix that coated sand grains within the iron oxide-rich rind. Together these data suggest that microorganisms were associated with the iron oxide-rich spheroidal concretions. Microbial iron oxidation has been demonstrated to be ubiquitous microbial metabolism and is facilitated by a diversity of microorganisms in terrestrial

  8. Blueberries on Earth and Mars: Correlations Between Concretions in Navajo Sandstone and Terra Meridiani on Mars.

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Milner, M. W.; Netoff, D.; Dohm, J.; Kalm, V.; Krinsley, D.; Sodhi, R. N.; Anderson, R. C.; Boccia, S.; Malloch, D.; Kapran, B.; Havics, A.

    2008-12-01

    Concretionary Fe-Mn-rich nodular authigenic constituents of Jurassic Navajo sandstone (moki marbles) bear a certain relationship to similar concretionary forms ('blueberries') observed on Mars. Their origin on Earth is considered to invoke variable redox conditions with underground fluids penetrating porous quartz-rich sandstone leading to precipitation of hematite and goethite-rich material from solution, generally forming around a central nucleus of fine particles of quartz and orthoclase, recently verified by XRD and SEM-EDS analyses. At the outer rim/inner nucleus boundary, bulbous lobes of fine-grained quartz often invade and fracture the outer rim armored matrix. The bulbous forms are interpreted to result from fluid explusion from the inner concretionary mass, a response to pressure changes accompanying overburden loading. Moki marbles, harder than enclosing rock, often weather out of in situ sandstone outcrops that form a surface lag deposit of varnished marbles that locally resemble desert pavement. The marbles appear morphologically similar to 'blueberries' identified on the martian surface in Terra Meridiani through the MER-1 Opportunity rover. On Earth, redox fluids responsible for the genesis of marbles may have emanated from deep in the crust (often influenced by magmatic processes). These fluids, cooling to ambient temperatures, may have played a role in the genesis of the cemented outer rim of the concretions. The low frequency of fungi filaments in the marbles, contrasts with a high occurrence in Fe-encrusted sands of the Navajo formation [1], indicating that microbial content is of secondary importance in marble genesis relative to the fluctuating influx of ambient groundwater. Nevertheless, the presence of filaments in terrestrial concretions hints at the possibility of discovering fossil/extant life on Mars, and thus should be considered as prime targets for future reconnaissance missions to Mars. 1] Mahaney, W.C., et al. (2004), Icarus, 171, 39-53.

  9. CO2-Driven Convection Produced the Vertical Distribution of Sandstone Colors and Iron Concretions in Navajo Sandstone at Zion National Park, Utah (USA)

    NASA Astrophysics Data System (ADS)

    Kettler, R. M.; Loope, D. B.

    2011-12-01

    Along cliff faces exposed in Zion National Park (SW Utah), the porous and permeable Navajo Sandstone (Jurassic) is 700 m thick, and is capped by impermeable mudrocks and evaporites of the Carmel Formation. Previous workers have documented an areally extensive color pattern that is easily visible across much of southwestern and south-central Utah: the uppermost Navajo Sandstone is nearly white, the middle third of the formation is pink, and the lowermost fraction is reddish brown. To the northwest of the park, however, the formation is uniformly red (likely its primary color; G.B. Nielsen et al., 2009). Spheroidal concretions with dense, iron-oxide-cemented rinds and iron-poor cores are abundant in the pink and brown sandstones. Rhomb-shaped clots of iron oxide cement that are pseudomorphous after siderite are present in the cores of the largest concretions. The color variations are evidence that iron was transported from the upper portion of the Navajo SS to the lower portion. The pseudomorphs are evidence that the concretions are the oxidized remains of siderite-cemented precursors. The vertical iron transport and the precipitation of siderite require similar vertical transport of reducing, CO2-rich formation waters through the Navajo Sandstone. We argue that this circulation was driven in part by groundwater convection beneath a CO2 accumulation that was trapped below the Navajo-Carmel contact. This circulation caused aqueous iron and aqueous carbonate to be displaced downward and to accumulate (in the form of siderite) in the lower Navajo Sandstone. There are numerous CO2 reservoirs in the Colorado Plateau region; the gas was derived mainly from mantle sources. We hypothesize that, in the late Tertiary, the Carmel Formation capped a broad, structurally high accumulation of CO2 and CH4 in the Navajo Sandstone. The CH4 bleached the upper portion of the sandstone, releasing Fe2+ into the formation water. CO2 dissolved in the water, thereby increasing its density

  10. Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization

    USGS Publications Warehouse

    Zhu, Chen; Veblen, D.R.; Blum, A.E.; Chipera, S.J.

    2006-01-01

    Naturally weathered feldspar surfaces in the Jurassic Navajo Sandstone at Black Mesa, Arizona, was characterized with high-resolution transmission and analytical electron microscope (HRTEM-AEM) and field emission gun scanning electron microscope (FEG-SEM). Here, we report the first HRTEM observation of a 10-nm thick amorphous layer on naturally weathered K-feldspar in currently slightly alkaline groundwater. The amorphous layer is probably deficient in K and enriched in Si. In addition to the amorphous layer, the feldspar surfaces are also partially coated with tightly adhered kaolin platelets. Outside of the kaolin coatings, feldspar grains are covered with a continuous 3-5 ??m thick layer of authigenic smectite, which also coats quartz and other sediment grains. Authigenic K-feldspar overgrowth and etch pits were also found on feldspar grains. These characteristics of the aged feldspar surfaces accentuate the differences in reactivity between the freshly ground feldspar powders used in laboratory experiments and feldspar grains in natural systems, and may partially contribute to the commonly observed apparent laboratory-field dissolution rate discrepancy. At Black Mesa, feldspars in the Navajo Sandstone are dissolving at ???105 times slower than laboratory rate at comparable temperature and pH under far from equilibrium condition. The tightly adhered kaolin platelets reduce the feldspar reactive surface area, and the authigenic K-feldspar overgrowth reduces the feldspar reactivity. However, the continuous smectite coating layer does not appear to constitute a diffusion barrier. The exact role of the amorphous layer on feldspar dissolution kinetics depends on the origin of the layer (leached layer versus re-precipitated silica), which is uncertain at present. However, the nanometer thin layer can be detected only with HRTEM, and thus our study raises the possibility of its wide occurrence in geological systems. Rate laws and proposed mechanisms should consider the

  11. Characterization of Navajo Sandstone concretions: Mars comparison and criteria for distinguishing diagenetic origins

    NASA Astrophysics Data System (ADS)

    Potter, Sally L.; Chan, Marjorie A.; Petersen, Erich U.; Dyar, M. Darby; Sklute, Elizabeth

    2011-01-01

    The eolian Jurassic Navajo Sandstone spheroidal hydrous ferric oxide (HFO) concretions are divided into two size classes: macro-concretions of > 5 mm diameter and micro-concretions of < 5 mm diameter. Three internal structural end-members of macro-concretions are described as rind, layered, and solid. Two end-members of micro-concretions are rind and solid. Chemical and mineralogical gradients (μm- to mm-scale) are identified with QEMSCAN (Quantitative Elemental Mineralogy using a SCANning electron microscope) and visible to near infrared (VNIR) reflectance spectroscopy. Three HFO phases are identified using VNIR reflectance spectroscopy. An amorphous HFO phase is typically located in the rinds. Goethite is present along interior edges of rinds and throughout the interiors of layered and solid concretions. Hematite is present in the centers of rind concretions. A synthesis of petrographic, mineralogical and chemical analyses suggests that concretions grow pervasively (as opposed to radially expanding). Our model proposes that concretions precipitate initially as an amorphous HFO that sets the radius and retains some original porosity. Subsequent precipitation fills remaining pore space with younger mineral phases. Inward digitate cement crystal growth corroborates concretion growth from a set radius toward the centers. Internal structure is modified during late stage precipitation that diffuses reactants through semi-permeable rinds and overprints the interiors with younger cements. Physical characterization of textures and minerals provides diagnostic criteria for understanding how similar concretions ("blueberries") form in Meridiani Planum, Mars. The analogous Navajo Sandstone concretions show similar characteristics of in situ self-organized spacing, spheroidal geometries, internal structures, conjoined forms, and precursor HFO phases that dehydrate to goethite or hematite. These characteristics indicate a common origin via groundwater diagenesis.

  12. Naturally weathered feldspar surfaces in the Navajo Sandstone aquifer, Black Mesa, Arizona: Electron microscopic characterization

    NASA Astrophysics Data System (ADS)

    Zhu, Chen; Veblen, David R.; Blum, Alex E.; Chipera, Stephen J.

    2006-09-01

    Naturally weathered feldspar surfaces in the Jurassic Navajo Sandstone at Black Mesa, Arizona, was characterized with high-resolution transmission and analytical electron microscope (HRTEM-AEM) and field emission gun scanning electron microscope (FEG-SEM). Here, we report the first HRTEM observation of a 10-nm thick amorphous layer on naturally weathered K-feldspar in currently slightly alkaline groundwater. The amorphous layer is probably deficient in K and enriched in Si. In addition to the amorphous layer, the feldspar surfaces are also partially coated with tightly adhered kaolin platelets. Outside of the kaolin coatings, feldspar grains are covered with a continuous 3-5 μm thick layer of authigenic smectite, which also coats quartz and other sediment grains. Authigenic K-feldspar overgrowth and etch pits were also found on feldspar grains. These characteristics of the aged feldspar surfaces accentuate the differences in reactivity between the freshly ground feldspar powders used in laboratory experiments and feldspar grains in natural systems, and may partially contribute to the commonly observed apparent laboratory-field dissolution rate discrepancy. At Black Mesa, feldspars in the Navajo Sandstone are dissolving at ˜10 5 times slower than laboratory rate at comparable temperature and pH under far from equilibrium condition. The tightly adhered kaolin platelets reduce the feldspar reactive surface area, and the authigenic K-feldspar overgrowth reduces the feldspar reactivity. However, the continuous smectite coating layer does not appear to constitute a diffusion barrier. The exact role of the amorphous layer on feldspar dissolution kinetics depends on the origin of the layer (leached layer versus re-precipitated silica), which is uncertain at present. However, the nanometer thin layer can be detected only with HRTEM, and thus our study raises the possibility of its wide occurrence in geological systems. Rate laws and proposed mechanisms should consider the

  13. Tracing paleofluid circulations using iron isotopes: A study of hematite and goethite concretions from the Navajo Sandstone (Utah, USA)

    NASA Astrophysics Data System (ADS)

    Busigny, Vincent; Dauphas, Nicolas

    2007-02-01

    Iron concentrations and isotopic compositions were measured in spherical hematite and goethite concretions, together with associated red (Fe-oxide coated) and white (bleached) sandstones from the Jurassic Navajo formation, Utah (USA). Earlier studies showed that, in the Navajo Sandstone, reducing fluids (presumably rich in hydrocarbons) mobilized Fe present as Fe-oxide coatings on detrital quartz grains. Dissolved Fe then precipitated as spherical concretions by interaction with oxidizing groundwater. Despite being depleted in Fe by ˜ 50%, the bleached sandstones have Fe isotopic compositions similar to adjacent red sandstones (˜ 0‰/amu relative to IRMM-014). This shows that dissolution of Fe-oxide did not produce significant isotope fractionation, in agreement with previous experimental studies of abiotic Fe-oxide dissolution. In contrast, the concretions are depleted in the heavy isotopes of iron by - 0.07 to - 0.68‰/amu. This is opposite to the expected fractionation for partial Fe oxidation, which tends to enrich the precipitate in the heavy isotopes. Several scenarios are considered for explaining the measured Fe isotopic compositions. Although diffusion might be an important process in controlling the growth of spherical concretions, the associated isotopic fractionation is negligible compared to the observed variations. Kinetic isotope fractionation during precipitation can be ruled out as well because no isotopic zonation is seen within indurated concretions and Fe isotope evidence supports the occurrence of dissolution-reprecipitation reactions consistent with equilibrium growth conditions. The Fe isotopic compositions of the concretions are best explained by evolution of the fluid composition through precipitation and/or adsorption of isotopically heavy Fe during fluid flow through the sandstone. This scenario is supported by a regional trend in the isotopic composition of Fe, showing that this element was transported in fluids over several

  14. Aquifer tests of the Navajo sandstone near Caineville, Wayne County, Utah

    USGS Publications Warehouse

    Hood, J.W.; Danielson, T.W.

    1979-01-01

    Ground water in the Navajo Sandstone near Caineville, Wayne County, Utah, was studied during 1975-77 as part of an investigation of water in bedrock in the lower Dirty Devil River basin area. The purpose of the study near Caineville was to determine the water-bearing properties of the Navajo by utilizing data obtained mainly during test drilling and aquifer testing by the Intermountain Power Project.

  15. Eolian sabkha sandstones in the Nugget Sandstone (Jurassic), Vernal area, Utah

    SciTech Connect

    Schenk, C.J.; Peterson, F. )

    1991-06-01

    The Jurassic Nugget Sandstone in the Vernal, Utah, area is characterized by thick (up to 25 m) sets of cross-stratified eolian dune sandstone separated by either erosional planar bounding surfaces or thin (mostly < 3 m) sandstones interpreted as sabkha sandstones. Structures in Nugget sabkha sandstones are predominantly wavy or irregular bedding and thin, remnant sets of dune cross-strata consisting of eolian ripple and avalanche strata. The types of sedimentary structures and erosional features in Nugget sabkha sandstones indicate a close relationship between sand deposition and erosion and fluctuations in the local water table. Thin, remnant eolian dune sets are common in Nugget sabkha sandstones. The remnant sets form when dunes migrating across a sabkha are partially wetted as the water table rises slightly (on a scale of tens of centimeters); the lower part of the dune with wetted sand remains on the sabkha as the rest of the dune continues to migrate. Typically, ripple strata of the dune apron and the toes of avalanche strata are preserved in dune remnants. The avalanche strata, being slightly coarser grained, are preferentially deflated, leaving microtopography. This topography is commonly filled in with ripple strata that form as dry sand again blows across the sabkha. Stacked sets of remnant dunes separated by erosional surfaces illustrate the control of sand deposition on eolian sabkhas by the local water table.

  16. Mineralogical Characterization of Navajo Sandstone Iron Oxide Concretions Using QEMSCAN and Reflectance Spectroscopy; Analogue for Martian Diagenetic Processes

    NASA Astrophysics Data System (ADS)

    Potter, S. L.; Chan, M. A.; Petersen, E. U.

    2008-03-01

    The Navajo Sandstone concretions were evaluated to detect mineralogical changes and chemical gradients. Sequential relationships suggest an evolution of phases of cements. The Mars "blueberries" may have a similar evolution of cements.

  17. 3D visualization of liquefaction-induced dune collapse in the Navajo Sandstone, Utah, USA

    NASA Astrophysics Data System (ADS)

    Ford, Colby; Nick, Kevin; Bryant, Gerald

    2015-04-01

    The eolian Navajo Sandstone outcrop on the Canyon Overlook Trail in Zion National Park in Southern Utah is dissected by modern erosion in a way which reveals a great deal of the three-dimensional architecture of a major soft-sediment deformation event. The feature is bounded below by a well-developed interdune complex made up of two superimposed carbonate lenses, above by an irregular truncational surface, and incorporates 3 - 10 m of sandstone over an approximately 2 km area. The material above the deformed interval is undeformed cross-bedded sandstone, with crossbeds downlapping onto the surface of truncation. The stratigraphic confinement of deformation and the irregularity of the upper bounding surface suggests a deformation process which created topography, which was in turn covered by the next upwind dune before it could be eroded flat. The deformed material itself is laterally segmented by a stacked succession of shear surfaces, which all strike approximately perpendicular to the paleo-wind direction and dip at decreasing angles in the down paleo-wind direction. These factors point to the collapse of a major dune into the downwind interdune area, likely initiated by liquefaction in the interdune complex. The foundering of the dune's toe into the liquefied area created a powerful lateral stress field which did not extend significantly into the subsurface. The dune collapse process has been used in the past to describe other soft-sediment deformation features in the Navajo Sandstone, but this site provides a wealth of physical details which were not previously associated with dune collapse. Shear surfaces originate in the interdune deposit as slip between laminae, then the cohesive muds provided support as they were thrust upward to angles of up to 50 degrees. The margins of the site also contain important paleoenvironmental indicators. Dinosaur tracks are exposed both at the extreme upwind and downwind margins of the interdune deposit in and slightly above

  18. Frisco City sandstone: Upper Jurassic play in southern Alabama

    SciTech Connect

    Montgomery, S.L.; Baria, L.R.; Handford, C.R.

    1997-10-01

    The Frisco City sandstone play in southern Alabama is an example of hydrocarbon entrapment on the flanks of basement erosional features, with principal reservoirs occurring in proximal alluvial-fan to marine shoreface facies. Productive fields are developed on four-way closures of complex geometry, with reservoir sandstones showing maximum thickness along the margins of basement highs that are roughly 1.3-5.18 km{sup 2} in size and have 136-151 m of relief. Detailed analysis of sandstone facies indicates a downdip progression from alluvial-fan through wadi, eolian, beach, tidal-flat, and shoreface deposits. A sequence stratigraphic model based on identification of backstepping strata representing successive transgressive events is useful in predicting maximum reservoir occurrence in the vicinity of inselbergs. Reservoir quality in productive sandstones is high, with porosities ranging from 13 to 27% and permeabilities of 50 md to 5 d. Hydrocarbon occurrence is related to the distribution of high-quality source rock in the Smackover Formation and to maturation history.

  19. Net-Infiltration Map of the Navajo Sandstone Outcrop Area in Western Washington County, Utah

    USGS Publications Warehouse

    Heilweil, Victor M.; McKinney, Tim S.

    2007-01-01

    As populations grow in the arid southwestern United States and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration and recharge becomes critically important for inventorying ground-water resources and mapping contamination vulnerability. A Geographic Information System (GIS)-based model utilizing readily available soils, topographic, precipitation, and outcrop data has been developed for predicting net infiltration to exposed and soil-covered areas of the Navajo Sandstone outcrop of southwestern Utah. The Navajo Sandstone is an important regional bedrock aquifer. The GIS model determines the net-infiltration percentage of precipitation by using an empirical equation. This relation is derived from least squares linear regression between three surficial parameters (soil coarseness, topographic slope, and downgradient distance from outcrop) and the percentage of estimated net infiltration based on environmental tracer data from excavations and boreholes at Sand Hollow Reservoir in the southeastern part of the study area. Processed GIS raster layers are applied as parameters in the empirical equation for determining net infiltration for soil-covered areas as a percentage of precipitation. This net-infiltration percentage is multiplied by average annual Parameter-elevation Regressions on Independent Slopes Model (PRISM) precipitation data to obtain an infiltration rate for each model cell. Additionally, net infiltration on exposed outcrop areas is set to 10 percent of precipitation on the basis of borehole net-infiltration estimates. Soils and outcrop net-infiltration rates are merged to form a final map. Areas of low, medium, and high potential for ground-water recharge have been identified, and estimates of net infiltration range from 0.1 to 66 millimeters per year (mm/yr). Estimated net-infiltration rates of less than 10 mm/yr are considered low, rates of 10 to 50 mm

  20. Lower Jurassic Navaho-Aztec-Equivalent Sandstones in southern Arizona and their paleogeographic significance

    SciTech Connect

    Bilodeau, W.L.; Keith, S.B.

    1986-06-01

    Thick sequences of Lower Jurassic rhyolitic and andesitic volcanic rocks in several mountain ranges of southern Arizona contain interbedded quartzarenites. Locally up to 250 m thick, these sandstone lenses, composed of well-sorted and well-rounded quartz grains, commonly contain large-scale cross-stratification and are considered to be eolian sand deposits. The eolian sands were blown up against the continental side of the Early Jurassic volcanic arc that trended northwest-southeast across the southwestern margin of the North American continent and/or plate at that time. Paleocurrent data suggest southerly eolian transport of the sands from the Colorado Plateau area. Correlation of these sandstones with the Lower Jurassic Navaho and Aztec Sandstones is indicated by the paleocurrent data as well as radiometric dating of the interbedded volcanics. Eolian sand transport southward across central Arizona in the Early Jurassic indicates that the Mogollon highlands either did not then exist, or were merely low, discontinuous inselbergs on a broad back-arc ramp, more appropriately called the Mogollon slope.

  1. Haynesville sandstone reservoirs in the Updip Jurassic trend of Alabama

    SciTech Connect

    Kugler, R.L.; Mink, R.M.

    1994-09-01

    Subsequent to the 1986 drilling of the 1 Carolyn McCollough Unit 1-13 well, which initiated production from the Frisco City sand of the Haynesville Formation in Monroe County, Alabama, seven Haynesville fields have been established in Covington, Escambia, and Monroe counties. Initial flow rates of several hundred BOPD are typical for wells in these fields, and maximum rates exceed 2000 BOPD in North Frisco City field. As of August 1993, these fields produced more than 3,400,000 bbl of oil and 4,000,000 mcf of gas from depths of 12,000 to 13,000 ft. Haynesville sandstone reservoirs are concentrated in two distinct areas: (1) an eastern area (Hickory Branch, North Rome, and West Falco fields; API oil gravity = 40{degrees}) in the Conecuh embayment and (2) a western area (Frisco City, North Frisco City, southeast Frisco City, and Megargel fields; API oil gravity = 58-59{degrees}) on the Conecuh ridge complex. Eastern fields are productive from Haynesville sandstone, which is not continuous with the two distinct, productive sandstone bodies in western fields, the Frisco City sand and the Megargel sand. Hydrocarbon traps are structural or combination traps associated with basement paleohighs. Reservoir bodies generally consist of conglomerate (igneous clasts in western fields; limestone clasts in eastern fields), sandstone (subarkose-arkose), and shale (some of which is red) in stacked fining-upward sequences. Shale at the tops of these sequences is bioturbated. These marine strata were deposited in shoal-water braid-delta fronts. Petrophysical properties differ between the two areas. Maximum and average permeability in western fields (k{sub max} = 2000 md; k{sub ave} = 850-1800 md) is an order of magnitude higher than in eastern fields. The distribution of diagenetic components, including a variety of carbonate minerals, evaporate minerals (anhydrite and halite in western fields), and carbonate-replaced pseudomatrix, commonly is related to depositional architecture.

  2. Temperatures of quartz cementation in Jurassic sandstones from the Norwegian continental shelf -- evidence from fluid inclusions

    SciTech Connect

    Walderhaug, O. )

    1994-04-01

    Recent studies of fluid inclusions in quartz overgrowths have shown quartz cementation to have taken place at temperatures within the range 60--145 C in several sandstones from the North Sea and offshore mid-Norway (Malley et al. 1986; Konnerup-Madsen and Dypvik 1988; Burley et al. 1989; Walderhaug 1990; Ehrenberg 1990; Saigal et al. 1992; Nedkvitne et al. 1993). This study aims at determining whether these results are typical for quartz cementation of sandstones by presenting homogenization temperatures for 274 aqueous and 366 hydrocarbon inclusions in quartz overgrowths from Jurassic reservoir sandstones on the Norwegian continental shelf, and by reviewing previously published fluid-inclusion data. Possible explanations for different ranges of homogenization temperatures in different sandstones are also discussed, and possible sources of quartz cement and the effect of hydrocarbon emplacement on quartz cementation are considered.

  3. Groundwater-silicates Reaction Kinetics in the Navajo Sandstone Aquifer, Black Mesa, Arizona (Invited)

    NASA Astrophysics Data System (ADS)

    Zhu, C.

    2009-12-01

    Despite numerous studies of soil profiles and watersheds for critical zone processes, the studies of reaction kinetics in groundwater systems are relatively a few. Yet, aquifers are major sites for water-rock interaction, and a significant segment of the hydrological cycle and global elemental cycling. In this presentation, I will show a multi-discipline study of the Navajo sandstone aquifer at Black Mesa, Arizona. The aeolian sandstone represents some simplest lithology, and the study area has unusually abundant hydrologic, geochemical, isotopic, and paleoclimate data. Solute fluxes along flow paths are supplemented by travel time bounded by 14C and excess 4-He data, from which orders of magnitude estimates of the in situ silicate dissolution rates were calculated. These rates show two to five orders of magnitude slower than those from laboratory experiments at comparable temperature and pH and at far from equilibrium conditions, and are much slower than those derived from studies of soils and watersheds. Data from some new analytical and microscopic methods show that the reaction kinetics are complex. Stable Si isotopes of dissolved Si in groundwater along a 100 km flow path show 2 per mil variation and as low as -1.42‰, representing the most negative dissolved Si isotope composition so far found for natural waters. Near atomic scale transmission electron microscopy show a thin (~ 10 nm) amorphous layer is present on naturally weathered K-feldspars in the aquifer, which requires re-consideration of the details of surface reaction controlled mechanism. However, the new hypothesis of strongly coupled dissolution and precipitation reactions that we have been advancing in recent years appear to be able to explain part of the well-known apparent field-lab discrepancy. The slow precipitation of secondary minerals raised the groundwater saturation state with respect to feldspars to close to equilibrium, and thus retard the feldspar dissolution rates. Our recent

  4. Oxfordian-Kimmeridgian (Late Jurassic) reservoir sandstones in the Witch Ground Graben, U. K. North Sea

    SciTech Connect

    Harker, S.D. Ltd., Aberdeen ); Mantel, K.A. ); Morton, D.J. ); Riley, L.A. )

    1991-03-01

    Oil-bearing Late Jurassic Oxfordian-Kimmeridgian sandstones of the Sgiath and Piper formations are of major economic importance in the Witch Ground Graben. They form the reservoirs in Scott, which in 1993 will be the largest producing North Sea oil field to come on stream for more than a decade. Together with Scott, the Piper, Saltire, Tartan, Highlander, Petronella, Rob Roy, and Ivanhoe fields contained almost 2 Bbbl of recoverable reserves in these formations. The Sgiath and Piper represent two phases of Late Jurassic transgression and regression, initially represented by paralic deposited sand culminating in a wave-dominated delta sequence. The history of the Sgiath and Piper formations is reviewed and lithostratigraphic and biostratigraphic correlations presented to illustrate the distribution of the reservoir sandstones.

  5. Acoustic Emission and Ultrasonic Characterization of Jurassic Navajo Formation Deformation During Axisymmetric Compression Testing

    NASA Astrophysics Data System (ADS)

    Rinehart, A. J.; Dewers, T. A.; Holcomb, D. J.; Broome, S. T.

    2011-12-01

    Linking continuum-scale and microscale brittle damage in rock remains a challenge impacting CO2 sequestration, secondary recovery, structural monitoring, and other geotechnical engineering applications. We examine if the mode of micromechanical failure scales directly up to continuum-scale damage-induced velocity anisotropy. Axisymmetric drained lab-dry compression experiments are performed on facies of moderately cemented finely laminated quartz arenite from the Jurassic Navajo Formation, a target reservoir rock for CO2 sequestration in Utah. The tests are 1 unconfined uniaxial compression test, 1 hydrostatic compression test, and 3 triaxial compression tests. Microscale damage is monitored using acoustic emissions (AE) and continuum scale damage is monitored with ultrasonic velocity scans. During the non-hydrostatic tests, three to five unload loops are performed pre-failure, with one unload loop performed post-failure. While stresses are increasing, AEs are monitored continuously using 1.6-mm diameter, 0.5-mm thick PZT-5A pins attached circumferentially around the cylindrical sample, and with 6-mm diameter, 2-mm thick PZT-5A discs at the ends of the sample. Before and after each unload loop, the test is paused and the AE transducers sequentially emit an ultrasonic pulse to measure wave speeds. The resulting elastic wave is detected by the other AE transducers. Post-test, the changing anisotropic velocity structure of the rock during compression and failure is compared to the locations, frequency, and relative moment tensors of the AEs measured between ultrasonic scans. Pre- and post-test visual and x-ray CT scan observations of the sample are compared to the acoustic metrics. These tiered observations of rock damage will further elucidate the scaling of microscale brittle failure to the continuum-scale This work was supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of

  6. Strength and failure characteristics of Jurassic Red-Bed sandstone under cyclic wetting-drying conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenhua; Jiang, Qinghui; Zhou, Chuangbing; Liu, Xinting

    2014-08-01

    Due to cyclic fluctuations of reservoir water levels, bank slopes in drawdown areas are subjected to wetting-drying cycles. In order to reasonably evaluate the stabilities of sandstone slopes in the drawdown area of the Three Gorges Reservoir, it is a primary premise to obtain the strength and failure characteristics of the sandstones undergoing wetting-drying cycles. In this paper, the conventional triaxial compression tests, ultrasonic velocity and porosity measurements and microstructural observations were conducted on Jurassic Red-Bed sandstone (JRS) specimens undergoing wetting-drying cycles. The results from the triaxial experiments indicate that the peak strengths of the JRS are dramatically reduced after the first wetting-drying cycle, and then remain approximately constant with increasing number of wetting-drying cycles. The failure modes of the JRS samples undergoing different wetting-drying cycles are all brittle failures under low confining pressures ( ≤ 15 MPa). The decrease in P-wave velocity and increase in porosity with increasing number of wetting-drying cycles reveals the raise of damage level of the sandstone specimens, which is the main reason for the decline of peak strength. Detailed microstructural analysis has shown obvious argillization phenomena after undergoing wetting-drying cycles, which weakens the cements between grains in the sandstone and increases the damage of the sandstone.

  7. Diagenetic history of fluvial and lacustrine sandstones of the Hartford Basin (Triassic Jurassic), Newark Supergroup, USA

    NASA Astrophysics Data System (ADS)

    Wolela, A. M.; Gierlowski-Kordesch, E. H.

    2007-04-01

    The early introduction of clays into continental sandstones has been attributed to mechanical infiltration by percolation of clay-rich surface waters into grain framework or cutans formed from pedogenic processes. The discovery of pedogenic mud aggregates as traction-load mud in ancient fluvial deposits suggests that permeability and porosity of terrigenous sandstones can be influenced at deposition and control early diagenetic patterns. This study compares diagenesis in fluvial (subaerially exposed) sandstones with lacustrine (subaqueous) sandstones in a Triassic-Jurassic continental rift basin (Hartford Basin, Newark Supergroup). Diversity of diagenetic minerals and sequence of diagenetic alteration can be directly related to depositional environment. The fluvial sandstones in the New Haven Arkose, East Berlin Formation, and Shuttle Meadow Formation of the Hartford Basin are dominated by concretionary calcite and early calcite cement, infiltrated clays (illite-smectite), pedogenic mud aggregates (smectite and illite-smectite), grain coating clays (illite/hematite, illite-chlorite/hematite), quartz overgrowths, late stage carbonate cements (calcite, ferroan calcite), pore-filling clays (illite, kaolinite with minor amounts of smectite, smectite-chlorite, illite-smectite) and hematite. However, pedogenic processes in these fluvial sandstones retarded the development of quartz and feldspar overgrowths, and carbonate authigenesis, as well as the quality of diagenetically enhanced porosity. Dark gray-black lacustrine (subaqueous) sandstones and mudrocks in the East Berlin and Shuttle Meadow Formations are dominated by pyrite, concretionary dolomite and early dolomite cement, radial grain coating clays (smectite-chlorite, illite-smectite), late stage carbonate cements (dolomite, ferroan dolomite, ankerite), albite and pore-filling clays (smectite-chlorite, illite-smectite, illite-chlorite). Clay minerals exist as detrital, mechanically infiltrated, and neoformed clay

  8. Petrology and diagenesis of Upper Triassic and Lower Jurassic graben-fill sandstones of Jameson land basin, central east Greenland

    SciTech Connect

    Davee, K.W.; Mansfield, C.F.

    1986-05-01

    Sands of the Upper Triassic-Lower Jurassic Kap Stewart and Lower Jurassic Neill Klinter Formations were deposited during the early development of a major Jurassic rift basin. Depositional environments have been interpreted as alluvial fan, fluvial, and deltaic for the Kap Stewart, and as tidal estuary for the Neill Klinter. Most of these sandstones are fine to medium-grained quartz and subarkosic wackestones. Clay matrix is abundant and comprises mostly diagenetic kaolinite, illite, and complex clay mixtures derived from the breakdown of labile framework grains, especially plagioclase and biotite. Early emplacement of carbonate cement in some sandstones prevented development of diagenetic clay matrix. The carbonate cement is poikilotopic and constitutes up to 30% of some samples. The current high level of maturity indicated by the quartz-feldspar-lithic composition for these sandstones results from selective diagenetic decomposition of labile grains. The original, more feldspathic compositions reflect less maturity and an earlier stage of basin fill than the Middle Jurassic, high-porosity arenites, which also contain abundant quartz and up to 25% feldspar. Because of Upper Triassic and Lower Jurassic sands were deposited in continental and low-energy marine environments, they likely underwent greater in-situ alteration but less winnowing of labile grains than the overlying Middle Jurassic sands deposited in higher energy marine settings.

  9. Diagenetic quartzarenite and destruction of secondary porosity: An example from the Middle Jurassic Brent sandstone of northwest Europe

    SciTech Connect

    Harris, N.B. )

    1989-04-01

    Significant amounts of feldspar have been dissolved from Middle Jurassic sandstone oil reservoirs in the North Sea (northwest Europe) during burial diagenesis Sandstones of the Middle Jurassic Brent Group become increasingly quartzose with increasing burial depth. At Statfjord field (2500 m depth), sandstones are arkose to subarkose; at Hutton field (3050 m depth), they are subarkose to quartzarenite, and at Lyell field (3500 m depth), sandstones are typically quartzarenite. In spite of extensive feldspar dissolution, the abundance of secondary porosity due to feldspar dissolution is similar for all fields, averaging 2.9% of the total rock volume. Thus, far more feldspar has been dissolved than is recorded as secondary porosity. The limit on preservation of secondary porosity may be largely the effect of the mechanical strength of the rock. An excessive number of large secondary pores lowers the rock strength below the point at which the rock can withstand overburden stress, thus causing collapse of some of the secondary pores.

  10. Diagenetic quartzarenite and destruction of secondary porosity: An example from the Middle Jurassic Brent sandstone of northwest Europe

    NASA Astrophysics Data System (ADS)

    Harris, Nicholas B.

    1989-04-01

    Significant amounts of feldspar have been dissolved from Middle Jurassic sandstone oil reservoirs in the North Sea (northwest Europe) during burial diagenesis. Sandstones of the Middle Jurassic Brent Group become increasingly quartzose with increasing burial depth. At Stafford field (2500 m depth), sandstones are arkose to subarkose; at Hutton field (3050 m depth), they are subarkose to quartzarenite; and at Lyell field (3500 m depth), sandstones are typically quartzarenite. In spite of extensive feldspar dissolution, the abundance of secondary porosity due to feldspar dissolution is similar for all fields, averaging 2.9% of the total rock volume. Thus, far more feldspar has been dissolved than is recorded as secondary porosity. The limit on preservation of secondary porosity may be largely the effect of the mechanical strength of the rock. An excessive number of large secondary pores lowers the rock strength below the point at which the rock can withstand overburden stress, thus causing collapse of some of the secondary pores.

  11. Relationship Between Petrographic Characteristics and the Engineering Properties of Jurassic Sandstones, Hamedan, Iran

    NASA Astrophysics Data System (ADS)

    Heidari, M.; Momeni, A. A.; Rafiei, B.; Khodabakhsh, S.; Torabi-Kaveh, M.

    2013-09-01

    To study the relationship between engineering properties and petrographic characteristics, 20 rock samples were collected from Jurassic sandstones in the Hamedan region, western Iran. The specimens were tested to determine uniaxial compressive strength, point load strength index, tangent modulus, porosity, and dry and saturated unit weights. Samples were also subjected to petrographic examination, which included the observation of 11 parameters and modal analysis. Based on the results of a statistical analysis, polynomial prediction equations were developed to estimate physical and mechanical properties from petrographic characteristics. The results show that textural characteristics are more important than mineral compositions for predicting engineering characteristics. The packing density, packing proximity and grain shape are the petrographic properties that significantly affect the engineering properties of samples. Multivariate linear regression analysis was performed, employing four steps comprising various combinations of petrographic characteristics for each engineering parameter. The optimal equation, along with the relevant combination of petrographic characteristics for estimating the engineering properties of the rock samples is proposed.

  12. Reconstruction of eolian sequences - a function of scale, Jurassic Page sandstone, Arizona

    SciTech Connect

    Kocurek, G.; Knight, J.; Havholm, K.

    1989-03-01

    Interpretation of sequences of ergs and bed forms that comprise an eolian unit is strongly dependent on the scale of mapping. A pentagon-shaped, three-dimensional outcrop of eolian Middle Jurassic Page sandstone near Page, Arizona, measuring 36 m high and nearly 1 km in perimeter, was mapped with the aid of an electronic tacheometer. The extent and orientation of bounding surfaces and sets of cross-strata were mapped in detail, foreset orientation were measured, and a general depiction was made of the lateral and vertical distribution of stratification types within sets and of features associated with the surfaces. The level of mapping is at a middle scale with respect to architectural elements and proved adequate for an interpretation of most bed forms in terms of shape (two or three dimensions, sinuosity, symmetry, and crestline-phase relationships), size (height and width), aerodynamics (overall primary and secondary airflow patterns), and migration behavior (degree of climb and recognition of cyclicity). These interpretations allow the determination of bed-form hierarchy (simple dunes or draas) and of the bed-form type according to the descriptive (crescentic, linear) and dynamic (transverse, oblique, longitudinal) classifications. In conjunction with this level of mapping, large-scale or regional mapping was used in order to identify distinct, stacked, dune-field, and erg deposits that comprise the Page sandstone. Local mapping of the out-crop at a fine scale was necessary for refined interpretation of cyclicity, bed-form size, migration rate, and airflow pattern.

  13. Three-dimensional analysis of eolian systems in Jurassic Wingate sandstone

    SciTech Connect

    Nation, M.J.; Blakey, R.C.

    1989-03-01

    Regional bounding surfaces in ancient eolian sequences aid in establishing lateral profiles not previously obtainable using standard stratigraphic methods. Correlation of detailed measured sections permits three-dimensional analysis of erg dynamics in the Jurassic Wingate Sandstone on the Colorado Plateau. Four periods of erg development marked by contrasting styles of eolian architecture are documented in the Salt Anticline region (in ascending stratigraphic order): (1) discontinuous sand sheets, isolated dunes, and aqueous environments; (2) large compound dunes with decreasing amounts of dune margin material; (3) compound dunes and draas alternating with locally thick sandsheet deposits; and (4) widespread dunes and draas prior to erosion by Kayenta fluvial systems. Regional bounding surface characteristics reflect different mechanisms for erg stabilization, including deflation to the water table, climate change, and negative net sand budget. Lateral reconstruction and correlation of erg sequences indicate significant intrabasinal paleogeographic and tectonic controls on eolian systems. Localities removed from the Salt Anticline region contain much larger compound draa deposits and lack extensive accumulations of sand-sheet material. Regional comparison of these characteristics suggests that the salt uplifts modified eolian processes within the Wingate depositional basin. Existence of additional geographic variations not associated with salt tectonism is indicated by local accumulations of noneolian deposits in northeastern Arizona. The use of regional bounding surfaces to construct lateral profiles is a powerful method to establish three-dimensional models of eolian systems. Analysis of erg dynamics in other ancient eolian formations is possible utilizing the criteria documented in the Wingate Sandstone.

  14. The stratigraphy of Oxfordian-Kimmeridgian (Late Jurassic) reservoir sandstones in the Witch Ground Graben, United Kingdom North Sea

    SciTech Connect

    Harker, S.D. ); Mantel, K.A. ); Morton, D.J. ); Riley, L.A. )

    1993-10-01

    Oil-bearing Upper Jurassic Oxfordian-Kimmeridgian sandstones of the Sgiath and Piper formations are of major economic importance in the Witch Ground Gaben, United Kingdom North Sea. They form the reservoirs in 14 fields that originally contained 2 billion bbl of oil reserves, including Scott Field, which in 1993 will be the largest producing United Kingdom North Sea oil field to come on stream in more than a decade. The Sgiath and Piper formations represent Late Jurassic transgressive and regressive phases that began with paralic deposition and culminated in a wave-dominated delta system. These phases preceded the major grabel rifting episode (late Kimmeridgian to early Ryazanian) and deposition of the Kimmeridge Clay Formation, the principal source rock of the Witch Ground Graben oil fields. A threefold subdivision of the middle to upper Oxfordian Sgiath Formation is formally proposed, with Scott field well 15/21a-15 as the designated reference well. The basal Skene Member consists of thinly interbedded paralic carbonaceous shales, coals, and sandstones. This is overlain by transgressive marine shales of the Saltire Member. The upper-most Oxfordian Scott Member consists of shallow marine sandstones that prograded to the southwest. The contact of the Sgiath and Piper formations is a basinwide transgressive marine shale (I shale), which can act as an effective barrier to fluid communication between the Sgiath and Piper reservoir sandstones.

  15. Detrital Zircon Ages from Late Jurassic-Early Cretaceous Myrgovaam Basin Sandstones (Rauchua Trough), Western Chukotka, NE Russia

    NASA Astrophysics Data System (ADS)

    Miller, E. L.; Toro, J.; Gehrels, G.; Tuchkova, M.; Katkov, S.

    2004-12-01

    Late Jurassic to Early Cretaceous Myrgovaam Basin sediments (previously Rauchua Trough) are regionally significant because of the stratigraphic constraints they provide on the age and progression of deformation in the Chukotka fold belt, a possible along-strike continuation of the Alaskan Brooks Range fold-and-thrust belt. Existing descriptions of the structural and stratigraphic relations of Myrgovaam Basin sediments to underlying strata are contradictory. Some maps portray the basin fill as deposited unconformably over deformed Triassic and Jurassic strata of the Chukotka fold-belt. In other publications, the deposits are described as structurally detached and imbricated by N-verging thrust sheets (Baranov, 1996). Field studies reveal that underlying strata are tightly folded compared to overlying strata and that the contact is a structural discordance not an unconformity. More locally, we observed arkosic sandstones typical of the Myrgovaam Basin interbedded with underlying Late Jurassic strata or present as submarine channel deposits cut into older rocks, suggesting an original stratigraphic relationship. To reconcile these observations we suggest regional deformation post-dates deposition of Myrgovaam Basin deposits, and that the disharmony in deformational style between underlying thin-bedded Triassic sandstones and shales and (stratigraphically) overlying massive quartzites, is due to their different mechanical properties. Petrographic studies indicate that fine-grained Triassic-early Jurassic sandstones represent a distal recycled orogen source, while Myrgovaam Basin sandstones originated from a proximal orogenic source containing granitoid and crystalline basement rocks (microcline, biotite, muscovite and fragments of multiply deformed schist) and intermediate to felsic volcanic rocks. Laser Ablation ICPMS was used to date zircons (100 grains) from sandstones of the Myrgovaam Basin and compare them to those in Triassic sandstones (300 grains) and verify

  16. Kinematic implications of joint zones and isolated joints in the Navajo Sandstone at Zion National Park, Utah: Evidence for Cordilleran relaxation

    NASA Astrophysics Data System (ADS)

    Rogers, Christie M.; Myers, Douglas A.; Engelder, Terry

    2004-02-01

    At Zion National Park (ZNP) the landscape is a consequence of differential weathering of the Navajo Sandstone where closely spaced vertical joints constitute joint zones that erode to form regularly spaced (half kilometer) slot canyons striking 351°. Between these joint zones is a set of isolated joints striking 339°. Fracture interaction and horsetail/wing crack development indicate that the 339° striking joint set is younger than the 351° striking joint zones, despite the lateral extent of stress reduction shadows in the vicinity of the large-scale joint zones. In addition to an older, less pervasive, ˜020° joint set, this sequence of jointing records a counterclockwise rotation of the regional extension directed from WNW to WSW in the Navajo Sandstone at ZNP. ZNP is located at the western margin of the Colorado Plateau, ˜100 km east of the major normal faults of the northeastern central Basin and Range subprovince. Extension within the eastern central Basin and Range initiated during the Miocene and exhibited a WSW extension direction [, 1971; , 1988; , 2000]. The correlation between nearby Basin and Range extension and the extension direction for the 351° tending joint zones of ZNP is so close that the jointing at ZNP is interpreted as evidence for modest, yet pervasive Basin and Range extension in the western margin of the Colorado Plateau.

  17. Hydrocarbon-bearing sandstone in the Upper Jurassic Naknek Formation on the south shore of Kamishak Bay

    USGS Publications Warehouse

    Stanley, Richard G.; Herriott, Trystan M.; Helmold, Kenneth P.; Gillis, Robert J.; Lillis, Paul G.

    2013-01-01

    The presence of an active petroleum system in Kamishak Bay is demonstrated by an outcrop of hydrocarbon-bearing sandstone in the Upper Jurassic Naknek Formation near the south shore of the bay (fig. 1). The outcrop is about 140 km southwest of Homer on a small, unnamed island near the mouth of the Douglas River (fig. 17). The existence of this outcrop was kindly reported to us by Les Magoon (U.S. Geological Survey, emeritus), who also provided a topographic map showing its exact position. The outcrop was mentioned very briefly in publications by Magoon and others (1975, p. 19) and by Lyle and Morehouse (1977, p. E-1), but to our knowledge there are no detailed descriptions of this outcrop or its hydrocarbons in the published scientific literature.

  18. Haynesville sandstone reservoirs in the updip-Jurassic trend of Alabama

    SciTech Connect

    Kugler, R.L.; Mink, R.M.

    1994-12-31

    Since the 1986 drilling of the 1 Carolyn McCollough Unit 1-13 well, which initiated production from the Frisco City sandstone of the Haynesville Formation in Monroe County, Alabama, seven Haynesville fields have been established in Covington, Escambia, and Monroe Counties. Initial flow rates of several hundred BOPD are typical in wells in these fields, and maximum rates exceed 2,000 BOPD in North Frisco City field. As of August 1993, these fields had produced more than 3,400,000 bbl of oil and 4,000,000 Mcf of gas from depths of 12,000 to 13,000 ft. Haynesville sandstone reservoirs are concentrated in two distinct areas: (1) an eastern area (Hickory Branch, North Rome, and West Falco fields; API oil gravity = 40{degrees}) in the Conecuh embayment and (2) a western area (Frisco City, North Frisco City, southeast Frisco City, and Megargel fields, API oil gravity = 58-59{degrees}) on the Conecuh ridge complex. Eastern fields are productive from Haynesville sandstone, which is not continuous with the two distinct, productive sandstone bodies in western fields, the Frisco City sandstone and the Megargel sandstone. Hydrocarbon traps are structural or combination traps associated with basement paleohighs. Reservoir bodies generally consist of conglomerate (igneous clasts in western fields; limestone clasts in eastern fields), sandstone (subarkose-arkose), and shale (some of which is red) in stacked upward-fining sequences. Shale at the tops of these sequences is bioturbated. These marine strata were deposited in shoal-water braid-delta fronts. Maximum and average permeability in western fields (k{sub max} = 2,000 md; k{sub ave} = 850-1,800 md) is an order of magnitude higher than that in eastern fields. The distribution of diagenetic components, including a variety of carbonate minerals, evaporite minerals (anhydrite and halite in western fields), and carbonate-replaced pseudomatrix, commonly is related to depositional architecture.

  19. Role of halite in the evolution of sandstone porosity, upper Jurassic Norphlet Formation, Mississippi salt basin

    SciTech Connect

    Schenk, C.J.; Schmoker, J.W. )

    1993-09-01

    Analysis of petrographic point-count data, cement paragenesis, and scanning electron microscopy examination of pores has shown that poikilitic halite cement in sandstones of the Norphlet Formation in a core from Wayne County, Mississippi, formed following cementation by quartz, feldspar, dolomite, and anhydrite. Intergranular volume ranges from 26 to 42%, averaging 35%, indicating that an average of 10% of the rock volume was lost to compaction, and a further 10-15%, was lost to cementation prior to halite cementation, assuming a depositional porosity of about 45%. Most halite occurs as intergranular cement, but some halite is present as intragranular cement within framework feldspars and lithic fragments. Halite is easily removed from a sandstone during coring, slabbing, and thin-section preparation techniques that do not use oil-based fluids and muds, so the amount of porosity in these samples that is a product of artificial removal of halite is unknown. Although the present and former distribution of halite is poorly known, natural halite dissolution could have produced about 20% secondary porosity in the Norphlet Formation at depth in this part of the Mississippi Salt basin.

  20. Investigation of exfoliation joints in Navajo sandstone at the Zion National Park and in granite at the Yosemite National Park by tectonofractographic techniques

    SciTech Connect

    Bahat, D.; Grossenbacher, K.; Karasaki, K.

    1995-04-01

    Tectonofractographic techniques have been applied to the study of joint exfoliation in the Navajo sandstone at Zion National Park and in the granite at Yosemite National Park. New types of fracture surface morphologies have been observed which enabled the discerning of incipient joints and consequent fracture growth in these rocks. Incipient jointing in the sandstone is mostly manifested by elliptical and circular fractures (meters to tens meters across) initiating from independent origins. They interfere with each other and grow to larger circular fractures producing exfoliation surfaces up to hundreds of meters across. Less frequently, series of large concentric undulations demonstrate the propagation of a large fracture front producing exfoliation from an individual origin. One such fracture front reveals refraction of undulations at a layer boundary. Certain en echelon fringes surround the joint mirror plane with well defined rims of en echelons and hackles which enable the determination of the tensile fracture stress, {sigma}f. Arches in Zion National Park are ubiquitous in shape and size, revealing stages in their evolution by a mechanical process, which was associated with exfoliation, but independent of local faulting. Exfoliation and arching mostly occurred on vertical surfaces of N-NNW and NE sets of prominent joints, but there are also deviations from this general trend. In Yosemite National Park large exfoliations (hundreds of meters in size) developed on the El Capitan cliff by the interaction and merging of many previous smaller incipient joints that vary in size from meters to tens of meter.

  1. Periodic Spacing of Channel-Spanning Potholes in Navajo Sandstone, Henry Mountains Utah: Implications for Propagation of Incision Pulses across Tributary Junctions

    NASA Astrophysics Data System (ADS)

    Barnes, C. M.; Sklar, L. S.; Whipple, K. X.; Johnson, J. P.

    2004-12-01

    Incision of the Colorado River at Glen Canyon over the past ~1 Ma triggered pulses of incision that have migrated upstream through tributary drainages. The rate of incision of small tributaries often lags behind that of trunk streams, creatng over-steepened reaches at the tributary junction. In the arid Colorado Plateau, many of these low-order tributaries in massive lithologies have developed sequences of channel-spanning, periodically-spaced pothole bedforms. Although the dynamics of pothole formation and evolution are poorly understood, the occurrence of potholes correlates with super-critical flow and tools-limited conditions. We are exploring the hypothesis that pothole spacing and other profile attributes can be used to reconstruct the propagation of waves of incision through a drainage network. Here we report preliminary results of a field study of potholed reaches in steep, low-order channels draining Navajo Sandstone in the Henry Mountains, Utah. Our survey focused on channels where overlying sedimentary units and pediment deposits have largely been removed from the Navajo Sandstone. We surveyed six tributaries of the middle fork of Trail Canyon, and one tributary of Milk Creek, which are, in turn, minor tributaries of the Colorado River. We surveyed the long profile of each channel using a 5-m rod, 100-m tape, and a clinometer. In bedrock reaches, we focused on quantifying the spacing of alternating pothole steps and bedrock chutes, and the elevation change within and between potholes steps. We also characterized individual potholes by width, depth, maximum sediment size captured, and direction of flow recirculation. In alluviated reaches, we measured the bankfull width and depth to estimate relative differences in bankfull discharge. We also measured channel geometry in higher-order trunk streams at the junctions with the surveyed tributaries. Our preliminary results include the successful prediction of locations where potholed channels were found, by

  2. Field guide to sedimentary structures in the Navajo and Entrada sandstones in southern Utah and northern Arizona: Chapter in Field-trip guidebook, 100th annual meeting, The Geological Society of America, Phoenix, Arizona, October 26-29, 1987

    USGS Publications Warehouse

    Rubin, David M.; Hunter, Ralph E.

    1987-01-01

    This field-trip guide describes the common sedimentary structures that occur in eolian sands. The outcrops that are described occur in the Navajo and Entiaia Sandstones between the areas of Page, Arizona and St. George, Utah (figure I), but the sedimentary structures of these two sandstones are typical of most eolian deposits. The main part of the guide discusses the geologic setting and the origin of the various structures, and the road log discusses which structures are best displayed at selected outcrops.

  3. Reconstruction and geochemical modelling of the diagenetic history of the middle Jurassic Oseberg sandstone reservoir, Oseberg Field, Norwegian North Sea

    SciTech Connect

    Girard, J.P.; Sanjuan, B.; Fouillac, C.

    1995-08-01

    A detailed multidisciplinary integrated study of the Middle Jurassic Oseberg reservoir in 13 wells of the Oseberg field, Norwegian North Sea, was carried out in order to (1) reconstruct precisely the timing, conditions and spatial variation of diagenetic transformations (2) characterize the nature and origin of the diagenetic fluids, and (3) develop a geochemical model of the observed diagenesis. The 20-60 in thick Oseberg Formation occurs at depths of 2.5 to 3.2 km, and at present temperatures ranging from 100 to 125{degrees}C. The detrital assemblage is mainly composed of quartz, K-feldspar, albrite, muscovite and lithic clay clasts, and is very homogeneous throughout the study area. The chronological sequence of diagenetic phases established from petrographic observations includes: minor siderite and pyrite, K-feldspar overgrowths, ankerite, feldspar dissolution, vermiform, kaolinite, quartz overgrowths, poikilotopic Fe-rich calcite, dickite. Diagenetic temperatures were determined from fluid inclusions in ankerite, quarts and calcite. Combination with modelled burial/thermal history permitted to constrain approximate ages and duration of major diagenetic events. Isotopic compositions of diagenetic cements indicate that meteoric water was (and still is) a major constituant of diagenetic fluids. Present formation waters are fairly similar chemically and isotopically at reservoir scale and represent mixing of three endmembers: seawater, meteoric water and primary evaporative brine. Stability diagrams and chemical geothermometers suggest that formation fluids are close to equilibrium with the host sandstone at present reservoir temperatures. Geochemical modelling of the diagenetic evolution of water-reservoir interactions was carried out using the EQ3/6 code and the Allan{sup TM}/Neptunix integrated simulator system. Results emphasize the importance of circulations of large volumes of fluid within the reservoir throughout the diagenetic history.

  4. Degradation processes and consolidation of Late Jurassic sandstone dinosaur tracks in museum environment (Museum of Lourinhã, Portugal)

    NASA Astrophysics Data System (ADS)

    Leal, Sofia; mateus, Octavio; Tomas, Carla; Dionisio, Amelia

    2014-05-01

    The current study aims to conciliate conservation and restoration museology diagnosis with paleontological and geological curational needs and has, as subject of study, dinosaur footprints (vertebrates fossils). The footprints have been being exposed since 2004 in the paleontology hall of the Museum of Lourinhã, Portugal, and are part of a important paleontological collection of Late Jurassic vertebrate fossils from Lourinhã Formation. Presently, it is considered a unique heritage in danger of disappearing due to high decay level of disaggregation of its geological structure. The dinosaur footprints, (ML557) found, more precisely, on a coastline cliff in Lourinhã, Porto das Barcas, Lagido do Forno (coordinate 39° 14. 178'N, 9° 20. 397'W), Jurassic period, on the 5th of June 2001, by Jesper Milàn. This cliff of high slope presents sedimentary stratigraphic characteristics of a sandstone/siltstone of gray and red colors, by the '' Munsell scale and Color Chart''. Geological the tracks are Late Jurassic in age, and colected in the Lourinhã Formation, Praia Azul Member, of the Lusitanian Basin. There are three natural infills tridactyl tracks, possibly ascribed to ornithopod, a bipedal herbivore, resultant of a left foot movement, right and left. Footprints have 300-400mm of wide and 330-360mm of height with round fingers, which are elongated due to some degradation/erosion. In 2001, the footprints were collected from the field, cleaned, consolidated and glued in the laboratory of the Museum of Lourinhã before being exhibited in a museum display. Stone matrix was removed and a consolidation product applied, probably a polyvinyl acetate, of the brand Plexigum. The footprint with broken central digit was glued with an epoxy resin, Araldite. Both applied products were confirmed by analysis of µ-FTIR (Fourier Transform Infrared Spectroscopy) and both presented colour change and detachment surface problems. After collecting and storing, in 2004, footprints were

  5. Provenance of Late Carboniferous to Jurassic sandstones for southern Taimyr, Arctic Russia: A comparison of heavy mineral analysis by optical and QEMSCAN methods

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaojing; Pease, Victoria; Omma, Jenny; Benedictus, Aukje

    2015-11-01

    Sandstone framework-grain petrography, optical and QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) heavy mineral analysis carried out on 40 samples collected from east and west southern Taimyr are used to constrain the provenance and tectonic history of Late Carboniferous to Late Jurassic siliciclastic sequences. The tectonic settings of provenance evolved gradually from a mix of volcanic arc and recycled orogen to craton interior. Much of the detritus in the Late Paleozoic to Mesozoic siliciclastic succession came from proximal sources with contributions from multi-type source rocks including acid igneous rocks, basalts, sedimentary rocks and low to medium-grade metamorphic rocks. Carboniferous to Permian sandstones contain low-diversity suites of heavy minerals, including apatite, tourmaline, zircon, rutile, Cr-spinel, monazite and titanite. Cr-spinel indicates probable influx from exposed ophiolitic basement. Abundant euhedral zircon and apatite suggest a volcanic arc source related with Uralian collision. The appearance of garnet in the early Triassic signals the unroofing of a metamorphic source. The abrupt increase of clinopyroxene in Middle to Late Triassic sandstones indicates the influx of detritus from basic rocks related with Siberian Trap magmatism. The decrease of Cr-spinel and an abundance of staurolite in Jurassic samples indicate that unroofing of an ophiolitic source ceased and that stripping of a different thrust sheet containing plenty of staurolite-bearing metamorphic rocks commenced.

