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.…

Navajo Manpower Survey.

ERIC Educational Resources Information Center

Navajo Tribe, Window Rock, AZ.

The Navajo Manpower Survey for 1967, conducted on a sample of Navajos 14 years of age and older living in the Navajo Reservation area, found high rates of unemployment and underemployment for the Navajos. Some of the other findings reported are a general lack of real work experience; an indication by 70% of the labor force members that they would…

Palaeoclimatic oscillations in the Pliensbachian (Early Jurassic) of the Asturian Basin (Northern Spain)

NASA Astrophysics Data System (ADS)

Gómez, Juan J.; Comas-Rengifo, María J.; Goy, Antonio

2016-05-01

One of the main controversial themes in palaeoclimatology involves elucidating whether climate during the Jurassic was warmer than the present day and if it was the same over Pangaea, with no major latitudinal gradients. There has been an abundance of evidence of oscillations in seawater temperature throughout the Jurassic. The Pliensbachian (Early Jurassic) constitutes a distinctive time interval for which several seawater temperature oscillations, including an exceptional cooling event, have been documented. To constrain the timing and magnitude of these climate changes, the Rodiles section of the Asturian Basin (Northern Spain), a well exposed succession of the uppermost Sinemurian, Pliensbachian and Lower Toarcian deposits, has been studied. A total of 562 beds were measured and sampled for ammonites, for biochronostratigraphical purposes, and for belemnites, to determine the palaeoclimatic evolution through stable isotope studies. Comparison of the recorded latest Sinemurian, Pliensbachian and Early Toarcian changes in seawater palaeotemperature with other European sections allows characterization of several climatic changes that are likely of a global extent. A warming interval partly coinciding with a δ13Cbel negative excursion was recorded at the Late Sinemurian. After a "normal" temperature interval, with temperatures close to average values of the Late Sinemurian-Early Toarcian period, a new warming interval containing a short-lived positive δ13Cbel peak, developed during the Early-Late Pliensbachian transition. The Late Pliensbachian represents an outstanding cooling interval containing a δ13Cbel positive excursion interrupted by a small negative δ13Cbel peak. Finally, the Early Toarcian represented an exceptional warming period, which has been pointed out as being responsible for the prominent Early Toarcian mass extinction.

Early to Middle Jurassic tectonic evolution of the Bogda Mountains, Northwest China: Evidence from sedimentology and detrital zircon geochronology

NASA Astrophysics Data System (ADS)

Ji, Hongjie; Tao, Huifei; Wang, Qi; Qiu, Zhen; Ma, Dongxu; Qiu, Junli; Liao, Peng

2018-03-01

The Bogda Mountains, as an important intracontinental orogenic belt, are situated in the southern part of the Central Asian Orogenic Belt (CAOB), and are a key area for understanding the Mesozoic evolution of the CAOB. However, the tectonic evolution of the Bogda Mountains remains controversial during the Mesozoic Era, especially the Early to Middle Jurassic Periods. The successive Lower to Middle Jurassic strata are well preserved and exposed along the northern flank of the Western Bogda Mountains and record the uplift processes of the Bogda Mountains. In this study, we analysed sedimentary facies combined with detrital zircon U-Pb geochronology at five sections of Lower to Middle Jurassic strata to detect the tectonic evolution and changes of provenance in the Bogda area. During Early to Middle Jurassic times, the fluvial, deltaic and lacustrine environments dominated in the western section of the Bogda area. The existence of Early Triassic peak age indicates that the Bogda Mountains did not experience uplift during the period of early Badaowan Formation deposition. The Early Triassic to Late Permian granitoid plutons and Carboniferous volcanic rocks from the Barkol and Santanghu areas were the main provenances. The significant change in the U-Pb age spectrum implies that the Eastern Bogda Mountains initiated uplift in the period of late Badaowan Formation deposition, and the Eastern Junggar Basin and the Turpan-Hami Basin were partially partitioned. The Eastern Bogda Mountains gradually became the major provenance. From the period of early Sangonghe to early Toutunhe Formations deposition, the provenance of the sediments and basin-range frame were similar to that of late Badaowan. However, the Eastern Bogda Mountains suffered intermittent uplift three times, and successive denudation. The uplifts respectively happened in early Sangonghe, late Sangonghe to early Xishanyao, and late Xishanyao to early Toutunhe. During the deposition stage of Toutunhe Formation, a

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:…

Warm Middle Jurassic-Early Cretaceous high-latitude sea-surface temperatures from the Southern Ocean

NASA Astrophysics Data System (ADS)

Jenkyns, H. C.; Schouten-Huibers, L.; Schouten, S.; Sinninghe Damsté, J. S.

2012-02-01

Although a division of the Phanerozoic climatic modes of the Earth into "greenhouse" and "icehouse" phases is widely accepted, whether or not polar ice developed during the relatively warm Jurassic and Cretaceous Periods is still under debate. In particular, there is a range of isotopic and biotic evidence that favours the concept of discrete "cold snaps", marked particularly by migration of certain biota towards lower latitudes. Extension of the use of the palaeotemperature proxy TEX86 back to the Middle Jurassic indicates that relatively warm sea-surface conditions (26-30 °C) existed from this interval (∼160 Ma) to the Early Cretaceous (∼115 Ma) in the Southern Ocean, with a general warming trend through the Late Jurassic followed by a general cooling trend through the Early Cretaceous. The lowest sea-surface temperatures are recorded from around the Callovian-Oxfordian boundary, an interval identified in Europe as relatively cool, but do not fall below 25 °C. The early Aptian Oceanic Anoxic Event, identified on the basis of published biostratigraphy, total organic carbon and carbon-isotope stratigraphy, records an interval with the lowest, albeit fluctuating Early Cretaceous palaeotemperatures (∼26 °C), recalling similar phenomena recorded from Europe and the tropical Pacific Ocean. Extant belemnite δ18O data, assuming an isotopic composition of waters inhabited by these fossils of -1‰ SMOW, give palaeotemperatures throughout the Upper Jurassic-Lower Cretaceous interval that are consistently lower by ∼14 °C than does TEX86 and the molluscs likely record conditions below the thermocline. The long-term, warm climatic conditions indicated by the TEX86 data would only be compatible with the existence of continental ice if appreciable areas of high altitude existed on Antarctica, and/or in other polar regions, during the Mesozoic Era.

Navajo-Hopi Land Dispute: Impact of Forced Relocation on Navajo Families.

ERIC Educational Resources Information Center

Gilbert, Betty Beetso

Emphasizing the fact that the Federal government has failed to recognize the inherent differences of the Hopi and Navajo lifestyles, this study examines the century-old Navajo-Hopi American Indian land dispute; the literature on forced removal of peoples; multi-dimensional stressors associated with the forced relocation of 15 Navajo families; and…

A total petroleum system of the Browse Basin, Australia; Late Jurassic, Early Cretaceous-Mesozoic

USGS Publications Warehouse

Bishop, M.G.

1999-01-01

The Browse Basin Province 3913, offshore northern Australia, contains one important petroleum system, Late Jurassic, Early Cretaceous-Mesozoic. It is comprised of Late Jurassic through Early Cretaceous source rocks deposited in restricted marine environments and various Mesozoic reservoir rocks deposited in deep-water fan to fluvial settings. Jurassic age intraformational shales and claystones and Cretaceous regional claystones seal the reservoirs. Since 1967, when exploration began in this 105,000 km2 area, fewer than 40 wells have been drilled and only one recent oil discovery is considered potentially commercial. Prior to the most recent oil discovery, on the eastern side of the basin, a giant gas field was discovered in 1971, under a modern reef on the west side of the basin. Several additional oil and gas discoveries and shows were made elsewhere. A portion of the Vulcan sub-basin lies within Province 3913 where a small field, confirmed in 1987, produced 18.8 million barrels of oil (MMBO) up to 1995 and has since been shut in.

Geochemical Astro- and Geochronological Constraints on the Early Jurassic

NASA Astrophysics Data System (ADS)

Storm, M.; Condon, D. J.; Ruhl, M.; Jenkyns, H. C.; Hesselbo, S. P.; Al-Suwaidi, A. H.; Percival, L.

2017-12-01

The Early Jurassic Hettangian and Sinemurian time scales are poorly defined due to the lack of continuous geochemical records, and the temporal constrain of the Toarcian Oceanic Anoxic Event and associated global carbon cycle perturbation is afflicted by geochemical and biostratigraphical uncertainties of the existing radiometric dates from various volcanic ash bearing sections. Here we present a continuous, orbitally paced Hettangian to Pliensbachian carbon-isotope record of the Mochras drill-core (Cardigan bay Basin, UK). The record generates new insights into the evolution and driving mechanisms of the Early Jurassic carbon cycle, and is contributing to improve the Hettangian and Sinemurian time scale. Furthermore, we introduce a new high-resolution carbon-isotope chemostratigraphy, integrated with ammonite biostratigraphy and new U/Pb single zircon geochronology of the Las Overas section (Neuquén Basin, Argentina). The studied section comprises sediments from the tenuicostatum to Dumortiera Andean Ammonite zone (tenuicostatum to levesqui European standard zones). A stratigraphically expanded negative shift in d13Corg values, from -24‰ down to -32­‰, appears in the tenuicostatum and hoelderi ammonite zone, coeval to the negative excursion in European realm which is associated with the Toarcian Oceanic Anoxic Event. The negative isotope excursion appears concomitant with an increase in sedimentary mercury levels, indicating enhanced volcanic activity. TOC values and elemental data suggest a high sedimentation dilution in the tenuicostatum to pacificum zone. The new geochronological data from several volcanic ash beds throughout the section are further improving the temporal correlation between the Early Toarcian isotope event and causal mechanisms

Written Navajo: A Brief History. Navajo Reading Study Progress Report No. 19.

ERIC Educational Resources Information Center

Young, Robert W.

In this paper, a brief history of the Navajo written language between 1819 and the present is presented. The paper describes the progress of Navajo as a written language. The history was used as background material for a meeting organized by the Sanostee-Toadlena Navajo Bilingual Education Project. The meeting's purpose was to survey the present…

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…

Middle Jurassic - Early Cretaceous rifting on the Chortis Block in Honduras: Implications for proto-Caribbean opening (Invited)

NASA Astrophysics Data System (ADS)

Rogers, R. D.; Emmet, P. A.

2009-12-01

Regional mapping integrated with facies analysis, age constraints and airborne geophysical data reveal WNW and NE trends of Middle Jurassic to Early Cretaceous basins which intersect in southeast Honduras that we interpret as the result of rifting associated with the breakup of the Americas and opening of the proto-Caribbean seaway. The WNW-trending rift is 250 km long by 90 km wide and defined by a basal 200 to 800 m thick sequence of Middle to Late Jurassic fluvial channel and overbank deposits overlain by transgressive clastic shelf strata. At least three sub-basins are apparent. Flanking the WNW trending rift basins are fault bounded exposures of the pre-Jurassic continental basement of the Chortis block which is the source of the conglomeratic channel facies that delineate the axes of the rifts. Cretaceous terrigenous strata mantle the exposed basement-cored rift flanks. Lower Cretaceous clastic strata and shallow marine limestone strata are dominant along this trend indicating that post-rift related subsidence continued through the Early Cretaceous. The rifts coincide with a regional high in the total magnetic intensity data. We interpret these trends to reflect NNE-WSW extension active from the Middle Jurassic through Early Cretaceous. These rifts were inverted during Late Cretaceous shortening oriented normal to the rift axes. To the east and at a 120 degree angle to the WNW trending rift is the 300 km long NE trending Guayape fault system that forms the western shoulder of the Late Jurassic Agua Fria rift basin filled by > 2 km thickness of clastic marine shelf and slope strata. This NE trending basin coincides with the eastern extent of the surface exposure of continental basement rocks and a northeast-trending fabric of the Jurassic (?) metasedimentary basement rocks. We have previously interpreted the eastern basin to be the Jurassic rifted margin of the Chortis block with the Guayape originating as a normal fault system. These two rifts basin intersect

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…

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…

Navajo Tribal Education Policies. Approved November 14, 1984 [by the] Navajo Tribal Council.

ERIC Educational Resources Information Center

Navajo Tribe, Window Rock, AZ. Div. of Education.

The comprehensive educational policies adopted and incorporated into law by the Navajo Tribal Council are contained in this booklet. These policies, adopted during a special session of the Navajo Tribal Council (November 13-16, 1984), are broad statements of the educational needs and aspirations of the Navajo people. The mission statement defines…

Diabetes in Navajo Youth

PubMed Central

Dabelea, Dana; DeGroat, Joquetta; Sorrelman, Carmelita; Glass, Martia; Percy, Christopher A.; Avery, Charlene; Hu, Diana; D'Agostino, Ralph B.; Beyer, Jennifer; Imperatore, Giuseppina; Testaverde, Lisa; Klingensmith, Georgeanna; Hamman, Richard F.

2009-01-01

OBJECTIVE—To estimate the prevalence and incidence of diabetes, clinical characteristics, and risk factors for chronic complications among Navajo youth, using data collected by the SEARCH for Diabetes in Youth Study (SEARCH study). RESEARCH DESIGN AND METHODS—The SEARCH study identified all prevalent cases of diabetes in 2001 and all incident cases in 2002–2005 among Navajo youth. We estimated denominators with the user population for eligible health care facilities. Youth with diabetes also attended a research visit that included questionnaires, physical examination, blood and urine collection, and extended medical record abstraction. RESULTS—Diabetes is infrequent among Navajo youth aged <10 years. However, both prevalence and incidence of diabetes are high in older youth. Among adolescents aged 15–19 years, 1 in 359 Navajo youth had diabetes in 2001 and 1 in 2,542 developed diabetes annually. The vast majority of diabetes among Navajo youth with diabetes is type 2, although type 1 diabetes is also present, especially among younger children. Navajo youth with either diabetes type were likely to have poor glycemic control, high prevalence of unhealthy behaviors, and evidence of severely depressed mood. Youth with type 2 diabetes had more metabolic factors associated with obesity and insulin resistance (abdominal fat deposition, dyslipidemia, and higher albumin-to-creatinine ratio) than youth with type 1 diabetes. CONCLUSIONS—Our data provide evidence that diabetes is an important health problem for Navajo youth. Targeted efforts aimed at primary prevention of diabetes in Navajo youth and efforts to prevent or delay the development of chronic complications among those with diabetes are warranted. PMID:19246579

Tracking Early Jurassic marine (de)oxygenation

NASA Astrophysics Data System (ADS)

Them, T. R., II; Caruthers, A. H.; Gill, B. C.; Gröcke, D. R.; Marroquín, S. M.; Owens, J. D.

2017-12-01

It has been suggested that the carbon cycle was perturbed during the Toarcian OAE (T-OAE) as observed in the carbon isotope record, and more recently other elemental cycles (e.g., Hg, Mo, Os, S). The most widely accepted hypothesis focuses on the emplacement of the Karoo-Ferrar large igneous province, outgassing of greenhouse gases, and subsequent feedbacks in the Earth system, which caused severe environmental change and biological turnover. Feedbacks to elevated atmospheric pCO2 include enhanced weathering rates, dissociation of methane clathrates, increased terrestrial methanogenesis, and widespread marine anoxia. The sequence of events related to the development and duration of marine anoxia are not well constrained for this time interval due to a lack of open-ocean geochemical records. In order to reconstruct the timing of marine deoxygenation during the Early Jurassic T-OAE, we have utilized thallium isotopes, a novel geochemical proxy from multiple anoxic basins in North America and Germany. Three sites representing a basin transect from the Western Canada Sedimentary Basin, and one site from the South German Basin, were chosen to reconstruct the thallium isotopic composition (ɛ205Tl) of the ocean. The ɛ205Tl composition of sediments deposited under anoxic and euxinic water columns records the global seawater ɛ205Tl composition, a function of the amount of manganese oxides that are precipitated. Increased geographic extent of marine anoxia will cause a decrease in manganese oxide precipitation and perturb the thallium system. Importantly, the inputs of thallium are nearly identical, thus changes in these fluxes cannot drive the observed perturbation. Our new Early Jurassic ɛ205Tl records suggest that the onset of marine deoxygenation occurred concurrently with Karoo-Ferrar magmatism in the late Pliensbachian and continued until after the T-OAE. These new data support a Karoo-Ferrar trigger of the T-OAE. However, thallium isotopes also suggest that

A revision of Sanpasaurus yaoi Young, 1944 from the Early Jurassic of China, and its relevance to the early evolution of Sauropoda (Dinosauria)

PubMed Central

Upchurch, Paul; Mannion, Philip D.; Sullivan, Corwin; Butler, Richard J.

2016-01-01

The Early Jurassic of China has long been recognized for its diverse array of sauropodomorph dinosaurs. However, the contribution of this record to our understanding of early sauropod evolution is complicated by a dearth of information on important transitional taxa. We present a revision of the poorly known taxon Sanpasaurus yaoi Young, 1944 from the late Early Jurassic Ziliujing Formation of Sichuan Province, southwest China. Initially described as the remains of an ornithopod ornithischian, we demonstrate that the material catalogued as IVPP V156 is unambiguously referable to Sauropoda. Although represented by multiple individuals of equivocal association, Sanpasaurus is nonetheless diagnosable with respect to an autapomorphic feature of the holotypic dorsal vertebral series. Additional material thought to be collected from the type locality is tentatively referred to Sanpasaurus. If correctly attributed, a second autapomorphy is present in a referred humerus. The presence of a dorsoventrally compressed pedal ungual in Sanpasaurus is of particular interest, with taxa possessing this typically ‘vulcanodontid’ character exhibiting a much broader geographic distribution than previously thought. Furthermore, the association of this trait with other features of Sanpasaurus that are broadly characteristic of basal eusauropods underscores the mosaic nature of the early sauropod–eusauropod transition. Our revision of Sanpasaurus has palaeobiogeographic implications for Early Jurassic sauropods, with evidence that the group maintained a cosmopolitan Pangaean distribution. PMID:27781168

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.

Navajo Mineral Development

ERIC Educational Resources Information Center

Ruffing, Lorraine Turner

1978-01-01

Comparing the resource development of the Navajo Nation with that of Third World countries, this article examines Navajo-Third World similarities in terms of various decision-making alternatives such as transitional corporations and the new forms of agreements now used by Third World countries. (JC)

Health Problems of the Navajos

ERIC Educational Resources Information Center

Kaltenbach, Charles M.

1977-01-01

Summarized from a report "Health Problems of the Navajo Area and Suggested Interventions," this article discusses the death rate among Navajos as compared with the general population of the U.S., the geographic location of the Navajo nation, geographic and political factors effecting health care delivery, income, and employment. (JM)

Social Services: The Navajo Way.

ERIC Educational Resources Information Center

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

2002-01-01

Explores the Navajo Nation Division of Social Services' efforts to transform the Bureau of Indian Affairs service delivery paradigm into a more holistic case management paradigm for child and family services congruent with Navajo culture and rural location. Discusses a composite case to illustrate issues experienced by many Navajo clients.…

Navajo Electrification Demonstraiton Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Astronomical constraints on the duration of the Early Jurassic Pliensbachian Stage and global climatic fluctuations

NASA Astrophysics Data System (ADS)

Ruhl, Micha; Hesselbo, Stephen P.; Hinnov, Linda; Jenkyns, Hugh C.; Xu, Weimu; Riding, James B.; Storm, Marisa; Minisini, Daniel; Ullmann, Clemens V.; Leng, Melanie J.

2016-12-01

The Early Jurassic was marked by multiple periods of major global climatic and palaeoceanographic change, biotic turnover and perturbed global geochemical cycles, commonly linked to large igneous province volcanism. This epoch was also characterised by the initial break-up of the super-continent Pangaea and the opening and formation of shallow-marine basins and ocean gateways, the timing of which are poorly constrained. Here, we show that the Pliensbachian Stage and the Sinemurian-Pliensbachian global carbon-cycle perturbation (marked by a negative shift in δ13 C of 2- 4 ‰), have respective durations of ∼8.7 and ∼2 Myr. We astronomically tune the floating Pliensbachian time scale to the 405 Kyr eccentricity solution (La2010d), and propose a revised Early Jurassic time scale with a significantly shortened Sinemurian Stage duration of 6.9 ± 0.4 Myr. When calibrated against the new time scale, the existing Pliensbachian seawater 87Sr/86Sr record shows relatively stable values during the first ∼2 Myr of the Pliensbachian, superimposed on the long-term Early Jurassic decline in 87Sr/86Sr. This plateau in 87Sr/86Sr values coincides with the Sinemurian-Pliensbachian boundary carbon-cycle perturbation. It is possibly linked to a late phase of Central Atlantic Magmatic Province (CAMP) volcanism that induced enhanced global weathering of continental crustal materials, leading to an elevated radiogenic strontium flux to the global ocean.

Petrogenesis and tectonic implications of an Early Jurassic magmatic arc from South to East China Seas

NASA Astrophysics Data System (ADS)

Zhang, L.; Xu, C.

2017-12-01

Granite and diorite samples by drilling in northeastern South China Sea (SCS) and southwestern East China Sea (ECS) contribute key information to understanding tectonic regime of South China Block in Jurassic time. SIMS and LA-ICPMS U-Pb zircon analyses yield ages ranging from 195±2 Ma to 198±1 Ma for samples from well LF3511 in SCS, and an age of 187±1 Ma for the sample from well ESC635 in ECS. They are low temperature I-type granitoids with strongly enriched fluid-mobile elements and depleted Nb-Ta features, indicating subduction arc-related magmatism in their origin. Sr-Nd isotopic compositions for samples from SCS ((87Sr/86Sr)i=0.705494-0.706623, ɛNdt=-0.9 to +2.2) and sample from ECS ((87Sr/86Sr)i=0.705200, ɛNdt=1.1) suggest an affinity with evolved mantle-derived melts. The granitoids found from NE SCS, SE Taiwan to the SW ECS could spatially define an Early Jurassic NE-SW-trending Dongsha-Talun-Yandang low-temperature magmatic arc zone along the East Asian continental margin, paired with Jurassic accretionary complexes exposed in SW Japan, E Taiwan to the W Philippines. Its geodynamic context is associated with oblique subduction of the paleo-Pacific slab beneath Eurasia, as a mechanism responsible for early Jurassic lithospheric extension with magmatism in the South China Block.

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…

Late Jurassic-Early Cretaceous continental convergence and intracontinental orogenesis in East Asia: A synthesis of the Yanshan Revolution

NASA Astrophysics Data System (ADS)

Dong, Shuwen; Zhang, Yueqiao; Zhang, Fuqin; Cui, Jianjun; Chen, Xuanhua; Zhang, Shuanhong; Miao, Laicheng; Li, Jianhua; Shi, Wei; Li, Zhenhong; Huang, Shiqi; Li, Hailong

2015-12-01

The basic tectonic framework of continental East Asia was produced by a series of nearly contemporaneous orogenic events in the late Middle Jurassic to Early Cretaceous. Commonly, the Late Mesozoic orogenic processes were characterized by continent-continent collision, large-scale thrusting, strike-slip faulting and intense crustal shortening, crustal thickening, regional anatexis and metamorphism, followed by large-scale lithospheric extension, rifting and magmatism. To better understand the geological processes, this paper reviews and synthesizes existing multi-disciplinary geologic data related to sedimentation, tectonics, magmatism, metamorphism and geochemistry, and proposes a two-stage tectono-thermal evolutionary history of East Asia during the late Middle Jurassic to Early Cretaceous (ca. 170-120 Ma). In the first stage, three orogenic belts along the continental margins were formed coevally at ca. 170-135 Ma, i.e., the north Mongol-Okhotsk orogen, the east paleo-Pacific coastal orogen, and the west Bangong-Nujiang orogen. Tectonism related to the coastal orogen caused extensive intracontinental folding and thrusting that resulted in a depositional hiatus in the Late Jurassic, as well as crustal anatexis that generated syn-kinematic granites, adakites and migmatites. The lithosphere of the East Asian continent was thickened, reaching a maximum during the latest Jurassic or the earliest Cretaceous. In the second stage (ca. 135-120 Ma), delamination of the thickened lithosphere resulted in a remarkable (>120 km) lithospheric thinning and the development of mantle-derived magmatism, mineralization, metamorphic core complexes and rift basins. The Middle Jurassic-Early Cretaceous subduction of oceanic plates (paleo-Pacific, meso-Tethys, and Mongol-Okhotsk) and continent-continent collision (e.g. Lhasa and Qiangtang) along the East Asian continental margins produced broad coastal and intracontinental orogens. These significant tectonic activities, marked by

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.

Welcome to the Land of the Navajo. A Book of Information about the Navajo Indians. Third Edition, 1972.

ERIC Educational Resources Information Center

Correll, J. Lee, Ed.; Watson, Editha L., Ed.

Compiled and edited by the Museum and Research Department of the Navajo Tribe in 1972, the text provides information about the Navajo Indians and their vast reservation. Major areas covered include Navajo history and customs, religion, arts and crafts, Navajo tribal government and programs, Navajoland and places to go, 7 wonders of the Navajo…

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…

Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: evidence from a new genus and species, Grimmenodon aureum

PubMed Central

Stumpf, Sebastian; Ansorge, Jörg; Pfaff, Cathrin; Kriwet, Jürgen

2017-01-01

ABSTRACT A new genus and species of pycnodontiform fishes, Grimmenodon aureum, from marginal marine, marine-brackish lower Toarcian (Harpoceras exaratum ammonite subzone) clay deposits of Grimmen in northeastern Germany is described. The single specimen represents a diagnostic left prearticular dentition characterized by unique tooth arrangement and ornamentation patterns. Grimmenodon aureum, gen. et sp. nov., is the second unambiguously identified pycnodontiform species from the Early Jurassic, in addition to Eomesodon liassicus from the early Lower Jurassic of western Europe. We also report an indeterminate pycnodontiform tooth crown from the upper Pliensbachian (Pleuroceras apyrenum ammonite subzone) of the same site. The material expands the Early Jurassic range of pycnodontiforms significantly northwards and confirms their presence before and immediately following the onset of the Toarcian Oceanic Anoxic Event (T-OAE) in the marginal marine ecosystems south of the Fennoscandian Shield. Moreover, the new records indicate that the Early Jurassic diversity of pycnodontiform fishes was greater than previously assumed and probably equaled that of the Late Triassic. Therefore, it is hypothesized that the Triassic-Jurassic mass extinction event did not affect pycnodontiform fishes significantly. Micro-computed tomography was used to study the internal anatomy of the prearticular of Grimmenodon aureum, gen. et sp. nov. Our results show that no replacement teeth were formed within the tooth-bearing bone but rather were added posteriorly to functional teeth. http://zoobank.org/urn:lsid:zoobank.org:pub:A56BDE9C-40C4-4CFA-9C2E-F5FA35A66F2 Citation for this article: Stumpf, S., J. Ansorge, C. Pfaff, and J. Kriwet. 2017. Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: Evidence from a new genus and species, Grimmenodon aureum. Journal of Vertebrate Paleontology. DOI: 10

Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: evidence from a new genus and species, Grimmenodon aureum.

PubMed

Stumpf, Sebastian; Ansorge, Jörg; Pfaff, Cathrin; Kriwet, Jürgen

2017-07-04

A new genus and species of pycnodontiform fishes, Grimmenodon aureum , from marginal marine, marine-brackish lower Toarcian ( Harpoceras exaratum ammonite subzone) clay deposits of Grimmen in northeastern Germany is described. The single specimen represents a diagnostic left prearticular dentition characterized by unique tooth arrangement and ornamentation patterns. Grimmenodon aureum , gen. et sp. nov., is the second unambiguously identified pycnodontiform species from the Early Jurassic, in addition to Eomesodon liassicus from the early Lower Jurassic of western Europe. We also report an indeterminate pycnodontiform tooth crown from the upper Pliensbachian ( Pleuroceras apyrenum ammonite subzone) of the same site. The material expands the Early Jurassic range of pycnodontiforms significantly northwards and confirms their presence before and immediately following the onset of the Toarcian Oceanic Anoxic Event (T-OAE) in the marginal marine ecosystems south of the Fennoscandian Shield. Moreover, the new records indicate that the Early Jurassic diversity of pycnodontiform fishes was greater than previously assumed and probably equaled that of the Late Triassic. Therefore, it is hypothesized that the Triassic-Jurassic mass extinction event did not affect pycnodontiform fishes significantly. Micro-computed tomography was used to study the internal anatomy of the prearticular of Grimmenodon aureum , gen. et sp. nov. Our results show that no replacement teeth were formed within the tooth-bearing bone but rather were added posteriorly to functional teeth. http://zoobank.org/urn:lsid:zoobank.org:pub:A56BDE9C-40C4-4CFA-9C2E-F5FA35A66F2 Citation for this article: Stumpf, S., J. Ansorge, C. Pfaff, and J. Kriwet. 2017. Early Jurassic diversification of pycnodontiform fishes (Actinopterygii, Neopterygii) after the end-Triassic extinction event: Evidence from a new genus and species, Grimmenodon aureum . Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1344679.

Dolomitization in Late Jurassic-Early Cretaceous Platform Carbonates (Berdiga Formation), Ayralaksa Yayla (Trabzon), NE Turkey

NASA Astrophysics Data System (ADS)

Yıldız, Merve; Ziya Kırmacı, Mehmet; Kandemir, Raif

2017-04-01

ABSTRACT Pontides constitute an E-W trending orogenic mountain belt that extends about 1100 km along the northern side of Turkey from the immediate east of Istanbul to the Georgian border at the east. Tectono-stratigraphically, the Pontides are divided into three different parts: Eastern, Central, and Western Pontides. The Eastern Pontides, including the studied area, comprise an area of 500 km in length and 100 km in width, extending along the southeast coast of the Black Sea from the Kizilirmak and Yesilirmak Rivers in the vicinity of Samsun to the Little Caucasus. This area is bordered by the Eastern Black Sea basin to the north and the Ankara-Erzincan Neotethyan suture zone to the south. The Late Jurassic-Early Cretaceous platform carbonates are widely exposed in E-W direction in the Eastern Pontides (NE Turkey). The Platform carbonates shows varying lithofacies changing from supratidal to platform margin reef laterally and vertically, and was buried until the end of Late Cretaceous. The studied Ayralaksa Yayla (Trabzon, NE Turkey) area comprises one of the best typical exposures of formation in northern zone of Eastern Pontides. In this area, the lower parts of the formation are pervasively dolomitized by fabric-destructive and fabric-preserving replacement dolomite which are Ca-rich and nonstoichiometric (Ca56-66Mg34-44). Replacement dolomites (Rd) are represented by D18O values of -19.0 to -4.2 (VPDB), D13C values of 4.4 to 2.1 \\permil (VPDB) and 87Sr/86Sr ratios of 0.70889 to 0.70636. Petrographic and geochemical data indicate that Rd dolomites are formed prior to compaction at shallow-moderate burial depths from Late Jurassic-Early Cretaceous seawater and/or partly modified seawater as a result of water/rock interaction and they were recrystallized at elevated temperatures during subsequent burial. In the subsequent diagenetic process during the Late Cretaceous when the region became a magmatic arc, as a result of interaction with Early Jurassic volcanic

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…

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

USGS Publications Warehouse

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

2010-01-01

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.

NAVAJO ELECTRIFICATION DEMONSTRATION PROJECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Final Report - Navajo Electrification Demonstration Project - FY2004

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Serum cholesterol concentrations among Navajo Indians.

PubMed Central

Sugarman, J R; Gilbert, T J; Percy, C A; Peter, D G

1992-01-01

Navajo Indians have been reported by earlier investigators to have low concentrations of serum lipids and a low prevalence of hyperlipidemia, as well as low rates of ischemic heart disease. However, no data on serum lipid concentrations among Navajos have been reported for more than two decades. The authors conducted a study to determine the distribution of concentrations of serum total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, and triglyceride among persons 25-74 years old living in a representative community on the Navajo Indian reservation. Data are reported for 255 subjects, 105 men and 150 women, ages 25-74 years. The authors compared these data to those for the general population as determined by the second National Health and Nutrition Examination Survey (NHANES II). TC concentrations among Navajo men were similar to those from NHANES II. TC concentrations among younger Navajo women were similar to those for women younger than 55 years from NHANES II, but were significantly lower among older Navajo women. While 27.6 percent of men ages 25-74 years studied in NHANES II had TC concentrations greater than 240 milligrams per deciliter, 33.8 percent of Navajo men had similarly elevated TC. However, the prevalence of serum TC concentrations greater than 240 milligrams per deciliter among Navajo women (17.5 percent) was about half that among women studied in NHANES II (32.9 percent). A similar pattern was found for low density lipoprotein cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1738814

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

USGS Publications Warehouse

Milner, Andrew 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.

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

PubMed

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

2009-01-01

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. Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 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. 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.

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

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.

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…

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

Traditional versus Contemporary Navajo Views of Special Education.

ERIC Educational Resources Information Center

Medina, Catherine; Jones, Doris; Miller, Susan

A survey and interviews examined the beliefs of traditional and contemporary Navajos concerning individuals with disabilities. Participants were 30 staff members from the Kayenta and Pinon Unified School Districts (Arizona), of whom 21 were Navajos, 8 Anglos, and 1 Hispanic; 1 Anglo and 8 Navajo community professionals; and 15 Navajo parents,…

A new basal galeomorph shark (Synechodontiformes, Neoselachii) from the Early Jurassic of Europe

NASA Astrophysics Data System (ADS)

Klug, Stefanie; Kriwet, Jürgen

2008-05-01

Palaeospinacids are a group of basal galeomorph sharks and are placed in the order Synechodontiformes (Chondrichthyes, Neoselachii) ranging from the Permian to the Eocene. Currently, there is a controversy concerning the identity of diagnostic characters for distinguishing palaeospinacid genera because of very similar dental morphologies and the scarcity of articulated skeletal material. The most notable character for distinguishing species within the Palaeospinacidae is, however, the dental morphology. The main dental character uniting all palaeospinacids is the very specialised pseudopolyaulacorhize root vascularisation. A re-examination of articulated neoselachian skeletons from the Lower Jurassic of Lyme Regis (England) and Holzmaden (S Germany), and recently discovered specimens from the Upper Jurassic of the Solnhofen area and Nusplingen (S Germany) has yielded several hitherto unrecognised complete skeletons of the palaeospinacids Synechodus and Paraorthacodus enabling a re-evaluation of characters. These specimens indicate that the number of dorsal fins and the presence or absence of dorsal fin spines represent important features for identifying palaeospinacids. Synechodus bears two dorsal fins without fin spines, whereas Paraorthacodus only has a single dorsal fin lacking a fin spine directly in front of the caudal fin. All palaeospinacids from the Early Jurassic have two spines supporting the dorsal fins and are consequently assigned to a new genus, Palidiplospinax nov. gen. Three species are placed into the new taxon: Synechodus enniskilleni, S. occultidens and S. smithwoodwardi.

A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs.

PubMed

Pol, Diego; Rauhut, Oliver W M

2012-08-22

Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known. Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements. The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates.

A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs

PubMed Central

Pol, Diego; Rauhut, Oliver W. M.

2012-01-01

Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known. Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements. The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates. PMID:22628475

40 CFR 49.24 - Federal Implementation Plan Provisions for Navajo Generating Station, Navajo Nation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in a log. (f) Reporting and recordkeeping requirements. Unless otherwise stated all requests, reports... shall be submitted to the Director, Navajo Environmental Protection Agency, P.O. Box 339, Window Rock... to the Director, Navajo Environmental Protection Agency, by mail to: P.O. Box 339, Window Rock...

A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds.

PubMed

Godefroit, Pascal; Cau, Andrea; Dong-Yu, Hu; Escuillié, François; Wenhao, Wu; Dyke, Gareth

2013-06-20

The recent discovery of small paravian theropod dinosaurs with well-preserved feathers in the Middle-Late Jurassic Tiaojishan Formation of Liaoning Province (northeastern China) has challenged the pivotal position of Archaeopteryx, regarded from its discovery to be the most basal bird. Removing Archaeopteryx from the base of Avialae to nest within Deinonychosauria implies that typical bird flight, powered by the forelimbs only, either evolved at least twice, or was subsequently lost or modified in some deinonychosaurians. Here we describe the complete skeleton of a new paravian from the Tiaojishan Formation of Liaoning Province, China. Including this new taxon in a comprehensive phylogenetic analysis for basal Paraves does the following: (1) it recovers it as the basal-most avialan; (2) it confirms the avialan status of Archaeopteryx; (3) it places Troodontidae as the sister-group to Avialae; (4) it supports a single origin of powered flight within Paraves; and (5) it implies that the early diversification of Paraves and Avialae took place in the Middle-Late Jurassic period.

The conchostracan subgenus Orthestheria (Migransia) from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous, Uruguay) with notes on its geological age

NASA Astrophysics Data System (ADS)

Yanbin, Shen; Gallego, Oscar F.; Martínez, Sergio

2004-04-01

Conchostracans from the Tacuarembó Formation s.s. of Uruguay are reassigned to the subgenus Orthestheria (Migransia) Chen and Shen. They show more similarities to genera of Late Jurassic age in the Congo Basin and China than to those of Early Cretaceous age. On the basis of the character of the conchostracans, we suggest that the Tacuarembó Formation is unlikely to be older than Late Jurassic. It is probably Kimmeridgian, but an Early Cretaceous age cannot be excluded. This finding is consistent with isotopic dating of the overlying basalts, as well as the age range of recently described fossil freshwater sharks.

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…

Marine ecosystem resilience during extreme deoxygenation: the Early Jurassic oceanic anoxic event.

PubMed

Caswell, Bryony A; Frid, Christopher L J

2017-01-01

Global warming during the Early Jurassic, and associated widespread ocean deoxygenation, was comparable in scale with the changes projected for the next century. This study quantifies the impact of severe global environmental change on the biological traits of marine communities that define the ecological roles and functions they deliver. We document centennial-millennial variability in the biological trait composition of Early Jurassic (Toarcian) seafloor communities and examine how this changed during the event using biological traits analysis. Environmental changes preceding the global oceanic anoxic event (OAE) produced an ecological shift leading to stressed benthic palaeocommunities with reduced resilience to the subsequent OAE. Changes in traits and ecological succession coincided with major environmental changes; and were of similar nature and magnitude to those in severely deoxygenated benthic communities today despite the very different timescales. Changes in community composition were linked to local redox conditions whereas changes in populations of opportunists were driven by primary productivity. Throughout most of the OAE substitutions by tolerant taxa conserved the trait composition and hence functioning, but periods of severe deoxygenation caused benthic defaunation that would have resulted in functional collapse. Following the OAE recovery was slow probably because the global nature of the event restricted opportunities for recruitment from outside the basin. Our findings suggest that future systems undergoing deoxygenation may initially show functional resilience, but severe global deoxygenation will impact traits and ecosystem functioning and, by limiting the species pool, will slow recovery rates.

Type 2 diabetes mellitus in Navajo adolescents.

PubMed Central

Kim, C; McHugh, C; Kwok, Y; Smith, A

1999-01-01

Diabetes mellitus afflicts over one-fifth of the Navajo population aged over 20 years, but the prevalence of diabetes in Navajo adolescents is unclear. We conducted voluntary testing for diabetes mellitus at two high schools on the Navajo reservation to clarify the prevalence as well as to assess the utility of a high-school based screening program. Body mass index measurements (BMI), oral glucose tolerance tests, and hemoglobin A1C measurements were obtained in consenting high school students. Of the 276 students that participated, 234 were Navajo. Only one Navajo student (0.4%) had diabetes mellitus, although eight (3%) had impaired glucose tolerance or impaired fasting glucose. Participant BMI did not differ significantly from nonparticipant BMI. No correlation existed between BMI or impaired glucose handling, and significant overlap existed between the hemoglobin A1C values of students with impaired glucose handling and students without impaired glucose handling. Increased participation in screening programs may reveal higher disease prevalence, but high school-based screening is not justified by this study, despite the high rates of diabetes mellitus in the Navajo population. PMID:10344174

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…

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.

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;…

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.

Correlation of middle Jurassic San Rafael Group and related rocks from Bluff to Monticello in southeastern Utah

USGS Publications Warehouse

O'Sullivan, R. B.

2000-01-01

The Middle Jurassic San Rafael Group and the Upper Jurassic Morrison Formation consist mainly of sandstone, siltstone, and shale. The San Rafael Group is widely displayed around Bluff (fig. 1) in the southern part of the study area and along Harts Draw and Dry Valley in the northern part. Along Montezuma Canyon, which is almost 1,500 ft deep, the upper part of the group crops out for about 10 mi; at one locality (sec. 13, fig. 1) all of it is exposed. Elsewhere in the study area, younger rocks conceal the San Rafael Group. The Morrison Formation is also generally well exposed throughout the area. From near Monticello to Harts Draw, Cretaceous rocks conceal the Morrison Formation. In the study area, two unconformities are associated with the rocks described herein. One at the base of the San Rafael Group (termed J-2) at the contact with the Lower Jurassic Navajo Sandstone and the other at the top (J-5) at the contact with the overlying Morrison Formation. The J-5 unconformity is the datum used to construct the line of graphic sections and the restored stratigraphic diagram of this report. The locations of drill holes and measured sections are given in table 1.

Early Jurassic extensional inheritance in the Lurestan region of the Zagros fold-and-thrust belt, Iran.

NASA Astrophysics Data System (ADS)

Tavani, Stefano; Parente, Mariano; Vitale, Stefano; Puzone, Francesco; Erba, Elisabetta; Bottini, Cinzia; Morsalnejad, Davoud; Mazzoli, Stefano

2017-04-01

It has long been recognized that the tectonic architecture of the Zagros mountain belt was strongly controlled by inherited structures previously formed within the Arabian plate. These preexisting features span in age from the pre-Cambrian to the Mesozoic, showing different trends and deformation styles. Yet, these structures are currently not fully understood. This uncertainty is partly related with the paucity of exposures, which rarely allows a direct observation of these important deformation features. The Lurestan Province of Iran provides a remarkable exception, since it is one of the few places of the Zagros mountain belt where exposures of Triassic and Jurassic rocks are widespread. In this area we carried out structural observations on Mesozoic extensional structures developed at the southern margin of the Neo-Tethyan basin. Syn-sedimentary extensional faults are hosted within the Triassic-Cretaceous succession, being particularly abundant in the Jurassic portion of the stratigraphy. Early to Middle Jurassic syn-sedimentary faults are observed in different paleogeographic domains of the area, and their occurrence is coherent with the subsequent transition from shallow-water to deep-sea basin environments, observed in a wide portion of the area. Most of the thrusts exposed in the area may indeed be interpreted as reactivated Jurassic extensional faults, or as reverse faults whose nucleation was controlled by the location of preexisting normal faults, as a result of positive inversion during crustal shortening and mountain building.

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…

Final Report Navajo Transmission Project (NTP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains.

PubMed

Reisz, Robert R; Huang, Timothy D; Roberts, Eric M; Peng, ShinRung; Sullivan, Corwin; Stein, Koen; LeBlanc, Aaron R H; Shieh, DarBin; Chang, RongSeng; Chiang, ChengCheng; Yang, Chuanwei; Zhong, Shiming

2013-04-11

Fossil dinosaur embryos are surprisingly rare, being almost entirely restricted to Upper Cretaceous strata that record the late stages of non-avian dinosaur evolution. Notable exceptions are the oldest known embryos from the Early Jurassic South African sauropodomorph Massospondylus and Late Jurassic embryos of a theropod from Portugal. The fact that dinosaur embryos are rare and typically enclosed in eggshells limits their availability for tissue and cellular level investigations of development. Consequently, little is known about growth patterns in dinosaur embryos, even though post-hatching ontogeny has been studied in several taxa. Here we report the discovery of an embryonic dinosaur bone bed from the Lower Jurassic of China, the oldest such occurrence in the fossil record. The embryos are similar in geological age to those of Massospondylus and are also assignable to a sauropodomorph dinosaur, probably Lufengosaurus. The preservation of numerous disarticulated skeletal elements and eggshells in this monotaxic bone bed, representing different stages of incubation and therefore derived from different nests, provides opportunities for new investigations of dinosaur embryology in a clade noted for gigantism. For example, comparisons among embryonic femora of different sizes and developmental stages reveal a consistently rapid rate of growth throughout development, possibly indicating that short incubation times were characteristic of sauropodomorphs. In addition, asymmetric radial growth of the femoral shaft and rapid expansion of the fourth trochanter suggest that embryonic muscle activation played an important role in the pre-hatching ontogeny of these dinosaurs. This discovery also provides the oldest evidence of in situ preservation of complex organic remains in a terrestrial vertebrate.