  6. Rock doughnut and pothole structures of the Clarens Fm. Sandstone in the Karoo Basin, South Africa: Possible links to Lower Jurassic fluid seepage

    NASA Astrophysics Data System (ADS)

    Grab, Stefan; Svensen, Henrik

    2011-08-01

    South Africa has a wealth of sandstone landforms, yet many of these have not been examined in detail to expand knowledge on their morphology and process origins. Here we present data on primary morphological statistics, rock hardness, surface roughness and petrographic investigations of rock doughnuts and associated pothole structures in Golden Gate Highlands National Park (GGHNP) and in the Witkop III complex, with the aim of using such data and field observations to argue their likely origins. Schmidt hammer R-values indicate consistently harder doughnut rims (mean = 48.7; n = 150) than the enclosed potholes (mean = 37.8; n = 150) and surrounding sandstone platform (mean = 39.7; n = 250). The petrography of Clarens Fm. Sandstone shows that the typical whitish sandstone is affected by intense chemical weathering. Pothole rims and the irregular reddish crust typical of the Witkop III outcrops show a secondary cementation by microcrystalline silica. Although preservation of old land surfaces is difficult to prove, small and circular pipe structures filled with calcite-cemented sand are present locally surrounding the Witkop III hydrothermal complex, and represent conduits for fluidized sand. Based on the morphologies of the Witkop III summit with the associated potholes and pipes, we hypothesize that they are remnants of morphologies created by Jurassic fluid seepage, with a superimposed and secondary silica cementation. Given that fluidization structures evidently occur in Clarens Fm. Sandstone, as is the case at Witkop, such mechanisms could possibly have contributed to the observed rock doughnut structures elsewhere on Clarens Fm. Sandstones, such as at the GGHNP where the rock doughnut morphological attributes are typical to landforms originating from fluid venting.

  7. Becoming Navajo.

    ERIC Educational Resources Information Center

    Lee, Rolland D.

    1992-01-01

    A 15-year-old Navajo artist, R. D. Lee, tells about his heritage and his painting. To this adolescent, culture means believing in and living the traditions of family. Lee hopes to be known as Navajo to Navajos but still accepted as a person out in the world. (SLD)

  8. Erosional remnants and adjacent unconformities along an eolian-marine boundary of the Page Sandstone and Carmel Formation, Middle Jurassic, south-central Utah

    SciTech Connect

    Jones, L.S.; Blakey, R.C. . Dept. of Geology)

    1993-09-01

    Sandstone ridges along the marine-eolian boundary of the Middle Jurassic Page Sandstone (eolian) with the lower Carmel Formation (restricted marine) in south-central Utah have been identified as erosional remnants consisting of strata of siliciclastic sabkha and eolian origin. The ridges lie within two distinct units of the Thousand Pockets Tongue of the Page. Two equally plausible models explain the genesis of these ridges. One model involves (1) early cementation of eolian and sabkha strata, (2) wind erosion leading to development of yardangs and unconformities, (3) yardang tilting due to evaporite dissolution, and (4) renewed deposition and burial. The alternative model explains ridge development through (1) subsidence, with tilting, of eolian and sabkha strata into evaporites due to loading from linear dunes, (2) evaporite dissolution and unconformity development, and (3) renewed deposition and burial. These models provide important clues about the nature of a missing part of the rock record. Reconstruction of units that were deposited but later eroded improves paleogeographic interpretation and here indicates that the Carmel paleo-shoreline was considerably farther to the northwest than previously believed.

  9. THE NAVAJOS.

    ERIC Educational Resources Information Center

    Navajo Tribe Public Relations and Information Dept., Window Rock, AZ.

    A STUDY OF NAVAJO AMERICAN INDIANS IS PRESENTED. INCLUDED ARE THE TRIBE'S HISTORY, RESOURCES, ECONOMIC SITUATION, AND WAYS TO IMPROVE IT. THE NAVAJOS ARE DIFFERENT FROM OTHER AMERICAN INDIAN TRIBES IN THAT THEY ARE RAPIDLY INCREASING, THEY HAVE INCREASED THE SIZE OF THEIR RESERVATION, THEY STILL LIVE IN ISOLATION AND IN A PRIMITIVE FASHION, AND…

  10. Navajo Studies at Navajo Community College.

    ERIC Educational Resources Information Center

    Roessel, Ruth, Ed.

    The Navajo Studies Program at Navajo Community College consists of 2 major areas of study, the first of which includes courses dealing with the Navajos. This book deals with that portion of the program and provides a picture of selected Navajo Studies courses as taught at Navajo Community College. Contained in the book are the origin myths of the…

  11. Triassic and Jurassic rocks at Currie, Nevada Preliminary paleontologic evidence

    SciTech Connect

    Johnson, E.A.; Dubiel, R.F.; Brouwers, E.M. ); Litwin, R.J. ); Ash, S.R. ); Good, S.C. )

    1993-04-01

    A sequence of continental rocks overlies the Lower Triassic Thaynes Formation in a poorly exposed syncline near Currie in northeastern NV. The authors recognize four lithostratigraphic units above the Thaynes near Currie and provide new paleontologic data. In ascending order, unit 1 (120 ft) consists of reddish-brown, very fine grained sandstone. Unit 2 (50 ft) consists of light-gray, trough cross-stratified, coarse-grained, conglomeratic sandstone. Unit 3 (at least 500 ft) consists of green, red, and brown sandstone and mudstone. Unit 4 occurs as isolated outcrops of reddish-orange, fine- to medium-grained sandstone. New fossil evidence, while not definitive, constrain the age of this sequence. Plant megafossils in unit 1 include (1) a specimen with narrow ovate leaves, possibly from an early Mesozoic conifer and (2) abundant fragments of probable Neocalamites. The presence of these fossils and the absence of any angiosperm leaves or wood fragments suggest an early Mesozoic age. Ostracodes in unit 3 are exclusively Darwinula sp., and their association with conchostracans in the absence of younger ostracodes suggests a Triassic age. Finally, two small outcrops, previously mapped as Triassic/Jurassic, contain the gastropods Pilidae indet. and Lymnaea sp., which resemble Late Cretaceous to Paleocene faunas. The sequence is similar to the nearest Lower Mesozoic section on the Colorado Plateau at Cove Fort, Utah, 165 miles to the southeast. The authors' new evidence supports the longstanding correlation of units 1--4 with the Lower Triassic Moenkopi Formation (part), the Shinarump and Petrified Forest Members of the Upper Triassic Chinle Formation, and the Lower Jurassic Navajo Sandstone of the Plateau. These rocks at Currie demonstrate that the Early Mesozoic depositional systems of the Colorado Plateau extended at least this far west and provide constraints on Early Mesozoic tectonism in the eastern Great Basin.

  12. Siderite (FeCO3)—the Hidden (but Primary) Player in Iron Diagenesis of Non-Marine Sandstones

    NASA Astrophysics Data System (ADS)

    Loope, D.; Kettler, R. M.

    2015-12-01

    Siderite precipitates in reducing pore waters in which iron reduction exceeds sulfate reduction. Abundant siderite should be expected in non-marine strata in which a reductant was present. The Triassic Shinarump Member (Chinle Fm) and Cretaceous Dakota Fm are fluvial and contain siderite in outcrops of floodplain mudstones. Siderite is present in cores of Dakota channel sandstones. Rinded and jointed iron-oxide concretions, Wonderstone patterns, and rhombic, iron-oxide pseudomorphs are present in outcrops of these sandstones. Vascular plants growing on floodplains provided the reductant. Similar concretions, patterns, and pseudomorphs are present in outcropping eolian cross-strata of the Jurassic Navajo Sandstone and in fluvial sandstone of the Cambrian Umm Ishrin Fm. Bleached sandstones indicate reductant was present in both units during late diagenesis. Because Jurassic deserts and Cambrian river systems lacked vascular plants, extra-formational methane was the likely reductant. We interpret the various iron-oxide-cemented phenomena of the Shinarump, Dakota, Navajo, and Umm Ishrin as products of siderite oxidation that accompanied exhumation. In the Navajo, large concretions are enclosed in thick sheaths of iron-oxide cement. Through-going horizontal and vertical joints cut sheaths. Outside concretion sheaths, joints are unassociated with iron-oxide cements, but inside the sheaths, thick cement zones are present on both sides of (still-open) joints. Joints were conduits for oxidizing water entering the concretions. Redox gradients formed on both sides of joints and iron oxide accumulated as Fe+2 diffused from dissolving siderite toward joints and O2 diffused away from joints. Horizontal joints formed <100 m from the land surface. Iron-oxide accumulations on the horizontal joints and on the vertical joints that abut them (see figure) are evidence that siderite oxidation is ongoing and linked to exhumation.

  13. Navajo Studies at Navajo Community College.

    ERIC Educational Resources Information Center

    Hatathli, Ned

    The document covers the Navajo Studies Program (NSP) at Navajo Community College (NCC). The Navajo Studies Program differs from other Indian Studies Programs in 7 ways, e.g.: (1) it is located on the Navajo Reservation and controlled by the tribe; (2) NCC incorporates Indian studies into every individual program and area of concentration--English…

  14. Navajo Justice.

    ERIC Educational Resources Information Center

    Yazzie, Robert

    2000-01-01

    The Navajo Nation has eliminated jail time for 79 offenses and required traditional peacemaking in criminal cases, primarily involving family violence. Peacemaking entails examination of the criminal act by all involved, family responsibility for its members, and symbolic restitution. The change promotes prevention and child protection by breaking…

  15. Annual monsoon rains recorded by Jurassic dunes.

    PubMed

    Loope, D B; Rowe, C M; Joeckel, R M

    2001-07-01

    Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events. PMID:11452305

  16. Navajo Electrification Demonstraiton Project

    SciTech Connect

    Larry Ahasteen, Project Manager

    2006-07-17

    This is a final technical report required by DOE for the Navajo Electrification Demonstration Program, This report covers the electric line extension project for Navajo families that currently without electric power.

  17. Architectural studies of Jurassic-Cretaceous fluvial units, Colorado Plateau

    SciTech Connect

    Miall, A.D.; Bromley, M.H.; Cowan, E.J.; Turner-Peterson, C.E.

    1989-03-01

    A sixfold hierarchy of architectural elements and bounding surfaces evolved from outcrop studies of three fluvial units: Westwater Canyon member (WCM), Morrison Formation, Upper Jurassic; Torrivio sandstone member (TSM), Gallup Sandstone, Upper Cretaceous, northwestern New Mexico; and Kayenta Formation (KF), Lower Jurassic, southwestern Colorado. This hierarchy is discussed.

  18. Strong Navajo Marriages

    ERIC Educational Resources Information Center

    Skogrand, Linda; Mueller, Mary Lou; Arrington, Rachel; LeBlanc, Heidi; Spotted Elk, Davina; Dayzie, Irene; Rosenbrand, Reva

    2008-01-01

    The purpose of this qualitative study, conducted in two Navajo Nation chapters, was to learn what makes Navajo marriages strong because no research has been done on this topic. Twenty-one Navajo couples (42 individuals) who felt they had strong marriages volunteered to participate in the study. Couples identified the following marital strengths:…

  19. Navajo Adult Basic Education.

    ERIC Educational Resources Information Center

    Navajo Community Coll., Tsaile, AZ.

    The objectives of this Special Experimental Demonstration Project in Adult Basic Education for the Navajo were: (1) to raise the educational and social level of Navajo adult students who are unable to read, write, and speak English; (2) to assist the Navajo adult students to take advantage of occupational and vocational training programs; (3) to…

  20. Comparison of sandstone reservoir geometry in a valley-fill depositional sequence and a deltaic progradational sequence, Middle Jurassic, Yorkshire, England

    SciTech Connect

    Eschard, R.; Ravenne, C.; Houel, P.

    1989-03-01

    The geostatistic simulations elaborated by the reservoir geology group of the IFP and the Geostatistic Center of the Ecole des Mines (HERESI GROUP) are based on the interpretation of representative outcrops of littoral to deltaic deposits. The methodology includes some detailed studies of large outcrops in terms of reservoir geology, a computation of the geological and petrophysical parameters, the conditional simulation of reservoir geometry, and their internal heterogeneities by geostatistic methods. Two sites, Cloughton and Ravenscar, have been selected along the Yorkshire coast in the Middle Jurassic siliciclastic series. The Ravenscar Group series (a stratigraphic and sedimentologic equivalent of the Brent Formation in the North Sea) is well exposed in wide, extended cliffs. The two-dimensional geometry of the reservoirs is reconstructed from photomosaics and surveying. Their three-dimensional architecture is controlled by core drills located just behind the studied cliffs. The wells are full-cored wire-line log (gamma ray and dipmeter) recorded, and porosity and permeability measurements are made every 20 cm in reservoir levels.

  1. Navajo Biographies. Volume I.

    ERIC Educational Resources Information Center

    Hoffman, Virginia

    The life stories of eight Navajo ("Dine", their term for themselves) leaders are presented in volume one of this collection of biographies. Interspersed with portraits, drawings, and maps, the narrative chronologically covers the time period from 1766 when the Navajos lived on land under the rule of Spain into the twentieth century and dealings…

  2. Navajo Wisdom and Traditions.

    ERIC Educational Resources Information Center

    Yazzie, Ethelou

    The oral literature of the Navajo people generally falls into two categories: the sacred stories and the folk tales, which often, but not always, point a moral. Sacred stories relate the Navajo's emergence history. These stories tell how the universe holds two kinds of people: the "Earth Surface People" (both living and dead) and the "Holy People"…

  3. Our Friends -- The Navajos.

    ERIC Educational Resources Information Center

    Navajo Community Coll. Press, Tsaile, AZ.

    Papers in this collection reflect the academic and on-reservation learning experiences of institute participants exposed to: Indian arts and crafts; the Navajo language; the Navajo people in their own homes, schools, and communities; basic knowledge of Indians; ceremonies, community meetings, and neighboring reservations; and major problems and…

  4. The Navajo Yearbook.

    ERIC Educational Resources Information Center

    Young, Robert W., Comp.

    The Navajo Yearbook began as an annual report to relate progress in carrying out provisions of the Navajo-Hopi Long Range Rehabilitation Act (P.L. 474 - 81st Congress), but the scope has been expanded to include all programs conducted on the reservation. This volume, the eighth in the series, is designed to reflect changing problems, changing…

  5. Navajo-ABLE: Replication Model Navajo Assistive Technology Loan Program. Final Program Evaluation.

    ERIC Educational Resources Information Center

    Norton, Katie Jebb

    This final report discusses the activities and outcomes of the Navajo Assistive Bank of Loanable Equipment (Navajo-ABLE), a federally funded program designed to provide assistive technology (AT) devices, services, technical information, funding information, and training for Navajo children and youth with disabilities. The program was operated and…

  6. NAVAJO ELECTRIFICATION DEMONSTRATION PROJECT

    SciTech Connect

    Terry W. Battiest

    2008-06-11

    The Navajo Electrification Demonstration Project (NEDP) is a multi-year project which addresses the electricity needs of the unserved and underserved Navajo Nation, the largest American Indian tribe in the United States. The program serves to cumulatively provide off-grid electricty for families living away from the electricty infrastructure, line extensions for unserved families living nearby (less than 1/2 mile away from) the electricity, and, under the current project called NEDP-4, the construction of a substation to increase the capacity and improve the quality of service into the central core region of the Navajo Nation.

  7. Contemporary Navajo Affairs: Navajo History Volume III, Part B.

    ERIC Educational Resources Information Center

    Eck, Norman K.

    Written specifically for Navajo junior high through college students, but also serving those interested in modern reservation developments and processs, the third volume of a curricular series on Navajo history provides a synthesis of data and pictorial records on current events in the areas of Navajo government, economic development, and health.…

  8. Marine Jurassic lithostratigraphy of Thailand

    NASA Astrophysics Data System (ADS)

    Meesook, A.; Grant-Mackie, J. A.

    Marine Jurassic rocks of Thailand are well-exposed in the Mae Sot and Umphang areas and less extensively near Mae Hong Son, Kanchanaburi, Chumphon and Nakhon Si Thammarat, in the north, west, and south respectively. They are generally underlain unconformably by Triassic and overlain by Quaternary strata. Based mainly on five measured sections, fourteen new lithostratigraphic units are established: (in ascending order) Pa Lan, Mai Hung and Kong Mu Formations of the Huai Pong Group in the Mae Hong Son area; Khun Huai, Doi Yot and Pha De Formations of the Hua Fai Group in the Mae Sot area; Klo Tho, Ta Sue Kho, Pu Khloe Khi and Lu Kloc Tu Formations of the Umphang Group in the Umphang area; and the Khao Lak Formation in the Chumphon area. Mudstone, siltstone, sandstone, limestone and marl are the dominant lithologies. Mudstones, siltstones and sandstones are widespread; limestones are confined to the Mae Sot, Umphang, Kanchanaburi and Mae Hong Son areas; marls are found only in Mae Sot. The sequences are approximately 900 m thick in Mae Sot and 450 m thick in Umphang and are rather thinner in the other areas, particularly in the south. Based on ammonites, with additional data from bivalves and foraminifera, the marine Jurassic is largely Toarcian-Aalenian plus some Bajocian. Late Jurassic ages given previously for strata in the Mae Sot and Umphang areas have not been confirmed.

  9. Walking in Navajo Footprints.

    ERIC Educational Resources Information Center

    Butler, Katie B.

    This module presents a guide for the study of the Navajo Indians' life and customs as they existed about thirty years ago. The length of time necessary to complete the activities, which are designed for use in kindergarten through third grades, may vary from one to two weeks. The module includes language, science, mathematics, art, music, dramatic…

  10. The Story of Three Navajo Women

    ERIC Educational Resources Information Center

    Wood, Beth; Barry, Tom

    1978-01-01

    The place of Navajo women on the reservation (as breadwinners, caretakers, and leaders) has suffered from a century of Anglo control. Three Navajo women tell how Navajos can effect change through the strength of their women. (Author/AM)

  11. Navajo Nation Educational Hearings, 1975.

    ERIC Educational Resources Information Center

    Navajo Tribe, Window Rock, AZ.

    Part of an effort by the Navajo Division of Education to formulate a comprehensive educational plan, this document includes testimony by people representing the five agency divisions on the Reservation (Shiprock, Crownpoint, Chinle, Tuba City, and Fort Defiance) and the public school districts serving Navajos. Also included is a synthesis of the…

  12. Towards a Navajo Indian Geometry.

    ERIC Educational Resources Information Center

    Pinxten, Rik; And Others

    This book examines the Navajo system of spatial knowledge and describes a culture-based curriculum for the development of an intuitive geometry based on the child's experience of the physical world. Aspects of the Navajo cosmology relevant to spatial knowledge are discussed: the structure of the world; the dynamic nature of the universe;…

  13. Piagetian Conservation in Navajo Children.

    ERIC Educational Resources Information Center

    Odell, Sandra J.; Ferraro, Douglas P.

    In order to determine the cognitive development of Navajo children in terms of Piagetian conservation of number, mass, and continuous quantity, 168 Navajo children at seven different age levels from 5 to adult were presented with a series of three conservation tasks. The tasks consisted of a standard object and an equivalent object that could be…

  14. NAVAJO NATION HAZARDOUS WASTE SITES

    EPA Science Inventory

    This point coverage represents the locations of hazardous waste sites on the Navajo Nation Indian Reservation. The point locations were delineated on 1:24,000 scale US Geological Survey (USGS) topographic maps by staff from the Navajo Nation EPA, Resource Conservation & Reco...

  15. Fault evolution in volcanic tuffs and quartz-rich eolian sandstone as mechanical analogs for faulting in Martian pyroclastic deposits

    NASA Astrophysics Data System (ADS)

    Okubo, C. H.

    2014-12-01

    In order to establish a foundation for studies of faulting in Martian rocks and soils in volcanic terrain, the distribution of brittle strain around faults within the North Menan Butte Tuff in the eastern Snake River Plain, Idaho and the Joe Lott Tuff Member of the Mount Belknap Volcanics, Utah, has been recently described. These studies employed a combination of macroscopic and microscopic observations, including measurements of in situ permeability as a proxy for non-localized brittle deformation of the host rock. In areas where the tuff retained its primary granular nature at the time of deformation, initial plastic yielding in both tuffs occurred along deformation bands. Both compactional and dilational types of deformation bands were observed, and faulting occurred along clusters of deformation bands. Where secondary alteration processes imparted a massive texture to the tuff, brittle deformation was accommodated along fractures. Host-rock permeability exhibits little variation from non-deformed values in the North Menan Butte Tuff, whereas host rock permeability is reduced by roughly an order of magnitude through compaction alone (no alteration) in the Joe Lott Tuff. To create a bridge between these observations in tuff and the more substantial body of work centered on deformation band formation and faulting in quartz-rich sandstones, the same techniques employed in the North Menan Butte Tuff and the Joe Lott Tuff have also been applied to a kilometer-scale fault in the Jurassic Navajo Sandstone in the Waterpocket Fold, Utah. These observations demonstrate that the manifestation of strain and evolution of faulting in the Mars-analog tuffs are comparable to that in quartz-rich sandstones. Therefore, current understanding of brittle deformation in quartz-rich sandstones can be used to inform investigations into fault growth within porous tuffs on Mars. A discussion of these observations, practical limitations, and directions for future work are presented here.

  16. To Be A Navajo. Second Edition, 1976.

    ERIC Educational Resources Information Center

    Begay, Shirley M., Ed.

    Designed to provide culturally relevant and interesting reading material in Navajo for Navajo speaking children, this booklet presents 20 short stories written and illustrated by students at Rough Rock Demonstration School. Intended to encourage Navajo speaking children, and others, to read and to instill pride in being a Navajo, the stories…

  17. Navajo Coal: Demands, Attitudes, and Environment.

    ERIC Educational Resources Information Center

    Goodman, James M.

    The operation of several coal mines with vast proven reserves on the Navajo reservation is a manifestation of conflict between: a power hungry external world; the preservationist attitudes of traditional Navajo culture; the disadvantaged socio-economic status of the average Navajo wage earner; and the Navajo Nation's long term needs for internal…

  18. A History of Navajo Clans. First Edition.

    ERIC Educational Resources Information Center

    Lynch, Regina H.; And Others

    Pen and ink drawings illustrate characterizations of 29 Navajo clans in this book, which is intended to acquaint young Navajo people and others with Navajo history and culture. The introduction discusses the significance of the Navajo clan system and the relationship among family bonds, self-esteem, and cultural values. The illustrated text tells…

  19. Provenance of Norphlet sandstone, northern Gulf Coast

    SciTech Connect

    Ryan, W.P.; Ward, W.C.; Kuglar, R.L.

    1987-09-01

    The Upper Jurassic Norphlet sandstone of the northern Gulf Coast is predominantly subarkose, with some arkose in the eastern area and sublitharenite and quartzarenite in the western area. Despite great depths of burial and despite feldspar and rock-fragment constituents, diagenesis has not appreciably altered the composition of Norphlet sandstone. Therefore, reconstruction of original composition of Norphlet sandstone presented little difficulty. Variation in detrital modes of the Norphlet suggests compositionally distinct source terranes. Samples from Florida, Alabama, and Mississippi reflect the influence of metamorphic and plutonic rocks of the Appalachian Piedmont Province and of Triassic-Jurassic volcanic rocks. Sandstones in east Texas, northern Louisiana, and southern Arkansas were derived from sedimentary and metasedimentary rocks of the Ouachita system. The Arbuckle Mountains and Llano uplift may have supplied trace amounts of quartzo-feldspathic and volcanic-rock fragments to the extreme western part of the study area. Norphlet sandstones represent a mixture of collision-orogen-derived sediment from the Appalachian and/or Ouachita system and continental-block-derived sediment from paleohighs and uplifts within the Gulf basin. However, Norphlet sandstones plot in the craton-interior and transitional-continental fields on Q-F-L and QM-F-Lt tectonic-provenance diagrams, because of mineralogically mature source rocks, elimination of unstable grains by abrasion and sorting during deposition, and/or sediment mixing from different source terranes.

  20. The nucleation and evolution of Riedel shear zones as deformation bands in porous sandstone

    NASA Astrophysics Data System (ADS)

    Ahlgren, S. G.

    2001-08-01

    The term Riedel shear zone refers to a geometric fracture pattern commonly associated with strike-slip fault systems. Using field mapping and three-dimensional digital modeling, the progressive temporal evolution of natural Riedel shear zones within exposures of the Jurassic Navajo Sandstone is interpreted from the spatial evolution of small-scale, incipient Proto-Riedel Zones (PRZs) to more completely developed systems. PRZs nucleate as a tabular zone of localized shearing marked by en échelon deformation bands, each of which is no more than a few mm wide and tens of cm long. These initial deformation bands have an opposite (antithetic) sense of slip with respect to the zone, and are oriented at an acute angle of 55-85° to the trend of the zone. With increasing strain, deformation bands and sedimentary markers become sheared through granular flow across the zone and assume a sigmoidal form. Subsequent bands develop as conjugate shear fractures within the strain-hardened axis of the PRZ. These antithetic driven systems are not directly linked to pre-existing or external structural elements and are not compatible with traditional synthetic driven models of Riedel shear zones.

  1. Analytical Bibliography of Navajo Reading Materials. Navajo Reading Study, Progress Report No. 3.

    ERIC Educational Resources Information Center

    Spolsky, Bernard; And Others

    English and Navajo language materials are described in this bibliography of reading materials primarily for elementary school students. The English language materials were developed to teach Navajo children about their own culture and could be used to form the base for a curriculum in English for Navajo students. The Navajo language materials were…

  2. Advances in Navajo Bilingual Education 1969-72. Navajo Reading Study Progress Report No. 20.

    ERIC Educational Resources Information Center

    Spolsky, Bernard, Ed.

    Advances in Navajo Bilingual Education are described in this progress report, in which bilingual education is presented as an element in aiding the community to be involved in and to control the Navajo education system. Also, the reports of 3 meetings concerning Navajo education are included. The report of a Navajo bilingual-bicultural materials…

  3. Navajo-Speaking Parents' Perceptions of Reasons for Navajo Language Attrition.

    ERIC Educational Resources Information Center

    Parsons-Yazzie, Evangeline

    1995-01-01

    Case studies of 10 Navajo families and their children revealed several factors as to why the children did not speak Navajo, including the amount of exposure the child had to Navajo speakers, the importance of Native language within the family, and lack of parental encouragement for learning Navajo. Includes recommendations of parents for…

  4. Jurassic Paleolatitudes, Paleogeography, and Climate Transitions In the Mexican Subcontinen

    NASA Astrophysics Data System (ADS)

    Molina-Garza, R. S.; Geissman, J. W.; Lawton, T. F.

    2014-12-01

    Jurassic northward migration of Mexico, trailing the North America plate, resulted in temporal evolution of climate-sensitive depositional environments. Lower-Middle Jurassic rocks in central Mexico contain a record of warm-humid conditions, which are indicated by coal and compositionally mature sandstone deposited in continental environments. Preliminary paleomagnetic data indicate that these rocks were deposited at near-equatorial paleolatitudes. The Middle Jurassic (ca. 170 Ma) Diquiyú volcanic sequence in central Oaxaca give an overall mean of D=82.2º/ I= +4.1º (n=10; k=17.3, α95=12º). In the Late Jurassic, the Gulf of Mexico formed as a subsidiary basin of the Atlantic Ocean, when the supercontinent Pangaea ruptured. Upper Jurassic strata, including eolianite and widespread evaporite deposits, across Mexico indicate dry-arid conditions. Available paleomagnetic data (compaction-corrected) from eolianites in northeast Mexico indicate deposition at ~15-20ºN. As North America moved northward during Jurassic opening of the Atlantic, different latitudinal regions experienced coeval Late Jurassic climatic shifts. Climate transitions have been widely recognized in the Colorado plateau region. The plateau left the horse-latitudes in the late Middle Jurassic to reach temperate humid climates at ~40ºN in the latest Jurassic. In turn, the southern end of the North America plate (central Mexico) reached arid horse-latitudes in the Late Jurassic. At that time, epeiric platforms developed in the circum-Gulf region after a long period of margin extension. We suggest that Upper Jurassic hydrocarbon source rocks in the circum-Gulf region accumulated on these platforms as warm epeiric hypersaline seas and the Gulf of Mexico itself were fertilized by an influx of wind-blown silt from continental regions. Additional nutrients were brought to shallow zones of photosynthesis by ocean upwelling driven by changes in the continental landmass configuration.

  5. Navajo Opposition to the Indian New Deal.

    ERIC Educational Resources Information Center

    Grinde, Donald A., Jr.

    1981-01-01

    Examines how the livestock reduction plan enforced by the Federal government in the 1930s resulted in drastically negative ecological, economic, and health consequences for the Navajo people. Describes manifestations of Navajo criticism and resistance. (GC)

  6. Navajo Pawn: A Misunderstood Traditional Trading Practice

    ERIC Educational Resources Information Center

    Kiser, William S.

    2012-01-01

    Navajo trading has been a crucial component of that tribe's localized economy for generations and has been the subject of much scholarship over the years. The role of the Navajo trader in influencing the types and styles of crafts that Navajos created as well as providing tribal members with an outlet for those items remains important to their…

  7. Navajo History: The Land and the People.

    ERIC Educational Resources Information Center

    Acrey, Bill P.

    This textbook for high school, college, or adult readers covers the history and culture of the Navajo People from their own perspective from the coming of American control in 1846 until 1978. Topics include the last Navajo war, the Long Walk, the impact of Navajo agents on policy, early traders and flourishing of crafts, settlement of reservation…

  8. A Utah Navajo History = Dineji Nakee' Naahane'

    ERIC Educational Resources Information Center

    Benally, Clyde; And Others

    This book presents Navajo history in two aspects--traditional stories that describe the ancestors of the Navajo and explain how the Earth-Surface World was changed from monster-filled chaos into the well-ordered world of today, and historical events from 1525 to today after the Navajos had settled in the Southwest. Events described include…

  9. The Origins of Navajo Youth Gangs.

    ERIC Educational Resources Information Center

    Henderson, Eric; Kunitz, Stephen J.; Levy, Jerrold E.

    1999-01-01

    Extended interviews with 50 Navajo men, aged 21 to 45, provided information on peer relationships and gang formation among male Navajo youth in the 1960s through the 1980s. Results suggest that gangs are an extreme example of traditional hell-raising among young Navajo men and that most gang members "age out" of their gangs. Suggestions for gang…

  10. A Bibliographic Essay Pertaining to Navajo Indians.

    ERIC Educational Resources Information Center

    Harrison, Scott

    Introduced by a discussion of the fact that most of the works cited describe Navajos as they "used to be" and an admonition against the common practice of placing all Navajos, or all Indians, under one stereotype, this bibliographic essay traces the history of Navajo contact with the white man and emphasizes efforts at educational development. Six…

  11. Jurassic petroleum trends in eastern Gulf Coastal Plain and central and eastern Gulf of Mexico

    SciTech Connect

    Mancini, E.A.; Mink, R.M.; Bearden, B.L.

    1986-05-01

    Three Jurassic petroleum trends can be delineated in Mississippi, Alabama, and Florida, and in the central and eastern Gulf of Mexico. These trends are recognized by characteristic petroleum traps, reservoirs, and hydrocarbon types. The source for the Jurassic hydrocarbons is Smackover algal mudstones. The Jurassic oil trend includes the area north of the regional peripheral fault systems in the tri-state area, and extends into the area north of the Destin anticline. Traps are basement highs and salt anticlines, with Smackover grainstones and dolostones and Norphlet marine, eolian, and wadi sandstones as reservoirs. This trend has potential for Jurassic oil accumulations in the eastern Gulf of Mexico. The Jurassic oil and gas-condensate trend includes the onshore area between the regional peripheral fault systems and Wiggins arch and extends into the area of the Destin anticline. Traps are basement highs, salt related anticlines, and extensional faults. Cotton Valley fluvial-deltaic sandstones, Haynesville carbonates and fluvial-deltaic sandstones, Smackover grainstones, packstones, dolostones, and marine sandstones, and Norphlet marine, eolian, and wadi sandstones serve as reservoirs. This trend contains most of the Jurassic fields in the eastern Gulf coastal plain. The trend has high potential for significant petroleum accumulations in the eastern Gulf of Mexico. The Jurassic deep natural gas trend includes the onshore area south of the Wiggins arch and extends into the Mississippi-Alabama shelf. Traps are faulted salt anticlines with basement highs as potential traps. Cotton Valley deltaic-strandplain sandstones and Norphlet eolian sandstones are the reservoirs. Several gas discoveries below 20,000 ft have been made in this trend in Mississippi and offshore Alabama. The trend has excellent potential for major gas accumulations in coastal Alabama and central Gulf of Mexico.

  12. Social services: the Navajo way.

    PubMed

    Belone, Cecilia; Gonzalez-Santin, Edwin; Gustavsson, Nora; MacEachron, Ann E; Perry, Timothy

    2002-01-01

    The development of child welfare services in Indian Country followed enactment of the 1975 Indian Education and Self-Determination Act and the 1978 Indian Child Welfare Act. These acts allow tribal contracting with the Bureau of Indian Affairs (BIA) to provide social services. Because the BIA model has not fit well with Navajo needs, the Navajo Nation Division of Social Services is creating a more holistic case management paradigm for child and family services, which is more congruent with its culture and its rural, sparsely populated land. PMID:12380626

  13. Navajos and National Nuclear Policy.

    ERIC Educational Resources Information Center

    Barry, Tom

    1979-01-01

    Describes the history of nuclear development in New Mexico, notes the cumulative detrimental effect on the Navajo Nation, and emphasizes federal inaction regarding health and safety standards and regulation in the nuclear power industry. Journal availability: see RC 503 522. (SB)

  14. Dinetah: Navajo History. Volume II.

    ERIC Educational Resources Information Center

    Roessel, Robert A., Jr.

    Using archaeological data, written chronicles of Spanish explorers and missionaries, and oral narratives and legends, the book traces the history of the Navajo people to their original homeland, Dinetah, located primarily off the present reservation in an area south and east of Farmington, New Mexico. The book discusses various theories on Navajo…

  15. Postsecondary Transitions among Navajo Indians.

    ERIC Educational Resources Information Center

    Jackson, Aaron P.; Smith, Steven A.

    2001-01-01

    A study examining postsecondary transition experiences interviewed 22 Navajos who were recent high school graduates. Prominent themes included family influence and pressures, discrepancy between high school and college learning environments, student-faculty relationships, vague educational and career plans, misconceptions about postsecondary…

  16. So Many Kinds of Navajos.

    ERIC Educational Resources Information Center

    Underhill, Ruth

    Written for both American Indian and non-Indian school children, the purpose of this book is to present a picture of the varied ways of life on the Navajo Reservation in 1970. Facts relating to health, education, employment, and living conditions are presented from the viewpoint of Denny Lincoln, a 12 year old orphan who is placed in a Navajo…

  17. Memo to Navajo Community Schools.

    ERIC Educational Resources Information Center

    Lee, George P.

    This handbook contains general resource information for program planning in Navajo education. Contained are listings on: 1) Key Questions; 2) Community Education and Local Control; 3) Education Laboratories; 4) Steps in Starting A Community College; 5) Recommended Books; 6) Bibliography of Instructional Resources; 7) Program Planning and Proposal…

  18. A Jurassic Shock-Aftershock Earthquake Sequence Recorded by Small Clastic Pipes and Dikes within Dune Cross-Strata, Zion National Park, Utah

    NASA Astrophysics Data System (ADS)

    Loope, D. B.; Zlotnik, V. A.; Kettler, R. M.; Pederson, D. T.

    2012-12-01

    Eolian sandstones of south-central and southeast Utah contain large volumes of contorted cross-strata that have long been recognized as products of liquefaction caused by seismic shaking. Unlike most sites where Navajo Sandstone is exposed, in Zion National Park (southwestern Utah), the Navajo contains very, very few contorted strata. We have, however, mapped the distribution of more than 1,000 small-scale, vertical pipes and dikes in uncontorted cross-strata of the Navajo at two small study sites in Zion. Pipes are 2-5 cm in diameter and up to 3 m long; dikes are ~6 cm wide. Clusters of the water-escape structures lie directly above and below numerous, near-horizontal bounding surfaces. Dikes are restricted to the wind-ripple strata that lie above the bounding surfaces. Pipes are common both above and below the bounding surfaces. In map view, most pipes are arranged in lines. Near the bounding surfaces, pipes merge upward with shallow dikes trending parallel to the lines of pipes. Pipes formed in grainflows—homogeneous, well-sorted sand lacking cohesion. Dikes formed above the bounding surface, in more-cohesive, poorly sorted, wind-ripple strata. As liquefaction began, expansion of subsurface sand caused spreading within the unliquified (capping) beds near the land surface. Dikes intruded cracks in the wind-ripple strata, and pipes rose from the better-sorted sand to interdune surfaces, following trends of cracks. Because the wind-ripple strata had low cohesive strength, a depression formed around each rupture, and ejected sand built upward to a flat-topped surface rather than forming the cone of a classic sand volcano. In one 3 m2 portion of the map area, a cluster of about 20 pipes and dikes, many with truncated tops, record eight stratigraphically distinct seismic events. The large dunes that deposited the Navajo cross-strata likely moved ~1m/yr. When, in response to seismic shaking, a few liters of fluidized sand erupted onto the lowermost portion of the

  19. Porosity prediction in sandstones using erosional unconformities

    SciTech Connect

    Shanmugam, G.

    1989-03-01

    Erosional unconformities of subaerial origin are created by tectonic uplifts and eustatic sea level fall. Most erosional unconformities developed on sandstones are planes of increased porosity because uplifted sandstones are exposed to undersaturated CO/sub 2/-charged meteoric waters that result in dissolution of unstable framework grains and cements. The chemical weathering of sandstones is intensified in humid regions by the heavy rainfall, soil zones, lush vegetation, and accompanying voluminous production of organic and inorganic acids. Erosional unconformities are considered hydrologically open systems because of abundant supply of fresh meteoric water and relatively unrestricted transport of dissolved constituents away from the site of dissolution, causing a net gain in porosity near unconformities. Thus, porosity in sandstones tends to increase toward overlying unconformities. Such porosity trends have been observed in hydrocarbon-bearing sandstone reservoirs in Alaska, Algeria, Australia, China, Libya, Netherlands, Norwegian North Sea, Norwegian Sea, and Texas. A common attribute of these reservoirs is that they were all subaerially exposed under heavy rainfall conditions. An empirical model has been developed for the Triassic and Jurassic sandstone reservoirs in the Norwegian North Sea on the basis of the observed relationship that shows an increase in porosity in these reservoirs with increasing proximity to the overlying base of Cretaceous unconformity. An important practical attribute of this model is that it allows for the prediction of porosity in the neighboring undrilled areas by recognizing the base of Cretaceous unconformity in seismic reflection profiles and by constructing subcrop maps.

  20. Transforming Biology Curriculum at Navajo Community College to Include Navajo and Western Cultural Knowledge.

    ERIC Educational Resources Information Center

    Garrison, Edward R.

    1994-01-01

    Describes how a college teacher used Navajo traditional knowledge to rethink the teaching of college biology. Suggests that teachers intimidated by the intricate Dine Philosophy of Education may integrate Navajo knowledge into their courses through focused research guided by Navajo consultants. Includes five examples of redesigned curricula for…

  1. Traders on the Navajo Reservation. A Report on the Economic Bondage of the Navajo People.

    ERIC Educational Resources Information Center

    Southwestern Indian Development, Inc., Window Rock, AZ.

    Conducted in 1969 by 8 Navajo students, this study investigates the Anglo trader in terms of his socioeconomic influence on the American Indians of the Navajo Reservation. Limited to 30 randomly selected trading posts located in the central and eastern portions of the Navajo Reservation, this study reflects findings derived from personal…

  2. The Situation of Navajo Literacy Projects. Navajo Reading Study Progress Report No. 17.

    ERIC Educational Resources Information Center

    Spolsky, Bernard

    The Navajo Reading Study has been prepared for a volume describing literacy projects in the indigenous languages of the Americas. In 1969-70, 2 surveys were made to determine the present language situation of 6-year-old Navajo children. For each survey, a simple questionnaire was sent to all teachers with Navajo 6-year-olds in their classes.…

  3. Mortality among Navajo uranium miners.

    PubMed Central

    Roscoe, R J; Deddens, J A; Salvan, A; Schnorr, T M

    1995-01-01

    OBJECTIVES. To update mortality risks for Navajo uranium miners, a retrospective cohort mortality study was conducted of 757 Navajos from the cohort of Colorado Plateau uranium miners. METHODS. Vital status was followed from 1960 to 1990. Standardized mortality ratios were estimated, with combined New Mexico and Arizona non-White mortality rates used for comparison. Cox regression models were used to evaluate exposure-response relationships. RESULTS. Elevated standardized mortality ratios were found for lung cancer (3.3), tuberculosis (2.6), and pneumoconioses and other respiratory diseases (2.6). Lowered ratios were found for heart disease (0.6), circulatory disease (0.4), and liver cirrhosis (0.5). The estimated relative risk for a 5-year duration of exposure vs none was 3.7 for lung cancer, 2.1 for pneumoconioses and other respiratory diseases, and 2.0 for tuberculosis. The relative risk for lung cancer was 6.9 for the midrange of cumulative exposure to radon progeny compared with the least exposed. CONCLUSIONS. Findings were consistent with those from previous studies. Twenty-three years after their last exposure to radon progeny, these light-smoking Navajo miners continue to face excess mortality risks from lung cancer and pneumoconioses and other respiratory diseases. PMID:7702118

  4. Navajo Changes--A History of the Navajo People = Dinetahgi Lahgo Ahoodzaa--Dine Bahane. Fifth-Eighth Grade Navajo Bilingual Bicultural Social Studies Curriculum.

    ERIC Educational Resources Information Center

    Wallace, Stephen; And Others

    The Navajo bilingual-bicultural social studies curriculum for grades 5-8 contains six chapters of Navajo history. The chapters trace Navajo history beginning with legends of the first Navajos and life in Dinetah and continuing through early contact with the Spaniards, conflict and defeat at the hands of the United States government, and the…

  5. An Ethnography of the Navajo Reproductive Cycle.

    ERIC Educational Resources Information Center

    Wright, Anne

    1982-01-01

    Describes the reproductive cycle (menarche, menstrual cycle, fertility and contraceptive use, and menopause) as experienced by two groups of contemporary Navajo women. Eighty Navajo women, 40 traditional and 40 acculturated, participated in the 1978 research project which focused on influences of menopause. (ERB)

  6. SURVEY REPORT--NAVAJO COMMUNITY COLLEGE.

    ERIC Educational Resources Information Center

    ASHE, ROBERT W.

    THIS PLAN FOR THE ESTABLISHMENT OF A NAVAJO JUNIOR COLLEGE GOES INTO ALL ASPECTS OF ITS ORGANIZATION. IT DESCRIBES THE PRESENT NAVAJO SCHOOL SYSTEM, WHICH IS A COMBINATION OF MISSION, PUBLIC, AND BUREAU OF INDIAN AFFAIRS OPERATIONS. FINANCIAL HELP TO STUDENTS WANTING MORE THAN A HIGH SCHOOL EDUCATION IS PRESENTLY INADEQUATE, THROUGH INCREASING. IF…

  7. Entrepreneurship and Economic Development: The Navajo Model.

    ERIC Educational Resources Information Center

    Devlin, J. Stuart; Carlin, William B.

    The Navajo Nation, in the summer of 1987, sponsored the Special Pre-Business Introduction for Navajo Students (SPINS) program through the business colleges at three universities: (1) University of Arizona; (2) University of New Mexico; and (3) New Mexico State University. SPINS provided entrepreneurial training, through entrepreneurship workshops,…

  8. "1970" Inter-Agency Health Meeting (Navajo).

    ERIC Educational Resources Information Center

    Arizona Commission of Indian Affairs, Phoenix.

    An inter-agency health meeting regarding health services for Navajo Indians is reported on in this document. The meeting, sponsored by the Arizona Commission of Indian Affairs, involved agencies such as the U.S. Public Health Service, Bureau of Indian Affairs, and the Navajo Tribe. Included in the proceedings are reports and remarks by…

  9. Defining Student Success through Navajo Perspectives

    ERIC Educational Resources Information Center

    Bowman, Colleen Wilma

    2013-01-01

    The purpose of this qualitative study was to determine the definition of student success as defined by the Navajo people. The data collection method used was the focus group. The data were collected from two geographical settings from two public schools located within the boundaries of the Navajo Indian Reservation. The focus group participants…

  10. Navajo Art--A Way of Life.

    ERIC Educational Resources Information Center

    Clover, Faith

    This curriculum unit on Navajo art consists of three lessons, each of which can stand alone or be used in conjunction with the others. Teacher and students will explore Navajo traditions in the unit and use the insight gained to create artworks that connect people to their community and natural environment. The key artworks provide the foundation…

  11. Sovereignty: The Navajo Nation and Taxation.

    ERIC Educational Resources Information Center

    Benson, Michael

    Contending that it is wrong for the Navajo Government to continue to neglect its citizens by not implementing a taxation program, this monograph is written to generate interest in and discussion of a taxation program and the Navajo Tax Commission, created in 1974. Specifically, this booklet presents basic information re: the financing of the…

  12. Navajo generating plant and Grand Canyon haze

    SciTech Connect

    Norris, J.E.

    1991-01-15

    This article examines the question of whether the Navajo generating plant pollution is contributing to pollution of the air in the Grand Canyon region. The topics include the regulatory context of the plant, the experiment known as the Winter Haze Intensive Tracer Experiment (WHITEX), the National Research Council evaluation of the WHITEX, and The Navajo Generating Station Visibility Study.

  13. Navajo Health Authority: Accomplishments--Future Goals.

    ERIC Educational Resources Information Center

    Navajo Health Authority, Window Rock, AZ.

    Accomplishments of the Navajo Health Authority (NHA) since it began in 1972 are presented in synopsis form in a report of programs underway at Window Rock and Shiprock, along with NHA goals: to promote development of Navajo Health manpower, preventive medicine, health education, and native healing sciences. After a brief review of executive and…

  14. Some Remarks on Navajo Geometry and Piagetian Genetic Theory.

    ERIC Educational Resources Information Center

    Pinxten, Rik

    1991-01-01

    Examines aspects of Navajo cosmology relevant to understanding Navajo spatial representations. Compares Navajo children's spatial knowledge with Piaget's findings about the development of geometric concepts in Swiss children. Describes classroom activities whereby Navajo children explore the geometry inherent in their cultural and physical…

  15. Navajo History to 1846: The Land and the People.

    ERIC Educational Resources Information Center

    Acrey, Bill P.

    This textbook for high school, college, or adult readers covers major areas of Navajo history from prehistoric times to 1846 from the Navajo point of view. A brief description of pre-Navajo cultures including the Hohokam, Mogollon, and Anasazi precedes the more detailed history of the arrival of the Navajo and contact with the Pueblo peoples.…

  16. When Navajos Had Too Many Sheep: the 1940's.

    ERIC Educational Resources Information Center

    Boyce, George A.

    The book is the story of the Navajos during the decade of forced stock reduction on the Navajo Reservation. This decade was marked by confusion, frustration, and bitterness on the part of the Navajo Nation. It is of the 1940's, during which the Navajos faced their greatest crisis since their removal to military confinement from 1864 to 1868, that…

  17. Geohydrology and effects of water use in the Black Mesa area, Navajo and Hopi Indian Reservations, Arizona

    USGS Publications Warehouse

    Eychaner, James H.

    1983-01-01

    The N aquifer is the main source of water in the 5,400-square-mile Black Mesa area in the Navajo and Hopi Indian Reservations in northeastern Arizona. The N aquifer consists of the Navajo Sandstone and parts of the underlying Kayenta Formation and Wingate Sandstone of Jurassic and Triassic age. Maximum saturated thickness of the aquifer is about 1,050 feet in the northwestern part of the area, and the aquifer thins to extinction to the southeast. Water is under confined conditions in the central 3,300 square miles of the area. To the east, north, and west of Black Mesa, the aquifer is exposed at the surface, and water is unconfined. The aquifer was in equilibrium before about 1965. Recharge of about 13,000 acre-feet per year was balanced primarily by discharge near Moenkopi Wash and Laguna Creek and by evapotranspiration. At least 180 million acre-feet of water was in storage. The estimated average hydraulic conductivity of the aquifer is 0.65 foot per day. The confined storage coefficient is estimated to be about 0.0004 where the aquifer is thickest, and the estimated unconfined storage coefficient ranges from 0.10 to 0.15. Ground-water withdrawals that averaged 5,300 acre-feet per year from 1976 to 1979 have caused water levels to decline in wells in the confined part of the aquifer. Withdrawals include an average of 3,700 acre-feet per year to supply a coal-slurry pipeline from a coal mine on Black Mesa. Six observation wells equipped with water-level recorders have been used to monitor aquifer response. The water level in one well 32 miles south of the mine declined 17 feet from 1972 through 1979 and 3.5 feet during 1979. A mathematical model of the N aquifer was developed and calibrated for equilibrium and nonequilibrium conditions. The model was used in part to improve estimates of aquifer characteristics and the water budget, and it successfully reproduced the observed response of the aquifer through 1979. The model results indicate that about 95 percent of

  18. Petrophysical Properties of Sandstones Containing Deformation Bands Versus Those With Fractures: the Importance of Grain Contact Strength to Fault-Zone Structure

    NASA Astrophysics Data System (ADS)

    Schneider, J. R.; Tobin, H. J.; Goodwin, L. B.

    2010-12-01

    In upper crustal fault zones, the majority of slip accumulates within a fault core, which is surrounded by a less deformed damage zone. Both the width and structural character of the damage zone affect its mechanical and hydrologic properties. Fault-related deformation can change rock mechanical properties, causing stress orientations to rotate in fault damage zones, and affecting seismicity over time. In addition, the types, densities, and orientations of structures in fault zones exert a first-order control on fault-zone permeability structure, permeability anisotropy, and flow pathways. For example, open-fracture damage zones enhance fault-parallel flow, whereas cataclastic deformation band networks slow flow in every direction except parallel to the line of intersection between bands. To improve our understanding of controls on damage zone character, we explored relationships between fault-zone structure and lithologic characteristics such as porosity and cement mineralogy in faulted quartz-rich sandstones. The sandstones chosen from fault sites in the Jurassic Navajo and Entrada sandstones in Utah, and the Cretaceous Mesaverde sandstone in Wyoming, exhibit a wide range in porosity. Samples collected include even greater variability in cements, from clay coatings on grains to patchy carbonate cement to grain-bridging quartz overgrowths and iron oxide cements. These variables demonstrably influence damage zone character, resulting in fractures in some locations and deformation bands in others (even within a single fault zone) and affecting deformation-band damage zone width. They likely influenced grain-contact strength also. Because ultrasonic velocity and related elastic moduli also vary with grain-contact strength, we measured P and S wave velocities as a function of confining pressure to 20 MPa as a sensitive proxy for grain-contact strength. More than 40 samples, including both host rock and rock with deformation bands, have been analyzed. Samples

  19. Effects of diagenesis on pore texture and petrophysical properties of sandstone reservior and its geological significance

    SciTech Connect

    Zhu, G.

    1982-01-01

    This paper deals with diagenesis of Yan-10 Sandstones, Yanan Series, jurassic-the main producing horizons in an exploratory area in Shan-Gan-Ning Basin, China. The effects of diagenesis on pore texture and petrophysical porperties of sandstones, its effects on forming trapping conditions for oil pools, the genesis of low permeability zone near the oil-water boundary, as well as secondary pores together with authigenic clay minerals of sandstones are presented. Furthermore, the paper describes briefly Yan-10 Sandstones in some other areas. 11 refs.

  20. Navajo Leadership and Government: A History. Sixth-Ninth Grade Navajo Bilingual-Bicultural Social Studies Curriculum.

    ERIC Educational Resources Information Center

    McCarty, T. L.; Wallace, Stephen

    This history of Navajo leadership and government, part of the sixth-ninth grade Navajo bilingual-bicultural social studies curriculum from the Navajo Curriculum Centers, covers types of government from the animal leaders of Navajo legend to modern times. The text is divided into five chapters: "The First Leaders,""New Neighbors--New…

  1. Exploring Jurassic Park.

    ERIC Educational Resources Information Center

    Simmons, Patricia E.; Wiley, Clyde

    1993-01-01

    Describes several student-tested activities built around "Jurassic Park." The activities feature students engaged in role-playing scenarios, investigative research projects, journal writing and communications skills activities, cooperative learning groups, and learning experiences that make use of reading skills and mathematical knowledge. (PR)

  2. Final Report - Navajo Electrification Demonstration Project - FY2004

    SciTech Connect

    Kenneth L. Craig, Interim General Manager

    2007-03-31

    The Navajo Electrification Demonstration Project (NEDP) is a multi-year projects which addresses the needs of unserved Navajo Nation residents without basic electricity services. The Navajo Nation is the United States' largest tribe, in terms of population and land. An estimated 18,000 Navajo Nation homes do not have basic grid-tied electricity--and this third year of funding, known as NEDP-3, provided 351 power line extensions to Navajo families.

  3. Final Report Navajo Transmission Project (NTP)

    SciTech Connect

    Bennie Hoisington; Steven Begay

    2006-09-14

    The Diné Power Authority is developing the Navajo Transmission Project (NTP) to relieve the constraints on the transmission of electricity west of the Four Corners area and to improve the operation flexibility and reliability of the extra-high-voltage transmission system in the region. The NTP creates the wholesale transmission capacity for more economical power transfers, sales, and purchases in the region. It will facilitate the development of Navajo energy resources, improve economic conditions on the Navajo Nation as well as allow DPA to participate in the western electrical utility industry.

  4. Kinaalda: The Pathway to Navajo Womanhood.

    ERIC Educational Resources Information Center

    Ryan, Danita Begay

    1988-01-01

    Presents a personal account of the Navajo ceremony of Kinaalda, performed when a girl reaches puberty. Describes ceremonial running, corn grinding, and grooming, and admonitions and blessings received from grandmother, elderly women of the tribe, and medicine man. (SV)

  5. The Navajo Culture Center: Purpose and Plans. A Shrine and Living Symbol for the Navajo Nation to Be Located at Navajo Community College, Tsaile, Arizona.

    ERIC Educational Resources Information Center

    Navajo Community Coll., Tsaile, AZ.

    Presenting its past, present, and future expectations, the Navajo Junior College anc the forthcoming Navajo Culture Center are described in detail in this publication. College information relative to the following is presented: (1) History and Origin; (2) Philosophy; (3) Objectives; (4) Purpose of the Navajo College (to serve the Navajo…

  6. Navajo Language Bibliography. Preliminary Edition, September 1973. Navajo Reading Study Progress Report No. 22.

    ERIC Educational Resources Information Center

    Kari, James

    Over the years the Navajo language has received more attention than any other American Indian language. The grammatical work represents all traditions in American Indian linguistic research, from the earliest descriptivism to the latest generative grammar. In addition, there exists a large amount of material written in Navajo and a plethora of…

  7. 40 CFR 49.5513 - Federal Implementation Plan Provisions for Navajo Generating Station, Navajo Nation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Federal Implementation Plan Provisions for Navajo Generating Station, Navajo Nation. 49.5513 Section 49.5513 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE INDIAN COUNTRY: AIR QUALITY PLANNING AND MANAGEMENT Implementation Plans...

  8. Dual Language = Saad Ahaah Sinil. A Navajo-English Dictionary. Revised Edition.

    ERIC Educational Resources Information Center

    Austin, Martha, Ed.; Lynch, Regina, Ed.

    A dual-language Navajo-English dictionary provides a chart of the Navajo kinship system, a two-page map of the Navajo Nation, and English equivalents for Navajo words in 46 linguistic and cultural categories. Included are words for: races (Indian and other ethnic groups); Navajo clans; age groups; Navajo ceremonies; body parts; sickness; clothing;…

  9. Pennsylvanian to Jurassic eolian transportation systems in the western United States

    USGS Publications Warehouse

    Peterson, F.

    1988-01-01

    The direction of sediment transport in eolian sandstones of Pennsylvanian to Jurassic age was interpreted from crossbedding resultants (vector means) obtained from studies of eolian rocks in the western U.S., supplemented by data from the few eolian units of eastern North America. These were compiled from the published or unpublished (theses) literature, from unpublished field data contributed by colleagues, or from measurements made for this study. In addition, new paleogeographic maps were compiled to evaluate the influence of geographic features on the atmospheric circulation patterns that are inferred from the crossbedding studies. Regionally, the crossbedding indicates northeasterly, northerly, or northwesterly winds (present coordinates) from Pennsylvanian through most of Middle Jurassic time. A rather abrupt change in wind directions occurred in late Middle Jurassic time (late part of the Callovian Age) when westerly wind patterns developed. By the Late Jurassic the winds shifted to southwesterly. Calculations of the consistency factor (vector mean strength) made from region-wide analyses of the resultants indicate fairly unidirectional winds from the Pennsylvanian through the Early Jurassic. Middle Jurassic circulation was more varied, judging from crossbedding studies in the lower part of the Entrada Sandstone. Crossbedding in Upper Jurassic eolian rocks of Wyoming and South Dakota yielded a random pattern but Upper Jurassic rocks farther south on the Colorado Plateau and adjoining areas show a return to a fairly unidirectional pattern. Comparing the resultants with their reconstructed paleogeographic setting shows surprisingly little influence of major geographic features on overall circulation patterns. However, the greatest amount of local variation occurred at or near highly indented shorelines where the temperature contrast between land and water produces local wind currents that may vary appreciably from regional circulation patterns. Although they

  10. Chapter 2. Assessment of undiscovered conventional oil and gas resources--Upper Jurassic-Lower Cretaceous Cotton Valley group, Jurassic Smackover interior salt basins total petroleum system, in the East Texas basin and Louisiana-Mississippi salt basins provinces.

    USGS Publications Warehouse

    Dyman, T.S.; Condon, S.M.

    2006-01-01

    The Jurassic Smackover Interior Salt Basins Total Petroleum System is defined for this assessment to include (1) Upper Jurassic Smackover Formation carbonates and calcareous shales and (2) Upper Jurassic and Lower Cretaceous Cotton Valley Group organic-rich shales. The Jurassic Smackover Interior Salt Basins Total Petroleum System includes four conventional Cotton Valley assessment units: Cotton Valley Blanket Sandstone Gas (AU 50490201), Cotton Valley Massive Sandstone Gas (AU 50490202), Cotton Valley Updip Oil and Gas (AU 50490203), and Cotton Valley Hypothetical Updip Oil (AU 50490204). Together, these four assessment units are estimated to contain a mean undiscovered conventional resource of 29.81 million barrels of oil, 605.03 billion cubic feet of gas, and 19.00 million barrels of natural gas liquids. The Cotton Valley Group represents the first major influx of clastic sediment into the ancestral Gulf of Mexico. Major depocenters were located in south-central Mississippi, along the Louisiana-Mississippi border, and in northeast Texas. Reservoir properties and production characteristics were used to identify two Cotton Valley Group sandstone trends across northern Louisiana and east Texas: a high-permeability blanket-sandstone trend and a downdip, low-permeability massive-sandstone trend. Pressure gradients throughout most of both trends are normal, which is characteristic of conventional rather than continuous basin-center gas accumulations. Indications that accumulations in this trend are conventional rather than continuous include (1) gas-water contacts in at least seven fields across the blanket-sandstone trend, (2) relatively high reservoir permeabilities, and (3) high gas-production rates without fracture stimulation. Permeability is sufficiently low in the massive-sandstone trend that gas-water transition zones are vertically extensive and gas-water contacts are poorly defined. The interpreted presence of gas-water contacts within the Cotton Valley

  11. Diagnosis and distress in Navajo healing.

    PubMed

    Csordas, Thomas J; Storck, Michael J; Strauss, Milton

    2008-08-01

    In contemporary Navajo society, traditional Navajo ceremonies, Native American Church prayer meetings, and Navajo Christian faith healing are all highly sought-after resources in the everyday pursuit of health and well-being. What is the nature of affliction among patients who turn to such forms of religious healing? Are these patients typically afflicted with psychiatric disorder? In this article we discuss 84 Navajo patients who participated in the Navajo Healing Project during a period in which they consulted one of these forms of healing. We present diagnostic results obtained from the Structured Clinical Interview for DSMIV (SCID) administered to these patients. We then present an ethnographically augmented analysis comparing the research diagnosis obtained via the SCID with a clinical diagnosis, with the diagnosis given by religious healers, and with the understanding of their own distress on the part of patients. These analyses demonstrate how a cultural approach contributes to the basic science and clinical understandings of affliction as well as to discussion of the advantages and limitations of DSM categories as descriptors of distress and disorder. PMID:18974670

  12. Recognition and source correlation of migrated hydrocarbons in Upper Jurassic Hareelv Formation, Jameson Land, east Greenland

    SciTech Connect

    Requejo, A.G.; Hollywood, J.; Halpern, H.I. )

    1989-09-01

    Organic geochemical analysis of an interbedded shales and sandstone sequence from the Upper Jurassic Hareelv Formation, Jameson Land, East Greenland, has revealed oil shows in the sandstones, consistent with petroleum generation and migration. A comparison of the molecular characteristics of extractable material from the sandstones with those of kerogen and bitumen from the shales indicates that the most likely origin of these shows is generation within the shales with expulsion and short-range migration into the sandstones. This conclusion is based on comparisons of biological marker distributions, stable carbon isotopic compositions of extractable material and kerogen, and pyrolysate compositions of kerogen and asphaltenes. Oil from a seep in the Savoia Halvo region south of Jameson Land can be correlated to the Jurassic sandstone oil shows based on similar isotopic compositions and asphaltene pyrolysate distributions. Impregnation of both sandstones and shales throughout the sequence by products generated at higher maturities is considered unlikely, but cannot be ruled out by the existing data. 18 figs., 6 tabs.

  13. Family Planning Attitudes of Traditional and Acculturated Navajo Indians.

    ERIC Educational Resources Information Center

    Ackerman, Alan; And Others

    To determine whether various indices of "acculturation" would predict attitudes towards family planning was the major purpose of a survey conducted among a highly educated group of Navajo people at Navajo Community College (NCC). Owned and operated by the Navajo Tribe, NCC served as a target survey model due to its 90% population of Navajo…

  14. Verb Nominalization and Categorization in Navajo Children's Speech.

    ERIC Educational Resources Information Center

    Iris, Madelyn Anne

    Verb nominalization in Navajo is a strategy by which children create category labels when the adult lexical item is not known; it allows for the creation of uniquely descriptive category labels. This study was based on a series of interviews with Navajo children aged four-and-a-half to approximately ten years, all native speakers of Navajo with…

  15. The Navajo Code Talkers: A Secret World War II Memorandum.

    ERIC Educational Resources Information Center

    Jevec, Adam; Potter, Lee Ann

    2001-01-01

    Provides background information on the development of and work performed by the Navajo code talkers during World War II. Includes teaching activities for classroom use as well as examples from the code. Includes the Navajo dictionary and words with the English and Navajo meaning. (CMK)

  16. Prospects for the Survival of the Navajo Language: A Reconsideration.

    ERIC Educational Resources Information Center

    Spolsky, Bernard

    This paper aims to reassess conclusions drawn in 1975 about the prospects for survival of the Navajo language. A study done at that time uncovered evidence that there was increasing knowledge of English among Navajo children, although knowledge of English was highly, positively correlated to the level of isolation from Navajo speakers. As a result…

  17. Analytical Bibliography of Navajo Reading Materials. Revised and Enlarged Edition.

    ERIC Educational Resources Information Center

    Spolsky, Bernard; And Others

    English and Navajo language materials are described in this annotated bibliography of reading materials which is part of the Navajo Reading Study funded by the Bureau of Indian Affairs. The English language materials were developed to teach Navajo children about their own culture and could be used to form the base for a curriculum in English for…

  18. The Fears of Navajo Children: Adaptation or Pathology?

    ERIC Educational Resources Information Center

    Tikalsky, Frank D.

    1988-01-01

    Examines the literature concerning the fears of children generally and Navajo children specifically, and reviews a recent cross-cultural study with Navajo informants. Suggests that high fear frequencies in Navajo children may not indicate pathology, but may demonstrate a cultural pattern with important adaptive value. Contains 10 references. (SV)

  19. Navajo Reading Study. Progress Report No. 4, December 1969.

    ERIC Educational Resources Information Center

    Murphy, Paul, Ed.

    A summary of the discussions of the Navajo Reading Study Conference, held on December 4-5, 1969, in Albuquerque, New Mexico, was presented in this report. A group of consultants met to discuss the collection of data and its analysis for a study on Navajo reading materials and the language of 6-year-old Navajo children. The consultants included Mr.…

  20. Mother Tongue Literacy and Language Renewal: The Case of Navajo.

    ERIC Educational Resources Information Center

    McCarty, Teresa L.; Dick, Galena Sells

    This paper discusses the contribution of school-based mother-tongue literacy to the maintenance and renewal of endangered languages, with Navajo as the case in point. Although Navajo claims the most speakers among U.S. indigenous languages, the absolute number and relative proportion of Navajo speakers have declined drastically in the last 30…

  1. 78 FR 17743 - Navajo Nation Disaster #AZ-00026

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... ADMINISTRATION Navajo Nation Disaster AZ-00026 AGENCY: U.S. Small Business Administration. ACTION: Notice... for the Navajo Nation (FEMA-4104- DR), dated 03/05/2013. Incident: Severe Freeze. Incident Period: 12...: Primary Areas: Navajo Nation and Associated Lands. The Interest Rates are: For Physical Damage:...

  2. 78 FR 17422 - Navajo Nation; Major Disaster and Related Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-21

    ... SECURITY Federal Emergency Management Agency Navajo Nation; Major Disaster and Related Determinations... Presidential declaration of a major disaster for the Navajo Nation (FEMA-4104-DR), dated March 5, 2013, and...''), as follows: I have determined that the damage to the lands associated with the Navajo...

  3. Navajo Adult Basic Education: Final Report 1971-1972.

    ERIC Educational Resources Information Center

    Navajo Community Coll., Tsaile, AZ.

    The thrust of the Navajo Adult Basic Education (NABE) program is aimed at three major objectives. First, it seeks to establish, through the study of history and current events, a feeling of pride in Navajo cultural heritage, promoting self-esteem and building self-confidence. Next, it prepares the Navajo to function better in those areas of the…

  4. Navajo Evaluators Look at Rough Rock Demonstration School.

    ERIC Educational Resources Information Center

    Begaye, John Y.; And Others

    Four prominent Navajo leaders evaluated Rough Rock Demonstration School by invitation of the school board. Inquiry was directed toward ascertaining the type of education Navajos desire for their children, the extent Indian culture should be included in the curriculum, and how Navajos want their schools operated. It was concluded that the student…

  5. Health Problems of the Navajo Area and Suggested Interventions.

    ERIC Educational Resources Information Center

    Kaltenbach, Charles

    Analysis of morbidity, mortality, and demographic data on Navajo people was undertaken to identify leading health problems in the Navajo area and to suggest intervention activities. Comparisons with total U.S. population were made to provide perspective. Data on Navajo mortality showed: a ratio of male to female deaths of 2:1, more than 50 percent…

  6. Middle Jurassic Topawa group, Baboquivari Mountains, south-central Arizona: Volcanic and sedimentary record of deep basins within the Jurassic magmatic arc

    USGS Publications Warehouse

    Haxel, G.B.; Wright, J.E.; Riggs, N.R.; Tosdal, R.M.; May, D.J.

    2005-01-01

    Among supracrustal sequences of the Jurassic magmatic arc of the southwestern Cordillera, the Middle Jurassic Topawa Group, Baboquivari Mountains, south-central Arizona, is remarkable for its lithologic diversity and substantial stratigraphic thickness, ???8 km. The Topawa Group comprises four units (in order of decreasing age): (1) Ali Molina Formation-largely pyroclastic rhyolite with interlayered eolian and fluvial arenite, and overlying conglomerate and sandstone; (2) Pitoikam Formation-conglomerate, sedimentary breccia, and sandstone overlain by interbedded silt- stone and sandstone; (3) Mulberry Wash Formation-rhyolite lava flows, flow breccias, and mass-flow breccias, with intercalated intraformational conglomerate, sedimentary breccia, and sandstone, plus sparse within-plate alkali basalt and comendite in the upper part; and (4) Tinaja Spring Porphyry-intrusive rhyolite. The Mulberry Wash alkali basalt and comendite are genetically unrelated to the dominant calcalkaline rhyolite. U-Pb isotopic analyses of zircon from volcanic and intrusive rocks indicate the Topawa Group, despite its considerable thickness, represents only several million years of Middle Jurassic time, between approximately 170 and 165 Ma. Sedimentary rocks of the Topawa Group record mixing of detritus from a minimum of three sources: a dominant local source of porphyritic silicic volcanic and subvolcanic rocks, identical or similar to those of the Topawa Group itself; Meso- proterozoic or Cambrian conglomerates in central or southeast Arizona, which contributed well-rounded, highly durable, polycyclic quartzite pebbles; and eolian sand fields, related to Middle Jurassic ergs that lay to the north of the magmatic arc and are now preserved on the Colorado Plateau. As the Topawa Group evidently represents only a relatively short interval of time, it does not record long-term evolution of the Jurassic magmatic arc, but rather represents a Middle Jurassic "stratigraphic snapshot" of the arc

  7. Diagenetic pathways for sandstones: The role of initial composition

    SciTech Connect

    Harris, N.B.

    1995-09-01

    The initial composition of a clastic section is critical in determining the diagenetic reactions that a sandstone will undergo during burial, reactions which strongly influence its reservoir properties. The role of initial composition is illustrated for Middle Jurassic sandstones of northwest Europe (including the Brent sandstone of the North Sea) and Tertiary sandstones of the Gulf of Mexico. The composition of the former evolves from arkose to quartz arenite, with massive dissolution first of plagioclase and subsequently K-feldspar. As the bulk composition changes, the suite of clay minerals changes from kaolinite-dominated to illite-dominated, suite of clay minerals changes from kaolinite-dominated to illite-dominated, typically accompanied by a pronounced decrease in permeability. The Gulf of Mexico sandstones are also initially arkoses. Their composition, however, evolves toward a mixture of quartz and compositionally pure albite. Kaolinite remains the dominant authigenic clay within the sandstones; however detrital clays change from a Na-rich, smectitic mixed layer clay to a K-rich, illitic mixed layer clay. The contrasting diagenetic pathways result from differing mineralogy in the clastic section. The smectite-rich mudstones in the Gulf of Mexico provide a powerful sink for potassium and source of sodium. The resulting low potassium activity results in K-feldspar dissolution; it also prevents illite formation, while high sodium activity stabilizes albite. The Middle Jurassic clastic section in northwest Europe contains relatively little smectite, thus lacks the potassium sink and sodium source. Sodium activity is low, so plagioclases preferentially dissolve. K-feldspars also dissolve, but the potassium here is available for illite formation.

  8. Navajo Nation expands family planning services.

    PubMed

    Haws, J; Crawford, G

    1996-01-01

    An AVSC training program, conducted in cooperation with the Navajo Nation Family Planning Corporation (NNFPC), has the potential to profoundly affect sterilization provision and acceptability on the Navajo Nation reservation. AVSC trained a family physician from the Northern Navajo Medical Center (New Mexico) in the no-scalpel vasectomy technique. This physician expects to provide 30 such sterilizations in the one-year period following the training and is preparing to teach reservation physicians from other health centers to perform the procedure. In addition, a joint AVSC-NNFPC course on sterilization counseling was presented to 30 nursing staff from the New Mexico Center. Central to this training was consideration of the obstacles to sterilization acceptance posed by Navajo cultural beliefs. Sensitivity to some women's desire to keep the procedure private, due to concerns their husbands will abandon them if they can no longer bear children, and to the potential need to include mothers and grandmothers in counseling sessions, is required. Also salient for female counselors and nurses are cultural taboos against a woman discussing sexual matters with a man with whom she is not intimate. In late 1996, AVSC will provide a sterilization counseling update for all NNFPC counselors working at centers throughout the four-state reservation. PMID:12347635

  9. Ramah Navajo Radio and Cultural Preservation

    ERIC Educational Resources Information Center

    Rada, Stephen A.

    1978-01-01

    The Ramah leadership, aware of their isolation, the lack of economic opportunity, the Navajo's poor self image as a people, and the almost total absence of any sense of community, built a radio station. This study, conducted over three and a half years after the station was put into operation, is a preliminary assessment of its impact upon the…

  10. Navajo Caregivers' Perceptions of Early Intervention Services.

    ERIC Educational Resources Information Center

    Applequist, Karen L.; Bailey, Donald B., Jr.

    2000-01-01

    This study investigated 52 Navajo family caregiver perceptions about early intervention services and supplemental information was gathered from 15 early interventionists identified by caregivers. Overall, caregivers were satisfied with services. Caregivers' perceptions of program family-centeredness had a strong positive relationship with…

  11. Determinants of Blood Pressure in Navajo Adolescents.

    ERIC Educational Resources Information Center

    Coulehan, John L.; And Others

    1990-01-01

    Among 580 Navajo adolescents, 11.1 percent of males and 1.6 percent of females had high blood pressure. Blood pressure was related to age in males and to body mass index in females but was not related to level of acculturation or traditionality. Contains 17 references. (SV)

  12. Origins of relief along contacts between eolian sandstones and overlying marine strata

    SciTech Connect

    Eschner, T.B.; Kocurek, G.

    1988-08-01

    Origins of large-scale relief along eolian-marine unit contacts, which form significant stratigraphic traps for hydrocarbons, can be recognized as inherited, reworked, and/or erosional. The Permian Rotliegende-Weissliegende Sandstone and Yellow Sands of Europe may best exemplify inherited relief in that dunes are preserved largely intact. Reworked relief, which shows significant destruction of original dune topography but with remnants of the bedforms preserved, is shown by relict Holocene dunes of coastal Australia, the Jurassic Entrada Sandstone of the San Juan basin, and the Pennsylvanian-Permian Minnelusa Formation of Wyoming. Erosional relief results from post-eolian processes and is exemplified by the Jurassic Entrada Sandstone of northeastern Utah. 11 figs., 1 tab.

  13. Jurassic Park: Adventure in Learning.

    ERIC Educational Resources Information Center

    Shams, Marcia; Boteler, Trina

    1993-01-01

    Describes using the movie "Jurassic Park" as a foundation for a middle school interdisciplinary unit involving science, math, language arts, history, and geography. Suggested books and activities are presented. (PR)

  14. Map showing ground-water conditions in the Kaibito and Tuba City areas, Coconino and Navajo counties, Arizona, 1978

    USGS Publications Warehouse

    Farrar, C.D.

    1978-01-01

    The Kaibito and Tuba City areas include about 2,500 square miles in north-central Arizona. Ground water is obtained from the N aquifer and from alluvium. The N aquifer consists of Navajo Sandstone, Kayenta Formation, Moenave Formation, and the Lukachukai Member of the Wingate Sandstone. The main source of ground water is the Navajo Sandstone. Ground-water development has been slight in the areas. In 1977 the estimated ground-water withdrawals were about 350 acre-feet in the Kaibito area and 650 acre-feet in the Tuba City area. Water levels ranged from flowing at the land surface to 1,360 feet below the land surface. The chemical quality of the water in the N aquifer does not vary greatly in the areas. Dissolved-solids concentrations in the water range from 101 to 669 milligrams per liter but generally are less than 300 milligrams per liter. Along some of the valleys in the Kaibito and Tuba City areas, the alluvium yields water to many shallow dug wells. The water levels generally are from 5 to 15 feet below the land surface. Dissolved-solids concentrations in water from the alluvium usually are less than 600 milligrams per liter. Information shown on the map (scale 1:125,000) includes depth to water, altitude of the water level, and specific conductance and fluoride concentrations. (Woodard-USGS)

  15. Deformation of Aztec Sandstone at Valley of Fire of Nevada: failure modes, sequence of deformation, structural products and their interplay with paleo fluids

    NASA Astrophysics Data System (ADS)

    Aydin, A.

    2014-12-01

    The Valley of Fire State Park, 60 km NE of Las Vegas, is a beacon of knowledge for deformation of Aztec Sandstone, a cross-bedded quartz arenite deposited in the Aztec-Navajo-Nugget erg in early Jurassic. It displays great diversity of physical properties, different localization types and micromechanics. The two deformation episodes, the Sevier folding & thrusting and the Basin & Range extension affected the area. The appearance of compaction bands marks the earliest deformation structure and their distribution, orientation, and dimension are controlled by the depositional architecture and loading. The earliest shear structures in the area are the Muddy Mountain, Summit, and Willow Tank thrusts and numerous small-scale bed-parallel faults. They altogether produced several kilometers of E-SE transport and shortening in the late Cretaceous and display numerous shear bands in its damage zone within the Aztec Sandstone. Shear bands also occur along dune boundaries and cross-bed interfaces. These observations indicate that the early deformation of the sandstone was accommodated by strain localization with various kinematics. The younger generation of faults in the area is of mid-Miocene age, and crops out pervasively. It includes a series of small offset normal faults (less than a few ten meters) which can be identified at steep cliff faces. These faults are highly segmented and are surrounded by a dense population of splay fractures. A large number of these splays were later sheared sequentially resulting in a well-defined network of left- and right-lateral strike-slip faults with slip magnitudes up to a few kilometers in the Park. The formation mechanisms of both the normal and strike-slip faults can be characterized as the sliding along planes of initial weaknesses and the accompanying cataclastic deformation. Some of the initial weak planes are associated with the depositional elements such as interdune boundaries and cross-bed interfaces while others are joint

  16. Middle Jurassic sand reservoirs of Tazovskoe field (West Siberia)

    NASA Astrophysics Data System (ADS)

    Kurasov, I. A.

    2012-12-01

    Perspectives of Tazovskoe field Jurassic strata development are associated with lithological and mineralogical characteristics of reservoirs, which are the main reserve of the region, because of the high rate of depletion of the most prolific Cenomanian gas pools. Tazovskoye field is multibedded and is unique in terms of hydrocarbon reserves. Middle Jurassic strata occur everywhere and are represented by rocks of the Tyumenskaya formation, comprising layers J2 - J5. The producing horizons are composed of sandstones, sandy siltstones, cemented by shaly-carbonate cement mass. According to laboratory data, the Jurassic reservoirs are characterized by a wide range of porosity (up to 22.5%) and mainly low permeability (up to 2 mD), except for a few samples of J3 reservoir with permeability up to 100-150 mD. Test objects were the core samples taken from 7 intervals of the well T-83 and logging data from 4 intervals of wells 73, 93 in the Tazovskoye field. Depth and core recovery from T-83 well of the Tazovskoye field are shown in Table 1. Total linear core recovery from the Jurassic strata was 79.4 m. Late Bajocian-Bathonian alluvial-lacustrine strata compose the first regressive cycle of sedimentation in the Tazovskoye field. They are represented by alternating thin sandy, siltstone-sandy, siltstone, shaly-siltstone, siltstone-shaly, and shaly rocks with coal interbeds. They include three main productive formations: J2, J3 and J4. Above in the vertical section, the Upper Jurassic rocks occur, while lower, basal strata of the Callovian stage overlay them with a distinct unconformity. In the Upper Jurassic time, the main transgression phase of the Jurassic period occurred over the whole territory of the Western Siberia. These strata are built by non-uniform alternating sandstones, siltstones and shales with coal interbeds of the continental genesis (alluvial-lacustrine); The reservoirs contain cyclites that as a rule have binary structure, less often - ternary structure

  17. Reclaiming Indigenous Intellectual, Political, and Geographic Space: A Path for Navajo Nationhood

    ERIC Educational Resources Information Center

    Lee, Lloyd L.

    2008-01-01

    For millennia, Navajo society was self-sufficient. After 1863, beginning with Kit Carson's murderous rampage among the Navajo and the subsequent removal to the Bosque Redondo reservation, Navajo nationhood changed. Navajo society began a slow transformation away from the distinct Dine way of life. In the twentieth century Navajo nationalism was…

  18. The Navajo Way of Life: A Resource Unit with Activities for Grades 4-6.

    ERIC Educational Resources Information Center

    Cordova, Dahlia

    A resource unit on the Navajo way of life, for grades 4-6, contains sections on Navajo history, art, and crafts, homes, music, poetry and games; Navajo and Pueblo cookery (including recipes); traditional Navajo dress, ceremony and legends; and successful Navajos, past and present. Sections include text, vocabulary words, drawings, maps, and…

  19. Navajo Participation in Labor Unions. Lake Powell Research Project Bulletin Number 15, December 1975.

    ERIC Educational Resources Information Center

    Robbins, Lynn A.

    Navajo participation in labor unions and Navajo labor relations have undergone rapid and fundamental changes since the development of industry around Lake Powell and on Black Mesa. Early attempts to unionize Navajo workers met with stiff resistance from employees and the Navajo Tribal Council. Union entry into the Navajo Reservation was viewed as…

  20. Language Learning in the American Southwestern Borderlands: Navajo Speakers and Their Transition to Academic English Literacy.

    ERIC Educational Resources Information Center

    Dyc, Gloria

    2002-01-01

    The Navajo Nation wants a 2-year Navajo language requirement for regional colleges. At the same time, literacy in academic English is required for Navajo students wishing to enter the sciences, medicine, and law. The difficulties students face as they make the transition from English to Navajo and from Navajo to English are described. Four…

  1. JURASSIC Retrieval Processing

    NASA Astrophysics Data System (ADS)

    Blank, J.; Ungermann, J.; Guggenmoser, T.; Kaufmann, M.; Riese, M.

    2012-04-01

    The Gimballed Limb Observer for Radiance Imaging in the Atmosphere (GLORIA) is an aircraft based infrared limb-sounder. This presentation will give an overview of the retrieval techniques used for the analysis of data produced by the GLORIA instrument. For data processing, the JUelich RApid Spectral SImulation Code 2 (JURASSIC2) was developed. It consists of a set of programs to retrieve atmospheric profiles from GLORIA measurements. The GLORIA Michelson interferometer can run with a wide range of parameters. In the dynamics mode, spectra are generate with a medium spectral and a very high temporal and spatial resolution. Each sample can contain thousands of spectral lines for each contributing trace gas. In the JURASSIC retrieval code this is handled by using a radiative transport model based on the Emissivity Growth Approximation. Deciding which samples should be included in the retrieval is a non-trivial task and requires specific domain knowledge. To ease this problem we developed an automatic selection program by analysing the Shannon information content. By taking into account data for all relevant trace gases and instrument effects, optimal integrated spectral windows are computed. This includes considerations for cross-influence of trace gases, which has non-obvious consequence for the contribution of spectral samples. We developed methods to assess the influence of spectral windows on the retrieval. While we can not exhaustively search the whole range of possible spectral sample combinations, it is possible to optimize information content using a genetic algorithm. The GLORIA instrument is mounted with a viewing direction perpendicular to the flight direction. A gimbal frame makes it possible to move the instrument 45° to both direction. By flying on a circular path, it is possible to generate images of an area of interest from a wide range of angles. These can be analyzed in a 3D-tomographic fashion, which yields superior spatial resolution along line of

  2. Reevaluation of upper Jurassic Morrison Formation, Western Interior

    SciTech Connect

    Mantzios, C.

    1989-03-01

    Comparison of the Brushy Basin member of the Upper Jurassic Morrison Formation in the Colorado Plateau with the Upper Jurassic-Lower Cretaceous Morrison-Cloverly sequence in the Bighorn basin, Wyoming, shows great similarities in their depositional environments and stratigraphy. The lower Brushy Basin member is a fluvial deposit composed of channel sandstones and overbank mudstones which display a great number of pedogenic features. Similar depositional setting has been observed in the Morrison Formation in the Bighorn basin, Wyoming, where pedogenic features suggest a distal floodplain setting with low-sinuosity channels cutting through. In both localities the dominant clay mineral is illite. The upper Brushy Basin member in the Colorado Plateau is composed mostly of gray and purpose mudstones rich in montmorillonite. Devitrified tuff beds and bentonite occur in certain levels throughout the unit. Pedogenic features are not conspicuously developed. The Lower Cretaceous Clovery Formation in the Bighorn basin, Wyoming, is strikingly similar in terms of lithological aspects. The depositional environment is interpreted in both localities as a playa deposit. A great variety of nodules is present such as silcretes, septaria, and silica-carbonate nodules. Radiometric dating of bentonites in central Utah revealed that the upper Brushy Basin member is Early Cretaceous in age. Field and geochemical data support these conclusions and aid the understanding of the exact nature of the depositional basin, environments, stratigraphy, and paleotectonics of the Upper Jurassic-Lower Cretaceous interval in the Western Interior.

  3. Hydrologic analyses in support of the Navajo Generating Station–Kayenta Mine Complex environmental impact statement

    USGS Publications Warehouse

    Leake, Stanley A.; Macy, Jamie P.; Truini, Margot

    2016-01-01

    IntroductionThe U.S. Department of Interior’s Bureau of Reclamation, Lower Colorado Region (Reclamation) is preparing an environmental impact statement (EIS) for the Navajo Generating Station-Kayenta Mine Complex Project (NGS-KMC Project). The proposed project involves various Federal approvals that would facilitate continued operation of the Navajo Generating Station (NGS) from December 23, 2019 through 2044, and continued operation of the Kayenta Mine and support facilities (collectively called the Kayenta Mine Complex, or KMC) to supply coal to the NGS for this operational period. The EIS will consider several project alternatives that are likely to produce different effects on the Navajo (N) aquifer; the N aquifer is the principal water resource in the Black Mesa area used by the Navajo Nation, Hopi Tribe, and Peabody Western Coal Company (PWCC).The N aquifer is composed of three hydraulically connected formations—the Navajo Sandstone, the Kayenta Formation, and the Lukachukai Member of the Wingate Sandstone—that function as a single aquifer. The N aquifer is confined under most of Black Mesa, and the overlying stratigraphy limits recharge to this part of the aquifer. The N aquifer is unconfined in areas surrounding Black Mesa, and most recharge occurs where the Navajo Sandstone is exposed in the area near Shonto, Arizona. Overlying the N aquifer is the D aquifer, which includes the Dakota Sandstone, Morrison Formation, Entrada Sandstone, and Carmel Formation. The aquifer is named for the Dakota Sandstone, which is the primary water-bearing unit.The NGS is located near Page, Arizona on the Navajo Nation. The KMC, which delivers coal to NGS by way of a dedicated electric railroad, is located approximately 83 miles southeast of NGS (about 125 miles northeast of Flagstaff, Arizona). The Kayenta Mine permit area is located on about 44,073 acres of land leased within the boundaries of the Hopi and Navajo Indian Reservations. KMC has been conducting mining and

  4. Lung cancer among Navajo uranium miners

    SciTech Connect

    Gottlieb, L.S.; Husen, L.A.

    1982-04-01

    Lung cancer has been a rare disease among the Indians of the southwestern United States. However, the advent of uranium mining in the area has been associated with an increased incidence of lung cancer among Navajo uranium miners. This study centers on Navajo men with lung cancer who were admitted to the hospital from February 1965 to May 1979. Of a total of 17 patients with lung cancer, 16 were uranium miners, and one was a nonminer. The mean value of cumulative radon exposure for this group was 1139.5 working level months (WLMs). The predominant cancer type was the small cell undifferentiated category (62.5 percent). The low frequency of cigarette smoking in this group supports the view that radiation is the primary cause of lung cancer among uranium miners and that cigarette smoking acts as a promoting agent.

  5. Middle Jurassic incised valley fill (eolian/estuarine) and nearshore marine petroleum reservoirs, Powder River basin

    SciTech Connect

    Ahlbrandt, T.S.; Fox, J.E.

    1997-07-01

    Paleovalleys incised into the Triassic Spearfish Formation (Chugwater equivalent) are filled with a vertical sequence of eolian, estuarine, and marine sandstones of the Middle Jurassic (Bathonian age) Canyon Springs Sandstone Member of the Sundance Formation. An outcrop exemplifying this is located at Red Canyon in the southern Black Hills, Fall River County, South Dakota. These paleovalleys locally have more than 300 ft of relief and are as much as several miles wide. Because they slope in a westerly direction, and Jurassic seas transgressed into the area from the west there was greater marine-influence and more stratigraphic complexity in the subsurface, to the west, as compared to the Black Hills outcrops. In the subsurface two distinctive reservoir sandstone beds within the Canyon Springs Sandstone Member fill the paleovalleys. These are the eolian lower Canyon Springs unit (LCS) and the estuarine upper Canyon Springs unit (UCS), separated by the marine {open_quotes}Limestone Marker{close_quotes} and estuarine {open_quotes}Brown Shale{close_quotes}. The LCS and UCS contain significant proven hydrocarbon reservoirs in Wyoming (about 500 MMBO in-place in 9 fields, 188 MMBO produced through 1993) and are prospective in western South Dakota, western Nebraska and northern Colorado. Also prospective is the Callovian-age Hulett Sandstone Member which consists of multiple prograding shoreface to foreshore parasequences, as interpreted from the Red Canyon locality. Petrographic, outcrop and subsurface studies demonstrate the viability of both the Canyon Springs Sandstone and Hulett Sandstone members as superior hydrocarbon reservoirs in both stratigraphic and structural traps. Examples of fields with hydrocarbon production from the Canyon Springs in paleovalleys include Lance Creek field (56 MMBO produced) and the more recently discovered Red Bird field (300 MBO produced), both in Niobrara County, Wyoming.

  6. Incidence and prevalence of Parkinson's disease among Navajo people living in the Navajo nation.

    PubMed

    Gordon, Paul H; Mehal, Jason M; Holman, Robert C; Bartholomew, Michael L; Cheek, James E; Rowland, Andrew S

    2015-04-15

    Parkinson's disease (PD) is largely unstudied among American Indians. Unique populations might harbor clues to elusive causes. We describe the incidence and prevalence of PD among Navajo people residing in the Navajo Nation, home to the largest American Indian tribe in the United States. We analyzed 2001-2011 inpatient and outpatient visit data for Navajo people obtained from the Indian Health Service, which provides health care to American Indian people living on the Navajo Reservation. Cases were defined by at least two inpatient or outpatient visits with the diagnosis of PD. Crude and age-adjusted incidence and prevalence rates were calculated overall as well as by age, sex, region of residence, and time period. Five hundred twenty-four Navajo people with median age-at-onset of 74.0 years were diagnosed with PD during the study period, yielding an average annual crude incidence rate of 22.5/100,000. Age-specific incidence was 232.0 for patients 65 years of age or older and 302.0 for 80 years of age or older. Age-adjusted incidence was 35.9 overall (238.1 for ≥65 years), was higher in men than in women (47.5 vs. 27.7; P<0.001), varied by region (P=0.03), and was similar between time periods (2002-2004 vs. 2009-2011). The age-adjusted point prevalence rate was 261.0. The rate of PD among Navajo People appears to be as high as or higher than rates reported in many other populations. Rates increased to the highest age group, consistent with population-based studies. Further investigation is warranted to examine risk factors for PD in this remote population. PMID:25649219

  7. Stochastic reconstruction of sandstones

    PubMed

    Manwart; Torquato; Hilfer

    2000-07-01

    A simulated annealing algorithm is employed to generate a stochastic model for a Berea sandstone and a Fontainebleau sandstone, with each a prescribed two-point probability function, lineal-path function, and "pore size" distribution function, respectively. We find that the temperature decrease of the annealing has to be rather quick to yield isotropic and percolating configurations. A comparison of simple morphological quantities indicates good agreement between the reconstructions and the original sandstones. Also, the mean survival time of a random walker in the pore space is reproduced with good accuracy. However, a more detailed investigation by means of local porosity theory shows that there may be significant differences of the geometrical connectivity between the reconstructed and the experimental samples. PMID:11088546

  8. Frisco City sand: New Jurassic reservoir in southwest Alabama

    SciTech Connect

    Mann, S.D.; Mink, R.M.; Bearden, B.L. ); Schneeflock, R.D. Jr. )

    1989-09-01

    The first commercial production of hydrocarbons from the Jurassic Haynesville Formation in southwestern Alabama was from the Frisco City field. The field currently produces 57.8{degree} API gravity oil on 160-ac well spacing from a depth of approximately 12,000 ft. Perforations are in the Frisco City sand interval, in the lower part of the Haynesville Formation. Average porosity is 15% and average permeability is 45 md. Currently, the field has two producing wells with cumulative production of over 138,876 bbl of oil and 213,144 mcf of gas. The hydrocarbon trap in the Frisco City field is a combination structural-stratigraphic trap. The Frisco City sand reservoir is located on a faulted anticline. The stratigraphic trap is produced by a permeability barrier near the crest of the structure and termination against a basement high. The lower part of the Haynesville Formation in this area is comprised of (in ascending order) the Buckner Anhydrite Member, the Frisco City sand, and interbedded shale and anhydrite. Sandstones of the Frisco City sand interval were deposited in a shallow marine setting and have a sheetlike morphology. The sandstones are poorly to moderately sorted, angular to rounded arkose, and contain angular to rounded pebbles. The sandstones are interbedded with thin, sandy, mudstones that contribute, along with patchy carbonate and anhydrite cement, to considerable reservoir heterogeneity. Porosity is predominantly primary intergranular with a small amount of framework grain dissolution and decementation.

  9. Compactional deformation bands in Wingate Sandstone; additional evidence of an impact origin for Upheaval Dome, Utah

    NASA Astrophysics Data System (ADS)

    Okubo, Chris H.; Schultz, Richard A.

    2007-04-01

    Field and microstructural observations from Upheaval Dome, in Canyonlands National Park, Utah, show that inelastic strain of the Wingate Sandstone is localized along compactional deformation bands. These bands are tabular discontinuities (< 0.5 cm thick) that accommodate inelastic shear and compaction of inter-granular volume. Measurements of porosity and grain size from non-deformed samples are used to define a set of capped strength envelopes for the Wingate Sandstone. These strength envelopes reveal that compactional deformation bands require at least ca. 0.7 GPa (and potentially more than 2.3 GPa) of effective mean stress in order to nucleate within this sandstone. We find that the most plausible geologic process capable of generating these required magnitudes of mean stress is a meteoritic impact. Therefore the compactional deformation bands observed within the Wingate Sandstone are additional evidence of an impact event at Upheaval Dome and support a post-Wingate (post-Early Jurassic) age for this impact.

  10. Controls on the variability of net infiltration to desert sandstone

    USGS Publications Warehouse

    Heilweil, V.M.; McKinney, T.S.; Zhdanov, M.S.; Watt, D.E.

    2007-01-01

    As populations grow in and climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates. Copyright 2007 by the American Geophysical Union.

  11. Controls on the variability of net infiltration to desert sandstone

    NASA Astrophysics Data System (ADS)

    Heilweil, Victor M.; McKinney, Tim S.; Zhdanov, Michael S.; Watt, Dennis E.

    2007-07-01

    As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates.

  12. Laughter: The Navajo Way. Humorous Stories of the People (in Navajo and English) Volume One.

    ERIC Educational Resources Information Center

    Wilson, Alan; Dennison, Gene

    This book has been prepared for the use of teachers, ethnologists, linguists, Indian studies scholars, language students and those who have an interest in the languages and cultures of the earlier inhabitants of this continent. The stories reflect the Navajo love for and genius with words and humor. Most of the humor represented is of three basic…

  13. Navajo Youth and Anglo Racism: Cultural Integrity and Resistance.

    ERIC Educational Resources Information Center

    Deyhle, Donna

    1995-01-01

    Results of a 10-year ethnographic study of Navajo youth show that racial and cultural differences intertwine with power relations and that Navajos' success or failure in school is part of the process of racial conflict. Subject to discrimination in workplaces and curricula, they are more academically successful when more secure in their…

  14. "Dine Bikeya": Teaching about Navajo Citizenship and Sovereignty

    ERIC Educational Resources Information Center

    Washington, Elizabeth Yeager; van Hover, Stephanie

    2011-01-01

    The Navajo Nation, comprising the largest land area allocated mainly to a Native American jurisdiction in the United States, offers a unique opportunity to enhance students' understandings of citizenship rights and sovereignty. For example, what does sovereignty mean on the reservation? What is the relationship between the Navajo Nation and the…

  15. The Impact on Navajo Mothers Becoming Special Education Teachers.

    ERIC Educational Resources Information Center

    Prater, Greg; And Others

    This paper discusses the impact that participating in a teacher preparation program has had on Navajo mothers. Mothers play a very central role in Navajo culture, and such impacts, both positive and negative, are important not only to program participants, but also to those working in Indian communities. Informal surveys were conducted with 20…

  16. Depo-provera associated with weight gain in Navajo women.

    PubMed

    Espey, E; Steinhart, J; Ogburn, T; Qualls, C

    2000-08-01

    Depo-medroxyprogesterone acetate (DMPA) is an increasingly popular contraceptive choice among Navajo women. Weight gain is cited as a common side effect and major reason for discontinuation of DMPA. No controlled trials have evaluated the association between weight gain and DMPA in Navajo women. We aimed to clarify whether DMPA is associated with weight gain in Navajo women and to quantify the magnitude of weight gain. A cohort of 172 Navajo women who had used DMPA continuously for one or 2 years comprised the study group. A cohort of 134 Navajo women who used a non-progestin method or no method over 1 or 2 years comprised the comparison group. Initial weight, one-year weight and 2-year weights were recorded for all patients. Study subjects gained a mean of 6 pounds over one year and 11 pounds over 2 years relative to the comparison group (p < 0.001) after controlling for possible confounding variables including age, parity and initial weight. Use of DMPA is associated with significant weight gain in Navajo women. This weight gain is greater than that reported in previous uncontrolled studies in non-Navajo populations. This information should be utilized in counseling Navajo women about the side effects of DMPA. PMID:11102587

  17. Description and Bibliography, Revised 1975. Navajo Reading Study.

    ERIC Educational Resources Information Center

    Spolsky, Bernard, Comp.; And Others

    Begun in 1969, the Navajo Reading Study investigated the feasibility and effect of teaching Navajo children to read their own language before they start learning to read English. Conducted at the University of New Mexico and supported by grants from the Ford Foundation and contracts with the Bureau of Indian Affairs and the U.S. Office of…

  18. Navajo Mothers and Daughters: Schools, Jobs, and the Family.

    ERIC Educational Resources Information Center

    Deyhle, Donna; Margonis, Frank

    1995-01-01

    Studies Navajo women's family orientation in reservation society and its conflict with contemporary educational practice and the work world, especially in the city. The focus on individualistic lifestyle and adoption of middle-class values accounts for the inability of schools to meet Navajo women's needs. (MMU)

  19. Mask of Black God: The Pleiades in Navajo Cosmology

    ERIC Educational Resources Information Center

    Schulz, Teresa M.

    2005-01-01

    One Navajo legend attributes the creation of the primary stars and constellations to Black God. Today, a famous star cluster--the Pleiades--often appears on the traditional mask worn by chanters impersonating Black God during special ceremonies. In this case study, students learn about the Pleiades in Navajo cosmology while honing their…

  20. The Effects of Sociocultural Factors on the Navajo Literacy Environment.

    ERIC Educational Resources Information Center

    Greene, Diane C.

    This paper describes an ethnographic study of school and community characteristics affecting the literacy development of Navajo children, and provides an overview of sociocultural factors in the literacy environment of one Navajo community. The researcher was a principal at Pinon Public School District #4 in Pinon, Arizona, in the heart of the…

  1. Navajo Archaeologist Is Not an Oxymoron: A Tribal Archaeologist's Experience

    ERIC Educational Resources Information Center

    Two Bears, Davina R.

    2006-01-01

    Many Navajos, or Dines, and Native American people in general, are archaeologists or are becoming archaeologists. The distinction between "Native Americans" and "archaeologists" in academia, or elsewhere, is no longer accurate. This fact should not come as such a surprise. As the epigraph, a quote by Richard Begay, demonstrates, Navajo people, for…

  2. Navajo Area Health and Physical Education Curriculum Guidelines.

    ERIC Educational Resources Information Center

    Tomah, Kent; And Others

    Based on health education needs of Navajo children as established by the Navajo Area health and physical education committees, this curriculum guideline for health and physical education is delineated into three phases reflecting emphasis of instructional techniques (introductory, exploration/extended learning, widened learning) and three levels…

  3. Socializing English-Speaking Navajo Children to Storytelling

    ERIC Educational Resources Information Center

    Vining, Christine B.

    2015-01-01

    Understanding how young children are socialized to the process and products of storytelling as part of everyday family life is important for language and literacy instruction. A language socialization framework was used to understand storytelling practices on the Navajo Nation. This study examined how three young English-speaking Navajo children,…

  4. The Navajo Agricultural Projects Industry: Subsistence Farming to Corporate Agribusiness.

    ERIC Educational Resources Information Center

    Barry, Tom

    1979-01-01

    Originally designed to create small farms for individual Navajos, the irrigation project has grown into a single 110,000-acre corporate agribusiness, the land's management has fallen out of the grasp of individual Navajos, and the idea of subsistence farming has been plowed under for the planting of major money-making crops. (NQ)

  5. Right after Sundown: Teaching Stories of the Navajos.

    ERIC Educational Resources Information Center

    Mabery, Marilyne Virginia

    Understanding of the traditional Navajo world view and philosophy is ultimately centered on their origin story of emergence into the present world. All stories stem from this basic one. This collection of 12 Navajo stories includes origin stories, coyote stories, and a fairly recent one that describes a recognizable place. In the Anglo sense,…

  6. Assessing Navajo Psychological and Educational Needs in New Mexico.

    ERIC Educational Resources Information Center

    Jordan, Elaine; French, Laurence; Tempest, Phyllis

    1997-01-01

    Examines issues impacting identification and evaluation of Navajo children at risk: acculturation variables creating culture conflict; mental health issues for Navajo communities; environmental, emotional, and physical health factors contributing to underachievement; testing bias issues resulting in inappropriate educational placement decisions;…

  7. The Navajo Student and the Tennessee Self Concept.

    ERIC Educational Resources Information Center

    Tempest, Phyllis

    1985-01-01

    Using Tennessee Self Concept, the follow-up study evaluated 33 Navajo eighth graders who were part of a seventh grade daily prescriptive intervention program and were part of a previous study of 222 Navajo fifth graders given tests assessing their strength and needs so that an appropriate curriculum could be adopted. (NEC)

  8. Health and health services among the Navajo Indians.

    PubMed

    Haraldson, S S

    1988-01-01

    The Navajo are the largest Indian tribe in the continental U.S. with a population in 1986 estimated at 171,097. The Navajo Nation (Reservation) is located along the borders where Arizona, New Mexico, Colorado and Utah meet. Social and economic changes have accrued among the Navajo at a rapid rate during this century. At present, revenues are derived from oil, coal and uranium and from federal grants and contracts. High unemployment rates have been a major problem among the Navajo. This article reviews health, disease and health care among the present day Navajo. Mortality rates from accidents and suicide are disproportionately high and have as their causes longstanding social and behavioral problems. Although there has been a sharp decline in morbidity and mortality from infectious diseases, there are still major environmental health problems. PMID:3068261

  9. Cultural identity, explanatory style, and depression in Navajo adolescents.

    PubMed

    Rieckmann, Traci R; Wadsworth, Martha E; Deyhle, Donna

    2004-11-01

    This study investigated the interrelationships among cultural identity, explanatory style, and depression in Navajo adolescents. A total of 332 (197 female, 135 male) Navajo adolescents completed 7 self-report measures. These data were used to create, via structural equation modeling, a series of factor models and full structural models. Analyses indicated that current factor structures for explanatory style and depression are adequate for use with Navajo adolescents. Increased control and predictability and limited duration of stressful encounters were both predictive of decreased symptoms of depression. Higher levels of Navajo cultural identity had a modest effect in terms of reducing depression. Other factors, such as perceived discrimination and urban/reservation domicile, are important to study to provide an increased understanding of depression among Navajo adolescents. PMID:15554799

  10. Petrography and geologic significance of Upper Jurassic rocks dredged near Pribilof Islands, southern Bering Sea continental shelf

    SciTech Connect

    Vallier, T.L.; Underwood, M.B.; Jones, D.L.; Gardner, J.V.

    1980-06-01

    Upper Jurassic (Kimmeridgian) sandstone and siltstone dredged from a probable submerged marine terrace near St. George Island (Pribilof Islands) in the southern Bering Sea are correlative with the upper part of the Naknek Formation exposed on the Alaska Peninsula and with rocks dredged from the continental slope. The rocks have higher percentages of volcanic components than those of the Naknek Formation collected from the Alaska Peninsula. This discovery increases the known regional extent of Upper Jurassic rocks and suggests that they underlie a large part of the continental margin in the St. George Basin region of the southern Bering Sea. 3 figures, 1 table.

  11. Diné (Navajo) Ethno- and Archaeoastronomy

    NASA Astrophysics Data System (ADS)

    Chamberlain, Von Del

    The Navajo (Diné) are an Athabascan-speaking people who migrated from the far northwest of America into the desert southwest where they became the largest surviving Native American culture. Three words portray Diné philosophy - beauty, harmony, and balance. Their traditions are rich with astronomical symbolism found in literature, ceremony, iconography, artifacts, rock art, and the sacred landscape. This chapter summarizes Diné astronomical traditions, identification of stars known to be important to the Diné, and how these are depicted on artifacts and rock art.

  12. Collapsing the Fear of Mathematics: A Study of the Effects of Navajo Culture on Navajo Student Performance in Mathematics

    ERIC Educational Resources Information Center

    Fowler, Henry H.

    2010-01-01

    Collapsing the Fear of Mathematics: A Study of the Effects of Navajo Culture on Navajo Student Performance in Mathematics by Henry H Fowler Abstract American schools are in a state of "mediocrity" because of the low expectations in math (National Commission on Excellence in Education, 1983; No Child Left Behind Act of 2001; Duncan, 2009).…

  13. Navajo Culture and Family Influences on Academic Success: Traditionalism Is Not a Significant Predictor of Achievement among Navajo Youth.

    ERIC Educational Resources Information Center

    Willeto, Angela A. A.

    1999-01-01

    A study of 451 Navajo youths attending 11 high schools in the Navajo Nation found no relationship between their academic achievement and their cultural attachments and practices. Families modestly influenced educational outcomes, but being female was a stronger predictor of academic success. An appendix describes study variables. (Contains 42…

  14. From a Place Deep inside: Culturally Appropriate Curriculum as the Embodiment of Navajo-ness in Classroom Pedagogy

    ERIC Educational Resources Information Center

    Yazzie-Mintz, Tarajean

    2007-01-01

    Three Navajo teachers' conceptions of culturally appropriate curriculum and pedagogy highlight the benefits of reflective practice within different educational and school contexts. Each teacher provides a way of thinking about culturally appropriate curriculum, and its implementation in classroom practice for different Navajo students. The ways in…

  15. Area Health Education Center of the Navajo Health Authority to Establish the Navajo Center for Health Professions Education.

    ERIC Educational Resources Information Center

    Navajo Health Authority, Window Rock, AZ.

    The Area Health Education Center (AHEC) is designed to provide educational opportunities in health and allied fields and to improve health care for the Navajo people and other Indians in the region that includes and immediately surrounds the Navajo Indian Reservation. As prime contractor, the University of New Meixco School of Medicine will…

  16. Looking after the Land: The Navajo Dryland Environments Laboratory Researches the Environmental Needs of the Navajo Nation.

    ERIC Educational Resources Information Center

    Semken, Steven C.

    1992-01-01

    Describes the formation and operations of the Navajo Dryland Environments Laboratory (NDEL). NDEL, established by the Waste-Management Education and Research Consortium of New Mexico on the campus of Navajo Community College, focuses on environmental geology, hydrology, and resource management of the Colorado Plateau drylands. (DMM)

  17. A Framework for Engaging Navajo Women in Clean Energy Development through Applied Theatre

    ERIC Educational Resources Information Center

    Osnes, Beth; Manygoats, Adrian; Weitkamp, Lindsay

    2015-01-01

    Through applied theatre, Navajo women can participate in authoring a new story for how energy is mined, produced, developed, disseminated and used in the Navajo Nation. This article is an analysis of a creative process that was utilised with primarily Navajo women to create a Navajo Women's Energy Project (NWEP). The framework for this creative…

  18. Teaching Dine Language and Culture in Navajo Schools: Voices from the Community.

    ERIC Educational Resources Information Center

    Batchelder, Ann

    Since 1984 the Navajo Nation has mandated instruction in Navajo language and culture in K-12 schools within its boundaries. In 1998-99, a survey and follow-up interviews with 48 individuals in 20 Navajo communities examined community attitudes and beliefs about the value of Navajo language and culture studies and the extent to which the schools…

  19. 40 CFR 147.3400 - Navajo Indian lands-Class II wells.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained or inspected at the Navajo Nation... General of the Navajo Nation Pursuant to 40 CFR 145.24”, August 27, 2001. (2) “Statement of the Attorney... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust...

  20. 40 CFR 147.3400 - Navajo Indian lands-Class II wells.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained or inspected at the Navajo Nation... General of the Navajo Nation Pursuant to 40 CFR 145.24”, August 27, 2001. (2) “Statement of the Attorney... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust...

  1. 25 CFR 161.802 - How will the Navajo Nation recommend amendments to this part?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How will the Navajo Nation recommend amendments to this... Navajo Nation recommend amendments to this part? The Resources Committee will have final authority on behalf of the Navajo Nation to approve amendments to the Navajo Partitioned Lands grazing...

  2. 30 CFR 756.13 - Approval of the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Approval of the Navajo Nation's abandoned mine....13 Approval of the Navajo Nation's abandoned mine land plan. The Navajo Nation's Abandoned Mine Land... approved effective May 16, 1988. Copies of the approved program are available at: (a) The Navajo...

  3. 25 CFR 161.802 - How will the Navajo Nation recommend amendments to this part?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How will the Navajo Nation recommend amendments to this... Navajo Nation recommend amendments to this part? The Resources Committee will have final authority on behalf of the Navajo Nation to approve amendments to the Navajo Partitioned Lands grazing...

  4. 30 CFR 756.13 - Approval of the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Approval of the Navajo Nation's abandoned mine....13 Approval of the Navajo Nation's abandoned mine land plan. The Navajo Nation's Abandoned Mine Land... approved effective May 16, 1988. Copies of the approved program are available at: (a) The Navajo...

  5. The Physical, Environmental, and Intellectual Profile of the Fifth Grade Navajo.

    ERIC Educational Resources Information Center

    Tempest, Phyllis

    1987-01-01

    A random sample of 222 Navajo fifth graders from the Navajo Reservation were selected from eight schools and given an extensive battery of tests to determine intelligence, academic achievement, physical health, and environmental conditions. Results produced an average Navajo learning profile to which other Reservation Navajo students can be…

  6. Long term effects of CO2 on 3-D pore structure and 3-D phase distribution in reservoir sandstones from the Green River well (Utah, USA)

    NASA Astrophysics Data System (ADS)

    Barnhoorn, Auke; Kisoensingh, Shailesh

    2014-05-01

    Reservoir sandstones and cap rocks from the Green River area in Utah (USA) have been naturally exposed to CO2 fluids for hundreds of thousands of years, leading to compositional and microstructural alterations of the rocks. A 300m long section of this section of these Green river reservoir and cap rocks has been cored in 2012. Here, results of a high-resolution micro X-ray tomography study of a suite of samples from the well are reported detailing the 3D pore structure and phase distribution changes due to long term CO2 exposure. The reservoir sandstones from the Green River well (Utah) reveal the presence of various degrees of carbonate precipitation in the pores. Both reservoir sandstones (the shallower Entrada Formation and the deeper Navajo Formation) show variations in carbonate content and porosity structure. The Entrada sandstone exhibits widespread carbonate precipitation (up to 60% of infill of the original porosity), with the largest amount of carbonates at the boundary with the underlying Carmel cap rock. In an interval of a meter from the contact, carbonate precipitation decreases sharply till ~20%. The porosity is significantly reduced in the lowest 1 meter. The reduction in porosity lead to a reduction in pore connectivity and thereby permeability by the long-term CO2 exposure. On the other hand the Navajo sandstone shows predominantly only isolated spots of carbonate precipitation (up to 20% of the original porosity). Widespread carbonate precipitation is absent in the Navajo reservoir sandstone samples. Because carbonate precipitation is not present throughout, the large-scale permeability of the formation is likely not significantly affected by the CO2 exposure. The results show how the 3D distribution of the phases and the 3D shapes of the pores are affected by long term CO2 exposure and can be used as an example for potential changes to be expected in reservoir sandstones due to CO2 storage in future CO2 sequestration endeavours.

  7. Middle Jurassic strata link Wallowa, Olds Ferry, and Izee terranes in the accreted Blue Mountains island arc, northeastern Oregon

    SciTech Connect

    White, J.D.L. ); Vallier, T. ); Stanley, G.D. Jr. ); Ash, S.R. ); White, D.L.