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.

U.S. SCHOOL ADMINISTRATORS LEARN OF NAVAJO "REVOLUTION".

ERIC Educational Resources Information Center

BENHAM, WILLIAM J., JR.

NAVAJO CULTURE AND LANGUAGE ARE QUITE DIFFERENT FROM THAT OF OTHER AMERICANS, AND HELP TO ACCOUNT FOR GENERALLY LOW SUCCESS OF NAVAJO CHILDREN IN THE CLASSROOM. BY NOVEMBER 1966, WHEN TITLE I OF THE ELEMENTARY AND SECONDARY EDUCATION ACT HAD BECOME AVAILABLE TO FEDERAL SCHOOLS, THE NAVAJO TRIBAL COUNCIL'S EDUCATION COMMITTEE HAD DECIDED THAT WHAT…

Paleomagnetic tests for tectonic reconstructions of the Late Jurassic-Early Cretaceous Woyla Group, Sumatra

NASA Astrophysics Data System (ADS)

Advokaat, Eldert; Bongers, Mayke; van Hinsbergen, Douwe; Rudyawan, Alfend; Marshal, Edo

2017-04-01

SE Asia consists of multiple continental blocks, volcanic arcs and suture zones representing remnants of closing ocean basins. The core of this mainland is called Sundaland, and was formed by accretion of continental and arc fragments during the Paleozoic and Mesozoic. The former positions of these blocks are still uncertain but reconstructions based on tectonostratigraphic, palaeobiogeographic, geological and palaeomagnetic studies indicate the continental terranes separated from the eastern margin of Gondwana. During the mid-Cretaceous, more continental and arc fragments accreted to Sundaland, including the intra-oceanic Woyla Arc now exposed on Sumatra. These continental fragments were derived from Australia, but the former position of the Woyla Arc is unconstrained. Interpretations on the former position of the Woyla Arc fall in two end-member groups. The first group interprets the Woyla Arc to be separated from West Sumatra by a small back-arc basin. This back arc basin opened in the Late Jurassic, and closed mid-Cretaceous, when the Woyla Arc collided with West Sumatra. The other group interprets the Woyla Arc to be derived from Gondwana, at a position close to the northern margin of Greater India in the Late Jurassic. Subsequently the Woyla Arc moved northwards and collided with West Sumatra in the mid-Cretaceous. Since these scenarios predict very different plate kinematic evolutions for the Neotethyan realm, we here aim to place paleomagnetic constraints on paleolatitudinal evolution of the Woyla Arc. The Woyla Arc consists mainly of basaltic to andesitic volcanics and dykes, and volcaniclastic shales and sandstones. Associated limestones with volcanic debris are interpreted as fringing reefs. This assemblage is interpreted as remnants of an Early Cretaceous intra-oceanic arc. West Sumatra exposes granites, surrounded by quartz sandstones, shales and volcanic tuffs. These sediments are in part metamorphosed. This assemblage is interpreted as a Jurassic-Early

Petrogenesis of early Jurassic basalts in southern Jiangxi Province, South China: Implications for the thermal state of the Mesozoic mantle beneath South China

NASA Astrophysics Data System (ADS)

Cen, Tao; Li, Wu-xian; Wang, Xuan-ce; Pang, Chong-jin; Li, Zheng-xiang; Xing, Guang-fu; Zhao, Xi-lin; Tao, Jihua

2016-07-01

Early Jurassic bimodal volcanic and intrusive rocks in southern South China show distinct associations and distribution patterns in comparison with those of the Middle Jurassic and Cretaceous rocks in the area. It is widely accepted that these rocks formed in an extensional setting, although the timing of the onset and the tectonic driver for extension are debated. Here, we present systematic LA-ICP-MS zircon U-Pb ages, whole-rock geochemistry and Sr-Nd isotope data for bimodal volcanic rocks from the Changpu Formation in the Changpu-Baimianshi and Dongkeng-Linjiang basins in southern Jiangxi Province, South China. Zircon U-Pb ages indicate that the bimodal volcanic rocks erupted at ca. 190 Ma, contemporaneous with the Fankeng basalts ( 183 Ma). A compilation of geochronological results demonstrates that basin-scale basaltic eruptions occurred during the Early Jurassic within a relatively short interval (< 5 Ma). These Early Jurassic basalts have tholeiitic compositions and OIB-like trace element distribution patterns. Geochemical analyses show that the basalts were derived from depleted asthenospheric mantle, dominated by a volatile-free peridotite source. The calculated primary melt compositions suggest that the basalts formed at 1.9-2.1 GPa, with melting temperatures of 1378 °C-1405 °C and a mantle potential temperature (TP) ranging from 1383 °C to 1407 °C. The temperature range is somewhat hotter than normal mid-ocean-basalt (MORB) mantle but similar to an intra-plate continental mantle setting, such as the Basin and Range Province in western North America. This study provides an important constraint on the Early Jurassic mantle thermal state beneath South China. Reference: Raczek, I., Stoll, B., Hofmann, A.W., Jochum, K.P. 2001. High-precision trace element data for the USGS reference materials BCR-1, BCR-2, BHVO-1, BHVO-2, AGV-1, AGV-2, DTS-1, DTS-2, GSP-1 and GSP-2 by ID-TIMS and MIC-SSMS. Geostandards Newsletter 25(1), 77-86.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust allotments... granted the Navajo Nation primacy for the SDWA Class II UIC program”), is the program administered by the Navajo Nation approved by EPA pursuant to section 1425 of the SDWA. Notice of this approval was published...

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

Code of Federal Regulations, 2011 CFR

2011-07-01

... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust allotments... granted the Navajo Nation primacy for the SDWA Class II UIC program”), is the program administered by the Navajo Nation approved by EPA pursuant to section 1425 of the SDWA. Notice of this approval was published...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust allotments... granted the Navajo Nation primacy for the SDWA Class II UIC program”), is the program administered by the Navajo Nation approved by EPA pursuant to section 1425 of the SDWA. Notice of this approval was published...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust allotments... granted the Navajo Nation primacy for the SDWA Class II UIC program”), is the program administered by the Navajo Nation approved by EPA pursuant to section 1425 of the SDWA. Notice of this approval was published...

Literature on Early Literacy Instruction in Four Languages (Chinese, Korean, Navajo, Russian).

ERIC Educational Resources Information Center

Thurlow, Martha; Liu, Kristin; Albus, Debra; Shyyan, Vitaliy

2003-01-01

This report, sponsored by the Office of English Language Acquisition (OELA), is a summary of evidence-based research on teaching reading to Chinese, Korean, Navajo, and Russian children. It complements a recent summary of the literature on teaching reading to Spanish speaking students. There is a significant need for evidence-based research on…

Triassic–Jurassic mass extinction as trigger for the Mesozoic radiation of crocodylomorphs

PubMed Central

Toljagić, Olja; Butler, Richard J.

2013-01-01

Pseudosuchia, one of the two main clades of Archosauria (Reptilia: Diapsida), suffered a major decline in lineage diversity during the Triassic–Jurassic (TJ) mass extinction (approx. 201 Ma). Crocodylomorpha, including living crocodilians and their extinct relatives, is the only group of pseudosuchians that survived into the Jurassic. We reassess changes in pseudosuchian morphological diversity (disparity) across this time interval, using considerably larger sample sizes than in previous analyses. Our results show that metrics of pseudosuchian disparity did not change significantly across the TJ boundary, contrasting with previous work suggesting low pseudosuchian disparity in the Early Jurassic following the TJ mass extinction. However, a significant shift in morphospace occupation between Late Triassic and Early Jurassic taxa is recognized, suggesting that the TJ extinction of many pseudosuchian lineages was followed by a major and geologically rapid adaptive radiation of crocodylomorphs. This marks the onset of the spectacularly successful evolutionary history of crocodylomorphs in Jurassic and Cretaceous ecosystems. PMID:23536443

Jurassic faults of southwest Alabama and offshore areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mink, R.M.; Tew, B.H.; Bearden, B.L.

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 Latemore » 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.« less

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)

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

This report presents the results of a study of bedrock aquifers in the northern San Rafael Swell area, Utah (fig. 1), with special emphasis on the Navajo Sandstone of Triassic(?) and Jurassic age. The study was made by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights. Fieldwork was done mainly during March 1979-July 1980, with supplemental testing and observations during August-December 1980.The principal objectives of this study were to determine: (1) Well yields of the bedrock formations, (2) the capability of formations to yield, over the long term, water chemically suitable for presently (1980) known uses, and (3) effects of withdrawals from wells on the surface-water supply in the Colorado River Basin.

Ammonite paleobiogeography during the Pliensbachian-Toarcian crisis (Early Jurassic) reflecting paleoclimate, eustasy, and extinctions

NASA Astrophysics Data System (ADS)

Dera, Guillaume; Neige, Pascal; Dommergues, Jean-Louis; Brayard, Arnaud

2011-08-01

The Pliensbachian-Toarcian crisis (Early Jurassic) is one of the major Mesozoic paleoecological disturbances when ca. 20% of marine and continental families went extinct. Contemporaneously, profound paleobiogeographical changes occurred in most oceanic domains including a disruption of ammonite provincialism during the Early Toarcian. Here, we quantitatively reappraise the structure and evolution of paleobiogeographical patterns displayed by ammonite faunas before, during, and after the biological crisis, over a time-interval including 13 biochronozones. The high-resolution study presented here involves the use of hierarchical Cluster Analyses, non-metric Multi-Dimensional Scaling methods, and Bootstrap Spanning Network approaches that we apply to a large database including 772 ammonite species from 16 northwestern Tethyan and Arctic basins. Our results confirm a robust faunal dichotomy between Euro-Boreal and Mediterranean areas throughout the Pliensbachian, with the first emergence of an Arctic biome during the cooling regressive event of the Spinatum Zone. Whatever its complexity, Pliensbachian provincialism could be directly linked to paleogeographical barriers and to latitudinal paleoclimatic and paleoecological contrasts. During the Early Toarcian, this pattern was progressively lost, with northward expansions of Mediterranean ammonites during the Tenuicostatum Zone, followed by a strong interprovincial mixing during the Falciferum Zone. This faunal homogenization results from the combination of several parameters including a major sea-level rise facilitating basinal connections, a global warming event stretching the spatial range limits of southern taxa, and a mass extinction preferentially removing endemic species. Ammonite provincialism, although slightly different, was progressively re-established during the cooling regressive trend of the Middle Toarcian. These results therefore suggest a paramount influence of paleoclimatic, eustatic, and extinction

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

Livestock impacts for management of reclaimed land at Navajo Mine: The decision-making process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Estrada, O.J.; Grogan, S.; Gadzia, K.L.

1997-12-31

Livestock grazing is the post-mining use for reclaimed land at Navajo Mine, a large surface coal mine on the Navajo Nation in northwest New Mexico. The Navajo Mine Grazing Management Program (GMP) uses holistic management on approximately 2,083 ha of reclaimed land to plan for final liability release and return of the land to the Navajo Nation, and to minimize the potential for post-release liability. The GMP began in 1991 to establish that livestock grazing on the reclaimed land is sustainable. Assuming that sustainability requires alternatives to conventional land management practices, the GMP created a Management Team consisting of companymore » staff, local, Navajo Nation, and Federal government officials, and technical advisors. Community members contributed to the formation of a holistic goal for the GMP that articulates their values and their desire for sustainable grazing. Major decisions (e.g., artificial insemination, water supply, supplemental feed) are tested against the goal. Biological changes in the land and the grazing animals are monitored daily to provide early feedback to managers, and annually to document the results of grazing. To date, the land has shown resilience to grazing and the animals have generally prospered. Community participation in the GMP and public statements of support by local officials indicate that the GMP`s strategy is likely to succeed.« less

Jurassic cooling ages in Paleozoic to early Mesozoic granitoids of northeastern Patagonia: 40Ar/39Ar, 40K-40Ar mica and U-Pb zircon evidence

NASA Astrophysics Data System (ADS)

Martínez Dopico, Carmen I.; Tohver, Eric; López de Luchi, Mónica G.; Wemmer, Klaus; Rapalini, Augusto E.; Cawood, Peter A.

2017-10-01

U-Pb SHRIMP zircon crystallization ages and Ar-Ar and K-Ar mica cooling ages for basement rocks of the Yaminué and Nahuel Niyeu areas in northeastern Patagonia are presented. Granitoids that cover the time span from Ordovician to Early Triassic constitute the main outcrops of the western sector of the Yaminué block. The southern Yaminué Metaigneous Complex comprises highly deformed Ordovician and Permian granitoids crosscut by undeformed leucogranite dikes (U-Pb SHRIMP zircon age of 254 ± 2 Ma). Mica separates from highly deformed granitoids from the southern sector yielded an Ar-Ar muscovite age of 182 ± 3 Ma and a K-Ar biotite age of 186 ± 2 Ma. Moderately to highly deformed Permian to Early Triassic granitoids made up the northern Yaminué Complex. The Late Permian to Early Triassic (U-Pb SHRIMP zircon age of 252 ± 6 Ma) Cabeza de Vaca Granite of the Yaminué block yielded Jurassic mica K-Ar cooling ages (198 ± 2, 191 ± 1, and 190 ± 2 Ma). At the boundary between the Yaminué and Nahuel Niyeu blocks, K-Ar muscovite ages of 188 ± 3 and 193 ± 5 Ma were calculated for the Flores Granite, whereas the Early Permian Navarrete granodiorite, located in the Nahuel Niyeu block, yielded a K-Ar biotite age of 274 ± 4 Ma. The Jurassic thermal history is not regionally uniform. In the supracrustal exposures of the Nahuel Niyeu block, the Early Permian granitoids of its western sector as well as other Permian plutons and Ordovician leucogranites located further east show no evidence of cooling age reset since mica ages suggest cooling in the wake of crystallization of these intrusive rocks. In contrast, deeper crustal levels are inferred for Permian-Early Triassic granitoids in the Yaminué block since cooling ages for these rocks are of Jurassic age (198-182 Ma). Jurassic resetting is contemporaneous with the massive Lower Jurassic Flores Granite, and the Marifil and Chon Aike volcanic provinces. This intraplate deformational pulse that affected northeastern

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…

"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…

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…

[A Spoken Word Count of Six-Year-Old Navajo Children, with Supplement--Complete Word List.] Navajo Reading Study Progress Report No. 10.

ERIC Educational Resources Information Center

Spolsky, Bernard; And Others

As part of a study of the feasibility and effect of teaching Navajo children to read their own language first, a word count collected by 22 Navajo adults interviewing over 200 Navajo 6-year-olds was undertaken. This report discusses the word count and the interview texts in terms of (1) number of sentences, (2) number of words, (3) number of…

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…

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)

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.

Navajo Games.

ERIC Educational Resources Information Center

Cliff, Janet M.

1990-01-01

Reviews 163 sources on Navajo games, play, and toys. Includes an annotated bibliography of those materials. Examines relationships between games and religion, origin myths, and ceremonies. Discusses attitudes toward games, gambling, and cheating; and the dichotomy between children's and adults' games. Describes specific toys, games, and play…

Late Jurassic - Early Cretaceous convergent margins of Northeastern Asia with Northwestern Pacific and Proto-Arctic oceans

NASA Astrophysics Data System (ADS)

Sokolov, Sergey; Luchitskaya, Marina; Tuchkova, Marianna; Moiseev, Artem; Ledneva, Galina

2013-04-01

Continental margin of Northeastern Asia includes many island arc terranes that differ in age and tectonic position. Two convergent margins are reconstructed for Late Jurassic - Early Cretaceous time: Uda-Murgal and Alazeya - Oloy island arc systems. A long tectonic zone composed of Upper Jurassic to Lower Cretaceous volcanic and sedimentary rocks is recognized along the Asian continent margin from the Mongol-Okhotsk thrust-fold belt on the south to the Chukotka Peninsula on the north. This belt represents the Uda-Murgal arc, which was developed along the convergent margin between Northeastern Asia and Northwestern Meso-Pacific. Several segments are identified in this arc based upon the volcanic and sedimentary rock assemblages, their respective compositions and basement structures. The southern and central parts of the Uda-Murgal island arc system were a continental margin belt with heterogeneous basement represented by metamorphic rocks of the Siberian craton, the Verkhoyansk terrigenous complex of Siberian passive margin and the Koni-Taigonos late Paleozoic to early Mesozoic island arc with accreted oceanic terranes. At the present day latitude of the Pekulney and Chukotka segments there was an ensimatic island arc with relicts of the South Anyui oceanic basin in backarc basin. Alazeya-Oloy island arc systems consists of Paleozoic and Mesozoic complexes that belong to the convergent margin between Northeastern Asia and Proto-Artic Ocean. It separated structures of the North American and Siberian continents. The Siberian margin was active whereas the North American margin was passive. The Late Jurassic was characterized by termination of a spreading in the Proto-Arctic Ocean and transformation of the latter into the closing South Anyui turbidite basin. In the beginning the oceanic lithosphere and then the Chukotka microcontinent had been subducted beneath the Alazeya-Oloy volcanic belt

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…

"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…

Discovery of the early Jurassic Gajia mélange in the Bangong-Nujiang suture zone: Southward subduction of the Bangong-Nujiang Ocean?

NASA Astrophysics Data System (ADS)

Lai, Wen; Hu, Xiumian; Zhu, Dicheng; An, Wei; Ma, Anlin

2017-06-01

Mélange records a series of geological processes associated with oceanic subduction and continental collision. This paper reports for the first time the presence of Early Jurassic mélange from NW Nagqu in the southern margin of the Bangong-Nujiang suture zone, termed as the Gajia mélange. It shows typically blocks-in-matrix structure with matrix of black shale and siliceous mudstone, and several centimeters to several meters sized blocks of sandstone, silicalite, limestone and basalt. The sandstone blocks consist of homologous sandstone and two types of exotic sandstone, with different modal compositions. The Group 1 of exotic sandstone blocks consists of mainly of feldspar and quartz, whereas the Group 2 is rich in volcanic detritus. The Group 3 of homologous sandstone blocks is rich in feldspar and volcanic detritus with rare occurrence of quartz. U-Pb age data and in situ Hf isotopic compositions of detrital zircons from sandstone blocks are similar to those from the Lhasa terrane, suggesting that the sandstone blocks in the Gajia mélange most probably came from the Lhasa terrane. The YC1σ(2+) age of homologous sandstone blocks is 177 ± 2.4 Ma, suggesting an Early Jurassic depositional age for the sandstones within the Gajia mélange. The Gajia mélange likely records the southward subduction of the Bangong-Nujiang Ocean during the Early Jurassic.

Sedimentology of the Early Jurassic terrestrial Steierdorf Formation in Anina, Colonia Cehă Quarry, South Carpathians, Romania

NASA Astrophysics Data System (ADS)

Kędzior, Artur; Popa, Mihai E.

2013-06-01

Kędzior, A. and Popa, E.M. 2013. Sedimentology of the Early Jurassic terrestrial Steierdorf Formation in Anina, Colonia Cehă Quarry, South Carpathians, Romania. Acta Geologica Polonica, 63 (2), 175-199. Warszawa. The continental, coal bearing Steierdorf Formation, Hettangian - Sinemurian in age, is included in the Mesozoic cover of the Reşiţa Basin, Getic Nappe, South Carpathians, Romania. The Steierdorf Formation can be studied in Anina, a coal mining center and an exceptional locality for Early Jurassic flora and fauna, occurring in the middle of the Reşiţa Basin. This paper presents the results of sedimentological, stratigraphical and paleobotanical researches undertaken in Colonia Cehă open cast mine in Anina, where the Steierdorf Formation outcrops widely. Several sedimentary facies associations have been described, these associations permitting the reconstruction of various depositional systems such as alluvial fans, braided and meandering river systems, as well as lacustrine and coal generating marsh systems of the Steierdorf Formation. The sedimentary associations recorded within the Steierdorf Formation show a gradual fining upward trend, pointing to a rising marine water table and a decreasing relief within the source area.

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,…

Healthful Nutrition of Foods in Navajo Nation Stores: Availability and Pricing.

PubMed

Kumar, Gayathri; Jim-Martin, Sonlatsa; Piltch, Emily; Onufrak, Stephen; McNeil, Carrie; Adams, Laura; Williams, Nancy; Blanck, Heidi M; Curley, Larry

2016-09-01

Low availability and affordability of healthier foods in food stores on the Navajo Nation (NN) may be a community-level risk factor for the high prevalence of obesity among the Navajo people. This study assessed the availability and pricing of foods and beverages in supermarkets and convenience stores throughout the NN. Descriptive study design using the Nutrition Environment Measurement Survey in Stores audit tool. Supermarkets (n = 13) and convenience stores (n = 50) on NN and border-town supermarkets (n = 9). Not applicable. Availability and pricing of healthy and less-healthy foods. Descriptive and χ(2) analyses. Navajo convenience stores offered fewer healthier food options compared to Navajo supermarkets. In Navajo convenience stores, 100% whole grain products, reduced-fat cheese, lean meats, reduced-fat chips, and fat-free or light hot dogs were available in fewer stores than their corresponding less-healthy versions (all with p < .05). In both Navajo supermarkets and convenience stores, 100% whole wheat bread, lean cold cuts, and reduced-fat cheese were all more expensive per unit than their corresponding less-healthy versions (all with p < .05). According to this study, healthier foods are not as readily available in Navajo convenience stores as they are in Navajo supermarkets. Improving access to and affordability of healthier foods in reservation stores of all sizes may support healthy eating among Navajo residents. © 2016 by American Journal of Health Promotion, Inc.

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,…

Working with Navajo Parents of Exceptional Children.

ERIC Educational Resources Information Center

Jones, Doris; And Others

Undergraduate students at Northern Arizona University interviewed and surveyed 20 staff members at Kayenta Unified School District (KUSD) on the Navajo Reservation and 14 parents of exceptional Navajo children enrolled in KUSD. Both groups were asked to identify challenges affecting the working relationship between parents and school on a rural…

Assumptions for Bilingual Instruction in the Primary Grades of Navajo Schools.

ERIC Educational Resources Information Center

Wilson, Robert D.

A review of some assumptions made in the development and implementation of a bilingual-bicultural curriculum for Navajo students in the early primary grades is presented. The curriculum set out to develop and expand the students' abilities for learning, teaching them how to learn, so they could cope with change. It set out to sensitize them to the…

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Navajo Indian lands-Class II wells... Indian Lands § 147.3400 Navajo Indian lands—Class II wells. The UIC program for Class II injection wells... outside those exterior boundaries (collectively referred to as “Navajo Indian lands for which EPA has...

Virtual reconstruction of the endocranial anatomy of the early Jurassic marine crocodylomorph Pelagosaurus typus (Thalattosuchia)

PubMed Central

Williams, Megan; Benson, Roger B.J.

2017-01-01

Thalattosuchians were highly specialised aquatic archosaurs of the Jurassic and Early Cretaceous, and represent a peak of aquatic adaptation among crocodylomorphs. Relatively little is known of their endocranial anatomy or its relevance for the evolution of sensory systems, physiology, and other aspects of biology. Nevertheless, such data have significance for two reasons: (1) thalattosuchians represent an important data point regarding adaptation to marine life in tetrapods; and (2) as early-diverging members of the crocodylian stem-lineage, thalattosuchians provide information on the evolutionary assembly of the brain and other endocranial structures in crocodylomorphs. Here we use µCT data to virtually reconstruct the endocranial anatomy of Pelagosaurus typus, an early thalattosuchian with plesiomorphic traits of relevance to the split between the two major subgroups: Teleosauroidea and Metriorhynchoidea. Interpretation of these data in a broad comparative context indicate that several key endocranial features may be unique to thalattosuchians, including: a pyramidal morphology of the semicircular canals, the presence of an elongate endosseous cochlear duct that may indicate enhanced hearing ability, the presence of large, paired canals extending anteriorly from an enlarged pituitary fossa, a relatively straight brain (possibly due to the presence of large, laterally placed orbits), and an enlarged venous sinus projecting dorsally from the endocast that is confluent with the paratympanic sinus system. Notably, we document a large expansion of the nasal cavity anterior to the orbits in Pelagosaurus as an osteological correlate of an enlarged salt gland previously only documented in Late Jurassic metriorhynchoids. This is the first anatomical evidence of this structure in early thalattosuchians. Pelagosaurus also shares the presence of paired olfactory bulbs with metriorhynchoids, and shows an enlarged cerebrum, which may also be present in teleosauroids. Taken

Northern Edge Navajo Casino, Fruitland, NM: NN0030343

EPA Pesticide Factsheets

NPDES Permit and Fact Sheet explaining EPA's action under the Clean Water Act to issue NPDES Permit No. NN0030343) to the Navajo Tribal Utility Authority Northern Edge Navajo Casino Wastewater Treatment Facility, 2752 Indian Service Road 36, Fruitland, NM.

2014 Navajo Nation Energy and Water Consumption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singer, Suzanne L.; Woods, Sam

The Navajo Nation is the home of the largest land-based Indian reservation in the U.S., covering more than twenty-seven thousand square miles. The land in the southwestern U.S. holds an abundance of natural resources, which are intimately integrated in the history, economy, and growth of the Navajo tribe. This report aims to wholly visualize the Navajo Nation’s resources and energy and water consumption using quantitative data and systems engineering analysis. The energy and water flow chart visualizations provide structured information for tribal leaders, policymakers, and educators around energy and water system discussions, technology development opportunities, and policy decisions. The analysismore » of both energy and water is a first step to visualizing the interconnectedness and complexities of the energy-water-food nexus of the nation. The goal of this energy analysis was to first estimate coal resource consumption because of the considerable impact coal has on the Navajo economy, recently as much as $26 million per year in coal royalties.« less

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,…

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…

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…

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…

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.

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.

Cold seep-related occurrence of the Early Jurassic rhynchonellid brachiopod Anarhynchia from the Canadian Cordillera

NASA Astrophysics Data System (ADS)

Pálfy, József; Price, Gregory D.; Vörös, Attila; Kovács, Zsófia; Johannson, Gary G.

2017-04-01

Cold seeps, where seepage of methane and/or other hydrocarbon-rich fluids and hydrogen-sulfide occurs in the sea floor, are sites which harbor highly specialized ecosystems associated with distinctive carbonate sediments. Although their Mesozoic record is scarce and patchy, it commonly includes rhynchonellid brachiopods, often of large size. Each new occurrence is valuable in filling gaps and providing additional insight into these peculiar ecosystems. Here we report a monospecific assemblage of Anarhynchia from a boulder-sized limestone clast of Early Pliensbachian (Early Jurassic) age in the Inklin Formation of the Whitehorse Trough in Stikine terrane, recovered from a locality at Copper Island in Atlin Lake, northern British Columbia, Canada. Specimens are of unusually large size, up to 9 cm in length, and their external and internal morphology allows assignment to Anarhynchia but warrants introduction of a new species. Although d13C and d18O values of the shells are close to equilibrium with ancient seawater, early precipitated carbonate cement phases of the enclosing limestone are characterised by highly depleted carbon isotopic composition, indicative of the influence of microbial oxidation of methane derived from a cold seep. Carbonate petrography of the isopachous, banded-fibrous cement supports its origin in a cold seep environment. Volcanogenic detrital grains in the micritic matrix of the limestone clast are indistinguishable from those in the sandstone layers in the siliciclastic sequence, suggesting that the seep carbonate is broadly coeval with the enclosing conglomerate. Previously, Anarhynchia has been known from the Lower Jurassic of California and Oregon, from both cold seep and hydrothermal vent deposits. Our new record extends the geographic range and species-level diversity of the genus, but supports its endemism to the East Pacific and membership in chemosynthesis-based ecosystems.

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…

"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…

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.…

A record of change - Science and elder observations on the Navajo Nation

USGS Publications Warehouse

Hiza-Redsteer, Margaret M.; Wessells, Stephen M.

2017-09-20

A Record of Change - Science and Elder Observations on the Navajo Nation is a 25-minute documentary about combining observations from Navajo elders with conventional science to determine how tribal lands and culture are affected by climate change. On the Navajo Nation, there is a shortage of historical climate data, making it difficult to assess changing environmental conditions.This video reveals how a team of scientists, anthropologists, and translators combined the rich local knowledge of Navajo elders with recent scientific investigation to effectively document environmental change. Increasing aridity and declining snowfall in this poorly monitored region of the Southwest are accompanied by declining river flow and migrating sand dunes. The observations of Navajo elders verify and supplement this record of change by informing how shifting weather patterns are reflected in Navajo cultural practices and living conditions.

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…

On the age of the Jurassic-Cretaceous boundary

NASA Astrophysics Data System (ADS)

Lena, Luis; Ramos, Victor; Pimentel, Marcio; Aguirre-Urreta, Beatriz; Naipauer, Maximiliano; Schaltegger, Urs

2017-04-01

Calibrating the geologic time is of utmost importance to understanding geological and biological processes throughout Earth history. The Jurassic-Cretaceous boundary has proven to be one of the most problematic boundaries to calibrate in the geologic time. The present definition of the Jurassic-Cretaceous boundary still remains contentious mainly because of the dominant endemic nature of the flora and fauna in stratigraphic sections, which hinders an agreement on a GSSP. Consequently, an absolute and precise age for the boundary is yet to meet an agreement among the community. Additionally, integrating chemical, paleomagnetic or astronomical proxies to aid the definition of the boundary has also proven to be difficult because the boundary lacks any abrupt geochemical changes or recognizable geological events. However, the traditional Berriasella jacobi Subzone is disregarded as a primary marker and the use of calpionellids has been gaining momentum for defining the boundary. The Jurassic Cretaceous boundary in the Vaca Muerta Fm. in the Nuequen Basin of the Andes is a potential candidate for the boundary stratotype because of its high density of ammonites, nannofossils and interbedded datable horizons. Consequently, the Jurassic-Cretaceous boundary is very well defined in the Vaca Muerta Fm. On the basis of both ammonites and nannofossils. Here we present new high-precision U-Pb age determinations from two volcanic ash beds that bracket the age of the Jurassic-Cretaceous boundary: 1) ash bed LLT_14_9, with a 206Pb/238U age of 139.7 Ma, which is 2 meters above Jurassic-Cretaceous boundary based on the Argetiniceras noduliferum (Early Berriasian ) and Substeueroceras Koeneni (Late Tithonian) ammonites zone; and 2) bed LLT_14_10, with an age of 140.1 Ma, located 3m below the J-K boundary based on last occurrence of the nannofossils N. kamptneri minor and N. steinmanni minor. Therefore, we propose that the age of the Jurassic-Cretaceous boundary should be close to 140

Oxidation state inherited from the magma source and implications for mineralization: Late Jurassic to Early Cretaceous granitoids, Central Lhasa subterrane, Tibet

NASA Astrophysics Data System (ADS)

Cao, MingJian; Qin, KeZhang; Li, GuangMing; Evans, Noreen J.; McInnes, Brent I. A.; Li, JinXiang; Zhao, JunXing

2018-03-01

Arc magmas are more oxidized than mid-ocean ridge basalts; however, there is continuing debate as to whether this higher oxidation state is inherited from the source magma or developed during late-stage magmatic differentiation processes. Well-constrained Late Jurassic to Early Cretaceous arc-related intermediate to felsic rocks derived from distinct magma sources provide us with a good opportunity to resolve this enigma. A series of granitoids from the western Central Lhasa subterrane were analyzed for whole-rock magnetic susceptibility, Fe2O3/FeO ratios, and trace elements in zircon. Compared to Late Jurassic samples (1.8 ± 2.0 × 10-4 emu g-1 oe-1, Fe3+/Fetotal = 0.32 ± 0.07, zircon Ce4+/Ce3+* = 15.0 ± 13.4), Early Cretaceous rocks show higher whole-rock magnetic susceptibility (5.8 ± 2.5 × 10-4 emu g-1 oe-1), Fe3+/Fetotal ratios (0.43 ± 0.04), and zircon Ce4+/Ce3+* values (23.9 ± 22.3). In addition, positive correlations among whole-rock magnetic susceptibility, Fe3+/Fetotal ratios, and zircon Ce4+/Ce3+* reveal a slight increase in oxidation state from fO2 = QFM to NNO in the Late Jurassic to fO2 = ˜NNO in the Early Cretaceous. Obvious linear correlation between oxidation indices (whole-rock magnetic susceptibility, zircon Ce4+/Ce3+*) and source signatures (zircon ɛHf(t), TDM C ages) indicates that the oxidation state was predominantly inherited from the source with only a minor contribution from magmatic differentiation. Thus, the sources for both the Late Jurassic and Early Cretaceous rocks were probably influenced by mantle wedge-derived magma, contributing to the increased fO2. Compared to ore-forming rocks at giant porphyry Cu deposits, the relatively low oxidation state (QFM to NNO) and negative ɛHf(t) (-16 to 0) of the studied granitoids implies relative infertility. However, this study demonstrates two potential fast and effective indices ( fO2 and ɛHf(t)) to evaluate the fertility of granitoids for porphyry-style mineralization. In an

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)

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)

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;…

Navajo Area Language Arts Project (NALAP). Book 1.

ERIC Educational Resources Information Center

Eby, J. Wesley; And Others

Ten units containing 86 structural objectives make up this volume of instructional materials for the first year to year and a half of teaching English as a second language to Navajo children. The Navajo Area Language Arts Project (NALAP) materials, intended to present a sequence of English grammatical structures based on specific language and…

Navajo Community College--The President's Report, 1979-80.

ERIC Educational Resources Information Center

Jackson, Dean C.

An overview of the Navajo Community College (NCC) is presented with a message from the president and facts pertaining to both the Tsaile and Shiprock campuses. NCC President Jackson states that the uniqueness of NCC lies primarily in the instructional area which promotes the use of educational concepts contained in the Navajo culture to reinforce…

Qualitative investigation of factors contributing to effective nutrition education for Navajo families.

PubMed

Cunningham-Sabo, Leslie; Bauer, Mark; Pareo, Shirley; Phillips-Benally, Shirleen; Roanhorse, Julia; Garcia, Linda

2008-07-01

Obesity rates in American Indian and Alaskan Native children are a major health threat, yet effective ways to address this remain elusive. Building on an earlier dietary assessment of Navajo Head Start families which indicated a gap in parental nutrition awareness despite a strong program emphasis, the aim of this project was to identify culturally relevant nutrition education strategies for Navajo parents and educators of young children. Eight focus group interviews were conducted with 41 parents and early childhood education paraprofessionals to identify contributors to both healthful and unhealthy food ways of Navajo preschoolers. were presented in two community venues to verify the themes and discuss implications. Results Barriers to healthful eating included availability/cost, parenting/control, preferences/habits, time pressures, and knowledge/education. Enablers to healthful eating included the categories of schools/education, and support/modeling. Reactions to these findings during community forums suggested (1) the need for stronger parenting and parental control over the food environment; (2) community-level action to address these barriers; and (3) the need for knowledge and culturally relevant educational strategies for caregivers and children. Implications for interventions include building upon existing community resources to enhance culturally relevant and respectful parental, family, and community support for affordable and acceptable food experiences and choices for young children and their families.

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

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 withmore » 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.« less

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)

Navajo minettes in the Cerros de las Mujeres, New Mexico

NASA Astrophysics Data System (ADS)

Vaniman, D.; Laughlin, A. W.; Gladney, E. S.

1985-06-01

The Cerros de las Mujeres in west-central New Mexico are three mafic minette plugs that should be considered part of the Navajo volcanic fields on the central Colorado Plateau. This newly recognized occurrence extends the Navajo volcanic fields to the southeastern margin of the Colorado Plateau, within 45 km of the extensional tectonic setting in which the Mogollon ash-flow tuff cauldrons occur. The Cerros de las Mujeres provide additional evidence for contemporaneous sodic and potassic volcanism within the Navajo volcanic fields.

Psychosocial and health impacts of uranium mining and milling on Navajo lands.

PubMed

Dawson, Susan E; Madsen, Gary E

2011-11-01

The uranium industry in the American Southwest has had profoundly negative impacts on American Indian communities. Navajo workers experienced significant health problems, including lung cancer and nonmalignant respiratory diseases, and psychosocial problems, such as depression and anxiety. There were four uranium processing mills and approximately 1,200 uranium mines on the Navajo Nation's over 27,000 square miles. In this paper, a chronology is presented of how uranium mining and milling impacted the lives of Navajo workers and their families. Local community leaders organized meetings across the reservation to inform workers and their families about the relationship between worker exposures and possible health problems. A reservation-wide effort resulted in activists working with political leaders and attorneys to write radiation compensation legislation, which was passed in 1990 as the Radiation Exposure Compensation Act (RECA) and included underground uranium miners, atomic downwinders, and nuclear test-site workers. Later efforts resulted in the inclusion of surface miners, ore truck haulers, and millworkers in the RECA Amendments of 2000. On the Navajo Nation, the Office of Navajo Uranium Workers was created to assist workers and their families to apply for RECA funds. Present issues concerning the Navajo and other uranium-impacted groups include those who worked in mining and milling after 1971 and are excluded from RECA. Perceptions about uranium health impacts have contributed recently to the Navajo people rejecting a resumption of uranium mining and milling on Navajo lands.

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

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…

Learning to construct verbs in Navajo and Quechua.

PubMed

Courtney, Ellen H; Saville-Troike, Muriel

2002-08-01

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 verb complex in Navajo is stem-final, with prefixes appended to the stem in a rigid sequence, Quechua verbs are assembled entirely through suffixation, with some variation in affix ordering. We explore issues relevant to the acquisition of verb morphology by children learning Navajo and Quechua as their first language. Our study presents naturalistic speech samples produced by five Navajo children, aged 1;1 to 4;7, and by four Quechua-speaking children, aged 2;0 to 3;5. We centre our analysis on the role of phonological criteria in segmentation of verb stems and affixes, the production of amalgams, the problem of homophony, and the significance of distributional learning and semantic criteria in the development of the verb template. The phenomena observed in our data are discussed in light of several proposals, especially those of Peters (1983, 1995), Pinker (1984), Slobin (1985), and Hyams (1986, 1994).

Early Jurassic mafic dykes from the Xiazhuang ore district (South China): Implications for tectonic evolution and uranium metallogenesis

NASA Astrophysics Data System (ADS)

Wang, Lian-Xun; Ma, Chang-Qian; Lai, Zhong-Xin; Marks, Michael A. W.; Zhang, Chao; Zhong, Yu-Fang

2015-12-01

A comprehensive study on zircon U-Pb age dating, whole-rock geochemistry and Sr-Nd isotope data has been conducted on the mafic rocks of the Xiazhuang uranium ore district and adjacent regions in South China. Based on field work and petrographic features, three rock types (the Kuzhukeng gabbro, the WNW-trending dolerite dykes and the NNE-trending lamprophyre dykes) are distinguished. Early Jurassic SHRIMP and LA-ICPMS ages of zircon for the Kuzhukeng gabbro (198 ± 1 Ma) and WNW-trending dolerite dykes (193 ± 4 Ma) have been obtained, which are 50 Ma older than previously thought (being Cretaceous). These geochronologic data provide new evidence for the rarely identified Early Jurassic magmatisms in South China. Whole-rock geochemical data for the Kuzhukeng gabbro and WNW-trending dolerite dykes are similar, both of which being higher in FeO and TiO2 but lower in SiO2 and K2O than the NNE-trending lamprophyre dykes. Trace element characteristics and Sr-Nd isotope data indicate arc-like signatures similar to the Cretaceous southeast coast basalts of China for the lamprophyre dykes, but an OIB-like geochemical affinity for the high-TiO2 mafic rocks similar to the Permo/Triassic Emeishan flood basalts and the Middle Jurassic Ningyuan alkaline basalts. We propose that the lamprophyre dykes formed in an arc volcanic system driven by the subduction of the paleo-Pacific plate. In contrast, the Kuzhukeng gabbro and associated dolerite dykes record the post-orogenic (Indosinian) extension event in the Tethyan tectonic regime. This further implies that the Indosinian extension may have lasted until the Early Jurassic, and therefore, the subduction of the paleo-Pacific plate in south China was probably later than this period. Most U deposits of the Xiazhuang area are located at the intersection between the WNW-trending dolerite dykes and the NNE-trending faults within the Triassic granites of eastern Guidong complex, South China. Previous metallogenesis studies assumed that

Timing of the Toarcian Ocean Anoxic Event (Early Jurassic) from correlation of astronomically forced global stratigraphic sections

NASA Astrophysics Data System (ADS)

Huang, C.; Hinnov, L. A.; Hesselbo, S. P.

2012-12-01

The Early Toarcian Oceanic Anoxic Event (OAE) in the Early Jurassic Period is associated with a major negative carbon isotope excursion (CIE), mass extinction, marine transgression and global warming. The Toarcian OAE is thought to have been caused by flood basalt magmatism, and may have been a trigger for mass extinction. However, these proposed causes of the Toarcian OAE and associated biotic crisis are not adequately resolved by a precise chronology. The duration of the Toarcian OAE has been estimated to be anywhere from ~0.12 to ~0.9 Myr, most recently 0.74 to 3.26 Myr from U-Pb dating. The CIE associated with the Toarcian OAE has a similar pattern at numerous localities, and there is evidence for astronomical forcing of marine carbon isotopes. Here we estimate a duration of ~625 kyr for the main negative CIE, ~860 kyr for the polymorphum zone and >1.58 Myr for the levisoni zone based on 405-kyr astronomical eccentricity tuning of the marine section at Peniche (Portugal). This 405-kyr tuned series provides a ~2.5 Myr continuous high-resolution chronology through the Early Toarcian. There are 6, or possibly 7 short eccentricity cycles in the main CIE interval at Peniche. To confirm this astronomically based estimate, we analyzed five other sections at Yorkshire (UK), Dotternhausen (Germany), Valdorbia (Italy), Mechowo (Poland) and Serrucho, Neuquén (Argentina), from marine and terrestrial carbon isotopic series. These six stratigraphic sections from Early Jurassic western Tethys and eastern Panthalassa record the Toarcian OAE with ~6 prominent carbon isotope cycles in the CIE that provide us a 600 ± 100 kyr duration. The Peniche 405 kyr-tuned series indicates that the pre- and post-CIE intervals experienced strong precession-eccentricity-forced climate change, whereas the CIE interval is marked by dominant obliquity forcing. These dramatic and abrupt changes in astronomical response in the carbon isotopes point to fundamental shifting in the Early Toarcian

A new Cheirolepidiaceae (Coniferales) from the Early Jurassic of Patagonia (Argentina): Reconciling the records of impression and permineralized fossils.

PubMed

Escapa, Ignacio; Leslie, Andrew

2017-02-01

Plants preserved in different fossil modes provide complementary data concerning the paleobiology and evolutionary relationships among plant groups. New material from the Early Jurassic of Patagonia shows the importance of combining these sources of information, as we describe the first compression/impression fossils of Pararaucaria , a genus of the extinct conifer family Cheirolepidiaceae previously known from permineralized fossils. These fossils extend the temporal range of this genus and may allow its wider recognition in the fossil record. We studied fossil plants from the Early Jurassic (Pleinsbachian-Toarcian) locality of Taquetrén in Patagonia, Argentina using standard paleobotanical preparation and description techniques. Pararaucaria taquetrensis consists of isolated ovuliferous scales and small seed cones with helically arranged bract-scale complexes attached to scale-leaf foliage. Bract-scale complexes consist of separated bracts and ovuliferous scales with two seeds and three broad distal lobes. Pararaucaria taquetrensis represents the oldest known Cheirolepidiaceae seed cones from the Southern Hemisphere, and this material highlights the importance of compression and impression fossils in understanding the distribution of fossil taxa. This material also suggests that Cheirolepidiaceae cone scales can be easily confused with those of another common conifer family, the Araucariaceae, which has important implications for accurately understanding Mesozoic conifer diversity and paleoecology. © 2017 Botanical Society of America.

A new stem turtle from the Middle Jurassic of Scotland: new insights into the evolution and palaeoecology of basal turtles.

PubMed

Anquetin, Jérémy; Barrett, Paul M; Jones, Marc E H; Moore-Fay, Scott; Evans, Susan E

2009-03-07

The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata. Eileanchelys waldmani gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic-Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between E. waldmani and Heckerochelys romani from the Middle Jurassic of Russia. Moreover, E. waldmani also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle.