    1992-08-01

    Middle Jurassic strata atop the Wallowa terrane in northeastern Oregon link the Wallowa, Izee, and Olds Ferry terranes as related elements of a single long-lived and complex oceanic feature, the Blue Mountains island arc. Middle Jurassic strata in the Wallowa terrane include a dacitic ash-flow deposit and contain fossil corals and bivalves of North American affinity. Plant fossils in fluvial sandstones support a Jurassic age and indicate a seasonal temperate climate. Corals in a transgressive sequence traditionally overlying the fluvial units are of Bajocian age and are closely related to endemic varieties of the Western Interior embayment. They are unlike Middle Jurassic corals in other Cordilleran terranes; their presence suggests that the Blue Mountains island arc first approached the North American craton at high paleolatitudes in Middle Jurassic time. The authors consider the Bajocian marine strata and underlying fluvial volcaniclastic units to be a basin-margin equivalent of the Izee terrane, a largely Middle Jurassic (Bajocian) succession of basinal volcaniclastic and volcanic rocks known to overlie the Olds Ferry and Baker terranes.

  8. A northwest trending, Jurassic Fold Nappe, northernmost Zacatecas, Mexico

    NASA Astrophysics Data System (ADS)

    Anderson, Thomas H.; McKee, James W.; Jones, Norris W.

    1991-04-01

    The Caopas, Rodeo, and Nazas formations exposed in the San Julián uplift of northern Zacatecas are distinguished principally on the basis of style and intensity of deformation; they are parts of the same early Mesozoic(?) volcanogenic suite. This suite was the source for overlying volcaniclastic conglomerate and sandstone (La Joya Formation) that appears transitional into succeeding Late Jurassic (Oxfordian?) Zuloaga Limestone. Deformation that was contemporaneous with the deposition of the lower part of the Zuloaga produced an asymmetrical northwest trending fold nappe that was driven southwestward. The massive quartz-porphyry core of the structure (Caopas Formation) moved somewhat independently of the encasing, more ductile rocks (Rodeo and Nazas formations). Phyllonite developed in the nose of the nappe; the upright limb was attenuated and ruptured. In zones where deformation due to the nappe-forming process was weaker, a gently dipping foliation, possibly related to an older episode of recumbent folding, is preserved. Orientation, age, and location of the nappe suggest that it is a manifestation of transpressional stress developed along the Mojave-Sonora megashear as left-lateral movement carried the Jurassic arc toward the southeast.

  9. Navajo coal and air quality in Shiprock, New Mexico

    USGS Publications Warehouse

    Bunnell, Joseph E.; Garcia, Linda V.

    2006-01-01

    Among the Navajo people, high levels of respiratory disease, such as asthma, exist in a population with low rates of cigarette smoking. Air quality outdoors and indoors affects respiratory health. Many Navajo Nation residents burn locally mined coal in their homes for heat, as coal is the most economical energy source. The U.S. Geological Survey and Dine College, in cooperation with the Navajo Division of Health, are conducting a study in the Shiprock, New Mexico, area to determine if indoor use of this coal might be contributing to some of the respiratory health problems experienced by the residents. Researchers in this study will (1) examine respiratory health data, (2) identify stove type and use, (3) analyze samples of coal that are used locally, and (4) measure and characterize air quality inside selected homes. This Fact Sheet summarizes the interim results of the study in both English and Navajo. This Fact Sheet is available in three versions: * English [800-KB PDF file ] * Navajo [computer must have Navajo language fonts installed - 304-KB PDF file] * Image of the Navajo language version [19.8-MB PDF file

  10. HVI and HVII mitochondrial DNA data in Apaches and Navajos.

    PubMed

    Budowle, Bruce; Allard, Marc W; Fisher, Constance L; Isenberg, Alice R; Monson, Keith L; Stewart, John E B; Wilson, Mark R; Miller, Kevin W P

    2002-08-01

    Most mtDNA studies on Native Americans have concentrated on hypervariable region I (HVI) sequence data. Mitochondrial DNA haplotype data from hypervariable regions I and II (HVI and HVII) have been compiled from Apaches (N=180) and Navajos (N=146). The inclusion of HVII data increases the amount of information that can be obtained from low diversity population groups. Less mtDNA variation was observed in the Apaches and Navajos than in major population groups. The majority of the mtDNA sequences were observed more than once; only 17.8% (32/180) of the Apache sequences and 25.8% of the Navajo sequences were observed once. Most of the haplotypes in Apaches and Navajos fall into the A and B haplogroups. Although a limited number of haplogroups were observed, both sample populations exhibit sufficient variation for forensic mtDNA typing. Genetic diversity was 0.930 in the Apache sample and 0.963 in the Navajo sample. The random match probability was 7.48% in the Apache sample and 4.40% in the Navajo sample. The average number of nucleotide differences between individuals in a database is 9.0 in the Navajo sample and 7.7 in the Apache sample. The data demonstrate that mtDNA sequencing can be informative in forensic cases where Native American population data are used. PMID:12185491

  11. Potential tight gas resources in a frontier province - Jurassic through Tertiary strata beneath the Brooks Range foothills, Arctic Alaska

    USGS Publications Warehouse

    Nelson, Philip H.; Bird, Kenneth J.; Houseknecht, David W.; Potter, Christopher J.; Moore, Thomas E.

    2006-01-01

    Beneath the foothills of the Brooks Range, rocks of the Lower Cretaceous-Tertiary Brookian and Jurassic-Lower Cretaceous Beaufortian megasequences have been deeply buried and exhumed, and now exhibit characteristics of 'tight gas sandstones'. The data recovered from drilling, well tests, and cores exhibit the potential for substantial gas reserves over a large area. These data include recovery of gas from drillstem tests, indications of overpressure from well tests and mud weights, low porosity and permeability in sandstones, and vitrinite reflectance values ranging from 1.0 to 2.0 percent throughout substantial depth intervals.

  12. Geology and ground water of the Red Lake area, Navajo Indian Reservation, Arizona and New Mexico

    USGS Publications Warehouse

    Akers, J.P.; McClymonds, N.E.; Harshbarger, John William

    1962-01-01

    The Red Lake area in the Navajo Indian Reservation, Arizona and New Mexico, was studied by the U.S. Geological Survey to determine if 1 mgd (mil- lion gallons per day) of water could be obtained for the requirements of a proposed sawmill. Geologic mapping and stratigraphic studies indicated three favorable areas where ground water may be developed. Test holes were drilled under contract in the areas, and pumping tests indicate that 500,000 gpd (gal- lons per day) is available from alluvium along Tohdildonih Wash near Frog Rock, 100,000 gpd is available from the Shinarump member of the Chinle forma- tion and the De Chelly sandstone near Red Lake, and 800,000 gpd is available from alluvium and cinder beds in lapiUi tuff in Buell Park, an eroded diatreme. The diatreme at Buell Park is about 2% miles in diameter. It was formed by several explosions in which lapilli tuff and cinders were erupted. These materials, together with later basaltic intrusive and extrusive rock, now fill the diatreme. The tuff and cinders are water bearing, 'and they receive re- charge from rainwater and snowmelt moving through overlying alluvium and from storage in the De Chelly sandstone which encloses the east half of the diatreme. The quality of water from all areas is suitable for domestic use. However, special treatment may be necessary to make the water suitable for pulp processing.

  13. Natural and Laboratory-Induced Compaction Bands in Aztec Sandstone

    NASA Astrophysics Data System (ADS)

    Haimson, B. C.; Lee, H.

    2002-12-01

    The Aztec sandstone used in this research is from the Valley of Fire State Park area, Nevada. This Jurassic aeolian sandstone is extremely weak (uniaxial compressive strength of 1-2 MPa); porosity averages 26%; grains are subrounded and have a bimodal size distribution (0.1 mm and 0.5 mm); its mineral composition (K. Sternlof, personal comm.) is 93% quartz, 5% k-spar, and 2% kaolinite, Fe carbonate and others; grain bonding is primarily through suturing. Sternlof et al. (EOS, November, 2001) observed substantial exposure of mainly compactive deformation bands in the Aztec sandstone. We studied an SEM image of a compaction band found in a hand sample of the Aztec sandstone. We also conducted a drilling test in a 130x130x180 mm prismatic specimen subjected to a preset far-field true triaxial stress condition (\\sigmah = 15 MPa, \\sigmav = 25 MPa, \\sigmaH = 40 MPa). Drilling of a 20 mm dia. vertical hole created a long fracture-like thin tabular breakout along the \\sigmah springline and perpendicular to \\sigmaH direction. SEM analysis of the zones ahead of the breakout tips revealed narrow bands of presumed debonded intact grains interspersed with grain fragments. We infer that the fragments were formed from multiple splitting or crushing of compacted grains in the band of high compressive stress concentration developed along the \\sigmah springline. SEM images away from the breakout tip surroundings showed no such fragments. SEM study of the natural compaction band showed a similar arrangement of mainly intact grains surrounded by grain fragments. Using the Optimas optical software package, we found the percentage of pore area within the band ahead of the breakout tips to average 17%; outside of this zone it was 23%. In the natural compaction band pore area occupied 8.5% of the band; in the host rock adjacent to the compaction band it averaged 19%. These readings strongly suggest porosity reduction due to compaction in both cases. The close resemblance between the

  14. Triassic and Jurassic-Cretaceous deposits in the Western Chukotka: geodynamic implications, provenance studies and deformation

    NASA Astrophysics Data System (ADS)

    Tuchkova, M.

    2012-04-01

    Studied region is situated in western Chukotka, in Northeast Russia. We examine the part of Chukotka microplate, the key element in the evolution of the Amerasian basin. The Triassic of Chukotka is represented by up to 5 km of deposits. Triassic terrigeneous deposits consist of three different complexes: Lower-Middle Triassic, Upper Triassic Carnian, and Norian. All the complexes are represented by rhythmic intercalation of sandstones, siltstones and mudstones. Clastic material was carried by large rivers, possessing large reservoir on neighbouring continent. Progradation of delta system in deeper regions is observed. During the Triassic, sedimentation was represented by continental slope progradation. Petrographic study of mineral composition has established the sandstones as graywackes and lithic arenites, according to Pettijohn classification (1981). Sandstones with clasts of rock fragments of lower metamorphic grade rocks dominate at the base of Triassic deposits, sandstones with fragments of higher grade metamorphic rocks dominate in the Later Triassic deposits. This different shows that the Triassic represents an unroofing sequence sours of erosional processes that produced the clastic material eroded more deeply buried rocks through time. Detrital zircons from Triassic sedimentary rocks were collected for constain its paleogeographic links to source terranes. Zircons populations from these three samples are very similar, and youngest zircon ages show peaks at 236-255 Ma. Besides, we are dating the 9 samples for K-Ar and Rb-Sr methods. Data are similar and show 200-204 Ma, and we suppose that this isotopic data indicate the age of first stage of deformation in Chukotka's basin. The Jurassic-Cretaceous of Chukotka is represented by up to 3 km of deposits. The sedimentary complexes are enriched by organic matter, and fresh clastic materials. Fragments of shales, sometimes laminated or cleaved are their indicator constituents. Sandstones are arkosic. The

  15. Taphonomy and paleoecology inferences of vertebrate ichnofossils from Guará Formation (Upper Jurassic), southern Brazil

    NASA Astrophysics Data System (ADS)

    Dentzien-Dias, Paula C.; Schultz, Cesar L.; Bertoni-Machado, Cristina

    2008-03-01

    In southern Brazil, the eolian facies of the Guará Formation (Late Jurassic) reveal footprints and trackways of vertebrates (dinosaurs), as well as burrows made by small vertebrates. All the footprints and trackways are preserved in dunes and sand sheets. The footprints made in the sand sheets are not well preserved due to intense trampling and can be distinguished only by the deformation of the sandstone laminations. In some cases it is possible to see this deformation in plan and in section. Tracks of theropods, ornithopods and middle-sized sauropods are present. Two footprints preserved in the foreset of a paleodune permitted recognition of slide structures and identification of the trackmaker, a theropod. Burrows horizontally across the foresets were found at this same paleodune. Ribbons of massive sandstone - interpreted as the partial filling of the base of the burrows - covered by little blocks of stratified sandstone - suggest the collapse of the burrow roof inward. There are no body fossils in the Guará Formation, consequently the preservation of these tracks provides unique evidence of widespread dinosaurs activity in southern Brazil near the end of the Jurassic.

  16. Upper Jurassic to Lower Cretaceous(?) synorogenic sedimentary rocks in the southern Spring Mountains, Nevada

    NASA Astrophysics Data System (ADS)

    Carr, Michael D.

    1980-08-01

    A newly recognized sequence of Upper Jurassic to Lower Cretaceous(?) terrigenous rocks in the Good-springs district, Nevada, was deposited during the emplacement of the Contact thrust plate. Two facies are recognized: (1) interbedded conglomerate and sandstone derived from Mesozoic igneous and terrigenous platform rocks and (2) interbedded carbonate and sandstone-clast conglomerate, quartz sandstone, and red shale. No igneous detritus occurs in the facies with carbonate-clast conglomerate. Carbonate clasts could only have been derived from the Paleozoic carbonate sequence, which was exposed in the area by latest Jurassic to earliest Cretaceous thrusting. The age of rocks from a volcanic unit within the synorogenic sequence was determined radiometrically to be 150 ± 10 m.y. (K-Ar on biotite). The sequence was deposited disconformably on deeply eroded rocks of the early Mesozoic platform and ultimately overridden from the west by the Contact thrust plate. Information from the sequence corroborates previously reported regional data regarding the timing and nature of the Contact-Red Springs thrust event. *Present address: U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025

  17. Assistive Technology Provision Within the Navajo Nation

    PubMed Central

    Ripat, Jacquie D.

    2014-01-01

    In this study we explored the factors that affect assistive technology (AT) provision within the Navajo Nation using a qualitative approach to inquiry. Focus groups were held in which AT users discussed their awareness of AT and their need for, use of, and satisfaction with AT devices and services. Twenty-eight individuals who used wheelchairs, orthotics or prosthetics, hearing aids, communication aids, vision aids, and other AT participated in one of seven focus groups. Seven AT providers discussed the facilitators and barriers that affect AT provision. The findings revealed six themes common to both stakeholder groups and two additional themes for AT users. The central theme for AT users centered on (not) feeling understood; the central theme for AT providers revolved around the processes, activities, and roles the providers engaged in at times for different clients. Activities to increase awareness and to promote successful AT provision and satisfaction with AT devices were proposed. PMID:25147224

  18. Teaching Initial Reading in Navajo: Report of a Conference of Educators Held at Kayenta, January 30-31, 1970. Navajo Reading Study, Progress Report No. 6.

    ERIC Educational Resources Information Center

    Murphy, Penny, Ed.

    This report includes descriptions of ongoing reading programs for Navajo students in Rough Rock, Rock Point, and Navajo Community College, presented by teacher-participants in the conference on reading held in Kayenta, Arizona, January 30-31, 1970. Also included are reports from the Navajo Reading Study staff and a discussion of the problems of…

  19. Uranium mining and lung cancer in Navajo men

    SciTech Connect

    Samet, J.M.; Kutvirt, D.M.; Waxweiler, R.J.; Key, C.R.

    1984-06-07

    We performed a population-based case-control study to examine the association between uranium mining and lung cancer in Navajo men, a predominantly nonsmoking population. The 32 cases included all those occurring among Navajo men between 1969 and 1982, as ascertained by the New Mexico Tumor Registry. For each case in a Navajo man, two controls with nonrespiratory cancer were selected. Of the 32 Navajo patients, 72 per cent had been employed as uranium miners, whereas no controls had documented experience in this industry. The lower 95 per cent confidence limit for the relative risk of lung cancer associated with uranium mining was 14.4. Information on cigarette smoking was available for 21 of the 23 affected uranium miners; eight were nonsmokers and median consumption by the remainder was one to three cigarettes daily. These results demonstrate that in a rural nonsmoking population most of the lung cancer may be attributable to one hazardous occupation.

  20. Navajo coal and air quality in Shiprock, New Mexico

    USGS Publications Warehouse

    Bunnell, Joseph E.; Garcia, Linda V.

    2006-01-01

    Among the Navajo people, high levels of respiratory disease, such as asthma, exist in a population with low rates of cigarette smoking. Air quality outdoors and indoors affects respiratory health. Many Navajo Nation residents burn locally mined coal in their homes for heat, as coal is the most economical energy source. The U.S. Geological Survey and Dine College, in cooperation with the Navajo Division of Health, are conducting a study in the Shiprock, New Mexico, area to determine if indoor use of this coal might be contributing to some of the respiratory health problems experienced by the residents. Researchers in this study will (1) examine respiratory health data, (2) identify stove type and use, (3) analyze samples of coal that are used locally, and (4) measure and characterize air quality inside selected homes. This Fact Sheet summarizes the interim results of the study in both English and Navajo.

  1. TECHNICAL SUPPORT TO NAVAJO NATION ON URANIUM MINING TENORM WASTES.

    EPA Science Inventory

    Assistance is being provided to the Navajo Nation to establish its own radiation protection standards, radiation action levels, identification of safe drinking water sources, safe disposal of radioactive TENORM wastes from abandoned uranium mines, and to locate and decontaminate ...

  2. Depth and thickness of selected units in Upper Permian, Upper Jurassic, and Lower Cretaceous rocks in southwestern Kansas

    USGS Publications Warehouse

    Kume, Jack; Spinazola, Joseph M.

    1984-01-01

    As ground-water reserves decline in the Ogallala aquifer in an area of about 17,400 square miles in 26 counties of southwestern Kansas, sandstone aquifers in underlying Upper Jurassic and Lower and Upper Cretaceous rocks may be developed to supplement or replace the Ogallala as a source of water for some uses. Maps show that depths from land surface to Upper Permian rocks range from 0 at the outcrop to over 2,100 feet, depths to Upper Jurassic rocks ran from 0 at the outcrop to about 2,000 feet, depths to the Cheyenne Sandstone range from about 150 to about 1 ,950 feet, and depths to the Dakota Formation range from 0 at the outcrop to about 1,650 feet. Additional maps show that the thickness of Upper Jurassic rocks, where present, ranges from less than 50 feet to about 250 feet, the thickness of the Cheyenne Sandstone, where present, ranges from about 20 feet to about 250 feet, and the thickness of the Dakota Formation, where present, ranges from about 60 feet to about 460 feet. (USGS)

  3. Late Jurassic weather forecast, Four Corners area: Dry, hot, and partly sunny

    SciTech Connect

    Turner-Peterson, C.E.; Fishman, N.S. )

    1989-09-01

    Interfingering between members of the Upper Jurassic Morrison Formation and inferences based on their various environments of deposition permit interpretation of a persistent paleoclimate during the Late Jurassic in the Colorado Plateau region. Paleoclimate interpretation is based on evaporites in the Tidwell member, at the base of the Morrison; eolian deposits in the Recapture and Bluff Sandstone members; and saline, alkaline-lake deposits (which indicate high evaporation rates) in the Brushy Basin member at the top of the Morrison. Interfingering of these members with all other members of the Morrison Formation implies that a semiarid to arid climate was likely throughout Morrison time. The semiarid to arid interpretation is consistent with the global climatic zone inferred from the paleogeographic/paleotectonic setting. The Four Corners area during the Late Jurassic was in the middle latitudes of the Northern Hemisphere and thus was affected by prevailing westerly winds. A magmatic arc located several hundred kilometers to the west of the Morrison depositional basin may have caused a broad rain-shadow effect, which contributed to a dry continental climate downwind. A typical Late Jurassic day in the Four Corners area is predicted to have been hot and dry, although seasonally heavy rains probably fed intermittent streams that transported sediments into the region. Explosive eruptions of silicic volcanic ash may have darkened the skies episodically, and thus partly sunny would have been a conservative forecast.

  4. Navajo: A Century of Progress, 1868-1968.

    ERIC Educational Resources Information Center

    Link, Martin A., Ed.

    The year 1968 marks the 100th anniversary of the signing of the Treaty of Peace between the Navajo tribe and the U.S. Government. The treaty, signed by 29 Navajo headmen and 10 officers of the U.S. Army on June 1, 1968, brought to an end a tragic period of suffering, hardship, deprivation, and exile at the Bosque Redondo, New Mexico. During the…

  5. Composition, provenance and source weathering of Mesozoic sandstones from Western-Central Mediterranean Alpine Chains

    NASA Astrophysics Data System (ADS)

    Perri, F.

    2014-03-01

    Forty-two Mesozoic sandstone samples from three different sedimentary successions of the Internal Domains along the Western-Central Mediterranean Alpine Chains (Betic Cordillera, Rif Chain and Calabria-Peloritani Arc) were chemically analyzed to characterize their composition and the degree of weathering in the source area(s). The Rif Chain sandstones have SiO2 contents higher than those of the Calabria-Peloritani Arc and Betic Cordillera sandstones, whereas Al2O3 contents are higher in the Calabria-Peloritani Arc sandstones rather than in the Rif Chain and Betic Cordillera sandstones. The indices of compositional variability (ICV) of the studied samples are generally less than 1, suggesting that the samples are compositionally mature and were likely dominated by recycling. Recycling processes are also shown by the Al-Zr-Ti diagram indicating zircon addition and, thus, recycling processes. The Chemical Index of Alteration (CIA) values are quite homogeneous for the Calabria-Peloritani Arc (mean = 76) and Betic Cordillera sandstones (mean = 55), whereas the Rif Chain sandstones are characterized by CIA values ranging from 54 to 76. The CIW and PIA values are high for all the studied sandstones indicating intense weathering at the source areas. The different values of weathering rates among the studied sandstones may be related to variations of paleoclimatic conditions during the Mesozoic, that further favored recycling processes. Thus, these differences among the studied samples, may be related to an increase in continental palaeoweathering conditions and sediment recycling effects from the Middle Triassic to the earliest Jurassic due to rising humidity. In addition, regional tectonic movements promoted structural changes that allowed sedimentary recycling and subsidence, which in turn caused diagenetic K-metasomatism. These processes could significantly affect the CIW and PIA weathering indices, which likely monitor a cumulative effect, including several cycles of

  6. Protecting the Navajo People through tribal regulation of research.

    PubMed

    Brugge, Doug; Missaghian, Mariam

    2006-07-01

    This essay explores the process and issues related to community collaborative research that involves Native Americans generally, and specifically examines the Navajo Nation's efforts to regulate research within its jurisdiction. Researchers need to account for both the experience of Native Americans and their own preconceptions about Native Americans when conducting research about Native Americans. The Navajo Nation institutionalized an approach to protecting members of the nation when it took over Institutional Review Board (IRB) responsibilities from the US Indian Health Service (IHS) in 1996. While written regulations for the Navajo Nation IRB are not dissimilar, and in some ways are less detailed than those of the IHS IRB, in practice the Navajo Nation allows less flexibility. Primary examples of this include not allowing expedited review and requiring prepublication review of all manuscripts. Because of its broad mandate, the Navajo Nation IRB may also require review of some projects that would not normally be subject to IRB approval, including investigative journalism and secondary research about Navajo People that does not involve direct data collection from human subjects. PMID:16909151

  7. Distribution, chemistry, isotopic composition and origin of diagenetic carbonates: Magnus Sandstone, North Sea

    SciTech Connect

    Macaulay, C.I.; Haszeldine, R.S. ); Fallick, A.E. )

    1993-01-01

    Diagenetic ferroan carbonates grew in the Upper Jurassic reservoir sandstones of the Magnus oilfield in porewaters which differed in composition across the field. These porewaters remained compositionally different and stratified for at least 35 M.y. Variations in carbonate chemistry across the field are attributable to these porewater variations, which resulted from displacement of marine depositional water from the crest of the field by meteoric water during late Cimmerian subaerial exposure. Original depositional facies and detrital mineralogy strongly influenced diagenetic carbonate distribution. The objective of this paper is twofold: (1) to describe the occurrence of burial diagenetic magnesian siderite and ankerite from the Magnus Sandstone, and (2) to show that variations in the elemental and isotopic geochemistry of siderite and ankerite relate to long-lived variations in the composition of the porewaters in the sandstone during diagenesis.

  8. Diagenesis of Upper Jurassic Norphlet Formation, Mobile and Baldwin Counties and offshore Alabama

    SciTech Connect

    Vaughan, R.L. Jr.; Benson, D.J.

    1988-09-01

    The Upper Jurassic Norphlet Formation is an important deep gas reservoir in Mobile and Baldwin Counties and offshore Alabama. The producing reservoir consists of a well-sorted fine-grained subarkose to arkose. Sedimentological studies indicate this unit was deposited on a broad desert plain in environments ranging from eolian dune and interdune to wadi and beach-shoreface. Diagenetic minerals comprise from 5 to 20% of the bulk volume of the sandstone. Porosity ranges from less than 3% to more than 25% and averages around 10%. Most of the porosity consists of hybrid solution-enlarged intergranular and intragranular pores resulting from the dissolution of cements, framework grains, and grain replacements.

  9. STEM Summer Academy on the Navajo Reservation

    NASA Astrophysics Data System (ADS)

    Alexander, C. J.

    2012-12-01

    The US Rosetta Project is the NASA contribution to the International Rosetta Mission, an ESA cornerstone mission to comet Churyumov-Gerasimenko. While the project's outreach efforts span multi-media, and a variety of age and ethnic groups, a special emphasis has been made to find a way to provide meaningful outreach to the reservation communities. Because language preservation is an issue of urgent concern to the reservation communities, and because Rosetta, uniquely among NASA missions, has been named after the notion that keys to missing understanding of elements of the ancient past were found in the language on the original Rosetta stone, the US Rosetta Project has embarked upon outreach with a focus on STEM vocabulary in ancient US languages of the Navajo, Hopi, Ojibwe, and other tribal communities as the project expands. NASA image and science are used and described in the native language, alongside lay English and scientific English curriculum elements. Additionally, science (geology/chemistry/botany/physics) elements drawn from the reservation environment, including geomorphology, geochemistry, soil physics, are included and discussed in the native language as much as possible — with their analogs in other planetary environments (such as Mars). In this paper we will report on the most recent Summer Science Academy [2012], a four week summer course for middle school children, created in collaboration with teachers and administrators in the Chinle Unified School District. The concept of the Academy was initiated in 2011, and the first Academy was conducted shortly thereafter, in June 2011 with 14 children, 3 instructors, and a NASA teacher workshop. The community requested three topics: geology, astronomy, and botany. The 2012 Academy built on the curriculum already developed with more robust field trips, addressed to specific science topics, additional quantitative measurements and activities, with more written material for the cultural components from

  10. 78 FR 32273 - Renewal of Agency Information Collection for Navajo Partitioned Lands Grazing Permits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... for Navajo Partitioned Lands Grazing Permits authorized by OMB Control Number 1076-0162. This.... Data OMB Control Number: 1076-0162. Title: Navajo Partitioned Lands Grazing Permits, 25 CFR 161....

  11. A Jurassic mammal from South America.

    PubMed

    Rauhut, Oliver W M; Martin, Thomas; Ortiz-Jaureguizar, Edgardo; Puerta, Pablo

    2002-03-14

    The Jurassic period is an important stage in early mammalian evolution, as it saw the first diversification of this group, leading to the stem lineages of monotremes and modern therian mammals. However, the fossil record of Jurassic mammals is extremely poor, particularly in the southern continents. Jurassic mammals from Gondwanaland are so far only known from Tanzania and Madagascar, and from trackway evidence from Argentina. Here we report a Jurassic mammal represented by a dentary, which is the first, to our knowledge, from South America. The tiny fossil from the Middle to Late Jurassic of Patagonia is a representative of the recently termed Australosphenida, a group of mammals from Gondwanaland that evolved tribosphenic molars convergently to the Northern Hemisphere Tribosphenida, and probably gave rise to the monotremes. Together with other mammalian evidence from the Southern Hemisphere, the discovery of this new mammal indicates that the Australosphenida had diversified and were widespread in Gondwanaland well before the end of the Jurassic, and that mammalian faunas from the Southern Hemisphere already showed a marked distinction from their northern counterparts by the Middle to Late Jurassic. PMID:11894091

  12. Log interpretation of shaly sandstones

    SciTech Connect

    Baker, J.F.

    1988-01-01

    The determination of water saturation from electrical resistivity measurements to evaluate the potential of reservoirs is a fundamental tool of the oil industry. Shaly sandstones are difficult to evaluate because clays are conductive and they lower the resistivity of the rock. A review of shaly-sandstone research concerning ''volume-of-shale'' equations reveals three theoretical categories: (1) laminated clay equations, (2) dispersed clay equations, and (3) equations that assume that the effect of the clays on the conductivity measurement is directly related to water saturation. A new model for predicting the relative amounts of laminated and dispersed shales and accounting for their effects according to their abundance can be used for any sandstone, clean or shaly. Equations representing each of the three theoretical categories and the new equation were tested on cored Wilcox sandstones from two wells. Cores were analyzed to determine the volume and distribution of clays and to correlate porosity with the well logs.

  13. Tuning In to Navajo: The Role of Radio in Native Language Maintenance.

    ERIC Educational Resources Information Center

    Peterson, Leighton C.

    Since 1986, KTNN Radio (tribally owned) has broadcast Navajo-language programming to the entire Navajo Nation. Its large broadcast range and position as the "Voice of the Navajo Nation" gives KTNN the "symbolic" power to affect linguistic change, as well as the unenviable position of being held to a high language standard although no such…

  14. Peer Group Evaluation of Narrative Competence: A Navajo Example. Working Papers in Sociolinguistics, No. 47.

    ERIC Educational Resources Information Center

    Brady, Margaret

    The narrative performances of Navajo children were examined to determine the ways in which the skills of competently structuring a narrative are informally learned within the peer group. Ten- and eleven-year-old Navajo children, living near Window Rock, Arizona, were evaluated in telling stories about the most traditional figures of Navajo belief,…

  15. The Feasibility of Test Translation between Unrelated Languages: English to Navajo

    ERIC Educational Resources Information Center

    Rosenbluth, Annabelle R.

    1976-01-01

    The Boehm Test of Basic Concepts was translated into Navajo to investigate whether an English test can be translated into Navajo in a form suitable for assessing the language development of K-2 level Navajos. Differences were in: syntactic difficulty, organization of experience into concepts, accidental similarity of words, ranges of meaning. (SCC)

  16. Navajo Materials For Classroom Use: K-12 Curriculum Directory (Preliminary Edition).

    ERIC Educational Resources Information Center

    Johnson, Gene, Comp.; And Others

    Compiled as part of Title IV-B Materials Development Project at Rough Rock Demonstration School, the bibliography attempts to address: (1) what Navajo-based materials already exist and are available; (2) where Navajo curriculum development is currently taking place; and (3) what needs exist at the present stage of Navajo curriculum development.…

  17. A Little History of North American Indians: The Navajos. New Edition.

    ERIC Educational Resources Information Center

    Lipps, Oscar H.

    This reprint of a 1909 volume portrays the life and history of the Navajo people, based on the personal experiences of an unusually enlightened white observer. The first three chapters cover the Navajo's early history, discovery by Spanish explorers, evidence of a prehistoric and possibly ancestral race, and the beauties of the Navajo's rugged…

  18. The Trading Post System on the Navajo Reservation. Staff Report to the Federal Trade Commission.

    ERIC Educational Resources Information Center

    Federal Trade Commission, Los Angeles, CA.

    Since the late 19th century, trading posts have been a prominant feature in Navajo economic life. Today, due to geographic isolation and an absence of economic alternatives, many Navajos are still dependent upon trading posts. This report of a Federal Trade Commission (FTC) investigation details the system on the Navajo Reservation, including the…

  19. Crosscultural Contacts: Changes in the Diet and Nutrition of the Navajo Indians.

    ERIC Educational Resources Information Center

    Kopp, Judy

    1986-01-01

    Describes changes in Navajo food sources in pre-colonial times, through nineteenth-century war with American soldiers and to contemporary times. Discusses nutritional value of Navajo diets, suggesting food changes following Indian contact with economically developed White culture was harmful to Navajo health. Suggests areas for further study. (TES)

  20. The Image of the Scientist through the Eyes of Navajo Children.

    ERIC Educational Resources Information Center

    Monhardt, Rebecca M.

    2003-01-01

    A study of Navajo children's attitude towards scientists asked 94 southern Utah Navajo students in grades 4-6 to draw a scientist. Although many students appeared to have no conception of what a scientist is, the drawings provided unique insights into Navajo students' perceptions, racial and gender sterotypes, and world views. Implications for…

  1. We Could Make a Book: The Textual Tradition of Navajo Language Literacy in 1940-1990.

    ERIC Educational Resources Information Center

    Lockard, Louise

    1998-01-01

    The textual tradition of Navajo language literacy is illustrated with the story of the production of the first Navajo language readers by Ann Nolan Clark, an effort based in Navajo classrooms and communities in the 1930s. Origins of the project, influence of linguists on its evolution, classroom implications of having the readers, and publications…

  2. Social Studies Concept Attainment of Anglo and Navajo Indian Sixth-Grade Students

    ERIC Educational Resources Information Center

    Ritt, Sharon Isaacson

    1978-01-01

    Compares understanding of social studies concepts among 6th grade Navajo and Anglo students in four Arizona communities. Findings indicated that Anglo students' scores exceeded those of Navajo students for all concepts and tasks. Offers recommendations for increasing Navajo students' comprehension of social studies. (DB)

  3. 30 CFR 756.15 - Required amendments to the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS § 756.15 Required amendments to the Navajo Nation's abandoned mine land plan. Pursuant to 30 CFR 884.15, the Navajo Nation is required to submit to OSM by the date specified either a proposed... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Required amendments to the Navajo...

  4. 78 FR 23277 - Navajo Nation; Amendment No. 1 to Notice of a Major Disaster Declaration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... SECURITY Federal Emergency Management Agency Navajo Nation; Amendment No. 1 to Notice of a Major Disaster... notice of a major disaster declaration for the Navajo Nation (FEMA-4104-DR), dated March 5, 2013, and... for the Navajo Nation is hereby amended to include the following area among those areas determined...

  5. 30 CFR 756.15 - Required amendments to the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS § 756.15 Required amendments to the Navajo Nation's abandoned mine land plan. Pursuant to 30 CFR 884.15, the Navajo Nation is required to submit to OSM by the date specified either a proposed... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Required amendments to the Navajo...

  6. 25 CFR 700.843 - Permitting procedures for Navajo Nation Lands.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Permitting procedures for Navajo Nation Lands. 700.843... RELOCATION PROCEDURES New Lands Grazing § 700.843 Permitting procedures for Navajo Nation Lands. (a) Pursuant to the Act and this subpart, the written consent of the Navajo Nation is required. Written...

  7. 30 CFR 756.14 - Approval of amendments to the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Approval of amendments to the Navajo Nation's... PROGRAMS § 756.14 Approval of amendments to the Navajo Nation's abandoned mine land plan. (a) Revisions to the following provisions of the Navajo Nation AMLR plan, as submitted to OSM on April 7 and 22,...

  8. 25 CFR 700.843 - Permitting procedures for Navajo Nation Lands.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Permitting procedures for Navajo Nation Lands. 700.843... RELOCATION PROCEDURES New Lands Grazing § 700.843 Permitting procedures for Navajo Nation Lands. (a) Pursuant to the Act and this subpart, the written consent of the Navajo Nation is required. Written...

  9. 30 CFR 756.14 - Approval of amendments to the Navajo Nation's abandoned mine land plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Approval of amendments to the Navajo Nation's... PROGRAMS § 756.14 Approval of amendments to the Navajo Nation's abandoned mine land plan. (a) Revisions to the following provisions of the Navajo Nation AMLR plan, as submitted to OSM on April 7 and 22,...

  10. Stephannie and the Coyote (Stefanii doo Ma'ii) in Navajo and English.

    ERIC Educational Resources Information Center

    Crowder, Jack L.

    Intended as a supplementary text or a library book for Navajo children, this book is written both in English and Navajo. Color pictures illustrate each passage in the text. The pictures graphically depict the living conditions of the Navajo people. (TL)

  11. Local Navajo Norms for the Wechsler Intelligence Scale for Children: Third Edition.

    ERIC Educational Resources Information Center

    Tempest, Phyllis

    1998-01-01

    A project developed Navajo norms for the Wechsler Intelligence Scale for Children, Third Edition (WISC-III). Urban Navajo students and those who were proficient in English had higher WISC-III verbal scores than rural Navajo students and those who were functional in English. English-language proficiency did not affect scores on nonverbal…

  12. Presence of the dinosaur Scelidosaurus indicates Jurassic age for the Kayenta Formation (Glen Canyon Group, northern Arizona)

    NASA Astrophysics Data System (ADS)

    Padian, Kevin

    1989-05-01

    The Glen Canyon Group (Moenave, Wingate, Kayenta and Navajo Formations) of northern Arizona represents an extensive outcrop of early Mesozoic age terrestrial sediments. The age of these formations has long been disputed because independent stratigraphic data from marine tie-ins, paleobotanical and palynological evidence, and radiometric calibrations have been scanty or absent. The fauna of the Kayenta Formation in particular has been problematic because it has appeared to contain both typical Late Triassic and Early Jurassic taxa Here I report that the principal evidence for Late Triassic taxa, dermal scutes previously assigned to an aetosaur, in fact belongs to the thyreophoran ornithischian dinosaur Scelidosaurus, previously known only as a washed-in form found in marine sediments in the Early Jurassic of England. The presence of this dinosaur represents the first vertebrate biostratigraphic tie-in of the Glen Canyon Group horizons with reliably dated marine deposits in Europe. Together with revised systematic assessments of other vertebrates and independent evidence from fossil pollen, it supports an Early Jurassic age for the Kayenta Formation and most or all of the Glen Canyon Group.

  13. Navajo-Hopi Land Commission Renewable Energy Development Project (NREP)

    SciTech Connect

    Thomas Benally, Deputy Director,

    2012-05-15

    The Navajo Hopi Land Commission Office (NHLCO), a Navajo Nation executive branch agency has conducted activities to determine capacity-building, institution-building, outreach and management activities to initiate the development of large-scale renewable energy - 100 megawatt (MW) or larger - generating projects on land in Northwestern New Mexico in the first year of a multi-year program. The Navajo Hopi Land Commission Renewable Energy Development Project (NREP) is a one year program that will develop and market a strategic business plan; form multi-agency and public-private project partnerships; compile site-specific solar, wind and infrastructure data; and develop and use project communication and marketing tools to support outreach efforts targeting the public, vendors, investors and government audiences.

  14. Petrography and diagenesis of Eagle Mills sandstones, subsurface - Northeast Texas and southwest Arkansas

    SciTech Connect

    Dawson, W.C.; Callender, C.A. )

    1991-03-01

    The Eagle Mills Formation (Triassic-Jurassic) has been penetrated by several deep wells (12,000 to 18,000 ft) in northeast Texas and southwest Arkansas. It consists of green, red, and pink conglomeratic lithic arenites and fine- to coarse-grained feldspathic arenites, interbedded with red and greenish gray shales and siltstones. Lithic arenites contain basalt, chert, quartzite, and dolomite rock fragments; plagioclase is the predominant feldspar. All Eagle Mills sandstones have low textural and mineralogic maturities. Eagle Mills red beds and associated intrusive igneous rocks (diabase and basalt dikes and sills) represent the fillings of grabens or rift basins that actively subsided during deposition (in alluvial, fluvial-deltaic, and lacustrine paleoenvironments). Eagle Mills lithic and feldspathic sandstones have undergone a complex diagenetic history, including chlorite cementation (pore linings and pore fillings), compaction, quartz and feldspar overgrowths, dolomite cementation, chloritization and albitization of detrital feldspars, local dissolution of framework grains (igneous lithics and feldspars), precipitation of kaolinite, late Fe-calcite cementation, and saddle dolomite formation. Cement mineralogies are strongly correlative with lithofacies. Lithic sandstones contain the highest frequency of chlorite cements, whereas feldspathic sandstones are preferentially cemented with carbonates and anhydrite; quartz and feldspar overgrowths are ubiquitous. The suite of authigenic minerals in Eagle Mills sandstones records progressive burial into a deep, high-temperature (120-150C), semiclosed, diagenetic regime.

  15. Preliminary bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle, Navajo and Apache Counties, northern Arizona

    USGS Publications Warehouse

    Amoroso, Lee; Priest, Susan S.; Hiza-Redsteer, Margaret

    2014-01-01

    The bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle was completed in a cooperative effort of the U.S. Geological Survey (USGS) and the Navajo Nation to provide regional geologic information for management and planning officials. This report provides baseline geologic information that will be useful in future studies of groundwater and surface water resources, geologic hazards, and the distribution of soils and plants. The west half of the Sanders quadrangle encompasses approximately 2,509 km2 (980 mi2) within Navajo and Apache Counties of northern Arizona and is bounded by lat 35°30' to 35° N., long 109°30' to 110° W. The majority of the land within the map area lies within the Navajo Nation. South of the Navajo Nation, private and State lands form a checkerboard pattern east and west of Petrified Forest National Park. In the west half of the Sanders quadrangle, Mesozoic bedrock is nearly flat lying except near folds. A shallow Cenozoic erosional basin that developed about 20 Ma in the western part of the map area cut across late Paleozoic and Mesozoic rocks that were subsequently filled with flat-lying Miocene and Pliocene mudstone and argillaceous sandstone and fluvial sediments of the Bidahochi Formation and associated volcanic rocks of the Hopi Buttes volcanic field. The Bidahochi rocks are capped by Pliocene(?) and Pleistocene fluvial sediments and Quaternary eolian and alluvial deposits. Erosion along northeast-southwest-oriented drainages have exposed elongated ridges of Bidahochi Formation and basin-fill deposits that are exposed through shallow eolian cover of similarly oriented longitudinal dunes. Stokes (1964) concluded that the accumulation of longitudinal sand bodies and the development of confined parallel drainages are simultaneous processes resulting in parallel sets of drainages and ridges oriented along the prevailing southwest wind direction on the southern Colorado Plateau.

  16. World petroleum systems with Jurassic source rocks

    SciTech Connect

    Klemme, H.D. )

    1993-11-08

    Fourteen petroleum systems with Upper Jurassic source rocks contain one quarter of the world's discovered oil and gas. Eleven other systems with Lower and Middle Jurassic source rocks presently have a minor but significant amount of discovered oil and gas. The purpose of this article is to review the systems geologically, describe their location in space and time on a continental scale, estimate their relative petroleum system recovery efficiencies, and outline the effect their essential elements and processes have on their petroleum plumbing.

  17. Jurassic-Neocomian biostratigraphy, North Slope, Alaska

    SciTech Connect

    Mickey, M.B.; Haga, H.

    1985-04-01

    The foraminiferal and palynological biostratigraphy of subsurface Jurassic and Neocomian (Early Cretaceous) age strata from the North Slope were investigated to better define biostratigraphic zone boundaries and to help clarify the correlation of the stratigraphic units in the National Petroleum Reserve in Alaska (NPRA). Through use of micropaleontologic data, eight principal biostratigraphic units have been identified. The Neocomian and Jurassic strata have each been subdivided into four main units.

  18. Diagenesis of deeply buried Eagle Mills sandstones. Implications for paleo-fluid migration and porosity development

    SciTech Connect

    Dawson, W.C.

    1995-10-01

    Eagle Mills strata (Triassic-Jurassic) unconformably overlie the Paleozoic basement complex and thus, form the basal sedimentary unit within the Gulf Coast basin. Jurassic-aged basaltic dikes and sills have intruded Eagle Mills strata. These sedimentary and igneous rocks are the earliest record of Gulf of Mexico rifting. Deeply buried (15,000 to 18,000 ft.) Eagle Mills sandstone have subarkosic and sublithic modal compositions. These sandstones exhibit evidence of a complex and prolonged diagnetic history, including: early chlorite cementation; early quartz and feldspar overgrowths; early calcite and dolomite cementation; dissolution of framework grains and early carbonate cements; kaolinite precipitation; late ferroan carbonate cementation; albitization; late chlorite and anhydrite replacement; saddle dolomite cementation; and pyritization. Pyrobitumens coat early chlorite rim cements indicating that most diagenesis post-dated hydrocarbon migration. Secondary porosity development coincided with a later burial dissolution event. The Eagle Mills paragenetic sequence records progressive burial into a high-temperature diagenetic regime where thermochemical sulfate reduction was the dominant process. Marked shifts in paleo-water chemistry are recorded by the Eagle Mills diagenetic sequence. Pervasive dissolution of detrital feldspars in some Eagle Mills sandstones provides unequivocal petrographic evidence for deep-seated sourcing of diagenetic fluids, which migrated along faults, and contributed to the diagenesis of overlying Mesozoic strata. These petrographic analyses support interpretations of geochemical/fluid-flux data for the Mesozoic Gulf Coast basin.

  19. The Scalpel and the Silver Bear. The First Navajo Woman Surgeon Combines Western Medicine and Traditional Healing.

    ERIC Educational Resources Information Center

    Alvord, Lori Arviso; Van Pelt, Elizabeth Cohen

    In this autobiography, Lori Arviso Alvord describes her journey to become the first Navajo woman surgeon and her realization of the benefits of Navajo philosophy to the healing process. Raised on the Navajo reservation by a White mother and a Navajo father and grandmother, Alvord learned to walk in two worlds. Encouraged to get an education, she…

  20. Sea level reconstructions and non-marine sedimentation at the Triassic-Jurassic boundary: southwestern margin of the Neotethys in the Salt Range, Pakistan

    NASA Astrophysics Data System (ADS)

    Iqbal, Shahid; Wagreich, Michael

    2016-04-01

    The environmental changes during the Triassic-Jurassic boundary interval and the associated mass extinction event are still strongly debated. Sea-level reconstruction records during this interval reveal an end-Triassic global regression event. Erosion and karstification at the top of Triassic sediments, and Lower Jurassic fluvial channels with reworked Triassic clasts indicate widespread regression in the European basins. Laterite at the top of the Triassic, and quartzose conglomerates/sandstones at the base of the Jurassic indicate a fluvial/terrestrial onset in Iran and Afghanistan. Abrupt emergence, erosion and facies dislocation, from the Triassic dolomites (Kingriali Formation) to Lower Jurassic fluvial/continental quartzose conglomerates/pebbly sandstones (Datta Formation) occur in the Tethyan Salt Range of Pakistan. Sedimentological analyses indicate marine regression and emergence under tropical-subtropical conditions (Greenhouse conditions) and negates the possibility of glacial influence in this region. Field evidences indicate the presence of an undulatory surface at the base of the Jurassic and a high (Sargodha High) is present south of the Salt Range Thrust, the southern boundary of the basin. Furthermore, geophysical data (mostly seismic sections) in different parts of the basin display normal faults in the basement. These features are interpreted as horst and graben structures at the Triassic-Jurassic boundary in the Kohat-Potwar Plateau. The Lower Jurassic Datta Formation appears to have been deposited in an overall graben fill settings. Similar normal faults and graben fill geometries are observed on seismic sections in Tanzania, Mozambique, Madagascar and other regions of the southeastern margin of the African Plate and are related to the Karoo rift system. To summarize, the basement normal faults and the graben fill features at the Triassic-Jurassic boundary in the Kohat-Potwar Plateau can be correlated to similar features common in the Karoo

  1. Jurassic sequence stratigraphy of the eastern Gulf Coastal Plain: Applications to hydrocarbon exploration

    SciTech Connect

    Tew, B.H.; Mancini, E.A.; Mink, R.M. )

    1991-03-01

    Based on regional stratigraphic and sedimentologic data, three unconformity-bounded depositional sequences associated with cycles of relative sea-level change and coastal onlap are recognized for Jurassic strata in the eastern Gulf Coastal Plain area. These sequences are designated, in ascending order, the LZAGC (Lower Zuni A Gulf Coast)-3.1, the LZAGC-4.1, and the LZAGC-4.2 sequences and include Callovian through Kimmeridgian Stage strata. An understanding of the relationship of Jurassic reservoirs to sequence stratigraphy can serve as an aid to hydrocarbon exploration in the eastern gulf area. The most extensive and productive Jurassic hydrocarbon reservoirs in the study area occur within the progradational, regressive highstand deposits of the LZAGC-3.1 and LZAGC-4.1 depositional sequences. For example, the majority of Norphlet sandstone reservoirs in the onshore and offshore Alabama area are interpreted to have accumulated in eolian dune, interdune, and wadi (fluvial) depositional environments, which occurred in association with the highstand regressive system of the LZAGC-3.1 sequence. The most important Smackover reservoirs generally consist of partially to completely dolomitized ooid and peloid packstones and grainstones in the upper portion of the unit. These reservoirs occur in subtidal to supratidal, shoaling-upward carbonate mudstone to grainstone cycles in the highstand regressive system of the LZAGC-4.1 sequence. In addition, minor reservoirs that are discontinuous and not well developed are associated with the shelf margin and transgressive systems of the LZAGC-4.1.

  2. Geographic information system (G.I.S.) research project at Navajo Community College - Shiprock Campus

    SciTech Connect

    Yazzie, R.; Peter, C.; Aaspas, B.; Isely, D.; Grey, R.

    1995-12-31

    The Navajo and Hopi GIS Project was established to assess the feasibility and impact of implementing GIS techology at Tribal institutions. Los Alamos and Lawrence Livermore National Laboratories funded the Navajo and Hopi Geographic Information System (G.I.S.) Project and assigned a mentor from LANL to help guide the project for three summer months of 1995. The six organizations involved were: LANL, LLNL, Navajo Community College, Navajo Nation Land Office, Northern Arizona University and San Juan College. The Navajo Land Office provided the system software, hardware and training. Northern Arizona University selected two students to work at Hopi Water Resource Department. Navajo Community College provided two students and two faculty members. San Juan College provided one student to work with the N.C.C. group. This made up two project teams which led to two project sites. The project sites are the Water Resource Department on the Hopi reservation and Navajo Community College in Shiprock, New Mexico.

  3. Lower Cretaceous and Upper Jurassic oil reservoirs of the updip basement structure play: Southwest Alabama

    SciTech Connect

    Mink, R.M.; Mancini, E.A.

    1995-10-01

    Exploration for Lower Cretaceous and Upper Jurassic reservoirs associated with updip basement structures currently is the most active exploratory oil play in Alabama. High initial flow rates, on the order of hundreds to thousands of barrels of oil per day, are commonly encountered at depths between 8,200 and 14,500 feet. Fifty-one fields have been established and 25 million barrels of oil have been produced from these fields developed in Lower Cretaceous Hosston and Upper Jurassic Haynesville, Smackover, and Norphlet reservoirs. Production from Smackover carbonates began at Toxey field in 1967 and from Haynesville sandstones at Frisco City field in 1986. As of September 1994, Smackover wells averaged 88 barrels of oil per day and Haynesville wells averaged 284 barrels of oil per day. In 1994, production was established in the Norphlet at North Excel field and in the Hosston at Pleasant Home field. Reservoirs in the updip basement structure play cluster in three distinct areas; (1) a western area on the Choctaw ridge complex, (2) a central area on the Conecuh ridge complex, and (3) an eastern area in the Conecuh embayment. Reservoir lithologies include Smackover limestones and dolostones and Hosston, Haynesville, Smackover, and Norphlet sandstones. Hydrocarbon traps are structural or combination traps where reservoirs occur on the flanks or over the crests of basement palohighs. An understanding of the complex reservoir properties and trap relationships is the key to successful discovery and development of Lower Cretaceous and Upper Jurassic oil reservoirs of the updip basement structure play of southwest Alabama.

  4. Eruptive conditions and depositional processes of Narbona Pass Maar volcano, Navajo volcanic field, Navajo Nation, New Mexico (USA)

    NASA Astrophysics Data System (ADS)

    Brand, Brittany D.; Clarke, Amanda B.; Semken, Steven

    2009-01-01

    Phreatomagmatic deposits at Narbona Pass, a mid-Tertiary maar in the Navajo volcanic field (NVF), New Mexico (USA), were characterized in order to reconstruct the evolution and dynamic conditions of the eruption. Our findings shed light on the temporal evolution of the eruption, dominant depositional mechanisms, influence of liquid water on deposit characteristics, geometry and evolution of the vent, efficiency of fragmentation, and the relative importance of magmatic and external volatiles. The basal deposits form a thick (5-20 m), massive lapilli tuff to tuff-breccia deposit. This is overlain by alternating bedded sequences of symmetrical to antidune cross-stratified tuff and lapilli tuff; and diffusely-stratified, clast-supported, reversely-graded lapilli tuffs that pinch and swell laterally. This sequence is interpreted to reflect an initial vent-clearing phase that produced concentrated pyroclastic density currents, followed by a pulsating eruption that produced multiple density currents with varying particle concentrations and flow conditions to yield the well-stratified deposits. Only minor localized soft-sediment deformation was observed, no accretionary lapilli were found, and grain accretion occurs on the lee side of dunes. This suggests that little to no liquid water existed in the density currents during deposition. Juvenile material is dominantly present as blocky fine ash and finely vesiculated fine to coarse lapilli pumice. This indicates that phreatomagmatic fragmentation was predominant, but also that the magma was volatile-rich and vesiculating at the time of eruption. This is the first study to document a significant magmatic volatile component in an NVF maar-diatreme eruption. The top of the phreatomagmatic sequence abruptly contacts the overlying minette lava flows, indicating no gradual drying-out period between the explosive and effusive phases. The lithology of the accidental clasts is consistent throughout the vertical pyroclastic

  5. Tectonic Evolution of the Jurassic Pacific Plate

    NASA Astrophysics Data System (ADS)

    Nakanishi, M.; Ishihara, T.

    2015-12-01

    We present the tectonic evolution of the Jurassic Pacific plate based on magnetic anomly lineations and abyssal hills. The Pacific plate is the largest oceanic plate on Earth. It was born as a microplate aroud the Izanagi-Farallon-Phoenix triple junction about 192 Ma, Early Jurassic [Nakanishi et al., 1992]. The size of the Pacific plate at 190 Ma was nearly half that of the present Easter or Juan Fernandez microplates in the East Pacific Rise [Martinez et at, 1991; Larson et al., 1992]. The plate boundary surrounding the Pacific plate from Early Jurassic to Early Cretaceous involved the four triple junctions among Pacific, Izanagi, Farallon, and Phoenix plates. The major tectonic events as the formation of oceanic plateaus and microplates during the period occurred in the vicinity of the triple junctions [e.g., Nakanishi and Winterer, 1998; Nakanishi et al., 1999], implying that the study of the triple junctions is indispensable for understanding the tectonic evolution of the Pacific plate. Previous studies indicate instability of the configuration of the triple junctions from Late Jurassic to Early Cretaceous (155-125 Ma). On the other hand, the age of the birth of the Pacific plate was determined assuming that all triple junctions had kept their configurations for about 30 m.y. [Nakanishi et al., 1992] because of insufficient information of the tectonic history of the Pacific plate before Late Jurassic.Increase in the bathymetric and geomagnetic data over the past two decades enables us to reveal the tectonic evolution of the Pacific-Izanagi-Farallon triple junction before Late Jurassic. Our detailed identication of magnetic anomaly lineations exposes magnetic bights before anomaly M25. We found the curved abyssal hills originated near the triple junction, which trend is parallel to magnetic anomaly lineations. These results imply that the configuration of the Pacific-Izanagi-Farallon triple junction had been RRR before Late Jurassic.

  6. Decolonizing the Navajo Nation: The Lessons of the Naabaahii

    ERIC Educational Resources Information Center

    Lee, Lloyd L.

    2011-01-01

    This paper discusses ways Dine peoples can use cultural knowledge to rebuild and decolonize the Navajo Nation. In the past, leaders, warriors, and all peoples worked together to sustain their community's way of life. These stories and strategies can be helpful in rectifying and resolving many challenges and problems Dine peoples face in the…

  7. Prospects for the Survival of the Navajo Language: A Reconsideration.

    ERIC Educational Resources Information Center

    Spolsky, Bernard

    2002-01-01

    Discusses endangerment of the Navajo language, blaming schooling, but noting several other factors that weaken language loyalty. Explains that vernacular literacy, traditional and introduced religion, and political structure have failed to establish a counterforce to language loss. Economic changes have led to new living patterns that, together…

  8. Indian Reservation Labor Markets: A Navajo Assessment and Challenge.

    ERIC Educational Resources Information Center

    Pottinger, Richard

    1985-01-01

    Assesses report by 1983 Commission on Indian Reservation Economies, which links slow economic growth on Indian reservations to lack of education. Contradicts report's conclusions using data from Navajo reservation. Examines apparent federal assumptions regarding reservation economies. Challenges these assumptions and suggests alternative approach…

  9. Prevalence of Hepatitis A Virus Antibody Among Navajo School Children.

    ERIC Educational Resources Information Center

    Williams, Robert

    1986-01-01

    A serologic investigation of prevalence of immunity to hepatitis A (anti-HAV) was conducted in a rural school adjacent to a Navajo reservation in New Mexico. The results show rates of anti-HAV that are the highest reported at the ages tested in any subpopulation in the United States, comparable only with those in developing countries. (KH)

  10. The Navajo Way: From High School to College.

    ERIC Educational Resources Information Center

    Noon, John

    Written for college-bound Navajo high school seniors and dedicated to all Native Americans, this guide presents information relative to preparation for college entrance. The following topics are discussed in detail: (1) choosing a college (financial help, college major, college size, the minority population at college, community size, and personal…

  11. The Man from South: Reconsidering Navajo Students' Stories.

    ERIC Educational Resources Information Center

    Benjamin, Rebecca

    1995-01-01

    Analyzes the structural and thematic elements of three stories written by a sixth-grade Navajo girl to challenge the notion that a linear pattern of growth is followed by all children as they learn to write stories. The results question the assumption that certain kinds of narratives and their American Indian authors are less able or less…

  12. Navajo Uranium Education Programs: The Search for Environmental Justice

    ERIC Educational Resources Information Center

    Charley, Perry H.; Dawson, Susan E.; Madsen, Gary E.; Spykerman, Bryan R.

    2004-01-01

    Uranium mining and milling in the Four Corners' area of the American Southwest has had serious negative impacts on American Indian workers, their families, and their communities. In this article, we will examine Navajo education programs which inform citizens about risks and health impacts associated with radiation exposures. Because the Navajo…

  13. Eyewitness Reporting by Navajo and Mainstream-Culture Children.

    ERIC Educational Resources Information Center

    Lindstedt, D. Elise

    2000-01-01

    This study compared cultural differences in the eyewitness reporting of Navajo and mainstream-culture third graders who were questioned 10 days after an event. Mainstream-culture children reported more information overall but the groups did not differ in accuracy. Active participation affected the amount of information reported by…

  14. Career Unit. The Art of Navajo Rug Weaving.

    ERIC Educational Resources Information Center

    Robb, Edna; And Others

    This career exploration instructional unit on Navajo rug weaving is one of several resulting from the rural southwestern Colorado CEPAC Project (Career Education Process of Attitude Change). This unit consists of (1) five unit objectives (to recognize the importance of sheep in the Indians' life, to realize the time required to prepare wool for…

  15. Classroom Inquiry and Navajo Learning Styles: A Call for Reassessment.

    ERIC Educational Resources Information Center

    McCarty, T. L.; And Others

    1991-01-01

    Describes experimental K-9 bilingual-bicultural curriculum in Navajo studies emphasizing open-ended questioning, inductive/analytical reasoning, and student verbalization in both small and large groups, and discusses reasons why it has been well received by teachers and students. Findings challenge conventional view that these students are…

  16. Learning to Construct Verbs in Navajo and Quechua

    ERIC Educational Resources Information Center

    Courtney, Ellen H.; Saville-Troike, Muriel

    2002-01-01

    Navajo and Quechua, both languages with a highly complex morphology, provide intriguing insights into the acquisition of inflectional systems. The development of the verb in the two languages is especially interesting, since the morphology encodes diverse grammatical notions, with the complex verb often constituting the entire sentence. While the…

  17. Successful newborn screening for SCID in the Navajo Nation.

    PubMed

    Kwan, Antonia; Hu, Diana; Song, Miran; Gomes, Heidi; Brown, Denise R; Bourque, Trudy; Gonzalez-Espinosa, Diana; Lin, Zhili; Cowan, Morton J; Puck, Jennifer M

    2015-05-01

    Newborn screening (NBS) for severe combined immunodeficiency (SCID) identifies affected infants before the onset of life-threatening infections, permitting optimal treatment. Navajo Native Americans have a founder mutation in the DNA repair enzyme Artemis, resulting in frequent Artemis SCID (SCID-A). A pilot study at 2 Navajo hospitals assessed the feasibility of SCID NBS in this population. Dried blood spots from 1800 infants were assayed by PCR for T-cell receptor excision circles (TRECs), a biomarker for naïve T cells. Starting in February 2012, TREC testing transitioned to standard care throughout the Navajo Area Indian Health Service, and a total of 7900 infants were screened through July 2014. One infant had low TRECs and was diagnosed with non-SCID T lymphopenia, while 4 had undetectable TRECs due to SCID-A, all of whom were referred for hematopoietic cell transplantation. This report establishes the incidence of SCID-A and demonstrates effectiveness of TREC NBS in the Navajo. PMID:25762520

  18. Participation Structure as Cultural Schema: Examples from a Navajo Preschool.

    ERIC Educational Resources Information Center

    Field, Margaret

    1998-01-01

    Examines the relationship between macro and micro perspectives on the organization of participation structure, and considers how both perspectives can be useful to the ethnographer of interaction. Examples are drawn from a study of Navajo preschool and supported by a substantial body of classroom ethnography in other Native-American communities.…

  19. Evaluation of Navajo Community College, Summary. Final Report June, 1971.

    ERIC Educational Resources Information Center

    Pacific Training and Technical Assistance Corp., Berkeley, CA.

    The final report represented a culmination of a 2 year assessment of the operation and impact of the first institution of higher learning under Indian control, Navajo Community College (CC) at Many Farms, Arizona. The major portion of the data were collected from July, 1970 - May, 1971, although conclusions can be based on evaluation which began…

  20. 75 FR 71138 - Land Acquisitions; Navajo Nation, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Bureau of Indian Affairs Land Acquisitions; Navajo Nation, Arizona AGENCY: Bureau of Indian Affairs... made a final agency determination to acquire approximately 405.61 acres of land into trust for the... notice be given to the public of the Secretary's decision to acquire land in trust at least 30 days...

  1. The Derivation of Meaning in the Navajo Verb.

    ERIC Educational Resources Information Center

    Young, Robert W.

    Lexical derivation in the Navajo verb system is described, with examples. Derivation involves four broad processes: (1) straightforward use of verbal roots and adverbial-derivational prefixes, with their base meanings; (2) extension of base root meaning, often by metaphor, to permit application to disparate concepts; (3) figurative use of…

  2. Politics of Local Control: Ramah Navajo Community Forms a School.

    ERIC Educational Resources Information Center

    Norris, Robert

    For more than 100 years the Native Americans of the U.S. have been dominated economically, socially, educationally, and culturally by the larger society in which they live. The U.S. government has set policies, primarily through the Bureau of Indian Affairs (BIA), without consulting Native Americans. The Ramah Navajo Community experienced…

  3. Mitigating Barriers to Navajo Students' Success in English Courses.

    ERIC Educational Resources Information Center

    Thurston, Kay

    1998-01-01

    Discusses the tremendous barriers to success in college that Navajo students face. Discusses five major forms: financial difficulty, family obligations, prescriptive attitudes toward Standard American English, instructor/faculty ethnocentrism, and ambivalence toward Western education. Discusses ways faculty can work to mitigate these barriers as…

  4. Ethnic Identity and Psychosocial Functioning in Navajo Adolescents

    ERIC Educational Resources Information Center

    Jones, Matthew D.; Galliher, Renee V.

    2007-01-01

    The current study assessed associations among theoretically driven measures of ethnic identity and psychosocial adjustment among 137 Navajo adolescents. For both sexes, measures of students' sense of affirmation and belonging to their ethnic heritage emerged as a strong predictor of positive psychosocial functioning. Less-consistent patterns of…

  5. Of Saints and Lamanites: An Analysis of Navajo Mormonism.

    ERIC Educational Resources Information Center

    Pavlik, Steve

    1992-01-01

    Many Navajos have affiliated with the Mormon church because of the inherent place of Native Americans in church doctrine, the church's opposition to alcohol, deterioration of tribal social order, Mormon tolerance of Indian culture, and material benefits of church association, including the Indian Student Placement Program. Contains 55 references.…

  6. Upper Jurassic ramp carbonate and associated evaporite, Neuquen Province, Argentina

    SciTech Connect

    Nickelsen, B.H.; Merrill, D.A.

    1986-05-01

    The Oxfordian La Manga Limestone (10-65 m) and overlying Auquilco Gypsum (315 m maximum thickness) crop out along the west flank of the Neuquen basin, Neuquen Province, Argentina (36/sup 0/40/sup 0/S lat.). The contact with the underlying Lotena Sandstone is gradational, and both formations are cut by the Late Jurassic Araucanian angular unconformity. Seven lithofacies have been identified within sections measured through the entire interval along the northeast to southwest trending, 30-km long Sierra de la Vaca Muerta ridge (38/sup 0/30'-39/sup 0/S). The La Manga Limestone is interpreted as a temperate ramp carbonate that developed over the Lotena Formation siliciclastic shelf. Interpretations of lithofacies from southwest to northeast are: behind-barrier subtidal lagoon with washovers; coral and red algae biostromes; ooid and peloid sand shoals; downslope wackestone and packstone mud mounds; and deep-water carbonate turbidites. A minor regression separates La Manga and Auquilco Formations. Lithofacies of the Auquilco Formation indicate a shallowing-up sequence comprised of initially deep (hundreds of meters) subaqueous evaporite deposition followed by shallow, subtidal carbonate peloidal and shell fragment grainstones and evaporites. Thickness of the subaqueous evaporite gives an order of magnitude estimate of Auquilco basin depths of a few hundred meters at most. The Neuquen basin has an intermediate proportion of carbonate in comparison to relatively carbonate-poor basins to the south and carbonate-rich basins to the north.

  7. Salinity increases in the navajo aquifer in southeastern Utah

    USGS Publications Warehouse

    Naftz, D.L.; Spangler, L.E.

    1994-01-01

    Salinity increases in water in some parts of the Navajo aquifer in southeastern Utah have been documented previously. The purpose of this paper is to use bromide, iodide, and chloride concentrations and del oxygen-18 and deuterium values in water from the study area to determine if oil-field brines (OFB) could be the source of increased salinity. Mixing-model results indicate that the bromide-to-chloride X 10,000 weight ratio characteristic of OFB in and outside the study area could not be causing the bromide depletion with increasing salinity in the Navajo aquifer. Mixing-model results indicate that a mixture of one percent OFB with 99 percent Navajo aquifer water would more than double the bromide-to-chloride weight ratio, instead of the observed decrease in the weight ratio with increasing chloride concentration. The trend of the mixing line representing the isotopically enriched samples from the Navajo aquifer does not indicate OFB as the source of isotopically enriched water; however, the simulated isotopic composition of injection water could be a salinity source. The lighter isotopic composition of OFB samples from the Aneth, Ratherford, White Mesa Unit, and McElmo Creek injection sites relative to the Ismay site is a result of continued recycling of injection water mixed with various proportions of isotopically lighter make-up water from the alluvial aquifer along the San Juan River. A mixing model using the isotopic composition of the simulated injection water suggests that enriched samples from the Navajo aquifer are composed of 36 to 75 percent of the simulated injection water. However, chloride concentrations predicted by the isotopic mixing model are up to 13.4 times larger than the measured chloride concentrations in isotopically enriched samples from the Navajo aquifer, indicating that injection water is not the source of increased salinity. Geochemical data consistently show that OFB and associated injection water from the Greater Aneth Oil Field

  8. Geohydrology and effects of water use in the Black Mesa area, Navajo and Hopi Indian Reservations, Arizona

    USGS Publications Warehouse

    Eychaner, James H.

    1981-01-01

    The main source of water in the 5,400-square-mile Black Mesa area is the N aquifer, which consists of the Navajo Sandstone and underlying Kayenta Formation and Wingate Sandstone. Water is under confined conditions in the central 3,300 square miles. Transmissivity is less than 1,000 feet squared per day. Storage coefficient is less than 0.0004 in the confined part of the aquifer and at least 0.1 in the unconfined part. Recharge is about 13,000 acre-feet per year, and storage at equilibrium, which was before 1965, was at least 180 million acre-feet. Ground-water withdrawals were less than 400 acre-feet per year before 1970 and increased to 5,300 acre-feet per year 1976-1979. By 1980, municipal-supply pumpage is expected to exceed that for a coal-slurry pipeline. Water levels have declined throughout the confined part of the aquifer. Decline of more than 100 feet was calculated for an area of 200 square miles through 1979 and was projected for 440 square miles through 2001. In the unconfined part, project declines averaged less than 1 foot. If pumping for coal slurry stopped, most of the decline would recover within 10 years. (USGS)

  9. Sequence stratigraphy of the Kingak Shale (Jurassic-Lower Cretaceous), National Petroleum Reserve in Alaska

    USGS Publications Warehouse

    Houseknecht, D.W.; Bird, K.J.

    2004-01-01

    Beaufortian strata (Jurassic-Lower Cretaceous) in the National Petroleum Reserve in Alaska (NPRA) are a focus of exploration since the 1994 discovery of the nearby Alpine oil field (>400 MMBO). These strata include the Kingak Shale, a succession of depositional sequences influenced by rift opening of the Arctic Ocean Basin. Interpretation of sequence stratigraphy and depositional facies from a regional two-dimensional seismic grid and well data allows the definition of four sequence sets that each displays unique stratal geometries and thickness trends across NPRA. A Lower to Middle Jurassic sequence set includes numerous transgressive-regressive sequences that collectively built a clastic shelf in north-central NPRA. Along the south-facing, lobate shelf margin, condensed shales in transgressive systems tracts downlap and coalesce into a basinal condensed section that is likely an important hydrocarbon source rock. An Oxfordian-Kimmeridgian sequence set, deposited during pulses of uplift on the Barrow arch, includes multiple transgressive-regressive sequences that locally contain well-winnowed, shoreface sandstones at the base of transgressive systems tracts. These shoreface sandstones and overlying shales, deposited during maximum flooding, form stratigraphic traps that are the main objective of exploration in the Alpine play in NPRA. A Valanginian sequence set includes at least two transgressive-regressive sequences that display relatively distal characteristics, suggesting high relative sea level. An important exception is the presence of a basal transgressive systems tract that locally contains shoreface sandstones of reservoir quality. A Hauterivian sequence set includes two transgressive-regressive sequences that constitute a shelf-margin wedge developed as the result of tectonic uplift along the Barrow arch during rift opening of the Arctic Ocean Basin. This sequence set displays stratal geometries suggesting incision and synsedimentary collapse of the shelf

  10. Risk factors for invasive pneumococcal disease among Navajo adults.

    PubMed

    Watt, James P; O'Brien, Katherine L; Benin, Andrea L; McCoy, Sandra I; Donaldson, Connie M; Reid, Raymond; Schuchat, Anne; Zell, Elizabeth R; Hochman, Michael; Santosham, Mathuram; Whitney, Cynthia G

    2007-11-01

    Invasive pneumococcal disease (IPD) is 3-5 times more common among Navajo adults than in the general US population. The authors conducted a case-control study to identify risk factors for IPD among Navajo adults. Navajos aged > or =18 years with IPD were identified through prospective, population-based active laboratory surveillance (December 1999-February 2002). Controls matched to cases on age, gender, and neighborhood were selected. Risk factors were identified through structured interviews and medical record reviews. The authors conducted a matched analysis based on 118 cases and 353 controls. Risk factors included in the final multivariable analysis were chronic renal failure (odds ratio (OR) = 2.6, 95% confidence interval (CI): 0.9, 7.7), congestive heart failure (OR = 5.6, 95% CI: 2.2, 14.5), self-reported alcohol use or alcoholism (OR = 2.9, 95% CI: 1.5, 5.4), body mass index (weight (kg)/height (m)(2)) <5th (OR = 3.2, 95% CI: 1.0, 10.6) or >95th (OR = 2.8, 95% CI: 1.0, 8.0) percentile, and unemployment (OR = 2.6, 95% CI: 1.2, 5.5). The population attributable fractions were 10% for chronic renal failure, 18% for congestive heart failure, 30% for self-reported alcohol use or alcoholism, 6% for body mass index, and 20% for unemployment. Several modifiable risk factors for IPD in Navajos were identified. The high prevalence of renal failure, alcoholism, and unemployment among Navajo adults compared with the general US population may explain some of their increased risk of IPD. PMID:17693393

  11. The Lower Cretaceous Chouf Sandstone of Lebanon: is it a syn-rift clastic sequence?

    NASA Astrophysics Data System (ADS)

    Hatzenbichler, Georg; Bauer, Harald; Grasemann, Bernhard; Tari, Gabor; Nader, Fadi H.; Church, Jonathan; Schneider, Dave

    2013-04-01

    The lowermost unit of the Cretaceous succession onshore Lebanon is a widespread prominent sandstone formation traditionally known as the "Grès de Base". The Chouf Sandstone is one of the most distinctive geologic units in Lebanon and is extensively quarried as building sand. The formation commonly consists of a brown to white sandstone with associated claystones, shales, locally volcanics and lignites. Based on outcrop samples taken in the central and northern parts of Mount Lebanon the petrographical composition of the typical Chouf Sandstone is dominated by monocrystalline quartz (85-95%) indicating a well-sorted sandstone. Sedimentological observations suggest deposition of the formation was typically in fluvial, coastal plain and deltaic environments. The Chouf Sandstone is variable in thickness, ranging from a few metres to 300 m. In certain areas rapid lateral thickness changes have been reported which may reflect a paleo-topography or syn-depositional block faulting. Similar thickness variations in the underlying Upper Jurassic formations might be interpreted as the result of syn-rift normal faulting. In order to test the syn-rift nature of the Chouf Sandstone, modern high-resolution satellite data sets (with ~ 0.75 m horizontal and 4 m vertical resolution) were used to derive thickness data points for the Chouf Sandstone in NW Lebanon. One important reason to use high-resolution satellite data for onshore Lebanon is the general lack of structural measurements on the existing vintage geologic maps. In lieu of these basic data, the common surface point method was used to derive this information in a consistent manner across the study area. First results obtained by remote sensing techniques do reveal local variations in the thickness of the Chouf Sandstone, on order of tens to hundreds of meters. These isopach variations in a map-view sense are interpreted to be the result of deposition in individual extensional half-grabens in a much larger overall basin

  12. A quantitative model of ground-water flow during formation of tabular sandstone uranium deposits

    USGS Publications Warehouse

    Sanford, R.F.

    1994-01-01

    Presents a quantitative simulation of regional groundwater flow during uranium deposition in the Westwater Canyon Member and Jackpile Sandstone Member of the Upper Jurassic Morrison Formation in the San Juan basin. Topographic slope, shoreline position, and density contrasts in the lake and pore fluids controlled the directions of flow and recharge-discharge areas. The most important results for uranium ore deposit formation are that regional groundwater discharged throughout the basin, regional discharge was concentrated along the shore line or playa margin, flow was dominantly gravity driven, and compaction dewatering was negligible. A strong association is found between the tabular sandstone uranium deposits and major inferred zones of mixed local and regional groundwater discharge. -from Author

  13. Dine bikeyah bik'ah (Navajo oil): An ethnohistory, 1922-1960

    NASA Astrophysics Data System (ADS)

    Chamberlain, Kathleen Patricia

    1998-11-01

    Oil was discovered on the Navajo reservation in 1922, and as a result, the U.S. Department of the Interior pressured Navajos into leasing their lands to develop it. This study reveals that, at first, government officials hoped Navajos would quietly acquiesce, but instead Navajos fought for control. Moreover, oil development served as a basis for tribal debates over such issues as assimilation, land use, and the environment, especially the destruction of grazing areas and sacred sites. Manuscript collections and federal government documents provided the minutes of many tribal council meetings from 1923 to 1960, correspondence between Navajo, Interior Department, and oil company personnel, and royalty and leasing data. Research revealed a tremendous diversity of opinion not only between Navajos and non-Navajos, but between Navajos themselves. Interviews conducted in Farmington, Aztec, Gallup, and Albuquerque, New Mexico, added further complexity and provided local "color." The main difficulty, of course, was locating the Navajo voice and particularly the voices of those not involved in tribal government. A second problem was the paucity of accurate production and royalty documents. Oil company reports were not subject to verification during this period, so it is unlikely that those available provide correct figures. Moreover, oil companies deny possessing archives. This study attempts to balance Navajo and non-Navajo responses to oil development on reservation land from 1922 to 1960 and to suggest future research beyond this period. When dealing with two very diverse cultures, however, there is a tendency to vilify one of them and to examine the other uncritically, perhaps even romantically. Research revealed many complex individuals within both cultures, men and women with varying ambitions and viewpoints. This study presents a tumultuous period in Navajo history and focuses on the successes and failures, abilities and weaknesses of both Navajos and Anglo-Americans.

  14. Operation Sandstone: 1948. Technical report

    SciTech Connect

    Berkhouse, L.H.; Hallowell, J.H.; McMullan, F.W.; Davis, S.E.; Jones, C.B.

    1983-12-19

    SANDSTONE was a three-detonation atmospheric nuclear weapon test series conducted during the spring of 1948 at Enewetak Atoll in the Marshall Islands. Report emphasis is on the radiological safety of the personnel. Available records on personnel exposure are summarized.

  15. A New Classification of Sandstone.

    ERIC Educational Resources Information Center

    Brewer, Roger Clay; And Others

    1990-01-01

    Introduced is a sandstone classification scheme intended for use with thin-sections and hand specimens. Detailed is a step-by-step classification scheme. A graphic presentation of the scheme is presented. This method is compared with other existing schemes. (CW)

  16. "Still, She Didn't See What I Was Trying to Say": Towards a History of Framing Navajo English in Navajo Written Poetry

    ERIC Educational Resources Information Center

    Webster, Anthony K.

    2010-01-01

    This paper outlines the ways that Navajo poetry was framed in the late 1960s and early 1970s, as "unsophisticated" and non-literary by the introductory materials written by non-Native Americans for collections of Native American poetry. At issue was a view that saw the use of Navajo English, a distinctive vernacular dialect, as a deficient form of…

  17. Lessons from the Navajo: Assistance with Environmental Data Collection Ensures Cultural Humility and Data Relevance

    PubMed Central

    deLemos, Jamie; Rock, Tommy; Brugge, Doug; Slagowski, Naomi; Manning, Thomas; Lewis, Johnnye

    2008-01-01

    Background The Navajo Nation suffers from a legacy of environmental pollution from historical uranium mining activities, resulting in adverse public health outcomes and continuous exposure. Objective Partner with a Navajo graduate student and community members in a field campaign to characterize the spatial distribution and geochemistry of uranium for a multipathway uranium exposure assessment under development by the Dine Network for Environmental Health (DiNEH) project. Methods Attend community meetings, acquire Navajo language skills, and integrate local knowledge into sampling approach of sediment, water, and vegetation. Results Navajo participation (1) helped to foster trust in research efforts during community interactions, (2) taught aspects of Navajo culture and language to maintain positive and respectful relations, and (3) conveyed information on Navajo culture that would impact sampling strategies. Conclusions Community engagement helps to sustain equitable partnerships and aids in culturally appropriate, relevant data collection. PMID:19655034

  18. Coping with arsenic-based pesticides on Dine (Navajo) textiles

    NASA Astrophysics Data System (ADS)

    Anderson, Jae R.

    Arsenic-based pesticide residues have been detected on Arizona State Museum's (ASM) Dine (Navajo) textile collection using a handheld portable X-ray (pXRF) spectrometer. The removal of this toxic pesticide from historic textiles in museums collections is necessary to reduce potential health risks to Native American communities, museum professionals, and visitors. The research objective was divided into three interconnected stages: (1) empirically calibrate the pXRF instrument for arsenic contaminated cotton and wool textiles; (2) engineer an aqueous washing treatment exploring the effects of time, temperature, agitation, and pH conditions to efficiently remove arsenic from wool textiles while minimizing damage to the structure and properties of the textile; (3) demonstrate the devised aqueous washing treatment method on three historic Navajo textiles known to have arsenic-based pesticide residues. The preliminary results removed 96% of arsenic from a high arsenic concentration (~1000 ppm) textile opposed to minimal change for low arsenic concentration textiles (<100 ppm).

  19. Navajo Generating Station and Air Visibility Regulations: Alternatives and Impacts

    SciTech Connect

    Hurlbut, D. J.; Haase, S.; Brinkman, G.; Funk, K.; Gelman, R.; Lantz, E.; Larney, C.; Peterson, D.; Worley, C.; Liebsch, E.

    2012-01-01

    Pursuant to the Clean Air Act, the U.S. Environmental Protection Agency (EPA) announced in 2009 its intent to issue rules for controlling emissions from Navajo Generating Station that could affect visibility at the Grand Canyon and at several other national parks and wilderness areas. The final rule will conform to what EPA determines is the best available retrofit technology (BART) for the control of haze-causing air pollutants, especially nitrogen oxides. While EPA is ultimately responsible for setting Navajo Generating Station's BART standards in its final rule, it will be the U.S. Department of the Interior's responsibility to manage compliance and the related impacts. This study aims to assist both Interior and EPA by providing an objective assessment of issues relating to the power sector.

  20. Discovering the "-Ologies" on the Jurassic Coast

    ERIC Educational Resources Information Center

    Peacock, Alan

    2007-01-01

    The Jurassic Coast is Britain's only natural World Heritage site, a tangible time-line that takes one through 185 million years of history in 95 miles of coast. It provides individuals with a world-famous educational resource and an unrivalled outdoor classroom that has played a key role in the study of earth sciences. The author is keen to ignite…

  1. Jurassic stratigraphy of the Wiggins Arch, Mississippi

    SciTech Connect

    Rhodes, J.A.; Maxwell, G.B. )

    1993-09-01

    Mobil and Shell jointly explored the Wiggins arch area in southern Mississippi from 1985 to 1991. The effort concentrated on the Jurassic Norphlet and Smackover formations. Two wells were drilled into Paleozoic crystalline rocks and one well into the Pine Hill formation. Two of these wells were located on the southern side of the Wiggins arch and provide significant data for interpreting Jurassic stratigraphy. The Mobil No. 1 U.S.A. well encountered a complete Jurassic section, but with some significantly different facies than those encountered by wells to the north. A granite wash section is the equivalent to the Frisco City formation previously only found 100 mi to the north-northeast. All 300 ft of Smackover is crystalline dolomite. The Norphlet section is entirely granite wash. The Pine Hill anhydrite is unusually thick and interpreted to be equivalent to the Louann Salt. Correlations to other wells on the Wiggins arch, particularly the Conoco No. 1 Higgins, indicate that the Jurassic can be divided into three transgressive events separated by the Norphlet/Pine Hill and Frisco City/Buckner regressive events.

  2. Jurassic evolution of the Tien-Shan

    SciTech Connect

    Bebeshev, I.I.

    1994-09-01

    Complex studies led to identification of three stages in Jurassic deposits. The stages reflect development periods of the studied deposits. Each stage is represented by a paleogeographic map that indicates the evolution of ancient landforms in the Tien-Shan region in time and space.

  3. New Early Jurassic Tetrapod Assemblages Constrain Triassic-Jurassic Tetrapod Extinction Event

    NASA Astrophysics Data System (ADS)

    Olsen, P. E.; Shubin, N. H.; Anders, M. H.

    1987-08-01

    The discovery of the first definitively correlated earliest Jurassic (200 million years before present) tetrapod assemblage (Fundy basin, Newark Supergroup, Nova Scotia) allows reevaluation of the duration of the Triassic-Jurassic tetrapod extinction event. Present are tritheledont and mammal-like reptiles, prosauropod, theropod, and ornithischian dinosaurs, protosuchian and sphenosuchian crocodylomorphs, sphenodontids, and hybodont, semionotid, and palaeonisciform fishes. All of the families are known from Late Triassic and Jurassic strata from elsewhere; however, pollen and spore, radiometric, and geochemical correlation indicate an early Hettangian age for these assemblages. Because all ``typical Triassic'' forms are absent from these assemblages, most Triassic-Jurassic tetrapod extinctions occurred before this time and without the introduction of new families. As was previously suggested by studies of marine invertebrates, this pattern is consistent with a global extinction event at the Triassic-Jurassic boundary. The Manicouagan impact structure of Quebec provides dates broadly compatible with the Triassic-Jurassic boundary and, following the impact theory of mass extinctions, may be implicated in the cause.

  4. Promise made: The Navajo indian irrigation project and water politics in the American West. Doctoral thesis

    SciTech Connect

    Jacobsen, J.E.

    1989-01-01

    According to the 1962 legislation by which the U.S. Congress authorized the Navajo Indian Irrigation Project (NIIP), a federal reclamation project on the Navajo Reservation in northwest New Mexico, it was to bring economic development to the Navajo Tribe in the form of 18,000 jobs on family farms and related enterprises, all in 14 years. The project is today just over half completed, it is a single corporate agribusiness that employs a few hundred Navajo during the peak harvest season, and there are pressures to reduce the size of the project.

  5. Field manual for the collection of Navajo Nation streamflow-gage data

    USGS Publications Warehouse

    Hart, Robert J.; Fisk, Gregory G.

    2014-01-01

    The Field Manual for the Collection of Navajo Nation Streamflow-Gage Data (Navajo Field Manual) is based on established (standard) U.S. Geological Survey streamflow-gaging methods and provides guidelines specifically designed for the Navajo Department of Water Resources personnel who establish and maintain streamflow gages. The Navajo Field Manual addresses field visits, including essential field equipment and the selection of and routine visits to streamflow-gaging stations, examines surveying methods for determining peak flows (indirect measurements), discusses safety considerations, and defines basic terms.

  6. The Lowell Observatory Navajo-Hopi Astronomy Outreach Program

    NASA Astrophysics Data System (ADS)

    Herrmann, K. A.; Hunter, D. A.; Bosh, A. S.; Johnson, M.; Schindler, K.

    2012-08-01

    We present an overview of the Lowell Observatory Navajo-Hopi Astronomy Outreach Program, which is modeled after the ASP's Project ASTRO (Richter & Fraknoi 1994). Since 1996, our missions have been (1) to use the inherent excitement about the night sky to help teachers get Navajo and Hopi students excited about science and education, and (2) to help teachers of Navajo and Hopi students learn about astronomy and hands-on activities so that they will be better able to incorporate astronomy in their classrooms. Lowell astronomers pair up for a school year with an elementary or middle school (5th-8th grade) teacher and make numerous visits to their teachers' classes, partnering with the educators in leading discussions linked with hands-on activities. Lowell staff also work with educators and amateur astronomers to offer evening star parties that involve the family members of the students as well as the general community. Toward the end of the school year, teachers bring their classes to Lowell Observatory. The classes spend some time exploring the Steele Visitor Center and participating in tours and programs. They also voyage to Lowell's research facility in the evening to observe at two of Lowell's research telescopes. Furthermore, we offer biennial teacher workshops in Flagstaff to provide teachers with tools, curricula materials, and personalized training so that they are able to include astronomy in their classrooms. We also work with tribal educators to incorporate traditional astronomical knowledge. Funding for the program comes from many different sources.

  7. Quantitative analysis of sandstone porosity

    SciTech Connect

    Ferrell, R.E. Jr.; Carpenter, P.K.

    1988-01-01

    A quantitative analysis of changes in porosity associated with sandstone diagenesis was accomplished with digital back-scattered electron image analysis techniques. The volume percent (vol. %) of macroporosity, quartz, clay minerals, feldspar, and other constituents combined with stereological parameters, such as the size and shape of the analyzed features, permitted the determination of cement volumes, the ratio of primary to secondary porosity, and the relative abundance of detrital and authigenic clay minerals. The analyses were produced with a JEOL 733 Superprobe and a TRACOR/NORTHERN 5700 Image Analyzer System. The results provided a numerical evaluation of sedimentological facies controls and diagenetic effects on the permeabilities of potential reservoirs. In a typical application, subtle differences in the diagnetic development of porosity were detected in Wilcox sandstones from central Louisiana. Mechanical compaction of these shoreface sandstones has reduced the porosity to approximately 20%. In most samples with permeabilities greater than 10 md, the measured ratio of macroporosity to microporosity associated with pore-filling kaolinite was 3:1. In other sandstones with lower permeabilities, the measured ratio was higher, but the volume of pore-filling clay was essentially the same. An analysis of the frequency distribution of pore diameters and shapes revealed that the latter samples contained 2-3 vol% of grain-dissolution or moldic porosity. Fluid entry to these large pores was restricted and the clays produced from the grain dissolution products reduced the observed permeability. The image analysis technique provided valuable data for the distinction of productive and nonproductive intervals in this reservoir.

  8. South and North Barents Triassic-Jurassic total petroleum system of the Russian offshore Arctic

    USGS Publications Warehouse

    Lindquist, Sandra J.

    1999-01-01

    One major gas-prone petroleum system characterizes the sparsely explored South and North Barents Basin Provinces of the Russian Arctic in the eastern Barents Sea. More than 13 billion barrels of oil equivalent (79 trillion cubic feet of gas) known ultimately recoverable gas reserves in seven fields were sourced from Triassic marine and continental shales and stored in Jurassic (97%) and Triassic (3%) marine and continental sandstone reservoir rocks. The basins contain 18-20 kilometers of pre-Upper Permian carbonate and post-Upper Permian siliciclastic sedimentary fill. Late Permian-Triassic(?) rifting and subsidence resulted in the deposition of as much as 9 kilometers of Triassic strata, locally injected with sills. Rapidly buried Lower Triassic source rocks generated hydrocarbons as early as Late Triassic into stratigraphic traps and structural closures that were modified periodically. Thermal cooling and deformation associated with Cenozoic uplift impacted seal integrity and generation processes, modified traps, and caused gas expansion and remigration.

  9. Up against Giants: The National Indian Youth Council, the Navajo Nation, and Coal Gasification, 1974-77

    ERIC Educational Resources Information Center

    Shreve, Bradley Glenn

    2006-01-01

    In the spring of 1977, members of the National Indian Youth Council (NIYC), along with the Coalition for Navajo Liberation, barraged the Secretary of the Interior and the chairman of the Navajo Nation with petitions calling for a halt to the proposed construction of several coal gasification plants on the Navajo Reservation in northwestern New…

  10. Teenager-, Mother-, Daughter-, Who Am I? Navajo Adolescent Mothers' Perceptions of the Maternal Role & Implications for Child Developmental Outcomes.

    ERIC Educational Resources Information Center

    Dalla, Rochelle L.

    This study explored the meaning of motherhood among Navajo teenagers, their mothers, and community informants living in a small, rural town on a Navajo Reservation. Participating were 8 Navajo teenage mothers ranging from 16 to 19 years, 7 grandmothers (mothers of the teens) who ranged from 41 to 57 years, and 6 community informants: two teachers,…

  11. 25 CFR 161.102 - What notifications are required that tribal laws apply to grazing permits on the Navajo...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws... tribal law or tribal policy that relates to this part. The Navajo Nation must notify BIA of the content... Navajo Nation law on their grazing permits. BIA will: (1) Provide individual written notice; or (2)...

  12. 25 CFR 161.102 - What notifications are required that tribal laws apply to grazing permits on the Navajo...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws... tribal law or tribal policy that relates to this part. The Navajo Nation must notify BIA of the content... Navajo Nation law on their grazing permits. BIA will: (1) Provide individual written notice; or (2)...

  13. 25 CFR 161.102 - What notifications are required that tribal laws apply to grazing permits on the Navajo...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws... tribal law or tribal policy that relates to this part. The Navajo Nation must notify BIA of the content... Navajo Nation law on their grazing permits. BIA will: (1) Provide individual written notice; or (2)...

  14. 25 CFR 161.102 - What notifications are required that tribal laws apply to grazing permits on the Navajo...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws... tribal law or tribal policy that relates to this part. The Navajo Nation must notify BIA of the content... Navajo Nation law on their grazing permits. BIA will: (1) Provide individual written notice; or (2)...

  15. 25 CFR 161.102 - What notifications are required that tribal laws apply to grazing permits on the Navajo...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws... tribal law or tribal policy that relates to this part. The Navajo Nation must notify BIA of the content... Navajo Nation law on their grazing permits. BIA will: (1) Provide individual written notice; or (2)...

  16. Students' Perspectives on Navajo Language and Learning: Voices of the Students

    ERIC Educational Resources Information Center

    Shepard, Marlena

    2012-01-01

    To determine if Navajo language classes made a difference in students' lives, thirty Navajo language and culture students were selected to be interviewed. The students selected were those who were in the language and culture programs in the elementary, middle and high school. The focus was to find out the students' perspectives on Navajo…

  17. The Navajo Nation: An American Colony. A Report of the United States Commission on Civil Rights.

    ERIC Educational Resources Information Center

    McCabe, Carol J.; Lewis, Hester

    The major portion of this report is devoted to the Anglo and American Indian testimony from the 1973 Commission on Civil Rights Hearings on Navajo economic development, employment, education, and health care. Among the major recommendations cited are those calling for: (1) legal recognition of the Navajo Tribal Council to provide for favorable tax…

  18. "Please Read Loose": Intimate Grammars and Unexpected Languages in Contemporary Navajo Literature

    ERIC Educational Resources Information Center

    Webster, Anthony K.

    2011-01-01

    This paper uses Philip Deloria's "Indians in Unexpected Places" as a lens by which to understand the expectations and reviews of Navajo author Blackhorse Mitchell's "Miracle Hill." Written in Navajo English, the book, from an introduction by T. D. Allen to a number of reviews of the book in the popular press, consistently misrecognized the…

  19. Comparison of Native American Navajo Bender-Gestalt Performance with Koppitz and Sompa Norms.

    ERIC Educational Resources Information Center

    Moore, Clay L.; Zarske, John A.

    1984-01-01

    Compared Bender-Gestalt performance of 452 Navajo children with 1974 Koppitz and System of Multicultural Pluralistic Assessment norms (SOMPA), and investigated the use of the Bender-Gestalt for diagnosing learning disabilities. Results suggested the Koppitz and SOMPA White norms may be useful in psychological assessment of Navajo children. (JAC)

  20. The Circulation and Silence of Weaving Knowledge in Contemporary Navajo Life

    ERIC Educational Resources Information Center

    Yohe, Jill Ahlberg

    2012-01-01

    This article draws upon ethnographic fieldwork within a Navajo community to illustrate how weaving knowledge and practices shape contemporary notions of community identity and belonging. The ongoing exchange of Navajo weaving taboos and the careful management of weaving teachings offers community members various opportunities to share and keep…

  1. A Dine (Navajo) Perspective on Self-Determination: An Exposition of an Egalitarian Place

    ERIC Educational Resources Information Center

    Manuelito, Kathryn D.

    2006-01-01

    Worldview of any culture and society is explicated through epistemological principles that frame the way one sees the world. Dine (Navajo) worldview is explicated through epistemology that has been rejected and debased by the dominant society since contact centuries ago. However, enduring powerful Dine (Navajo) worldview persists in contemporary…

  2. Working with Navajo Special Education Students on the Reservation: Cultural Implications.

    ERIC Educational Resources Information Center

    Watt, Carolyn; Sorgnit, Heather; Medina, Catherine; Jennings, Marianne; Heimbecker, Connie; Gonnie, Pat; Dugi, Audrelia; Bowsley, Virginia; Prater, Greg

    A study in the Kayenta Unified School District (Arizona) on the Navajo Nation--the largest reservation in the United States--examined cultural and language barriers in teaching Navajo special education students. Questionnaires were returned from 26 teachers at all grade levels, and interviews were conducted with 5 teachers and the district…

  3. An Initial Exploration of the Navajo Nation's Language and Culture Initiative.

    ERIC Educational Resources Information Center

    Bachelder, Ann; Markel, Sherry

    This paper presents some preliminary findings from an opinion survey on the nature and depth of language and cultural studies to be included in school curricula as required by the Navajo Tribe's Language and Culture Mandate (1984). A 10-question survey was sent to 20 elementary and secondary schools in the Navajo Nation in New Mexico and Arizona.…

  4. Bilingual Education for American Indians. Vol. II--Navajo. Curriculum Bulletin 13.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Albuquerque, NM.

    Bilingual education for Navajos is the central element in changing education from an alien function to one shared and controlled by the community. A number of community-controlled educational systems have become the driving force in Navajo bilingual education, and the past three years have produced not just higher quanitity, but considerably…

  5. Learning Citizenship for and from Dine Communities: Developing Organic Social Studies Curriculum for the Navajo Nation.

    ERIC Educational Resources Information Center

    Blanchard, Rosemary Ann

    1994-01-01

    Describes a framework for social studies curriculum in Navajo schools that fosters critical citizenship through student research into the physical, historical, economic, political, and cultural dimensions of community life. Aims to promote social studies that reflect the human environment in which Navajo students live and also arm students with…

  6. Dine Baa Hane Bi Naaltsoos: Collected Papers from the Seventh through Tenth Navajo Studies Conferences.

    ERIC Educational Resources Information Center

    Piper, June-el, Ed.

    This document contains 29 papers presented at the 7th-10th Navajo Studies Conferences, 1994-97. The papers are arranged in five sections: "Aesthetics: Rugs, Baskets, and Rock Art"; "Doing Anthropology"; "Health"; "Economics"; and "Contact between Cultures." The papers are: "The First Navajo Studies Conference: Reflections by the Cofounders"…

  7. Teenage Mothering on the Navajo Reservation: An Examination of Intergenerational Perceptions and Beliefs.

    ERIC Educational Resources Information Center

    Dalla, Rochelle L.; Gamble, Wendy C.

    2001-01-01

    A study examined attitudes towards teenage motherhood among 25 Navajo reservation residents, including 8 teenage mothers, their mothers, and 4 teenage fathers. Findings indicate that teenage parenting was discouraged despite the matrilineal nature of Navajo society, men were frequently absent from family life, single maternity was preferable to…

  8. 78 FR 8273 - Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... February 5, 2013 Part III Environmental Protection Agency 40 CFR Part 49 Approval of Air Quality...; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 49 Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for Navajo Generating Station AGENCY: Environmental Protection Agency...

  9. Peoples, Resources, and Lifestyles: The Hopi-Navajo Land Partition Act of 1974.

    ERIC Educational Resources Information Center

    Goodman, James M.

    The Hopi and Navajo tribes have been engaged in a long and complex land dispute within the 1882 Executive Order Area (Joint Use Area) of Arizona, an area recently redefined via the Partition Act of 1974 which calls for the relocation of 5 to 10,000 Navajos. This rearrangement of political domain threatens to influence the future management and…

  10. 25 CFR 161.800 - How does the Navajo Nation provide concurrence to BIA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How does the Navajo Nation provide concurrence to BIA... Nation provide concurrence to BIA? (a) Actions taken by BIA under this part require concurrence of the Navajo Nation under section 640d-9(e)(1)(A) of the Settlement Act. (b) For any action requiring...

  11. 25 CFR 161.800 - How does the Navajo Nation provide concurrence to BIA?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How does the Navajo Nation provide concurrence to BIA... Nation provide concurrence to BIA? (a) Actions taken by BIA under this part require concurrence of the Navajo Nation under section 640d-9(e)(1)(A) of the Settlement Act. (b) For any action requiring...

  12. No One Remembers a Winter Like This: A Year at the Navajo Agency, 1882-1883.

    ERIC Educational Resources Information Center

    Lockard, Louise

    This paper documents a single year in the history of Navajo education from the perspective of the Navajo Agent Dennis Matthew Riordan. It draws on Riordan's correspondence, 1882-83, with the Secretary of the Interior, with Captain Richard Henry Pratt at the Carlisle Indian Industrial School, and with his brother. In December 1882, Riordan arrived…

  13. Cultural and Technical Evaluation of Heating Alternatives to Improve Indoor Air Quality on the Navajo Nation

    EPA Science Inventory

    In the Navajo Nation it is estimated that 62% of households use wood as their primary means of heating1. A 2010 study by the U.S. Geological Survey (USGS) and Diné College found that in Shiprock, NM, the largest town in the Navajo Nation (pop. = 8,300)2, heating is often w...

  14. 78 FR 36716 - Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... FR 8274). List of Subjects in 40 CFR Part 49 Environmental protection, Air pollution control, Indians... X ) from the Navajo Generating Station (NGS), located on the Navajo Nation. EPA provided a three... on the proposed BART determination for NGS. DATES: EPA will announce dates and locations for...

  15. 40 CFR 147.3400 - Navajo Indian lands-Class II wells.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained or inspected at the Navajo Nation... General of the Navajo Nation Pursuant to 40 CFR 145.24”, August 27, 2001. (2) “Statement of the Attorney... reservations (Alamo, Canoncito and Ramah), but excluding the former Bennett Freeze Area, the Four Corners...

  16. 40 CFR 147.3400 - Navajo Indian lands-Class II wells.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained or inspected at the Navajo Nation... General of the Navajo Nation Pursuant to 40 CFR 145.24”, August 27, 2001. (2) “Statement of the Attorney... reservations (Alamo, Canoncito and Ramah), but excluding the former Bennett Freeze Area, the Four Corners...

  17. 40 CFR 147.3400 - Navajo Indian lands-Class II wells.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained or inspected at the Navajo Nation... General of the Navajo Nation Pursuant to 40 CFR 145.24”, August 27, 2001. (2) “Statement of the Attorney... reservations (Alamo, Canoncito and Ramah), but excluding the former Bennett Freeze Area, the Four Corners...

  18. Norms for the Wechsler Intelligence Scale for Children--Revised for Navajo Indians.

    ERIC Educational Resources Information Center

    Tempest, Phyllis; Skipper, Betty

    1988-01-01

    Norms were developed for Navajo Indian students for the Wechsler Intelligence Scale for Children-Revised, by sampling 16 percent of the Navajo school population from first through eighth grade in 8 schools in McKinley County, New Mexico. The norms, based on 539 students, help to separate cultural and language differences from learning…

  19. Bird-like anatomy, posture, and behavior revealed by an early jurassic theropod dinosaur resting trace

    USGS Publications Warehouse

    Milner, A.R.C.; Harris, J.D.; Lockley, M.G.; Kirkland, J.I.; Matthews, N.A.

    2009-01-01

    Background: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. Methodology/Principal Findings: Here we describe a well-preserved theropod trackway in a Lower Jurassic (???198 millionyear- old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. Conclusions/Significance: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods.

  20. Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace

    PubMed Central

    Milner, Andrew R. C.; Harris, Jerald D.; Lockley, Martin G.; Kirkland, James I.; Matthews, Neffra A.

    2009-01-01

    Background Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. Methodology/Principal Findings Here we describe a well-preserved theropod trackway in a Lower Jurassic (∼198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. Conclusions/Significance The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods. PMID:19259260

  1. Depositional setting of the Jurassic Haynesville seismic sequence in the Apalachicola Basin, northeastern Gulf of Mexico

    SciTech Connect

    Dobson, L.M.; Buffler, R.T. )

    1990-05-01

    Seismic and well data from the northeastern Gulf of Mexico were used to define the seismic stratigraphy, geologic history, and depositional setting of the Jurassic (Kimmeridgian) Haynesville sequence in the Apalachicola basin. The data show that Haynesville clastic sedimentation updip was coeval with Haynesville carbonate deposition downdip. The regional Jurassic seismic stratigraphic framework includes, in ascending order, the Louann Salt Norphlet-Smackover, Haynesville, and Cotton Valley sequences. In the vicinity of Destin dome, wells have penetrated Haynesville sandstones, shales, and anhydrites. These clastics correlate with low amplitude, low-continuity reflections that characterize the Haynesville over a broad area updip. Similar reflections within the overlying (Tithonian-earliest Berriasian) Cotton Valley clastic sequence make seismic definition of the top Haynesville sequence boundary difficult updip. As Haynesville clastics are replaced by carbonates downdip, a high amplitude reflection marks the top of the sequence. Haynesville carbonates conformably overlie (Oxfordian) Smackover carbonates in the basin center, and the lower sequence boundary cannot be defined where disrupted by growth faults associated with early movement of the (Callovian ) Louann Salt. Sigmoid clinoforms document Haynesville shelf margin development Seismic facies also include oblique clinoforms that prograde eastward into the basin from the Southern Platform and Middle Ground Arch. No wells penetrate this facies. Mapping of the seismic facies and correlation with well data suggest a depositional setting for the Haynesville sequence in which influx of terrigenous clastics probably derived from adjacent land areas to the north and northeast filled a broad lagoon behind a carbonate shelf margin.

  2. Didactyl Tracks of Paravian Theropods (Maniraptora) from the ?Middle Jurassic of Africa

    PubMed Central

    Mudroch, Alexander; Richter, Ute; Joger, Ulrich; Kosma, Ralf; Idé, Oumarou; Maga, Abdoulaye

    2011-01-01

    Background A new dinosaur tracksite from ?Middle Jurassic sediments of the Irhazer Group on the plains of Agadez (Rep. Niger, northwest Africa) revealed extraordinarily well preserved didactyl tracks of a digitigrade bipedal trackmaker. The distinct morphology of the pes imprints indicates a theropod trackmaker from a paravian maniraptoran closely related to birds. Methodology/Principal Findings The early age and the morphological traits of the tracks allow for description of the new ichnotaxon Paravipus didactyloides. A total of 120 tracks are assigned to 5 individual trackways. The ‘medium-sized’ tracks with an average footprint length of 27.5 cm and footprint width of 23.1 cm are deeply imprinted into the track bearing sandstone. Conclusions/Significance A comparison with other didactyl tracks gives new insights into the foot morphology of advanced maniraptoran theropods and contributes to knowledge of their evolutionary history. The new ichnotaxon takes an important position in the ichnological fossil record of Gondwana and the mid-Jurassic biota worldwide, because it is among the earliest known records of paravian maniraptorans and of didactyl theropod tracks from Africa. PMID:21339816

  3. Jurassic hydrocarbon exploration of southern Florida

    SciTech Connect

    Mitchell-Tapping, H.J.

    1994-09-01

    South Florida Jurassic exploration has been overlooked as a viable exploration target due to lack of data and plate-tectonics application. In Florida, {open_quotes}basement{close_quotes} is defined as crystalline, igneous, metamorphic, and unmetamorphosed sediments of Paleozoic age. Age-dating of zircons has proven that the Florida lower Paleozoic terrane is not akin to that of North America but is part of the West African Guinean shield. Previous published reconstructions of late Paleozoic fits of crustal plates and continents have failed to account for the differences in peninsula Florida basement and the geologic and tectonic continuities of peninsula Florida, Yucatan, Cuba, Hispaniola, and Bahamas. Pre-Atlantic reconstruction of the Gulf of Mexico in this study proposes that there was a Florida connection to Yucatan-Cuba-Africa during the Triassic. This reconstruction also shows that the Jurassic sediments that are well known in the northern Gulf Coast should have been deposited in similar depositional environments in southern Florida. Deep drilling on the Florida peninsula has confirmed this hypothesis. By using plate tectonic reconstruction based on the rising of the North Atlantic Ocean and evidence from petrology of basement samples from deep wells together with petrographic analyses of Jurassic sediments, a Smackover-equivalent exploration play can be developed. Petrographic and petrophysical analysis of these wells that have encountered Jurassic marine shales, anhydrite, dolomite, carbonate, and elastic sediments has determined that these sediments are from shallow-water subtidal, tidal, intertidal, and supratidal environments. Excellent gas shows, oil stain in the pores and high TOC values in the marine shales, indicate that large accumulations of hydrocarbon are present.

  4. Bedrock aquifers in the lower Dirty Devil River basin area, Utah, with special emphasis on the Navajo sandstone

    USGS Publications Warehouse

    Hood, J.W.; Danielson, T.W.

    1981-01-01

    The lower Dirty Devil River basin area in southeastern Utah has an area of about 4,300 square miles (11,140 square kilometers) and ranges in altitude from about 3,700 to more than 11,000 feet (1,130 to 3,350 meters) above mean sea level. Precipitation, the main source of water in the area, ranges from slightly less than 6 inches (152 millimeters) per year in the lowlands to more than 30 inches per year (762 millimeters) in the Henry Mountains and along the western boundary.

  5. Bedrock aquifers in the northern San Rafael Swell area, Utah, with special emphasis on the Navajo Sandstone

    USGS Publications Warehouse

    Hood, J.W.; Patterson, D.J.

    1984-01-01

    The northern San Rafael Swell area in southeastern Utah includes about 2,880 square miles (7,460 square kilometers) and ranges in altitude from about 3,290 to 7,921 feet (1,195 to 2,414 meters). Precipitation, the main source of water in the area, ranges from slightly less than 6 inches (152 millimeters) to slightly more than 12 inches (305 millimeters).

  6. Blueberries on Earth and Mars: Some Correlations Between Andean Paleosols, Geothermal Pipes in Navajo Sandstone and Terra Meridiani on Mars

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Milner, M. W.; Netoff, D. I.; Dohm, J. M.; Sodhi, R. N. S.; Aufreiter, S.; Hancock, R. G. V.; Bezada, M.; Kalm, V.; Malloch, D.

    2006-03-01

    The origin of "blueberries" on Mars and their relationship to similar concretionary forms on Earth invokes a process of variable redox conditions in underground fluids. The possible role of microorganisms in the origin of bluberries opens an avenue for biological investigations.

  7. Iron Isotopes in Spherical Hematite and Goethite Concretions from the Navajo Sandstone (Utah, USA): A Prospective Study for "Martian Blueberries"

    NASA Astrophysics Data System (ADS)

    Busigny, V.; Dauphas, N.

    2006-03-01

    Iron isotopes of terrestrial hematite and goethite concretions provide clues on fluid transport, reservoir sizes, redox variations and biotic versus abiotic processes. This opens several avenues of research for future work on Martian blueberries.

  8. Prevalence of Parkinson Disease Among the Navajo; a Preliminary Examination

    PubMed Central

    Gordon, Paul H.; Zhao, Hongwei; Bartley, Denise; Sims, LT James G.; Begay, Mae-Gilene; Richardson, Sarah Pirio; Lewis, Johnnye; Rowland, Andrew S.

    2014-01-01

    BACKGROUND The prevalence of Parkinson disease (PD) varies by geographic location and ethnicity, but has never been studied among the Navajo. METHODS Period prevalence was calculated using the number of people diagnosed with PD in the Shiprock Service Unit Indian Health Service database during 1995–1999, 2000–2004, and 2005–2009 as the numerator, and the number seen for any reason as the denominator. Age-standardized rates were calculated using the 2000 US population. RESULTS During 2005–2009, 126 people were seen with PD (crude prevalence = 203.7/100,000 population). The age-adjusted rate was 335.9 (95% C. I. 277.8–394.0) overall, 438.5 (95% C.I. 336.5–540.5) in men and 259.7 (95% C.I. 192.8–326.7; p=0.004) in women. The adjusted rate increased with age: 788.8 (95% C.I. 652.0–925.7) for age 40 and above to 1964.9 (95% C.I. 1613.7–2316.1) for age 60 and above. Adjusted rates were 246.6 (95% C.I. 187.2–306.0) in 1995–1999 and 284.7 (95% C.I. 227.0–342.4) in 2000–2004. CONCLUSION Parkinson disease appears common among the Navajo. Estimates increased with age and time, and were higher in men. In-person interviews are needed to confirm these estimates, and to determine incidence, quality of care, and risk factors for PD among the Navajo. PMID:23938348

  9. Irrigation management with remote sensing. [Navajo Indian Irrigation Project

    NASA Technical Reports Server (NTRS)

    Harlan, C.; Heilman, J. L.; Moore, D.; Myers, V. (Principal Investigator)

    1982-01-01

    Two visible/near IR hand held radiometers and a hand held thermoradiometer were used along with soil moisture and lysimetric measurements in a study of soil moisture distribution in afalfa fields on the Navajo Indian Irrigation Project near farmington, New Mexico. Radiances from irrigated plots were measured and converted to reflectances. Surface soil water contents (o cm to 4 cm) were determined gravimetrically on samples collected at the same time as the spectral measurements. The relationship between the spectral measurements and the crop coefficient were evaluated to demonstrate potential for using spectral measurement to estimate crop coefficient.

  10. Characterization of Petroleum Residue in the Entrada Sandstone, Colorado National Monument

    USGS Publications Warehouse

    Lillis, Paul G.; King, J. David

    2007-01-01

    Introduction As part of the U.S. Geological Survey's (USGS) petroleum resource assessment of the Uinta-Piceance Province, Colorado and Utah, in 2000 (USGS Uinta-Piceance Assessment Team, 2003), some 170 oils, oil stains, and oil seeps were geochemically characterized and divided into genetic types (Lillis and others, 2003). Recognized oil types include Minturn, Phosphoria, Grassy Trail Creek, Mancos, Mesaverde, and Green River. Subsequent to that study, the existence and general locality of petroleum residue in the Middle Jurassic Entrada Sandstone in Colorado National Monument (CNM) was brought to the attention of the authors (Scott and others, 2001). Because the analysis of such non-commercial petroleum deposits commonly yields valuable regional resource-trend information, we collected and characterized the reported CNM petroleum residue and compared the results with identified oil types in the Uinta-Piceance Province. Three samples of Entrada Sandstone with petroleum residue were collected near Little Park Road along the south edge of the CNM in sec.20, T.12S., R.101W. The approximate extent of the petroleum staining was determined by field testing with solvent, and the stains appear to be restricted to the upper part of the 'board beds' unit (informal name, Scott and others, 2001) of the Entrada Sandstone between the two fault traces of the Glade Park fault.

  11. Materials Prepared All or in Part as Result of Office of Education Small Research Grant OEG-9-9-120076-0050(057) [To Navajo Community College].

    ERIC Educational Resources Information Center

    Gorman, Howard; And Others

    Through funds provided by the U.S. Office of Education and the Navajo Community College, a major accomplishment was realized in the development of a Navajo Studies Curriculum that reflects the thinking of the Navajos themselves. The most successful aspect of the project was the identification on the part of the Navajos of what they wanted included…

  12. The Navajo Atlas: Environments, Resources, People, and History of the Dine Bikeyah. The Civilization of the American Indian Series, Volume 157.

    ERIC Educational Resources Information Center

    Goodman, James M.

    The 48 maps and descriptive narratives in this atlas of the Navajo Reservation are divided into six sections. Part I, Navajo Country, displays Navajo land in relationship to the United States and the region, and becomes more detailed to place locations within the Dine Bikeyah, or Navajo Land, including administrative and political subdivisions of…

  13. The Law of the People (Dine Bibee Haz'Aannii): A Bicultural Approach to Legal Education for Navajo Students, Volume 2.