A new stem turtle from the Middle Jurassic of Scotland: new insights into the evolution and palaeoecology of basal turtles

PubMed Central

Anquetin, Jérémy; Barrett, Paul M.; Jones, Marc E.H.; Moore-Fay, Scott; Evans, Susan E.

2008-01-01

The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata. Eileanchelys waldmani gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic–Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between E. waldmani and Heckerochelys romani from the Middle Jurassic of Russia. Moreover, E. waldmani also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle. PMID:19019789

Sills, aureoles and pipes in the Karoo Basin, South Africa, as triggers for Early Jurassic environmental changes

NASA Astrophysics Data System (ADS)

Svensen, Henrik H.; Planke, Sverre; Silkoset, Petter; Hammer, Øyvind; Iyer, Karthik; Schmid, Dani W.; Chevallier, Luc

2017-04-01

Most of the Large Igneous Provinces (LIPs) formed during the last 260 million years are associated with climatic change, oceanic anoxia, or extinctions in marine and terrestrial environments. Current hypotheses involve A) degassing of carbon either from oceans or shallow sea-bed reservoirs, B) carbon and sulfur degassing from flood basalts, C) degassing from sedimentary basins heavily intruded by LIPs. Here we present new data on gas generation and degassing from the Karoo LIP, based on fieldwork, borehole studies (geochemistry, petrography), and thermal modeling. Our data expand and corroborate earlier work on the sub-volcanic processes in the Karoo Basin. We show that 1) hundreds of breccia pipes are rooted in Early Jurassic sill complexes and contact aureoles within the organic-rich Ecca Group, 2) statistical analyses reveal a fractal distribution of pipes and that they are overdispersed at small scales (<50 m), but clustered at larger scales (>800 m), 3) contact aureoles show a reduction in organic matter content towards the sill contacts, reduced to zero in the nearest zones, producing more carbon gas compared to thermal model calculations, 4) we find up to 3 permil reduction in the d13C of the organic matter remaining in the aureoles, and finally 5) some pipes contain recent oil seeps. We conclude that the sill-pipe system released thermogenic gases to the Early Jurassic atmosphere and that the pipes may have acted as permanent fluid flow pathways.

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…

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…

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…

Footwall progradation in syn-rift carbonate platform-slope systems (Early Jurassic, Northern Apennines, Italy)

NASA Astrophysics Data System (ADS)

Fabbi, Simone; Santantonio, Massimo

2012-12-01

The so-called Umbria-Marche Domain of Northern Apennines represents a vast depositional system, also stretching across the Adriatic Sea subsurface, that was characterized by dominantly pelagic sedimentation through most of its Jurassic to Oligocene/Early Miocene history. The pelagic succession is underlain by Hettangian shallow-water carbonates (Calcare Massiccio Fm.), constituting a regional carbonate platform that was subjected to tectonic extension due to rifting of the Adria/African Plate in the earliest Jurassic. While tectonic subsidence of the hangingwalls drove the drowning of the platform around the Hettangian/Sinemurian boundary, the production of benthic carbonate on footwall blocks continued parallel to faulting, through a sequence of facies that was abruptly terminated by drowning and development of condensed pelagites in the early Pliensbachian. By then rifting had ceased, so that the Pliensbachian to Early Cretaceous hangingwall deposits represent a post-rift basin-fill succession onlapping the tectonically-generated escarpment margins of the highs. During the early phases of syndepositional faulting, the carbonate factories of footwall blocks were still temporarily able to fill part of the accommodation space produced by the normal faults by prograding into the incipient basins. In this paper we describe for the first time a relatively low-angle (< 10°) clinoform bed package documenting such an ephemeral phase of lateral growth of a carbonate factory. The clinoforms are sigmoidal, and form low-relief (maximum 5-7 m) bodies representing a shallow-water slope that was productive due to development of a Lithocodium-dominated factory. Continued faulting and hangingwall subsidence then decoupled the slope from the platform top, halting the growth of clinoforms and causing the platform margin to switch from accretionary to bypass mode as the pre-rift substrate became exposed along a submarine fault escarpment. The downfaulted clinoform slope was then

Hydrology and hydrogeology of Navajo Lake, Kane County, Utah

USGS Publications Warehouse

Wilson, Milton Theurer; Thomas, Harold E.

1964-01-01

Navajo Lake, whose entire outflow disappears underground, is on the high Markagurit Plateau where the average annual precipitation is more than 30 inches. It nestles among the headwaters of several streams that flow into arid regions where competition for municipal, industrial, and irrigation water sup- plies is very keen. Several proposals for additional development and use of the water of Navajo Lake have led to controversies and raised questions in regard to the total water supply and its disposition, and to the effect of the proposed projects on existing water rights. This report summarizes the results of an investigation of the water supply of Navajo Lake and the present disposition of that supply.

Transition of Navajo Special Education Students in a Rural Environment.

ERIC Educational Resources Information Center

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

The Kayenta Unified School District (KUSD)(Arizona) transition program helps prepare Dine (Navajo) special education students for postsecondary opportunities within their own communities and outside the Navajo Reservation. The senior transition class entails a year-long course that focuses on the application process for tribal and federal…

A Feasibility Study to Evaluate Wind Energy Potential on the Navajo Nation

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 themore » 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.« less

The Chachil Limestone (Pliensbachian-earliest Toarcian) Neuquén Basin, Argentina: U-Pb age calibration and its significance on the Early Jurassic evolution of southwestern Gondwana

NASA Astrophysics Data System (ADS)

Leanza, H. A.; Mazzini, A.; Corfu, F.; Llambías, E. J.; Svensen, H.; Planke, S.; Galland, O.

2013-03-01

New radiometric U-Pb ages obtained on zircon crystals from Early Jurassic ash layers found within beds of the Chachil Limestone at its type locality in the Chachil depocentre (southern Neuquén Basin) confirm a Pliensbachian age (186.0 ± 0.4 Ma). Additionally, two ash layers found in limestone beds in Chacay Melehue at the Cordillera del Viento depocentre (central Neuquén Basin) gave Early Pliensbachian (185.7 ± 0.4 Ma) and earliest Toarcian (182.3 ± 0.4 Ma) U-Pb zircon ages. Based on these new datings and regional geological observations, we propose that the limestones cropping out at Chacay Melehue are correlatable with the Chachil Limestone. Recent data by other authors from limestones at Serrucho creek in the upper Puesto Araya Formation (Valenciana depocentre, southern Mendoza) reveal ages of 182.16 ± 0.6 Ma. Based on these new evidences, we consider the Chachil Limestone an important Early Jurassic stratigraphic marker, representing an almost instantaneous widespread flooding episode in western Gondwana. The unit marks the initiation in the Neuquén Basin of the Cuyo Group, followed by widespread black shale deposition. Accordingly, these limestones can be regarded as the natural seal of the Late Triassic -earliest Jurassic Precuyano Cycle, which represents the infill of halfgrabens and/or grabens related to a strong extensional regime. Paleontological evidence supports that during Pliensbachian-earliest Toarcian times these limestones were deposited in western Gondwana in marine warm water environments.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 marketingmore » tools to support outreach efforts targeting the public, vendors, investors and government audiences.« less

Navajo Tribal Utility Authority Shiprock Wastewater Treatment Facility; Draft NPDES Permit

EPA Pesticide Factsheets

EPA is proposing to issue a NPDES permit (No. NN0020621) to Navajo Tribal Utility Authority (NTUA) for the Shiprock wastewater treatment facility in San Juan County, New Mexico, within the northeastern portion of the Navajo Nation.

The Oldest Jurassic Dinosaur: A Basal Neotheropod from the Hettangian of Great Britain.

PubMed

Martill, David M; Vidovic, Steven U; Howells, Cindy; Nudds, John R

2016-01-01

Approximately 40% of a skeleton including cranial and postcranial remains representing a new genus and species of basal neotheropod dinosaur is described. It was collected from fallen blocks from a sea cliff that exposes Late Triassic and Early Jurassic marine and quasi marine strata on the south Wales coast near the city of Cardiff. Matrix comparisons indicate that the specimen is from the lithological Jurassic part of the sequence, below the first occurrence of the index ammonite Psiloceras planorbis and above the last occurrence of the Rhaetian conodont Chirodella verecunda. Associated fauna of echinoderms and bivalves indicate that the specimen had drifted out to sea, presumably from the nearby Welsh Massif and associated islands (St David's Archipelago). Its occurrence close to the base of the Blue Lias Formation (Lower Jurassic, Hettangian) makes it the oldest known Jurassic dinosaur and it represents the first dinosaur skeleton from the Jurassic of Wales. A cladistic analysis indicates basal neotheropodan affinities, but the specimen retains plesiomorphic characters which it shares with Tawa and Daemonosaurus.

The first megatheropod tracks from the Lower Jurassic upper Elliot Formation, Karoo Basin, Lesotho

PubMed Central

Bordy, E. M.; Abrahams, M.; Knoll, F.; McPhee, B. W.

2017-01-01

A palaeosurface with one megatheropod trackway and several theropod tracks and trackways from the Lower Jurassic upper Elliot Formation (Stormberg Group, Karoo Supergroup) in western Lesotho is described. The majority of the theropod tracks are referable to either Eubrontes or Kayentapus based on their morphological characteristics. The larger megatheropod tracks are 57 cm long and have no Southern Hemisphere equivalent. Morphologically, they are more similar to the Early Jurassic Kayentapus, as well as the much younger Upper Cretaceous ichnogenus Irenesauripus, than to other contemporaneous ichnogenera in southern Africa. Herein they have been placed within the ichnogenus Kayentapus and described as a new ichnospecies (Kayentapus ambrokholohali). The tracks are preserved on ripple marked, very fine-grained sandstone of the Lower Jurassic upper Elliot Formation, and thus were made after the end-Triassic mass extinction event (ETE). This new megatheropod trackway site marks the first occurrence of very large carnivorous dinosaurs (estimated body length >8–9 meters) in the Early Jurassic of southern Gondwana, an evolutionary strategy that was repeatedly pursued and amplified in the following ~135 million years, until the next major biotic crisis at the end-Cretaceous. PMID:29069093

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)

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)

Lessons from the Navajo: assistance with environmental data collection ensures cultural humility and data relevance.

PubMed

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

2007-01-01

The Navajo Nation suffers from a legacy of environmental pollution from historical uranium mining activities, resulting in adverse public health outcomes and continuous exposure. 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. Attend community meetings, acquire Navajo language skills, and integrate local knowledge into sampling approach of sediment, water, and vegetation. 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. Community engagement helps to sustain equitable partnerships and aids in culturally appropriate, relevant data collection.

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

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

CarbonSAFE Rocky Mountain Phase I : Seismic Characterization of the Navajo Reservoir, Buzzard Bench, Utah

NASA Astrophysics Data System (ADS)

Haar, K. K.; Balch, R. S.; Lee, S. Y.

2017-12-01

The CarbonSAFE Rocky Mountain project team is in the initial phase of investigating the regulatory, financial and technical feasibility of commercial-scale CO2 capture and storage from two coal-fired power plants in the northwest region of the San Rafael Swell, Utah. The reservoir interval is the Jurassic Navajo Sandstone, an eolian dune deposit that at present serves as the salt water disposal reservoir for Ferron Sandstone coal-bed methane production in the Drunkards Wash field and Buzzard Bench area of central Utah. In the study area the Navajo sandstone is approximately 525 feet thick and is at an average depth of about 7000 feet below the surface. If sufficient porosity and permeability exist, reservoir depth and thickness would provide storage for up to 100,000 metric tonnes of CO2 per square mile, based on preliminary estimates. This reservoir has the potential to meet the DOE's requirement of having the ability to store at least 50 million metric tons of CO2 and fulfills the DOE's initiative to develop protocols for commercially sequestering carbon sourced from coal-fired power plants. A successful carbon storage project requires thorough structural and stratigraphic characterization of the reservoir, seal and faults, thereby allowing the creation of a comprehensive geologic model with subsequent simulations to evaluate CO2/brine migration and long-term effects. Target formation lithofacies and subfacies data gathered from outcrop mapping and laboratory analysis of core samples were developed into a geologic model. Synthetic seismic was modeled from this, allowing us to seismically characterize the lithofacies of the target formation. This seismic characterization data was then employed in the interpretation of 2D legacy lines which provided stratigraphic and structural control for more accurate model development of the northwest region of the San Rafael Swell. Developing baseline interpretations such as this are crucial toward long-term carbon storage

78 FR 16825 - Approval of Air Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

... Quality Implementation Plans; Navajo Nation; Regional Haze Requirements for Navajo Generating Station... source-specific federal implementation plan (FIP) requiring the Navajo Generating Station (NGS), located... . SUPPLEMENTARY INFORMATION: Throughout this document, ``we'', ``us'', and ``our'' refer to EPA. Table of Contents...

On Resolving a Paradox in the Analysis of Navajo Syntax.

ERIC Educational Resources Information Center

Jelinek, Eloise

An analysis of relative clauses in Navajo looks at a paradox that is rooted in the assumption that in Navajo, as in English, argument positions not occupied by some free lexical item must be occupied categorically by an EC. It examines patterns of and constraints on nominals with relation to the relative clause, theory concerning argumental…

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.

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

Middle-Upper Triassic and Middle Jurassic tetrapod track assemblages of southern Tunisia, Sahara Platform

NASA Astrophysics Data System (ADS)

Niedźwiedzki, Grzegorz; Soussi, Mohamed; Boukhalfa, Kamel; Gierliński, Gerard D.

2017-05-01

Three tetrapod track assemblages from the early-middle Mesozoic of southern Tunisia are reported. The strata exposed at the Tejra 2 clay-pit near the Medenine and Rehach site, located in the vicinity of Kirchaou, contain the first tetrapod tracks found in the Triassic of Tunisia. The Middle Jurassic (early Aalenian) dinosaur tracks are reported from the Mestaoua plain near Tataouine. In the Middle Triassic outcrop of the Tejra 2 clay-pit, tridactyl tracks of small and medium-sized dinosauromorphs, were discovered. These tracks represent the oldest evidence of dinosaur-lineage elements in the Triassic deposits of Tunisia. Similar tracks have been described from the Middle Triassic of Argentina, France and Morocco. An isolated set of the manus and pes of a quadrupedal tetrapod discovered in Late Triassic Rehach tracksite is referred to a therapsid tracemaker. The Middle Jurassic deposits of the Mestaoua plain reveal small and large tridactyl theropod dinosaur tracks (Theropoda track indet. A-C). Based on comparison with the abundant record of Triassic tetrapod ichnofossils from Europe and North America, the ichnofauna described here indicates the presence of a therapsid-dinosauromorph ichnoassociation (without typical Chirotheriidae tracks) in the Middle and Late Triassic, which sheds light on the dispersal of the Middle-Upper Triassic tetrapod ichnofaunas in this part of Gondwana. The reported Middle Jurassic ichnofauna show close similarities to dinosaur track assemblages from the Lower and Middle Jurassic of northwestern Africa, North America, Europe and also southeastern Asia. Sedimentological and lithostratigraphic data of each new tracksite have been defined on published data and new observations. Taken together, these discoveries present a tantalizing window into the evolutionary history of tetrapods from the Triassic and Jurassic of southern Tunisia. Given the limited early Mesozoic tetrapod record from the region, these discoveries are of both temporal and

Satellite-Based Drought Reporting on the Navajo Nation

NASA Technical Reports Server (NTRS)

McCullum, Amber; Schmidt, Cynthia; Ly, Vickie; Green, Rachel; McClellan, Carlee

2017-01-01

The Navajo Nation (NN) is the largest reservation in the US, and faces challenges related to water management during long-term and widespread drought episodes. The Navajo Nation is a federally recognized tribe, which has boundaries within Arizona, New Mexico, and Utah. The Navajo Nation has a land area of over 70,000 square kilometers. The Navajo Nation Department of Water Resources (NNDWR) reports on drought and climatic conditions through the use of regional Standardized Precipitation Index (SPI) values and a network of in-situ rainfall, streamflow, and climate data. However, these data sources lack the spatial detail and consistent measurements needed to provide a coherent understanding of the drought regime within the Nation's regional boundaries. This project, as part of NASA's Western Water Applications Office (WWAO), improves upon the recently developed Drought Severity Assessment Tool (DSAT) to ingest satellite-based precipitation data to generate SPI values for specific administrative boundaries within the reservation. The tool aims to: (1) generate SPI values and summary statistics for regions of interest on various timescales, (2) to visualize SPI values within a web-map application, and (3) produce maps and comparative statistical outputs in the format required for annual drought reporting. The co-development of the DSAT with NN partners is integral to increasing the sustained use of Earth Observations for water management applications. This tool will provide data to support the NN in allocation of drought contingency dollars to the regions most adversely impacted by declines in water availability.

Satellite-based Drought Reporting on the Navajo Nation

NASA Astrophysics Data System (ADS)

McCullum, A. J. K.; Schmidt, C.; Ly, V.; Green, R.; McClellan, C.

2017-12-01

The Navajo Nation (NN) is the largest reservation in the US, and faces challenges related to water management during long-term and widespread drought episodes. The Navajo Nation is a federally recognized tribe, which has boundaries within Arizona, New Mexico, and Utah. The Navajo Nation has a land area of over 70,000 square kilometers. The Navajo Nation Department of Water Resources (NNDWR) reports on drought and climatic conditions through the use of regional Standardized Precipitation Index (SPI) values and a network of in-situ rainfall, streamflow, and climate data. However, these data sources lack the spatial detail and consistent measurements needed to provide a coherent understanding of the drought regime within the Nation's regional boundaries. This project, as part of NASA's Western Water Applications Office (WWAO), improves upon the recently developed Drought Severity Assessment Tool (DSAT) to ingest satellite-based precipitation data to generate SPI values for specific administrative boundaries within the reservation. The tool aims to: (1) generate SPI values and summary statistics for regions of interest on various timescales, (2) to visualize SPI values within a web-map application, and (3) produce maps and comparative statistical outputs in the format required for annual drought reporting. The co-development of the DSAT with NN partners is integral to increasing the sustained use of Earth Observations for water management applications. This tool will provide data to support the NN in allocation of drought contingency dollars to the regions most adversely impacted by declines in water availability.

Authigenic Carbonate Fans from Lower Jurassic Marine Shales (Alberta, Canada)

NASA Astrophysics Data System (ADS)

Martindale, R. C.; Them, T. R., II; Gill, B. C.; Knoll, A. H.

2016-12-01

Authigenic aragonite seafloor fans are a common occurrence in Archean and Paleoproterozoic carbonates, as well as Neoproterozoic cap carbonates. Similar carbonate fans are rare in Phanerozoic strata, with the exception of two mass extinction events; during the Permo-Triassic and Triassic-Jurassic boundaries, carbonate fans formed at the sediment-water interface and within the sediment, respectively. These crystal fans have been linked to carbon cycle perturbations at the end of the Permian and Triassic periods driven by rapid flood volcanism. The Early Jurassic Toarcian Ocean Anoxic Event (T-OAE) is also correlated with the emplacement of a large igneous province, but biological consequences were more modest. We have identified broadly comparable fibrous calcite layers (2-10 cm thick) in Pliensbachian-Toarcian cores from Alberta, Canada. This work focuses on the geochemical and petrographic description of these fans and surrounding sediment in the context of the T-OAE. At the macroscale, carbonates exhibit a fan-like (occasionally cone-in-cone) structure and displace the sediment around them as they grew. At the microscale, the carbonate crystals (pseudomorphs of aragonite) often initiate on condensed horizons or shells. Although they grow in multiple directions (growth within the sediment), the predominant crystal growth direction is towards the sediment-water interface. Resedimentation of broken fans is evidence that crystal growth was penecontemporaneous with sedimentation. The carbon isotope composition of the fans (transects up bladed crystals) and elemental abundances within the layers support shallow subsurface, microbially mediated growth. The resemblance of these Early Jurassic fibrous calcite layers to those found at the end-Triassic and their paucity in the Phanerozoic record suggest that analogous processes occurred at both events. Nevertheless, the Pliensbachian-Toarcian carbonate fans occur at multiple horizons and while some are within the T

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…

EPA Science Matters Newsletter: Working with Navajo Nation for Cleaner, Healthier Heat

EPA Pesticide Factsheets

EPA researchers and partners are teaming up to explore how to improve indoor air and health for Navajo Nation. Read about the results of the study and the proposed solutions to minimize indoor air pollution for the Navajo.

The ethical issues in uranium mining research in the Navajo Nation.

PubMed

Panikkar, Bindu; Brugge, Doug

2007-01-01

We explore the experience of Navajo communities living under the shadow of nuclear age fallout who were subjects of five decades of research. In this historical analysis of public health (epidemiological) research conducted in the Navajo lands since the inception of uranium mining from the 1950s untill the end of the 20th century, we analyze the successes and failures in the research initiatives conducted on Navajo lands, the ethical breaches, and the harms and benefits that this research has brought about to the community. We discuss how scientific and moral uncertainty, lack of full stakeholder participation and community wide outreach and education can impact ethical decisions made in research.

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…

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…

Environmental and ecological upheval in shallow marine systems during the Early Jurassic (Pliensbachian and Toarcian)

NASA Astrophysics Data System (ADS)

Martindale, R. C.; Ettinger, N. P.; Bodin, S.; Kosir, A.; Brame, H. M. R.; Thibodeau, A. M.; Larson, T. E.; Kerans, C.

2017-12-01

Carbon cycle perturbations, such as the Toarcian Oceanic Anoxic Event (T-OAE), have a significant influence on marine communities (e.g., extinctions), as well as the nature of the sedimentary record (e.g., carbonate factory collapse and black shale deposition) and geochemical cycling. To date, there remains a gap in our knowledge about the shallow-water record of the T-OAE and the geochemical signature of this event. This research combines geochemical, sedimentological, and paleontological data from two shallow-water Early Jurassic records in Slovenia and Morocco. The Dinaric Carbonate Platform (Slovenia) records a relatively continuous record of Pliensbachian and Toarcian strata and captures the T-OAE in shallow-water carbonates. The Trnovski Gozd karst plateau (western Slovenia) contains Pleinsbachian lithiotid (bivalve) biostromes, coral bioherms, and a diverse assemblage of carbonate producing fauna. This work documents the geochemical and sedimentological signature of the T-OAE in shallow water carbonates and tests whether mercury concentrations link paleontological and sedimentological changes with the Karoo-Ferrar Large Igneous Province. Elemental data coupled with sedimentologic and stratigraphic evidence indicate a prolonged period of deoxygenation on the shelf coincident with both large igneous province activity and the OAE. The Moroccan High Atlas Mountains provide another excellent shallow-water record of the T-OAE, with a thick mixed carbonate-siliciclastic shelf-to-ramp setting with sustained deposition through the Early Jurassic interval. In Morocco there is no evidence for anoxia in this shallow-water locality; however, the carbonate factory collapses at the Pliensbachian-Toarcian stage boundary as well as the T-OAE. Reef communities, particularly the lithiotid biostromes, persist across the stage boundary and are observed through to the T-OAE. The studied localities also record the oldest corals reefs following the T-OAE; coral reefs recover

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.

Nutrition-based interventions to address metabolic syndrome in the Navajo: a systematic review.

PubMed

Nava, Lorenzo T; Zambrano, Jenelle M; Arviso, Karen P; Brochetti, Denise; Becker, Kathleen L

2015-11-01

The objective of this systematic review is to identify nutrition-based interventions that may be effective for the prevention and treatment of metabolic syndrome in the Navajo. Metabolic syndrome, a major risk factor for cardiovascular disease, affects almost half of the Navajo population. The diet of the Navajo, heavy in fat and refined carbohydrates, has been identified as an important contributing factor to the high rates of metabolic syndrome in this population. A search was conducted on PubMed, EMBASE and CINAHL to identify studies published before October, 2013, involving nutrition-based interventions in adult populations similar to the Navajo targeting at least one measure of metabolic syndrome. Data on efficacy and participation were gathered and synthesised qualitatively. Out of 19 studies included in this systematic review, 11 interventions were identified to be effective at improving at least one measure of metabolic syndrome. Level of exposure to the intervention, frequency of intervention activities, family and social support, cultural adaptation and case management were identified as factors that may improve the efficacy of an intervention. Multiple nutrition-based interventions have been found to be effective in populations similar to the Navajo. Development of a strategy to address metabolic syndrome in the Navajo may involve aspects from multiple interventions to increase efficacy and maximise participation. © 2015 John Wiley & Sons Ltd.

Saad Naakih Bee'enootiilji Na'alkaa: Restructuring the Teaching of Language and Literacy in a Navajo Community School.

ERIC Educational Resources Information Center

Dick, Galena Sells; And Others

1994-01-01

Describes the 10-year development of the Rough Rock English-Navajo Language Arts Program (RRENLAP) to improve the teaching of language, literacy, and biliteracy. Discusses collaboration between Rough Rock and the Hawaii-based Kamehameha Early Education Program, key RRENLAP instructional features, and the role of bilingual teachers in the struggle…

Rationale, design and methodology for the Navajo Health and Nutrition Survey.

PubMed

White, L L; Goldberg, H I; Gilbert, T J; Ballew, C; Mendlein, J M; Peter, D G; Percy, C A; Mokdad, A H

1997-10-01

As recently as 1990, there was no reservation-wide, population-based health status information about Navajo Indians. To remedy this shortcoming, the Navajo Health and Nutrition Survey was conducted from 1991 to 1992 to assess the health and nutritional status of Navajo Reservation residents using a population-based sample. Using a three-stage design, a representative sample of reservation households was selected for inclusion. All members of selected households 12 y of age and older were invited to participate. A total of 985 people in 459 households participated in the study. Survey protocols were modeled on those of previous national surveys and included a standard blood chemistry profile, complete blood count, oral glucose tolerance test, blood pressure, anthropometric measurements, a single 24-h dietary recall and a questionnaire on health behaviors. The findings from this survey, reported in the accompanying papers, inform efforts to prevent and control chronic disease among the Navajo. Lessons learned from this survey may be of interest to those conducting similar surveys in other American Indian and Alaska Native populations.

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…

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…

Basin geodynamics and sequence stratigraphy of Upper Triassic to Lower Jurassic deposits of Southern Tunisia

NASA Astrophysics Data System (ADS)

Carpentier, Cédric; Hadouth, Suhail; Bouaziz, Samir; Lathuilière, Bernard; Rubino, Jean-Loup

2016-05-01

Aims of this paper are to propose a geodynamic and sequential framework for the late Triassic and early Jurassic of and south Tunisia and to evidence the impact of local tectonics on the stratigraphic architecture. Facies of the Upper Triassic to Lower Jurassic of Southern Tunisia have been interpreted in terms of depositional environments. A sequential framework and correlation schemes are proposed for outcrops and subsurface transects. Nineteen middle frequency sequences inserted in three and a half low frequency transgression/regression cycles were evidenced. Despite some datation uncertainties and the unknown durations of Lower Jurassic cycles, middle frequency sequences appear to be controlled by eustasy. In contrast the tectonics acted as an important control on low frequency cycles. The Carnian flooding was certainly favored by the last stages of a rifting episode which started during the Permian. The regression accompanied by the formation of stacked angular unconformities and the deposition of lowstand deposits during the late Carnian and Norian occured during the uplift and tilting of the northern basin margins. The transpressional activity of the Jeffara fault system generated the uplift of the Tebaga of Medenine high from the late Carnian and led to the Rhaetian regional angular Sidi Stout Unconformity. Facies analysis and well-log correlations permitted to evidence that Rhaetian to Lower Jurassic Messaoudi dolomites correspond to brecciated dolomites present on the Sidi Stout unconformity in the North Dahar area. The Early-cimmerian compressional event is a possible origin for the global uplift of the northern African margin and Western Europe during the late Carnian and the Norian. During the Rhaetian and the early Jurassic a new episode of normal faulting occured during the third low frequency flooding. This tectonosedimentary evolution ranges within the general geodynamic framework of the north Gondwana margin controlled by the opening of both

Fossil Energy Planning for Navajo Nation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acedo, Margarita

This project includes fossil energy transition planning to find optimal solutions that benefit the Navajo Nation and stakeholders. The majority of the tribe’s budget currently comes from fossil energy-revenue. The purpose of this work is to assess potential alternative energy resources including solar photovoltaics and biomass (microalgae for either biofuel or food consumption). This includes evaluating carbon-based reserves related to the tribe’s resources including CO 2 emissions for the Four Corners generating station. The methodology for this analysis will consist of data collection from publicly available data, utilizing expertise from national laboratories and academics, and evaluating economic, health, and environmentalmore » impacts. Finally, this report will highlight areas of opportunities to implement renewable energy in the Navajo Nation by presenting the technology requirements, cost, and considerations to energy, water, and environment in an educational structure.« less

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)

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

First glimpse into Lower Jurassic deep-sea biodiversity: in situ diversification and resilience against extinction

PubMed Central

Thuy, Ben; Kiel, Steffen; Dulai, Alfréd; Gale, Andy S.; Kroh, Andreas; Lord, Alan R.; Numberger-Thuy, Lea D.; Stöhr, Sabine; Wisshak, Max

2014-01-01

Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemblage of echinoderms, gastropods, brachiopods and ostracods, from the Early Jurassic of the Glasenbach Gorge, Austria, which includes the oldest known representatives of a number of extant deep-sea groups, and thus implies that in situ diversification, in contrast to immigration from shelf habitats, played a much greater role in shaping modern deep-sea biodiversity than previously thought. A comparison with coeval shelf assemblages reveals that, at least in some of the analysed groups, significantly more extant families/superfamilies have endured in the deep sea since the Early Jurassic than in the shelf seas, which suggests that deep-sea biota are more resilient against extinction than shallow-water ones. In addition, a number of extant deep-sea families/superfamilies found in the Glasenbach assemblage lack post-Jurassic shelf occurrences, implying that if there was a complete extinction of the deep-sea fauna followed by replacement from the shelf, it must have happened before the Late Jurassic. PMID:24850917

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…

Palaeoclimatic conditions in the Late Triassic-Early Jurassic of southern Africa: A geochemical assessment of the Elliot Formation

NASA Astrophysics Data System (ADS)

Sciscio, Lara; Bordy, Emese M.

2016-07-01

The Triassic-Jurassic boundary marks a global faunal turnover event that is generally considered as the third largest of five major biological crises in the Phanerozoic geological record of Earth. Determining the controlling factors of this event and their relative contributions to the biotic turnover associated with it is on-going globally. The Upper Triassic and Lower Jurassic rock record of southern Africa presents a unique opportunity for better constraining how and why the biosphere was affected at this time not only because the succession is richly fossiliferous, but also because it contains important palaeoenvironmental clues. Using mainly sedimentary geochemical proxies (i.e., major, trace and rare earth elements), our study is the first quantitative assessment of the palaeoclimatic conditions during the deposition of the Elliot Formation, a continental red bed succession that straddles the Triassic-Jurassic boundary in southern Africa. Employing clay mineralogy as well as the indices of chemical alteration and compositional variability, our results confirm earlier qualitative sedimentological studies and indicate that the deposition of the Upper Triassic and Lower Jurassic Elliot Formation occurred under increasingly dry environmental conditions that inhibited chemical weathering in this southern part of Pangea. Moreover, the study questions the universal validity of those studies that suggest a sudden increase in humidity for the Lower Jurassic record and supports predictions of long-term global warming after continental flood basalt emplacement.

Geohydrology of the Navajo sandstone in western Kane, southwestern Garfield, and southeastern Iron counties, Utah

USGS Publications Warehouse

Freethey, G.W.

1988-01-01

The upper Navajo and Lamb Point aquifers in the Navajo Sandstone are the principal source of water for the city of Kanab, irrigation, stock, and for rural homes in the study area. Well logs and outcrop descriptions indicate the Navajo Sandstone consists of the Lamb Point Tongue and an unnamed upper member that are separated by the Tenney Canyon Tongue of the Kayenta Formation. The main Kayenta Formation underlies the Lamb Point Tongue. The Lamb Point Tongue and the upper member of the Navajo Sandstone are saturated and hydraulically connected through the Tenney Canyon Tongue. Available data indicate that precipitation percolates to the groundwater reservoir where the Navajo Sandstone crops out. Estimates of the rate of recharge at the outcrop range from 0.1 to as much as 2.8 in/yr. Water level data indicate that water moves from the upper member of the Navajo Sandstone, through the Tenney Canyon Tongue, and into the Lamb Point Tongue. Lateral flow is generally from the outcrop areas toward the incised canyons formed by tributaries of Kanab Creek and Johnson Wash. Direction and rate of groundwater movement and the location and character of the natural hydrologic boundaries in the northern part of the area where the Navajo Sandstone is buried cannot be determined conclusively without additional water level data. (Author 's abstract)

Survey of Navajo Community Studies, 1936-1974. Lake Powell Research Project Bulletin Number 6, March 1975.

ERIC Educational Resources Information Center

Henderson, Eric B.; Levy, Jerrold E.

Extant Navajo community studies conducted since the 1930's were surveyed. Data for selected social, economic, and demographic variables as reported in these studies were compared. Each community study was placed in one of three geographic classifications: western Navajo, eastern Navajo, and off-reservation. Each on-reservation area was subdivided…

Naalyehe Ba Hooghan--"House of Merchandise": The Navajo Trading Post as an Institution of Cultural Change, 1900 to 1930.

ERIC Educational Resources Information Center

McPherson, Robert S.

1992-01-01

Navajo Reservation trading posts held an influential position between two cultures and operated on Navajo terms but also were an assimilative force emphasizing white values through the marketing of Navajo wool and rugs, traffic in prehistoric artifacts, and employment of Navajos in a mixed barter and wage economy. (SV)

Navajo Philosophy of Learning and Pedagogy.

ERIC Educational Resources Information Center

Benally, Herbert John

1994-01-01

Describes Navajo philosophy and implications for teaching and learning. Explains four branches of knowing that provide a framework for conceptualizing teaching content, as well as interrelationships within the framework providing opportunities for critical analysis and reflection. Advocates inquiry-oriented, experience-based instruction that…

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

Biotic and environmental dynamics through the Late Jurassic-Early Cretaceous transition: evidence for protracted faunal and ecological turnover.

PubMed

Tennant, Jonathan P; Mannion, Philip D; Upchurch, Paul; Sutton, Mark D; Price, Gregory D

2017-05-01

The Late Jurassic to Early Cretaceous interval represents a time of environmental upheaval and cataclysmic events, combined with disruptions to terrestrial and marine ecosystems. Historically, the Jurassic/Cretaceous (J/K) boundary was classified as one of eight mass extinctions. However, more recent research has largely overturned this view, revealing a much more complex pattern of biotic and abiotic dynamics than has previously been appreciated. Here, we present a synthesis of our current knowledge of Late Jurassic-Early Cretaceous events, focusing particularly on events closest to the J/K boundary. We find evidence for a combination of short-term catastrophic events, large-scale tectonic processes and environmental perturbations, and major clade interactions that led to a seemingly dramatic faunal and ecological turnover in both the marine and terrestrial realms. This is coupled with a great reduction in global biodiversity which might in part be explained by poor sampling. Very few groups appear to have been entirely resilient to this J/K boundary 'event', which hints at a 'cascade model' of ecosystem changes driving faunal dynamics. Within terrestrial ecosystems, larger, more-specialised organisms, such as saurischian dinosaurs, appear to have suffered the most. Medium-sized tetanuran theropods declined, and were replaced by larger-bodied groups, and basal eusauropods were replaced by neosauropod faunas. The ascent of paravian theropods is emphasised by escalated competition with contemporary pterosaur groups, culminating in the explosive radiation of birds, although the timing of this is obfuscated by biases in sampling. Smaller, more ecologically diverse terrestrial non-archosaurs, such as lissamphibians and mammaliaforms, were comparatively resilient to extinctions, instead documenting the origination of many extant groups around the J/K boundary. In the marine realm, extinctions were focused on low-latitude, shallow marine shelf-dwelling faunas

Livestock grazing for management of reclaimed land at Navajo Mine: Animal response

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 ofmore » 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.« less

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

... Environmental Impact Statement (EIS) for the Navajo Nation Integrated Weed Management Plan Within Coconino...-year integrated weed management plan for the Navajo Indian Reservation. The Navajo Indian Reservation... integrated weed management plan include, but will not be limited to, mechanical, cultural, biological and...

Cycles and trends in the δ18O and δ13C records over the Jurassic and Early Cretaceous

NASA Astrophysics Data System (ADS)

Martinez, Mathieu; Dera, Guillaume

2015-04-01

The million-year fluctuations of the Mesozoic climate are explored through spectral analyses performed on an exhaustive compilation of δ18O and δ13C data measured on belemnite rostra. The data include more than 3500 data points, all coming from Western Tethys and Euro-boreal domains, and covering a time interval spanning 76 Myr from the Sinemurian (~197 Ma; Early Jurassic) to the Aptian (~123 Ma; Early Cretaceous) with an average sample step of ~0.04 Myr. Spectral analyses are performed using the multi-taper method and the evolutive Fast Fourier Transform in order to get an accurate estimate of significant periods and their evolution during geological times. The age uncertainties of the Geological Time Scale 2012 are taken into account to assess the impact of these uncertainties on the identification of the significant periods. After implementing an error model that simulates the uncertainties of the Geological Time Scale, two periods remains significant: the δ13C displays a high-amplitude period at 9.1 Myr, while the δ18O displays a high-amplitude period at 16.4 Myr. The 16.4-Myr period is only expressed in the Early and Middle Jurassic, with maximum amplitudes reached during the 'Toarcian Plateau' (Dera et al., 2011). It is probably a consequence of the activity of the Karoo-Ferrar Large Igneous Province and is an event in the δ18O rather than a true cycle. The 9.1-Myr period displays a spectacular continuity from the Toarcian to the Aptian, and could be related to this intriguing 9.1-Myr cycle observed in the δ13C from the Cenozoic, related to a Myr-amplitude modulation of the eccentricity cycles (Boulila et al., 2012). The δ13C in the Western Tethys thus appears to have a very rhythmic behaviour, interpreted here as a long-term orbital modulation of moisture and heat transfer from equatorial to higher latitudes, modulating in return continental weathering, nutrient and detrital exports to basins, neritic vs. pelagic productivity and finally preservation

Evolutionary and Ecological Sequelae of Mass Extinctions: Examples From the Continental Triassic-Jurassic Boundary

NASA Astrophysics Data System (ADS)

Olsen, P. E.; Whiteside, J. H.

2003-12-01

after the boundary. Species flocks of semionotid fishes dominated earliest Jurassic giant rift lakes in eastern North America, but not Triassic or later Early Jurassic lakes in the same basins. Based on footprint data, it is quite possible that there were also species flocks of morphologically similar ceratosaurian theropod dinosaurs in the Early Jurassic.

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…

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…

Florida: A Jurassic transform plate boundary

USGS Publications Warehouse

Klitgord, Kim D.; Popenoe, Peter; Schouten, Hans

1984-01-01

Magnetic, gravity, seismic, and deep drill hole data integrated with plate tectonic reconstructions substantiate the existence of a transform plate boundary across southern Florida during the Jurassic. On the basis of this integrated suite of data the pre-Cretaceous Florida-Bahamas region can be divided into the pre-Jurassic North American plate, Jurassic marginal rift basins, and a broad Jurassic transform zone including stranded blocks of pre-Mesozoic continental crust. Major tectonic units include the Suwannee basin in northern Florida containing Paleozoic sedimentary rocks, a central Florida basement complex of Paleozoic age crystalline rock, the west Florida platform composed of stranded blocks of continental crust, the south Georgia rift containing Triassic sedimentary rocks which overlie block-faulted Suwannee basin sedimentary rocks, the Late Triassic-Jurassic age Apalachicola rift basin, and the Jurassic age south Florida, Bahamas, and Blake Plateau marginal rift basins. The major tectonic units are bounded by basement hinge zones and fracture zones (FZ). The basement hinge zone represents the block-faulted edge of the North American plate, separating Paleozoic and older crustal rocks from Jurassic rifted crust beneath the marginal basins. Fracture zones separate Mesozoic marginal sedimentary basins and include the Blake Spur FZ, Jacksonville FZ, Bahamas FZ, and Cuba FZ, bounding the Blake Plateau, Bahamas, south Florida, and southeastern Gulf of Mexico basins. The Bahamas FZ is the most important of all these features because its northwest extension coincides with the Gulf basin marginal fault zone, forming the southern edge of the North American plate during the Jurassic. The limited space between the North American and the South American/African plates requires that the Jurassic transform zone, connecting the Central Atlantic and the Gulf of Mexico spreading systems, was located between the Bahamas and Cuba FZ's in the region of southern Florida. Our

Advancing smoke-free policy adoption on the Navajo Nation.

PubMed

Nez Henderson, Patricia; Roeseler, April; Moor, Gregg; Clark, Hershel W; Yazzie, Alfred; Nez, Priscilla; Nez, Chantal; Sabo, Samantha; Leischow, Scott J

2016-10-01

Comprehensive smoke-free laws are effective at protecting non-smokers and reducing tobacco use, yet they are not widely adopted by tribal governments. A series of smoke-free policy initiatives on the Navajo Nation, beginning in 2008, were reviewed to identify key issues, successes and setbacks. It has been essential that proposed policies acknowledge the Navajo people's spiritual use of nát'oh, a sacred plant used for gift-giving, medicinal purposes and traditional ceremonies, while simultaneously discouraging a secular use of commercial tobacco. Concern that smoke-free policies economically harm tribal casinos has been a major barrier to broad implementation of comprehensive smoke-free laws in Navajo Nation. It is necessary for tobacco control researchers and advocates to build relationships with tribal leaders and casino management in order to develop the business case that will take comprehensive smoke-free policies to scale throughout tribal lands. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

"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…

Late Jurassic-Early Cretaceous episodic development of the Bangong Meso-Tethyan subduction: Evidence from elemental and Sr-Nd isotopic geochemistry of arc magmatic rocks, Gaize region, central Tibet, China

NASA Astrophysics Data System (ADS)

Zhang, Yu-Xiu; Li, Zhi-Wu; Yang, Wen-Guang; Zhu, Li-Dong; Jin, Xin; Zhou, Xiao-Yao; Tao, Gang; Zhang, Kai-Jun

2017-03-01

The Bangong Meso-Tethys plays a critical role in the development of the Tethyan realm and the initial elevation of the Tibetan Plateau. However, its precise subduction polarity, and history still remain unclear. In this study, we synthesize a report for the Late Jurassic-Early Cretaceous two-phase magmatic rocks in the Gaize region at the southern margin of the Qiangtang block located in central Tibet. These rocks formed during the Late Jurassic-earliest Cretaceous (161-142 Ma) and Early Cretaceous (128-106 Ma), peaking at 146 Ma and 118 Ma, respectively. The presence of inherited zircons indicates that an Archean component exists in sediments in the shallow Qiangtang crust, and has a complex tectonomagmatic history. Geochemical and Sr-Nd isotopic data show that the two-phase magmatic rocks exhibit characteristics of arc magmatism, which are rich in large-ion incompatible elements (LIIEs), but are strongly depleted in high field strength elements (HFSEs). The Late Jurassic-earliest Cretaceous magmatic rocks mixed and mingled among mantle-derived mafic magmas, subduction-related sediments, or crustally-derived felsic melts and fluids, formed by a northward and steep subduction of the Bangong Meso-Tethys ocean crust. The magmatic gap at 142-128 Ma marks a flat subduction of the Meso-Tethys. The Early Cretaceous magmatism experienced a magma MASH (melting, assimilation, storage, and homogenization) process among mantle-derived mafic magmas, or crustally-derived felsic melts and fluids, as a result of the Meso-Tethys oceanic slab roll-back, which triggered simultaneous back-arc rifting along the southern Qiangtang block margin.

Evolution of the Toarcian (Early Jurassic) carbon-cycle and global climatic controls on local sedimentary processes (Cardigan Bay Basin, UK)

NASA Astrophysics Data System (ADS)

Xu, Weimu; Ruhl, Micha; Jenkyns, Hugh C.; Leng, Melanie J.; Huggett, Jennifer M.; Minisini, Daniel; Ullmann, Clemens V.; Riding, James B.; Weijers, Johan W. H.; Storm, Marisa S.; Percival, Lawrence M. E.; Tosca, Nicholas J.; Idiz, Erdem F.; Tegelaar, Erik W.; Hesselbo, Stephen P.