    ERIC Educational Resources Information Center

    Vicenti, Dan; And Others

    Volume 2 of a 4-volume bilingual bicultural law-related curriculum deals with the evolution of a Navajo legal system. Navajo "law" was referred to by Navajos as "religion", thus Anglos viewed the Navajo as having no "law." Because of the complexity of this topic, it is suggested that the first sections covering this view be read and digested by…

  14. Paleomagnetic study of Jurassic and Cretaceous rocks from the Mixteca terrane (Mexico)

    NASA Astrophysics Data System (ADS)

    Böhnel, Harald

    1999-11-01

    Three sites from Cretaceous limestone and Jurassic sandstone in northern Oaxaca, Mexico, were studied paleomagnetically. Thermal demagnetization isolated site-mean remanence directions which differ significantly from the recent geomagnetic field. The paleopole for the Albian-Cenomanian Morelos formation is indistinguishable from the corresponding reference pole for stable North America, indicating tectonic stability of the Mixteca terrane since the Cretaceous. Rock magnetic properties and a positive reversal test for the Bajocian Tecomazuchil sandstone suggest that the remanence could be of primary origin, although no fold test could be applied. The Tecomazuchil paleopole is rotated 10°±5° clockwise and displaced 24°±5° towards the study area, with respect to the reference pole for stable North America. Similar values were found for the Toarcien-Aalenian Rosario Formation, with 35°±6° clockwise rotation and 33°±6° latitudinal translation. These data support a post-Bajocian southward translation of the Mixteca terrane by around 25°, which was completed in mid-Cretaceous time.

  15. Middle Jurassic Oseberg delta, northern North Sea: A sedimentological and sequence stratigraphic interpretation

    SciTech Connect

    Muto, T.; Steel R.J.

    1997-07-01

    The Aalenian Oseberg Formation (0-80 m thick) is an important reservoir unit in the Middle Jurassic Brent Group in the northern North Sea, consisting of multiple sets of sandy Gilbert-type deltas. Small-scale (1.5-10 m) fining-upward units seen in the gamma-ray log correspond with individual delta sets, as independently confirmed by steepening-upward trends seen in the dip log. Within each set, the steep foreset slopes typically show thinly bedded sandstone facies (avalanche grain flows), whereas the lower foreset slopes, toesets, and bottomsets are formed largely by massive sandstone facies (sandy debris flows). On an intermediate scale (up to 40 m), the gamma-ray logs show both fining-upward and coarsening-upward trends through stacked delta sets, and these trends, traceable between wells, are interpreted in terms of decelerating and accelerating rates of relative sea level rise, respectively. The relative abundance of the sandy debris-flow deposits reflects a periodic and significant instability of the delta`s upper foreset slope, probably during times of increased water depth in front of the delta. The normal progradation of individual Gilbert-type sets, however, is likely to have been along a subhorizontal topography during periods of little or no change in water depth. The long-term change to produce the observed vertical stacking of deltaic sets was one of a generally rising relative sea level.

  16. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    PubMed Central

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; Lerch, Harry; Olea, Ricardo A.; Suitt, Stephen E.; Kolker, Allan

    2010-01-01

    Indoor air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM2.5 concentration in 20 homes was 36.0 μg/m3. This is the first time that PM2.5 has been quantified and characterized inside Navajo reservation residents' homes. PMID:20671946

  17. Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

    DOE PAGESBeta

    Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; Lerch, Harry; Olea, Ricardo A.; Suitt, Stephen E.; Kolker, Allan

    2010-01-01

    Indoormore » air pollution has been identified as a major risk factor for acute and chronic respiratory diseases throughout the world. In the sovereign Navajo Nation, an American Indian reservation located in the Four Corners area of the USA, people burn coal in their homes for heat. To explore whether/how indoor coal combustion might contribute to poor respiratory health of residents, this study examined respiratory health data, identified household risk factors such as fuel and stove type and use, analyzed samples of locally used coal, and measured and characterized fine particulate airborne matter inside selected homes. In twenty-five percent of homes surveyed coal was burned in stoves not designed for that fuel, and indoor air quality was frequently found to be of a level to raise concerns. The average winter 24-hour PM 2.5 concentration in 20 homes was 36.0  μ g/ m 3 . This is the first time that PM 2.5 has been quantified and characterized inside Navajo reservation residents' homes.« less

  18. Sedimentary petrology and geochemistry of siliciclastic rocks from the upper Jurassic Tordillo Formation (Neuquén Basin, western Argentina): Implications for provenance and tectonic setting

    NASA Astrophysics Data System (ADS)

    Spalletti, Luis A.; Queralt, Ignasi; Matheos, Sergio D.; Colombo, Ferrán; Maggi, Jorge

    2008-06-01

    The Upper Jurassic Tordillo Formation is exposed along the western edge of the Neuquén Basin (west central Argentina) and consists of fluvial strata deposited under arid/semiarid conditions. The pebble composition of conglomerates, mineralogical composition of sandstones and pelitic rocks, and major- and trace-element geochemistry of sandstones, mudstones, and primary pyroclastic deposits are evaluated to determine the provenance and tectonic setting of the sedimentary basin. Conglomerates and sandstones derived almost exclusively from volcanic sources. The stratigraphic sections to the south show a clast population of conglomerates dominated by silicic volcanic fragments and a predominance of feldspathic litharenites. This framework composition records erosion of Triassic-Jurassic synrift volcaniclastic rocks and basement rocks from the Huincul arch, which was exhumed as a result of Late Jurassic inversion. In the northwestern part of the study area, conglomerates show a large proportion of mafic and acidic volcanic rock fragments, and sandstones are characterised by a high content of mafic volcanic rock fragments and plagioclase. These data suggest that the source of the sandstones and conglomerates was primarily the Andean magmatic arc, located west of the Neuquén Basin. The clay mineral assemblage is interpreted as the result of a complex set of factors, including source rock, climate, transport, and diagenesis. Postdepositional processes produced significant variations in the original compositions, especially the fine-grained deposits. The Tordillo sediments are characterised by moderate SiO 2 contents, variable abundances of K 2O and Na 2O, and a relatively high proportion of ferromagnesian elements. The degree of chemical weathering in the source area, expressed as the chemical index of alteration, is low to moderate. The major element geochemistry and Th/Sc, K/Rb, Co/Th, La/Sc, and Cr/Th values point to a significant input of detrital volcanic material of

  19. Clastic Pipes: Proxies of High Water Tables and Strong Ground Motion, Jurassic Carmel Formation, Southern Utah

    NASA Astrophysics Data System (ADS)

    Wheatley, David; Chan, Marjorie

    2015-04-01

    Multiple soft sediment deformation features from bed-scale to basin-scale are well preserved within the Jurassic Carmel Formation of Southern Utah. Field mapping reveals thousands of small-scale clastic injectite pipes (10 cm to 10 m diameter, up to 20 m tall) in extremely high densities (up to 500+ pipes per 0.075 square kilometers). The pipes weather out in positive relief from the surrounding host strata of massive sandstone (sabkha) and crossbedded sands with minor conglomerate and shale (fluvial) deposits. The host rock shows both brittle and ductile deformation. Reverse, normal, and antithetical faulting is common with increased frequency, including ring faults, surrounding the pipes. The pipes formed from liquefaction and subsequent fluidization induced by strong ground motion. Down-dropped, graben blocks and ring faults surrounding pipes indicate initial sediment volume increase during pipe emplacement followed by sediment volume decrease during dewatering. Complex crosscutting relationships indicate several injection events where some pipe events reached the surface as sand blows. Multiple ash layers provide excellent stratigraphic and temporal constraints for the pipe system with the host strata deposited between 166 and 164 Ma. Common volcanic fragments and rounded volcanic cobbles occur within sandstone and conglomerate beds, and pipes. Isolated volcanic clasts in massive sandstone indicate explosive volcanic events that could have been the exogenic trigger for earthquakes. The distribution of pipes are roughly parallel to the Middle Jurassic paleoshoreline located in marginal environments between the shallow epicontinental Sundance Sea and continental dryland. At the vertical stratigraphic facies change from dominantly fluvial sediments to dominantly massive sabkha sediments, there is a 1-2 m-thick floodplain mudstone that was a likely seal for underlying, overpressurized sediments. The combination of loose porous sediment at a critical depth of water

  20. Total petroleum systems of the Pelagian Province, Tunisia, Libya, Italy, and Malta; the Bou Dabbous, Tertiary and Jurassic-Cretaceous composite

    USGS Publications Warehouse

    Klett, T.R.

    2001-01-01

    Undiscovered conventional oil and gas resources were assessed within total petroleum systems of the Pelagian Province (2048) as part of the U.S. Geological Survey World Petroleum Assessment 2000. The Pelagian Province is located mainly in eastern Tunisia and northwestern Libya. Small portions of the province extend into Malta and offshore Italy. Although several petroleum systems may exist, only two ?composite? total petroleum systems were identified. Each total petroleum system comprises a single assessment unit. These total petroleum systems are called the Bou Dabbous?Tertiary and Jurassic-Cretaceous Composite, named after the source-rock intervals and reservoir-rock ages. The main source rocks include mudstone of the Eocene Bou Dabbous Formation; Cretaceous Bahloul, Lower Fahdene, and M?Cherga Formations; and Jurassic Nara Formation. Known reservoirs are in carbonate rocks and sandstone intervals throughout the Upper Jurassic, Cretaceous, and Tertiary sections. Traps for known accumulations include fault blocks, low-amplitude anticlines, high-amplitude anticlines associated with reverse faults, wrench fault structures, and stratigraphic traps. The estimated means of the undiscovered conventional petroleum volumes in total petroleum systems of the Pelagian Province are as follows: [MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids] Total Petroleum System MMBO BCFG MMBNGL Bou Dabbous?Tertiary 667 2,746 64 Jurassic-Cretaceous Composite 403 2,280 27

  1. Late Paleozoic to Jurassic tectonic evolution of the Bogda area (northwest China): Evidence from detrital zircon U-Pb geochronology

    NASA Astrophysics Data System (ADS)

    Tang, Wenhao; Zhang, Zhicheng; Li, Jianfeng; Li, Ke; Chen, Yan; Guo, Zhaojie

    2014-06-01

    Since the Cenozoic, the Tian Shan is rejuvenated by crustal shortening related to the ongoing India-Asia collision. However, the tectonic process prior to the Cenozoic remains ambiguous, especially in the Bogda area of the eastern Tian Shan. The continuous Late Paleozoic-Mesozoic sequences in the Bogda area record abundant information about the basin-mountain interaction. U-Pb (LA-ICP-MS) dating of detrital zircons from seven sandstone samples from Permian to Jurassic was used to investigate the changes of provenance and basin-mountain interaction in the Bogda area. During the Permian, proximal and synchronous pyroclastic materials were the major source. The Late Paleozoic magmatic belt in the North Tian Shan (NTS) had gradually become one of the main sources by the Late Permian, which implies the uplift and exhumation in the NTS area. This is interpreted in terms of near-source sedimentation in basin developing in a post-orogenic extension setting. The large range of U-Pb ages of detrital zircons observed in the Early-Middle Jurassic sediments encompasses most of the available sources implying a wide drainage pattern developing on a rather flat topography. Re-emergence of the Early Permian peak in the spectrum implies that the Bogda Mountains has existed as a gentle positive relief and began to provide materials to the submountain regions. The southern Junggar Basin extended towards to the south and evolved as a passively subsiding basin from the Middle Triassic to the Middle Jurassic. However, the synchronous pyroclastic (tuff) and the exhumed late Paleozoic detrital materials from the uplifted Bogda Mountains were the major component of the Upper Jurassic sediments. Associated to the conglomerate in the Kalaza Formation, the basin-range evolution entered a compression uplift stage. The basin pattern evolution of the Bogda area is consistent with that of the southern Junggar Basin.

  2. Carbohydrate biofuels II: The need and the potential for rootfuel in the Navajo Nation

    SciTech Connect

    Shultz, E.B.; Jr.; Bragg, W.G.; Whittier, J.

    1995-11-01

    Over 80% of rural Navajos and about two-thirds of all Navajos use scarce woodfuel and low-grade coal for home heating half the year, with coal used mainly as a nighttime adjunct. Serious health problems arise because stoves are old and leak smoke and carbon monoxide. The impacts are gender-biased to women and small children. Respiratory disease is a major cause of Navajo mortality and unusually high admissions to Navajo Indian Health Service hospitals. A 1990 study at a Navajo hospital showed that Navajo children under two years of age from homes with woodstoves are nearly five times more likely to contract acute lower respiratory tract infections than children from homes with no stove. Correctives include improved stoves and fuels. Our previous studies on clean-burning starchy/cellulosic {open_quotes}rootfuels{close_quotes} in Latin America, Africa, and Asia are applicable. We discuss our preliminary work on the Navajo reservation, the current status of household stoves and stovefuels, the health impacts of woodsmoke and coalsmoke from old, faulty stoves, the conditions for growing rootfuel on the reservation, and policy and strategy for coping with the problem.

  3. Delivering pneumococcal vaccine to a high risk population: the Navajo experience.

    PubMed

    Benin, Andrea L; Watt, James P; O'Brien, Katherine L; Reid, Raymond; Zell, Elizabeth R; Katz, Scott; Donaldson, Connie; Schuchat, Anne; Santosham, Mathuram; Whitney, Cynthia G

    2005-01-01

    High rates of preventable diseases such as pneumococcal disease occur among the Navajo despite their universal health insurance through the Indian Health Service. The objective of this study was to determine the proportion of Navajo adults vaccinated with pneumococcal polysaccharide vaccine and to examine key features of vaccination programs of the Navajo Indian Health Service. For this cross-sectional study, medical charts of Navajo patients with vaccine indications were randomly selected and reviewed to determine who had been vaccinated as of January 1, 1999. Among 480 Navajo>or=65 years old, 73% were vaccinated (95% confidence interval [CI]: 69%-77%). Among 111 Navajo 18-64 years old with vaccine indications, 54% were vaccinated (95% CI: 45% -63%). Vaccination programs utilized extensive public health nursing, home visits, standing orders, and "express lane" clinics. In spite of excellent delivery systems and universal healthcare, the proportion of Navajo persons vaccinated was still below the goals for Healthy People 2010 of having 90% of persons>or=65 years old vaccinated and 60% of high-risk persons 18-64 years old vaccinated. PMID:17038821

  4. Uranium mining and lung cancer among Navajo men in New Mexico and Arizona, 1969 to 1993.

    PubMed

    Gilliland, F D; Hunt, W C; Pardilla, M; Key, C R

    2000-03-01

    Navajo men who were underground miners have excess risk of lung cancer. To further characterize the long-term consequences of uranium mining in this high-risk population, we examined lung cancer incidence among Navajo men residing in New Mexico and Arizona from 1969 to 1993 and conducted a population-based case-control study to estimate the risk of lung cancer for Navajo uranium miners. Uranium mining contributed substantially to lung cancer among Navajo men over the 25-year period following the end of mining for the Navajo Nation. Sixty-three (67%) of the 94-incident lung cancers among Navajo men occurred in former uranium miners. The relative risk for a history of mining was 28.6 (95% confidence interval, 13.2-61.7). Smoking did not account for the strong relationship between lung cancer and uranium mining. The Navajo experience with uranium mining is a unique example of exposure in a single occupation accounting for the majority of lung cancers in an entire population. PMID:10738707

  5. Jurassic platform development, northwestern Gulf of Mexico

    SciTech Connect

    Moore, C.H. Jr.

    1987-05-01

    Triassic and Early Jurassic rifting set the stage for the subsequent development of carbonate platforms in the Late Jurassic. These platforms formed along the interior margins of salt basins separated from the main ancestral Gulf of Mexico by a series of positive features. A major sea level rise, after deposition of the Louann Salt (late Callovian), drowned the interior salt basins around the margins of the Gulf of Mexico, leading to an anoxic event. Organic-rich sediments of the lower Smackover were deposited as a basin-fill sequence, forming one of the major hydrocarbon source rocks of the region. As sea level rise slowed in the late Oxfordian, carbonate production began to catch up with sea level rise along the basin margins, leading to the initial development of a rimmed carbonate platform. The platform margin was marked by high-energy ooid grainstones, while crustacean pellet muds were deposited in the platform interior. A high-energy ooid-dominated platform (upper Smackover) developed in the late Oxfordian when sea level reached a standstill. During the subsequent Kimmeridgian sea level rise, a second rimmed carbonate platform, the Haynesville, was developed. During the initial rise, grainstones were deposited on the platform margin, while the interior was dominated by evaporites (Buckner) and siliciclastics. As sea level slowed and reached a standstill, the platform margin facies extended shoreward (Gilmer) and a high-energy platform, analogous to the upper Smackover, was formed. The Smackover and Haynesville platforms of the northwestern gulf show a parallel evolution in response to cyclic changes in Upper Jurassic sea level.

  6. Paleoenvironments and hydrocarbon potential of Upper Jurassic Norphlet Formation of southwestern Alabama and adjacent coastal water area

    SciTech Connect

    Mancini, E.A.; Mink, R.M.; Bearden, B.L.

    1984-09-01

    Upper Jurassic Norphlet sediments in southwestern Alabama and the adjacent coastal water area accumulated under arid climatic conditions. The Appalachian Mountains of the eastern United States extended into southwestern Alabama, providing a barrier for air and water circulation during Norphlet deposition. Norphlet paleogeography was dominated by a broad desert plain rimmed to the north and east by the Appalachians and to the south by a developing shallow sea. Initiation of Norphlet sedimentation was a result of erosion of the southern Appalachians. Norphlet conglomerates were deposited in coalescing alluvial fans in proximity to an Appalachian source. The conglomeratic sandstones grade downdip into red-bed lithofacies that accumulated in distal portions of alluvial fan and wadi systems. Quartzose sandstones (Denkman Member) were deposited as dune and interdune sediments on a broad desert plain. The source of the sand was the updip and adjacent alluvial fan, plain, and wadi deposits. A marine transgression was initiated late in Denkman deposition, resulting in the reworking of previously deposited Norphlet sediments. Norphlet hydrocarbon potential in southwestern and offshore Alabama is excellent with four oil and gas fields already established. Petroleum traps discovered to date are primarily structural traps involving salt anticlines, faulted salt anticlines, and extensional fault traps associated with salt movement. Reservoir rocks consist of quartzose sandstones, which are principally eolian in origin. Smackover algal carbonate mudstones were probably the source for the Norphlet hydrocarbons.

  7. Solar membrane distillation: desalination for the Navajo Nation.

    PubMed

    Karanikola, Vasiliki; Corral, Andrea F; Mette, Patrick; Jiang, Hua; Arnoldand, Robert G; Ela, Wendell P

    2014-01-01

    Provision of clean water is among the most serious, long-term challenges in the world. To an ever increasing degree, sustainable water supply depends on the utilization of water of impaired initial quality. This is particularly true in developing nations and in water-stressed areas such as the American Southwest. One clear example is the Navajo Nation. The reservation covers 27,000 square miles, mainly in northeastern Arizona. Low population density coupled with water scarcity and impairment makes provision of clean water particularly challenging. The Navajos rely primarily on ground water, which is often present in deep aquifers or of brackish quality. Commonly, reverse osmosis (RO) is chosen to desalinate brackish ground water, since RO costs are competitive with those of thermal desalination, even for seawater applications. However, both conventional thermal distillation and RO are energy intensive, complex processes that discourage decentralized or rural implementation. In addition, both technologies demand technical experience for operation and maintenance, and are susceptible to scaling and fouling unless extensive feed pretreatment is employed. Membrane distillation (MD), driven by vapor pressure gradients, can potentially overcome many of these drawbacks. MD can operate using low-grade, sub-boiling sources of heat and does not require extensive operational experience. This presentation discusses a project on the Navajo Nation, Arizona (Native American tribal lands) that is designed to investigate and deploy an autonomous (off-grid) system to pump and treat brackish groundwater using solar energy. Βench-scale, hollow fiber MD experiment results showed permeate water fluxes from 21 L/m2·d can be achieved with transmembrane temperature differences between 40 and 80˚C. Tests run with various feed salt concentrations indicate that the permeate flux decreases only about 25% as the concentration increases from 0 to 14% (w/w), which is four times seawater salt

  8. Jurassic climate mode governed by ocean gateway

    PubMed Central

    Korte, Christoph; Hesselbo, Stephen P.; Ullmann, Clemens V.; Dietl, Gerd; Ruhl, Micha; Schweigert, Günter; Thibault, Nicolas

    2015-01-01

    The Jurassic (∼201–145 Myr ago) was long considered a warm ‘greenhouse' period; more recently cool, even ‘icehouse' episodes have been postulated. However, the mechanisms governing transition between so-called Warm Modes and Cool Modes are poorly known. Here we present a new large high-quality oxygen-isotope dataset from an interval that includes previously suggested mode transitions. Our results show an especially abrupt earliest Middle Jurassic (∼174 Ma) mid-latitude cooling of seawater by as much as 10 °C in the north–south Laurasian Seaway, a marine passage that connected the equatorial Tethys Ocean to the Boreal Sea. Coincidence in timing with large-scale regional lithospheric updoming of the North Sea region is striking, and we hypothesize that northward oceanic heat transport was impeded by uplift, triggering Cool Mode conditions more widely. This extreme climate-mode transition provides a counter-example to other Mesozoic transitions linked to quantitative change in atmospheric greenhouse gas content. PMID:26658694

  9. Jurassic climate mode governed by ocean gateway.

    PubMed

    Korte, Christoph; Hesselbo, Stephen P; Ullmann, Clemens V; Dietl, Gerd; Ruhl, Micha; Schweigert, Günter; Thibault, Nicolas

    2015-01-01

    The Jurassic (∼201-145 Myr ago) was long considered a warm 'greenhouse' period; more recently cool, even 'icehouse' episodes have been postulated. However, the mechanisms governing transition between so-called Warm Modes and Cool Modes are poorly known. Here we present a new large high-quality oxygen-isotope dataset from an interval that includes previously suggested mode transitions. Our results show an especially abrupt earliest Middle Jurassic (∼174 Ma) mid-latitude cooling of seawater by as much as 10 °C in the north-south Laurasian Seaway, a marine passage that connected the equatorial Tethys Ocean to the Boreal Sea. Coincidence in timing with large-scale regional lithospheric updoming of the North Sea region is striking, and we hypothesize that northward oceanic heat transport was impeded by uplift, triggering Cool Mode conditions more widely. This extreme climate-mode transition provides a counter-example to other Mesozoic transitions linked to quantitative change in atmospheric greenhouse gas content. PMID:26658694

  10. Jurassic climate mode governed by ocean gateway

    NASA Astrophysics Data System (ADS)

    Korte, Christoph; Hesselbo, Stephen P.; Ullmann, Clemens V.; Dietl, Gerd; Ruhl, Micha; Schweigert, Günter; Thibault, Nicolas

    2015-12-01

    The Jurassic (~201-145 Myr ago) was long considered a warm `greenhouse' period; more recently cool, even `icehouse' episodes have been postulated. However, the mechanisms governing transition between so-called Warm Modes and Cool Modes are poorly known. Here we present a new large high-quality oxygen-isotope dataset from an interval that includes previously suggested mode transitions. Our results show an especially abrupt earliest Middle Jurassic (~174 Ma) mid-latitude cooling of seawater by as much as 10 °C in the north-south Laurasian Seaway, a marine passage that connected the equatorial Tethys Ocean to the Boreal Sea. Coincidence in timing with large-scale regional lithospheric updoming of the North Sea region is striking, and we hypothesize that northward oceanic heat transport was impeded by uplift, triggering Cool Mode conditions more widely. This extreme climate-mode transition provides a counter-example to other Mesozoic transitions linked to quantitative change in atmospheric greenhouse gas content.

  11. Remote detection of fluid-related diagenetic mineralogical variations in the Wingate Sandstone at different spatial and spectral resolutions

    NASA Astrophysics Data System (ADS)

    Okyay, Unal; Khan, Shuhab D.

    2016-02-01

    Well-exposed eolian units of the Jurassic system on the Colorado Plateau including the Wingate Sandstone, show prominent color variations throughout southeastern Utah due to diagenetic changes that include precipitation and/or removal of iron oxide, clay, and carbonate cement. Spatially variable characteristic diagenetic changes suggest fluid-rock interactions through the sandstone. Distinctive spectral signatures of diagenetic minerals can be used to map diagenetic mineral variability and possibly fluid-flow pathways. The main objective of this work was to identify characteristic diagenetic minerals, and map their spatial variability from regional to outcrop scale in Wingate Sandstone exposures of Lisbon Valley, Utah. Laboratory reflectance spectroscopy analysis of the samples facilitated identification of diagnostic spectral characteristics of the common diagenetic minerals and their relative abundances between altered and unaltered Wingate Sandstone. Comparison of reflectance spectroscopy with satellite, airborne, and ground-based imaging spectroscopy data provided a method for mapping and evaluating spatial variations of diagenetic minerals. The Feature-oriented Principal Component Selection method was used on Advanced Spaceborne Thermal Emission and Reflection Radiometer data so as to map common mineral groups throughout the broader Wingate Sandstone exposure in the area. The Minimum Noise Fraction and Spectral Angle Mapper methods were applied on airborne HyMap and ground-based hyperspectral imaging data to identify and map mineralogical changes. The satellite and airborne data showed that out of 25.55 km2 total exposure of Wingate Sandstone in Lisbon Valley, unaltered sandstone cover 12.55 km2, and altered sandstone cover 8.90 km2 in the northwest flank and 5.09 km2 in the southern flank of the anticline. The ground-based hyperspectral data demonstrated the ability to identify and map mineral assemblages with two-dimensional lateral continuity on near

  12. Breast cancer education for Navajo women: a pilot study evaluating a culturally relevant video.

    PubMed

    Sanderson, Priscilla R; Teufel-Shone, Nicolette I; Baldwin, Julie A; Sandoval, Nellie; Robinson, Frances

    2010-06-01

    This pilot study evaluated a culturally specific video designed to teach Navajo women about breast cancer treatment options. Fourteen Navajo women diagnosed with breast cancer and 26 healthcare providers participated in a mixed-method evaluation that documented their perceptions immediately and 6 months after viewing the video. After initial viewing, women reported reduced anxiety about treatment and interest in support groups. Six months later, women said the video prompted them to seek more information from printed sources and their provider. Younger Navajo women who were 44 to 51 years old were more likely to attend support groups than women who were 55-67 years. Providers corroborated the positive effects of the video. The providers believed the video encouraged patients to seek information about breast cancer and to ask questions about treatment plans and side effects. A culturally relevant video for Navajo women can be an effective teaching tool and can enhance patient-provider communication. PMID:20111913

  13. Geologic map of the Winslow 30’ × 60’ quadrangle, Coconino and Navajo Counties, northern Arizona

    USGS Publications Warehouse

    Billingsley, George H.; Block, Debra; Redsteer, Margaret Hiza

    2013-01-01

    The Winslow 30’ × 60’ quadrangle encompasses approximately 5,018 km2 (1,960 mi2) within Coconino and Navajo Counties of northern Arizona. It is characterized by gently dipping Paleozoic and Mesozoic strata that dip 1° to 2° northeastward in the southwestern part of the quadrangle and become nearly flat-lying in the northeastern part of the quadrangle. In the northeastern part, a shallow Cenozoic erosional basin developed about 20 million years ago, which subsequently was filled with flat-lying Miocene and Pliocene lacustrine sediments of the Bidahochi Formation, as well as associated volcanic rocks of the Hopi Buttes Volcanic Field. The lacustrine sediments and volcanic rocks unconformably overlie Triassic, Jurassic, and Cretaceous strata. Beginning about early Pliocene time, the Little Colorado River and its tributaries began to remove large volumes of Paleozoic and Mesozoic bedrock from the map area. This erosional development has continued through Pleistocene and Holocene time. Fluvial sediments accumulated episodically throughout this erosional cycle, as indicated by isolated Pliocene(?) and Pleistocene Little Colorado River terrace-gravel deposits on Tucker Mesa and Toltec Divide west of Winslow and younger terrace-gravel deposits along the margins of the Little Colorado River Valley. These gravel deposits suggest that the ancestral Little Colorado River and its valley has eroded and migrated northeastward toward its present location and largely parallels the strike of the Chinle Formation. Today, the Little Colorado River meanders within a 5-km (3-mi) wide valley between Winslow and Leupp, where soft strata of the Chinle Formation is mostly covered by an unknown thickness of Holocene flood-plain deposits. In modern times, the Little Colorado River channel has changed its position as much as a 1.5 km (1 mi) during flood events, but for much of the year the channel is a dry river bed. Surficial alluvial and eolian deposits cover extensive parts of the

  14. Age spectra of detrital zircon of the Jurassic clastic rocks of the Mino-Tanba AC belt in SW Japan: Constraints to the provenance of the mid-Mesozoic trench in East Asia

    NASA Astrophysics Data System (ADS)

    Fujisaki, Wataru; Isozaki, Yukio; Maki, Kenshi; Sakata, Shuhei; Hirata, Takafumi; Maruyama, Shigenori

    2014-07-01

    U-Pb ages of detrital zircon grains were determined from an upper Middle Jurassic siliceous mudstone and two lower Upper Jurassic sandstones of the Mino-Tanba belt, Southwest Japan, by Laser-ablation ICPMS. The age spectra of detrital zircon grains of the three analyzed samples show multiple age clusters: 175-198 Ma (Early Jurassic), 202-284 Ma (Permian to Triassic), 336-431 Ma (Silurian to Carboniferous), and 1691-2657 Ma (Neoarchean to Paleoproterozoic). As per the Precambrian grains, the prominent peak exists around 1800-2000 Ma in all analyzed samples. The age clusters of 175-198 Ma, 202-284 Ma, and 336-431 Ma suggest that pre-Middle Jurassic Japan has exposed older granitic batholiths. The corresponding batholiths occur in the Cathaysian part of South China block. In contrast, the absence of them in modern Japan suggests that these batholiths were totally consumed by post-Jurassic tectonic erosion. The Neoarchean to Paleoproterozoic detrital zircon grains were derived from South China, North China, or possibly both of them; nonetheless, the circumstantial geologic lines of evidence point to South China, in particular to Cathaysia, rather than North China.

  15. A review of Yellow Dirt: A Poisoned Land and the Betrayal of the Navajos.

    PubMed

    Adams, Nicole

    2015-05-01

    Yellow Dirt is a thorough account of the past and present state of the Navajo Nation with regards to uranium mining. Through a journalistic approach Judy Pasternak weaves the story of the betrayal of the Navajo people. This book highlights the impact of environment on health and this review calls all nurses to be aware of these impacts and incorporate this type of knowledge into their practice. PMID:25172455

  16. Healthy Gardens/Healthy Lives: Navajo perceptions of growing food locally to prevent diabetes and cancer

    PubMed Central

    Beresford, Shirley A.A.; Ornelas, India; Topaha, Carmelita; Becenti, Tonia; Thomas, Dustin; Vela, Jaime G.

    2013-01-01

    Poor access to nutritious foods, departure from traditional diets, and reduced physical activity are associated with a rise in type-2 diabetes and certain types of cancers among the Navajo. Diabetes in particular is of concern because of its increased prevalence among Navajo youth. Gardening can successfully address issues of poor availability of fruits and vegetables and offer many other social and health benefits. Our assessment aimed to determine Navajo attitudes about gardening and health in San Juan County, New Mexico. We conducted seven focus groups (including 31 people) to assess knowledge and attitudes related to gardening, and uncover barriers and facilitators to participation in a garden project. Each group session was moderated by two Navajo students. Transcripts revealed that many Navajo are aware of adverse health issues, predominantly obesity and diabetes, which occur on the reservation. Participants expressed a preference for educational approaches that incorporated cultural traditions, respect for elders, use of visual aids and experiential learning. Several social and agronomic barriers to gardening were also mentioned. Results suggested a broad interest in promoting gardening especially to reduce the risk of diabetes with the added value of enhancing social capital in Navajo communities. PMID:23855020

  17. Navajo Generating Station and Clean-Energy Alternatives: Options for Renewables

    SciTech Connect

    Hurlbut, D. J.; Haase, S.; Turchi, C. S.; Burman, K.

    2012-06-01

    In January 2012, the National Renewable Energy Laboratory delivered to the Department of the Interior the first part of a study on Navajo Generating Station (Navajo GS) and the likely impacts of BART compliance options. That document establishes a comprehensive baseline for the analysis of clean energy alternatives, and their ability to achieve benefits similar to those that Navajo GS currently provides. This analysis is a supplement to NREL's January 2012 study. It provides a high level examination of several clean energy alternatives, based on the previous analysis. Each has particular characteristics affecting its relevance as an alternative to Navajo GS. It is assumed that the development of any alternative resource (or portfolio of resources) to replace all or a portion of Navajo GS would occur at the end of a staged transition plan designed to reduce economic disruption. We assume that replacing the federal government's 24.3% share of Navajo GS would be a cooperative responsibility of both the U.S. Bureau of Reclamation (USBR) and the Central Arizona Water Conservation District (CAWCD).

  18. "The lizard in the green bottle": "aging out" of problem drinking among Navajo men.

    PubMed

    Quintero, G

    2000-10-01

    The Navajo exhibit a number of indicators suggesting the extent of significant problems associated with drinking and alcohol abuse. Measures of alcohol-related mortality and morbidity provide stark testimony regarding the shape and magnitude of problem drinking among the Navajo. While these measures highlight patterns of drinking that often result in social, physical, and psychological pathology, there are other, less noted patterns of Navajo drinking. This paper describes a salient, if often overlooked, pattern of Native American drinking by examining the aging out phenomenon among Navajo men. Using narratives collected from former problem drinkers, this paper describes the factors and motivations associated with this sometimes dramatic change in drinking behavior. Several themes emerge from these narratives that help explain the aging out process. These themes include health concerns, religious involvement, living a traditional Navajo way of life, and the responsibilities and life changes associated with child rearing. This paper not only provides detail on a category of drinker and drinking phenomena that is largely ignored in accounts of Native American drinking, but also illustrates some of the values and meanings attached to drinking cessation and highlights the relation between changes in drinking behavior and stages in life course among Navajo men. PMID:11005391

  19. Healthy gardens/healthy lives: Navajo perceptions of growing food locally to prevent diabetes and cancer.

    PubMed

    Lombard, Kevin A; Beresford, Shirley A A; Ornelas, India J; Topaha, Carmelita; Becenti, Tonia; Thomas, Dustin; Vela, Jaime G

    2014-03-01

    Poor access to nutritious foods, departure from traditional diets, and reduced physical activity are associated with a rise in type 2 diabetes and certain types of cancers among the Navajo. Diabetes in particular is of concern because of its increased prevalence among Navajo youth. Gardening can successfully address issues of poor availability of fruits and vegetables and offer many other social and health benefits. Our assessment aimed to determine Navajo attitudes about gardening and health in San Juan County, New Mexico. We conducted seven focus groups (including 31 people) to assess knowledge and attitudes related to gardening and uncover barriers and facilitators to participation in a garden project. Each group session was moderated by two Navajo students. Transcripts revealed that many Navajo are aware of adverse health issues that occur on the reservation, predominantly obesity and diabetes. Participants expressed a preference for educational approaches that incorporated cultural traditions, respect for elders, use of visual aids, and experiential learning. Several social and agronomic barriers to gardening were also mentioned. Results suggested a broad interest in promoting gardening especially to reduce the risk of diabetes with the added value of enhancing social capital in Navajo communities. PMID:23855020

  20. Volcanic Facies of the Lower Jurassic Talkeetna Formation, Iniskin Peninsula to Tuxedni Bay, Alaska Peninsula

    NASA Astrophysics Data System (ADS)

    Bull, K. F.

    2015-12-01

    The Lower Jurassic Talkeetna Formation (Jtk), a >1,000-km-long belt of vol­canic facies within the accreted intra-oceanic Talkeetna Arc has been characterized within the Talkeetna Mountains, but on the Alaska Peninsula Jtk facies have not previously been described in detail. Here we describe facies of the Jtk stretching from the Iniskin Peninsula to Tuxedni Bay. On the Iniskin Peninsula, a high concentration and great thickness of mafic to intermediate lavas, associated autobreccias and hyaloclastites, fluidal-clast breccias and possible pillows are suggestive of one or more submarine effusive eruption centers. Also volumetrically significant are non-stratified polymictic volcaniclastic breccia facies. Minor facies include thinly bedded volcaniclastic sandstone to pebble breccia-conglomerate facies, some of which are shard- and pumice-bearing pyroclastic deposits preserved in thinly bedded deposits, indicative of episodes of explosive volcanism and the eruption-fed nature of some of the deposits. North of Chinitna Bay, coherent facies tend to be thin and relatively small in volume. Volcaniclastic facies provide evidence of subaerial-fluvial deposition, and pyroclastic activity. Thinly bedded, laterally continuous beds locally exhibit cross-laminations, channel fills, normal grading and lenticular beds, and contain plant fossils. Within this sequence is a 10-m-thick pumice breccia containing fossilized logs, underlain by a thin, weakly laminated, pumice- and lithic-bearing volcaniclastic siltstone to sandstone. The log-bearing pumice breccia and the lithic-bearing laminated basal unit represent pyroclastic density current (PDC) facies deposited in a subaerial or possibly shallow aqueous environment. Underlying the PDC deposit are several 30-cm-thick maroon and olive green volcaniclastic fine-grained sandstone and siltstone beds containing channel fills, cross-beds and lenticular beds. Marbles exposed in the contact zone between the intrusions of Alaska

  1. Paleomagnetism of Jurassic dolerites from Northern Victoria Land, Antarctica - Onset of rapid Jurassic pole shift?

    NASA Astrophysics Data System (ADS)

    Kirscher, U.; Bachtadse, V.; Petersen, N.; Rolf, C.; Lemna, O. S.

    2014-12-01

    Flood basalts (Kirkpatrick) and sills (Ferrar) of the Transantarctic mountains (183Ma) have been studied paleomagnetically in detail in the 60's to 90's of the 1900's yielding two groups of paleopole positions plotting at ~55°S (A) or at ~80°S (B). Group A poles have been interpreted to reflect the Early Jurassic Earth magnetic field but the significance of Group B poles is less clear. Here we report new data from the Kirkpatrick basalts at Gair Mesa (73.47°S; 162.87°E), where about 800 stratigraphic meters including 23 volcanic flows were sampled. After removal of a steep magnetic overprint straight linear segments trending toward the origin of the projection plane are identified in 151 samples from 22 sites. All characteristic directions are of normal polarity and interpreted to be carried by magnetite. The resulting mean pole plots at 66.4°S; 227.7°E, A95=6.2°, k = 25.7 similar to group B poles. Reflecting light microscopy suggests that the original magnetization has survived low temperature alteration. Since secular variation has been averaged (Sb=15.9°) we argue that the Gair Mesa basalts have recorded the time averaged geomagnetic field during early to mid Jurassic times. Hence, we conclude that both groups A and B are of primary origin and consequently speculate that group B paleopoles might reflect the onset of the recently postulated Jurassic pole shift.

  2. Provenance and tectonic-paleogeographic evolution: Constraints from detrital zircon U-Pb ages of Late Triassic-Early Jurassic deposits in the northern Sichuan basin, central China

    NASA Astrophysics Data System (ADS)

    Shao, Tongbin; Cheng, Nanfei; Song, Maoshuang

    2016-09-01

    U-Pb ages of 290 new detrital zircons from five Late Triassic-Early Jurassic sandstone samples in the northern Sichuan basin, along with other geological data, are used to constrain the sediment provenance and evaluate tectonic-paleogeographic evolution for the adjacent orogens through/from which these sediments were potentially derived. The Upper Triassic depocenter was located at the front of the Longmen Shan belt, and sediments in the western, southern and eastern Sichuan basin shared the southern North China block (NCB) and Qinling belt with the eastern Songpan-Ganzi terrane of Middle-Upper Triassic via the Longmen Shan belt, whereas the northern part of the basin was fed by dominant South Qinling belt (SQB) and northern Yangtze block and possibly subordinate southern NCB. Also, the youngest population in the northern Sichuan basin has a slightly younger age peak (∼235 Ma) than those (∼270 Ma) in other parts of the basin. During the Early Jurassic, the depocenter was still at the front of the Longmen Shan belt but only northern regions (e.g., SQB and northern Yangtze block) fed the basin. The northern Sichuan basin received less sediments from the southern NCB and more from the SQB and northern Yangtze block during the Early Jurassic than during the Late Triassic. The middle Mesoproterozoic detrital zircons, which likely originated from the North Qinling belt and northern Yangtze block where rocks with these zircons may be unexposed, occur more widely in the Lower Jurassic than in the Upper Triassic. These facts suggest that from the Late Triassic to Early Jurassic, it was increasingly difficult for sediments to transport from the NCB into the northern Sichuan basin and the provenance transferred progressively from the southern NCB to both the SQB and northern Yangtze block, implying the continuous South China block-NCB collision during that time.

  3. Lithological and Petrographic Analyses of Carbonates and Sandstones From the Southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Garcia-Avendaño, A.; Urrutia-Fucugauchi, J.

    2012-04-01

    We present results of sedimentological and petrological studies of drill cores from the Bay of Campeche in the southern Gulf of Mexico. Based on reports on drill cores obtained from oil exploratory wells in the Cantarell Complex located 80 kilometres offshore in the Bay of Campeche and studies related to regional geology composite simplified stratigraphic columns for offshore Campeche region have been constructed up to depths of approximately 5000 m. The stratigraphic column is formed by a thick sediment sequence of Middle Jurassic age (evaporites, Callovian), Late Jurassic (terrigenous, calcareous clays and calcareous layers), Lower Cretaceous (carbonates), Upper Cretaceous-Paleogene (calcareous breccias), Paleogene-Neogene (terrigenous-carbonates intercalations) and Quaternary (terrigenous). The core samples studied come from wells in the Sihil and Akal fields in Cantarell. Analysis of reports on lithological descriptions indicates that these wells sample dolomitized sedimentary breccias from the Upper Cretaceous-Paleocene and fine-grained sandstones from the Late Jurassic Tithonian, respectively. Based on results of petrographic studies, the texture, cementing material and porosity of the units have been documented. The thin sections for carbonates were classified based on their texture according to Dunham (1962) for carbonate rocks, classified according to their components using the ternary diagrams of Folk (1974). Percentages refer to the data presented in tables, which were obtained by point-counting technique (with a total 250). Photomicrographs of scanning electron microscope (SEM) provide magnification for easy documentation of crystalline arrangements and description of micro-porous for different types of carbonates such as dolomite, in addition to the morphology of authigenic clays. Results of these studies and previous works in the area permit characterization of diagenetic processes of the carbonate sediments in the Campeche Bay, and provide

  4. "Sydney sandstone": Heritage Stone from Australia

    NASA Astrophysics Data System (ADS)

    Cooper, Barry; Kramar, Sabina

    2014-05-01

    Sydney is Australia's oldest city being founded in 1788. The city was fortunate to be established on an extensive and a relatively undeformed layer of lithified quartz sandstone of Triassic age that has proved to be an ideal building stone. The stone has been long identified by geologists as the Hawkesbury Sandstone. On the other hand the term "Sydney sandstone" has also been widely used over a long period, even to the extent of being utilised as the title of published books, so its formal designation as a heritage stone will immediately formalise this term. The oldest international usage is believed to be its use in the construction of the Stone Store at Kerikeri, New Zealand (1832-1836). In the late 19th century, public buildings such as hospitals, court houses as well as the prominent Sydney Town Hall, Sydney General Post Office, Art Gallery of New South Wales, State Library of New South Wales as well as numerous schools, churches, office building buildings, University, hotels, houses, retaining walls were all constructed using Sydney sandstone. Innumerable sculptures utilising the gold-coloured stone also embellished the city ranging from decorative friezes and capitals on building to significant monuments. Also in the late 19th and early 20th century, Sydney sandstone was used for major construction in most other major Australian cities especially Melbourne, Adelaide and Brisbane to the extent that complaints were expressed that suitable local stone materials were being neglected. Quarrying of Sydney sandstone continues today. In 2000 it was recorded noted that there were 33 significant operating Sydney sandstone quarries including aggregate and dimension stone operations. In addition sandstone continues to be sourced today from construction sites across the city area. Today major dimension stone producers (eg Gosford Quarries) sell Sydney sandstone not only into the Sydney market but also on national and international markets as cladding and paving products

  5. Microstructure of deformed graywacke sandstones

    SciTech Connect

    Dengler, L.A.

    1980-03-05

    Microsctures in low-permeability graywacke sandstones were studied by optical and scanning electron microscopy (SEM). SEM specimens were prepared by ion-bombardment of thick polished samples. The undeformed rock contains grains in a matrix composed primarily of authigenic chlorite and kaolinite. Chlorite platelets are randomly arranged in face-to-edge relation to one another. Kaolinite occurs as pseudohexagonal crystals stacked face-to-face in pore filling books. Uniaxial-stress experiments covered a range of confining pressures from .1 to 600 MPa. Below 50 MPa confining pressure, intergranular fracturing occurs within the fault zone and near the sample's cylindrical surface. Between 100 and 300 MPa confining pressure, fault zones contain highly fractured grains, gauge and slickensides on grain surfaces. At 600 MPa, the sample contains a diffuse shear zone of highly fractured grains and no well-defined fault. In all samples, the distribution of microcracks is heterogeneous. Different clay minerals exhibit different modes of deformation. Chlorite structure responds to applied stress by compaction, reducing both pore size and volume. Chlorite platelets are plastically deformed in even the least strained samples. Kaolinite does not deform plastically in any of the samples examined. Deformation of kaolinite is restricted to toppling of the book structure. Dilatant crack growth was studied in two samples unloaded prior to failure. Uniaxially-strained samples deform primarily along grain boundaries, producing intergranular cracks and realignment of chlorite platelets. Intragranular crack density is linearly related to axial-strain, although grains are less fractured than in uniaxially-stressed samples tested at equivalent mean pressures. Cracks are rarely longer than a grain diameter. Nuclear-explosively deformed samples were recovered after the Rio Blanco gas stimulation experiment. (JGB)

  6. Sedimentary evolution and palaeogeography of mid-Jurassic deposits of the Central High Atlas, Morocco

    NASA Astrophysics Data System (ADS)

    Ait Addi, Abdellah; Chafiki, Driss

    2013-08-01

    In the axis of the Moroccan Central High Atlas rift basin, Toarcian-Middle Jurassic deposits, excepting the early Toarcian Tagoudite Formation, are represented by two formations - Agoudim and Tazigzaout - comprising clays, marls and limestones. On the margins of the basin, the lateral equivalents of these two formations are dolostone-dominated and show the lithological and environmental characteristics of the Bin El Ouidane Group recognized in the NW part of the Central High Atlas (Beni-Mellal/Azilal area). This group is overlain by clays and limestones of the Tillouguite Formation and by Bathonian red beds (silts, sandstones and conglomerates) of the Anemzi Formation. From the Toarcian to Aalenian (Agoudim Members I and II) the contrasting palaeogeographical evolution is marked by a relatively deep central basin bordered by shallow marine carbonates. The Aalenian-Lower Bajocian interval (Agoudim Member II) contains lenticular biodetritic limestones within hemipelagic deposits. These facies resulted from recurrent faulting (tectonic pulses), which was at the origin of the individualization of a series of ridges and depocentres within the High Atlas trough. During the Bajocian (Agoudim Members III and IV) the palaeogeography became homogeneous across the Central High Atlas and corresponded to a carbonate ramp with coral patch reefs. During the ?Late Bajocian (Tazigzaout Lower Member) a new palaeogeography developed with reappearance of the central depocentres. During the latest Bajocian-earliest Bathonian (Tazigzaout Upper Member) a very homogeneous carbonate ramp was again established. These times of uniform palaeogeography are interpreted as relative stable tectonic periods that were progressive stages leading to the ending of the Toarcian-Middle Jurassic sedimentary cycles in the Central High Atlas rift basin of Morocco.

  7. Paleomagnetic evidence for Post-Jurassic stability of southeastern Mexico: Maya Terrane

    NASA Astrophysics Data System (ADS)

    Guerrero, Jose C.; Herrero-Bervera, Emilio; Helsley, Charles E.

    1990-05-01

    The tectonic evolution of southeastern Mexico has been a subject of major controversy, not only in regard to past geometry but also in the timing of proposed geological events as well. For the past 10 years, most, if not all, investigators agree that the Gulf of Mexico Basin was formed by Late Jurassic time and that the Maya Terrane was in its current location prior to the Cretaceous. In order to gain further insight into the drift history of the Maya Terrane we have undertaken a paleomagnetic study of the uppermost Jurassic-Lower Cretaceous (Tithonian-lower Neocomian?) San Ricardo Formation in southeastern Mexico, at 93.7°W, 16.8°N. The sampling site is located east of the Isthmus of Tehuantepec, on the southwest side of the Maya block, at the base of the Yucatan Peninsula. A suite of 133 samples was collected in stratigraphic succession from a 114-m-thick sequence of red shales and sandstones near Cintalapa, Chiapas, Mexico. After progressive thermal demagnetization of all samples at six steps from 350°C to 630°C, 89 samples were selected for final paleopole analysis on the basis of their magnetic stability. Four different polarity intervals were observed, the sequence being from bottom to top: N, R, N, R which assists in the assessment of the reliability of the observations. The mean pole position obtained, 160.0°E, 69.8°N, agrees with the mean pole position of the upper part of the Morrison Formation of Colorado, a unit of virtually identical age. These results indicate that no discernible rotation or displacement of the Maya block has occurred since at least early Neocomian times.

  8. Vertebrate fossils and trace fossils in Upper Jurassic-Lower cretaceous red beds in the Atacama region, Chile

    NASA Astrophysics Data System (ADS)

    Bell, C. M.; Suárez, M.

    Pterosaur, dinosaur, and crocodile bones are recorded here for the first time in Upper Jurassic-Lower Cretaceous red beds in the Atacama region east of Copiapó, Chile. Trace fossils produced by vertebrate animals include the footprints of theropod dinosaurs and the depressions of sandstone laminae interpreted as burrows and foot impressions. The fossils occur in the 1500-meter-thick Quebrada Monardes Formation, which consists predominantly of the aeolian and alluvial deposits of a semi-arid terrestrial environment. Vertebrate fossils are very rare in Chile. Dinosaur bones and footprints have previously been recorded at only seven locations, and pterosaur remains at only one location. The newly discovered dinosaur bones are the oldest to be described in Chile.

  9. Cross-bedding Related Anisotropy and its Role in the Orientation of Joints in an Aeolian Sandstone

    NASA Astrophysics Data System (ADS)

    Deng, S.; Cilona, A.; Mapeli, C.; Panfilau, A.; Aydin, A.; Prasad, M.

    2014-12-01

    Previous research revealed that the cross-bedding related anisotropy in aeolian sandstones affects the orientation of compaction bands, also known as anticracks. We hypothesize that cross-bedding should a have similar influence on the orientation of the joints within the same rock at the same location. To test this hypothesis, we investigated the relationship between the cross-beds and the cross-bed package confined joints in the Jurassic aeolian Aztec Sandstone cropping out in the Valley of Fire State Park, Nevada. The field data demonstrates that the cross-bed package confined joints occur at high-angle to bedding and trend roughly parallel to the dip direction of the cross-beds. This shows that the cross-bed orientation and the associated anisotropy also exert a strong control on the formation and orientation of the joints. In order to characterize the anisotropy due to cross-bedding in the Aztec Sandstone, we measured the P-wave velocities parallel and perpendicular to bedding from 11 samples in the laboratory using a bench-top ultrasonic assembly. The measured P-wave anisotropy is about 13% on average. Based on these results, a numerical model based on the generalized Hooke's law for anisotropic materials is analyzed assuming the cross-bedded sandstone to be transversely isotropic. Using this model, we tested various cross-bed orientations as well as different strain boundary conditions (uniaxial, axisymmetric and triaxial). It is possible to define a boundary condition under which the modeled results roughly match with the observed relationship between cross-bed package confined joints and cross-beds. These results have important implications for fluid flow through aeolian sandstones in reservoirs and aquifers.

  10. Exhumed hydrocarbon traps in East Greenland: Analogs for the lower-middle Jurassic play of northwest Europe

    SciTech Connect

    Price, S.P.; Whitham, A.G.

    1997-02-01

    Four exhumed hydrocarbon traps crop out in the Traill 0 region of East Greenland, each at the footwall crest of a fault-block formed during Early Cretaceous rifting. Former oil accumulations are indicated by a pore fill or pore lining of solid bitumen within the Jurassic sandstone-dominated Vardekloft and Olympen formations. The Vardekloft Formation is divided into an undated fluvial-dominated lower unit (0-520 m) and a Bajocian-Callovian upper unit (65-1020 m) deposited in a shallow-marine environment. The Oxfordian Olympen Formation (0-250 m) contains shallow-marine and fluviodeltaic deposits. The sandstones are dominantly quartzarenites, and petrographic fabrics, such as dissolved feldspar, late quartz cement, and stylolites, are consistent with burial depths in excess of 2.5 km. Porosities ranged from 7 to 27% (generally about 20%, about one-half of which was primary), and permeabilities ranged from 1 to 622 md, prior to the formation of solid bitumen. The distribution of solid bitumen in each trap can be mapped out, allowing sealing elements and original oil-water contacts to be defined. Three of the four exhumed traps (Mols Bjerge, Laplace Bjerg, and Bjornedal) were simple one-seal structural traps. Conformable Upper Jurassic mudstone, unconformable Albian-Cenomanian mudstone, and normal faults are the three top-sealing elements. The fourth (Svinhufvuds Bjerge) was a poly-seal trap with a combined top-seal and a low-side fault closure. Preliminary estimates of the volume of original oil in place within these structures range from 0.2-1.1 billion bbl for the Mols Bjerge trap to 5.3-11.9 billion bbl for the Bjornedal trap. These estimates are prone to large errors, due to uncertainties in estimating original trap geometry, hydrocarbon saturation, and net/gross ratio, and in the understanding of volume changes of hydrocarbon in each trap during thermal degradation of the oil.

  11. Mixed fluvial systems of the Messak Sandstone, a deposit of the Nubian lithofacies, southwestern Libya

    NASA Astrophysics Data System (ADS)

    Lorenz, John C.

    1987-11-01

    The Messak Sandstone is a coarse-grained to pebbly, tabular-crossbedded deposit of the widespread nubian lithofacies. It was deposited during Late Jurassic and/or Early Cretaceous time at the northern edge of the Murzuq basin, in southwestern Libya. Although the sedimentary record is predominantly one of braided fluvial systems, a common subfacies within the formation is interpreted to record the passage of straight-crested sand waves across laterally migrating point bars in sinuous rivers, similar to parts of the modern Ganga and Yamuna rivers. Because the sand waves were larger on the lower parts of the point bar, lateral migration created diagnostic thinning-upward cosets of tabular crossbeds, as well as fining-upward grain-size trends. Common thick, interbedded claystones, deposited in associated paludal and lacustrine environments, and high variance in crossbed dispersion patterns, also suggest the local presence of sinuous fluvial systems within the overall braided regime. The Messak Sandstone contains some of the features that led to the proposal of an unconventional low-sinuosity fluvial environment for the Nubian lithofacies in Egypt, and the continuously high water levels of this model may explain channel-scale clay drapes and overturned crossbeds in the Messak. However, most of the Messak characteristics are incompatible with a low-sinuosity model, suggesting instead that the fluvial channels in the Murzuq basin alternated between braided and high-sinuosity channel patterns.

  12. Mechanism of formation of wiggly compaction bands in porous sandstone: 1. Observations and conceptual model

    NASA Astrophysics Data System (ADS)

    Liu, Chun; Pollard, David D.; Deng, Shang; Aydin, Atilla

    2015-12-01

    Field observations are combined with microscopic analyses to investigate the mechanism of formation of wiggly compaction bands (CBs) in the porous Jurassic aeolian Aztec Sandstone exposed at Valley of Fire State Park, Nevada. Among the three types of CBs (T1, T2, and T3), we focused on the wiggly CBs (T3), which show a chevron (T31) or wavy (T32) pattern with typical corner angles of approximately 90° or 130°, respectively. Where corner angles of wiggly CBs increase to 180°, they become straight CBs (T33). Image analyses of thin sections using an optical microscope show host rock porosity increases downslope in this dune, and the predominant type of wiggly CBs also varies from chevron to straight CBs. Specifically, band type varies continuously from chevron to wavy to straight where the porosity and grain sorting of the host rock increase systematically. Based on the crack and anticrack models, we infer that the change from chevron to straight CBs is due to increasing failure angle of the sandstone and this may correlate with increasing grain sorting. Wavy CBs with intermediate failure angle and host rock porosity are an intermediate stage between chevron and straight CBs. Previous sedimentological studies also have suggested that grain size and sorting degree increase downslope on the downwind side of sand dunes due to a sieving process of the wind-blown grains. Therefore, the transition of wiggly CB types in this regard correlates with increasing sorting and perhaps with increasing porosity downslope.

  13. The evolution of faults formed by shearing across joint zones in sandstone

    NASA Astrophysics Data System (ADS)

    Myers, Rodrick; Aydin, Atilla

    2004-05-01

    The evolution of strike-slip and normal faults formed by slip along joint zones is documented by detailed field studies in the Jurassic Aztec Sandstone in the Valley of Fire State Park, Nevada, USA. Zones of closely spaced planar sub-parallel joints arranged en échelon are sheared, forming faults. Fracturing occurs as a result of shearing, forming new joints. Later shearing along these joints leads to successively formed small faults and newer joints. This process is repeated through many generations of fracturing with increasing fault slip producing a hierarchical array of structures. Strain localization produced by shearing of joint zones at irregularities in joint traces, fracture intersections, and in the span between adjacent sheared joints results in progressive fragmentation of the weakened sandstone, which leads to the formation of gouge along the fault zone. The length and continuity of the gouge and associated slip surfaces is related to the slip magnitude and fault geometry with slip ranging from several millimeters to about 150 m. Distributed damage in a zone surrounding the gouge core is related to the original joint zone configuration (step sense, individual sheared joint overlaps and separation), shear sense, and slip magnitude. Our evolutionary model of fault development helps to explain some outstanding issues concerning complexities in faulting such as, the variability in development of fault rock and fault related fractures, and the failure processes in faults.

  14. Surface energy characterization of sandstone rocks

    NASA Astrophysics Data System (ADS)

    Arsalan, Naveed; Palayangoda, Sujeewa S.; Burnett, Daniel J.; Buiting, Johannes J.; Nguyen, Quoc P.

    2013-08-01

    The fundamental forces of adhesion are responsible for the spreading of fluids such as crude oil/brine on the reservoir rock surface. These physico-chemical interactions determine the surface energetics of a reservoir and thus their wetting phenomena. Inverse Gas Chromatography (IGC) is introduced to characterize the surface energy of sandstones (Ottawa sand and Berea sandstone). The surface chemistry of the sandstone rocks is further elucidated using X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) techniques. The behavior of the polar and non-polar interaction forces was investigated at varying water coverage and at different temperatures. The results indicated that in general as the water coverage increased, the Lifshitz-van der Waals component of surface energy decreased to nearly that of the bulk water, while the acid-base component also showed a decreasing trend. The Lifshitz-van der Waals component of surface energy always decreased with increase in temperature, while the acid-base properties showed contrasting trends in line with changes in surface chemistry of the sandstones, due to the change in temperature. Finally, the wetting properties arising in reservoir sandstones were related to the surface chemistry of the reservoir fluids and their interactions with the reservoir rock surface.

  15. New Perspectives on the Old Red Sandstone

    NASA Astrophysics Data System (ADS)

    Miall, Andrew D.

    The Old Red Sandstone is amongst the most distinctive and well-known stratigraphic units in the British Isles. It is mainly of Devonian age; in fact, its lower boundary was used to define the base of the Devonian until relatively recently and it was called "Old" back in the nineteenth century to distinguish it from a superficially similar succession of Triassic age named the New Red Sandstone. The Old Red Sandstone has long been known to be a non-marine syntectonic to post-tectonic deposit associated with the Caledonian Orogeny One of the most famous outcrops of the red sandstone is at Siccar Point in northeast England at one of several outcrops named "Hutton's unconformity" where it lies, with marked angularity on Silurian lithic sandstones and shales. It was at these outcrops, toward the end of the eigthteenth century that James Hutton first came to understand the meaning of angular unconformities as structures representing vast amounts of missing time during which major upheavals of the Earth's crust occurred.

  16. DEFORMATION AND FRACTURE OF POORLY CONSOLIDATED MEDIA - Borehole Failure Mechanisms in High-Porosity Sandstone

    SciTech Connect

    Bezalel c. Haimson

    2005-06-10

    We investigated failure mechanisms around boreholes and the formation of borehole breakouts in high-porosity sandstone, with particular interest to grain-scale micromechanics of failure leading to the hitherto unrecognized fracture-like borehole breakouts and apparent compaction band formation in poorly consolidated granular materials. We also looked at a variety of drilling-related factors that contribute to the type, size and shape of borehole breakouts. The objective was to assess their effect on the ability to establish correlations between breakout geometry and in situ stress magnitudes, as well as on borehole stability prediction, and hydrocarbon/water extraction in general. We identified two classes of medium to high porosity (12-30%) sandstones, arkosic, consisting of 50-70% quartz and 15 to 50% feldspar, and quartz-rich sandstones, in which quartz grain contents varied from 90 to 100%. In arkose sandstones critical far-field stress magnitudes induced compressive failure around boreholes in the form of V-shaped (dog-eared) breakouts, the result of dilatant intra-and trans-granular microcracking subparallel to both the maximum horizontal far-field stress and to the borehole wall. On the other hand, boreholes in quartz-rich sandstones failed by developing fracture-like breakouts. These are long and very narrow (several grain diameters) tabular failure zones perpendicular to the maximum stress. Evidence provided mainly by SEM observations suggests a failure process initiated by localized grain-bond loosening along the least horizontal far-field stress springline, the packing of these grains into a lower porosity compaction band resembling those discovered in Navajo and Aztec sandstones, and the emptying of the loosened grains by the circulating drilling fluid starting from the borehole wall. Although the immediate several grain layers at the breakout tip often contain some cracked or even crushed grains, the failure mechanism enabled by the formation of the

  17. Evaluating Reading Materials in Navajo: Report of a Teachers' Conference (Gallup, New Mexico, April 28-29, 1972). Navajo Reading Study Progress Report No. 18.

    ERIC Educational Resources Information Center

    Gradman, Harry L.; Young, Robert W.

    Elementary-grade reading materials produced in the Navajo language were evaluated at a teacher's conference held in Gallup, New Mexico, on April 28-29, 1972. Participants, mostly teachers, at the conference numbered approximately 45. The 5 texts evaluated were "Mosilgai" (School Cat), "Jasper," Pabii Doo Masi" (Puppy and Cat), "Da'iida" (Eat), and…

  18. Paleozoic to Jurassic terrane accretion along the northeastern margin of Tibet plateau

    NASA Astrophysics Data System (ADS)

    Neubauer, Franz; Liu, Yongjiang; Genser, Johann; Ren, Shoumai

    2010-05-01

    The Tibet plateau is considered to have been constructed by a number of basement terranes accreted to the Eurasian margin during Paleozoic to Mesozoic times, and accretion is interpreted to have progressed southwards. The northern margin, exposed in Altyn and Qilian Mountains, is generally considered as an Lower Paleozoic orogen including previously subducted ultra-high successions (Yin and Harrison, 2000; Xiao et al., 2009). Previous tectonic models of the Qaidam block and adjacent mountain ranges at the northeastern margin of the Tibet plateau assumed a minor role of Indosinian tectonism in that region, and firm evidence was only reported from eastern Kunlun Mountains (e.g., Liu et al., 2005). Based on four sources of new data, we propose that the Indosinian tectonism was much more widespread in the northeastern Qaidam block and adjacent mountain ranges, Altyn and Qilian Mts., as believed before and we propose a new tectonic model. The new data sources comprise: (1) 40Ar/39Ar dating of detrital white mica of Jurassic to Pliocene sandstones from the north-eastern Qaidam basin fill; (2) interpretation of Ordovician, Devonian and Jurassic sedimentary successions, from which we interpret the Jurassic successions as intramontane molasse to the Indosinian orogen; (3) 40Ar/39Ar dating of detrital white mica in recent rivers from the southern Qilian Shan revealing possible basement sources in the Qilian Shan draining towards the Qaidam basin; and (4) structural study of basement rocks and subordinate 40Ar/39Ar mineral ages of metamorphic basement rocks. An Ordovician greywacke exposed in the eastern Qaidam basin (W of Delinghua) yields three 40Ar/39Ar age groups of detrital white mica: 900-922, 610-654 and 527-554 Ma. Furthermore, similar old age groups centering at ca. 670 and 1010 Ma are virtually widespread in recent rivers from Qilian Mountains and clearly demonstrate the presence of Panafrican and Grenvillian tectonic elements in the southern Qilian Mts. at the

  19. Upper Jurassic and Lower Cretaceous facies relationships in a passive margin basin, western North Atlantic

    SciTech Connect

    Prather, B.E.

    1988-02-01

    Correlation of facies from hydrocarbon-bearing continental and transitional marine sandstones to time-equivalent high-energy shelf-margin carbonates provide insight into hydrocarbon habitats of the Baltimore Canyon basin. These facies occur within a thick (> 10,000 ft) prograded wedge of shelf sediments in this passive margin basin. Wells drilled to test structural closures in shallow-water (< 600 ft) areas of Baltimore Canyon penetrate clastic facies which are time-equivalent to the downdip carbonate facies tested in deep-water wells. Numerous hydrocarbon shows, including a noncommercial gas and gas-condensate accumulation, occur with sandstone units that were deposited in prograding continental/fluvial and transitional marine environments located updip of the Oxfordian/Kimmeridgian carbonate shelf edge. The continental and transitional facies are overlain by a fine-grained deltaic complex which forms a regionally extensive top seal unit. The deltaic complex was deposited during aggradation of the Kimmeridgian through Berriasian shelf-margin carbonates penetrated by the deep-water wells. Deep-water wells (> 5000 ft) drilled off the continental shelf edge to test large structural closures along the downdip termination of the Upper Jurassic/Lower Cretaceous carbonate shelf edge encountered no significant hydrocarbon shows. Reservoir rocks in these wells consist of (1) oolite grainstone which was deposited within a shoal-water complex located at the Aptian shelf edge, and (2) coral-stromatoporoid grainstone and boundstone which formed an aggraded shelf-margin complex located at the Kimmeridgian through Berriasian shelf edge. Structural closures with reservoir and top seals are present in both updip and downdip trends. The absence of hydrocarbon shows in downdip carbonate reservoirs suggests a lack of source rocks available to charge objectives at the shelf margin.

  20. Natural gas plays in Jurassic reservoirs of southwestern Alabama and the Florida panhandle area

    SciTech Connect

    Mancini, E.A. Univ. of Alabama, Tuscaloosa ); Mink, R.M.; Tew, B.H.; Bearden, B.L. )

    1990-09-01

    Three Jurassic natural gas trends can be delineated in Alabama and the Florida panhandle area. They include a deep natural gas trend, a natural gas and condensate trend, and an oil and associated natural gas trend. These trends are recognized by hydrocarbon types, basinal position, and relationship to regional structural features. Within these natural gas trends, at least eight distinct natural gas plays can be identified. These plays are recognized by characteristic petroleum traps and reservoirs. The deep natural gas trend includes the Mobile Bay area play, which is characterized by faulted salt anticlines associated with the Lower Mobile Bay fault system and Norphlet eolian sandstone reservoirs exhibiting primary and secondary porosity at depths exceeding 20,000 ft. The natural gas and condensate trend includes the Mississippi Interior Salt basin play, Mobile graben play, Wiggins arch flank play, and the Pollard fault system play. The Mississippi Interior Salt basin play is typified by salt anticlines associated with salt tectonism in the Mississippi Interior Salt basin and Smackover dolomitized peloidal and pelmoldic grainstone and packstone reservoirs at depths of approximately 16,000 ft. The Mobile graben play is exemplified by faulted salt anticlines associated with the Mobile graben and Smackover dolostone reservoirs at depths of approximately 18,000 ft. The Wiggins arch flank play is characterized by structural traps consisting of salt anticlines associated with stratigraphic thinning and Smackover dolostone reservoirs at depths of approximately 18,000 ft. The Pollard fault system play is typified by combination petroleum traps. The structural component is associated with the Pollard fault system and reservoirs at depths of approximately 15,000 ft. These reservoirs are dominantly Smackover dolomitized oomoldic and pelmoldic grainstones and packstones and Norphlet marine, eolian, and wadi sandstones exhibiting primary and secondary porosity.

  1. Triassic/Jurassic faulting patterns of Conecuh Ridge, southwest Alabama

    SciTech Connect

    Hutley, J.K.

    1985-02-01

    Two major fault systems influenced Jurassic structure and deposition on the Conecuh Ridge, southwest Alabama. Identification and dating of these fault systems are based on seismic-stratigraphic interpretation of a 7-township grid in Monroe and Conecuh Counties. Relative time of faulting is determined by fault geometry and by formation isopachs and isochrons. Smackover and Norphlet Formations, both Late Jurassic in age, are mappable seismic reflectors and are thus reliable for seismicstratigraphic dating. The earlier of the 2 fault systems is a series of horsts and grabens that trends northeast-southwest and is Late Triassic to Early Jurassic in age. The system formed in response to tensional stress associated with the opening of the Atlantic Ocean. The resulting topography was a series of northeast-southwest-trending ridges. Upper Triassic Eagle Mills and Jurassic Werner Formations were deposited in the grabens. The later fault system is also a series of horsts and grabens trending perpendicular to the first. This system was caused by tensional stress related to a pulse in the opening of the Gulf of Mexico. Faulting began in Early Jurassic and continued into Late Jurassic, becoming progressively younger basinward. At the basin margin, faulting produced a very irregular shoreline. Submerged horst blocks became centers for shoaling or carbonate buildups. Today, these blocks are exploration targets in southwest Alabama.

  2. Late Jurassic plutonism in the southwest U.S. Cordillera

    USGS Publications Warehouse

    Barth, A.P.; Wooden, J.L.; Howard, K.A.; Richards, J.L.

    2008-01-01

    Although plate reconstructions suggest that subduction was an approximately steady-state process from the mid-Mesozoic through the early Tertiary, recent precise geochronologic studies suggest highly episodic emplacement of voluminous continental-margin batholiths in the U.S. Cordillera. In central and southern California and western Arizona, major episodes of batholithic magmatism are known to have occurred in Permian-Triassic, Middle Jurassic, and late Early to Late Cretaceous time. However, recent studies of forearc-basin and continental-interior sediments suggest that Late Jurassic time was probably also a period of significant magmatism, although few dated plutons of this age have been recognized. We describe a belt of Late Jurassic plutonic and hypabyssal rocks at least 200 km in length that extends from the northwestern Mojave Desert through the Transverse Ranges. The belt lies outboard of both the voluminous Middle Jurassic arc and the ca. 148 Ma Independence dike swarm at these latitudes. The plutons include two intrusive suites emplaced between 157 and 149 Ma: a calc-alkaline suite compositionally unlike Permian-Triassic and Middle Jurassic mon-zonitic suites but similar to Late Cretaceous arc plutons emplaced across this region, and a contemporaneous but not comagmatic alkaline suite. The Late Jurassic was thus a time of both tectonic and magmatic transitions in the southern Cordillera. ?? 2008 The Geological Society of America.

  3. Polygonal cracks in bedrock on Earth and Mars: Implications for weathering

    NASA Astrophysics Data System (ADS)

    Chan, Marjorie A.; Yonkee, W. Adolph; Netoff, Dennis I.; Seiler, Winston M.; Ford, Richard L.

    2008-03-01

    Polygonal crack systems with domal microrelief imaged by the Mars Exploration Rover (MER) Opportunity show remarkable similarity to terrestrial crack systems developed on outcrop surfaces. Study of Jurassic Navajo Sandstone surfaces show development of crack systems in relatively isotropic host rock as a result of tensile weathering stresses. These terrestrial analogs are utilized to understand potential weathering processes on Mars.

  4. Dinosaur ichnofauna of the Upper Jurassic/Lower Cretaceous of the Paraná Basin (Brazil and Uruguay)

    NASA Astrophysics Data System (ADS)

    Francischini, H.; Dentzien–Dias, P. C.; Fernandes, M. A.; Schultz, C. L.

    2015-11-01

    Upper Jurassic and Lower Cretaceous sedimentary layers are represented in the Brazilian Paraná Basin by the fluvio-aeolian Guará Formation and the Botucatu Formation palaeoerg, respectively, overlapped by the volcanic Serra Geral Formation. In Uruguay, the corresponding sedimentary units are named Batoví and Rivera Members (both from the Tacuarembó Formation), and the lava flows constitute the Arapey Formation (also in Paraná Basin). Despite the lack of body fossils in the mentioned Brazilian formations, Guará/Batoví dinosaur fauna is composed of theropod, ornithopod and wide-gauge sauropod tracks and isolated footprints, as well as theropod teeth. In turn, the Botucatu/Rivera dinosaur fauna is represented by theropod and ornithopod ichnofossils smaller than those from the underlying units. The analysis of these dinosaur ichnological records and comparisons with other global Mesozoic ichnofauna indicates that there is a size reduction in dinosaur fauna in the more arid Botucatu/Rivera environment, which is dominated by aeolian dunes. The absence of sauropod trackways in the Botucatu Sandstone fits with the increasingly arid conditions because it is difficult for heavy animals to walk on sandy dunes, as well as to obtain the required amount of food resources. This comparison between the Upper Jurassic and Lower Cretaceous dinosaur fauna in south Brazil and Uruguay demonstrates the influence of aridization on the size of animals occupying each habitat.

  5. Navajo birth outcomes in the Shiprock uranium mining area

    SciTech Connect

    Shields, L.M.; Wiese, W.H.; Skipper, B.J.; Charley, B.; Benally, L. )

    1992-11-01

    The role of environmental radiation in the etiology of birth defects, stillbirths, and other adverse outcomes of pregnancy was evaluated for 13,329 Navajos born at the Public Health Service/Indian Health Service Hospital in the Shiprock, NM, uranium mining area (1964-1981). More than 320 kinds of defective congenital conditions were abstracted from hospital records. Using a nested case-control design, families of 266 pairs of index and control births were interviewed. The only statistically significant association between uranium operations and unfavorable birth outcome was identified with the mother living near tailings or mine dumps. Among the fathers who worked in the mines, those of the index cases had histories of more years of work exposure but not necessarily greater gonadal dosage of radiation. Also, birth defects increased significantly when either parent worked in the Shiprock electronics assembly plant. Overall, the associations between adverse pregnancy outcome and exposure to radiation were weak and must be interpreted with caution with respect to implying a biogenetic basis.

  6. Using cultural knowledge in health promotion: breastfeeding among the Navajo.

    PubMed

    Wright, A L; Naylor, A; Wester, R; Bauer, M; Sutcliffe, E

    1997-10-01

    Although many attempts have been made to promote breastfeeding in a variety of contexts, few programs have explicitly incorporated cultural beliefs in these efforts. This article describes a breastfeeding promotion program conducted on the Navajo reservation. This program was designed to be culturally appropriate. Background information regarding beliefs and factors affecting infant feeding practices in this setting is provided, followed by a description of the intervention. The intervention, which incorporated both social marketing and community participation techniques, consisted of three components: an intervention in the health care system, a community intervention, and an individual intervention. Based on medical records review of feeding practices of all the infants born the year before (n = 988) and the year after (n = 870) the intervention, the program was extremely successful. This combination of techniques, including qualitative and quantitative research into local definitions of the problem, collaboration with local institutions and individuals, reinforcement of traditional understandings about infant feeding, and institutional change in the health care system, is an effective way of facilitating behavioral change. PMID:9307898

  7. Total petroleum systems of the Bonaparte Gulf Basin area, Australia; Jurassic, Early Cretaceous-Mesozoic; Keyling, Hyland Bay-Permian; Milligans-Carboniferous, Permian

    USGS Publications Warehouse

    Bishop, M.G.

    1999-01-01

    The Bonaparte Gulf Basin Province (USGS #3910) of northern Australia contains three important hydrocarbon source-rock intervals. The oldest source-rock interval and associated reservoir rocks is the Milligans-Carboniferous, Permian petroleum system. This petroleum system is located at the southern end of Joseph Bonaparte Gulf and includes both onshore and offshore areas within a northwest to southeast trending Paleozoic rift that was initiated in the Devonian. The Milligans Formation is a Carboniferous marine shale that sources accumulations of both oil and gas in Carboniferous and Permian deltaic, marine shelf carbonate, and shallow to deep marine sandstones. The second petroleum system in the Paleozoic rift is the Keyling, Hyland Bay-Permian. Source rocks include Lower Permian Keyling Formation delta-plain coals and marginal marine shales combined with Upper Permian Hyland Bay Formation prodelta shales. These source-rock intervals provide gas and condensate for fluvial, deltaic, and shallow marine sandstone reservoirs primarily within several members of the Hyland Bay Formation. The Keyling, Hyland Bay-Permian petroleum system is located in the Joseph Bonaparte Gulf, north of the Milligans-Carboniferous, Permian petroleum system, and may extend northwest under the Vulcan graben sub-basin. The third and youngest petroleum system is the Jurassic, Early Cretaceous-Mesozoic system that is located seaward of Joseph Bonaparte Gulf on the Australian continental shelf, and trends southwest-northeast. Source-rock intervals in the Vulcan graben sub-basin include deltaic mudstones of the Middle Jurassic Plover Formation and organic-rich marine shales of the Upper Jurassic Vulcan Formation and Lower Cretaceous Echuca Shoals Formation. These intervals produce gas, oil, and condensate that accumulates in, shallow- to deep-marine sandstone reservoirs of the Challis and Vulcan Formations of Jurassic to Cretaceous age. Organic-rich, marginal marine claystones and coals of the

  8. Seismic Response of Carbonate Cemented Sandstones

    NASA Astrophysics Data System (ADS)

    Dutta, T.; Mukerji, T.; Mavko, G.

    2007-12-01

    This study focuses on how carbonate cementation precipitated at the key sequence stratigraphic surfaces impact the seismic impedance. Our goals are two-fold: (1) to identify the sedimentological variations within carbonate- cemented sandstones and (2) to quantify their effects on P-impedance. To accomplish this goal, we identify the relationship between carbonate cementation and key stratigraphic surfaces, such as, the incision surfaces and the flooding surfaces. Next, we use effective medium models to quantify the impact of sediment parameters on P- impedance. We find that the carbonate cemented sandstones are extremely heterogeneous in nature, even within a depth interval of 60 meter in our study area offshore Equatorial Guinea, West Africa. Their grain-size, sorting, mineralogy, clay-content, amount of cement and degree of leaching vary considerably. We identify two distinct clusters of data in the P-impedance vs. porosity plane. The carbonate cemented sandstones from the base of incision are usually associated with lower shaliness, lower porosity and higher P-impedance. On the contrary, data from the top of flooding surfaces exhibit higher shaliness, higher porosity and lower P-impedance. The contact cement model fails to predict the trend shown by the later cluster of data. The predictions using the constant cement model with 1% constant carbonate cement, and the modified stiffsand model with 15% critical porosity agree reasonably well with the data. Furthermore, we find that the modified differential effective media model with 40% percolation porosity, and Berryman's self consistent model with 20% percolation porosity fit P- impedance vs. porosity trend of the carbonated cemented sandstones. In conclusion, the carbonate cements are different than the siliciclastic cements in terms of sedimentological parameters, and the commonly used rock physics model for quartz cemented sandstones are not always suitable to predict P-impedance vs. porosity trends for the

  9. Delayed onset sandstone pneumoconiosis: a case report

    SciTech Connect

    Symanski, H.

    1981-01-01

    An unusual case of silicosis is described in a worker who inhaled the dust of pure silica while working in a sandstone quarry. The exposure lasted only eight years. In 1980, 45 years after exposure ceased, severe clinical manifestations of silicosis appeared for the first time. The chest X-ray showed a pneumoconiosis A 2mn/A2 Mn Cor, em, hilus, based on the International Classification of Geneva, 1958. A diagnosis of sandstone pneumoconiosis was made. The case is one further example of late-occurring disease appearing after a latency of several decades.

  10. Livestock grazing for management of reclaimed land at Navajo Mine: Animal response

    SciTech Connect

    Gamble, D.C.; Gadzia, K.L.; Raisbeck, M.F.

    1997-12-31

    Livestock responses dining grazing of reclaimed land were monitored at the Navajo Mine since 1994. The Navajo Mine Grazing Management Program (GNP) began in 1991 to prepare for bond release and return of reclaimed land to the Navajo Nation by demonstrating the ability of the land to sustain the post-mining land use of livestock grazing. Local Navajos, whose livestock are used in the GMP, are interested in the ability of the land to sustain their livestock. Sustainable livestock grazing implies the ability of animals to thrive, successfully reproduce and maintain the health of the land. Daily care and monitoring of livestock health was carried out by herders hired by the mining company. General animal health parameters including blood selenium levels were monitored quarterly. Livestock responses to grazing reclaimed land have been largely positive. Cows have produced healthy offspring and owners indicate satisfaction with calf size, and overall performance of the cows. Selenium and other blood testing parameters indicate no adverse effect on animal health to date. Hazards associated with reclamation and ongoing mining activities are important considerations for lands being reclaimed for livestock grazing as a post-mining land use and must be monitored carefully during any grazing program. Preliminary results indicate that planned grazing by cattle on reclaimed land at Navajo Mine is feasible and does not adversely affect animal health.

  11. Spirometry reference values for Navajo children ages 6-14 years.

    PubMed

    Arnall, David A; Kanuho, Verdell; Interpreter, Christina; Nelson, Arnold G; Coast, J Richard; Eisenmann, Joey C; Enright, Paul L

    2009-05-01

    Spirometry is the most important tool in diagnosing pulmonary disease and is the most frequently performed pulmonary function test. Since respiratory disease is the single greatest cause for morbidity and mortality on the Navajo Nation, the purpose of this study was to create new age and race-specific pulmonary nomograms for Navajo children. Five hundred fifty-eight healthy children, ages 6-14 years, attending Navajo Nation elementary schools in Arizona, were asked to perform spirometry to develop population-specific and tribe-specific nomograms for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1 Ratio (FEV1/FVC). Spirometry tests from 284 girls and 274 boys met American Thoracic Society quality control standards. Lung function values, except for FEV1/FVC, all increased with height. The lower limit of the normal range for FEV1/FVC was 80%. The spirometry reference equations from the healthy boys and girls were developed. Height and the natural log of height were significant predictors of FEV1, FVC, and FEF(25-75%) in the gender-specific models. The resulting population-specific spirometry reference equations should be used when testing Navajo children ages 6-14 years. However, the use of the NHANES III spirometry reference equations for Caucasian children may not result in significant misclassification in clinical settings providing that a maximal effort is given by the Navajo child being tested. PMID:19360844

  12. A Feasibility Study to Evaluate Wind Energy Potential on the Navajo Nation

    SciTech Connect

    Terry Battiest

    2012-11-30

    The project, A Feasibility Study to Evaluate Wind Energy Potential on the Navajo Nation, is funded under a solicitation issued by the U.S. Department of Energy Tribal Energy Program. Funding provided by the grant allowed the Navajo Nation to measure wind potential at two sites, one located within the boundaries of the Navajo Nation and the other off-reservation during the project period (September 5, 2005 - September 30, 2009). The recipient for the grant award is the Navajo Tribal Utility Authority (NTUA). The grant allowed the Navajo Nation and NTUA manage the wind feasibility from initial site selection through the decision-making process to commit to a site for wind generation development. The grant activities help to develop human capacity at NTUA and help NTUA to engage in renewable energy generation activities, including not only wind but also solar and biomass. The final report also includes information about development activities regarding the sited included in the grant-funded feasibility study.

  13. Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.

    USGS Publications Warehouse

    Whitney, G.; Northrop, H.R.

    1987-01-01

    The Westwater Canyon Member of the Upper Jurassic Morrison Formation is a relatively homogeneous, hydrologically continuous 100-m-thick sequence of massive fluvial sandstone, bounded above and below by relatively heterogeneous, hydrologically discontinuous units and has served as a primary conduit for fluids within this stratigraphic interval. Patterns of mineral-fluid reactions suggest a basinwide hydrologic regime in which warm, evolved fluids migrated up-dip from the center of the basin under the influence of a regional hydraulic head. -from Authors

  14. Late Jurassic salamanders from northern China.

    PubMed

    Gao, K Q; Shubin, N H

    2001-03-29

    With ten extant families, salamanders (urodeles) are one of the three major groups of modern amphibians (lissamphibians). Extant salamanders are often used as a model system to assess fundamental issues of developmental, morphological and biogeographical evolution. Unfortunately, our understanding of these issues has been hampered by the paucity of fossil evidence available to assess the early history of the group. Here we report the discovery of an extraordinary sample of salamander fossils, some with rare soft-tissue impressions, from the Upper Jurassic of China. With over 500 articulated specimens, this assemblage documents the morphological diversity of early urodeles and includes larvae and adults of both neotenic and metamorphosed taxa. Phylogenetic analysis confirms that these salamanders are primitive, and reveals that all basal salamander clades have Asian distributions. This is compelling evidence for an Asian origin of Recent salamanders, as well as for an extensive and early radiation of several major lineages. These discoveries show that the evolution of salamanders has involved phylogenetic and ecological diversification around a body plan that has remained fundamentally stable for over 150 million years. PMID:11279493

  15. Testing Iberia Kinematics at Jurassic-Cretaceous

    NASA Astrophysics Data System (ADS)

    Neres, Marta; Miranda, J. Miguel; Font, Eric

    2013-04-01

    Paleogeographic reconstructions of Iberia at Mesozoic are still a matter of debate. A major problem resides in the incompatibility existing between kinematic models and paleomagnetic data older than 120 Ma. Here, we investigate the origin of this misfit by finding and testing euler poles that fit Iberian mean paleomagnetic poles (123, 130 and 151 Ma) with global APWP. At 123 Ma 130 Ma, no geologically plausible solutions were found, questioning the validity of corresponding paleomagnetic data. Contrarily, for 151 Ma mean pole, coherent solutions were simulated, suggesting respective paleomagnetic data as potentially reliable. Based on these results, we propose a new magnetic reconstruction for Iberia and surrounding plates at ~150 Ma, to which corresponds the IB-NAM euler pole -18.08 / 67.54 / -57.72 (long / lat / angle). This is the first pre-drift reconstruction for Iberia to be compatible with paleomagnetic data. A complete and coherent model for the Jurassic-Cretaceous kinematic evolution of Iberia is still dependent on more and better paleomagnetic poles and on a reevaluation of magnetic anomalies, for which several problems remain unsolved.

  16. Concurrent and Longitudinal Effects of Ethnic Identity and Experiences of Discrimination on Psychosocial Adjustment of Navajo Adolescents

    ERIC Educational Resources Information Center

    Galliher, Renee V.; Jones, Matthew D.; Dahl, Angie

    2011-01-01

    In this study, we examined concurrent and longitudinal relations among Navajo adolescents' ethnic identity, experiences of discrimination, and psychosocial outcomes (i.e., self-esteem, substance use, and social functioning). At Time 1, 137 Navajo adolescents (67 male, 70 female), primarily in Grades 9 and 10, completed a written survey assessing…

  17. "Enemies Like a Road Covered with Ice": The Utah Navajos' Experience during the Long Walk Period, 1858-1868

    ERIC Educational Resources Information Center

    Hornsby, Sarah; McPherson, Robert S.

    2009-01-01

    Much has been written of the Navajo Long Walk period when the Navajo people, following what appears to be a fairly short resistance, surrendered in droves to the US military, collected at Fort Defiance and other designated sites, then moved in a series of "long walks" to Fort Sumner (Hweeldi) on the Pecos River in eastern New Mexico. There was…

  18. The Role of Education in American Indian Self-Determination: Lessons from the Ramah Navajo Community School

    ERIC Educational Resources Information Center

    Manuelito, Kathryn

    2005-01-01

    Since 1975 the Indian Self-Determination and Educational Assistance Act has enabled American Indian communities to enact self-determination through community-based schooling. In this study conducted by a Navajo researcher, the Ramah Navajo community defined self-determination and how it was operationalized within the community and school. The…

  19. 78 FR 2685 - Notice of Intent To Prepare a Programmatic Environmental Impact Statement (EIS) for the Navajo...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ...) for the Navajo Nation Integrated Weed Management Plan Within Coconino, Navajo, and Apache Counties... Department of Transportation serving as cooperating agencies, intends to prepare an EIS for a proposed weed... . SUPPLEMENTARY INFORMATION: The BIA is proposing to develop a ten-year integrated weed management plan for...

  20. A Giant Pliosaurid Skull from the Late Jurassic of England

    PubMed Central

    Benson, Roger B. J.; Evans, Mark; Smith, Adam S.; Sassoon, Judyth; Moore-Faye, Scott; Ketchum, Hilary F.; Forrest, Richard

    2013-01-01

    Pliosaurids were a long-lived and cosmopolitan group of marine predators that spanned 110 million years and occupied the upper tiers of marine ecosystems from the Middle Jurassic until the early Late Cretaceous. A well-preserved giant pliosaurid skull from the Late Jurassic Kimmeridge Clay Formation of Dorset, United Kingdom, represents a new species, Pliosaurus kevani. This specimen is described in detail, and the taxonomy and systematics of Late Jurassic pliosaurids is revised. We name two additional new species, Pliosaurus carpenteri and Pliosaurus westburyensis, based on previously described relatively complete, well-preserved remains. Most or all Late Jurassic pliosaurids represent a globally distributed monophyletic group (the genus Pliosaurus, excluding ‘Pliosaurus’ andrewsi). Despite its high species diversity, and geographically widespread, temporally extensive occurrence, Pliosaurus shows relatively less morphological and ecological variation than is seen in earlier, multi-genus pliosaurid assemblages such as that of the Middle Jurassic Oxford Clay Formation. It also shows less ecological variation than the pliosaurid-like Cretaceous clade Polycotylidae. Species of Pliosaurus had robust skulls, large body sizes (with skull lengths of 1.7–2.1 metres), and trihedral or subtrihedral teeth suggesting macropredaceous habits. Our data support a trend of decreasing length of the mandibular symphysis through Late Jurassic time, as previously suggested. This may be correlated with increasing adaptation to feeding on large prey. Maximum body size of pliosaurids increased from their first appearance in the Early Jurassic until the Early Cretaceous (skull lengths up to 2360 mm). However, some reduction occurred before their final extinction in the early Late Cretaceous (skull lengths up to 1750 mm). PMID:23741520

  1. The role of true polar wander on the Jurassic palaeoclimate

    NASA Astrophysics Data System (ADS)

    Iglesia Llanos, María Paula; Prezzi, Claudia Beatriz

    2013-04-01

    From the Late Carboniferous until the Middle Jurassic, continents were assembled in a quasi-rigid supercontinent called Pangea. The first palaeomagnetic data of South America indicated that the continent remained stationary in similar present-day latitudes during most of the Mesozoic and even the Palaeozoic. However, new palaeomagnetic data suggest that such a scenario is not likely, at least for the Jurassic. In order to test the stationary versus the dynamic-continent model, we studied the Jurassic apparent polar wander paths of the major continents, that is, Eurasia, Africa and North America that all in all show the same shape and chronology of the tracks with respect to those from South America. We thus present a master path that could be useful for the Jurassic Pangea. One of the most remarkable features observed in the path is the change in pole positions at ~197 Ma (Early Jurassic), which denotes the cessation of the counter-clockwise rotation of Pangea and commencement of a clockwise rotation that brought about changes in palaeolatitude and orientation until the end of the Early Jurassic (185 Ma). Here, we analyse a number of phenomena that could have triggered the polar shift between 197 and 185 Ma and conclude that true polar wander is the most likely. In order to do this, we used Morgan's (Tectonophysics 94:123-139, 1983) grid of hotspots and performed "absolute" palaeogeographical reconstructions of Pangea for the Late Triassic and Jurassic. The palaeolatitudes changes that we observe from our palaeomagnetic data are very well sustained by diverse palaeoclimatic proxies derived from geological and palaeoecological data at this time of both the southern and northern hemispheres.

  2. Sedimentological evolution, diagenesis and hydrocarbon potentiality of late Jurassic carbonates, Eastern Region, Yemen Arab Republic

    SciTech Connect

    El-anbaawy, M.I.H.; Al-thour, K.A. )

    1989-01-01

    On the basis of the lateral and vertical distribution of the lithofacies identified within the Late Jurassic Amran sequence (Thoma Member) in Jabal Al-Balaq area, Marib, Y.A.R., three megafacies were recognized. Proceeding from the shore landwards they are: Ooid bank, including barriers such as reefs and carbonate sand shoals adjacent to the margin of a shallow platform having intertidal to subtidal agitated water, the bank being composed of skeletal packstone, oolitic grainstone and oncolitic packstone; Shelf lagoon, behind the shoal, characterized by less turbulent pelletoidal wackestone, sandy mudstone and algal stromatolite (boundstone); Alluvial coastal plain, including tidal sand flat of the marine shoreline-intertidal area, where cross-bedded sandstone and alluvial fan toe conglomerate were deposited. The apparent small-scale facies variations which are the result of the allocyclic tectonically controlled sea level fluctuations, reflect a complex interfingering of the depositional environments and the resulting rock types. The paragenetic sequence of the post-depositional processes within the siliciclastics inferred is: iron oxide cementation, authigenic growth of mica clays, generation of pressure solution and compaction, and generation of quartz overgrowths. It is indicated that the compaction process followed the neomorphism and cementation within the carbonates.

  3. Late Jurassic to Early Cretaceous Radiolaria from chert blocks in the Lubok Antu melange, Sarawak, Malaysia

    NASA Astrophysics Data System (ADS)

    Jasin, Basir

    The Lubok Antu melange is composed of blocks of mudstone, shale, sandstone, chert, limestone, hornfels, basalt, gabbro and serpentinite embedded in a strongly cleaved, pervasively sheared, chloritised mudstone matrix. Chert blocks are common and widespread in the melange. Fifty-three species of Radiolaria were identified from 14 samples collected from these chert blocks. The Radiolaria can be grouped into three assemblages. Assemblage I is composed of 17 species. The presence of Ristola altissima (Rüst) and Parvicingula excelsa Pessagno and Blome is indicative of late Tithonian (Late Jurassic). Assemblage II consists of 21 species. The occurrence of an index form Staurosphaera septemporata (Parona) indicates middle Valanginian to Barremian age. The presence of Squinabollum fossilis (Squinabol), Archaeodictyomitra vulgaris Pessagno, Obesacapsula somphedia (Foreman), Thanarla praeveneta Pessagno, Pseudodictyomitra pseudomacrocephala (Squinabol), Rhopalosyringium majuroensis Schaaf, Stichomitra communis Squinabol and Holocryptocanium tuberculatum Dumitrica in Assemblage III suggests that the age of this assemblage is late Albian to Cenomanian. All the results show that there are three different ages of the chert blocks present in the Lubok Antu melange.

  4. Fractures and stresses in Bone Spring sandstones

    SciTech Connect

    Lorenz, J.C.; Warpinski, N.R.; Sattler, A.R.; Northrop, D.A.

    1990-09-01

    This project is a collaboration between Sandia National Laboratories and Harvey E. Yates Company being conducted under the auspices of the Oil Recovery Technology Partnership. The project seeks to apply perspectives related to the effects of natural fractures, stress, and sedimentology to the simulation and production of low-permeability gas reservoirs to low-permeability oil reservoirs as typified by the Bone Spring sandstones of the Permian Basin, southeast New Mexico. This report presents the results and analysis obtained in 1989 from 233 ft of oriented core, comprehensive suite of logs, various in situ stress measurements, and detailed well tests conducted in conjunction with the drilling of two development wells. Natural fractures were observed in core and logs in the interbed carbonates, but there was no direct evidence of fractures in the sandstones. However, production tests of the sandstones indicated permeabilities and behavior typical of a dual porosity reservoir. A general northeast trend for the maximum principal horizontal stress was observed in an elastic strain recovery measurements and in strikes of drilling-induced fractures; this direction is subparallel to the principal fracture trend observed in the interbed carbonates. Many of the results presented are believed to be new information for the Bone Spring sandstones. 57 figs., 18 tabs.

  5. Diabetes on the Navajo nation: what role can gardening and agriculture extension play to reduce it?

    PubMed

    Lombard, Kevin A; Forster-Cox, Susan; Smeal, Dan; O'Neill, Mick K

    2006-01-01

    Diabetes has emerged as a serious health problem in the Navajo nation, the largest Indigenous tribe in the US. Persons with diabetes are at greater risk for developing other diseases such as cardiovascular disease. Navajos with diabetes almost certainly face a diminished quality of life if their diabetes is not managed properly. Aside from genetics, the incidence of diabetes is highly correlated with income, poor diet, and limited physical exercise. A review of the literature also implicates dietary shifts initiated by historical events and contemporary trends. Numerous studies have shown that moderate consumption of fruits and vegetables, combined with exercise, reduces the risk of or delays the onset of many diseases including diabetes. As part of a larger holistic approach, home and community garden projects have successfully addressed nutrition and food security issues on a grassroots scale. The Navajos have a tradition of farming and therefore expanding Navajo diabetes interventions to include the promotion of community and home gardens provides multiple opportunities. The benefits of these actions include: (i) a variety of nutritious food grown locally; (ii) physical activity attained through the act of daily gardening tasks; (iii) positive income garnered in terms of savings in food otherwise purchased at stores and excess produce canned, or if desired, sold at a farmer's market or trading post; and (iv) positive mental outlook through a combined sense of accomplishment at harvest time, bonding with the earth, and spiritual growth. The objectives of this article were to review the development of diabetes on the Navajo nation though historical and contemporary literature, to provide insight into the role of diet and exercise in the progression of the disease, and to offer cases and suggestions in the role that home and community gardening can play in diabetes reduction. A concluding discussion proposes a multidisciplinary approach to tackling diabetes on the

  6. Supraregional seismites in Triassic - Jurassic boundary strata

    NASA Astrophysics Data System (ADS)

    Lindström, Sofie; Pedersen, Gunver K.; van de Schootbrugge, Bas; Johansson, Leif; Petersen, Henrik I.; Dybkjær, Karen; Weibel, Rikke; Hansen, Katrine H.; Erlström, Mikael; Alwmark, Carl; Nielsen, Lars Henrik; Oschmann, Wolfgang; Tegner, Christian

    2014-05-01

    The end-Triassic mass extinction event (201.564 Ma) was synchronous with the earliest volcanic phase during the emplacement of the Central Atlantic Magmatic Province (CAMP), a large igneous province (LIP) formed during the initial breakup of Pangea. Volcanic degassing of CO2 and other volatile gases, and/or thermogenic methane, from the CAMP is generally regarded as the main cause of the end-Triassic biotic crisis. However, discrepancies in the durations of the ETE (50 Kyrs) and the CAMP volcanism (600 Kyrs) as well as temporal offsets between carbon cycle perturbations and biotic turnovers suggest a more complex scenario that require further studies of the temporal succession of events in Triassic-Jurassic (TJ) boundary strata. Here, we present and examine multiple episodes of soft-sediment deformation (seismite) within uppermost Rhaetian marine and terrestrial strata of Denmark, Sweden and Germany. These seismites are stratigraphically constrained by palynology and C-isotopes to the latest Rhaetian, and are synchronous to the single seismite layer from the UK, which similarly predates the T/J boundary, and has been explained by an extraterrestrial bolide impact. Instead, we argue that the multiple episodes of soft-sediment deformation, interbedded by undisturbed strata, were formed from repeated intense earthquake activity restricted to an interval within the latest Rhaetian bracketed by two negative excursions in δ13C and also containing palynological evidence for deforestation and fern proliferation. The fact that these biotic changes coincide with repeated seismic activity has implications for the end-Triassic extinction and the CAMP scenario. We discuss the temporal position of the seismites in regards to other end-Triassic events, and argue that their supraregional distribution in pre-TJ-boundary strata of NW Europe may be linked to intensified earthquake activity during CAMP emplacement, rather than an extraterrestrial impact.

  7. Emplacement of sandstone intrusions during contractional tectonics

    NASA Astrophysics Data System (ADS)

    Palladino, Giuseppe; Grippa, Antonio; Bureau, Denis; Alsop, G. Ian; Hurst, Andrew

    2016-08-01

    Sandstone injections are created by the forceful emplacement of remobilized sand in response to increases in overpressure. However, the contribution provided by horizontal compressive stress to the build-up in overpressure, and the resulting emplacement of sand injection complexes, is still to be substantiated by robust field observations. An opportunity to address this issue occurs in Central California where a large volume of sandstone intrusions record regionally-persistent supra-lithostatic pore-pressure. Detailed fieldwork allows sandstone-filled thrusts to be recognized and, for the first time, permits us to demonstrate that some sandstone intrusions are linked to contractional deformation affecting the western border of the Great Valley Basin. Fluidized sand was extensively injected along thrust surfaces, and also fills local dilatant cavities linked to thrusting. The main aims of this paper are to provide detailed descriptions of the newly recognized syn-tectonic injections, and describe detailed cross-cutting relationships with earlier sandstone injection complexes in the study area. Finally, an evolutionary model consisting of three phases of sand injection is provided. In this model, sand injection is linked to contractional tectonic episodes affecting the western side of the Great Valley Basin during the Early-Middle Cenozoic. This study demonstrates that sand injections, driven by fluid overpressure, may inject along thrusts and folds and thereby overcome stresses associated with regional contractional deformation. It is shown that different generations of sand injection can develop in the same area under the control of different stress regimes, linked to the evolving mountain chain.

  8. Early Jurassic black shales: Global anoxia or regional "Dead Zones"?

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, B.; Payne, J.; Wignall, P.

    2012-12-01

    The so-called "Schwarzer Jura" or "Black Jurassic" in Germany is informally used to designate a series of organic-rich sediments that roughly span the Early Jurassic (201.6 - 175.6 Myr), and which culminate in the Toarcian Oceanic Anoxic Event. Based on organic and inorganic geochemical as well as (micro)palaeontological data from several recently drilled cores, black shales deposited directly following the end-Triassic extinction (201.6 Ma) during the Hettangian are extremely similar to Toarcian black shales. Both events are characterized by laminated black shales that contain high amounts of the biomarker isorenieratane, a fossilized pigment derived from green sulphur bacteria. Furthermore, the two intervals show similar changes in phytoplankton assemblages from chromophyte (red) to chlorophyte (green) algae. Combined, the evidence suggests that photic zone euxinia developed repeatedly during the Early Jurassic, making wide swaths of shelf area inhospitable to benthic life. In the oceans today such areas are called "Dead Zones" and they are increasing in number and extent due to the combined effects of man-made eutrophication and global warming. During the Early Jurassic, regional anoxic events developed in response to flood basalt volcanism, which triggered global warming, increased run-off, and changes in ocean circulation. The patchiness of Early Jurassic anoxia allows comparisons to be made with present-day "Dead Zones", while at the same time ocean de-oxygenation in the past may serve to predict future perturbations in the Earth system.

  9. The Triassic-Jurassic boundary in eastern North America

    NASA Technical Reports Server (NTRS)

    Olsen, P. E.; Comet, B.

    1988-01-01

    Rift basins of the Atlantic passive margin in eastern North America are filled with thousands of meters of continental rocks termed the Newark Supergroup which provide an unprecedented opportunity to examine the fine scale structure of the Triassic-Jurassic mass extinction in continental environments. Time control, vital to the understanding of the mechanisms behind mass extinctions, is provided by lake-level cycles apparently controlled by orbitally induced climate change allowing resolution at the less than 21,000 year level. Correlation with other provinces is provided by a developing high resolution magnetostratigraphy and palynologically-based biostratigraphy. A large number of at least local vertebrate and palynomorph extinctions are concentrated around the boundary with survivors constituting the earliest Jurassic assemblages, apparently without the introduction of new taxa. The palynofloral transition is marked by the dramatic elimination of a relatively high diversity Triassic pollen assemblage with the survivors making up a Jurassic assemblage of very low diversity overwhelmingly dominated by Corollina. Based principally on palynological correlations, the hypothesis that these continental taxonomic transitions were synchronous with the massive Triassic-Jurassic marine extinctions is strongly corroborated. An extremely rapid, perhaps catastrophic, taxonomic turnover at the Triassic-Jurassic boundary, synchronous in continental and marine realms is hypothesized and discussed.

  10. Lithofacies and sequence stratigraphic analysis of the Upper Jurassic siliciclastics in the eastern Kopet-Dagh Basin, NE Iran

    NASA Astrophysics Data System (ADS)

    Zand-Moghadam, Hamed; Moussavi-Harami, Reza; Mahboubi, Asadollah; Aghaei, Ali

    2016-05-01

    The Upper Jurassic (Oxfordian-Kimmeridgian) Mozduran Formation is the most important gas reservoirs of the northeast Iran. Siliciclastic facies of this formation in eastern most parts of the basin have not been studied yet. Therefore, four stratigraphic sections of Mozduran Formation have been selected in the Kole-Malekabad, Kale-Karab, Deraz-Ab and Karizak to interpret depositional history and analyze depositional sequences. Based on texture and sedimentary structures, 14 slilciclastic lithofacies were identified and classified into four categories, including conglomerate (Gms, Gp, Gt), sandstone (Sh, Sp, St, Sr, Sl, Sm, Se), mud rock (Fl) and intermediate sandstone-mud rock (Sr (Fl), Sr/Fl, Fl (Sr)). Identified lithofacies formed four architectural elements CH, SB, LA and FF. Lithofacies characteristics and architectural elements with mostly bimodal pattern of paleocurrents show that the majority of Mozduran lithofacies deposited in the coastal environment (tidal influence). Sequence stratigraphic analysis shows that the Kole-Malekabad section consists of two depositional sequences while other sections are characterized by three depositional sequences. The lower and upper sequence boundaries of the Mozduran Formation in all stratigraphic sections are SB1 that are distinguished by paleosol and sometime conglomerate horizons. Most of depositional sequences in studied sections are composed only of TST and HST. The TST deposits consist mostly of quartzarenite and litharenite petrofacies that have been deposited in the tidal zone. HST packages are mostly including mud rocks with interdeds of sandstone lithofacies that are deposited in supratidal setting. The LST facies is recognized only in the DS3 (equivalent to the second depositional sequences of the Kole-Malekabad), which consist of conglomerate facies. Instead, the Kole-Malekabad section is often composed of supratidal gypsiferrous shales, indicating sea level fall in the study area.

  11. Assessments of aquifer sensitivity on Navajo Nation and adjacent lands and ground-water vulnerability to pesticide contamination on the Navajo Indian Irrigation Project, Arizona, New Mexico, and Utah

    USGS Publications Warehouse

    Blanchard, Paul J.

    2002-01-01

    The U.S. Environmental Protection Agency requested that the Navajo Nation conduct an assessment of aquifer sensitivity on Navajo Nation lands and an assessment of ground-water vulnerability to pesticide contamination on the Navajo Indian Irrigation Project. Navajo Nation lands include about 17,000 square miles in northeastern Arizona, northwestern New Mexico, and southeastern Utah. The Navajo Indian Irrigation Project in northwestern New Mexico is the largest area of agriculture on the Navajo Nation. The Navajo Indian Irrigation Project began operation in 1976; presently (2001) about 62,000 acres are available for irrigated agriculture. Numerous pesticides have been used on the Navajo Indian Irrigation Project during its operation. Aquifer sensitivity is defined by the U.S. Environmental Protection Agency as 'The relative ease with which a contaminant [pesticide] applied on or near a land surface can migrate to the aquifer of interest. Aquifer sensitivity is a function of the intrinsic characteristics of the geologic material in question, any underlying saturated materials, and the overlying unsaturated zone. Sensitivity is not dependent on agronomic practices or pesticide characteristics.' Ground-water vulnerability is defined by the U.S. Environmental Protection Agency as 'The relative ease with which a contaminant [pesticide] applied on or near a land surface can migrate to the aquifer of interest under a given set of agronomic management practices, pesticide characteristics, and aquifer sensitivity conditions.' The results of the aquifer sensitivity assessment on Navajo Nation and adjacent lands indicated relative sensitivity within the boundaries of the study area. About 22 percent of the study area was not an area of recharge to bedrock aquifers or an area of unconsolidated deposits and was thus assessed to have an insignificant potential for contamination. About 72 percent of the Navajo Nation study area was assessed to be in the categories of most potential

  12. Harvestmen (Arachnida: Opiliones) from the Middle Jurassic of China

    NASA Astrophysics Data System (ADS)

    Huang, Diying; Selden, Paul A.; Dunlop, Jason A.

    2009-08-01

    Harvestmen (Arachnida: Opiliones) are familiar animals in most terrestrial habitats but are rare as fossils, with only a handful of species known from each of the Palaeozoic, Mesozoic, and Cenozoic eras. Fossil harvestmen from Middle Jurassic (ca. 165 Ma) strata of Daohugou, Inner Mongolia, China, are described as Mesobunus martensi gen. et sp. nov. and Daohugopilio sheari gen. et sp. nov.; the two genera differ primarily in the relative length of their legs and details of the pedipalps. Jurassic arachnids are extremely rare and these fossils represent the first Jurassic, and only the fourth Mesozoic, record of Opiliones. These remarkably well-preserved and modern-looking fossils are assigned to the Eupnoi, whereby M. martensi demonstrably belongs in Sclerosomatidae. It thus represents the oldest record of a modern harvestman family and implies a high degree of evolutionary stasis among one of the most widespread and abundant groups of long-legged, round-bodied harvestmen.

  13. Jurassic faults of southwest Alabama and offshore areas

    SciTech Connect

    Mink, R.M.; Tew, B.H.; Bearden, B.L.; Mancini, E.A. )

    1991-03-01

    Four fault groups affecting Jurassic strata occur in the southwest and offshore Alabama areas. They include the regional basement rift trend, the regional peripheral fault trend, the Mobile graben fault system, and the Lower Mobile Bay fault system. The regional basement system rift and regional peripheral fault trends are distinct and rim the inner margin of the eastern Gulf Coastal Plain. The regional basement rift trend is genetically related to the breakup of Pangea and the opening of the Gulf of Mexico in the Late Triassic-Early Jurassic. This fault trend is thought to have formed contemporaneously with deposition of Late Triassic-Early Jurassic Eagle Mills Formation and to displace pre-Mesozoic rocks. The regional peripheral fault trend consists of a group of en echelon extensional faults that are parallel or subparallel to regional strike of Gulf Coastal Plain strata and correspond to the approximate updip limit of thick Louann Salt. Nondiapiric salt features are associated with the trend and maximum structural development is exhibited in the Haynesville-Smackover section. No hydrocarbon accumulations have been documented in the pre-Jurassic strata of southwest and offshore Alabama. Productive hydrocarbon reservoirs occur in Jurassic strata along the trends of the fault groups, suggesting a significant relationship between structural development in the Jurassic and hydrocarbon accumulation. Hydrocarbon traps are generally structural or contain a major structural component and include salt anticlines, faulted salt anticlines, and extensional fault traps. All of the major hydrocarbon accumulations are associated with movement of the Louann Salt along the regional peripheral fault trend, the Mobile graben fault system, or the Lower Mobile Bay fault system.

  14. Constraints on Upper Jurassic palaeogeography in the Ula Gyda trend

    SciTech Connect

    Mundal, I.; Milton, N.; Robinson, N.

    1995-08-01

    BP Norway`s semi-regional 3D database in the Central Trough covers an area of nearly 3000 sq.km. around BP Norway`s two producing fields, Ula and Gyda, and includes strategic acreage within tie-back distance to the fields. Prospectivity in the Ula Gyda trend involves complex salt influenced structures and localized Upper Jurassic depositional systems. The objective of this paper is to demonstrate how the understanding of the semi-regional structures and salt tectonics helped constrain the interpretation of the Upper Jurassic palaeogeography. The control of basement structures (Permian) on cover structures (Upper Jurassic/Base Cretaceous) through Zechstein Salt was interpreted using the 3D semi-regional dataset. Analogue sandbox experiments from the Austin Geodynamics Laboratory provide support for the complex structures which were interpreted on the 3D seismic data. Sandbox models mimic the interpreted monoclinal drape of the Triassic and Jurassic section over the critical basin bounding fault in the Base Zechstein. Structural cells can be identified with the help of the salt isochore. The understanding of the relationship between structural development and salt distribution was a major control on the interpretation. This interpretation coupled with the Upper Jurassic reservoir distribution from well data provided the primary evidence for the gross depositional environment maps which were used in prospect evaluation in the area. 3D visualization and shaded relief displays of the interpreted horizons and isochores played a significant part in developing an understanding of the interplay between the deeper structures and the likely Upper Jurassic palaeogeography and depocentres.

  15. Suitability of Frigg, Åre, and Sognefjord Formation sandstones (North Sea) for storage of CO2

    NASA Astrophysics Data System (ADS)

    Saether, O. M.; Webb, J. C.; Wissing, B. W.; Bøe, R.