2018-02-01

The late Early Jurassic Toarcian Stage represents the warmest interval of the Jurassic Period, with an abrupt rise in global temperatures of up to ∼7 °C in mid-latitudes at the onset of the early Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma). The T-OAE, which has been extensively studied in marine and continental successions from both hemispheres, was marked by the widespread expansion of anoxic and euxinic waters, geographically extensive deposition of organic-rich black shales, and climatic and environmental perturbations. Climatic and environmental processes following the T-OAE are, however, poorly known, largely due to a lack of study of stratigraphically well-constrained and complete sedimentary archives. Here, we present integrated geochemical and physical proxy data (high-resolution carbon-isotope data (δ13 C), bulk and molecular organic geochemistry, inorganic petrology, mineral characterisation, and major- and trace-element concentrations) from the biostratigraphically complete and expanded entire Toarcian succession in the Llanbedr (Mochras Farm) Borehole, Cardigan Bay Basin, Wales, UK. With these data, we (1) construct the first high-resolution biostratigraphically calibrated chemostratigraphic reference record for nearly the complete Toarcian Stage, (2) establish palaeoceanographic and depositional conditions in the Cardigan Bay Basin, (3) show that the T-OAE in the hemipelagic Cardigan Bay Basin was marked by the occurrence of gravity-flow deposits that were likely linked to globally enhanced sediment fluxes to continental margins and deeper marine (shelf) basins, and (4) explore how early Toarcian (tenuicostatum and serpentinum zones) siderite formation in the Cardigan Bay Basin may have been linked to low global oceanic sulphate concentrations and elevated supply of iron (Fe) from the hinterland, in response to climatically induced changes in hydrological cycling, global weathering rates and large-scale sulphide and evaporite deposition.

Deep burial dolomitization driven by plate collision: Evidence from strontium-isotopes of Jurassic Arab IV dolomites from offshore Qatar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vahrenkamp, V.C.; Taylor, S.R.

The use of strontium-isotope ratios of dolomites to constrain timing and mechanism of diagenesis has been investigated on Jurassic Arab IV dolomites from offshore Qatar. Reservoir quality is determined by two types of dolomites, which were differentiated geochemically (cathodoluminescence, fluid inclusions, and carbon and oxygen stable isotopes): (1) stratigraphically concordant sucrosic dolomites with high porosity formed during early near-surface diagenesis (Jurassic) and (2) stratigraphically discordant cylindrical bodies of massive, porosity-destroying dolomites formed late during deep burial diagenesis (Eocene-Pliocene). Detailed Sr-isotope analysis of dolomites from the Arab IV confirms an Early Jurassic age of the sucrosic, high porosity dolomites ({sup 87}Sr/{supmore » 86}SR = 0.70707 for NBS 987 = 0.71024) with magnesium and strontium being derived from Jurassic seawater. Late Tertiary compressional orogeny of the Zagros belt to the north is proposed to have caused large-scale squeezing of fluids from the pore system of sedimentary rocks. A regional deep fluid flow system developed dissolving infra-Cambrian evaporites upflow and causing large-scale deep burial dolomitization downflow.« less

Tectono-stratigraphy and low-grade metamorphism of Late Permian and Early Jurassic accretionary complexes within the Kurosegawa belt, Southwest Japan: Implications for mechanisms of crustal displacement within active continental margin

NASA Astrophysics Data System (ADS)

Hara, Hidetoshi; Kurihara, Toshiyuki; Mori, Hiroshi

2013-04-01

We characterize the tectono-stratigraphic architecture and low-grade metamorphism of the accretionary complex preserved in the Kurosegawa belt of the Kitagawa district in eastern Shikoku, Southwest Japan, in order to understand its internal structure, tectono-metamorphic evolution, and assessments of displacement of continental fragments within the complex. We report the first ever documented occurrence of an Early Jurassic radiolarian assemblage within the accretionary complex of the Kurosegawa belt that has been previously classified as the Late Permian accretionary complex, thus providing a revised age interpretation for these rocks. The accretionary complex is subdivided into four distinct tectono-stratigraphic units: Late Permian mélange and phyllite units, and Early Jurassic mélange and sandstone units. The stratigraphy of these four units is structurally repeated due to an E-W striking, steeply dipping regional fault. We characterized low-grade metamorphism of the accretionary complex via illite crystallinity and Raman spectroscopy of carbonaceous material. The estimated pattern of low-grade metamorphism showed pronounced variability within the complex and revealed no discernible spatial trends. The primary thermal structure in these rocks was overprinted by later tectonic events. Based on geological and thermal structure, we conclude that continental fragments within the Kurosegawa belt were structurally translated into both the Late Permian and Early Jurassic accretionary complexes, which comprise a highly deformed zone affected by strike-slip tectonics during the Early Cretaceous. Different models have been proposed to explain the initial structural evolution of the Kurosegawa belt (i.e., micro-continent collision and klippe tectonic models). Even if we presuppose either model, the available geological evidence requires a new interpretation, whereby primary geological structures are overprinted and reconfigured by later tectonic events.

Sedimentary record of subsidence pulse at the Triassic/Jurassic boundary interval in the Slovenian Basin (eastern Southern Alps)

NASA Astrophysics Data System (ADS)

Rožič, Boštjan; Jurkovšek, Tea Kolar; Rožič, Petra Žvab; Gale, Luka

2017-08-01

In the Alpine Realm the Early Jurassic is characterized by the disintegration and partial drowning of vast platform areas. In the eastern part of the Southern Alps (present-day NW Slovenia), the Julian Carbonate Platform and the adjacent, E-W extending Slovenian Basin underwent partial disintegration, drowning and deepening from the Pliensbachian on, whereas only nominal environmental changes developed on the large Dinaric (Friuli, Adriatic) Carbonate Platform to the south (structurally part of the Dinarides). These events, however, were preceded by an earlier - and as yet undocumented extensional event - that took place near the Triassic/Jurassic boundary. This paper provides evidence of an accelerated subsidence from four selected areas within the Slovenian Basin, which show a trend of eastwardly-decreasing deformation. In the westernmost (Mrzli vrh) section - the Upper Triassic platform-margin - massive dolomite is overlain by the earliest Jurassic toe-of-slope carbonate resediments and further, by basin-plain micritic limestone. Further east (Perbla and Liščak sections) the Triassic-Jurassic transition interval is marked by an increase in resedimented carbonates. We relate this to the increasing inclination and segmentation of the slope and adjacent basin floor. The easternmost (Mt. Porezen) area shows a rather monotonous, latest Triassic-Early Jurassic basinal sedimentation. However, changes in the thickness of the Hettangian-Pliensbachian Krikov Formation point to a tilting of tectonic blocks within the basin area. Lateral facies changes at the base of the formation indicate that the tilting occurred at and/or shortly after the Triassic/Jurassic boundary

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…

Geomagnetic Reversals of the Late Jurassic and Early Cretaceous Captured in a North China Core

NASA Astrophysics Data System (ADS)

Kuhn, T.; Fu, R. R.; Kent, D. V.; Olsen, P. E.

2016-12-01

The Tuchengzi formation in North China nominally spans nearly 20 million years of the Late Jurassic and Early Cretaceous, an interval during which age calibration of the Geomagnetic Polarity Time Scale (GPTS) based on seafloor magnetic anomalies is poorly known. The overlying Yixian formation is of special paleontological interest due to an abundance of spectacularly preserved macrofossils of feathered non-avian dinosaurs, birds, mammals, and insects. Scarce fossils in the Tuchengzi, sparse accurate radiometric dates on both the Tuchengzi and overlying Yixian formation, and scant previous paleomagnetic studies on these formations motivated our application of magnetostratigraphy as a geochronological tool. We constructed a geomagnetic reversal sequence from the upper 142m of a 200m core extracted in Liaoning Province at Huangbanjigou spanning the lower Yixian Formation and the unconformably underlying Tuchengzi Formation. Thermal demagnetization up to 680°C in steps of 25-50°C revealed predominantly normal overprints consistent with the modern day field with unblocking temperatures between 125°C and as high as 550°C, as well as normal and reverse characteristic components with unblocking temperatures between 500°C and 680°C. Going up from the base of the core, there is a reverse polarity magnetozone >6m thick, followed by a 5m normal magnetozone, a 10m reverse magnetozone, a 25m normal magnetozone, and a 6m reverse magnetozone truncated by the Yixian-Tuchengzi unconformity. Above the unconformity, all 81m of core were normal. These results indicate that a meaningful polarity stratigraphy can be recovered from the Tuchengzi and Yixian formations that will be invaluable for correlations across the Tuchengzi and potentially the Yixian formations, which span thousands of square kilometers and vary in thickness by many hundreds of meters. The results also demonstrate that, in combination with accurate and precise radiometric dates, the Tuchengzi Formation has the

Toward establishing a definitive Late-Mid Jurassic (M-series) Geomagnetic Polarity Reversal Time Scale through unraveling the nature of Jurassic Quiet Zone.

NASA Astrophysics Data System (ADS)

Tominaga, M.; Tivey, M.; Sager, W.

2017-12-01

Two major difficulties have hindered improving the accuracy of the Late-Mid Jurassic geomagnetic polarity time scale: a dearth of reliable high-resolution radiometric dates and the lack of a continuous Jurassic geomagnetic polarity time scale (GPTS) record. We present the latest effort towards establishing a definitive Mid Jurassic to Early Cretaceous (M-series) GPTS model using three high-resolution, multi-level (sea surface [0 km], mid-water [3 km], and near-source [5.2 km]) marine magnetic profiles from a seamount-free corridor adjacent to the Waghenaer Fracture Zone in the western Pacific Jurassic Quiet Zone (JQZ). The profiles show a global coherency in magnetic anomaly correlations between two mid ocean ridge systems (i.e., Japanese and Hawaiian lineations). Their unprecedented high data resolution documents a detailed anomaly character (i.e., amplitudes and wavelengths). We confirm that this magnetic anomaly record shows a coherent anomaly sequence from M29 back in time to M42 with previously suggested from the Japanese lineation in the Pigafetta Basin. Especially noticeable is the M39-M41 Low Amplitude Zone defined in the Pigafetta Bsin, which potentially defines the bounds of JQZ seafloor. We assessed the anomaly source with regard to the crustal architecture, including the effects of Cretaceous volcanism on crustal magnetization and conclude that the anomaly character faithfully represents changes in geomagnetic field intensity and polarity over time and is mostly free of any overprint of the original Jurassic magnetic remanence by later Cretaceous volcanism. We have constructed polarity block models (RMS <5 nT [normalized] between observed and calculated profiles) for each of the survey lines, yielding three potential GPTS candidate models with different source-to-sensor resolutions, from M19-M38, which can be compared to currently available magnetostratigraphic records. The overall polarity reversal rates calculated from each of the models are

Adapting a Cancer Literacy Measure for Use among Navajo Women

PubMed Central

Yost, Kathleen J.; Bauer, Mark C.; Buki, Lydia P.; Austin-Garrison, Martha; Garcia, Linda V.; Hughes, Christine A.; Patten, Christi A.

2016-01-01

Purpose The authors designed a community-based participatory research study to develop and test a family-based behavioral intervention to improve cancer literacy and promote mammography among Navajo women. Methods Using data from focus groups and discussions with a community advisory committee, they adapted an existing questionnaire to assess cancer knowledge, barriers to mammography, and cancer beliefs for use among Navajo women. Questions measuring health literacy, numeracy, self-efficacy, cancer communication, and family support were also adapted. Results The resulting questionnaire was found to have good content validity, and to be culturally and linguistically appropriate for use among Navajo women. Conclusions It is important to consider culture and not just language when adapting existing measures for use with AI/AN populations. English-language versions of existing literacy measures may not be culturally appropriate for AI/AN populations, which could lead to a lack of semantic, technical, idiomatic, and conceptual equivalence, resulting in misinterpretation of study outcomes. PMID:26879319

Adapting a Cancer Literacy Measure for Use Among Navajo Women.

PubMed

Yost, Kathleen J; Bauer, Mark C; Buki, Lydia P; Austin-Garrison, Martha; Garcia, Linda V; Hughes, Christine A; Patten, Christi A

2017-05-01

The authors designed a community-based participatory research study to develop and test a family-based behavioral intervention to improve cancer literacy and promote mammography among Navajo women. Using data from focus groups and discussions with a community advisory committee, they adapted an existing questionnaire to assess cancer knowledge, barriers to mammography, and cancer beliefs for use among Navajo women. Questions measuring health literacy, numeracy, self-efficacy, cancer communication, and family support were also adapted. The resulting questionnaire was found to have good content validity, and to be culturally and linguistically appropriate for use among Navajo women. It is important to consider culture and not just language when adapting existing measures for use with AI/AN (American Indian/Alaskan Native) populations. English-language versions of existing literacy measures may not be culturally appropriate for AI/AN populations, which could lead to a lack of semantic, technical, idiomatic, and conceptual equivalence, resulting in misinterpretation of study outcomes.

Inter-layered clay stacks in Jurassic shales

NASA Technical Reports Server (NTRS)

Pye, K.; Krinsley, D. H.

1983-01-01

Scanning electron microscopy in the backscattered electron mode is used together with energy-dispersive X-ray microanalysis to show that Lower Jurassic shales from the North Sea Basin contain large numbers of clay mineral stacks up to 150 microns in size. Polished shale sections are examined to determine the size, shape orientation, textural relationships, and internal compositional variations of the clays. Preliminary evidence that the clay stacks are authigenic, and may have formed at shallow burial depths during early diagenesis, is presented.

Risk factors for conduct disorder among Navajo Indian men and women.

PubMed

Kunitz, S J; Gabriel, K R; Levy, J E; Henderson, E; Lampert, K; McCloskey, J; Quintero, G; Russell, S; Vince, A

1999-04-01

To describe the risk factors for conduct disorder before age 15 among Navajo Indians. The study was based on a survey of a stratified random sample of adult Navajo Indians between the ages of 21 and 65 living on and adjacent to two different areas of the Navajo Reservation. There were 531 male and 203 female respondents. The average age (SD) of the men was 38.7 (10.5) years and of the women 35.5 (9.0) years. Conduct disorder was diagnosed retrospectively using the Diagnostic Interview Schedule first developed for the Epidemiological Catchment Area study. The responses were combined into a continuous scale. Significant risk factors for increased scores on the conduct disorder scale were: histories of physical and sexual abuse in childhood; abusive maternal drinking; a small number of households per camp; younger age; and being male rather than female. Measures of social status and religion in which subjects were raised were not significant. Many of the risk factors that are associated with conduct disorder in other populations are also risk factors in the Navajo population. There is suggestive evidence that some of these risk factors have become more common since World War II, raising the possibility that conduct disorder has become more prevalent, as is thought to be the case nationwide.

Multi-stage metamorphism in the South Armenian Block during the Late Jurassic to Early Cretaceous: Tectonics over south-dipping subduction of Northern branch of Neotethys

NASA Astrophysics Data System (ADS)

Hässig, M.; Rolland, Y.; Sahakyan, L.; Sosson, M.; Galoyan, G.; Avagyan, A.; Bosch, D.; Müller, C.

2015-04-01

The geologic evolution of the South Armenian Block (SAB) in the Mesozoic is reconstructed from a structural, metamorphic, and geochronologic study including U-Pb and 40Ar/39Ar dating. The South Armenian Block Crystalline Basement (SABCB) outcrops solely in a narrow tectonic window, NW of Yerevan. The study of this zone provides key and unprecedented information concerning closing of the Northern Neotethys oceanic domain north of the Taurides-Anatolides platform from the Middle Jurassic to the Early Cretaceous. The basement comprises of presumed Proterozoic orthogneiss overlain by metamorphosed pelites as well as intrusions of granodiorite and leucogranite during the Late Jurassic and Early Cretaceous. Structural, geochronological and petrological observations show a multiphased evolution of the northern margin of the SAB during the Late Jurassic and Early Cretaceous. A south-dipping subduction under the East Anatolian Platform-South Armenian Block (EAP-SAB) is proposed in order to suit recent findings pertaining emplacement of relatively hot subduction related granodiorite as well as the metamorphic evolution of the crystalline basement in the Lesser Caucasus area. The metamorphism is interpreted as evidencing: (1) M1 Barrovian MP-MT conditions (staurolite-kyanite) at c. 157-160 Ma and intrusion of dioritic magmas at c. 150-156 Ma, (2) near-adiabatic decompression is featured by partial melting and production of leucogranites at c. 153 Ma, followed by M2 HT-LP conditions (andalusite-K-feldspar). A phase of shearing and recrystallization is ascribed to doming at c. 130-150 Ma and cooling at 400 °C by c. 123 Ma (M3). Structural observations show (1) top to the north shearing during M1 and (2) radial extension during M2. The extensional event ends by emplacement of a thick detrital series along radial S, E and W-dipping normal faults. Further, the crystalline basement is unconformably covered by Upper Cretaceous-Paleocene series dated by nannofossils, evolving from

Navajo Nation: Cleaning Up Abandoned Uranium Mines

EPA Pesticide Factsheets

This site provides information about the progress of EPA's cleanup of abandoned uranium mines on Navajo and Hopi lands and in other areas of Arizona and New Mexico, including health impacts, major enforcement and removal milestones, and community actions.

Weight, body image, and weight control practices of Navajo Indians: findings from the Navajo Health and Nutrition Survey.

PubMed

White, L L; Ballew, C; Gilbert, T J; Mendlein, J M; Mokdad, A H; Strauss, K F

1997-10-01

Historically, the Navajo exhibited a low prevalence of overweight, but a number of small studies over the past few decades indicate that the prevalence is increasing. In the population-based Navajo Health and Nutrition Survey conducted in 1991-92, overweight was defined as a body mass index (BMI, kg/m2) at or above the 85th percentile (BMI > 27.8 for men, > 27.3 for women) of the Second National Health and Nutrition Examination Survey. One third of men age 20 and 39 and one half of men age 40 and 59, but fewer than 10% of men age 60 and older were overweight. Two thirds or more of women in all age groups were overweight. Nineteen percent of the participants underestimated their weight status (underweight, appropriate, overweight) relative to their BMI category and 17% overestimated their weight status. Women overestimated their weight status more often than men (P < 0.05), and participants age 20-39 overestimated their weight status more often than older participants (P < 0.001). Men and women age 60 and older preferred heavier body shape models as ideals of health more often than younger participants (P < 0.001). Nearly half of the participants, regardless of their weight status, reported that they were trying to lose weight; most reported using diet and exercise. Because overweight is an important risk factor for many chronic diseases, including diabetes mellitus, cardiovascular disease and cancer, primary prevention of overweight and weight management for adults are recommended to prevent an increase in the burden of chronic disease among the Navajo.

75 FR 4410 - Renewal of Agency Information Collection for Navajo Partitioned Lands Grazing Regulations Permits

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

... Control Number 1076-0162, which expires March 31, 2010. The information collection requires the Navajo... guarantee that we will be able to do so. III. Data OMB Control Number: 1076-0162. Title: Navajo Partitioned...

Oldest known dinosaurian nesting site and reproductive biology of the Early Jurassic sauropodomorph Massospondylus

PubMed Central

Reisz, Robert R.; Evans, David C.; Roberts, Eric M.; Sues, Hans-Dieter; Yates, Adam M.

2012-01-01

The extensive Early Jurassic continental strata of southern Africa have yielded an exceptional record of dinosaurs that includes scores of partial to complete skeletons of the sauropodomorph Massospondylus, ranging from embryos to large adults. In 1976 an incomplete egg clutch including in ovo embryos of this dinosaur, the oldest known example in the fossil record, was collected from a road-cut talus, but its exact provenance was uncertain. An excavation program at the site started in 2006 has yielded multiple in situ egg clutches, documenting the oldest known dinosaurian nesting site, predating other similar sites by more than 100 million years. The presence of numerous clutches of eggs, some of which contain embryonic remains, in at least four distinct horizons within a small area, provides the earliest known evidence of complex reproductive behavior including site fidelity and colonial nesting in a terrestrial vertebrate. Thus, fossil and sedimentological evidence from this nesting site provides empirical data on reproductive strategies in early dinosaurs. A temporally calibrated optimization of dinosaurian reproductive biology not only demonstrates the primary significance of the Massospondylus nesting site, but also provides additional insights into the initial stages of the evolutionary history of dinosaurs, including evidence that deposition of eggs in a tightly organized single layer in a nest evolved independently from brooding. PMID:22308330

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

If Not Us, Then Who? Increasing Opportunities for Students at Navajo Technical University

ERIC Educational Resources Information Center

Vandever, Daniel

2017-01-01

Navajo Technical University first opened its doors in 1979 as the Navajo Skills Center with the simple intention of training an unemployed workforce and putting people to work. At the time, the Diné were just a generation removed from attempts at forced assimilation, which included unwarranted military action by the U.S. Cavalry during the Long…

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 the...

Linking farmers to community stores to increase consumption of local produce: a case study of the Navajo Nation.

PubMed

Setala, Ashley; Gittelsohn, Joel; Speakman, Kristen; Oski, Jane; Martin, Tammy; Moore, Regina; Tohannie, Marcella; Bleich, Sara N

2011-09-01

To understand the barriers to farmer participation in Farm-to-Table (F2T) programmes and to identify possible solutions to these obstacles. Cross-sectional analysis of farmer perspectives on F2T programmes. Three service units on the Navajo Nation (Chinle, Tuba City and Fort Defiance). Forty-four Navajo farmers. Most participants reported that farming on the Navajo Nation is getting harder (61 %) but that it is very important to maintain Navajo farming traditions (98 %). A modest number of farmers (43 %) expressed interest in participating in an F2T programme. All farmers reported that childhood obesity was a very serious or serious problem in the Navajo Nation. The farmers expressed support for an F2T programme if key barriers to farming, including water access and pest control, could be addressed. Key barriers to participation identified included lack of fruits and vegetables to sell, sale price of crops and lack of certification of produce by the US Food and Drug Administration. Navajo farmers are aware of the burden of childhood obesity on the Navajo Nation and feel that an F2T programme could be beneficial. To successfully implement a Farm-to-Table programme, the barriers to participation identified will need to be addressed.

A Bibliography of Navajo and Native American Teaching Materials = Dine K'eeji Naaltsoos Bee Nida'nitinigii. Revised Edition.

ERIC Educational Resources Information Center

McCarty, T. L., Comp.; And Others

A revised annotated bibliography of Navajo and Native American teaching materials published between 1910 and 1982 (most from 1970 to 1982), compiled as part of the Title IV-B Navajo Materials Development Project, lists resources for teachers of Navajo and other Native American students. Most citations are of written materials, although some…

A source-depleted Early Jurassic granitic pluton from South China: Implication to the Mesozoic juvenile accretion of the South China crust

NASA Astrophysics Data System (ADS)

Zhou, Zuo-Min; Ma, Chang-Qian; Wang, Lian-Xun; Chen, Shu-Guang; Xie, Cai-Fu; Li, Yong; Liu, Wei

2018-02-01

Source-depleted granites were rarely reported in South China. Hereby we identified such a granitic pluton, the Tiandong pluton, at Northeastern Guangdong province in Southeastern (SE) China. Whole-rock Sr-Nd and zircon Hf isotopes of the Tiandong granites both revealed obviously depleted source signatures, with initial isotopic values of initial 87Sr/86Sr = 0.7032-0.7040, εNd(t) = 1.1-1.5, and εHf(t) = 6-13, respectively. Zircon U-Pb dating implied the granite was intruded in Early Jurassic (188 Ma). The dominant minerals of the Tiandong granite consist of K-feldspar, plagioclase, quartz and biotite, with accessory mineral assemblage of apatite + zircon + magnetite. Based on the mineralogy and the depleted isotopic signature, the granites chemically show I-type affinity such as low Zr + Nb + Ce + Y (131.6 to 212.2), 104 × Ga/Al (2.12-2.27), A/CNK values < 1.1 (0.97-1.03), corundum molecule < 1 (0-0.55) and extremely low P2O5 contents (0.05 wt%). The one-stage and two-stage depleted mantle Nd model ages (TDM = 0.89 to 0.84 Ga, T2DM = 0.88 to 0.85 Ga) are consistent. TDM(Hf) values of 0.31-0.63 Ga are also indistinguishable from T2DM(Hf) values of 0.35-0.75 Ga. The Nd and Hf isotopic compositions confirm that the Tiandong granites are juvenile crustal accretion but decoupled Nd-Hf isotopic systems. The juvenile crust is likely to originate from a mixed source of the primary asthenospheric mantle and the subordinate EMII. Combined with early studies of adjacent rocks, we propose that the early Jurassic ( 200-175 Ma) magmatism as evidenced by the Tiandong granites might be driven by upwelling of asthenosphere and subsequent underplating of mafic melts in an intra-plate extensional setting as a response to far-field stress during early stage subduction of the paleo-pacific plate.

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…

A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers

NASA Astrophysics Data System (ADS)

Lefèvre, Ulysse; Cau, Andrea; Cincotta, Aude; Hu, Dongyu; Chinsamy, Anusuya; Escuillié, François; Godefroit, Pascal

2017-10-01

Genuine fossils with exquisitely preserved plumage from the Late Jurassic and Early Cretaceous of northeastern China have recently revealed that bird-like theropod dinosaurs had long pennaceous feathers along their hindlimbs and may have used their four wings to glide or fly. Thus, it has been postulated that early bird flight might initially have involved four wings (Xu et al. Nature 421:335-340, 2003; Hu et al. Nature 461:640-643, 2009; Han et al. Nat Commun 5:4382, 2014). Here, we describe Serikornis sungei gen. et sp. nov., a new feathered theropod from the Tiaojishan Fm (Late Jurassic) of Liaoning Province, China. Its skeletal morphology suggests a ground-dwelling ecology with no flying adaptations. Our phylogenetic analysis places Serikornis, together with other Late Jurassic paravians from China, as a basal paravians, outside the Eumaniraptora clade. The tail of Serikornis is covered proximally by filaments and distally by slender rectrices. Thin symmetrical remiges lacking barbules are attached along its forelimbs and elongate hindlimb feathers extend up to its toes, suggesting that hindlimb remiges evolved in ground-dwelling maniraptorans before being co-opted to an arboreal lifestyle or flight.

Sedimentation of Jurassic fan-delta wedges in the Xiahuayuan basin reflecting thrust-fault movements of the western Yanshan fold-and-thrust belt, China

NASA Astrophysics Data System (ADS)

Lin, Chengfa; Liu, Shaofeng; Zhuang, Qitian; Steel, Ronald J.

2018-06-01

Mesozoic thrusting within the Yanshan fold-and-thrust belt of North China resulted in a series of fault-bounded intramontane basins whose infill and evolution remain poorly understood. In particular, the bounding faults and adjacent sediment accumulations along the western segments of the belt are almost unstudied. A sedimentological and provenance analysis of the Lower Jurassic Xiahuayuan Formation and the Upper Jurassic Jiulongshan Formation have been mapped to show two distinctive clastic wedges: an early Jurassic wedge representing a mass-flow-dominated, Gilbert-type fan delta with a classic tripartite architecture, and an late Jurassic shoal-water fan delta without steeply inclined strata. The basinward migration of the fan-delta wedges, together with the analysis of their conglomerate clast compositions, paleocurrent data and detrital zircon U-Pb age spectra, strongly suggest that the northern-bounding Xuanhuan thrust fault controlled their growth during accumulation of the Jiulongshan Formation. Previous studies have suggested that the fan-delta wedge of the Xiahuayuan Formation was also syntectonic, related to movement on the Xuanhua thrust fault. Two stages of thrusting therefore exerted an influence on the formation and evolution of the Xiahuayuan basin during the early-late Jurassic.

Rural Navajo Students in Kayenta Unified School District's Special Education Programs: The Effects of Home Location and Language.

ERIC Educational Resources Information Center

Heimbecker, Connie; Bradley-Wilkinson, Evangeline; Nelson, Bernita; Smith, Jody; Whitehair, Marsha; Begay, Mary H.; Bradley, Brian; Gamble, Armanda; McCarty, Nellie; Medina, Catherine; Nelson, Jacob; Pettigrew, Bobbie; Sealander, Karen; Snyder, Maria; White, Sherri; Redsteer, Denise; Prater, Greg

In Kayenta Unified School District (KUSD) on the Navajo Reservation, 92 percent of students come from homes where Navajo is the primary language, but many students entering school are not fluent in either English or Navajo. A survey of 23 educators examined the effects of language and culture on the likelihood that a student would be placed in…

Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

PubMed Central

Butler, Richard J.; Galton, Peter M.; Porro, Laura B.; Chiappe, Luis M.; Henderson, Donald M.; Erickson, Gregory M.

2010-01-01

The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade. PMID:19846460

Middle to Upper Jurassic sedimentary sequences and marine biota of the early Indian Ocean (Southwest Madagascar): some biostratigraphic, palaeoecologic and palaeobiogeographic conclusions

NASA Astrophysics Data System (ADS)

Mette, Wolfgang

2004-03-01

As part of an intradisciplinary project which was concerned with the early rifting processes between Madagascar and East Africa, the Middle to Upper Jurassic sedimentary sequences of the Morondava Basin in Southwest Madagascar has been investigated with respect to biostratigraphy, sedimentary facies and palaeoecology. The transgressive sedimentary sections in the Bajocian and Callovian-Oxfordian yield rich macro- and microfossil assemblages which improved the biostratigraphic framework and gave some important information about the palaeoenvironments. Palaeogeographic distribution patterns of the Bajocian ostracod Paradoxorhyncha are suggestive of a migration along the southern shores of Gondwana between Madagascar, Australia and South America. The Callovian ostracods show strong affinities to the Indian faunas, indicating existence of a free migration route for shallow marine benthic organisms between Madagascar and India. Significant faunal differences between Madagascar and Tanzania suggest a physical or environmental migration barrier between Madagascar and East Africa during the Callovian to Kimmeridgian interval. The Upper Jurassic ostracods from the northern and eastern margin of Gondwana show a very high degree of endemism and they can be assigned to two faunal provinces in North Gondwana (Arabia, Near East, North Africa) and South Gondwana (India, Madagascar, East Africa).

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.

Reaching American Indian Special/Elementary Educators through a Partnership with a Navajo Nation School District.

ERIC Educational Resources Information Center

Heimbecker, Connie; Medina, Catherine; Peterson, Patricia; Redsteer, Denise; Prater, Greg

2002-01-01

This article describes the Reaching American Indian Special/Elementary Educators (RAISE) program, a community-based native teacher education program located on the Navajo reservation in Kayenta, Arizona. The preservice teacher preparation partnership program is designed for uncertified Navajo special and elementary education preservice students…

RadNet Air Data From Navajo Lake, NM

EPA Pesticide Factsheets

This page presents radiation air monitoring and air filter analysis data for Navajo Lake, NM from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

An enigmatic plant-eating theropod from the Late Jurassic period of Chile.

PubMed

Novas, Fernando E; Salgado, Leonardo; Suárez, Manuel; Agnolín, Federico L; Ezcurra, Martín D; Chimento, Nicolás R; de la Cruz, Rita; Isasi, Marcelo P; Vargas, Alexander O; Rubilar-Rogers, David

2015-06-18

Theropod dinosaurs were the dominant predators in most Mesozoic era terrestrial ecosystems. Early theropod evolution is currently interpreted as the diversification of various carnivorous and cursorial taxa, whereas the acquisition of herbivorism, together with the secondary loss of cursorial adaptations, occurred much later among advanced coelurosaurian theropods. A new, bizarre herbivorous basal tetanuran from the Upper Jurassic of Chile challenges this conception. The new dinosaur was discovered at Aysén, a fossil locality in the Upper Jurassic Toqui Formation of southern Chile (General Carrera Lake). The site yielded abundant and exquisitely preserved three-dimensional skeletons of small archosaurs. Several articulated individuals of Chilesaurus at different ontogenetic stages have been collected, as well as less abundant basal crocodyliforms, and fragmentary remains of sauropod dinosaurs (diplodocids and titanosaurians).

Swelling behaviour of Early Jurassic shales when exposed to water vapour

NASA Astrophysics Data System (ADS)

Houben, Maartje; Barnhoorn, Auke; Peach, Colin; Drury, Martyn

2017-04-01

The presence of water in mudrocks has a largely negative impact on production of gas, due to the fact that water causes swelling of the rock. Removing the water from the mudrock on the other hand could potentially shrink the rock and increase the matrix permeability. Investigation of the swelling/shrinkage behaviour of the rock during exposure to water vapour is of key importance in designing and optimizing unconventional production strategies. We have used outcrop samples of the Whitby Mudstone and the Posidonia shale [1], potential unconventional sources for gas in North-western Europe, to measure the swelling and shrinkage behaviour. Subsamples, 1 mm cubes, were prepared by the Glass Workshop at Utrecht University using a high precision digitally controlled diamond wafering saw cooled by air. The mm cubes were then exposed to atmospheres with different relative humidities either in an Environmental Scanning Electron Microscope (ESEM) or in a 3D dilatometer. So that the sample responses to exposure of water vapour could be measured. Parallel to the bedding we found a swelling strain between 0.5 and 1.5 %, perpendicular to the bedding though swelling strain varied between 1 and 3.5%. Volumetric swelling strain varied between 1 and 2% at a maximum relative humidity of 95%. Volumetric swelling strains measured in the Early Toarcian Shales are similar to the ones found in coal [2], where the results suggest that it might be possible to increase permeability in the reservoir by decreasing the in-situ water activity due to shrinkage of the matrix. [1] M.E. Houben, A. Barnhoorn, L. Wasch, J. Trabucho-Alexandre, C. J. Peach, M.R. Drury (2016). Microstructures of Early Jurassic (Toarcian) shales of Northern Europe, International Journal of Coal Geology, 165, 76-89. [2] Jinfeng Liu, Colin J. Peach, Christopher J. Spiers (2016). Anisotropic swelling behaviour of coal matrix cubes exposed to water vapour: Effects of relative humidity and sample size, International Journal of

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.

Disaster risk assessment case study: Recent drought on the Navajo Nation, USA

USGS Publications Warehouse

Hiza, Margaret; Kelley, Klara B.; Francis, Harris; Block, Debra

2011-01-01

The Navajo Nation is an ecologically sensitive semi-arid to arid section of the southern Colorado Plateau. In this remote part of the United States, located at the Four Corners (Arizona, New Mexico, Colorado, and Utah), traditional people live a subsistence lifestyle that is inextricably tied to, and dependent upon, landscape conditions and water supplies. Soft bedrock lithologies and sand dunes dominate the region, making it highly sensitive to fluctuations in precipitation intensity, percent vegetation cover, and local land use practices. However, this region has sparse and discontinuous meteorological monitoring records. As a complement to the scant long-term meteorological records and historical documentation, we conducted interviews with 50 Native American elders from the Navajo Nation and compiled their lifetime observations on the changes in water availability, weather, and sand or dust storms. We then used these observations to further refine our understanding of the historical trends and impacts of climate change and drought for the region. In addition to altered landscape conditions due to climatic change, drought, and varying land use practices over the last 130 years, the Navajo people have been affected by federal policies and harsh economic conditions which weaken their cultural fabric. We conclude that a long-term drying trend and decreasing snowpack, superimposed on regional drought cycles, will magnify drought impacts on the Navajo Nation and leave its people increasingly vulnerable.

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,…

Early Jurassic Volcanism in the South Lhasa Terrane, Southern Tibet: Record of Back-arc Extension in the Active Continental Margin

NASA Astrophysics Data System (ADS)

Wei, Y.; Zhao, Z.; Zhu, D. C.; Wang, Z.; Liu, D.; Mo, X.

2015-12-01

Indus-Yarlung Zangbo Suture Zone (IYZSZ) represents the Mesozoic remnants of the Neo-Tethyan Ocean lithosphere after its northward subduction beneath the Lhasa Terrane. The evolution of the Neo-Tethyan Ocean prior to India-Asia collision remains unclear. To explore this period of history, we investigate zircon U-Pb geochronology, geochemistry and Nd-Hf isotopes of the Early Jurassic bimodal-like volcanic sequence around Dagze area, south Tibet. The volcanic sequence comprises calc-alkaline basalts to rhyolites whereas intermediate components are volumetrically restricted. Zircons from a basaltic andesite yielded crystallization age of 178Ma whereas those from 5 silicic rocks were dated at 183-174Ma, which suggest that both the basaltic and the silicic rocks are coeval. The basaltic rocks are enriched in LREE and LILE, and depleted in HFSE, with Epsilon Nd(t) of 1.6-4.0 and zircon Epsilon Hf(t) of 0.7-11.8, which implies that they were derived from a heterogenetic mantle source metasomatized by subduction components. Trace element geochemistry shows that the basaltic rocks are compositionally transitional from normal mid-ocean ridge basalts (N-MORB) to island arc basalts (IAB, e.g. Zedong arc basalts of ~160-155Ma in the south margin of Lhasa Terrane), with the signature of immature back-arc basin basalts. The silicic rocks display similar Nd-Hf isotopic features of the Gangdese batholith with Epsilon Nd(t) of 0.9-3.4 and zircon Epsilon Hf(t) of 2.4-17.7, indicating that they were possibly generated by anatexis of basaltic juvenile lower crust, instead of derived from the basaltic magma. These results support an Early to Middle Jurassic (183-155Ma) model that the back-arc extension tectonic setting were existing in the active continental margin in the south Lhasa Terrane.

Parent Support Services on the Navajo Reservation.

ERIC Educational Resources Information Center

Jones, Doris; Miller, Susan; Medina, Catherine

A study examined the degree to which families with disabled children in remote areas of the Navajo Reservation were aware of and used family support services. Twenty-five undergraduate students enrolled in special education teacher training courses designed, implemented, and assisted in data analysis. Interviews and surveys were completed by 89…

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"…

Geological and technological characterization of the Late Jurassic-Early Cretaceous clay deposits (Jebel Ammar, northeastern Tunisia) for ceramic industry

NASA Astrophysics Data System (ADS)

Ben M'barek-Jemaï, Moufida; Sdiri, Ali; Ben Salah, Imed; Ben Aissa, Lassaad; Bouaziz, Samir; Duplay, Joelle

2017-05-01

Late Jurassic-Lower Cretaceous clays of the Jebel Ammar study site were used as raw materials for potential applications in ceramic industry. Physico-chemical characterization of the collected samples was performed using atomic absorption spectroscopy, X-ray diffraction, thermogravimetry and dilatometry (Bugot's curve). Geotechnical study was also undertaken by the assessment of plasticity and liquidity limits. It was found that high concentrations of silica, alumina with SiO2/Al2O3 ratio characterized the studied clays; its high amounts of CaO and Fe2O3 in the Late Jurassic clays indicated their calcareous nature. In addition, technological tests indicated moderate to low plasticity values for the Late Jurassic and Lower Cretaceous clays, respectively. Clay fraction (<2 μm) reached 50% of the natural clay in some cases. Mineralogical analysis showed that Jurassic clays were dominated by smectite, illite and kaolinite, as clay mineral species; calcite was the main associated mineral. Lower Cretaceous clays were mainly composed of abundant illite accompanied by well-crystallized smectite and kaolinite. Kaolinite gradually increased upwards, reaching 70% of the total clay fraction (i.e. <2 μm). Quartz, calcite and feldspar were the main non-clay minerals. Based on these analyses, the clays meet technological requirements that would allow their use in the ceramic industry and for the manufacturing of ceramic tiles.

Old Torreon Navajo Day School, Cuba, NM: NN0030341

EPA Pesticide Factsheets

NPDES Permit and Fact Sheet explaining EPA's action under the Clean Water Act to issue NPDES Permit No. NN0030341 to Bureau of Indian Affairs Old Torreon Navajo Day School Wastewater Treatment Lagoon.

Latest Jurassic ammonoid provinces: Paleoecological implications using a general circulation model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, C.A.; Moore, G.T.; Hayashida, D.N.

1992-01-01

The Lake Permian-early Mesozoic megacontinent Pangea was progressively fragmented by two rift systems that propagated westward out of the Tethys Sea and a third more persistent rift system that connected the Boreal and Tethys seas. By the late Tithonian, these major rift systems produced interconnected oceanic seaways that divided Pangea into four continental segments: North America, Eur-Asia, and northern and southern Gondwana. Increased rates of sea-floor spreading during the Jurassic reduced the volumetric capacity of ocean basins and produced a sea level rise through the period that culminated in the Lake Jurassic. The extensive marine shelf margins and epeiric seasmore » hosted a widely distributed and diverse ammonoid fauna. By the early Tithonian, faunal communication existed between the northwestern Tethys Sea and the eastern Panthalassa Ocean through the proto-Gulf of Mexico. By the late Tithonian, faunal similarities indicate the opening of the proto-Indian Ocean so that northern and southern Gondwana had become separate continents. A region of the equatorial Tethys that includes most of the present Arabian Peninsular contains neuritic platform facies but lacks ammonoids. In high northern latitudes, cool to cold water faunas formed a Boreal Realm which extended westward across northern North America, Europe, and Siberia during middle and late Tithonian. Late Kimmeridgian and Tithonian ammonoid distributions when compared with Late Jurassic paleoclimate simulations show likely causal relationships with sea surface water temperatures and upwelling, and possibly shed light on the temperature limitations of ammonoids. Results from modeled seasonal sea surface temperature, sea ice distribution, precipitation-evaporation, and wind-driven upwelling permit the evaluation and quantification of paleoenvironmental factors favorable as well as pernicious for ammonoid distribution.« less

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.

78 FR 17743 - Navajo Nation Disaster #AZ-00026

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... SMALL BUSINESS ADMINISTRATION [Disaster Declaration 13515 and 13516] Navajo Nation Disaster AZ-00026 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409 3rd...

Mayer Kangri metamorphic complexes in Central Qiangtang (Tibet, western China): implications for the Triassic-early Jurassic tectonics associated with the Paleo-Tethys Ocean

NASA Astrophysics Data System (ADS)

Wang, Yixuan; Liang, Xiao; Wang, Genhou; Yuan, Guoli; Bons, Paul D.

2018-03-01

The Mesozoic orogeny in Central Qiangtang Metamorphic Belt, northern Tibet, provides important insights into the geological evolution of the Paleo-Tethys Ocean. However, the Triassic-early Jurassic tectonics, particularly those associated with the continental collisionstage, remains poorly constrained. Here we present results from geological mapping, structural analysis, P-T data, and Ar-Ar geochronology of the Mayer Kangri metamorphic complex. Our data reveal an E-W-trending, 2 km wide dome-like structure associated with four successive tectonic events during the Middle Triassic and Early Jurassic. Field observations indicate that amphibolite and phengite schist complexes in this complex are separated from the overlying lower greenschist mélange by normal faulting with an evident dextral shearing component. Open antiform-like S2 foliation of the footwall phengite schist truncates the approximately north-dipping structures of the overlying mélange. Microtextures and mineral chemistry of amphibole reveal three stages of growth: Geothermobarometric estimates yield temperatures and pressures of 524 °C and 0.88 GPa for pargasite cores, 386 °C and 0.34 GPa for actinolite mantles, and 404 °C and 0.76 GPa for winchite rims. Peak blueschist metamorphism in the phengite schist occurred at 0.7-1.1 GPa and 400 °C. Our Ar-Ar dating of amphibole reveals rim-ward decreasing in age bands, including 242.4-241.2 Ma, ≥202.6-196.8, and 192.9-189.8 Ma. The results provide evidence for four distinct phases of Mesozoic tectonic evolution in Central Qiangtang: (1) northward oceanic subduction beneath North Qiangtang ( 244-220 Ma); (2) syn-collisional slab-break off (223-202 Ma); (3) early collisional extension driven by buoyant extrusion flow from depth ( 202.6-197 Ma); and (4) post-collision contraction and reburial (195.6-188.7 Ma).

Basin evolution during the transition from continental rifting to subduction: Evidence from the lithofacies and modal petrology of the Jurassic Latady Group, Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Willan, Robert C. R.; Hunter, Morag A.