    2012-12-01

    The steady increase in concentration of CO2 in the atmosphere owing to the combustion of hydrocarbons is considered a major factor contributing to global warming. The storage of CO2 as subcritical gas in depleted oil and gas reservoirs and deep aquifers is considered a viable mitigation for reducing the impact of global temperature increase as a consequence of increased atmospheric CO2 (Hitcheon 1999, Bachu 2008). The volume of CO2 stored in the subsurface as supercritical liquid in any given sedimentary rock formation could be limited to <1% of the total pore space. Storage of larger volumes might lead to increased pressure and cause injection rates to undergo exponential decline (Ehlig-Economides and Economides 2010). Petrographic investigations of samples of sandstone from three quartz-rich sandstone formations in the Norwegian part of the North Sea, i.e. Tertiary Frigg Formation, Lower Jurassic Åre Formation, and Upper Jurassic Sognefjord Formation, reveal that all three sandstone formations exhibit features that favor suitability for CO2 storage. Favorable features include: 1) Abundant effective porosity 2) Stable mineralogy (i.e. abundant quartz) 3) Lack of chemically unstable detrital minerals (i.e. potassium and plagioclase feldspar, carbonates, volcanic rock fragments) 4) Lack of acid-soluble cements (e.g. iron-chlorite clay, siderite, calcite, or dolomite) 5) Lack of fresh-water sensitive (expansive) clay mineral cements (e.g. montmorillonite and mixed-layer illite-smectite (ML-IS). Intergranular porosity for each of the formations is estimated to be 28-31% of total rock volume for the Frigg Formation, 19-34% for the Åre Formation, and 16-29% for the Sognefjord Formation. Intergranular porosity of sandstones in each of the three formations is very well connected. Pore-throat radii of intergranular pores are interpreted to be significantly larger than 0.5 μm. Pore throats are not occluded by clay mineral cements, resulting in excellent estimated

  16. Transgressive-regressive cycles and Jurassic palaeogeography of northeast Iberia

    NASA Astrophysics Data System (ADS)

    Aurell, M.; Robles, S.; Bádenas, B.; Rosales, I.; Quesada, S.; Meléndez, G.; García-Ramos, J. C.

    2003-12-01

    A correlation and sequence stratigraphy study of Jurassic successions has been carried out in the main sedimentary basins of northeast Iberia, i.e., Asturias, Basque-Cantabrian, and Iberian basins, based on the identification of transgressive-regressive cycles. The development and palaeogeographic evolution of the epicontinental carbonate platforms of northeast Iberia were largely controlled by major tectonic activity at three main intervals, at the beginning of the Jurassic, in the Lower-Middle Jurassic transition, and during the uppermost Jurassic, respectively. During Early Jurassic times, northeast Iberia was the site of a single and large carbonate ramp opened to the north. This carbonate ramp suffered a progressive drowning, evolving from an inner to hemipelagic ramp systems, with the local development of suboxic environments in the deepest areas located to the north. During the Middle Jurassic, different open carbonate platforms were formed including the development of swells in intermediate areas. During the Upper Jurassic, the outer ramp areas were progressively moving to the east Iberian Basin, and the ammonite faunas showing a markedly Tethyan affinity thereafter. Three first order T-R cycles bounded by major discontinuities associated with significant time gaps are identified. They extend respectively from the latest Rhaetian to the Early Aalenian, from the Middle Aalenian to the Early Oxfordian and from the Early Oxfordian to the Late Berriasian. Major transgressive peaks occurred at the Middle Toarcian (Bifrons Zone), at the Late Bajocian (upper Niortense and Garantiana zones) and at the mid-Kimmeridgian (Divisum Zone). Each of the first order cycles includes four second-order T-R cycles. Cycles 1.1-1.4 are identified in the northern basins. Cycles 2.1-2.4 display some differences in age of transgressive peaks from one basin to another. Cycles 3.1-3.4 are mainly identified in the Iberian Basin. The correlation with other separated Boreal and

  17. The second Jurassic dinosaur rush and the dawn of dinomania.

    PubMed

    Brinkman, Paul D

    2010-09-01

    During the second Jurassic dinosaur rush museum paleontologists raced to display the world's first mounted sauropod dinosaur. The American Museum of Natural History triumphed in 1905 when its Brontosaurus debuted before an admiring crowd of wealthy New Yorkers. The Carnegie Museum of Natural History in Pittsburgh, the Field Columbian Museum in Chicago and other institutions were quick to follow with their own sauropod displays. Thereafter, dinomania spread far and wide, and big, showpiece dinosaurs became a museum staple. This brief but intensely competitive period of acquisitiveness fostered important Jurassic dinosaur revisions and crucial innovations in paleontological field and lab techniques. PMID:20667597

  18. Synkinematic quartz cementation in partially open fractures in sandstones

    NASA Astrophysics Data System (ADS)

    Ukar, Estibalitz; Laubach, Stephen E.; Fall, Andras; Eichhubl, Peter

    2014-05-01

    Faults and networks of naturally open fractures can provide open conduits for fluid flow, and may play a significant role in hydrocarbon recovery, hydrogeology, and CO2 sequestration. However, sandstone fracture systems are commonly infilled, at least to some degree, by quartz cement, which can stiffen and occlude fractures. Such cement deposits can systematically reduce the overall permeability enhancement due to open fractures (by reducing open fracture length) and result in permeability anisotropies. Thus, it is important to identify the factors that control the precipitation of quartz in fractures in order to identify potential fluid conduits under the present-day stress field. In many sandstones, quartz nucleates syntaxially on quartz grain or cement substrate of the fracture wall, and extends between fracture walls only locally, forming pillars or bridges. Scanning electron microscope cathodoluminescence (SEM-CL) images reveal that the core of these bridges are made up of bands of broken and resealed cement containing wall-parallel fluid inclusion planes. The fluid inclusion-rich core is usually surrounded by a layer of inclusion-poor clear quartz that comprises the lateral cement. Such crack-seal textures indicate that this phase was precipitating while the fractures were actively opening (synkinematic growth). Rapid quartz accumulation is generally believed to require temperatures of 80°C or more. Fluid inclusion thermometry and Raman spectroscopy of two-phase aqueous fluid-inclusions trapped in crack-seal bands may be used to track the P-T-X evolution of pore fluids during fracture opening and crack-seal cementation of quartz. Quartz cement bridges across opening mode fractures in the Cretaceous Travis Peak Formation of the tectonically quiescent East Texas Basin indicate individual fractures opened over a 48 m.y. time span at rates of 16-23 µm/m.y. Similarly, the Upper Cretaceous Mesaverde Group in the Piceance Basin, Colorado contains fractures that

  19. True triaxial testing of Castlegate sandstone.

    SciTech Connect

    Ingraham, M. D.; Holcomb, David Joseph; Issen, Kathleen A.

    2010-03-01

    Deformation bands in high porosity sandstone are an important geological feature for geologists and petroleum engineers; however, their formation is not fully understood. Axisymmetric compression, the common test for this material, is not sufficient to fully evaluate localization criteria. This study seeks to investigate the influence of the second principal stress on the failure and the formation of deformation bands in Castlegate sandstone. Experimental results from tests run in the axisymmetric compression stress state, as well as a stress state between axisymmetric compression and pure shear will be presented. Samples are tested using a custom triaxial testing rig at Sandia National Laboratories capable of applying stresses up to 400 MPa. Acoustic emissions are used to locate deformation bands should they not be visible on the specimen exterior. It is suspected that the second invariant of stress has a strong contribution to the failure mode and band formation. These results could have significant bearing on petroleum extraction as well as carbon dioxide sequestration.

  20. Preserving Native American petroglyphs on porous sandstone

    USGS Publications Warehouse

    Grisafe, D.A.

    1996-01-01

    A new method of chemical treatment is proposed to improve the durability of soft, porous sandstones onto which Native American petroglyphs have been carved. Cores of Dakota Sandstone from the Faris Cave site, located along the Smoky Hill River in Ellsworth County, Kansas, were treated with ethyl silicate dissolved in a lightweight ketone carrier, and some cores were subsequently treated with a combination of ethyl silicate and silane using the same solvent. Measurement of the resulting physical properties, when compared to untreated cores, indicate the treatments substantially increased the compressive strength and freeze-thaw resistance of the stone without discoloring the stone or completely sealing the pore system. The treatment increases the durability of the stone and provides a method for preserving the petroglyphs at the site. After treating test panels at the site, the petroglyphs were treated in like manner.

  1. Radionuclide transport in sandstones with WIPP brine

    SciTech Connect

    Weed, H.C.; Bazan, F.; Fontanilla, J.; Garrison, J.; Rego, J.; Winslow, A.M.

    1981-02-01

    Retardation factors (R) have been measured for the transport of /sup 3/H, /sup 95m/Tc, and /sup 85/Sr in WIPP brine using St. Peter, Berea, Kayenta, and San Felipe sandstone cores. If tritium is assumed to have R=1, /sup 95m/Tc has R=1.0 to 1.3 and therefore is essentially not retarded. Strontium-85 has R = 1.0 to 1.3 on St. Peter, Berea, and Kayenta, but R=3 on San Felipe. This is attributed to sorption on the matrix material of San Felipe, which has 45 volume % matrix compared with 1 to 10 volume % for the others. Retardation factors (R/sub s/) for /sup 85/Sr calculated from static sorption measurements are unity for all the sandstones. Therefore, the static and transport results for /sup 85/Sr disagree in the case of San Felipe, but agree for St. Peter, Berea, and Kayenta.

  2. Geological model of the Jurassic section in the State of Kuwait

    SciTech Connect

    Yousif, S.; Nouman, G.

    1995-11-01

    Until the end of the seventies, the knowledge of Jurassic Geology in the State of Kuwait was very limited, since only one deep well was drilled and bottomed in the Triassic sediments. Few scattered wells partially penetrated the Jurassic sequence. During the eighties, appreciable number of wells were drilled through the Jurassic, and added a remarkable volume of information. consequently it was necessary to analyze the new data, in order to try to construct a geological model for the Jurassic in the State of Kuwait. This paper includes a number of isopach maps explaining the Jurassic depositional basin which also helps in trying to explain the Jurassic basin in the Arabian Gulf basin. Structural evolution of the Jurassic sequence indicated an inversion of relief when compared with the Cretaceous sequence. In fact, the main Cretaceous arches were sites of sedimentation troughs during the Jurassic period. This fact marks a revolution in the concepts for the Jurassic oil exploration. One of the very effective methods of the definition of the Jurassic structures is the isopaching of the Gotnia Formation. Najmah, Sargelu and Marrat Formations include the main Jurassic reservoirs which were detected as a result of the exploration activities during the eighties. Selective stratigraphic and structural cross sections have been prepared to demonstrate and explain the nature of the Jurassic sediments.

  3. Effects of Coupled Structural and Diagenetic Processes on Deformation Localization and Fluid Flow Properties in Sandstone Reservoirs of the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Elliott, S. J.; Eichhubl, P.; Landry, C. J.

    2014-12-01

    Fluid flow tends to be restricted perpendicular to deformation bands through the combined effects of mechanical grain size reduction, porosity loss, and preferred cementation relative to the adjacent host rock. Deformation bands that occur in association with reservoir scale faults can impact reservoir-scale fluid flow and fault seal behavior, potentially imparting a permeability anisotropy to reservoir rocks. We use a combination of Hg-intrusion porosimetry, high-resolution 2D-image analysis of pore size distributions, and detailed compositional analyses obtained from integrating petrographic and SEM-based imaging techniques, including SEM-cathodoluminescence, backscattered electron imaging, and energy-dispersive X-ray spectroscopy, to (1) assess the effects of coupled chemical and mechanical processes leading to deformation localization within various detrital compositions [Cedar Mesa, Navajo, and Entrada sandstones] and (2) to quantify the effect of these processes on single and multiphase fluid flow as a function of host rock properties, structural position, and deformation band textural and diagenetic properties. Within each sample, bands of differing kinematic properties and structural style, i.e. shear bands, shear enhanced compaction bands etc., were identified and pre-kinematic pore-filling cements, as well as syn- and post-kinematic cements including various clay minerals, were distinguished for both the host rock and associated deformation bands. Although the deformation bands display a variety of textures and diagenetic attributes, initial petrophysical results suggest that the flow properties - permeability and capillary pressure curves - of the bands in the formations studied are very similar. However, both individual and clustered deformation bands of the Navajo Sandstone contain open or partially cemented cross-cutting fractures that could act as flow pathways across the deformation bands.

  4. Using the Sweat Lodge Ceremony as Group Therapy for Navajo Youth.

    ERIC Educational Resources Information Center

    Colmant, Stephen A.; Merta, Rod J.

    1999-01-01

    Describes the sweat lodge ceremony used at a residential treatment center located on the Navajo Nation and compares the ceremony to modern group work identifying Yalom's (1995) 11 therapeutic factors of group therapy within the ceremony. Considers widespread use of the ceremony with Native Americans and nonnative Americans as well as…

  5. Qualitative Study of the Use of Traditional Healing by Asthmatic Navajo Families

    ERIC Educational Resources Information Center

    Van Sickle, David; Morgan, Frank; Wright, Anne L.

    2003-01-01

    Despite increasing prevalence of asthma among American Indians and/or Alaska Natives, little is known about their use of traditional healing in its management. A convenience sample of 24 Navajo families with asthmatic members (n=35) was interviewed between June 1997 and September 1998. While 46% of families had previously used traditional healing,…

  6. SUSTAINABILITY OF MOUNTAIN SOURCES OF WATER FOR THE NAVAJO NATION UNDER THE IMPACT OF CLIMATE CHANGE

    EPA Science Inventory

    This model may assist Navajo communities to implement strategies that prepare the communities for impacts of climate change. Other tribes may be encouraged to develop similar hydrologic models to help understand the hydrologic responses of climate change in their area and h...

  7. Navajo Electrification for Sustainable Development: The Potential Economic and Social Benefits

    ERIC Educational Resources Information Center

    Ballentine, Crystal; DeSouza, Anil; Bain, Craig; Majure, Lisa; Smith, Dean Howard; Turek, Jill

    2004-01-01

    The concomitant secondary consequences of an electrification program and the potential long-term benefits of such a program are described. An electrification program can stimulate a move toward true self-determination and self-sufficiency for the Navajo nation.

  8. Observational studies as human experimentation: the uranium mining experience in the Navajo Nation (1947-66).

    PubMed

    Moure-Eraso, R

    1999-01-01

    This article evaluates how an observational epidemiologic study of federal agencies in uranium miners became an experiment of opportunity for radiation effects. Navajo miners and communities suffered environmental exposures caused by the practices of uranium mining and milling in the Navajo reservation during the 1947 to 1966 period. A historical review of the state-of-the-art knowledge of the health effects of uranium mining and milling during the years prior to 1947 was conducted. Contemporary prevention and remediation practices also were assessed. An appraisal of the summary of findings of a comprehensive evaluation of radiation human experimentation conducted by the U.S. federal government in 1995-96 (ACHRE) demonstrates that uranium miners, including Navajo miners, were the single group that was put more seriously at risk of harm from radiation exposures, with inadequate disclosure and often with fatal consequences. Uranium miners were unwilling and unaware victims of human experimentation to evaluate the health effects of radiation. The failure of the State and U.S. Governments to issue regulations or demand installation of known mine-dust exposure control measures caused widespread environmental damage in the Navajo Nation. PMID:17208792

  9. The Goal Wheel: Adapting Navajo Philosophy and the Medicine Wheel to Work with Adolescents

    ERIC Educational Resources Information Center

    Garner, Holly; Bruce, Mary Alice; Stellern, John

    2011-01-01

    The purpose of this article is to describe a group counseling model that is based on the indigenous medicine wheel as well as Navajo philosophy by which to help troubled adolescents restore harmony and balance in their lives, through establishing goals and sequential steps to accomplish these goals. The authors call this model the Goal Wheel. A…

  10. Maslow's Hierarchy of Needs and Navajo Students' Struggle for Self Esteem.

    ERIC Educational Resources Information Center

    Walker, Kay

    1996-01-01

    Maslow's theory of a hierarchy of needs is used to analyze Navajo youths' struggles for identity, fulfillment, and self-esteem. Answers to the challenges of substance abuse, violence, and gang membership are offered based upon George Bearden's eight-step plan, which stresses the importance of understanding human needs to perceive and transform…

  11. Instructor Reaction to Verbal and Nonverbal-Visual Styles: An Example of Navajo and Caucasian Children.

    ERIC Educational Resources Information Center

    Guilmet, George M.

    1979-01-01

    Holds that differences observed in instructor attention to Navajo and Caucasian children are due to the contrasting verbal and nonverbal-visual styles displayed by the two groups. Offers an evaluation program which attempts to offset teachers' tendencies to attend differentially to children displaying diverse behavioral styles in the classroom.…

  12. Navajo and Caucasian Children's Verbal and Nonverbal-Visual Behavior in the Urban Classroom

    ERIC Educational Resources Information Center

    Guilmet, George M.

    1978-01-01

    A formal observation technique was used in an urban classroom context to assess the verbal and nonverbal-visual behavior of 17 Navajo and 7 Caucasian children. Two statistical techniques revealed significant intergroup differences in verbal and nonverbal-visual style. ( Author)

  13. Classroom Resiliency--A Comparison of Navajo Elementary Students' Perceptions of Their Classroom Environment

    ERIC Educational Resources Information Center

    Piechowski, Alta Begay

    2011-01-01

    The purpose of this study was to determine if there was a gender difference in how students perceived their classroom environment on the Navajo Nation public school. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be…

  14. "He Said It All in Navajo!": Indigenous Language Immersion in Early Childhood Classrooms

    ERIC Educational Resources Information Center

    Lockard, Louise; De Groat, Jennie

    2010-01-01

    This paper describes the historical and social foundations of the Navajo Headstart Immersion program. The researchers have worked as teachers, teacher educators, and parents in these programs. They reflect on the need for new partnerships among tribes, tribal colleges and universities to prepare teachers and to develop curriculum materials for…

  15. The Navajo Learning Network and the NASA Life Sciences/AFOSR Infrastructure Development Project

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The NSF-funded Navajo Learning Network project, with help from NASA Life Sciences and AFOSR, enabled Dine College to take a giant leap forward technologically - in a way that could never had been possible had these projects been managed separately. The combination of these and other efforts created a network of over 500 computers located at ten sites across the Navajo reservation. Additionally, the college was able to install a modern telephone system which shares network data, and purchase a new higher education management system. The NASA Life Sciences funds further allowed the college library system to go online and become available to the entire campus community. NSF, NASA and AFOSR are committed to improving minority access to higher education opportunities and promoting faculty development and undergraduate research through infrastructure support and development. This project has begun to address critical inequalities in access to science, mathematics, engineering and technology for Navajo students and educators. As a result, Navajo K-12 education has been bolstered and Dine College will therefore better prepare students to transfer successfully to four-year institutions. Due to the integration of the NSF and NASA/AFOSR components of the project, a unified project report is appropriate.

  16. Educational and Institutional Services Available to Navajo and Hopi People: Observations of Student Teachers.

    ERIC Educational Resources Information Center

    Mahan, James M.

    The personal, evaluative statements of student teachers were used to study the perceptions of newcomers to American Indian schools and communities. Respondents in this study were 90 Anglo preservice teachers from 10 universities, completing the final 17 weeks of their teacher preparation programs as full-time student teachers in Navajo and Hopi…

  17. Navajo County Community College District; Its History, Its Future, 1961-1985.

    ERIC Educational Resources Information Center

    Northland Pioneer Coll., Holbrook, AZ.

    This document presents an overview of the history and characteristics of Northland Pioneer College (NPC), established in 1974 to serve Navajo County, a rural, sparsely populated area in northeastern Arizona (70 percent Indian Reservation land). The information presented in this document is intended to be of assistance in future planning for NPC.…

  18. The Economic Contributions of Women in a Rural Western Navajo Community.

    ERIC Educational Resources Information Center

    Russell, Scott C.; McDonald, Mark B.

    1982-01-01

    Examines and enumerates economic changes that have occurred in the traditional rural Navajo community of Shonto. While women's net income contributions to Shonto's economy has declined, their position has seen only a slight erosion; their activities (sheep and goat husbandry, agriculture, arts and crafts) are still considered necessary and…

  19. Improving residential coal stoves: Air quality issues on the Navajo Reservation and the implications for China

    SciTech Connect

    Goff, S.J.; Hickmott, D.D.; Brown, L.F.; Currier, R.P.; Thayer, G.R.; Semken, S.C.; Lameman, T.; Martin, S.; Yazzie, S.

    1997-12-31

    This is a report of a one-year, Laboratory-Directed Research and Development (LDRD) program development (PD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to evaluate the environmental impacts of home-scale coal combustion on the Navajo Reservation and develop strategies to reduce adverse health effects associated with home-scale coal combustion. Principal accomplishments of this project were: (1) determination of the metal and gaseous emissions of a representative stove on the Navajo Reservation; (2) recognition of cyclic gaseous emissions in combustion in home-scale combustors; (3) back of the envelope calculation that home-scale coal combustion may impact Navajo health; and (4) identification that improved coal stoves require the ability to burn diverse feedstocks (coal, wood, biomass). Ultimately the results of Navajo home-scale coal combustion studies will be extended to the Developing World, particularly China, where a significant number (> 150 million) of households continue to utilize low-grade coal in their homes.

  20. Learn in Beauty: A Professional Development Project for Navajo Bilingual Teachers.

    ERIC Educational Resources Information Center

    Lockard, Louise; de Groat, Jennie; Bedonie, Clara

    The Learn in Beauty Project at Northern Arizona University worked with a consortium of seven Navajo Nation school districts seeking to implement the Dine Language and Culture teaching perspective. This perspective is based on the premises that education is best when it reflects a sense of place; education should be based on the philosophy and…

  1. Secondary Transition of Multicultural Learners: Lessons from the Navajo Native American Experience.

    ERIC Educational Resources Information Center

    Wilder, Lynn K.; Jackson, Aaron P.; Smith, Timothy B.

    2001-01-01

    This discussion of the impact of culture and cultural differences on school and work and the importance of enhancing multicultural awareness also reports on a study that evaluated the experience of 22 Navajo Native Americans high school graduates in transition. Findings stress the importance of students' significant relationships, limited…

  2. From Break Dancing to Heavy Metal: Navajo Youth, Resistance, and Identity.

    ERIC Educational Resources Information Center

    Deyhle, Donna

    1998-01-01

    Research on Navajo youth lives and choices examines the messages conveyed through their breakdancing and heavy-metal music. Central to the messages is resistance to assimilation into mainstream culture and maintenance of their cultural identity in a racially divided community. (MMU)

  3. 75 FR 16174 - Renewal of Agency Information Collection for Navajo Partitioned Lands Grazing Permits; Request...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ... collection of information was published on February 24, 2010 (75 FR 8731). No comments were received. This... collection is currently authorized by OMB Control Number 1076-0162, which expires March 31, 2010. The... collection activity. III. Data OMB Control Number: 1076-0162. Title: Navajo Partitioned Lands Grazing...

  4. 40 CFR 49.5512 - Federal Implementation Plan Provisions for Four Corners Power Plant, Navajo Nation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Federal Implementation Plan Provisions for Four Corners Power Plant, Navajo Nation. 49.5512 Section 49.5512 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE INDIAN COUNTRY: AIR QUALITY PLANNING AND MANAGEMENT Implementation Plans...

  5. 40 CFR 49.5512 - Federal Implementation Plan Provisions for Four Corners Power Plant, Navajo Nation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Federal Implementation Plan Provisions for Four Corners Power Plant, Navajo Nation. 49.5512 Section 49.5512 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE INDIAN COUNTRY: AIR QUALITY PLANNING AND MANAGEMENT Implementation Plans...

  6. 25 CFR 161.101 - How will tribal laws be enforced on the Navajo Partitioned Lands?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... testimony set forth at 43 CFR part 2, subpart E; (ii) Constitute a waiver of the sovereign immunity of the... 25 CFR, so long as the new waiver does not violate a federal statute or judicial decision or conflict... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws Pertaining to...

  7. 25 CFR 161.101 - How will tribal laws be enforced on the Navajo Partitioned Lands?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... testimony set forth at 43 CFR part 2, subpart E; (ii) Constitute a waiver of the sovereign immunity of the... 25 CFR, so long as the new waiver does not violate a federal statute or judicial decision or conflict... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws Pertaining to...

  8. 25 CFR 161.101 - How will tribal laws be enforced on the Navajo Partitioned Lands?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... testimony set forth at 43 CFR part 2, subpart E; (ii) Constitute a waiver of the sovereign immunity of the... 25 CFR, so long as the new waiver does not violate a federal statute or judicial decision or conflict... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws Pertaining to Permits §...

  9. 25 CFR 161.101 - How will tribal laws be enforced on the Navajo Partitioned Lands?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... testimony set forth at 43 CFR part 2, subpart E; (ii) Constitute a waiver of the sovereign immunity of the... 25 CFR, so long as the new waiver does not violate a federal statute or judicial decision or conflict... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Tribal Policies and Laws Pertaining to...

  10. The Disjunct Boundary in the Navajo and Tanaina Verb Prefix Complexes

    ERIC Educational Resources Information Center

    Kari, James

    1975-01-01

    This article discusses Athapascan verb morphology. It is shown that a word-internal boundary before the direct object position in a verb prefix complex plays a significant role in the phonology of two geographically distant languages, Navajo and Tanaina. (CLK)

  11. Ladies, Livestock, Land and Lucre: Women's Networks and Social Status on the Western Navajo Reservation.

    ERIC Educational Resources Information Center

    Conte, Christine

    1982-01-01

    Explores the role of Navajo women in a remote area of the western reservation in the processes of production, consumption, and distribution of resources. Emphasis is placed on the way women selectively activate kin ties in order to perform tasks, obtain resources, and accumulate wealth. (Author)

  12. Increasing the Number of Latino and Navajo Teachers in Hard-to-Staff Schools.

    ERIC Educational Resources Information Center

    Becket, Diane R.

    1998-01-01

    Examined the development of two teacher education programs designed to increase the number of quality minority teachers in Latino neighborhood schools and on the Navajo reservation. Review of teacher education literature and analysis of interviews with program staff, archival records, and program documentation indicated that these two…

  13. The Navajo Environmental Protection Commission: Developing the Capabilities for Environmental Impact Assessment and Regulation

    ERIC Educational Resources Information Center

    Cortner, Hanna J.

    1976-01-01

    To develop effective/efficient environmental impact assessment and regulatory capabilities, the Navajo Environmental Protection Commission will need to commit more of its limited resources to building the political support which will exert real influence at the pre-commitment stages of development decision making. (JC)

  14. Of Mother Earth and Father Sky: A Photographic Study of Navajo Culture.

    ERIC Educational Resources Information Center

    McCarty, T. L.; And Others

    Utilizing 52 black and white photographs, the book tells a story about the Navajo people, their hopes and problems, the strategies they have adopted to cope with the problems, their interactions with each other and with the land, and their feelings about the land which provides a basis for their livelihood. Part of a series of curriculum materials…

  15. Native American Navajo Teenage Parenting Women, Cross-Generational Support and Implications for Policy.

    ERIC Educational Resources Information Center

    Dalla, Rochelle L.; Gamble, Wendy C.

    This study examined teenage parenting among Native Americans, focusing on the support received from grandmothers. The sample was comprised of 15 subjects living on a Navajo reservation: 8 adolescent mothers between 16 to 19 years--most with one child and enrolled either in high school or in an alternative education program; and seven women…

  16. Methods and Resources for the Construction and Maintenance of a Navajo Population Register.

    ERIC Educational Resources Information Center

    Kelly, William H.

    The most feasible method for constructing a Navajo population register was to produce a preliminary register from data contained in existing records and to perfect and extend this register either through subsequent clerical and record-accumulating operations, the existing school census operation, a special program of field enumeration, or a…

  17. An Analysis of Community-School Relations in One Suburban and Four Navajo School Districts.

    ERIC Educational Resources Information Center

    Witherspoon, Gary Jay

    The primary concern of this research was with community-school relations in American Indian education, particularly Navajo education. Major data on which this study was based came from interviews with 223 parents whose children attended various types of schools in Arizona during 1967-68: Nazlini (Bureau of Indian Affairs), Many Farms (BIA and…

  18. Goal Theory and Indigenous Minority School Motivation: Relevance and Application. Australian Aboriginal and Navajo Indian Research.

    ERIC Educational Resources Information Center

    McInerney, Dennis M.

    This paper reports on a continuing study of Australian Aboriginal and Navajo Indian children. The study investigates the relevance and applicability of goal theory to explaining indigenous minority motivation in school settings. Task, ego social solidarity, and extrinsic goal structures were examined as a means of explaining and predicting…

  19. Isotopic fractionation of uranium in sandstone

    USGS Publications Warehouse

    Rosholt, J.N.; Shields, W.R.; Garner, E.L.

    1963-01-01

    Relatively unoxidized black uranium ores from sandstone deposits in the western United States show deviations in the uranium-235 to uranium-234 ratio throughout a range from 40 percent excess uranium-234 to 40 percent deficient uranium-234 with respect to a reference uranium-235 to uranium-234 ratio. The deficient uranium-234 is leached preferentially to uranium-238 and the excess uranium-234 is believed to result from deposition of uranium-234 enriched in solutions from leached deposits.

  20. Stratigraphic and structural configuration of the Navajo (Jurassic) through Ouray (Mississippian-Devonian) formations in the vicinity of Davis and Lavender Canyons, southeastern Utah

    SciTech Connect

    McCleary, J.R.; Romie, J.E.

    1986-04-01

    This study developed a three-dimensional computer model of stratigraphic and structural relationships within a 3497-km/sup 2/ (1350-mi/sup 2/) study area centered on the proposed site for a high-level nuclear waste repository in southeastern Utah. The model consists of a sequence of internally reconciled isopach and structure contour maps horizontally registered and stored in stratigraphic order. This model can be used to display cross sections, perspective block diagrams, or fence diagrams at any orientation; estimate depth of formation contacts and thicknesses for any new stratigraphic or hydrologic boreholes; facilitate ground-water modeling studies; and evaluate the structural and stratigraphic evolution of the study area. This study also includes limited evaluations of aquifer continuity in the Elephant Canyon and Honaker Trail Formations, and of salt dissolution and flowage features as interpreted from geophysical logs. The study identified a long history of movement in the fault system in the north-central part of the study area and a major salt flowage feature in the northeastern part. It describes the Elephant Canyon Formation aquifer as laterally limited, the Honaker Trail Formation aquifer as fairly continuous over the area, and Beef Basin in the southern part of the area as a probable dissolution feature. It also concludes that the Shay-Bridger Jack-Salt Creek Graben system is apparently a vertically continuous feature between the basement and ground surface. No stratigraphic or structural discontinuities were detected in the vicinity of Davis Canyon that appear to be detrimental to the siting of a waste repository.

  1. Dynamic optimization model of energy related economic planning and development for the Navajo nation

    SciTech Connect

    Beladi, S.A.

    1983-01-01

    The Navajo reservation located in portions of Arizona, New Mexico and Utah is rich in low sulfur coal deposits, ideal for strip mining operation. The Navajo Nation has been leasing the mineral resources to non-Indian enterprises for purposes of extraction. Since the early 1950s the Navajo Nation has entered into extensive coal leases with several large companies and utilities. Contracts have committed huge quantities of Navajo coal for mining. This research was directed to evaluate the shadow prices of Navajo coal and identify optimal coal extraction. An economic model of coal resource extraction over time was structured within an optimal control theory framework. The control problem was formulated as a discrete dynamic optimization problem. A comparison of the shadow prices of coal deposits derived from the dynamic model with the royalty payments the tribe receives on the basis of the present long-term lease contracts indicates that, in most cases, the tribe is paid considerably less than the amount of royalty projected by the model. Part of these discrepancies may be explained in terms of the low coal demand condition at the time of leasing and due to greater uncertainties with respect to the geologic information and other risks associated with mining operations. However, changes in the demand for coal with rigidly fixed terms of royalty rates will lead to non-optimal extraction of coal. A corrective tax scheme is suggested on the basis of the results of this research. The proposed tax per unit of coal shipped from a site is the difference between the shadow price and the present royalty rate. The estimated tax rates over time are derived.

  2. Quantifying the Texture, Composition, and Coupled Chemical-Mechanical Diagenesis of Deformation Bands within Sandstone Reservoir Outcrop Analogs of Assorted Detrital Compositions, Southwestern USA

    NASA Astrophysics Data System (ADS)

    Elliott, S. J.; Eichhubl, P.

    2015-12-01

    In porous sandstones many factors including grain size, sorting, stress-state, and composition influence deformation mechanisms and resulting deformation band properties, especially those related to fluid flow. Using high resolution SEM-CL, EDS, and BSE images we quantitatively point counted various band types and their associated host rocks at the sub-micron scale, performed comprehensive grain size analyses on the undeformed host rocks, and calculated the total porosity lost through coupled chemical-mechanical means for each host rock and band. Our goals were to 1) determine the influence of detrital composition and texture [Cedar Mesa, Navajo, and Entrada sandstones] both on bands formed by different mechanisms and on bands formed by the same deformation mechanism at various stages of development, and to 2) assess the effects of coupled chemical-mechanical processes leading to deformation localization within these sandstone reservoir outcrop analogs. Analyzed samples include a non-cataclastic disaggregation band, a non-cataclastic pressure solution band, and single, multistrand, and clustered cataclastic bands, all of which formed through combinations of grain reorganization, brittle processes, pressure solution, and cementation. The textural, compositional, and diagenetic properties of the older burial-related bands (pressure solution and disaggregation) are more comparable to the detrital host rocks than the later, faulting-related cataclastic bands, regardless of the host rock characteristics. Furthermore, the relative influence of the detrital sandstone properties varies throughout the evolutionary stages of cataclastic band development. For example, multistrand bands across formations have undergone similar chemical-mechanical deformation, yet their remnant porosities and compositions vary drastically. Cluster bands, on the other hand, represent a later developmental stage than multistrand bands, and yet their porosities and compositions are similar across

  3. A Model of Evolution of Fault Structure in Porous Sandstone Reflecting the Effect of Geometric Irregularities Associated with Early-Formed Segment Linkages

    NASA Astrophysics Data System (ADS)

    Schafer, K. W.; Johnson, B.

    2001-12-01

    We propose a model of the early evolution of the structure of strike-slip faults in porous sandstone based upon detailed maps of faults with small displacements (mm to decimeters) in the Hickory Sandstone in central Texas and the Navajo Sandstone near Moab, UT. We assume faults at a given site follow similar evolutionary paths and infer relative timing of formation of fault elements using cross cutting and high-angle abutment relationships. Faults consist of a network of hard-linked smaller segments. The number of fault segments varies along a fault and qualitatively become more numerous and preferentially clustered with increasing displacement. Lacunarity analyses and variograms of spatial density of fault segments quantitatively document the clustering of fault segments. Consistent with earlier work, we infer that faults evolve in the initial stage by linkage of an early-formed array of en echelon small faults that typically step opposite to the sense of shear. Linkage is by one of two geometrically and kinematically distinct linkage structures. With increasing fault displacement, new fault segments are preferentially added in close proximity to or within the early linkages. Accreted segments typically are arcuate and abut earlier segments at a high angle. Consequently, the spatial density of fault segments varies episodically along the fault. Early linkage structures represent geometric irregularities (roughness) along the evolving fault that we interpret to result in geometric stress concentrations that preferentially localize formation of new fault segments. This conceptual model does not demand the commonly assumed strain-hardening of the gouge of individual fault segments in order to explain the evolving complexity of fault structure with increasing displacement. The lack of an implied strain-hardening behavior is consistent with laboratory-scale fault development in porous sandstone.

  4. Apatite Fission-Track Analysis of the Middle Jurassic Todos Santos Formation from Chiapas, Mexico.

    NASA Astrophysics Data System (ADS)

    Abdullin, Fanis; Solé, Jesús; Shchepetilnikova, Valentina; Solari, Luigi; Ortega-Obregón, Carlos

    2014-05-01

    The Sierra de Chiapas (SCH), located in the south of Mexico, is a complex geological province that can be divided on four different lithological or tectonic areas: (1) the Chiapas Massif Complex (CMC); (2) the Central Depression; (3) the Strike-slip Fault Province, and (4) the Chiapas Fold-and-thrust Belt. The CMC mostly consists of Permian granitoids and meta-granitoids, and represents the basement of the SCH. During the Jurassic period red beds and salt were deposited on this territory, related to the main pulse of rifting and opening of the Gulf of Mexico. Most of the Cretaceous stratigraphy contains limestones and dolomites deposited on a marine platform setting during the postrift stage of the Gulf of Mexico rift. During the Cenozoic Era took place the major clastic sedimentation along the SCH. According the published low-temperature geochronology data (Witt et al., 2012), SCH has three main phases of thermo-tectonic history: (1) slow exhumation between 35 and 25 Ma, that affected mainly the basement (CMC) and is probably related to the migration of the Chortís block; (2) fast exhumation during the Middle-Late Miocene caused by strike-slip deformation that affects almost all Chiapas territory; (3) period of rapid cooling from 6 to 5 Ma, that affects the Chiapas Fold-and-thrust Belt, coincident with the landward migration of the Caribbean-North America plate boundaries. The two last events were the most significant on the formation of the present-day topography of the SCH. However, the stratigraphy of the SCH shows traces of the existence of earlier tectonic events. This study presents preliminary results of apatite fission-track (AFT) dating of sandstones from the Todos Santos Formation (Middle Jurassic). The analyses are performed with in situ uranium determination using LA-ICP-MS (e.g., Hasebe et al., 2004). The AFT data indicate that this Formation has suffered high-grade diagenesis (probably over 150 ºC) and the obtained cooling ages, about 70-60 Ma

  5. Stratigraphy of the Jurassic system in northern Egypt

    SciTech Connect

    Keeley, M.L.; Shaw, D.; Forbes, G.A.

    1988-08-01

    A regional synthesis is presented of the stratigraphy of Jurassic strata in Egypt north of 30/degree/N, based on the study of about 80 wells and outcrops from northeastern Egypt. Almost all fossil groups have been investigated for biostratigraphic control. Published work on ammonite faunas from Gebel el Maghara (north Sinai) is integrated with extensive original work on palynofloras (and, to a lesser extent, ostracod/foraminiferal faunas) recovered from marine rocks in the subsurface. The recovery of rich dinocyst assemblages enables the recognition of a ten-fold zonation scheme, largely within the Middle-Late Jurassic sedimentary package. The upper limit of this package is marked by the Cimmerian erosional event; strata younger than Oxfordian are rarely preserved. Only east of 30/degree/E is significant sedimentation known to have occurred immediately prior to the major early Bajocian transgressive event. Thereafter mean sea level rose steadily. The Lower Triassic-Lower Jurassic sedimentary package is poorly understood, largely the result of scanty and ambiguous stratigraphic evidence. However, regional correlations suggest that only very thin earliest Jurassic (Hettangian ) clastic deposition succeeded a sequence of Upper Triassic carbonates and evaporites (Wadi en Natrun Formation) in the north. Arising from these studies is a standard lithostratigraphical scheme. The upper sedimentary package, the Gebel el Maghara Group, comprises three formations (Masajid, Khatatba, and Inmar) and seven members; new units are defined and old units redefined.

  6. Evidence for a Mid-Jurassic Adaptive Radiation in Mammals.

    PubMed

    Close, Roger A; Friedman, Matt; Lloyd, Graeme T; Benson, Roger B J

    2015-08-17

    A series of spectacular discoveries have transformed our understanding of Mesozoic mammals in recent years. These finds reveal hitherto-unsuspected ecomorphological diversity that suggests that mammals experienced a major adaptive radiation during the Middle to Late Jurassic. Patterns of mammalian macroevolution must be reinterpreted in light of these new discoveries, but only taxonomic diversity and limited aspects of morphological disparity have been quantified. We assess rates of morphological evolution and temporal patterns of disparity using large datasets of discrete characters. Rates of morphological evolution were significantly elevated prior to the Late Jurassic, with a pronounced peak occurring during the Early to Middle Jurassic. This intense burst of phenotypic innovation coincided with a stepwise increase in apparent long-term standing diversity and the attainment of maximum disparity, supporting a "short-fuse" model of early mammalian diversification. Rates then declined sharply, and remained significantly low until the end of the Mesozoic, even among therians. This supports the "long-fuse" model of diversification in Mesozoic therians. Our findings demonstrate that sustained morphological innovation in Triassic stem-group mammals culminated in a global adaptive radiation of crown-group members during the Early to Middle Jurassic. PMID:26190074

  7. Jurassic Park as a Teaching Tool in the Chemistry Classroom.

    ERIC Educational Resources Information Center

    Jollis, W. Gary, Jr.

    1996-01-01

    Describes how the science fiction novel "Jurassic Park" has been used to provide the focus for summate discussions among gifted high school students participating in a state-sponsored, science-intensive summer program. Discusses adaptations of this approach for use in chemistry classes from the high school to intermediate college level. (JRH)

  8. Jurassic Management: Chaos and Management Development in Educational Institutions.

    ERIC Educational Resources Information Center

    Gunter, Helen

    1995-01-01

    Investigates the failure of "Jurassic" management: visioning, consensus value systems, proactively created teams, and development planning. Applied chaos theory can help self-managing schools and colleges avoid disaster and improve their management-development programs. Survival in turbulent times is based on educational managers' capacity to make…

  9. Jurassic deposits of the southern part of the Irkutsk sedimentary basin

    NASA Astrophysics Data System (ADS)

    Akulov, N. I.; Frolov, A. O.; Mashchuk, I. M.; Akulova, V. V.

    2015-07-01

    This work presents new data on the lithology, paleontology, stratigraphy, and correlation of Jurassic deposits of the Irkutsk coal-bearing basin. According to the detailed analysis of the lithology and paleontology of the reference sections, the Jurassic deposits of the southern part of this basin are subdivided into four formations: Baikal'skaya, Dabatskaya, Cheremkhovskaya, and Prisayanskaya. The Lower Jurassic coarse deposits of the Baikal'skaya Formation are regarded as the most ancient; the Middle Jurassic deposits of the Prisayanskaya Formation are the youngest. The industrial coal-bearing deposits of the Cheremkhovskaya Formation formed in the Early Jurassic, from the Pliensbachian to Toarcian.

  10. Hydrocarbon potential of a new Jurassic play, central Tunisia

    SciTech Connect

    Beall, A.O. ); Law, C.W. )

    1996-01-01

    A largely unrecognized Jurassic Sag Basin has been identified in central Tunisia, proximal to the Permo-Carboniferous flexure delineating the northern boundary of the Saharan platform of north Africa. The northwestern margin of the Sag is delineated by an extensive region of salt-cored anticlines and localized salt diapirs extending north and west. Due to lack of deep drilling, delineation of the Sag is largely based on regional gravity data. Subsidence of the Jurassic Sag Basin is characterized by rapid expansion of Jurassic sediments from 400 m. of tidal flat and shelf carbonate at the western outcrop to over 2000 meters of tidal flat and basinal carbonate and shale within the basin center, a five-fold expansion. Rapid loading of the basin continued into Lower Cretaceous time, marked by lateral flowage of Triassic salt into pronounced structural trends. Published source rock data and interpreted subsurface well data provided the basis for GENEX 1-D hydrocarbon generation and expulsion modeling of the Sag. Middle Jurassic black source shales typically contain Type II and Type III kerogens with T.O.C.'s ranging up to 4 percent. Modeling results indicate that middle Jurassic shales are presently mature for liquid generation within portions of the Sag, with maximum generation taking place during the Tertiary. Potential hydrocarbon generation yields, based on 60 meters of mature source shale, are 20,000 BOE/acre for gas and 75,000 BOE/acre for liquids. Prospects within the region could contain an estimated potential reserve of several T.C.F. or over 1 billion barrels of oil.

  11. Hydrocarbon potential of a new Jurassic play, central Tunisia

    SciTech Connect

    Beall, A.O.; Law, C.W.

    1996-12-31

    A largely unrecognized Jurassic Sag Basin has been identified in central Tunisia, proximal to the Permo-Carboniferous flexure delineating the northern boundary of the Saharan platform of north Africa. The northwestern margin of the Sag is delineated by an extensive region of salt-cored anticlines and localized salt diapirs extending north and west. Due to lack of deep drilling, delineation of the Sag is largely based on regional gravity data. Subsidence of the Jurassic Sag Basin is characterized by rapid expansion of Jurassic sediments from 400 m. of tidal flat and shelf carbonate at the western outcrop to over 2000 meters of tidal flat and basinal carbonate and shale within the basin center, a five-fold expansion. Rapid loading of the basin continued into Lower Cretaceous time, marked by lateral flowage of Triassic salt into pronounced structural trends. Published source rock data and interpreted subsurface well data provided the basis for GENEX 1-D hydrocarbon generation and expulsion modeling of the Sag. Middle Jurassic black source shales typically contain Type II and Type III kerogens with T.O.C.`s ranging up to 4 percent. Modeling results indicate that middle Jurassic shales are presently mature for liquid generation within portions of the Sag, with maximum generation taking place during the Tertiary. Potential hydrocarbon generation yields, based on 60 meters of mature source shale, are 20,000 BOE/acre for gas and 75,000 BOE/acre for liquids. Prospects within the region could contain an estimated potential reserve of several T.C.F. or over 1 billion barrels of oil.

  12. Geology and diagenetic history of overpressured sandstone reservoirs, Venture Gas field, offshore Nova Scotia, Canada

    SciTech Connect

    Jansa, L.F. Dalhousie Univ., Halifax, Nova Scotia ); Urrea V.H.N. )

    1990-10-01

    Deep exploratory wells in the Scotian Basin, offshore Nova Scotia, Canada, have encountered overpressured formations with pressures 1.9 {times} the normal hydrostatic gradient. The overpressures occur over an area of approximately 10,000 km{sup 2}. In the Venture field, the abnormal pressures are confined below a depth of 4,500 m and are associated with Upper Jurassic-Lower Cretaceous gas- and condensate-bearing sandstone reservoirs. The overpressures occur within normally compacted shales containing numerous overpressured sandstone reservoir beds. The development of overpressures, seals, and secondary reservoirs are all diagenetically driven. Three secondary porosity depth levels, which top at 2,500 m (65C), 3,700 m (95C), and 4,600 m (130C), correlate with major steps in the organic matter maturation in the basin. Secondary porosity is initially achieved by aluminosilicate dissolution, with ferroan sparry calcite cement dissolution dominating below 4,000 m. Porosity enhancement and preservation is not the result of a single diagenetic event but instead the result of a series of diagenetic events that overlapped in time. Formation of dynamic diagenetic barriers within the zone of peak gas generation helps retard the diffusive migration of hydrocarbons and other fluids expelled during shale diagenesis resulting in pressure build up. The preservation of up to 32% porosity under 500-1,000 atm of pressure could not be achieved without simultaneous pressuring of developing voids. Significant for hydrocarbon exploration is that Venture-type diagenetic overpressures are not associated with undercompacted sediments and, hence, they cannot be predicted from compaction trends during drilling. Petrographic diagenetic, and lithofacies studies can be instrumental in predicting potential areas of deep subsurface secondary reservoirs dependent.

  13. Benthic aquatic ecosystems across the Permian-Triassic transition: record from biogenic structures in fluvial sandstones, central Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    Miller, M. F.

    2000-07-01

    The effect of the Permian extinction in communities inhabiting sandy stream bottoms can be evaluated using trace fossils as proxies for body fossils. Permian and Triassic sandstones exposed in the Beardmore and Shackleton Glacier areas (central Transantarctic Mountains) were deposited in sandy braided streams and contain four types of trace fossils (vertical shafts and horizontal, bilobed and chevron traces). These traces were produced by a single type of animal that moved in the top 30 cm of sediment and dominated the benthic community. Evidence for a single producer includes similar size (diameter) of all traces and change within single specimens from one trace type to another. The animal was not affected by the Permian extinction event, as evidenced by its equal abundance within the Permian (Buckley Formation) and Triassic (Fremouw Formation) fluvial sandstones in the Beardmore Glacier area. Based on trace morphology and on domination of modern sandy river ecosystems by insects, the producer most likely was an insect, although its more precise identity is problematic. Although families of insects with modern aquatic burrowers are not known before the Jurassic, these trace fossils may show that these burrowers were present earlier than the insect body-fossil record suggests. Alternatively, archaic insect groups, many of which became extinct at the end-Permian and are known to have been aquatic but not infaunal, may have included some active burrowers that were unscathed by the Permian extinction.

  14. A new pterosaur tracksite from the jurassic summerville formation, near Ferron, Utah

    USGS Publications Warehouse

    Mickelson, D.L.; Lockley, M.G.; Bishop, J.; Kirkland, J.

    2003-01-01

    Pterosaur tracks (cf. Pteraichnus) from the Summerville Formation of the Ferron area of central Utah add to the growing record of Pteraichnus tracksites in the Late Jurassic Summerville Formation and time-equivalent, or near time-equivalent, deposits. The site is typical in revealing high pterosaur track densities, but low ichnodiversity suggesting congregations or "flocks" of many individuals. Footprint length varies from 2.0 to 7.0 cms. The ratio of well-preserved pes:manus tracks is about 1:3.4. This reflects a bias in favor of preservation of manus tracks due to the greater weight-bearing role of the front limbs, as noted in other pterosaur track assemblages. The sample also reveals a number of well-preserved trackways including one suggestive of pes-only progression that might be associated with take off or landing, and another that shows pronounced lengthening of stride indicating acceleration. One well-preserved medium-sized theropod trackway (Therangospodus) and other larger theropod track casts (cf. Megalosauripus) are associated with what otherwise appears to be a nearly monospecific pterosaur track assemblage. However, traces of a fifth pes digit suggest some tracks are of rhamphorynchoid rather than pterodactyloid origin, as usually inferred for Pteraichnus. The tracks occur at several horizons in a thin stratigraphic interval of ripple marked sandstones and siltstones. Overall the assemblage is similar to others found in the same time interval in the Western Interior from central and eastern Utah through central and southern Wyoming, Colorado, northeastern Arizona, and western Oklahoma. This vast "Pteraichnus ichnofacies" with associated saurischian tracks, remains the only ichnological evidence of pre-Cretaceous pterosaurs in North America and sheds important light on the vertebrate ecology of the Summerville Formation and contiguous deposits. ?? Taylor and Francis Inc.

  15. Porosity and Permeability of Jurassic-Triassic Formations of the South Georgia Rift Basin: Potential Implications for CO2 Storage

    NASA Astrophysics Data System (ADS)

    Akintunde, O. M.; Knapp, C. C.; Knapp, J. H.; Prasad, M.; Olsen, P. E.

    2011-12-01

    Porosity and permeability are critical for evaluating reservoir injectivity and seal integrity for subsurface CO2 storage. Both properties are needed to determine the effective CO2 storage capacity. In addition, the ability to model and understand the physical interactions of the CO2 reservoir systems under in situ conditions is dependent on the reservoir porosity. We present results of rock physics evaluation of the porosity and permeability of the buried Jurassic-Triassic formations of the South Georgia Rift (SGR) basin using existing well and new experimental data. The SGR basin covers parts of South Carolina, Georgia, Alabama, and Florida and is buried beneath Cretaceous and younger Coastal Plain sediments. We focused our study on the South Carolina portion of the basin that has been identified in the Carbon Sequestration Atlas of United States and Canada as containing saline formations suitable for subsurface CO2 storage. Results of our rock physics analysis confirm the presence of porous reservoir units capped by low-porosity diabase sills. These potential reservoirs appear to have the capacity (pore volume and porosity) to store significant quantities of supercritical CO2. Our analysis further suggests that the SGR basin may contain distinct porosity-permeability regimes (geo-hydrologic systems) that are influenced by depositional environments. These regimes are: (1) high-porosity, low/medium permeability, as observed in the Norris Lightsey well with Triassic formation porosity of 20 - 32.5 percent and core-derived permeability of 1.5 - 8.9 mD, and (2) low-porosity, low-permeability, based on the average total porosity of 6.3 percent and permeability of 6.6 (E-5) - 1.6 (E-2) mD reported in the literature for the Dunbarton Triassic sediments. The Norris Lightsey sedimentary rocks are primarily lacustrine deposits and consist of fine-grained Triassic sandstone with interbedded layers of siltstone and mudstone, while the Dunbarton basin is dominated by fluvial

  16. Multistage variable probability forest volume inventory. [Defiance Unit of the Navajo Nation in Arizona and Colorado

    NASA Technical Reports Server (NTRS)

    Anderson, J. E. (Principal Investigator)

    1979-01-01

    The net board foot volume (Scribner log rule) of the standing Ponderosa pine timber on the Defiance Unit of the Navajo Nation's forested land was estimated using a multistage forest volume inventory scheme with variable sample selection probabilities. The inventory designed to accomplish this task required that both LANDSAT MSS digital data and aircraft acquired data be used to locate one acre ground splits, which were subsequently visited by ground teams conducting detailed tree measurements using an optical dendrometer. The dendrometer measurements were then punched on computer input cards and were entered in a computer program developed by the U.S. Forest Service. The resulting individual tree volume estimates were then expanded through the use of a statistically defined equation to produce the volume estimate for the entire area which includes 192,026 acres and is approximately a 44% the total forested area of the Navajo Nation.

  17. Geochemistry of vanadium in an epigenetic, sandstone-hosted vanadium- uranium deposit, Henry Basin, Utah

    USGS Publications Warehouse

    Wanty, R.B.; Goldhaber, M.B.; Northrop, H.R.

    1990-01-01

    The epigenetic Tony M vanadium-uranium orebody in south-central Utah is hosted in fluvial sandstones of the Morrison Formation (Upper Jurassic). Measurements of the relative amounts of V+3 and V +4 in ore minerals show that V+3 is more abundant. Thermodynamic calculations show that vanadium was more likely transported to the site of mineralization as V+4. The ore formed as V+4 was reduced by hydrogen sulfide, followed by hydrolysis and precipitation of V+3 in oxide minerals or chlorite. Uranium was transported as uranyl ion (U+6), or some complex thereof, and reduced by hydrogen sulfide, forming coffinite. Detrital organic matter in the rocks served as the carbon source for sulfate-reducing bacteria. Vanadium most likely was derived from the dissolution of iron-titanium oxides. Uranium probably was derived from the overlying Brushy Basin Member of the Morrison Formation. Previous studies have shown that the ore formed at the density-stratified interface between a basinal brine and dilute meteoric water. The mineralization processes described above occurred within the mixing zone between these two fluids. -from Authors

  18. Preservation of anomalously high porosity in deeply buried sandstones by grain-coating chlorite: Examples from the Norwegian Continental Shelf

    SciTech Connect

    Ehrenberg, S.N. )

    1993-07-01

    Five Lower to Middle Jurassic sandstone reservoirs from the Norwegian sector provide examples of deep porosity preservation caused by grain-coating, authigenic chlorite. Wide porosity variations in clean sandstones correlate with an abundance of grain-coating chlorite and consequent inhibition of quarts cementation. Maximum porosities tend to decrease with increasing depth but generally are 10-15% higher than would be predicted from regional trends of mean porosity vs. depth. It is proposed in this paper that the high chlorite content of the porous zones reflects syndepositional concentration of Fe-rich marine clays analogous to minerals of the modern verdine facies. Fe-clay mineralization would have been localized where Fe-rich river water was discharged into the sea. The syndepositional clays were transformed during burial diagenesis into grain coatings of radially oriented chlorite crystals. Petrographic relationships indicate that these coatings grew mainly before the beginning of quartz cementation and feldspar grain dissolution (probably within the first 2 km of burial) but after grain contacts had become adjusted by mechanical compaction. The Norwegian examples demonstrate that a wide range of nearshore marine sand-body types is susceptible to chlorite mineralization. The distribution of anomalous porosity and the proportion of the net sand affected depend upon sedimentary facies architecture and the pattern of discharge of Fe-rich river water during sand deposition. This phenomenon can be critically important for hydrocarbon exploration because it can provide good reservoir quality at depths far below the [open quotes]economic basement[close quotes] originally defined on the basis of sandstones lacking chlorite coatings. 58 refs., 25 figs., 1 tab.

  19. A new carnivorous dinosaur from the Late Jurassic Solnhofen archipelago.

    PubMed

    Göhlich, Ursula B; Chiappe, Luis M

    2006-03-16

    Small Late Jurassic theropod dinosaurs are rare worldwide. In Europe these carnivorous dinosaurs are represented primarily by only two skeletons of Compsognathus, neither of which is well preserved. Here we describe a small new theropod dinosaur from the Late Jurassic period of Schamhaupten in southern Germany. Being exquisitely preserved and complete from the snout to the distal third of the tail, the new fossil is the best-preserved predatory, non-avian dinosaur in Europe. It possesses a suite of characters that support its identification as a basal coelurosaur. A cladistic analysis indicates that the new taxon is closer to maniraptorans than to tyrannosauroids, grouping it with taxa often considered to be compsognathids. Large portions of integument are preserved along its tail. The absence of feathers or feather-like structures in a fossil phylogenetically nested within feathered theropods indicates that the evolution of these integumentary structures might be more complex than previously thought. PMID:16541071

  20. Selective extinction among Early Jurassic bivalves: A consequence of anoxia

    NASA Astrophysics Data System (ADS)

    Aberhan, Martin; Baumiller, Tomasz K.

    2003-12-01

    Analyses of taxonomically standardized data sets demonstrate several statistically robust extinction patterns in Early Jurassic bivalve species from northwest Europe and the Andean basins of South America. In both regions, extinction intensities were significantly enhanced in late Pliensbachian and early Toarcian time as compared to all other time intervals. The same intervals (except for the early Toarcian of South America) also represent times of unusual extinction selectivity, with infaunal taxa suffering distinctly more than epifaunal forms. As infaunal suspension feeders are extremely rare components of Early Jurassic oxygen-controlled macrofaunas, these results are entirely compatible with sedimentological and geochemical data suggesting that widespread anoxia was a principal cause of the diversity crisis. Although many biotic traits that enhance survivorship during background times seem to be irrelevant during major mass extinctions, patterns of survivorship selectivity may provide more distinct clues to the causes of less severe mass extinctions.