2005-12-01

The Jurassic Latady Basin (southern Antarctic Peninsula) developed in a broad rift zone associated with the early stages of Gondwana extension. Early Jurassic sedimentation (˜185 Ma) occurred in small, isolated terrestrial to lacustrine rift basins in the present-day northwest and west and became shallow marine by the early Middle Jurassic. Quantitative modal analysis reveals a high proportion of mature, quartzose sandstone derived from cratonic and quartzose recycled-orogen provenances, most likely in the direction of the Ellsworth-Whitmore Mountains in the Gondwana interior. Sandstones with a more volcanolithic provenance probably represent an influx of sands from a Permian volcanic source in West Antarctica. The Early Jurassic Latady sequence contains abundant volcanic quartz and rhyodacite grains, locally derived from the nearby ignimbrites of the rift-related Mount Poster Formation (˜185 Ma). Between the Middle and Late Jurassic (?160-150 Ma), there was a dramatic change throughout the Latady Basin to higher-energy conditions with marked lateral facies variations. Sandstones contain abundant fresh volcanic detritus and plot in the transitional arc field. Their source was a nearby, active continental margin arc, but there is no outcrop of arc material on the Antarctic Peninsula from this time. A possible source area is preserved on the Thurston Island block to the southwest. However, some fluvial systems still had access to areas of uplifted metamorphic/plutonic basement and quartzose, cratonic sources. Evidence of mixing of fluvial systems from different provenances and the lack of mixing of other fluvial systems suggest a complex topography of variably uplifted fault blocks with fluvial systems constrained in narrow valleys. The change from continental rift- to arc-related sources illustrates the shift from plume- (continental provenances) to continental margin arc-dominated tectonics. Thermal relaxation in the Late Jurassic led to the final phase of

A Jurassic wood providing insights into the earliest step in Ginkgo wood evolution.

PubMed

Jiang, Zikun; Wang, Yongdong; Philippe, Marc; Zhang, Wu; Tian, Ning; Zheng, Shaolin

2016-12-16

The fossil record of Ginkgo leaf and reproductive organs has been well dated to the Mid-Jurassic (170 Myr). However, the fossil wood record that can safely be assigned to Ginkgoales has not yet been reported from strata predating the late Early Cretaceous (ca. 100 Myr). Here, we report a new fossil wood from the Mid-Late Jurassic transition deposit (153-165 Myr) of northeastern China. The new fossil wood specimen displays several Ginkgo features, including inflated axial parenchyma and intrusive tracheid tips. Because it is only slightly younger than the oldest recorded Ginkgo reproductive organs (the Yima Formation, 170 Myr), this fossil wood very probably represents the oldest bona fide fossil Ginkgo wood and the missing ancestral form of Ginkgo wood evolution.

A Jurassic wood providing insights into the earliest step in Ginkgo wood evolution

NASA Astrophysics Data System (ADS)

Jiang, Zikun; Wang, Yongdong; Philippe, Marc; Zhang, Wu; Tian, Ning; Zheng, Shaolin

2016-12-01

The fossil record of Ginkgo leaf and reproductive organs has been well dated to the Mid-Jurassic (170 Myr). However, the fossil wood record that can safely be assigned to Ginkgoales has not yet been reported from strata predating the late Early Cretaceous (ca. 100 Myr). Here, we report a new fossil wood from the Mid-Late Jurassic transition deposit (153-165 Myr) of northeastern China. The new fossil wood specimen displays several Ginkgo features, including inflated axial parenchyma and intrusive tracheid tips. Because it is only slightly younger than the oldest recorded Ginkgo reproductive organs (the Yima Formation, 170 Myr), this fossil wood very probably represents the oldest bona fide fossil Ginkgo wood and the missing ancestral form of Ginkgo wood evolution.

Sedimentological, climatic and environmental changes during the Early Jurassic (Hettangian-Pliensbachian) on the northern Tethyan margin (Switzerland)

NASA Astrophysics Data System (ADS)

Schöllhorn, Iris; Foellmi, Karl; adatte, Thierry

2016-04-01

The Early Jurassic interval witnessed different phases of paleoenvironmental change, starting with the end-Triassic mass extinction event, c. 201.4 Ma ago, which was marked by terrestrial ecosystem turnover, up to 50% loss in marine biodiversity and large turnovers in global geochemical cycles linked to the onset of Central Atlantic Magmatic Province volcanism (Raup et Sepkosky, 1982 ; Hesselbo et al., 2002 ; Deenen et al., 2010). This time interval saw equally a phase of major climate change near the Pliensbachian-Toarcian boundary, which was followed by the Early Toarcian oceanic anoxic episode (e.g., Suan et al., 2010). Previous studies mainly focused on these major and short-lived events, while the remaining intervals of the Early Jurassic received significantly less attention. Therefore, in this study, we examine the sedimentological, geochemical and environmental changes between these events on the northern Tethyan margin (Swiss Jura). With this purpose, a wide array of geochemical analyses (carbon isotope, Rock-Eval, phosphorus content, mineralogy, trace and major element content and clay analyses) and sedimentary observations has been performed on four sections and cores (Frick, Riniken, Pfaffnau and Kreuzlingen). We observed two depositional systems: (1) the Schambelen Member (lower Hettangian) and the Frick Mb. (middle Upper Sinemurian), which are characterised by organic-rich shales intercalated by tempestites; and (2) the Beggingen Member (Upper Hettangian to Lower Sinemurian) and the Grünscholz, Breitenmatt and Rietheim Members (upper Upper Sinemurian to Pliensbachian), which are composed of carbonates marked by the presence of hiati, condensed beds, phosphate- and fossil-rich strata, and erosional features, which testify to a dynamic environment characterised by overall low sediment-accumulation rates. The clay fraction, composed mainly of kaolinite, chlorite and illite, was controlled by various parameters. The rise of kaolinite in the Late

Abandoned Uranium Mine (AUM) Points, Navajo Nation, 2016, US EPA Region 9

EPA Pesticide Factsheets

This GIS dataset contains point features of all Abandoned Uranium Mines (AUMs) on or within one mile of the Navajo Nation. Points are centroids developed from the Navajo Nation production mines polygon dataset that comprise of productive or unproductive Abandoned Uranium Mines. Attributes include mine names, aliases, links to AUM reports, indicators whether an AUM was mined above or below ground, indicators whether an AUM was mined above or below the local water table, and the region in which an AUM is located. This dataset contains 608 features.

Rise and demise of the Bahama-Grand Banks gigaplatform, northern margin of the Jurassic proto-Atlantic seaway

USGS Publications Warehouse

Poag, C. Wylie

1991-01-01

An extinct, > 5000-km-long Jurassic carbonate platform and barrier reef system lies buried beneath the Atlantic continental shelf and slope of the United States. A revised stratigraphic framework, a series of regional isopach maps, and paleogeographic reconstructions are used to illustrate the 42-m.y. history of this Bahama-Grand Banks gigaplatform from its inception in Aalenian(?) (early Middle Jurassic) time to its demise and burial in Berriasian-Valanginian time (early Early Cretaceous). Aggradation-progradation rates for the gigaplatform are comparable to those of the familiar Capitan shelf margin (Permian) and are closely correlated with volumetric rates of siliciclastic sediment accumulation and depocenter migration. Siliciclastic encroachment behind the carbonate tracts appears to have been an important impetus for shelf-edge progradation. During the Early Cretaceous, sea-level changes combined with eutrophication (due to landward soil development and seaward upwelling) and the presence of cooler upwelled waters along the outer shelf appear to have decimated the carbonate producers from the Carolina Trough to the Grand Banks. This allowed advancing siliciclastic deltas to overrun the shelf edge despite a notable reduction in siliciclastic accumulation rates. However, upwelling did not extend southward to the Blake-Bahama megabank, so platform carbonate production proceeded there well into the Cretaceous. Subsequent stepwise carbonate abatement characterized the Blake Plateau Basin, whereas the Bahamas have maintained production to the present. The demise of carbonate production on the northern segments of the gigaplatform helped to escalate deep-water carbonate deposition in the Early Cretaceous, but the sudden augmentation of deep-water carbonate reservoirs in the Late Jurassic was triggered by other agents, such as global expansion of nannoplankton communities. ?? 1991.

Petrosal anatomy and inner ear structures of the Late Jurassic Henkelotherium (Mammalia, Cladotheria, Dryolestoidea): insight into the early evolution of the ear region in cladotherian mammals

PubMed Central

Ruf, Irina; Luo, Zhe-Xi; Wible, John R; Martin, Thomas

2009-01-01

The petrosal anatomy and inner ear structure of Jurassic cladotherian mammals represent the ancestral morphological conditions (groundplan) from which modern therian mammals (marsupials and placentals) have evolved. We present the reconstruction of the petrosal and inner ear features of the Late Jurassic dryolestoid mammal Henkelotherium guimarotae from high-resolution computed tomography and three-dimensional imaging analysis. This study of Henkelotherium revealed a combination of derived and primitive features, including: cladotherian apomorphies, such as the promontorial sulcus for the internal carotid artery and reduced lateral trough; trechnotherian characters, such as an enclosed cochlear canaliculus for the perilymphatic duct, post-promontorial tympanic sinus and caudal tympanic process; in addition to plesiomorphic mammalian features, such as the cavum supracochleare and prootic canal. The inner ear of Henkelotherium shows a division between the utricle and saccule, a cochlear canal coiled through at least 270°, a distinctive primary bony lamina for the basilar membrane, and a secondary bony lamina. The development of the primary and secondary bony laminae in the cochlear canal is suggested here to be correlated with the concurrent coiling of the bony canal and membranous duct of the inner ear cochlea, apomorphies of the more inclusive cladotherian clade that also represent the ancestral morphotype of modern therian mammals. Because these features are crucial for high-frequency hearing in extant therian mammals, their early appearance in Late Jurassic cladotherians suggests a more ancient origination for high-frequency hearing in mammalian history than previously thought. PMID:19438763

75 FR 71138 - Land Acquisitions; Navajo Nation, Arizona

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

... of land into trust for the Navajo Nation of Arizona on November 10, 2010. FOR FURTHER INFORMATION... Indians before transfer of title to the property occurs. On November 10, 2010, the Assistant Secretary... 21 North, Range 11 East, Gila and Salt River Meridian, Coconino County, Arizona, described as follows...

Risk Factors for Suicide Attempts among Navajo Adolescents.

ERIC Educational Resources Information Center

Grossman, David C.; And Others

1991-01-01

Examines risk factors for adolescent suicide among Navajos by comparing survey responses of students having attempted suicide with those of other students. A history of mental health problems, alienation from family and community, and having a friend commit suicide put students at a higher risk for suicide. (CJS)

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…

A preliminary population study of alcove bog orchid (Platanthera zothecina) at Navajo National Monument, Arizona

Treesearch

Laura E. Hudson

2001-01-01

This study on Platanthera zothecina (alcove bog orchid) was initiated by the National Park Service after a recent threatened and endangered species survey at Navajo National Monument. It is listed as Category 2 (species of special concern) by the U.S. Fish and Wildlife Service, and Category 3 (likely to become endangered) by the Navajo Nation. Because P. zothecina is a...

The prevalence and incidence of end-stage renal disease in Native American adults on the Navajo reservation.

PubMed

Hochman, M E; Watt, J P; Reid, R; O'Brien, K L

2007-05-01

Whereas members of the Navajo Nation are at high risk for diabetes mellitus, there are no recent published estimates of the burden of end-stage renal disease (ESRD), an important sequela of diabetes, on the Navajo Nation, a 16 million acre area in Arizona, New Mexico, and Utah with more than 200 000 tribal members. We used data from the US Renal Data System to estimate the prevalence and incidence of ESRD among Native American adults (>/=18 years) living on the Navajo Nation. For comparison, we estimated the prevalence and incidence of ESRD among all adults in the US, all Native American adults in the US, and Native American adults living in Arizona, New Mexico, Utah, and Colorado excluding those living on the Navajo Nation. The age-adjusted prevalence of ESRD in the Native American adults on the Navajo Nation was 0.63%, which was higher than in the US adults (0.19%, P<0.0001) and among the Native American adults in the US (0.36%, P<0.0001), but lower than among the other Native American adults in the Southwest (0.89%, P<0.0001). The age-adjusted incidence of ESRD in the Native American adults on the Navajo Nation was 0.11%, which was also higher than in the US adults (0.045%, P<0.0001) and among the Native American adults in the US (0.073%, P<0.0009), but lower than among the other Native American adults in the Southwest (0.17%, P<0.0003). The reasons behind these disparities merit further study.

25 CFR 161.713 - How will BIA determine the amount of damages to Navajo Partitioned Lands?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false How will BIA determine the amount of damages to Navajo Partitioned Lands? 161.713 Section 161.713 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Penalties, Damages, and Costs § 161.713...

Yéego Gardening! A Community Garden Intervention to Promote Health on the Navajo Nation.

PubMed

Ornelas, India J; Deschenie, Desiree; Jim, Jesse; Bishop, Sonia; Lombard, Kevin; Beresford, Shirley A

2017-01-01

Yéego Gardening! is a community garden intervention to increase gardening behavior, increase access to low-cost fruit and vegetables, and ultimately increase consumption in Navajo communities. To design a theory-based, culturally relevant intervention with three components: a community garden, monthly workshops on gardening and healthy eating, and community outreach. Gardens were constructed and maintained in collaboration with community-based organizations in two Navajo communities. Monthly workshops were held throughout the growing season and incorporated aspects of Navajo culture and opportunities to build confidence and skills in gardening and healthy eating behaviors. In addition, program staff attended community events to promote gardening and healthy eating. Community input was essential throughout the planning and implementation of the intervention. If effective, community gardens may be a way to increase fruit and vegetable availability and intake, and ultimately reduce risk of obesity and diabetes.

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…

A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids.

PubMed

Pol, Diego; Rauhut, Oliver W M; Becerra, Marcos

2011-05-01

Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Cañadón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60-75 cm, Manidens furthermore confirms the small size of basal heterodontosaurids.

A Middle Jurassic heterodontosaurid dinosaur from Patagonia and the evolution of heterodontosaurids

NASA Astrophysics Data System (ADS)

Pol, Diego; Rauhut, Oliver W. M.; Becerra, Marcos

2011-05-01

Heterodontosauridae is a morphologically divergent group of dinosaurs that has recently been interpreted as one of the most basal clades of Ornithischia. Heterodontosaurid remains were previously known from the Early Jurassic of southern Africa, but recent discoveries and studies have significantly increased the geographical and temporal range for this clade. Here, we report a new ornithischian dinosaur from the Middle Jurassic Cañadón Asfalto Formation in central Patagonia, Argentina. This new taxon, Manidens condorensis gen. et sp. nov., includes well-preserved craniomandibular and postcranial remains and represents the only diagnostic ornithischian specimen yet discovered in the Jurassic of South America so far. Derived features of its anatomy indicate that Manidens belongs to Heterodontosauridae, as the sister taxon of Heterodontosaurus and other South African heterodontosaurids. The presence of posterior dentary teeth with high crowns but lacking extensive wear facets in Manidens suggests that this form represents an intermediate stage in the development of the remarkable adaptations to herbivory described for Heterodontosaurus. The dentition of Manidens condorensis also has autapomorphies, such as asymmetrically arranged denticles in posterior teeth and a mesially projected denticle in the posteriormost teeth. At an estimated total length of 60-75 cm, Manidens furthermore confirms the small size of basal heterodontosaurids.

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. Copyright © 2014 Elsevier Inc. All rights reserved.

Dinosaur evolution. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales.

PubMed

Godefroit, Pascal; Sinitsa, Sofia M; Dhouailly, Danielle; Bolotsky, Yuri L; Sizov, Alexander V; McNamara, Maria E; Benton, Michael J; Spagna, Paul

2014-07-25

Middle Jurassic to Early Cretaceous deposits from northeastern China have yielded varied theropod dinosaurs bearing feathers. Filamentous integumentary structures have also been described in ornithischian dinosaurs, but whether these filaments can be regarded as part of the evolutionary lineage toward feathers remains controversial. Here we describe a new basal neornithischian dinosaur from the Jurassic of Siberia with small scales around the distal hindlimb, larger imbricated scales around the tail, monofilaments around the head and the thorax, and more complex featherlike structures around the humerus, the femur, and the tibia. The discovery of these branched integumentary structures outside theropods suggests that featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade; feathers may thus have been present in the earliest dinosaurs. Copyright © 2014, American Association for the Advancement of Science.

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.

The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution.

PubMed

Caldwell, Michael W; Nydam, Randall L; Palci, Alessandro; Apesteguía, Sebastián

2015-01-27

The previous oldest known fossil snakes date from ~100 million year old sediments (Upper Cretaceous) and are both morphologically and phylogenetically diverse, indicating that snakes underwent a much earlier origin and adaptive radiation. We report here on snake fossils that extend the record backwards in time by an additional ~70 million years (Middle Jurassic-Lower Cretaceous). These ancient snakes share features with fossil and modern snakes (for example, recurved teeth with labial and lingual carinae, long toothed suborbital ramus of maxillae) and with lizards (for example, pronounced subdental shelf/gutter). The paleobiogeography of these early snakes is diverse and complex, suggesting that snakes had undergone habitat differentiation and geographic radiation by the mid-Jurassic. Phylogenetic analysis of squamates recovers these early snakes in a basal polytomy with other fossil and modern snakes, where Najash rionegrina is sister to this clade. Ingroup analysis finds them in a basal position to all other snakes including Najash.

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…

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...

Preventing Caries in Preschoolers: Successful Initiation of an Innovative Community-Based Clinical Trial in Navajo Nation Head Start

PubMed Central

Quissell, David O.; Bryant, Lucinda L.; Braun, Patricia A.; Cudeii, Diana; Johs, Nikolas; Smith, Vongphone L.; George, Carmen; Henderson, William G.; Albino, Judith

2014-01-01

Navajo Nation children have the greatest prevalence of early childhood caries in the United States. This protocol describes an innovative combination of community-based participatory research and clinical trial methods to rigorously test a lay native Community Oral Health Specialists-delivered oral health intervention, with the goal of reducing the progression of disease and improving family knowledge and behaviors. Methods/Design This cluster-randomized trial designed by researchers at the Center for Native Oral Health Research at the University of Colorado in conjunction with members of the Navajo Nation community compares outcomes between the manualized 2-year oral health fluoride varnish-oral health promotion intervention and usual care in the community (child-caregiver dyads from 26 Head Start classrooms in each study arm; total of 1016 dyads). Outcome assessment includes annual dental screening and an annual caregiver survey of knowledge, attitudes and behaviors; collection of cost data will support cost-benefit analyses. Discussion The study protocol meets all standards required of randomized clinical trials. Aligned with principles of community-based participatory research, extended interaction between members of the Navajo community and researchers preceded study initiation, and collaboration between project staff and a wide variety of community members informed the study design and implementation. We believe the benefits of adding CBPR methods to those of randomized clinical studies outweigh the barriers and constraints, especially in studies of health disparities and in challenging settings. When done well, this innovative mix of methods will increase the likelihood of valid results that communities can use. PMID:24469238

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.

Wildfire Activity Across the Triassic-Jurassic Boundary in the Polish Basin: Evidence from New Fossil Charcoal & Carbon-isotope Data

NASA Astrophysics Data System (ADS)

Pointer, R.; Belcher, C.; Hesselbo, S. P.; Hodbod, M.; Pieńkowski, G.

2017-12-01

New fossil charcoal abundance and carbon-isotope data from two sedimentary cores provide new evidence of extreme environmental conditions in the Polish Basin during the Latest Triassic to Earliest Jurassic. Sedimentary cores from the Polish Basin provide an excellent record of terrestrial environmental conditions across the Triassic-Jurassic Boundary, a time of climatic extremes. Previous work has shown that the marine realm was affected by a large perturbation to the carbon cycle across the Triassic-Jurassic Boundary (manifested by large negative and positive carbon-isotope excursions) and limited records of charcoal abundance and organic geochemistry have indicated important changes in fire regime in the coeval ecosystems. Here we present two new carbon-isotope records generated from fossil plant matter across the Triassic-Jurassic boundary, and present new charcoal records. The charcoal abundance data confirm that there was variation in wildfire activity during the Late Triassic-Early Jurassic in the Polish Basin. Peaks in the number of fossil charcoal fragments present occur in both sedimentary cores, and increases in fossil charcoal abundance are linked to wildfires, signalling a short-lived rise in wildfire activity. Fossil charcoal abundance does not appear to be fully controlled by total organic matter content, depositional environment or bioturbation. We argue that increased wildfire activity is likely caused by an increase in ignition of plant material as a result of an elevated number of lightning strikes. Global warming (caused by a massive input of carbon into the atmosphere, as indicated by carbon-isotope data) can increase storm activity, leading to increased numbers of lightning strikes. Previous Triassic-Jurassic Boundary wildfire studies have found fossil charcoal abundance peaks at other northern hemisphere sites (Denmark & Greenland), and concluded that they represent increases in wildfire activity in the earliest Jurassic. Our new charcoal and

Water-quality data for Navajo National Monument, northeastern Arizona--2001-02

USGS Publications Warehouse

Thomas, Blakemore E.

2003-01-01

Water-quality data are provided for six sites in Navajo National Monument in northeastern Arizona. These data describe the current water quality and provide baseline water-quality information for monitoring future trends. Water samples were collected from six sites near three ancient Indian ruins during September 2001 to August 2002. Two springs and one well near Betatakin Ruin, one spring is near Keet Seel Ruin, and one spring and one stream are near Inspection House Ruin. Water from all the sites is from the N aquifer, a regional sandstone aquifer that is the source of drinking water for most members of the Navajo Nation and Hopi Tribe in northeastern Arizona. Concentrations of dissolved solids, major ions, trace elements, and uranium were low at the six sites. Dissolved-solids concentration ranged from 94 to 221 milligrams per liter. Concentrations of dissolved nitrate (as nitrogen) were generally low (less than 0.05 to 0.92 milligrams per liter) and were within the range of concentrations at other N-aquifer sites within 20 miles of the study area. Water samples from Inscription House Spring, Navajo Creek Tributary (near Inscription House Ruin), and Keet Seel Ruin Spring contained indicators of human or animal wastes--fecal coliform and Escherichia coli bacteria.

Paleomagnetism of Jurassic-Cretaceous basalts from the Franz Josef Land Archipelago: tectonic implications

NASA Astrophysics Data System (ADS)

Abashev, Victor; Mikhaltsov, Nikolay; Vernikovsky, Valery

2015-04-01

New paleomagnetic data were obtained from a total of 158 oriented samples collected from the Jurassic magmatic complexes exposed on the Franz Joseph Land Archipelago (FJL). The field work was conducted during 2011 field season. Present study was focused on the tholeiitic basaltic lava flows that crop out on the Hooker Island. The samples were subjected to a detailed step-wise thermal demagnetization in temperatures up to 600 deg C or alternating field demagnetization with maximum filed up to 140 mT. Natural remanent magnetization (NRM) was measured with a 2G cryogenic magnetometer or a JR-6A spin-magnetometer housed in a magnetically shielded room at the Institute of Petroleum Geology and Geophysics, Siberian Branch of Russian Academy of Sciences. The main NRM carriers in the FJL samples are titanomagnetites with varying Ti-content. Magnetic remanence was unblocked in temperatures of 350-400 deg C. Some samples are characterized by unblocking temperatures of 560 deg C. The new paleomagnetic data were combined with those previously obtained from the early Cretaceous volcanics exposed on the FJL. A new mean paleomagnetic direction for the Jurassic rocks was calculated as D=78.3 deg, I=74.7 deg, a95=3.1 deg, k=194.3, N=13. A corresponding paleomagnetic pole is now located at Plat=62.1 deg; Plon=136.5 deg, A95=5.5 deg, K=63.6. New results suggest that the JFL occupied a significantly different position from that of the present day. However, in early Cretaceous the JFL was already located close to its present day position. We propose a rifting event between the North Barentz terrane (FJL and possibly Svalbard) and the counterpart of European tectonic domain. The rifting occurred during Early-Middle Jurassic. This event was accompanied by a significant shift of the FJL to the north-east for approximately 500 km. New results are in good agreement with a hypothesis that the FJL was passing over the Icelandic-Siberian hot spot during the Jurassic-Cretaceous time

Jurassic, slow-spreading ridge in the southeast Gulf of Mexico and its along-strike morpho-volcanic expression explained by a two-phase opening model

NASA Astrophysics Data System (ADS)

Lin, P.; Mann, P.

2016-12-01

Previous workers have used extensive grids of 2D seismic reflection data to describe the width, structural character, and adjacent oceanic crust of the late Jurassic, slow-spreading ridge in the southeast Gulf of Mexico (SEGOM). Characteristics of the now-buried SEGOM slow spreading ridge include: 1) wide, axial valley segments ranging from 5-20 km; 2) alternating, deep, axial valley segments up to 2 km in depth; 3) normal faults dipping towards the axial valleys; and 4) isolated seamounts within the axial valleys projecting 1 km above regional oceanic basement depth and reflecting along-strike variations in the ridge's magmatic supply. We have used additional seismic reflection, gravity, and magnetic data to map the ridge and its environs to its southern termination, a 2.6-km-high seamount - informally named here Buffler seamount. The southernmost, 427-km long section of the SEGOM ridge from Buffler seamount northwest to the southwestern limit of the DeSoto Canyon arch can be divided into four alternating ridge segments with two distinctive morphologies: 1) wide and deep axial valleys lying below regional oceanic basement depth and characterized by gravity high and magnetic lows; and 2) elevated, linear areas of clustered, seamounts characterized by gravity low and magnetic highs. The continental margins of both Yucatan and Florida exhibit a prominent N60E magnetic fabric created by Phase 1, NW-SE Triassic-early Jurassic continental rifting of the GOM that was subsequently offset at right angles by Phase 2, NE-SW late Jurassic stretching and oceanic spreading. Removal of the V-shaped area of oceanic crust of the SEGOM shows that the wide, axial valleys of the late Jurassic spreading ridge coincide with rifted areas of thicker crust on the "arches" or horst blocks of Triassic-early Jurassic, Phase 1 rifting (Sarasota, Middle Ground) while the elevated areas of elevated and clustered seamounts coincide with thinner crust of the intervening rifts (Apalachicola, Tampa

Early Jurassic mafic dykes from the Aigao uranium ore deposit in South China: Geochronology, petrogenesis and relationship with uranium mineralization

NASA Astrophysics Data System (ADS)

Zhang, Di; Zhao, Kui-Dong; Chen, Wei; Jiang, Shao-Yong

2018-05-01

Mafic dykes are abundant and widely distributed in many granite-hosted uranium ore deposits in South China. However, their geochronology, petrogenesis and relationship with uranium mineralization were poorly constrained. In this study, apatite U-Pb dating, whole-rock major and trace element and Sr-Nd-Pb isotope analysis were conducted for the dolerite dykes from the Aigao uranium ore deposit. Apatite U-Pb isotopic data indicate that the mafic dykes were emplaced at Early Jurassic (189 ± 4 Ma), which provides new evidence for the rarely identified Early Jurassic magmatism in South China. Pyroxene from the dykes is mainly augite, and plagioclase belongs to albite. The dolerite samples have relatively low SiO2 contents (45.33-46.79 wt%), relatively high total alkali contents (K2O + Na2O = 4.11-4.58 wt%) and Al2O3 contents (13.39-13.80 wt%), and medium MgO contents (4.29-5.16 wt%). They are enriched in Nb, Ta, Ti, rare earth elements and depleted in Rb, K, Sr, Th, showing the typical OIB-like geochemical affinity. All the dolerite samples show homogeneous Sr-Nd-Pb isotopic compositions, with (87Sr/86Sr)i varying from 0.706049 to 0.707137, εNd(t) from +4.6 to +5.2, 206Pb/204Pb from 19.032 to 19.126 and 207Pb/204Pb from 15.641 to 15.653. The mafic dykes in the Aigao deposit should be derived from the partial melting of the asthenospheric mantle and formed in a within-plate extensional environment. The emplacement age of the mafic dykes is older than the uranium mineralization age. Therefore, CO2 in ore-forming fluids couldn't originate from the basaltic magma as suggested by previous studies. The dolerite dykes might only provide a favorable reducing environment to promote the precipitation of uraninite from oxidize hydrothermal fluids.

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…

Mantle source heterogeneity of the Early Jurassic basalt of eastern North America

NASA Astrophysics Data System (ADS)

Gregory Shellnutt, J.; Dostal, Jaroslav; Yeh, Meng-Wan

2018-04-01

One of the defining characteristics of the basaltic rocks from the Early Jurassic Eastern North America (ENA) sub-province of the Central Atlantic Magmatic Province (CAMP) is the systematic compositional variation from South to North. Moreover, the tectono-thermal regime of the CAMP is debated as it demonstrates geological and structural characteristics (size, radial dyke pattern) that are commonly associated with mantle plume-derived mafic continental large igneous provinces but is considered to be unrelated to a plume. Mantle potential temperature ( T P) estimates of the northern-most CAMP flood basalts (North Mountain basalt, Fundy Basin) indicate that they were likely produced under a thermal regime ( T P ≈ 1450 °C) that is closer to ambient mantle ( T P ≈ 1400 °C) conditions and are indistinguishable from other regions of the ENA sub-province ( T Psouth = 1320-1490 °C, T Pnorth = 1390-1480 °C). The regional mantle potential temperatures are consistent along the 3000-km-long ENA sub-province suggesting that the CAMP was unlikely to be generated by a mantle plume. Furthermore, the mantle potential temperature calculation using the rocks from the Northern Appalachians favors an Fe-rich mantle (FeOt = 8.6 wt %) source, whereas the rocks from the South Appalachians favor a less Fe-rich (FeOt = 8.3 wt %) source. The results indicate that the spatial-compositional variation of the ENA basaltic rocks is likely related to differing amounts of melting of mantle sources that reflect the uniqueness of their regional accreted terranes (Carolinia and West Avalonia) and their post-accretion, pre-rift structural histories.

Coupling Aeolian Stratigraphic Architecture to Paleo-Boundary Conditions: The Scour-Fill Dominated Jurassic Page Sandstone

NASA Astrophysics Data System (ADS)

Cardenas, B. T.; Kocurek, G.; Mohrig, D. C.; Swanson, T.

2017-12-01

The stratigraphic architecture of aeolian sandstones is thought to encode signals originating from both autogenic dune behavior and allogenic boundary conditions within which the dune field evolves. Mapping of outcrop-scale bounding surfaces and sets of cross-strata between these surfaces for the Jurassic Page Sandstone near Page, AZ, USA, demonstrates that dune autogenic behavior manifested in variable dune scour depth, whereas the dominant boundary conditions were antecedent topography and water-table elevation. At the study area, the Page Sandstone is 60 m thick and is separated from the underlying Navajo Sandstone by the J-2 regional unconformity, which shows meters of relief. Filling J-2 depressions are thin, climbing sets of cross-strata. In contrast, the overlying Page consists of packages of one to a few, meter-scale sets of cross-strata between the outcrop-scale bounding surfaces. These surfaces, marked by polygonal fractures and local overlying sabkha deposits, are regional in scale and correlated to high stands of the adjacent Carmel sea. Over the km-scale outcrop, the surfaces show erosional relief and packages of cross-strata are locally truncated. Notably absent within these cross-strata packages are early dune-field accumulations, interdune deposits, and apparent dune-climbing. These strata are interpreted to represent a scour-fill architecture created by migrating large dunes within a mature dry aeolian sand sea, in which early phases of dune-field construction have been cannibalized and dune fill of the deepest scours is recorded. At low angles of climb, set thickness is dominated by the component of scour-depth variation over the component resulting from the angle of climb. After filling of J-2 depressions, the Page consists of scour-fill accumulations formed during low stands. Carmel transgressions limited sediment availability, causing deflation to the water table and development of the regional bounding surfaces. Each subsequent fall of the

Paleolatitudes of the Tibetan Himalaya from primary and secondary magnetizations of Jurassic to Lower Cretaceous sedimentary rocks

NASA Astrophysics Data System (ADS)

Huang, Wentao; van Hinsbergen, Douwe J. J.; Dekkers, Mark J.; Garzanti, Eduardo; Dupont-Nivet, Guillaume; Lippert, Peter C.; Li, Xiaochun; Maffione, Marco; Langereis, Cor G.; Hu, Xiumian; Guo, Zhaojie; Kapp, Paul

2015-01-01

The Tibetan Himalaya represents the northernmost continental unit of the Indian plate that collided with Asia in the Cenozoic. Paleomagnetic studies on the Tibetan Himalaya can help constrain the dimension and paleogeography of "Greater India," the Indian plate lithosphere that subducted and underthrusted below Asia after initial collision. Here we present a paleomagnetic investigation of a Jurassic (limestones) and Lower Cretaceous (volcaniclastic sandstones) section of the Tibetan Himalaya. The limestones yielded positive fold test, showing a prefolding origin of the isolated remanent magnetizations. Detailed paleomagnetic analyses, rock magnetic tests, end-member modeling of acquisition curves of isothermal remanent magnetization, and petrographic investigation reveal that the magnetic carrier of the Jurassic limestones is authigenic magnetite, whereas the dominant magnetic carrier of the Lower Cretaceous volcaniclastic sandstones is detrital magnetite. Our observations lead us to conclude that the Jurassic limestones record a prefolding remagnetization, whereas the Lower Cretaceous volcaniclastic sandstones retain a primary remanence. The volcaniclastic sandstones yield an Early Cretaceous paleolatitude of 55.5°S [52.5°S, 58.6°S] for the Tibetan Himalaya, suggesting it was part of the Indian continent at that time. The size of "Greater India" during Jurassic time cannot be estimated from these limestones. Instead, a paleolatitude of the Tibetan Himalaya of 23.8°S [21.8°S, 26.1°S] during the remagnetization process is suggested. It is likely that the remagnetization, caused by the oxidation of early diagenetic pyrite to magnetite, was induced during 103-83 or 77-67 Ma. The inferred paleolatitudes at these two time intervals imply very different tectonic consequences for the Tibetan Himalaya.

Along strike behavior of the Tizi n' Firest fault during the Lower Jurassic rifting (Central High Atlas Carbonate basin, Morocco)

NASA Astrophysics Data System (ADS)

Sarih, S.; Quiquerez, A.; Allemand, P.; Garcia, J. P.; El Hariri, K.

2018-03-01

The purpose of this study is to document the along-strike early syn-rift history of the Lower Jurassic Carbonate basin of the Central High Atlas (Morocco) by combining sedimentological observations and high-resolution biostratigraphy. Six sections, each from the Sinemurian to the Upper Pliensbachian, were investigated along a 75 km-long transect at the hanging wall of a major fault of the Lower Jurassic Basin (i.e. the Tizi n' Firest fault). Depositional geometries of the early syn-rift deposits were reconstructed from the correlation between eight main timelines dated by biochronological markers for a time span covering about 6 Ma. Depocentre migration was examined and accommodation rates were calculated at the sub-zone timescale to discuss the along-strike-fault behavior of the Lower Jurassic basin formation. The early stages of extension are marked by contrasted along-strike variations in depositional geometry thickness, depocentre migration and accommodation rates, leading to the growth of three independent sub-basins (i.e. western, central, and eastern), ranging in size from 30 to 50 km, and displaying three contrasted tectono-sedimentary histories. Our results suggest that, during the early rifting phase, tectonic activity was not a continuous and progressive process evolving towards a rift climax stage, but rather a series of acceleration periods that alternated with periods of much reduced activity. The length of active fault segments is estimated at about 15-20 km, with a lifespan of a few ammonite sub-zones (> 2-3 Ma).

Paleogeographic evolution of the western Maghreb (Berberids) during the Jurassic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elmi, S.

1988-08-01

Several basins of the western Maghreb (northwest Africa) have been studied, taking into account their sedimentological and structural evolutions. Special attention is given to paleontological data (biostratigraphy, paleobiology, paleobiogeography). The paleogeographic pattern was the result of the differentiation in four stable blocks (Moroccan Meseta, Oran High Plains, Constantine block, Tunisian north-south ridge) which were developed between the Sahara craton and median strike-slips of the Tethys. This area, called the Berberids, was split by basins and furrows evolving during the Jurassic. Large, shallow, heterochronous initial carbonate platforms (Early Jurassic) were broken by local tectonic movements (tilting and rifting). A mature progradationmore » resulted from a rupture in the balance between carbonate production and subsidence. The result was the growth of more-or-less extended carbonate platforms along the basins margins during the Aalenian and Bajocia. From the late Bajocian, a large deltaic system prograded from the southwest and the west. Terrigenous input and large-scale tectonics provoked the filling of many basins. The southern and western areas became continental. In the north, carbonate series prograded on deltaic formations. A large, shallow platform developed on the southern rim of the Alpine Tethys. The tectonics of the basement on the southern rim of the Alpine Tethys. The tectonics of the basement became less important and sea level changes controlled the sedimentologic evolution. Bio- and chronostratigraphic correlations allow us to chart the main tectonic and eustatic events which occurred in the western Maghreb during the Jurassic.« less

Palaeo-equatorial temperatures and carbon-cycle evolution at the Triassic- Jurassic boundary: A stable isotope perspective from shallow-water carbonates from the UAE

NASA Astrophysics Data System (ADS)

Honig, M. R.; John, C. M.

2013-12-01

The Triassic-Jurassic boundary was marked by global changes including carbon-cycle perturbations and the opening of the Atlantic Ocean. These changes were accompanied by one of the major extinction events of the Phanerozoic. The carbon-cycle perturbations have been recorded in carbon isotope curves from bulk carbonates, organic carbon and fossil wood in several Tethyan locations and have been used for chemostratigraphic purposes. Here we present data from shallow-marine carbonates deposited on a homoclinal Middle Eastern carbonate ramp (United Arab Emirates). Our site was located at the equator throughout the Late Triassic and the Early Jurassic, and this study provides the first constraints of environmental changes at the low-latitudes for the Triassic-Jurassic boundary. Shallow-marine carbonate depositional systems are extremely sensitive to palaeoenvironmental changes and their usefulness for chemostratigraphy is being debated. However, the palaeogeographic location of the studied carbonate ramp gives us a unique insight into a tropical carbonate factory at a time of severe global change. Stable isotope measurements (carbon and oxygen) are being carried out on micrite, ooids and shell material along the Triassic-Jurassic boundary. The stable isotope results on micrite show a prominent negative shift in carbon isotope values of approximately 2 ‰ just below the inferred position of the Triassic-Jurassic boundary. A similar isotopic trend is also observed across the Tethys but with a range of amplitudes (from ~2 ‰ to ~4 ‰). These results seem to indicate that the neritic carbonates from our studied section can be used for chemostratigraphic purposes, and the amplitudes of the carbon isotope shifts provide critical constraints on the magnitude of carbon-cycle perturbations at low latitudes across the Triassic-Jurassic boundary. Seawater temperatures across the Triassic-Jurassic boundary will be constrained using the clumped isotope palaeo-thermometer applied

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

USGS Publications Warehouse

Billingsley, George H.; Block, Debra L.; 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

Evaluation of Navajo Community College. Final Report -- June 1970.

ERIC Educational Resources Information Center

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

Assessing the first institution of higher learning on an American Indian reservation in the U.S., this evaluation departs from the orthodox in that it addresses "need" areas observed during the Navajo Community College's first 12 months of operation (organization, budget and finance, communication, students and student services,…

Upper jurassic dinosaur egg from utah.

PubMed

Hirsch, K F; Stadtman, K L; Miller, W E; Madsen, J H

1989-03-31

The Upper Jurassic egg described here is the first known egg from the 100-million-year gap in the fossil record between Lower Jurassic (South Africa) and upper Lower Cretaceous (Utah). The discovery of the egg, which was found mixed in with thousands of dinosaur bones rather than in a nest, the pathological multilayering of the eggshell as found in modern and fossil reptilians, and the pliable condition of the eggshell at the time of burial indicate an oviducal retention of the egg at the time of burial.

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

Provenance of Jurassic sediments in the Hefei Basin, east-central China and the contribution of high-pressure and ultrahigh-pressure metamorphic rocks from the Dabie Shan

NASA Astrophysics Data System (ADS)

Li, Renwei; Wan, Yusheng; Cheng, Zhenyu; Zhou, Jianxiong; Li, Shuangying; Jin, Fuquan; Meng, Qingren; Li, Zhong; Jiang, Maosheng

2005-03-01

The provenance of the Jurassic sediments in the Hefei Basin is constrained by compositions of the detrital K-white micas and garnets, and SHRIMP dating of the detrital zircons, which can help to understand the evolution and to reconstruct the paleogeographic distribution of HP-UHP rocks in the Jurassic Dabie Shan. (1) For the oldest Mesozoic sediments at the bottom of the Fanghushan Formation ( J1), the predominance of the early Paleozoic and Luliang (1700-1900 Ma) zircons indicates a major source from the North China Block. However, Neoproterozoic zircons as the major component in other Jurassic sediments indicate that the source rocks were mainly derived from the exhumed Yangtze Block in the Dabie Shan. (2) The co-occurrence of high-Si phengites and Triassic zircons provides stratigraphic evidence that the first exposure of the UHP rocks at the Earth's surface in the Dabie Shan occurred in the Early Jurassic during deposition of the Fanghushan Formation. (3) From the east to the west of the Hefei Basin, there is a spatial variation in the compositions for detrital micas and garnets, and in the U-Pb ages of detrital zircons. Evidently, HP-UHP rocks were widely distributed at outcrop in the eastern Dabie Shan. In contrast, they were less important in the western Dabie Shan during the Jurassic.

Monitoring Drought Conditions in the Navajo Nation Using NASA Earth Observations

NASA Technical Reports Server (NTRS)

Ly, Vickie; Gao, Michael; Cary, Cheryl; Turnbull-Appell, Sophie; Surunis, Anton

2016-01-01

The Navajo Nation, a 65,700 sq km Native American territory located in the southwestern United States, has been increasingly impacted by severe drought events and changes in climate. These events are coupled with a lack of domestic water infrastructure and economic resources, leaving approximately one-third of the population without access to potable water in their homes. Current methods of monitoring drought are dependent on state-based monthly Standardized Precipitation Index value maps calculated by the Western Regional Climate Center. However, these maps do not provide the spatial resolution needed to illustrate differences in drought severity across the vast Nation. To better understand and monitor drought events and drought regime changes in the Navajo Nation, this project created a geodatabase of historical climate information specific to the area, and a decision support tool to calculate average Standardized Precipitation Index values for user-specified areas. The tool and geodatabase use Tropical Rainfall Monitoring Mission (TRMM) and Global Precipitation Monitor (GPM) observed precipitation data and Parameter-elevation Relationships on Independent Slopes Model modeled historical precipitation data, as well as NASA's modeled Land Data Assimilation Systems deep soil moisture, evaporation, and transpiration data products. The geodatabase and decision support tool will allow resource managers in the Navajo Nation to utilize current and future NASA Earth observation data for increased decision-making capacity regarding future climate change impact on water resources.

Gardening for Health: Patterns of Gardening and Fruit and Vegetable Consumption Among the Navajo.

PubMed

Ornelas, India J; Osterbauer, Katie; Woo, Lisa; Bishop, Sonia K; Deschenie, Desiree; Beresford, Shirley A A; Lombard, Kevin

2018-05-19

American Indians, including Navajo, are disproportionately affected by obesity and diabetes, in part due to diet-related health behaviors. The purpose of this study was to assess the patterns of gardening and fruit and vegetable (FV) consumption among residents in two communities on the Navajo Nation in order to inform a community gardening intervention. We analyzed survey data collected from participants in the Yéego Gardening study conducted in two communities in the Navajo Nation (N = 169). We found that 51% of the sample gardened, and on average participants gardened 8.9 times per month. Lack of time (53%) and financial barriers, such as gas for transportation or irrigation (51 and 49%, respectively), were reported as barriers to gardening. Most participants reported low levels of self-efficacy (80%) and behavioral capability (82%) related to gardening. Those with higher levels of gardening self-efficacy and behavioral capability reported more frequent gardening. Average daily FV consumption was 2.5 servings. Most participants reported high levels of self-efficacy to eat FV daily (64%) and high behavioral capability to prepare FV (66%). There was a positive association between FV consumption and gardening, with those gardening more than 4 times per month eating about 1 more serving of FV per day than those gardening 4 or fewer times per month. Further research is needed to better understand how gardening can increase fruit and vegetable availability and consumption among residents of the Navajo Nation.

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…

Middle to Late Jurassic Tectonic Evolution of the Klamath Mountains, California-Oregon

NASA Astrophysics Data System (ADS)

Harper, Gregory D.; Wright, James E.

1984-12-01

The geochronology, stratigraphy, and spatial relationships of Middle and Late Jurassic terranes of the Klamath Mountains strongly suggest that they were formed in a single west-facing magmatic arc built upon older accreted terranes. A Middle Jurassic arc complex is represented by the volcanic rocks of the western Hayfork terrane and consanguineous dioritic to peridotitic plutons. New U/Pb zircon dates indicate that the Middle Jurassic plutonic belt was active from 159 to 174 Ma and is much more extensive than previously thought. This plutonic belt became inactive just as the 157 Ma Josephine ophiolite, which lies west and structurally below the Middle Jurassic arc, was generated. Late Jurassic volcanic and plutonic arc rocks (Rogue Formation and Chetco intrusive complex) lie outboard and structurally beneath the Josephine ophiolite; U/Pb and K/Ar age data indicate that this arc complex is coeval with the Josephine ophiolite. Both the Late Jurassic arc complex and the Josephine ophiolite are overlain by the "Galice Formation," a Late Jurassic flysch sequence, and are intruded by 150 Ma dikes and sills. The following tectonic model is presented that accounts for the age and distribution of these terranes: a Middle Jurassic arc built on older accreted terranes undergoes rifting at 160 Ma, resulting in formation of a remnant arc/back-arc basin/island arc triad. This system collapsed during the Late Jurassic Nevadan Orogeny (150 Ma) and was strongly deformed and stacked into a series of east-dipping thrust sheets. Arc magmatism was active both before and after the Nevadan Orogeny, but virtually ceased at 140 Ma.

Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district

PubMed Central

2009-01-01

Background Decades of improper disposal of uranium-mining wastes on the Navajo Nation has resulted in adverse human and ecological health impacts as well as socio-cultural problems. As the Navajo people become increasingly aware of the contamination problems, there is a need to develop a risk-communication strategy to properly inform tribal members of the extent and severity of the health risks. To be most effective, this strategy needs to blend accepted risk-communication techniques with Navajo perspectives such that the strategy can be used at the community level to inform culturally- and toxicologically-relevant decisions about land and water use as well as mine-waste remediation. Objective The objective of this study was to develop GIS-based thematic maps as communication tools to clearly identify high risk exposure areas and offer alternatives to minimize public and ecological health impacts. Methods Thematic maps were produced that incorporated data derived from environmental sampling and public health surveys. The maps show the location and quality of unregulated water resources and identify regulated water sources that could be used as alternatives. In addition, the maps show the location of contaminated soil and sediment areas in which disturbance of surface deposits should be avoided. Preliminary feedback was collected from an informal Navajo working group to assess the clarity and efficacy of this proposed communication method. Results The working group found the maps to be both clear and effective, and made suggestions for improvements, such as the addition of more map features. The working group predicted that once the maps are presented to the public, water hauling and soil use behaviors will change, and dialogue with chapter officials will be initiated to accelerate further risk reduction efforts. Implications Because risk communication is complicated by language barriers, lack of infrastructure, and historical mistrust of non-Navajo researchers

Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district.

PubMed

deLemos, Jamie L; Brugge, Doug; Cajero, Miranda; Downs, Mallery; Durant, John L; George, Christine M; Henio-Adeky, Sarah; Nez, Teddy; Manning, Thomas; Rock, Tommy; Seschillie, Bess; Shuey, Chris; Lewis, Johnnye

2009-07-09

Decades of improper disposal of uranium-mining wastes on the Navajo Nation has resulted in adverse human and ecological health impacts as well as socio-cultural problems. As the Navajo people become increasingly aware of the contamination problems, there is a need to develop a risk-communication strategy to properly inform tribal members of the extent and severity of the health risks. To be most effective, this strategy needs to blend accepted risk-communication techniques with Navajo perspectives such that the strategy can be used at the community level to inform culturally- and toxicologically-relevant decisions about land and water use as well as mine-waste remediation. The objective of this study was to develop GIS-based thematic maps as communication tools to clearly identify high risk exposure areas and offer alternatives to minimize public and ecological health impacts. Thematic maps were produced that incorporated data derived from environmental sampling and public health surveys. The maps show the location and quality of unregulated water resources and identify regulated water sources that could be used as alternatives. In addition, the maps show the location of contaminated soil and sediment areas in which disturbance of surface deposits should be avoided. Preliminary feedback was collected from an informal Navajo working group to assess the clarity and efficacy of this proposed communication method. The working group found the maps to be both clear and effective, and made suggestions for improvements, such as the addition of more map features. The working group predicted that once the maps are presented to the public, water hauling and soil use behaviors will change, and dialogue with chapter officials will be initiated to accelerate further risk reduction efforts. Because risk communication is complicated by language barriers, lack of infrastructure, and historical mistrust of non-Navajo researchers, mapping provides an easily interpretable medium that

Examining early-diagenetic processes as a chief sink for carbonate in the aftermath of the Triassic-Jurassic crisis: Hettangian concretions of Muller Canyon, NV, USA

NASA Astrophysics Data System (ADS)

Ritterbush, K. A.; Loyd, S. J.; Corsetti, F. A.; Bottjer, D. J.; Berelson, W.

2015-12-01

Tectonic, climate, and biotic changes across the Triassic-Jurassic transition appear to have resulted in a "carbonate gap" in the rock record of many shallow marine environments. Ecological state changes documented in near-shore settings in both Tethys and Panthassa show an earliest Jurassic switch to sponge-dominated biosiliceous sedimentation regimes. The Sunrise Formation exposed in the Gabbs Valley Range of Nevada (USA) records a peculiar juxtaposition of Hettangian carbonate-rich strata that contain demosponge spicules as the primary bioclast. It is unclear 1) why biocalcifiers were not recorded in higher abundance in this near-shore back-arc basin setting; 2) why carbonates formed following a biosiliceous regime; and 3) what the lithology indicates about post-extinction marine geochemical dynamics. Detailed sedimentological, paleontological, and geochemical analyses were applied to a 20-m thick sequence of limestone and chert in the Muller Canyon area, which is the Auxiliary Stratotype for the Triassic/Jurassic boundary. Concretion anatomy, bioclast microfacies, and oxygen and carbon isotopic signatures all indicate the Hettangian limestones are chiefly diagenetic concretions that all formed very shallowly, some essentially at the sediment-water interface. We infer that local bottom waters and/or pore waters were supersaturated with respect to calcium carbonate and that this contributed to widespread concretion sedimentation independent of biomineralization. Ecological incumbency of the demosponge meadows may have been supported by concurrent augmentation of marine silica concentration and this apparently proved inhospitable to re-colonization of benthic biocalcifying macrofauna. Together the biotic and lithologic consequences of the extinction represent million-year scale ecological restructuring and highlight early diagenetic precipitation as a major sink in long-term regional carbonate cycling. Perhaps the widespread 'carbonate gap' is actually a gap in

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

Psychological effects of technological/human-caused environmental disasters: examination of the Navajo and uranium.

PubMed

Markstrom, Carol A; Charley, Perry H

2003-01-01

Disasters can be defined as catastrophic events that challenge the normal range of human coping ability. The technological/human-caused disaster, a classification of interest in this article, is attributable to human error or misjudgment. Lower socioeconomic status and race intersect in the heightened risk for technological/human-caused disasters among people of color. The experience of the Navajo with the uranium industry is argued to specifically be this type of a disaster with associated long-standing psychological impacts. The history of the Navajo with uranium mining and milling is reviewed with a discussion of the arduous efforts for compensation. The psychological impacts of this long-standing disaster among the Navajo are organized around major themes of: (a) human losses and bereavement, (b) environmental losses and contamination, (c) feelings of betrayal by government and mining and milling companies, (d) fears about current and future effects, (e) prolonged duration of psychological effects, (f) anxiety and depression, and (g) complicating factors of poverty and racism. The paper concludes with suggestions for culturally-appropriate education and intervention.

"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.…

Regional and temporal variability of melts during a Cordilleran magma pulse: Age and chemical evolution of the jurassic arc, eastern mojave desert, California

USGS Publications Warehouse

Barth, A.P.; Wooden, J.L.; Miller, David; Howard, Keith A.; Fox, Lydia; Schermer, Elizabeth R.; Jacobson, C.E.

2017-01-01

Intrusive rock sequences in the central and eastern Mojave Desert segment of the Jurassic Cordilleran arc of the western United States record regional and temporal variations in magmas generated during the second prominent pulse of Mesozoic continental arc magmatism. U/Pb zircon ages provide temporal control for describing variations in rock and zircon geochemistry that reflect differences in magma source components. These source signatures are discernible through mixing and fractionation processes associated with magma ascent and emplacement. The oldest well-dated Jurassic rocks defining initiation of the Jurassic pulse are a 183 Ma monzodiorite and a 181 Ma ignimbrite. Early to Middle Jurassic intrusive rocks comprising the main stage of magmatism include two high-K calc-alkalic groups: to the north, the deformed 183–172 Ma Fort Irwin sequence and contemporaneous rocks in the Granite and Clipper Mountains, and to the south, the 167–164 Ma Bullion sequence. A Late Jurassic suite of shoshonitic, alkali-calcic intrusive rocks, the Bristol Mountains sequence, ranges in age from 164 to 161 Ma and was emplaced as the pulse began to wane. Whole-rock and zircon trace-element geochemistry defines a compositionally coherent Jurassic arc with regional and secular variations in melt compositions. The arc evolved through the magma pulse by progressively greater input of old cratonic crust and lithospheric mantle into the arc magma system, synchronous with progressive regional crustal thickening.

Biostratigraphic restudy documents Triassic/Jurassic section in Georges Bank COST G-2 well

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cousminer, H.L.; Steinkraus, W.E.; Hall, R.E.

1984-04-01

In 1977, the COST G-2 well as drilled in Georges Bank, 132 mi (212 km) east of Nantucket Island to a total depth of 21,874 ft (6667 m). Biostratigraphic studies of 363 sidewall and conventional cores and 695 cutting samples resulted in a detailed zonation from the Late Jurassic to the present. Restudy of the original samples, as well as new preparations from previously unstudied core material, resulted in revision of the zonation of the Late Jurassic and older section. On the basis of our study of pollen and spores, dinoflagellates, nannofossils, and foraminifers, we revised the age sequence asmore » follows: 5856 ft (1785 m) Late Jurassic (Thithonian); 6000 ft (1829 m) Kimmeridgian; 6420 ft (1957 m) Oxfordian; 6818 ft (2078 m) Callovian; 8200 ft (2499 m) Bathonian; 9677 ft (2950 m) Bajocian; 14567 ft (4440 m) Norian (Late Triassic). Norian dinoflagellate cysts and Tasmanites sp. indicate that intermittent normal marine sedimentation was taking place on Georges Bank as early as Norian time, although most of the Triassic section (+14,500 ft or 4420 m to T.D.) interpreted as having been deposited under evaporitic sabkha-like conditions. The Norian dinoflagellates (Noricysta, Heibergella, Hebecysta, Suessia, Dapcodinium, and Rhombodella) include species common to both Arctic Canada and the Tethyan region, indicating a possible Late Triassic marine connection.« less

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

Petrotectonic characteristics, geochemistry, and U-Pb geochronology of Jurassic plutons in the Upper Magdalena Valley-Colombia: Implications on the evolution of magmatic arcs in the NW Andes

NASA Astrophysics Data System (ADS)

Rodríguez, G.; Arango, M. I.; Zapata, G.; Bermúdez, J. G.

2018-01-01

Field, petrographic, and geochemical characterization along with U-Pb zircon geochronology of the Jurassic plutons exposed in the Upper Magdalena Valley (Colombia) allowed recognizing distinct western and eastern suites formed in at least three magmatic pulses. The western plutons crop out between the eastern flank of the Central Cordillera and the Las Minas range, being limited by the Avirama and the Betania-El Agrado faults. The western suite comprises a quartz monzonite - quartz monzodiorite - quartz diorite series and subordinate monzogranites. Chemically, the rocks are high-K calc-alkaline I-type granitoids (some reaching the shoshonitic series) with metaluminous of magnesium affinity. Trace-element tectonic discrimination is consistent with magmatism in a continental arc environment. Most rocks of this suite crystallized between 195 and 186 Ma (Early Jurassic, Pliensbachian), but locally some plutons yielded younger ages between 182 and 179 Ma (Early Jurassic, Toarcian). The eastern suite crops out in the eastern margin of the Upper Magdalena Valley, east of the Betania - El Agrado fault. Plutons of this unit belong to the monzogranite series with rock types ranging between syenogranites and granodiorites. They are high-K calc-alkaline continental granitoids, some metaluminous and some peraluminous, related to I-type granites generated in a volcanic arc. Crystallization of the suite was between 173 and 169 Ma (Middle Jurassic, Aalenian-Bajocian), but locally these rocks contain zircon with earlier inherited ages related to the magmatic pulse of the western suite between 182 and 179 Ma (Early Jurassic, Toarcian). The evolution of the Jurassic plutons in the Upper Magdalena Valley is best explained by onset or increase in subduction erosion of the accretionary prism. This explains the eastward migration of the arc away from the trench. Subduction of prism sediments increased the water flux from the subducting slab, decreasing solidus temperatures, therefore

Chemical Remagnetization of Jurassic Carbonates and a Primary Paleolatitude of Lower Cretaceous Volcaniclastic Rocks of the Tibetan Himalaya

NASA Astrophysics Data System (ADS)

Huang, W.; Van Hinsbergen, D. J. J.; Dekkers, M. J.; Garzanti, E.; Dupont Nivet, G.; Lippert, P. C.; Li, X.; Maffione, M.; Langereis, C. G.; Hu, X.; Guo, Z.; Kapp, P. A.

2014-12-01

Paleolatitudes for the Tibetan Himalaya Zone based on paleomagnetic inclinations provide kinematic constraints of the passive northern Indian margin and the extent of 'Greater India' before the India-Asia collision. Here, we present a paleomagnetic investigation of the Jurassic (carbonates) to Lower Cretaceous (volcaniclastic rocks) Wölong section of the Tibetan Himalaya in the Everest region. The carbonates yield positive fold tests, suggesting that the remanent magnetizations have a pre-folding origin. However, detailed paleomagnetic analyses, rock magnetic tests, end-member modeling of acquisition curves of isothermal remanent magnetization, and petrographic studies reveal that the magnetic carrier of the Jurassic carbonates is authigenic magnetite, whereas the dominant magnetic carrier of the Lower Cretaceous volcaniclastic rocks is detrital magnetite. We conclude that the Jurassic carbonates were remagnetized, whereas the Lower Cretaceous volcaniclastics retain a primary remanence. We hypothesize that remagnetization of the Jurassic carbonates was probably caused by the oxidation of early diagenetic pyrite to magnetite within the time interval at ~86-84 Ma during the latest Cretaceous Normal Superchron and earliest deposition of Cretaceous oceanic red beds in the Tibetan Himalaya. The remagnetization of the limestones prevents determining the size of 'Greater India' during Jurassic time. Instead, a paleolatitude of the Tibetan Himalaya of 23.8±2.1° S at ~86-84 Ma is suggested. This value is lower than the expected paleolatitude of India from apparent polar wander path (APWP). The volcaniclastic rocks with the primary remanence, however, yielded a Lower Cretaceous paleolatitude of Tibetan Himalaya of 55.5±3° S, fitting well with the APWP of India.

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)

First Jurassic grasshopper (Insecta, Caelifera) from China.

PubMed

Gu, Jun-Jie; Yue, Yanli; Shi, Fuming; Tian, He; Ren, Dong

2016-09-20

Orthoptera is divided into two suborders, the Ensifera (katydids, crickets and mole crickets) and the Caelifera (grasshoppers and pygmy mole crickets). The earliest definitive caeliferans are those found in the Triassic (Bethoux & Ross 2005). The extinct caeliferan families, such as Locustopsidae and Locustavidae, may prove to be stem groups to some of the modern superfamilies (Grimaldi & Engel 2005). Locustopsidae is known from the Late Triassic or Early Jurassic to Late Cretaceous, consisting of two subfamilies (Gorochov et al. 2006). They are recorded from Europe, England, Russia, central Asia, China, Egypt, North America, Brazil and Australia. Up to now, Late Mesozoic fossil deposits of China has been reported plenty taxa of orthopterids, e.g. ensiferans, phasmatodeans, grylloblattids (Cui et al. 2012; Gu et al. 2010; Gu et al. 2012a; Gu et al. 2012b; Ren et al. 2012; Wang et al. 2014); but, with few caeliferans records, only four species, Pseudoacrida costata Lin 1982, Mesolocustopsis sinica Hong 1990, Tachacris stenosis Lin 1977 and T. turgis Lin 1980, were reported from the Early Cretaceous of Ningxia, Shandong, Yunnan and Zhejiang of China.

Peri-equatorial paleolatitudes for Jurassic radiolarian cherts of Greece

USGS Publications Warehouse

Aiello, I.W.; Hagstrum, J.T.; Principi, G.

2008-01-01

Radiolarian-rich sediments dominated pelagic deposition over large portions of the Tethys Ocean during middle to late Jurassic time as shown by extensive bedded chert sequences found in both continental margin and ophiolite units of the Mediterranean region. Which paleoceanographic mechanisms and paleotectonic setting favored radiolarian deposition during the Jurassic, and the nature of a Tethys-wide change from biosiliceous to biocalcareous (mainly nannofossil) deposition at the beginning of Cretaceous time, have remained open questions. Previous paleomagnetic analyses of Jurassic red radiolarian cherts in the Italian Apennines indicate that radiolarian deposition occurred at low peri-equatorial latitudes, similar to modern day deposition of radiolarian-rich sediments within equatorial zones of high biologic productivity. To test this result for other sectors of the Mediterranean region, we undertook paleomagnetic study of Mesozoic (mostly middle to upper Jurassic) red radiolarian cherts within the Aegean region on the Peloponnesus and in continental Greece. Sampled units are from the Sub-Pelagonian Zone on the Argolis Peninsula, the Pindos-Olonos Zone on the Koroni Peninsula, near Karpenissi in central Greece, and the Ionian Zone in the Varathi area of northwestern Greece. Thermal demagnetization of samples from all sections removed low-temperature viscous and moderate-temperature overprint magnetizations that fail the available fold tests. At Argolis and Koroni, however, the cherts carry a third high-temperature magnetization that generally exhibits a polarity stratigraphy and passes the available fold tests. We interpret the high-temperature component to be the primary magnetization acquired during chert deposition and early diagenesis. At Kandhia and Koliaky (Argolis), the primary declinations and previous results indicate clockwise vertical-axis rotations of ??? 40?? relative to "stable" Europe. Due to ambiguities in hemispheric origin (N or S) and thus

Influence of climate change and marine chemistry on ecological shifts following the Triassic/Jurassic mass extinction

NASA Astrophysics Data System (ADS)

Ritterbush, K. A.; West, A. J.; Berelson, W.; Rosas, S.; Bottjer, D. J.; Yager, J. A.; Corsetti, F. A.

2014-12-01

Two aspects of the Triassic/Jurassic transition that seem incongruous are increasing warming and increasing ecological dominance by siliceous sponges on shallow shelves. Warming is interpreted from proxy data showing increased atmospheric carbon dioxide concentrations associated with eruption pulses of the Central Atlantic Province (CAMP) basalts across rifting Pangea. Post-extinction ecological dominance by siliceous sponges is found in recent field investigations of Nevada and Peru, and literature on the Austrian Alps. Whereas evidence from the Panthalassan siliceous sponge ramps of the early Jurassic clearly records deposition on sub- and tropical shallow shelves (a warm environment), modern sponge occupations of comparable intensity exist only in deep and cold environments. Resolving this apparent contrast requires consideration of silica cycling. Silica is a limiting nutrient for siliceous sponges, and the post-extinction sponges of the earliest Jurassic show desmid spicule morphologies matching modern phenotypic indicators of high silica concentration. During the Triassic the major documented biosiliceous sink was radiolarian deep sea chert deposits despite a major species-level turnover at the extinction. Diatoms did not exist in the Triassic. A major alteration to silica cycling in the early Jurassic could have resulted from increased terrigenous supply for two reasons: increased atmospheric carbon dioxide would likely intensify continental weathering, and the extensive flood basalts produced an easily-weathered silica source. Simple box model calculations allow consideration of supply vs demand, and of the pace of possible changes. Potential weathering rates of silica are contrasted with recent published data on sponge silica sequestration, showing that the presence of the CAMP basalts alone could support increased sponge abundance across tropical carbonate shelves. Estimates of doubling and residence times in a simple one-box model show that the change in

New Fossil Evidence on the Sister-Group of Mammals and Early Mesozoic Faunal Distributions

NASA Astrophysics Data System (ADS)

Shubin, Neil H.; Crompton, A. W.; Sues, Hans-Dieter; Olsen, Paul E.

1991-03-01

Newly discovered remains of highly advanced mammal-like reptiles (Cynodontia: Tritheledontidae) from the Early Jurassic of Nova Scotia, Canada, have revealed that aspects of the characteristic mammalian occlusal pattern are primitive. Mammals and tritheledontids share an homologous pattern of occlusion that is not seen in other cynodonts. The new tritheledontids represent the first definite record of this family from North America. The extreme similarity of North American and African tritheledontids supports the hypothesis that the global distribution of terrestrial tetrapods was homogeneous in the Early Jurassic. This Early Jurassic cosmopolitanism represents the continuation of a trend toward increased global homogeneity among terrestrial tetrapod communities that began in the late Paleozoic.

The first fossil spider (Araneae: Palpimanoidea) from the Lower Jurassic (Grimmen, Germany).

PubMed

Selden, Paul A; Dunlop, Jason A

2014-12-11

The first Lower Jurassic (Lias) spider is described as Seppo koponeni n. gen. & n. sp. from a single female specimen from Grimmen, Germany. It most likely belongs to the Palpimanoidea, on account of the presence of cheliceral peg teeth and other features consistent with palpimanoid families, though its familial placement is uncertain. Its presence in the region at that time concurs with ideas about the more widespread presence of palpimanoids across the world in the early Mesozoic, before the break-up of Pangaea.

American Indian Bilingual Education. Navajo Reading Study Progress Report No. 24.

ERIC Educational Resources Information Center

Spolsky, Bernard

Bilingual education programs have been established in such Native American languages as Aleut, Yupik, Tlingit, Haida, Athabaskan, Cherokee, Lakota, Navajo, Papago, Pomo, Passamaquoddy, Seminole, Tewa, and Zuni. These programs include the: Choctaw Bilingual Education Program, Northern Cheyenne Bilingual Education Program, Lakota Bilingual Education…

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

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.

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…

"When I am lonely the mountains call me": the impact of sacred geography on Navajo psychological well being.

PubMed

Griffin-Pierce, T

1997-01-01

As we approach the twenty-first century, sacred geography continues to have a profound impact on Navajo psychological well being. This article explores the extent of the Navajo's bond with their homeland through an emphasis on orderly conditions in their world view, myths, and ceremonies. When traditional Navajos leave their homeland to pursue educational and professional endeavors or to seek biomedical treatment, a sense of emotional dislocation can undermine their success. The emotional trauma goes far beyond mere homesickness because it is based on an often unconscious sense of having violated the moral order of the universe. It is essential that mental health professionals respond with sensitivity to this issue by understanding the extent to which the sacred mountains and other landforms serve as a vital source of spiritual strength.

A new basal sauropod from the pre-Toarcian Jurassic of South Africa: evidence of niche-partitioning at the sauropodomorph–sauropod boundary?

PubMed Central

McPhee, Blair W.; Bonnan, Matthew F.; Yates, Adam M.; Neveling, Johann; Choiniere, Jonah N.

2015-01-01

The early evolution of sauropod dinosaurs remains poorly understood, with a paucity of unequivocal sauropod taxa known from the first twenty million years of the Jurassic. Recently, the Early Jurassic of South Africa has yielded an assemblage of dental and post-cranial remains displaying a more apomorphic character suite than any other similarly aged sauropodomorph. These remains are interpreted as a new species of basal sauropod and recovered cladistically as the sister taxon to Vulcanodon +more derived Sauropoda, underscoring its importance for our understanding of this pivotal period of sauropod evolution. Key changes in the dentition, axial skeleton and forelimb of this new species suggest a genuine functional distinction occurring at the sauropodiform-sauropod boundary. With reference to these changes, we propose a scenario in which interdependent refinements of the locomotory and feeding apparatus occurred in tandem with, or were effected by, restrictions in the amount of vertical forage initially available to the earliest sauropods. The hypothesized instance of niche-partitioning between basal sauropodan taxa and higher-browsing non-sauropodan sauropodomorphs may partially explain the rarity of true sauropods in the basal rocks of the Jurassic, while having the added corollary of couching the origins of Sauropoda in terms of an ecologically delimited ‘event’. PMID:26288028

Convergence in Thunniform Anatomy in Lamnid Sharks and Jurassic Ichthyosaurs.

PubMed

Lingham-Soliar, Theagarten

2016-12-01

Among extinct ichthyosaurs the Jurassic forms Ichthyosaurus and Stenopterygius share a number of anatomical specializations with lamnid sharks, characterized in the white shark, Carcharodon carcharias These features allow their inclusion within the mode of high-speed thunniform swimming to which only two other equally distinctive phylogenetic groups belong, tuna and dolphins-a striking testaments to evolutionary convergence. Jurassic ichthyosaurs evolved from reptiles that had returned to the sea (secondarily adapted) about 250 million years ago (MYA) while lamnid sharks evolved about 50 MYA from early cartilaginous fishes (originating ca. 400 MYA). Their shared independently evolved anatomical characteristics are discussed. These include a deep tear-drop body shape that helped initially define members as thunniform swimmers. Later, other critical structural characteristics were discovered such as the crossed-fiber architecture of the skin, high-speed adapted dorsal and caudal fins, a caudal peduncle and series of ligaments to enable transmission of power from the musculature located anteriorly to the caudal fin. Both groups also share a similar chemistry of the dermal fibers, i.e., the scleroprotein collagen. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Jurassic subduction initiation in the western and central Neo-Tethys and the origin of the Balkan ophiolites

NASA Astrophysics Data System (ADS)

Van Hinsbergen, D. J. J.; Maffione, M.

2017-12-01

Jurassic subduction initiation in the Neo-Tethys Ocean was the first, critical step of a long tectonic process that eventually led to the collision of the Adria-Africa and Eurasia plates and the formation of a 6000 km long Alpine orogenic belt spanning from the Balkan Peninsula to Iran. Investigating the process of subduction initiation in the Neo-Tethys during the Jurassic is crucial to (i) reconstruct the complex geological evolution of this orogen from its initial stages, and (ii) shed new lights over the enigmatic kinematics and driving mechanisms of subduction initiation. Records of the initial closure of the Neo-Tethys are today preserved in a fragmented belt of Middle Jurassic ophiolites (170-160 Ma) distributed above the Alpine orogen. In particular, the well-preserved and extensively studied ophiolites of the Balkan Peninsula offer a unique chance to study the mechanisms leading to the closure of the western domain of the Neo-Tethys. Here we provide the first quantitative constraints on the geometry of the Jurassic Neo-Tethyan subduction system using a net tectonic rotation analysis based on paleomagnetic and structural geological data from the sheeted dyke complexes of various ophiolites of Serbia (Maljen, Ibar) and Greece (Othris, Pindos, Vourinos, Guevgueli). Our results show that closure of the western Neo-Tethys was accommodated by two subduction zones, one intra-oceanic, formed at the N-S trending Neo-Tethyan ridge, the other initiated at the European passive margin and curving southward from a N-S to a NW-SE direction following the shape of the passive margin. We propose that these two subduction zones formed upon propagation of subduction(s) initiated in the central Neo-Tethys (modern Turkey) in the late Early Jurassic ( 185-180 Ma).

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

A synthesis of Jurassic and Early Cretaceous crustal evolution along the southern margin of the Arctic Alaska–Chukotka microplate and implications for defining tectonic boundaries active during opening of Arctic Ocean basins

USGS Publications Warehouse

Till, Alison B.

2016-01-01

A synthesis of Late Jurassic and Early Cretaceous collision-related metamorphic events in the Arctic Alaska–Chukotka microplate clarifies its likely movement history during opening of the Amerasian and Canada basins. Comprehensive tectonic reconstructions of basin opening have been problematic, in part, because of the large size of the microplate, uncertainties in the location and kinematics of structures bounding the microplate, and lack of information on its internal deformation history. Many reconstructions have treated Arctic Alaska and Chukotka as a single crustal entity largely on the basis of similarities in their Mesozoic structural trends and similar late Proterozoic and early Paleozoic histories. Others have located Chukotka near Siberia during the Triassic and Jurassic, on the basis of detrital zircon age populations, and suggested that it was Arctic Alaska alone that rotated. The Mesozoic metamorphic histories of Arctic Alaska and Chukotka can be used to test the validity of these two approaches.A synthesis of the distribution, character, and timing of metamorphic events reveals substantial differences in the histories of the southern margin of the microplate in Chukotka in comparison to Arctic Alaska and places specific limitations on tectonic reconstructions. During the Late Jurassic and earliest Cretaceous, the Arctic Alaska margin was subducted to the south, while the Chukotka margin was the upper plate of a north-dipping subduction zone or a zone of transpression. An early Aptian blueschist- and greenschist-facies belt records the most profound crustal thickening event in the evolution of the orogen. It may have resulted in thicknesses of 50–60 km and was likely the cause of flexural subsidence in the foredeep of the Brooks Range. This event involved northern Alaska and northeasternmost Chukotka; it did not involve central and western Chukotka. Arctic Alaska and Chukotka evolved separately until the Aptian thickening event, which was likely a

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

Navajo Coal Combustion and Respiratory Health Near Shiprock, New Mexico

DOE PAGES

Bunnell, Joseph E.; Garcia, Linda V.; Furst, Jill M.; ...

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

Fish faunas from the Late Jurassic (Tithonian) Vaca Muerta Formation of Argentina: One of the most important Jurassic marine ichthyofaunas of Gondwana

NASA Astrophysics Data System (ADS)

Gouiric-Cavalli, Soledad; Cione, Alberto Luis

2015-11-01

The marine deposits of the Vaca Muerta Formation (Tithonian-Berriasian) houses one of the most diverse Late Jurassic ichthyofaunas of Gondwana. However, most of the specimens remain undescribed. Jurassic fishes have been recovered from several localities at Neuquén Province (i.e., Picún Leufú, Plaza Huincul, Cerro Lotena, Portada Las Lajas, Los Catutos, and Arroyo Covunco) but also from Mendoza Province (i.e., La Valenciana, Los Molles, and Arroyo del Cajón Grande). Presently, the fish fauna of Los Catutos, near Zapala city (Neuquén Province), has yielded the highest number of specimens, which are taxonomically and morphologically diverse. At Los Catutos locality, the Vaca Muerta Formation is represented by the Los Catutos Member, which is considered the only lithographic limestones known in the Southern Hemisphere. Here, we review the Tithonian fish faunas from the Vaca Muerta Formation. During Late Jurassic times, the actual Argentinian territory could have been a morphological diversification center, at least for some actinopterygian groups. The apparently lower species diversity recorded in marine Jurassic ichthyofaunas of Argentina (and some Gondwanan countries) in comparison with Chilean and European fish faunas could be related to the fish paleontological research history in Gondwana and the low number of detailed studies of most of specimens recorded.

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…

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)

Associations of Circulating Oxidized LDL and Conventional Biomarkers of Cardiovascular Disease in a Cross-Sectional Study of the Navajo Population

PubMed Central

Harmon, Molly E.; Campen, Matthew J.; Miller, Curtis; Shuey, Chris; Cajero, Miranda; Lucas, Selita; Pacheco, Bernadette; Erdei, Esther; Ramone, Sandy; Nez, Teddy; Lewis, Johnnye

2016-01-01

The prevalences of cardiovascular disease (CVD) and type 2 diabetes (T2D) have increased among the Navajo Native American community in recent decades. Oxidized low-density lipoprotein (oxLDL) is a novel CVD biomarker that has never been assessed in the Navajo population. We examined the relationship of oxLDL to conventional CVD and T2D risk factors and biomarkers in a cross-sectional population of Navajo participants. This cross-sectional study included 252 participants from 20 Navajo communities from the Diné Network for Environmental Health Project. Plasma samples were tested for oxLDL levels by a sandwich enzyme-linked immunosorbent assay. Univariate and multivariate analyses were used to determine the relationship of oxLDL and oxidized- to non-oxidized lipoprotein ratios to glycated hemoglobin (HbA1c), C-reactive protein (CRP), interleukin 6 (IL6) and demographic and health variables. Type 2 diabetes, hypertension and obesity are very prevalent in this Navajo population. HbA1c, CRP, body mass index (BMI), high-density lipoprotein, and triglycerides were at levels that may increase risk for CVD and T2D. Median oxLDL level was 47 (36.8–57) U/L. Correlational analysis showed that although oxLDL alone was not associated with HbA1c, oxLDL/HDL, oxLDL/LDL and CRP were significantly associated with HbA1c and glucose. OxLDL, oxLDL/HDL and oxLDL/LDL were significantly associated with CRP. Multivariate analysis showed that triglycerides were a common and strong predictor of oxLDL, oxLDL/HDL and oxLDL/LDL. OxLDL was trended with HbA1c and glucose but did not reach significance, however, HbA1c was an independent predictor of OxLDL/HDL. CRP trended with oxLDL/HDL and was a weak predictor of oxLDL/LDL. This Navajo subset appears to have oxLDL levels comparable to subjects without evidence of CVD reported in other studies. The high prevalence of T2D, hypertension and obesity along with abnormal levels of other biomarkers including HbA1c indicate that the Navajo population

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…

Regional hydrogeology of the Navajo and Hopi Indian reservations, Arizona, New Mexico, and Utah, with a section on vegetation

USGS Publications Warehouse

Cooley, M.E.; Harshbarger, J.W.; Akers, J.P.; Hardt, W.F.; Hicks, O.N.

1969-01-01

The Navajo and Hopi Indian Reservations have an area of about 25,000 square miles and are in the south-central part of the Colorado Plateaus physiographic province. The reservations are underlain by sedimentary rocks that range in age from Cambrian to Tertiary, but Permian and younger rocks are exposed in about 95 percent of the area. Igneous and metamorphic basement rocks of Precambrian age underlie the sedimentary rocks at depths ranging from 1,000 to 10,000 feet. Much of the area is mantled by thin alluvial, eolian, and terrace deposits, which mainly are 10 to 50 feet thick.The Navajo country was a part of the eastern shelf area of the Cordilleran geosyncline during Paleozoic and Early Triassic time and part of the southwestern shelf area of the Rocky Mountain geosyncline in Cretaceous time. The shelf areas were inundated frequently by seas that extended from the central parts of the geosynclines. As a result, complex intertonguing and rapid facies changes are prevalent in the sedimentary rocks and form some of the principal controls on the ground-water hydrology. Regional uplift beginning in Late Cretaceous time , destroyed. the Rocky Mountain geosyncline and formed the structural basius that influenced sedimentation and erosion throughout Cenozoic time.

Equatorial seawater temperatures and latitudinal temperature gradients during the Middle to Late Jurassic: the stable isotope record of brachiopods and oysters from Gebel Maghara, Egypt

NASA Astrophysics Data System (ADS)

Alberti, Matthias; Fürsich, Franz T.; Abdelhady, Ahmed A.; Andersen, Nils

2017-04-01

The Jurassic climate has traditionally been described as equable, warmer than today, with weak latitudinal temperature gradients, and no polar glaciations. This view changed over the last decades with studies pointing to distinct climate fluctuations and the occasional presence of polar ice caps. Most of these temperature reconstructions are based on stable isotope analyses of fossil shells from Europe. Additional data from other parts of the world is slowly completing the picture. Gebel Maghara in the northern Sinai Peninsula of Egypt exposes a thick Jurassic succession. After a phase of terrestrial sedimentation in the Early Jurassic, marine conditions dominated since the end of the Aalenian. The stable isotope (δ18O, δ13C) composition of brachiopod and oyster shells was used to reconstruct seawater temperatures from the Bajocian to the Kimmeridgian at a palaeolatitude of ca. 3°N. Throughout this time interval, temperatures were comparatively constant aorund an average of 25.7°C. Slightly warmer conditions existed in the Early Bathonian ( 27.0°C), while the Kimmeridgian shows the lowest temperatures ( 24.3°C). The seasonality has been reconstructed with the help of high-resolution sampling of two oyster shells and was found to be very low (<2°C) as can be expected for a tropical palaeolatitude. A comparison of the results from Egypt with literature data enabled the reconstruction of latitudinal temperature gradients. During the Middle Jurassic, this gradient was much steeper than previously expected and comparable to today. During the Kimmeridgian, temperatures in Europe were generally warmer leading to weaker latitudinal gradients. Based on currently used estimates for the δ18O value of seawater during the Jurassic, reconstructed water temperatures for localities above the thermocline in Egypt and Europe were mostly lower than Recent sea-surface temperatures. These results improve our understanding of the Jurassic climate and its influence on marine

Climatic fluctuations and seasonality during the Late Jurassic (Oxfordian-Early Kimmeridgian) inferred from δ18O of Paris Basin oyster shells

NASA Astrophysics Data System (ADS)

Brigaud, Benjamin; Pucéat, Emmanuelle; Pellenard, Pierre; Vincent, Benoît; Joachimski, Michael M.

2008-08-01

Oxygen isotope data from biostratigraphically well-dated oyster shells from the Late Jurassic of the eastern Paris Basin are used to reconstruct the thermal evolution of western Tethyan surface waters during the Early Oxfordian-Early Kimmeridgian interval. Seventy eight oyster shells were carefully screened for potential diagenetic alteration using cathodoluminescence microscopy. Isotope analyses were performed on non-luminescent parts of shells (n = 264). Intra-shell δ18O variability was estimated by microsampling along a transect perpendicular to the growth lines of the largest oyster shell. The sinusoidal distribution of the δ18O values along this transect and the dependence of the amplitude of variations with bathymetry suggest that intra-shell variability reflects seasonal variations of temperature and/or salinity. Average amplitudes of about 5 °C in shallow water environments and of about 2-3 °C in deeper offshore environments are calculated. These amplitudes reflect minimum seasonal temperature variation. Our new data allow to constrain existing paleotemperature trends established from fish tooth and belemnite δ18O data and are in better agreement with paleontological data. More specifically, a warming trend of about 3 °C is reconstructed for oceanic surface waters during the Early to Middle Oxfordian transition, with maximum temperatures reaching 24 °C in the transversarium Zone (late Middle Oxfordian). From the transversarium Zone to the bimmamatum Zone, a cooling of about 7 °C is indicated, whereas from the bimmamatum Zone, temperatures increased again by about 7 °C to reach 24 °C in average during the cymodoce Zone (Early Kimmeridgian).

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…

Incorporating Dine' Perspectives in Assessing Temporal and Spatial Changes of Contaminants after the Gold King Mine Spill in Navajo Agricultural Communities

NASA Astrophysics Data System (ADS)

Chief, K.; Beamer, P.; Ingram, J.; Billheimer, D.; Torabzadehkhorasani, E.; Settimo, A.; Ornelas, Y.

2017-12-01

On August 5, 2015, 3 million gallons of acid mine drainage was released from the Gold King Mine, eventually reaching the San Juan River on the Navajo Nation. Navajos have subsistence livelihoods and strong cultural and spiritual connections to the San Juan River. Building on established partnerships with the Navajo Nation, a team from the University of Arizona and Northern Arizona University held three public listening sessions and a People's Teach-in in three Navajo communities. Navajo representatives also came to the university to share their perspectives. The university team immersed themselves in cultural learning through community advisors who taught on traditional knowledge and ways of knowing. One response at the People's Teach-In was "The San Juan represents a male river in Diné culture. To me the river is a life giving force to the Diné people and ecosystems." This traditional knowledge informed the team on how to address the communities' concern of assessing the spatial and temporal changes of lead and arsenic from the Spill within one year. Focus groups were held to understand how people used the San Juan River and it revealed over 40 different activities besides recreation. River water and sediment, irrigation water and sediment, agricultural soil and well water were collected in November 2015, March and June 2016 and household samples in August 2016. In this talk, we will present water quality and sediment results of water samples collected along the San Juan River on the Navajo Nation. The results of this investigation will be used in the future to develop a community-based intervention, designed to: a) prevent potentially harmful exposures based on actual measured risk, and/or b) effectively communicate long-term risks from the Gold King Mine.

The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

NASA Astrophysics Data System (ADS)

Zell, Patrick; Crame, J. Alistair; Stinnesbeck, Wolfgang; Beckmann, Seija

2015-07-01

In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian-lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic-earliest Cretaceous, between Mexico and the Antarctic Realm.

Mesozoic authigenic carbonate deposition in the Arctic: Do glendonites record gas hydrate destabilization during the Jurassic?

NASA Astrophysics Data System (ADS)

Morales, Chloe; Suan, Guillaume; Wierzbowski, Hubert; Rogov, Mikhail; Teichert, Barbara; Kienhuis, Michiel V. M.; Polerecky, Lubos; Middelburg, Jack B. M.; Reichart, Gert-Jan; van de Schootbrugge, Bas

2015-04-01

Glendonites are calcite pseudomorphs after ikaite, an unstable hydrated calcium carbonate mineral. Because present-day ikaite occurs predominantly in sub-polar environments and is unstable at warm temperatures, glendonites have been used as an indicator of near-freezing conditions throughout Earth history. Ikaite has also been observed in cold deep-sea environments like the Gulf of Mexico, the Japan Trench, and the Zaire Fan where their formation is possibly governed by other parameters. The description of glendonites in Paleocene-Eocene sediments of Svalbard, and Early Jurassic (Pliensbachian) deposits of northern Germany, however questions the role of temperature on ikaite precipitation (Spielhagen and Tripati, 2009; Teichert and Luppold, 2013). Anomalously low carbon isotope values of Jurassic glendonites point to the involvement of methane as a possible carbon source for ikaite/glendonite formation. Terrestrial organic matter degradation is also frequently evoked as a potential source of carbon. The involved bio- and geochemical processes remains thus not well constrained. Here we present new geochemical data of a large number of glendonites specimens from the Lower and Middle Jurassic of northern Siberia and the Lena river middle flows (Bajocian, Bathonian, Pliensbachian). Carbon and oxygen isotopic values show comparable trends between the different sections. Bulk glendonites δ13C and δ18O values vary from 0.0 to -44.5o and -15.0 to -0.8 respectively and show a negative correlation. Some samples display similar low δ13C values as the Pliensbachian glendonites of Germany (Teichert and Luppold, 2013), suggesting thermogenic and/or biogenic methane sources. The range of carbon isotope values is comparable to those observed at other methane seeps deposits. Further investigations are needed to better constrain the carbon cycle in these particular environmental conditions. The role of microbial communities into ikaite/glendonite formation equally needs to be

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…

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

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-29

... Permits authorized by OMB Control Number 1076-0162. This information collection expires May 31, 2013.... Data OMB Control Number: 1076-0162. Title: Navajo Partitioned Lands Grazing Permits, 25 CFR 161. Brief...

Cross Country, Rodeo, Archery: Navajo Athletic Programs Give Students Running Start

ERIC Educational Resources Information Center

Johnson, Natasha Kaye

2009-01-01

While tribal college athletic programs were not designed to market the colleges, there is no denying they have generated positive attention and have perhaps even helped to highlight the colleges' purpose. Dine College and Navajo Technical College are among a handful of tribal colleges who have made athletic programs a priority. They have since…

Paleohydrologic controls on soft-sediment deformation in the Navajo Sandstone

NASA Astrophysics Data System (ADS)

Bryant, Gerald; Cushman, Robert; Nick, Kevin; Miall, Andrew

2016-10-01

Many workers have noted the presence of contorted cross-strata in the Navajo Sandstone and other ancient eolianites, and have recognized their significance as indicators of sediment saturation during the accumulation history. Horowitz (1982) proposed a general model for the production of such features in ancient ergs by episodic, seismically induced liquefaction of accumulated sand. A key feature of that popular model is the prevalence of a flat water table, characteristic of a hyper-arid climatic regime, during deformation. Under arid climatic conditions, the water table is established by regional flow and liquefaction is limited to the saturated regions below the level of interdune troughs. However, various paleohydrological indicators from Navajo Sandstone outcrops point toward a broader range of water table configurations during the deformation history of that eolianite. Some outcrops reveal extensive deformation complexes that do not appear to have extended to the contemporary depositional surface. These km-scale zones of deformation, affecting multiple sets of cross-strata, and grading upward into undeformed crossbeds may represent deep water table conditions, coupled with high intensity triggers, which produced exclusively intrastratal deformation. Such occurrences contrast with smaller-scale complexes formed within the zone of interaction between the products of soft-sediment deformation and surface processes of deposition and erosion. The Horowitz model targets the smaller-scale deformation morphologies produced in this near-surface environment. This study examines the implications of a wet climatic regime for the Horowitz deformation model. It demonstrates how a contoured water table, characteristic of humid climates, may have facilitated deformation within active bedforms, as well as in the accumulation. Intra-dune deformation would enable deflation of deformation features during the normal course of dune migration, more parsimoniously accounting for

Molecular composition and ultrastructure of Jurassic paravian feathers

PubMed Central

Lindgren, Johan; Sjövall, Peter; Carney, Ryan M.; Cincotta, Aude; Uvdal, Per; Hutcheson, Steven W.; Gustafsson, Ola; Lefèvre, Ulysse; Escuillié, François; Heimdal, Jimmy; Engdahl, Anders; Gren, Johan A.; Kear, Benjamin P.; Wakamatsu, Kazumasa; Yans, Johan; Godefroit, Pascal

2015-01-01

Feathers are amongst the most complex epidermal structures known, and they have a well-documented evolutionary trajectory across non-avian dinosaurs and basal birds. Moreover, melanosome-like microbodies preserved in association with fossil plumage have been used to reconstruct original colour, behaviour and physiology. However, these putative ancient melanosomes might alternatively represent microorganismal residues, a conflicting interpretation compounded by a lack of unambiguous chemical data. We therefore used sensitive molecular imaging, supported by multiple independent analytical tests, to demonstrate that the filamentous epidermal appendages in a new specimen of the Jurassic paravian Anchiornis comprise remnant eumelanosomes and fibril-like microstructures, preserved as endogenous eumelanin and authigenic calcium phosphate. These results provide novel insights into the early evolution of feathers at the sub-cellular level, and unequivocally determine that melanosomes can be preserved in fossil feathers. PMID:26311035

Geomechanical Modeling of Deformation Banding in the Navajo Sandstone, San Rafael Monocline, Utah

NASA Astrophysics Data System (ADS)

Gutierrez, M.; Sundal, A.; Petrie, E. S.

2017-12-01

Deformation bands are ubiquitous geological features in many types of rocks. Depending on their micro-structure, they can act either as conduits or barriers to fluid flow. Given the significant roles deformation bands play in fluid flow and chemical transport in rocks, it is important to develop fundamental understanding of their origin, and their characteristics as they relate with the host rock properties and their depositional and structural-geological history. We present a forward-modeling technique based on the geomechanical Bifurcation Theory (BT) to predict the formation of deformation bands in sandstone. According to BT, the formation of deformation bands is a result of strain location, which in turn stems from instability in the stress-strain response of materials during loading. Due to bifurcation, a material which undergoes homogeneous deformation can reach a point at which the material experiences instability and deformation starts to become non-homogenous. We implemented BT in the commercially-available geomechanical code FLAC (Fast Langragian Analysis of Continua) and applied it in the field-scale modeling of deformation banding in the Navajo Sandstone in the San Rafael Monocline in Utah induced by fault propagation folding. The results show that geomechanical modeling using BT has a powerful potential to simulate the physical processes in the formation of deformation banding in rocks. Predicted deformation bands, specifically the pervasive bedding-parallel bands in the Navajo sandstone formation, normal faulting in the upper limb and reverse faulting in the lower limb, are generally in agreement with field observations. Predictions indicate that the pervasive bedding-parallel bands in the Navajo Sandstone are transitional compaction-shear bands with alternating zones of volumetric compaction and dilation. These predictions are consistent with petrographic analysis of thin sections of rock samples from the Navajo Sandstone. The most important

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

... Budget (OMB) for renewal. The information collection is currently authorized by OMB Control Number 1076... the following information collection activity. III. Data OMB Control Number: 1076-0162. Title: Navajo...

Results of a Survey of Residential Home Heating Fuel and Stove Type and Use in the Shiprock Area of the Navajo Nation

USGS Publications Warehouse

Bunnell, Joseph E.; Garcia, Linda V.

2008-01-01

For many Navajo people, coal provides an affordable and convenient means of home heating. However, coal combustion results in the formation and mobilization of materials that are known risk factors for respiratory and other diseases. The level of respiratory morbidity among the Navajo people is higher than can be explained by usual epidemiological risk factors. The Shiprock area of the Navajo Nation is somewhat unique in that atmospheric thermal inversions trap air pollution low to the ground, especially in winter. There are two large mine mouth coal-fired power plants located in the vicinity, with a third plant in the planning stages. Both of the existing power plants are exempt from regulation under the U.S. Environmental Protection Agency 1990 Amendments to the Clean Air Act due to their age. The purpose of this survey was to assess the fuel and stove type and use, and document other household characteristics that might be related to the exposure of potentially toxic coal combustion products. A total of 137 surveys was conducted in English and Navajo to ascertain and document fuel usage and the type, size and conditions of heating stoves used in both traditional and modern homes. Results have been presented to the community at the Shiprock Chapter in the Navajo language. To increase public awareness, ways to properly use and store coal and to improve stove function and ventilation were also shared.

WISC-R Factor Structures for Diagnosed Learning Disabled Navajo and Papago Children.

ERIC Educational Resources Information Center

Zarske, John A.; And Others

1981-01-01

Wechsler Intelligence Scale for Children (Revised) (WISC-R) factor structures were compared for learning disabled Navajo and Papago children. Results support the validity of the WISC-R as a measure of general intellectual functioning, and verbal and performance aspects for both groups, indicating its appropriateness for diverse groups of children.…

A perfect flower from the Jurassic of China

PubMed Central

Liu, Zhong-Jian; Wang, Xin

2016-01-01

Flower, enclosed ovule and tetrasporangiate anther are three major characters distinguishing angiosperms from other seed plants. Morphologically, typical flowers are characterised by an organisation with gynoecium and androecium surrounded by corolla and calyx. Theoretically, flowers are derived from their counterparts in ancient ancestral gymnosperms. However, as for when, how and from which groups, there is no consensus among botanists yet. Although angiosperm-like pollen and angiosperms have been claimed in the Triassic and Jurassic, typical flowers with the aforesaid three key characters are still missing in the pre-Cretaceous age, making many interpretations of flower evolution tentative. Thus searching for flower in the pre-Cretaceous has been a tantalising task for palaeobotanists for a long time. Here, we report a typical flower, Euanthus panii gen. et sp. nov., from the Middle–Late Jurassic of Liaoning, China. Euanthus has sepals, petals, androecium with tetrasporangiate dithecate anthers and gynoecium with enclosed ovules, organised just like in perfect flowers of extant angiosperms. The discovery of Euanthus implies that typical angiosperm flowers have already been in place in the Jurassic, and provides a new insight unavailable otherwise for the evolution of flowers. PMID:27134345

A perfect flower from the Jurassic of China.

PubMed

Liu, Zhong-Jian; Wang, Xin

2016-07-03

Flower, enclosed ovule and tetrasporangiate anther are three major characters distinguishing angiosperms from other seed plants. Morphologically, typical flowers are characterised by an organisation with gynoecium and androecium surrounded by corolla and calyx. Theoretically, flowers are derived from their counterparts in ancient ancestral gymnosperms. However, as for when, how and from which groups, there is no consensus among botanists yet. Although angiosperm-like pollen and angiosperms have been claimed in the Triassic and Jurassic, typical flowers with the aforesaid three key characters are still missing in the pre-Cretaceous age, making many interpretations of flower evolution tentative. Thus searching for flower in the pre-Cretaceous has been a tantalising task for palaeobotanists for a long time. Here, we report a typical flower, Euanthus panii gen. et sp. nov. , from the Middle-Late Jurassic of Liaoning, China. Euanthus has sepals, petals, androecium with tetrasporangiate dithecate anthers and gynoecium with enclosed ovules, organised just like in perfect flowers of extant angiosperms. The discovery of Euanthus implies that typical angiosperm flowers have already been in place in the Jurassic, and provides a new insight unavailable otherwise for the evolution of flowers.

The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

PubMed Central

Danise, Silvia; Twitchett, Richard J.; Little, Crispin T. S.; Clémence, Marie-Emilie

2013-01-01

The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans. PMID:23457537

The impact of global warming and anoxia on marine benthic community dynamics: an example from the Toarcian (Early Jurassic).

PubMed

Danise, Silvia; Twitchett, Richard J; Little, Crispin T S; Clémence, Marie-Emilie

2013-01-01

The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of "dead zones" in modern oceans.

Megalosauripus transjuranicus ichnosp. nov. A new Late Jurassic theropod ichnotaxon from NW Switzerland and implications for tridactyl dinosaur ichnology and ichnotaxomy.

PubMed

Razzolini, Novella L; Belvedere, Matteo; Marty, Daniel; Paratte, Géraldine; Lovis, Christel; Cattin, Marielle; Meyer, Christian A

2017-01-01

A new ichnospecies of a large theropod dinosaur, Megalosauripus transjuranicus, is described from the Reuchenette Formation (Early-Late Kimmeridgian, Late Jurassic) of NW Switzerland. It is based on very well-preserved and morphologically-distinct tracks (impressions) and several trackways, including different preservational types from different tracksites and horizons. All trackways were excavated along federal Highway A16 near Courtedoux (Canton Jura) and systematically documented in the field including orthophotos and laserscans. The best-preserved tracks were recovered and additional tracks were casted. Megalosauripus transjuranicus is characterized by tridactyl tracks with clear claw and digital pad impressions, and notably an exceptionally large and round first phalangeal pad on the fourth digit (PIV1) that is connected to digit IV and forms the round heel area. Due to this combination of features, M. transjuranicus clearly is of theropod (and not ornithopod) origin. M. transjuranicus is compared to other Megalosauripus tracks and similar ichnotaxa and other unassigned tracks from the Early Jurassic to Early Cretaceous. It is clearly different from other ichnogenera assigned to large theropods such as Eubrontes-Grallator from the Late Triassic and Early Jurassic or Megalosauripus-Megalosauropus-Bueckeburgichnus and Therangospodus tracks from the Late Jurassic and Early Cretaceous. A second tridactyl morphotype (called Morphotype II) is different from Megalosauripus transjuranicus in being subsymmetric, longer than wide (sometimes almost as wide as long), with blunt toe impressions and no evidence for discrete phalangeal pad and claw marks. Some Morphotype II tracks are found in trackways that are assigned to M. transjuranicus, to M.? transjuranicus or M. cf. transjuranicus indicating that some Morphotype II tracks are intra-trackway preservational variants of a morphological continuum of Megalosauripus transjuranicus. On the other hand, several up to 40 steps

Breccia pipes in the Karoo Basin, South Africa, as conduits for metamorphic gases to the Early Jurassic atmosphere

NASA Astrophysics Data System (ADS)

Silkoset, Petter; Svensen, Henrik; Planke, Sverre

2014-05-01

The Toarcian (Early Jurassic) event was manifested by globally elevated temperatures and anoxic ocean conditions that particularly affected shallow marine taxa. The event coincided with the emplacement of the vast Karoo-Ferrar Large Igneous Province. Among the suggestions for trigger mechanisms for the climatic perturbation is metamorphic methane generation from black shale around the sills in the Karoo Basin, South Africa. The sill emplacement provides a mechanism for voluminous in-situ production and emission of greenhouse gases, and establishes a distinct link between basin-trapped and atmospheric carbon. In the lower stratigraphic levels of the Karoo Basin, black shales are metamorphosed around sills and the sediments are cut by a large number of pipe structures with metamorphic haloes. The pipes are vertical, cylindrical structures that contain brecciated and baked sediments with variable input of magmatic material. Here, we present borehole, petrographic, geochemical and field data from breccia pipes and contact aureoles based on field campaigns over a number of years (2004-2014). The metamorphism around the pipes show equivalent metamorphic grade as the sediments around nearby sills, suggesting a more prominent phreatomagmatic component than previously thought. The stratigraphic position of pipes and the breccia characteristics strengthens the hypothesis of a key role in the Toarcian carbon isotope excursion.

Recycling of Amazonian detrital zircons in the Mixteco terrane, southern Mexico: Paleogeographic implications during Jurassic-Early Cretaceous and Paleogene times

NASA Astrophysics Data System (ADS)

Silva-Romo, Gilberto; Mendoza-Rosales, Claudia Cristina; Campos-Madrigal, Emiliano; Morales-Yáñez, Axél; de la Torre-González, Alam Israel; Nápoles-Valenzuela, Juan Ivan

2018-04-01

In the northeastern Mixteco terrane of southern Mexico, in the Ixcaquixtla-Atzumba region, the recycling of Amazonian detrital zircons records the paleogeography during the Mesozoic period in the context of the breakup of Pangea, a phenomenon that disarticulated the Sanozama-La Mora paleo-river. The clastic units of southern Mexico in the Ayuquila, Otlaltepec and Zapotitlán Mesozoic basins, as well as in the Atzumba Cenozoic basin, are characterized by detrital zircon contents with ages specific to the Amazonian craton, ranging between 3040 and 1278 Ma. The presence of zircons of Amazonian affinity suggests a provenance by recycling from carrier units such as the La Mora Formation or the Ayú Complex. In the area, the Ayú and Acatlán complexes form the Cosoltepec block, a paleogeographic element that during Early Cretaceous time acted as the divide between the slopes of the paleo-Gulf of Mexico and the paleo-Pacific Ocean. The sedimentological characteristics of the Jurassic-Cenozoic clastic successions in the Ixcaquixtla-Atzumba region denote relatively short transport in braided fluvial systems and alluvial fans. In this way, several basins are recognized around the Cosoltepec block. At the southeastern edge of the Cosoltepec block, the Ayuquila and Tecomazúchil formations accumulated in the Ayuquila continental basin on the paleo-Pacific Ocean slope. On the other hand, within the paleo-Gulf of Mexico slope, in the Otlaltepec continental basin, the Piedra Hueca and the Otlaltepec formations accumulated. The upper member of the Santa Lucía Formation accumulated in a transitional environment on the southwestern shoulder of the Zapotitlán basin, as well as on the paleo-Gulf of Mexico slope. In the Ayuquila basin, a marine transgression is recognized that advanced from south to north during the Late Jurassic. At the northeastern edge of the Cosoltepec block, we propose that the Santa Lucía formation attests to a transgression from the paleo-Gulf of Mexico

Geothermal regime and Jurassic source rock maturity of the Junggar basin, northwest China

NASA Astrophysics Data System (ADS)

Nansheng, Qiu; Zhihuan, Zhang; Ershe, Xu

2008-01-01

source rocks of the Central Depression and Southern Depression increases with depth. The source rocks only reached an early maturity with a R0 of 0.5-0.7% in the Wulungu Depression, the Luliang Uplift and the Western Uplift, whereas they did not enter the maturity window ( R0 < 0.5%) in the Eastern Uplift of the basin. This maturity evolution will provide information of source kitchen for the Jurassic exploration.

Adaptations for marine habitat and the effect of Triassic and Jurassic predator pressure on development of decompression syndrome in ichthyosaurs

NASA Astrophysics Data System (ADS)

Rothschild, B. M.; Xiaoting, Z.; Martin, L. D.

2012-06-01

Decompression syndrome (caisson disease or the "the bends") resulting in avascular necrosis has been documented in mosasaurs, sauropterygians, ichthyosaurs, and turtles from the Middle Jurassic to Late Cretaceous, but it was unclear that this disease occurred as far back as the Triassic. We have examined a large Triassic sample of ichthyosaurs and compared it with an equally large post-Triassic sample. Avascular necrosis was observed in over 15 % of Late Middle Jurassic to Cretaceous ichthyosaurs with the highest occurrence (18 %) in the Early Cretaceous, but was rare or absent in geologically older specimens. Triassic reptiles that dive were either physiologically protected, or rapid changes of their position in the water column rare and insignificant enough to prevent being recorded in the skeleton. Emergency surfacing due to a threat from an underwater predator may be the most important cause of avascular necrosis for air-breathing divers, with relative frequency of such events documented in the skeleton. Diving in the Triassic appears to have been a "leisurely" behavior until the evolution of large predators in the Late Jurassic that forced sudden depth alterations contributed to a higher occurrence of bends.

Adaptations for marine habitat and the effect of Triassic and Jurassic predator pressure on development of decompression syndrome in ichthyosaurs.

PubMed

Rothschild, B M; Xiaoting, Z; Martin, L D

2012-06-01

Decompression syndrome (caisson disease or the "the bends") resulting in avascular necrosis has been documented in mosasaurs, sauropterygians, ichthyosaurs, and turtles from the Middle Jurassic to Late Cretaceous, but it was unclear that this disease occurred as far back as the Triassic. We have examined a large Triassic sample of ichthyosaurs and compared it with an equally large post-Triassic sample. Avascular necrosis was observed in over 15% of Late Middle Jurassic to Cretaceous ichthyosaurs with the highest occurrence (18%) in the Early Cretaceous, but was rare or absent in geologically older specimens. Triassic reptiles that dive were either physiologically protected, or rapid changes of their position in the water column rare and insignificant enough to prevent being recorded in the skeleton. Emergency surfacing due to a threat from an underwater predator may be the most important cause of avascular necrosis for air-breathing divers, with relative frequency of such events documented in the skeleton. Diving in the Triassic appears to have been a "leisurely" behavior until the evolution of large predators in the Late Jurassic that forced sudden depth alterations contributed to a higher occurrence of bends.

Jurassic through Oligocene paleogeography of the Santa Maria basin area, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fritsche, A.E.; Yamashiro, D.A.

1991-02-01

Compilation from published reports indicates that the paleogeographic history of the Santa Maria basin area of California (west of the Sur-Nacimiento fault and north of the Santa Ynez Fault) began in the Early Jurassic in an area for to the south with the creation of a spreading-center ophiolite sequence. As the ophiolite rocks moved relatively away from the spreading center, they were covered by Lower Jurassic through Lower Cretaceous basin plain and prograding outer continental margin deposits. During this time, right-lateral movement along faults that were located to the east was transporting the area relatively northward toward its present location.more » A mild tectonic event in the middle of the Cretaceous caused formation of a parallel unconformity. Renewed subsidence in the Late Cretaceous brought deposition in trench, slope, sandy submarine fan, shelf, and ultimately in the eastern part of the area, delta and fluvial environments. During the ensuing Laramide orogeny, significant deformation raised the entire area above sea level and erosion created a major angular unconformity. During the early Tertiary, most of the Santa Maria basin area remained elevated as a forearc highland. The present-day east-west-trending area south of the Santa Ynez River fault was at the time oriented north-south. During the Eocene, this portion of the area was submerged and became a forearc basin that was located to the east of the forearc ridge that served as a source of sediment. The basin filled through the Eocene and Oligocene with submarine fan, sloe, shelf, coastal, and finally fluvial deposits. In the medial Miocene, these forearc basin rocks were rotated clockwise into their present position along the southern margin of the basin and the upper Tertiary Santa maria basin was formed.« less

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,…

A Cluster-Randomized, Community-Based, Tribally Delivered Oral Health Promotion Trial in Navajo Head Start Children.

PubMed

Braun, P A; Quissell, D O; Henderson, W G; Bryant, L L; Gregorich, S E; George, C; Toledo, N; Cudeii, D; Smith, V; Johs, N; Cheng, J; Rasmussen, M; Cheng, N F; Santo, W; Batliner, T; Wilson, A; Brega, A; Roan, R; Lind, K; Tiwari, T; Shain, S; Schaffer, G; Harper, M; Manson, S M; Albino, J

2016-10-01

The authors tested the effectiveness of a community-based, tribally delivered oral health promotion (OHP) intervention (INT) at reducing caries increment in Navajo children attending Head Start. In a 3-y cluster-randomized trial, we developed an OHP INT with Navajo input that was delivered by trained Navajo lay health workers to children attending 52 Navajo Head Start classrooms (26 INT, 26 usual care [UC]). The INT was designed as a highly personalized set of oral health-focused interactions (5 for children and 4 for parents), along with 4 fluoride varnish applications delivered in Head Start during academic years of 2011 to 2012 and 2012 to 2013. The authors evaluated INT impact on decayed, missing, and filled tooth surfaces (dmfs) increment compared with UC. Other outcomes included caries prevalence and caregiver oral health-related knowledge and behaviors. Modified intention-to-treat and per-protocol analyses were conducted. The authors enrolled 1,016 caregiver-child dyads. Baseline mean dmfs/caries prevalence equaled 19.9/86.5% for the INT group and 22.8/90.1% for the UC group, respectively. INT adherence was 53% (i.e., ≥3 child OHP events, ≥1 caregiver OHP events, and ≥3 fluoride varnish). After 3 y, dmfs increased in both groups (+12.9 INT vs. +10.8 UC; P = 0.216), as did caries prevalence (86.5% to 96.6% INT vs. 90.1% to 98.2% UC; P = 0.808) in a modified intention-to-treat analysis of 897 caregiver-child dyads receiving 1 y of INT. Caregiver oral health knowledge scores improved in both groups (75.1% to 81.2% INT vs. 73.6% to 79.5% UC; P = 0.369). Caregiver oral health behavior scores improved more rapidly in the INT group versus the UC group (P = 0.006). The dmfs increment was smaller among adherent INT children (+8.9) than among UC children (+10.8; P = 0.028) in a per-protocol analysis. In conclusion, the severity of dental disease in Navajo Head Start children is extreme and difficult to improve. The authors argue that successful approaches to

Sedimentary Provenance Constraints on the Middle Jurassic to Late Cretaceous Paleogeography of the Sichuan Basin, SW China

NASA Astrophysics Data System (ADS)

Li, Y.; He, D.; Li, D.; Lu, R.

2017-12-01

Sedimentary provenance of the Middle Jurassic to Late Cretaceous sediments in the Sichuan Basin is constrained by sandstone petrology and detrital zircon U-Pb geochronology, which provides critical insights into mid-late Mesozoic paleogeographic evolution of the Sichuan Basin. Petrographic analyses of 22 sandstone samples indicate moderate to high mature sediments and are primarily derived from cratonic or recycled sources. U-Pb age data for the Middle Jurassic to Late Cretaceous detrital zircons generally show populations at 130-200, 200-330, 400-490, 680-890, 1730-1960, and 2360-2600 Ma, with up-section variations. The Middle Jurassic sediments contain a relatively high density of 1.85 and 2.5 Ga zircons and a low density of the 800 Ma zircons, which are consistent with derivation mainly from the Songpan-Ganzi terrane and the South Qinling belt, and secondarily from the Western Jiangnan Orogen. The Late Jurassic and Early Cretaceous sedimentation with a scattered age distribution shared common multiple-source to sink systems that were predominantly draining towards the south and southeast, but increasingly drained southward, and were later disrupted by a synchronous northeastward drainage capture. Late Cretaceous sediments have a distinct reduction in <213 Ma zircons, suggesting that sedimentation involved southeastward and southwestward transport of sediments likely derived from the Songpan-Ganzi terrane, the south segment of the Longmenshan fault belt and western Yangtze Craton, and the uplifting areas of the N- and NE-Sichuan Basin. Changes in provenances during the mid-late Mesozoic period are coincident with temporal-spatial variations in depocenter migration and paleogeographic evolution of the Sichuan Basin, which are closely related to the multi-stage intracontinental subduction associated with clockwise rotation of the South China Block.

Strengthening the role of Community Health Representatives in the Navajo Nation.

PubMed

King, Caroline; Goldman, Alex; Gampa, Vikas; Smith, Casey; Muskett, Olivia; Brown, Christian; Malone, Jamy; Sehn, Hannah; Curley, Cameron; Begay, Mae-Gilene; Nelson, Adrianne Katrina; Shin, Sonya Sunhi

2017-04-21

Strengthening Community Health Worker systems has been recognized to improve access to chronic disease prevention and management efforts in low-resource communities. The Community Outreach and Patient Empowerment (COPE) Program is a Native non-profit organization with formal partnerships with both the Navajo Nation Community Health Representative (CHR) Program and the clinical facilities serving the Navajo Nation. COPE works to better integrate CHRs into the local health care system through training, strengthening care coordination, and a standardized culturally appropriate suite of health promotion materials for CHRs to deliver to high-risk individuals in their homes. The objective of this mixed methods, cross sectional evaluation of a longitudinal cohort study was to explore how the COPE Program has effected CHR teams over the past 6 years. COPE staff surveyed CHRs in concurrent years (2014 and 2015) about their perceptions of and experience working with COPE, including potential effects COPE may have had on communication among patients, CHRs, and hospital-based providers. COPE staff also conducted focus groups with all eight Navajo Nation CHR teams. CHRs and other stakeholders who viewed our results agree that COPE has improved clinic-community linkages, primarily through strengthened collaborations between Public Health Nurses and CHRs, and access to the Electronic Health Records. CHRs perceived that COPE’s programmatic support has strengthened their validity and reputation with providers and clients, and has enhanced their ability to positively effect health outcomes among their clients. CHRs report an improved ability to deliver health coaching to their clients. Survey results show that 80. 2% of CHRs feel strongly positive that COPE trainings are useful, while 44.6% of CHRs felt that communication and teamwork had improved because of COPE. These findings suggest that CHRs have experienced positive benefits from COPE through training. COPE may provide a

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…

Finding of two new radiolarian associations calibrated with ammonoids in the Vaca Muerta Formation (Late Jurassic-Early Cretaceous), Neuquén Basin, Argentina

NASA Astrophysics Data System (ADS)

Vennari, Verónica V.; Pujana, Ignacio

2017-04-01

An association of ammonoids and radiolarians retrieved from a sedimentary section of the Vaca Muerta Formation at Vega de Escalone, Neuquén Basin, Argentina, was analized under a strict stratigraphic control. Nine ammonoid assemblage biozones were identified, indicating an age span from Early Tithonian to Late Berriasian/earlymost Valanginian for the Vaca Muerta Formation at the studied section. In connection to the ammonoid record, two radiolarian faunas were identified and named J3A1 and J3B1. Fauna J3A1, corresponding to the Virgatosphinctes andesensis Biozone, is dominated by nasellarian genera and represents the first Lower Tithonian radiolarian fauna described from the Neuquén Basin. Fauna J3B1, linked to the interval assigned to the Substeueroceras koeneni Biozone (Late Tithonian-Early Berriasian), yields abundant representatives of the Pantanellid Family. The presence of Complexapora kozuri (Kiessling and Zeiss) and Loopus primitivus (Matsuoka and Yao), two important radiolarian primary markers of the Late Jurassic in North America, supports a Late Tithonian age for at least part of the S. koeneni Biozone in the studied area. Nor certain Berriasian radiolarian faunas nor elements of the Vallupinae Family were identified so far at the Vega de Escalone section.

Major strike-slip faulting along the tectonic boundary between East and West Antarctica: implications for early Gondwana break-up and Jurassic granitic magma emplacement

NASA Astrophysics Data System (ADS)

Jordan, T. A.; Ferraccioli, F.; Anderson, L.; Ross, N.; Corr, H.; Leat, P. T.; Bingham, R.; Rippin, D. M.; Le Brocq, A. M.; Siegert, M. J.

2013-12-01

The fragmentation of the Gondwana supercontinent began with continental rifting between the Weddell Sea region of Antarctica and South Africa during the Jurassic. This initial Jurassic phase of continental rifting is critical for understanding the process that initiated supercontinent breakup and dispersal, including the role of mantle plumes and major intracrustal tectonic structures. However, due to the remote location and blanketing ice sheets, the tectonic and magmatic evolution of the Weddell Sea Sector of Antarctica has remained relatively poorly understood. Our recent aeromagnetic and airborne gravity investigations have revealed the inland extent of the Weddell Sea Rift system beneath the West Antarctic Ice Sheet, and indicate the presence of a major left-lateral strike slip fault system separating the Ellsworth Whitmore block (a possible exotic microcontinent derived from the Natal Embayment, or the Shackleton Range region of East Antarctica) from East Antarctica (Jordan et al., 2013 Tectonophysics). In this study we use GPlates plate-tectonic reconstruction software to start evaluating the influence of strike-slip faulting between East and West Antarctica on Gondwana breakup models. Specifically, we investigate the possibility of poly-phase motion along the fault system and explore scenarios involving more diffuse strike slip faulting extending into the interior of East Antarctica in the hinterland of the Transantarctic Mountains. Our preliminary models suggest that there may be a link between the prominent step in the flank of the later Cretaceous-Cenozoic West Antarctic Rift System (at the southern end of Ellsworth-Whitmore Block) and the earlier Jurassic Weddell Sea rift system. Additionally, we present preliminary joint 3D magnetic and gravity models to investigate the crustal architecture of the proposed strike-slip fault system and assess its influence on the emplacement of voluminous Jurassic granitic magmatism along the boundary of the Ellsworth

Anomalous Late Jurassic motion of the Pacific Plate with implications for true polar wander

NASA Astrophysics Data System (ADS)

Fu, Roger R.; Kent, Dennis V.

2018-05-01

True polar wander, or TPW, is the rotation of the entire mantle-crust system about an equatorial axis that results in a coherent velocity contribution for all lithospheric plates. One of the most recent candidate TPW events consists of a ∼30° rotation during Late Jurassic time (160-145 Ma). However, existing paleomagnetic documentation of this event derives exclusively from continents, which compose less than 50% of the Earth's surface area and may not reflect motion of the entire mantle-crust system. Additional paleopositional information from the Pacific Basin would significantly enhance coverage of the Earth's surface and allow more rigorous testing for the occurrence of TPW. We perform paleomagnetic analyses on core samples from Ocean Drilling Program (ODP) Site 801B, which were taken from the oldest available Pacific crust, to determine its paleolatitude during the Late Jurassic and Early Cretaceous (167-133 Ma). We find that the Pacific Plate underwent a steady southward drift of 0.49°-0.74° My-1 except for an interval between Kimmeridgian and Tithonian time (157-147 Ma), during which it underwent northward motion at 1.45° ± 0.76° My-1 (1σ). This trajectory indicates that the plates of the Pacific Basin participated in the same large-amplitude (∼30°) rotation as continental lithosphere in the 160-145 Ma interval. Such coherent motion of a large majority of the Earth's surface strongly supports the occurrence of TPW, suggesting that a combination of subducting slabs and rising mantle plumes was sufficient to significantly perturb the Earth's inertia tensor in the Late Jurassic.

Geochemical characterization of the Jurassic Amran deposits from Sharab area (SW Yemen): Origin of organic matter, paleoenvironmental and paleoclimate conditions during deposition

NASA Astrophysics Data System (ADS)

Hakimi, Mohammed Hail; Abdullah, Wan Hasiah; Makeen, Yousif M.; Saeed, Shadi A.; Al-Hakame, Hitham; Al-Moliki, Tareq; Al-Sharabi, Kholah Qaid; Hatem, Baleid Ali

2017-05-01

is attributed to the thermal effect on the original organic matter. This high thermal maturity level is due to the presence of volcanic rocks, which have invaded the Jurassic rocks during Late Oligocene to Early Miocene.

Plume type ophiolites in Japan, East Russia and Mongolia: Peculiarity of the Late Jurassic examples

NASA Astrophysics Data System (ADS)

Ishiwatari, Akira; Ichiyama, Yuji; Ganbat, Erdenesaikhan

2013-04-01

Dilek and Furnes (2011; GSAB) provided a new comprehensive classification of ophiolites. In addition to the mid-ocean ridge (MOR) and supra-subduction zone (SSZ) types that are known for decades, they introduced rift-zone (passive margin) type, volcanic arc (active margin) type, and plume type. The last type is thought to be originated in oceanic large igneous provinces (LIPs; oceanic plateaus), and is preserved in the subduction-accretion complexes in the Pacific margins. The LIP-origin greenstones occur in the Middle Paleozoic (Devonian) accretionary complex (AC) in central Mongolia (Ganbat et al. 2012; AGU abst.). The Late Paleozoic and Mesozoic plume-type ophiolites are abundant in Japan. They are Carboniferous greenstones covered by thick limestone in the Akiyoshi belt (Permian AC, SW Japan; Tatsumi et al., 2000; Geology), Permian greenstones in the Mino-Tamba belt (Jurassic AC, SW Japan; Ichiyama et al. 2008; Lithos), and Late Jurassic-Early Cretaceous greenstone in the Sorachi (Hokkaido; Ichiyama et al, 2012; Geology) and Mikabu (SW Japan; this study) belts. The LIP origin of these greenstones is indicated by abundance of picrite (partly komatiite and meimechite), geochemical features resembling HIMU basalts (e.g. high Nb/Y and Zr/Y) and Mg-rich (up to Fo93) picritic olivines following the "mantle array", suggesting very high (>1600oC) temperature of the source mantle plume. The Sorachi-Mikabu greenstones are characterized by the shorter time interval between magmatism and accretion than the previous ones, and are coeval with the meimechite lavas and Alaskan-type ultramafic intrusions in the Jurassic AC in Sikhote-Alin Mountains of Primorye (E. Russia), that suggest a superplume activity in the subduction zone (Ishiwatari and Ichiyama, 2004; IGR). The Mikabu greenstones extend for 800 km along the Pacific coast of SW Japan, and are characterized by the fragmented "olistostrome" occurrence of the basalts, gabbros and ultramafic cumulate rocks (but no mantle

Early to middle Jurassic salt in Baltimore Canyon trough

USGS Publications Warehouse

McKinney, B. Ann; Lee, Myung W.; Agena, Warren F.; Poag, C. Wylie

2005-01-01

A pervasive, moderately deep (5-6 s two-way traveltime), high-amplitude reflection is traced on multichannel seismic sections over an approximately 7500 km² area of Baltimore Canyon Trough. The layer associated with the reflection is about 25 km wide, about 60 m thick in the center, and thins monotonically laterally, though asymmetrically, at the edges. Geophysical characteristics are compatible with an interpretation of this negative-polarity reflector as a salt lens deposited on the top of a synrift evaporite sequence. However, alternative interpretations of the layer as gas-saturated sediments, an overpressured shale, or a weathered igneous intrusion are also worthy of consideration.Geophysical analyses were made on three wavelet- and true-amplitude processed multichannel seismic dip lines. The lens-shaped layer demarked by the reflection has a velocity of 4.4 km/s; the lens lies within strata having velocities of 5.3 to 5.7 km/s. A trough marking the onset of the lens has an amplitude that is 10 to 20 db greater than reflections from the encasing layers and an apparent reflection coefficient of -0.24. Using amplitude versus offset analysis methods, we determined that observed reflection coefficients, though variable, decrease consistently with respect to increasing offset. Linear inversion yields a low density, about 2.2 g/cc. Integration of one of the true-amplitude-processed lines and one-dimensional modeling of the layer provide data on the impedance contrast and interference patterns that further reinforce the salt lens interpretation.The thin, horizontal salt lens was probably deposited or precipitated during the Jurassic in a shallow, narrow (peripheral) rift basin, as rifting progressed down the North Atlantic margin. Unlike thicker deposits in other areas that deformed and flowed, often into diapir structures, this thin lens has remained relatively undisturbed since deposition.

Evolution of the carbon cycle and seawater temperature from the Triassic-Jurassic boundary to the Early Toarcian based on brachiopod geochemistry

NASA Astrophysics Data System (ADS)

Müller, Tamás; Tomašových, Adam

2017-04-01

The ecological crisis and extinction at the end of the Triassic coincides with several environmental perturbations such as global temperature rise, ocean acidification and carbon isotope anomalies, with a large observed negative carbon isotope excursion (CIE) in the Late Rhaetian as well. Followed by the ETE, the Early Jurassic was characterized by marked fluctuations of the global seawater temperature and carbon cycle. Carbon isotope records are showing positive and remarkable negative excursions. A particular example of these phenomena is connected to the Toarcian Oceanic Anoxic Event (TOAE). The δ13C record of the TOAE is showing a negative excursion of a high magnitude, suggesting the injection of large amount of light carbon into the ocean-atmosphere system, coinciding with rapid global warming and widespread anoxia. Beside the TOAE there are many other, smaller scale carbon isotope anomalies and environmental perturbations at the Sinemurian-Pliensbachian transition or at the Pliensbachian-Toarcian boundary. In our study, we provide new brachiopod δ13C, δ18O, and Mg/Ca data from the time interval starting in the Rhaetian till the end of the Early Toarcian. Considering the strong resistance of brachiopod shells against diagenesis, our aim is to reconstruct seawater temperature, seawater Mg/Ca, and carbon cycle evolution based on a reliable geochemical proxy database of the studied time interval. The samples have been collected from various localities across Europe achieving a good, at least ammonite subzone scale resolution for the Rhaetian stage and for the Lower Jurassic. The geochemical preservation of the shell material have been tested by several approaches. Thin-sections were made from the shells and analyzed by electron microprobe and ICP-OES to evaluate their preservation by assessing concentrations of Fe, Mn, Sr, and their ratios (Mn/Ca, Sr/Ca). Considering the various elemental composition data of fossil and recent brachiopods published by several

Detrital zircon microtextures and U-PB geochronology of Upper Jurassic to Paleocene strata in the distal North American Cordillera foreland basin

NASA Astrophysics Data System (ADS)

Finzel, E. S.

2017-07-01

Detrital zircon surface microtextures, geochronologic U-Pb data, and tectonic subsidence analysis from Upper Jurassic to Paleocene strata in the Black Hills of South Dakota reveal provenance variations in the distal portion of the Cordillera foreland basin in response to tectonic events along the outboard margin of western North America. During Late Jurassic to Early Cretaceous time, nonmarine strata record initially low rates of tectonic subsidence that facilitated widespread recycling of older foreland basin strata in eolian and fluvial systems that dispersed sediment to the northeast, with minimal sediment derived from the thrust belt. By middle Cretaceous time, marine inundation reflects increased subsidence rates coincident with a change to eastern sediment sources. Lowstand Albian fluvial systems in the Black Hills may have been linked to fluvial systems upstream in the midcontinent and downstream in the Bighorn Basin in Wyoming. During latest Cretaceous time, tectonic uplift in the study area reflects dynamic processes related to Laramide low-angle subduction that, relative to other basins to the west, was more influential due to the greater distance from the thrust load. Provenance data from Maastrichtian and lower Paleocene strata indicate a change back to western sources that included the Idaho-Montana batholith and exhumed Belt Supergroup. This study provides a significant contribution to the growing database that is refining the tectonics and continental-scale sediment dispersal patterns in North America during Late Jurassic-early Paleocene time. In addition, it demonstrates the merit of using detrital zircon grain shape and surface microtextures to aid in provenance interpretations.

The Early Mesozoic volcanic arc of western North America in northeastern Mexico

NASA Astrophysics Data System (ADS)

Barboza-Gudiño, José Rafael; Orozco-Esquivel, María Teresa; Gómez-Anguiano, Martín; Zavala-Monsiváis, Aurora

2008-02-01

Volcanic successions underlying clastic and carbonate marine rocks of the Oxfordian-Kimmeridgian Zuloaga Group in northeastern Mexico have been attributed to magmatic arcs of Permo-Triassic and Early Jurassic ages. This work provides stratigraphic, petrographic geochronological, and geochemical data to characterize pre-Oxfordian volcanic rocks outcropping in seven localities in northeastern Mexico. Field observations show that the volcanic units overlie Paleozoic metamorphic rocks (Granjeno schist) or Triassic marine strata (Zacatecas Formation) and intrude Triassic redbeds or are partly interbedded with Lower Jurassic redbeds (Huizachal Group). The volcanic rocks include rhyolitic and rhyodacitic domes and dikes, basaltic to andesitic lava flows and breccias, and andesitic to rhyolitic pyroclastic rocks, including breccias, lapilli, and ashflow tuffs that range from welded to unwelded. Lower-Middle Jurassic ages (U/Pb in zircon) have been reported from only two studied localities (Huizachal Valley, Sierra de Catorce), and other reported ages (Ar/Ar and K-Ar in whole-rock or feldspar) are often reset. This work reports a new U/Pb age in zircon that confirms a Lower Jurassic (193 Ma) age for volcanic rocks exposed in the Aramberri area. The major and trace element contents of samples from the seven localities are typical of calc-alkaline, subduction-related rocks. The new geochronological and geochemical data, coupled with the lithological features and stratigraphic positions, indicate volcanic rocks are part of a continental arc, similar to that represented by the Lower-Middle Jurassic Nazas Formation of Durango and northern Zacatecas. On that basis, the studied volcanic sequences are assigned to the Early Jurassic volcanic arc of western North America.

Petrogenesis of Jurassic granitoids at the northeastern margin of the North China Craton: New geochemical and geochronological constraints on subduction of the Paleo-Pacific Plate

NASA Astrophysics Data System (ADS)

Liu, Jin; Zhang, Jian; Liu, Zhenghong; Yin, Changqing; Zhao, Chen; Peng, Youbo

2018-06-01

At the junction between the North China Craton (NCC) and the Central Asian Orogenic Belt (CAOB), northern Liaoning province, NE China, there are widespread Jurassic igneous rocks. The tectonic setting and petrogenesis of these rocks are unresolved. Zircon U-Pb dating, whole-rock geochemistry, and Hf isotopic compositions of Jurassic granitoids were investigated to constrain their ages and petrogenesis in order to understand the tectonic evolution of the Paleo-Pacific Ocean along the northeastern margin of the NCC. Geochronological data indicate that magmatism occurred between the early and late Jurassic (180-156 Ma). Despite the wide range in ages of the intrusions, Jurassic granitoids were likely derived from a similar or common source, as inferred from their geochemical and Hf isotopic characteristics. Compared to the island arc andesite-dacite-rhyolite series, the Jurassic granitoids are characterized by higher SiO2, Al2O3, and Sr contents, and lower MgO, FeOT, Y, and Yb contents, indicating that the primary magmas show typical characteristics of adakitic magmas derived from partial melting of thickened lower crust. These findings, combined with their εHf(t) values (+1.4 to +5.4) and two-stage model ages (1515-1165 Ma), indicate the primary magmas originated from partial melting of juvenile crustal material accreted during the Mesoproterozoic. They are enriched in large-ion lithophile elements (e.g., Rb, K, Th, Ba, and U) and light rare-earth elements (REE), and depleted in high-field-strength elements (e.g., Nb, Ta, Ti, and P) and heavy REE. Based on these findings and previous studies, we suggest that the Jurassic adakitic granitoids (180-156 Ma) were formed in an active continental margin and compressive tectonic setting, related to subduction of the Paleo-Pacific Plate.

Megalosauripus transjuranicus ichnosp. nov. A new Late Jurassic theropod ichnotaxon from NW Switzerland and implications for tridactyl dinosaur ichnology and ichnotaxomy

PubMed Central

Razzolini, Novella L.; Belvedere, Matteo; Marty, Daniel; Paratte, Géraldine; Lovis, Christel; Cattin, Marielle; Meyer, Christian A.

2017-01-01

A new ichnospecies of a large theropod dinosaur, Megalosauripus transjuranicus, is described from the Reuchenette Formation (Early–Late Kimmeridgian, Late Jurassic) of NW Switzerland. It is based on very well-preserved and morphologically-distinct tracks (impressions) and several trackways, including different preservational types from different tracksites and horizons. All trackways were excavated along federal Highway A16 near Courtedoux (Canton Jura) and systematically documented in the field including orthophotos and laserscans. The best-preserved tracks were recovered and additional tracks were casted. Megalosauripus transjuranicus is characterized by tridactyl tracks with clear claw and digital pad impressions, and notably an exceptionally large and round first phalangeal pad on the fourth digit (PIV1) that is connected to digit IV and forms the round heel area. Due to this combination of features, M. transjuranicus clearly is of theropod (and not ornithopod) origin. M. transjuranicus is compared to other Megalosauripus tracks and similar ichnotaxa and other unassigned tracks from the Early Jurassic to Early Cretaceous. It is clearly different from other ichnogenera assigned to large theropods such as Eubrontes–Grallator from the Late Triassic and Early Jurassic or Megalosauripus–Megalosauropus–Bueckeburgichnus and Therangospodus tracks from the Late Jurassic and Early Cretaceous. A second tridactyl morphotype (called Morphotype II) is different from Megalosauripus transjuranicus in being subsymmetric, longer than wide (sometimes almost as wide as long), with blunt toe impressions and no evidence for discrete phalangeal pad and claw marks. Some Morphotype II tracks are found in trackways that are assigned to M. transjuranicus, to M.? transjuranicus or M. cf. transjuranicus indicating that some Morphotype II tracks are intra-trackway preservational variants of a morphological continuum of Megalosauripus transjuranicus. On the other hand, several up to

Early diagenetic dolomitization and dedolomitization of Late Jurassic and earliest Cretaceous platform carbonates: A case study from the Jura Mountains (NW Switzerland, E France)

NASA Astrophysics Data System (ADS)

Rameil, Niels

2008-12-01

Early diagenetic dolomitization is a common feature in cyclic shallow-water carbonates throughout the geologic record. After their generation, dolomites may be subject to dedolomitization (re-calcification of dolomites), e.g. by contact with meteoric water during emersion. These patterns of dolomitization and subsequent dedolomitization frequently play a key role in unravelling the development and history of a carbonate platform. On the basis of excellent outcrops, detailed logging and sampling and integrating sedimentological work, high-resolution sequence stratigraphic interpretations, and isotope analyses (O, C), conceptual models on early diagenetic dolomitization and dedolomitization and their underlying mechanisms were developed for the Upper Jurassic / Lower Cretaceous Jura platform in north-western Switzerland and eastern France. Three different types of early diagenetic dolomites and two types of dedolomites were observed. Each is defined by a distinct petrographic/isotopic signature and a distinct spatial distribution pattern. Different types of dolomites are interpreted to have been formed by different mechanisms, such as shallow seepage reflux, evaporation on tidal flats, and microbially mediated selective dolomitization of burrows. Depending on the type of dolomite, sea water with normal marine to slightly enhanced salinities is proposed as dolomitizing fluid. Based on the data obtained, the main volume of dolomite was precipitated by a reflux mechanism that was switched on and off by high-frequency sea-level changes. It appears, however, that more than one dolomitization mechanism was active (pene)contemporaneously or several processes alternated in time. During early diagenesis, percolating meteoric waters obviously played an important role in the dedolomitization of carbonate rocks that underlie exposure surfaces. Cyclostratigraphic interpretation of the sedimentary succession allows for estimates on the timing of early diagenetic (de

Abandoned Uranium Mine (AUM) Surface Areas, Navajo Nation, 2016, US EPA Region 9

EPA Pesticide Factsheets

This GIS dataset contains polygon features that represent all Abandoned Uranium Mines (AUMs) on or within one mile of the Navajo Nation. Attributes include mine names, aliases, Potentially Responsible Parties, reclaimation status, EPA mine status, links to AUM reports, and the region in which an AUM is located. This dataset contains 608 features.

Educational Expectations in a Democratic Society Held by Navajo Parents and Their Children.

ERIC Educational Resources Information Center

Parent, Sydney B.; Bunderson, Eileen D.

Navajo students have a 31% dropout rate, and it has been getting worse. Although considerable research has examined the reasons behind this dropout rate, little attention has been given to parental expectations of their children's education. Interviews with 45 parents of students attending Montezuma Creek Elementary School, a public school on the…

Anomalous Late Jurassic motion of the Pacific Plate with implications for true polar wander

NASA Astrophysics Data System (ADS)

Fu, R. R.; Kent, D.

2017-12-01

True polar wander, or TPW, is the rotation of the entire mantle-crust system that results in simultaneous change in latitude and orientation for all lithospheric plates. One of the most recent candidate TPW events consists of a 30˚ rotation during Late Jurassic time (160 - 145 Ma). However, existing paleomagnetic documentation of this event derives exclusively from continental studies. Because all major landmasses except China were connected directly or via spreading centers in the Late Jurassic, the velocities of these continents were mutually constrained and their motion as a group over the underlying mantle would be indistinguishable from TPW using only continental data. On the other hand, plates of the Pacific Basin constituted a kinematically independent domain, interfacing with continents at subduction zones and slip-strike boundaries. Coherent motion of both Pacific Basin and continental plates would therefore indicate uniform motion of virtually the entire lithosphere, providing a means to distinguish TPW from continental drift. We performed thermal demagnetization on remaining samples from Ocean Drilling Program (ODP) Site 801B, which were cored from the oldest sampled oceanic crust in the Western Pacific, to determine its change in paleolatitude during the Late Jurassic and Early Cretaceous (167 - 134 Ma). We find that the Pacific Plate likely underwent a steady southward drift during this time period, consistent with previous results from magnetic anomalies, except for an episode of northward motion between Oxfordian and Tithonian time (161 - 147 Ma). Although the amplitude of this northward shift is subject to significant uncertainty due to the sparse recovery of core samples, the trajectory of the Pacific Plate is most simply explained by TPW in the 160 - 145 Ma interval as inferred from continental data. Furthermore, such an interpretation is consistent with the sense of shear inferred at the Farallon-North American Plate boundary, whereas uniform

Exotic Members of Southern Alaska's Jurassic Arc

NASA Astrophysics Data System (ADS)

Todd, E.; Jones, J. V., III; Karl, S. M.; Box, S.; Haeussler, P. J.

2017-12-01

The Jurassic Talkeetna arc and contemporaneous plutonic rocks of the Alaska-Aleutian Range batholith (ARB) are key components of the Peninsular terrane of southern Alaska. The Talkeetna arc, considered to be a type example of an intra-oceanic arc, was progressively accreted to northwestern North America in the Jurassic to Late Cretaceous, together with associated components of the Wrangellia Composite terrane. Older Paleozoic and Mesozoic rock successions closely associated with the ARB suggest that at least part of the Peninsular terrane might be an overlap succession built on pre-existing crust, possibly correlative with the Wrangellia terrane to the east. However, the relationship between the Talkeetna arc, ARB, and any pre-existing crust remains incompletely understood. Field investigations focused on the petrogenesis of the ARB near Lake Clark National Park show that Jurassic to Late Cretaceous plutonic rocks commonly host a diverse range of mineralogically distinct xenolith inclusions, ranging in size from several cm to hundreds of meters. The modal fraction of these inclusions ranges from <1% to >50% in some outcrops. They are generally mafic in composition and, with few exceptions, are more mafic than host plutonic rocks, although they are observed as both igneous (e.g., gabbro cumulate, diorite porphyry) and metamorphic types (e.g., amphibolite, gneiss and quartzite). Inclusion shapes range from angular to rounded with sharp to diffuse boundaries and, in some instances, are found as planar, compositionally distinct bands or screens containing high-temperature ductile shear fabrics. Other planar bands are more segmented, consistent with lower-temperature brittle behavior. Comparison of age, geochemical fractionation trends, and isotope systematics between the inclusions and host plutons provides a critical test of whether they are co-genetic with host plutons. Where they are related, mafic inclusions provide clues about magmatic evolution and fractionation

Episodic Jurassic to Lower Cretaceous intraplate compression in Central Patagonia during Gondwana breakup

NASA Astrophysics Data System (ADS)

Navarrete, César; Gianni, Guido; Echaurren, Andrés; Kingler, Federico Lince; Folguera, Andrés

2016-12-01

From Lower Jurassic to Lower Cretaceous, several intraplate compression events affected discrete sectors of Central Patagonia, under a general context of crustal extension associated with Gondwana breakup. This was demonstrated by means of 2D and 3D seismic and borehole data, which show partial inversion of Lower and Middle Jurassic extensional structures of the Chubut and Cañadón Asfalto basins, during the earliest stages of breakup. A comparison with surrounding areas in Patagonia, where similar Jurassic intraplate compression was described, allowed the discrimination of three discrete pulses of subtle compression (C1: ∼188-185 Ma; C2: ∼170-163; C3: ∼157-136? Ma). Interestingly, episodic intraplate compressional events are closely followed by high flux magmatic events linked to the westward expansion of the Karoo-Ferrar thermal anomaly, which impacted on the lithosphere of southwest Gondwana in Lower Jurassic. In addition, we determined the approximate direction of the main compressive strain (σ1) compatible with other Jurassic intraplate belts of South America. These observations led us to propose a linkage between a thermo mechanically weakened continental crust due to LIPs activity, changes in plate motions and ridge-push forces generated by the opening of the Weddell Sea, in order to explain intraplate shortening, interrupted while Karoo LIPs magmatic invigoration took place.

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

2016-06-01

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

The First Metriorhynchid Crocodylomorph from the Middle Jurassic of Spain, with Implications for Evolution of the Subclade Rhacheosaurini

PubMed Central

Parrilla-Bel, Jara; Young, Mark T.; Moreno-Azanza, Miguel; Canudo, José Ignacio

2013-01-01

Background Marine deposits from the Callovian of Europe have yielded numerous species of metriorhynchid crocodylomorphs. While common in English and French Formations, metriorhynchids are poorly known from the Iberian Peninsula. Twenty years ago an incomplete, but beautifully preserved, skull was discovered from the Middle Callovian of Spain. It is currently the oldest and best preserved metriorhynchid specimen from the Iberian Peninsula. Until now it has never been properly described and its taxonomic affinities remained obscure. Methodology/Principal Findings Here we present a comprehensive description for this specimen and in doing so we refer it to a new genus and species: Maledictosuchus riclaensis. This species is diagnosed by numerous autapomorphies, including: heterodont dentition; tightly interlocking occlusion; lachrymal anterior process excludes the jugal from the preorbital fenestra; orbits longer than supratemporal fenestrae; palatine has two non-midline and one midline anterior processes. Our phylogenetic analysis finds Maledictosuchus riclaensis to be the basal-most known member of Rhacheosaurini (the subclade of increasingly mesopelagic piscivores that includes Cricosaurus and Rhacheosaurus). Conclusions/Significance Our description of Maledictosuchus riclaensis shows that the craniodental morphologies that underpinned the success of Rhacheosaurini in the Late Jurassic and Early Cretaceous, as a result of increasing marine specialization to adaptations for feeding on fast small-bodied prey (i.e. divided and retracted external nares; reorientation of the lateral processes of the frontal; elongate, tubular rostrum; procumbent and non-carinated dentition; high overall tooth count; and dorsolaterally inclined paroccipital processes), first appeared during the Middle Jurassic. Rhacheosaurins were curiously rare in the Middle Jurassic, as only one specimen of Maledictosuchus riclaensis is known (with no representatives discovered from the well

Four new species of hangingflies (Insecta, Mecoptera, Bittacidae) from the Middle Jurassic of northeastern China.

PubMed

Liu, Sulin; Shih, Chungkun; Ren, Dong

2014-01-01

Two new species of Mongolbittacus Petrulevičius, Huang & Ren, 2007, Mongolbittacusspeciosus sp. n. and Mongolbittacusoligophlebius sp. n., and two new species of Exilibittacus Yang, Ren & Shih, 2012, Exilibittacusfoliaceus sp. n. and Exilibittacusplagioneurus sp. n., in the family Bittacidae, are described and illustrated based on five well-preserved fossil specimens. These specimens were collected from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. These new findings enhance our understanding of the morphological characters of early hangingflies and highlight the diversity of bittacids in the Mid Mesozoic ecosystems.

He Will Lift Up His Head: A Report to the Developmental Disabilities Office on the Situation of Handicapped Navajos and the Implications Thereof for All Native Americans.

ERIC Educational Resources Information Center

Haskins, James S.; Stifle, J. M.

Issues involved in education of handicapped Navajo children are examined. Background sections contrast the history of treatment for the handicapped in America with the treatment received by handicapped Navajos. Unemployment, substandard housing, lack of accessibility within the reservation, overpopulation, language barriers, and the relationship…

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…

Cultural elements underlying the community health representative - client relationship on Navajo Nation.

PubMed

Gampa, Vikas; Smith, Casey; Muskett, Olivia; King, Caroline; Sehn, Hannah; Malone, Jamy; Curley, Cameron; Brown, Chris; Begay, Mae-Gilene; Shin, Sonya; Nelson, Adrianne Katrina

2017-01-09

Navajo Nation Community Health Representatives (CHR) are trained community health workers (CHWs) who provide crucial services for patients and families. The success of the CHRs' interventions depends on the interactions between the CHRs and their clients. This research investigates the culturally specific factors that build and sustain the CHR-client interaction. In-depth interviews were conducted with 16 CHRs on Navajo Nation. Interviews were transcribed and coded according to relevant themes. Code summaries were organized into a narrative using grounded theory techniques. The analysis revealed four findings critical to the development of a CHR-client relationship. Trust is essential to this relationship and provides a basis for providing quality services to the client. The ability to build and maintain trust is defined by tradition and culture. CHRs must be respectful of the diverse traditional and social practices. Lastly, the passing of clients brings together the CHR, the client's family, and the community. Understanding the cultural elements of the CHR-client relationship will inform the work of community partners, clinical providers, and other indigenous communities working to strengthen CHR programs and obtain positive health outcomes among marginalized communities.

Increasing Vulnerability to Drought and Climate Change on the Navajo Nation, southwestern United States

NASA Astrophysics Data System (ADS)

Hiza, M. M.; Kelley, K. B.; Francis, H.

2011-12-01

The Navajo Nation of Arizona, New Mexico, and Utah, is an ecologically sensitive semi-arid to arid area where rapid growth of one of the largest population of Native Americans is outstripping the capacity of the land to sustain them. Recent drought conditions, combined with increasing temperatures, are significantly altering the habitability of a region already characterized by harsh living conditions. In addition to altered landscape conditions due to climatic change, drought, and varying land use practices over the last 200 years, the Navajo people have been affected by land use policies and harsh economic conditions that weaken their cultural fabric. Increasing aridity combined with drought threaten the very existence of Navajo culture and the survival of traditional Navajo communities. People presently living on these Native lands are unique in American society as their traditional lifestyle requires intimate knowledge of the ecosystem, knowledge that has been passed on for generations through oral traditions. We present data from the lifelong observations of 73 Native American elders that provide a record of the changes in plants and animals, water availability, weather, and sand or dust storms. This information is used to complement the scant long-term meteorological records and historical documentation for the region to further refine our understanding of the historical trends and local impacts of climate change and drought. Among the most cited changes is a long-term decrease in the amount of annual snowfall over the past century, a transition from wet conditions to dry conditions in the 1940s, and a decline in surface water features. The lack of available water, in addition to changing socioeconomic conditions, was mentioned as a leading cause for the decline in the ability to grow corn and other crops. Other noted changes include the disappearance of springs, and of plant and animal populations (particularly medicinal plants, cottonwood trees, beavers

Late Jurassic low latitude of Central Iran: paleogeographic and tectonic implications

NASA Astrophysics Data System (ADS)

Mattei, Massimo; Muttoni, Giovanni; Cifelli, Francesca

2014-05-01

The individual blocks forming present-day Central Iran are now comprised between the Zagros Neo-Tethys suture to the south and the Alborz Palaeo-Tethys suture to the north. At the end of the Palaeozoic, the Iranian blocks rifted away from the northern margin of Gondwana as consequence of the opening of the Neo-Tethys, and collided with Eurasia during the Late Triassic, giving place to the Eo-Cimmerian orogeny. From then on, the Iranian block(s) should have maintained European affinity. Modern generations of apparent polar wander paths (APWPs) show the occurrence in North American and African coordinates of a major and rapid shift in pole position (=plate shift) during the Middle-Late Jurassic. This so-called monster polar shift is predicted also for Eurasia from the North Atlantic plate circuit, but Jurassic data from this continent are scanty and problematic. Here, we present paleomagnetic data from the Kimmeridgian-Tithonian (Upper Jurassic) Garedu Formation of Iran. Paleomagnetic component directions of primary (pre-folding) age indicate a paleolatitude of deposition of 10°N ± 5° that is in excellent agreement with the latitude drop predicted for Iran from APWPs incorporating the Jurassic monster polar shift. We show that paleolatitudes calculated from these APWPs, used in conjunction with simple zonal climate belts, better explain the overall stratigraphic evolution of Iran during the Mesozoic.

Comment on "Astronomical constraints on the duration of the Early Jurassic Pliensbachian Stage and global climatic fluctuations" [Earth Planet. Sci. Lett. 455 (2016) 149-165

NASA Astrophysics Data System (ADS)

Smith, David G.; Bailey, Robin J.

2018-01-01

Astrochronology employs spectral analysis of stratigraphic data series to substantiate and quantify depositional cyclicity, and thus to establish a probable causal link between cases of rhythmic bedding and periodic orbitally-forced climate change. Vaughan et al. (2011 - not cited by Ruhl et al.) showed that the spectral methods conventionally used in cyclostratigraphy will generate false positive results - they will identify multiple cycles that are not present in the data. Tests with synthetic random datasets are both a simple and an essential way to prove this. Ruhl et al. (2016) used the methods to which these criticisms apply in their analysis of XRF-compositional data series from the Early Jurassic of the Mochras borehole, Wales. We use properly corrected methods to re-examine some of their data, showing that their spectral results are not valid, thus casting doubt on their proposed calibration of Pliensbachian time.

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.

Middle Jurassic Radiolaria from a siliceous argillite block in a structural melange zone near Viqueque, Timor Leste: Paleogeographic implications

NASA Astrophysics Data System (ADS)

Haig, David W.; Bandini, Alexandre Nicolas

2013-10-01

Thin-bedded siliceous argillite forming a large block within a structural melange zone at Viqueque, Timor Leste, has yielded a Middle Jurassic (late Bathonian-early Callovian) radiolarian assemblage belonging to Unitary Association Zone 7. Fifty-five species are recognized and illustrated, forming the most diverse radiolarian fauna yet documented from the Jurassic of Timor. The fauna shows little similarity in species content to the few other assemblages previously listed from the Middle or Late Jurassic of Timor, and also has few species in common with faunas known elsewhere in the region from Rotti, Sumatra, South Kalimantan, and Sula. Based on lithofacies similarities and age, the siliceous argillite succession in the melange block at Viqueque is included in the Noni Group originally described as the lower part of the Palelo Series in West Timor. In terms of lithofacies, the Noni Group is distinct from other stratigraphic units known in Timor. It may be associated with volcanic rocks but age relationships are uncertain, although some of the radiolarian cherts in the Noni Group in West Timor have been reported to include tuffaceous sediment. The deep-water character of the siliceous hemipelagite-pelagite facies, the probable volcanic association, and an age close to that of continental breakup in the region suggest deposition in a newly rifted Indian Ocean. In Timor's tectonostratigraphic classification scheme, the Noni Group is here placed in the "Indian Ocean Megasequence".

Grants to Indian-Controlled Postsecondary Educational Institutions and the Navajo Community College Act. Hearing Before the United States Senate Select Committee on Indian Affairs, 95th Congress, 1st Session on S. 468 - To Amend the Navajo Community College Act; S. 1215 - To Provide for Grants to Indian-Controlled Postsecondary Educational Institutions, and for Other Purposes (July 28, 1977).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Senate Select Committee on Indian Affairs.

Presenting testimony, these 1977 Senate Hearings deal with S. 468, a bill designed to amend the Navajo Community College Act of 1971 to insure adequate funding for operation and expansion of the college on the Navajo Reservation, and S. 1215, designed to amend the Indian Self Determination and Education Assistance Act of 1975 by adding a third…

A re-examination of paleomagnetic results from NA Jurassic sedimentary rocks: Additional evidence for proposed Jurassic MUTO?

NASA Astrophysics Data System (ADS)

Housen, B. A.

2015-12-01

Kent and Irving, 2010; and Kent et al, 2015 propose a monster shift in the position of Jurassic (160 to 145 Ma) paleopoles for North America- defined by results from igneous rocks. This monster shift is likely an unrecognized true polar wander occurrence. Although subject to inclination error, results from sedimentary rocks from North America, if corrected for these effects, can be used to supplement the available data for this time period. Steiner (2003) reported results from 48 stratigraphic horizons sampled from the Callovian Summerville Fm, from NE New Mexico. A recalculated mean of these results yields a mean direction of D = 332, I = 39, n=48, k = 15, α95 = 5.4°. These data were analyzed for possible inclination error-although the dataset is small, the E-I results yielded a corrected I = 53. This yields a corrected paleopole for NA at ~165 Ma located at 67° N and 168° E.Paleomagnetic results from the Black Hills- Kilanowski (2002) for the Callovian Hulett Mbr of the Sundance Fm, and Gregiore (2001) the Oxfordian-Tithonian Morrison Fm (Gregiore, 2001) have previously been interpreted to represent Eocene-aged remagnetizations- due to the nearly exact coincidence between the in-situ pole positions of these Jurassic units with the Eocene pole for NA. Both of the tilt-corrected results for these units have high latitude poles (Sundance Fm: 79° N, 146° E; Morrison Fm: 89° N, 165° E). An E-I analysis of these data will be presented- using a provisional inclination error of 10°, corrected paleopoles are: (Sundance Fm: 76° N, 220° E; Morrison Fm: 77° N, 266° E). The Black Hills 165 Ma (Sundance Fm) and 145 Ma (Morrison Fm) poles, provisionally corrected for 10° inclination error- occur fairly close to the NA APWP proposed by Kent et al, 2015- using an updated set of results from kimberlites- the agreement between the Sundance Fm and the Triple-B (158 Ma) pole would be nearly exact with a slightly lesser inclination error. The Summerville Fm- which is

A palaeoequatorial ornithischian and new constraints on early dinosaur diversification.

PubMed

Barrett, Paul M; Butler, Richard J; Mundil, Roland; Scheyer, Torsten M; Irmis, Randall B; Sánchez-Villagra, Marcelo R

2014-09-22

Current characterizations of early dinosaur evolution are incomplete: existing palaeobiological and phylogenetic scenarios are based on a fossil record dominated by saurischians and the implications of the early ornithischian record are often overlooked. Moreover, the timings of deep phylogenetic divergences within Dinosauria are poorly constrained owing to the absence of a rigorous chronostratigraphical framework for key Late Triassic-Early Jurassic localities. A new dinosaur from the earliest Jurassic of the Venezuelan Andes is the first basal ornithischian recovered from terrestrial deposits directly associated with a precise radioisotopic date and the first-named dinosaur from northern South America. It expands the early palaeogeographical range of Ornithischia to palaeoequatorial regions, an area sometimes thought to be devoid of early dinosaur taxa, and offers insights into early dinosaur growth rates, the evolution of sociality and the rapid tempo of the global dinosaur radiation following the end-Triassic mass extinction, helping to underscore the importance of the ornithischian record in broad-scale discussions of early dinosaur history. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

An early extensional event of the South China Block during the Late Mesozoic recorded by the emplacement of the Late Jurassic syntectonic Hengshan Composite Granitic Massif (Hunan, SE China)

NASA Astrophysics Data System (ADS)

Wei, Wei; Chen, Yan; Faure, Michel; Martelet, Guillaume; Lin, Wei; Wang, Qingchen; Yan, Quanren; Hou, Quanlin

2016-03-01

Continental scaled extension is the major Late Mesozoic (Jurassic and Cretaceous) tectonic event in East Asia, characterized by faulting, magmatic intrusions and half-grabens in an area with a length of > 5000 km and a width of > 1000 km. Numerous studies have been conducted on this topic in the South China Block (SCB), However, the space and time ranges of the compressional or extensional regimes of the SCB during the Jurassic are still unclear, partly due to the lack of structural data. The emplacement fabrics of granitic plutons can help determine the regional tectonic background. In this study, a multidisciplinary approach, including Anisotropy of Magnetic Susceptibility (AMS), macro and microstructural analyses, quartz c-axis preferred orientation, gravity modeling and monazite EPMA dating, was conducted on the Hengshan composite granitic massif in SCB that consists of the Triassic Nanyue biotite granitic pluton and the Late Jurassic Baishifeng two-mica granitic pluton. The magnetic fabrics are characterized by a consistent NW-SE oriented lineation and weakly inclined foliation. A dominant high temperature deformation with a top-to-the-NW shear sense is identified for both plutons. The deformation increasing from the center of the Baishifeng pluton to its western border is associated to the development of the West Hengshan Boundary Fault (WHBF). The gravity modeling shows a ;saw tooth-shaped; NE-SW oriented structure of the Baishifeng pluton, which may be considered as NE-SW oriented tension-gashes formed due to the NW-SE extension. All results show that the Triassic Nanyue pluton was deformed under post-solidus conditions by the WHBF coeval with the emplacement of the Late Jurassic Baishifeng pluton. All these observations comply with the NW-SE extensional tectonics coeval with the emplacement of the Baishifeng pluton, which argues that the NW-SE crustal stretching started since the Late Jurassic, at least in this part of the SCB.

Early Jurassic hydrothermal vent community from the Franciscan Complex, San Rafael Mountains, California

NASA Astrophysics Data System (ADS)

Little, Crispin T. S.; Herrington, Richard J.; Haymon, Rachel M.; Danelian, Taniel

1999-02-01

The Figueroa massive sulfide deposit, located in Franciscan Complex rocks in the San Rafael Mountains of California, preserves the only known Jurassic hydrothermal vent fossils. The Figueroa fossil assemblage is specimen rich but of low diversity and comprises, in order of decreasing abundance, vestimentiferan worm tubes, the rhynchonellid brachiopod Anarhynchia cf. gabbi and a species of ?nododelphinulid gastropod. The Figueroa fossil organisms lived at a deep-water, high-temperature vent site located on a mid-ocean ridge or seamount at an equatorial latitude. The fossil vent site was then translated northwestward by the motion of the Farallon plate and was subsequently accreted to its present location. An iron-silica exhalite bed, the probable lateral equivalent of the Figueroa deposit, contains abundant filamentous microfossils with two distinct morphologies and probably represents a lower-temperature, diffuse-flow environment. The Figueroa fossil community was subject to the same environmental conditions as modern vent communities, but it is unique among modern and other fossil vent communities in having rhynchonellid brachiopods.

Hg concentrations from Late Triassic and Early Jurassic sedimentary rocks: first order similarities and second order depositional and diagenetic controls

NASA Astrophysics Data System (ADS)

Yager, J. A.; West, A. J.; Bergquist, B. A.; Thibodeau, A. M.; Corsetti, F. A.; Berelson, W.; Bottjer, D. J.; Rosas, S.

2016-12-01

Mercury concentrations in sediments have recently gained prominence as a potential tool for identifying large igneous province (LIP) volcanism in sedimentary records. LIP volcanism coincides with several mass extinctions during the Phanerozoic, but it is often difficult to directly tie LIP activity with the record of extinction in marine successions. Here, we build on mercury concentration data reported by Thibodeau et al. (Nature Communications, 7:11147, 2016) from the Late Triassic and Early Jurassic of New York Canyon, Nevada, USA. Increases in Hg concentrations in that record were attributed to Central Atlantic Magmatic Province (CAMP) activity in association with the end-Triassic mass extinction. We expand the measured section from New York Canyon and report new mercury concentrations from Levanto, Peru, where dated ash beds provide a discrete chronology, as well as St. Audrie's Bay, UK, a well-studied succession. We correlate these records using carbon isotopes and ammonites and find similarities in the onset of elevated Hg concentrations and Hg/TOC in association with changes in C isotopes. We also find second order patterns that differ between sections and may have depositional and diagenetic controls. We will discuss these changes within a sedimentological framework to further understand the controls on Hg concentrations in sedimentary records and their implications for past volcanism.

Paleoenvironments of the Jurassic and Cretaceous Oceans: Selected Highlights

NASA Astrophysics Data System (ADS)

Ogg, J. G.

2007-12-01

There are many themes contributing to the sedimentation history of the Mesozoic oceans. This overview briefly examines the roles of the carbonate compensation depth (CCD) and the associated levels of atmospheric carbon dioxide, of the evolution of marine calcareous microplankton, of major transgressive and regressive trends, and of super-plume eruptions. Initiation of Atlantic seafloor spreading in the Middle Jurassic coincided with an elevated carbonate compensation depth (CCD) in the Pacific-Tethys mega-ocean. Organic-rich sediments that would become the oil wealth of regions from Saudi Arabia to the North Sea were deposited during a continued rise in CCD during the Oxfordian-early Kimmeridgian, which suggests a possible increase in carbon dioxide release by oceanic volcanic activity. Deep-sea deposits in near-equatorial settings are dominated by siliceous shales or cherts, which reflect the productivity of siliceous microfossils in the tropical surface waters. The end-Jurassic explosion in productivity by calcareous microplankton contributed to the lowering of the CCD and onset of the chalk ("creta") deposits that characterize the Tithonian and lower Cretaceous in all ocean basins. During the mid-Cretaceous, the eruption of enormous Pacific igneous provinces (Ontong Java Plateau and coeval edifices) increased carbon dioxide levels. The resulting rise in CCD terminated chalk deposition in the deep sea. The excess carbon was progressively removed in widespread black-shale deposits in the Atlantic basins and other regions - another major episode of oil source rock. A major long-term transgression during middle and late Cretaceous was accompanied by extensive chalk deposition on continental shelves and seaways while the oceanic CCD remained elevated. Pacific guyots document major oscillations (sequences) of global sea level superimposed on this broad highstand. The Cretaceous closed with a progressive sea-level regression and lowering of the CCD that again enabled

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…

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…

Mochras Revisited: a new global standard for 25 million years of Jurassic Earth history - A drilling proposal for the International Continental Drilling Programme

NASA Astrophysics Data System (ADS)

Hesselbo, Stephen; Bjerrum, Christian; Hinnov, Linda; Mac Niocaill, Conall; Miller, Kenneth; Riding, James; van de Schootbrugge, Bas; Wonik, Thomas

2014-05-01

The Early Jurassic Epoch (201.4 - 175 Ma) was a time of extreme environmental change. Through this period there are well-documented examples of rapid transitions from cold, or even glacial climates, through to super-greenhouse events, the latter characterized worldwide by hugely enhanced organic carbon burial, multiple large-magnitude isotopic anomalies, global sea-level changes, and mass extinctions. These events not only reflect changes in the global climate system but are also thought to have had significant influence on the evolution of Jurassic marine and terrestrial biota. Furthermore, the events may serve as analogues for present-day and future environmental transitions. Although our knowledge of specific global change events within the Early Jurassic is rapidly improving, a prime case-in-point being the Toarcian Oceanic Anoxic Event (or T-OAE), we have neither documented all the events, nor do we have a comprehensive understanding of their timing, pacing, or triggers. A key factor contributing to our fragmentary knowledge is the scattered and discontinuous nature of the existing datasets. The major goal for this proposed ICDP project is therefore to produce a new global standard for these key 25 million years of Earth history by re-drilling a 45 year old borehole at Mochras Farm on the edge of Cardigan Bay, Wales, and to develop an integrated stratigraphy for the cored material, as well as high-resolution proxy-records of environmental change. The new datasets will be applied to understand fundamental questions about the long- and short-term evolution of the Earth System.

Inland termination of the Weddell Sea Rift against a major Jurassic strike-slip fault zone between East and West Antarctica

NASA Astrophysics Data System (ADS)

Jordan, Tom; Ferraccioli, Fausto; Leat, Phil; Ross, Neil; Bingham, Rob; Rippin, David; LeBrocq, Anne; Corr, Hugh; Siegert, Martin

2013-04-01

The Weddell Sea Embayment (WSE) lies in a key position to study the nature of the tectonic boundary between East and West Antarctica and the development of continental rifting processes and magmatism during the early stages of Gondwana break-up. Evidence for continental rifting within the WSE derives from previous reconnaissance geophysical investigations offshore and geological studies of the associated Jurassic magmatism onshore. Seismic data reveal high stretching factors beneath the Weddell Sea Rift (WSR) between 1.5 and 3.0, and gravity data suggest a crustal thickness of ca 27 km and an effective elastic thickness of ~35 km for the rifted region. Geochemical interpretations indicate that a Middle Jurassic LIP, including extensive mafic tholeiites and some Jurassic granitic intrusions may be related to a superplume that impinged beneath the WSE. Here we present results from a recent aerogeophysical investigation that sheds new light into the previously largely unknown inland extent of the WSR beneath the West Antarctic Ice Sheet. This includes new insights into its magmatic patterns, as well as the nature of its tectonic boundaries with the adjacent Ellsworth-Whitmore block (EWM) and the margin of East Antarctica. Aeromagnetic images were interpreted to reveal pre-rift rocks, including Proterozoic basement, Middle Cambrian rift-related volcanics and metasediments and rift-related Jurassic granitoids. Magnetic depth-to-source estimates were calculated and help constrain two joint magnetic and gravity forward models for the study region. These models were used to assess crustal thickness variations, the extent of Proterozoic basement, and the thickness of Jurassic intrusions and inferred post-Jurassic sedimentary infill. The Jurassic granitoids were modelled as 5-8 km thick. These intrusions include roughly circular plutons, emplaced at the transition between the thicker crust of the EWM block and the thinner crust of the WSR, and more elongated bodies emplaced

Earliest evolution of multituberculate mammals revealed by a new Jurassic fossil.

PubMed

Yuan, Chong-Xi; Ji, Qiang; Meng, Qing-Jin; Tabrum, Alan R; Luo, Zhe-Xi

2013-08-16

Multituberculates were successful herbivorous mammals and were more diverse and numerically abundant than any other mammal groups in Mesozoic ecosystems. The clade also developed diverse locomotor adaptations in the Cretaceous and Paleogene. We report a new fossil skeleton from the Late Jurassic of China that belongs to the basalmost multituberculate family. Dental features of this new Jurassic multituberculate show omnivorous adaptation, and its well-preserved skeleton sheds light on ancestral skeletal features of all multituberculates, especially the highly mobile joints of the ankle, crucial for later evolutionary success of multituberculates in the Cretaceous and Paleogene.

The Late Jurassic Panjeh submarine volcano in the northern Sanandaj-Sirjan Zone, northwest Iran: Mantle plume or active margin?

NASA Astrophysics Data System (ADS)

Azizi, Hossein; Lucci, Federico; Stern, Robert J.; Hasannejad, Shima; Asahara, Yoshihiro

2018-05-01

The tectonic setting in which Jurassic igneous rocks of the Sanandaj-Sirjan Zone (SaSZ) of Iran formed is controversial. SaSZ igneous rocks are mainly intrusive granodiorite to gabbroic bodies, which intrude Early to Middle Jurassic metamorphic basement; Jurassic volcanic rocks are rare. Here, we report the age and petrology of volcanic rocks from the Panjeh basaltic-andesitic rocks complex in the northern SaSZ, southwest of Ghorveh city. The Panjeh magmatic complex consists of pillowed and massive basalts, andesites and microdioritic dykes and is associated with intrusive gabbros; the overall sequence and relations with surrounding sediments indicate that this is an unusually well preserved submarine volcanic complex. Igneous rocks belong to a metaluminous sub-alkaline, medium-K to high-K calc-alkaline mafic suite characterized by moderate Al2O3 (13.7-17.6 wt%) and variable Fe2O3 (6.0-12.6 wt%) and MgO (0.9-11.1 wt%) contents. Zircon U-Pb ages (145-149 Ma) define a Late Jurassic (Tithonian) age for magma crystallization and emplacement. Whole rock compositions are enriched in Th, U and light rare earth elements (LREEs) and are slightly depleted in Nb, Ta and Ti. The initial ratios of 87Sr/86Sr (0.7039-0.7076) and εNd(t) values (-1.8 to +4.3) lie along the mantle array in the field of ocean island basalts and subcontinental metasomatized mantle. Immobile trace element (Ti, V, Zr, Y, Nb, Yb, Th and Co) behavior suggests that the mantle source was enriched by fluids released from a subducting slab (i.e. deep-crustal recycling) with some contribution from continental crust for andesitic rocks. Based the chemical composition of Panjeh mafic and intermediate rocks in combination with data for other gabbroic to dioritic bodies in the Ghorveh area we offer two interpretations for these (and other Jurassic igneous rocks of the SaSZ) as reflecting melts from a) subduction-modified OIB-type source above a Neo-Tethys subduction zone or b) plume or rift tectonics involving

Four new species of hangingflies (Insecta, Mecoptera, Bittacidae) from the Middle Jurassic of northeastern China

PubMed Central

Liu, Sulin; Shih, Chungkun; Ren, Dong

2014-01-01

Abstract Two new species of Mongolbittacus Petrulevičius, Huang & Ren, 2007, Mongolbittacus speciosus sp. n. and Mongolbittacus oligophlebius sp. n., and two new species of Exilibittacus Yang, Ren & Shih, 2012, Exilibittacus foliaceus sp. n. and Exilibittacus plagioneurus sp. n., in the family Bittacidae, are described and illustrated based on five well-preserved fossil specimens. These specimens were collected from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. These new findings enhance our understanding of the morphological characters of early hangingflies and highlight the diversity of bittacids in the Mid Mesozoic ecosystems. PMID:25610337

American Jurassic symmetrodonts and Rhaetic "pantotheres".

PubMed

Crompton, A W; Jenkins, F A

1967-02-24

The molar morphology of the symmetrodonts Tinodon and Eurylambda from the late Jurassic of North America is virtually identical to that of so-called "pantotheres" from the Rhaetic of Wales. Therefore a primitive symmetrodont molar pattern was probably present in the phylogeny of pantotherian and tribosphenic molars. Occlusion of Tinodon and Eurylambda produced complex wear facets unlike the simple trigon-trigonid shear surfaces of Spalacotherium and Peralestes.

Regional Jurassic Submarine Arc-Apron Complex in the Northern Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Templeton, J. H.; Hanson, R. E.; Hargrove, U. S.; Ruff, K. L.

2005-05-01

The Tuttle Lake Formation (TLF), a distinctive unit forming part of the wall rocks to the Mesozoic Sierra Nevada batholith in northern California, is interpreted to have developed within a major island arc fringing the western margin of North America during the Jurassic. It extends for 75 km along strike, from mountainous terrain NW of Truckee to the Mt. Tallac pendant SW of Lake Tahoe. Superb glaciated exposures at various locations along strike provide a window into the proximal parts of a submarine Jurassic arc-apron complex. The TLF is >4 km thick and consists mainly of massively bedded, matrix-supported, polymict volcanic breccias containing poorly vesicular, subangular to angular basaltic to andesitic clasts up to 2 m in length. Characteristics of the polymict breccias indicate deposition from submarine debris flows derived from slumping of near-vent accumulations of lithic debris or sector collapse of parts of the volcanic edifice. Interbeds of finer grained andesitic and silicic turbidites and ash-fall tuffs occur sparsely within the debris-flow sequence, as do volumetrically minor pillow-hyaloclastite breccias, recording local extrusion of lavas on the seafloor. Coarse-grained TLF debris-flow deposits abruptly overlie the Early to Middle Jurassic Sailor Canyon Formation, which consists dominantly of andesitic volcanic sandstones and mudstones deposited from distal turbidity currents in a long-lived, deep marine basin. This marked lithologic change records rapid influx of coarse-grained volcanogenic detritus into the Sailor Canyon basin, related to a major shift in position of volcanic centers. Available data show that the TLF accumulated in a narrow time frame in the Middle Jurassic, just prior to regional tilting and batholith emplacement at ~165 Ma. Coeval basaltic to andesitic hypabyssal intrusions typically compose >15% of the exposed area of the TLF. They have identical major- and trace-element compositions and REE patterns to clasts within the host

Records of wells in sandstone and alluvial aquifers and chemical data for water from selected wells in the Navajo aquifer in the vicinity ofthe Greater Aneth Oil Field, San Juan County, Utah

USGS Publications Warehouse

Spangler, Lawrence E.

1992-01-01

This report contains hydrologic data for wells finished in sandstone and alluvial aquifers in southeastern San Juan County, Utah, and chemical data for water from selected wells in the Navajo aquifer. Temperature, specific conductance, pH, and discharge data from 1989-91 for water from selected wells in all aquifers are also presented.Data presented in this report were compiled from previously published reports (Goode, 1958; Sumsion, 1975; Avery, 1986; Kimball, 1987; Howells, 1990); data bases of the U.S. Geological Survey, the Navajo Tribe, the U.S. Bureau of Land Management, the Utah Division of Water Rights, and the Utah Division of Oil, Gas, and Mining; and from information obtained from oil companies in the Greater Aneth Oil Field. Results of investigations by Avery (1986) during 1982-83 indicated that water from many wells in the Navajo aquifer in the vicinity of the Greater Aneth Oil Field was moderately saline and that in some wells, salinity appeared to increase over time. The purpose of this study is to assess the physical extent and concentration of saline water in the Navajo and other aquifers in this area. The purpose of this report is to present available water-quality data for water from wells in the Navajo aquifer and present records for selected wells in the Navajo and other aquifers.

Our Community -- Today and Yesterday. Book One (Nihil Hahoodzodoo -- Diijiidi doo Adaadaa. Naaltsoos T'aala'i Gone Yits'iligii). Fourth Grade Navajo Bilingual-Bicultural Social Studies Curriculum.

ERIC Educational Resources Information Center

Bia, Fred; And Others

Presented in five chapters, book 1 of the Rough Rock fourth grade Navajo social studies program text is written in Navajo and English. The first chapter is on the community of Rough Rock (Arizona) illustrated by photographs of the community and people. Chapter II discusses the four elements (air, water, earth, and fire) the community needs to…

Bedrock and surficial geologic map of the Satan Butte and Greasewood 7.5’ quadrangles, Navajo and Apache Counties, northern Arizona

USGS Publications Warehouse

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

2013-01-01

The geologic map of the Satan Butte and Greasewood 7.5’ quadrangles is the result of 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 map provides geologic information useful for range management, plant and animal studies, flood control, water resource investigations, and natural hazards associated with sand-dune mobility. The map provides connectivity to the regional geologic framework of the Grand Canyon area of northern Arizona. The map area encompasses approximately 314 km2 (123 mi2) within Navajo and Apache Counties of northern Arizona and is bounded by lat 35°37'30" to 35°30' N., long 109°45' to 110° W. The quadrangles lie within the southern Colorado Plateau geologic province and within the northeastern portion of the Hopi Buttes (Tsézhin Bií). Large ephemeral drainages, Pueblo Colorado Wash and Steamboat Wash, originate north of the map area on the Defiance Plateau and Balakai Mesa respectively. Elevations range from 1,930 m (6,330 ft) at the top of Satan Butte to about 1,787 m (5,860 ft) at Pueblo Colorado Wash where it exits the southwest corner of the Greasewood quadrangle. The only settlement within the map area is Greasewood, Arizona, on the north side of Pueblo Colorado Wash. Navajo Highway 15 crosses both quadrangles and joins State Highway 264 northwest of Ganado. Unimproved dirt roads provide access to remote parts of the Navajo Reservation.

Carbon cycle history through the Middle Jurassic (Aalenian - Bathonian) of the Mecsek Mountains, Southern Hungary

NASA Astrophysics Data System (ADS)

Price, Gregory D.; Főzy, István; Galácz, András

2018-04-01

A carbonate carbon isotope curve from the Aalenian-Bathonian interval is presented from the Óbánya valley, of the Mecsek Mountains, Hungary. This interval is certainly less well constrained and studied than other Jurassic time slices. The Óbánya valley lies in the eastern part of the Mecsek Mountains, between Óbánya and Kisújbánya and provides exposures of an Aalenian to Lower Cretaceous sequence. It is not strongly affected by tectonics, as compared to other sections of eastern Mecsek of the same age. In parts, a rich fossil assemblage has been collected, with Bathonian ammonites being especially valuable at this locality. The pelagic Middle Jurassic is represented by the Komló Calcareous Marl Formation and thin-bedded limestones of the Óbánya Limestone Formation. These are overlain by Upper Jurassic siliceous limestones and radiolarites of the Fonyászó Limestone Formation. Our new data indicate a series of carbon isotope anomalies within the late Aalenian and early-middle Bajocian. In particular, analysis of the Komló Calcareous Marl Formation reveals a negative carbon isotope excursion followed by positive values that occurs near the base of the section (across the Aalenian-Bajocian boundary). The origin of this carbon-isotope anomaly is interpreted to lie in significant changes to carbon fluxes potentially stemming from reduced run off, lowering the fertility of surface waters which in turn leads to lessened primary production and a negative δ13C shift. These data are comparable with carbonate carbon isotope records from other Tethyan margin sediments. Our integrated biostratigraphy and carbon isotope stratigraphy enable us to improve stratigraphic correlation and age determination of the examined strata. Therefore, this study of the Komló Calcareous Marl Formation confirms that the existing carbon isotope curves serve as a global standard for Aalenian-Bathonian δ13C variation.

Tectonic setting of Jurassic basins in Central Mongolia: Insights from the geochemistry of Tsagaan-Ovoo oil shale

NASA Astrophysics Data System (ADS)

Erdenetsogt, B. O.; Hong, S. K.; Choi, J.; Odgerel, N.; Lee, I.; Ichinnorov, N.; Tsolmon, G.; Munkhnasan, B.

2017-12-01

Tsagaan-Ovoo syncline hosting Lower-Middle Jurassic oil shale is a part of Saikhan-Ovoo the largest Jurassic sedimentary basin in Central Mongolia. It is generally accepted that early Mesozoic basins are foreland basins. In total, 18 oil shale samples were collected from an open-pit mine. The contents of organic carbon, and total nitrogen and their isotopic compositions as well as major element concentrations were analyzed. The average TOC content is 12.4±1.2 %, indicating excellent source rock potential. C/N ratios show an average of 30.0±1.2, suggesting terrestrial OM. The average value of δ15N is +3.9±0.2‰, while that of δ13Corg is -25.7±0.1‰. The isotopic compositions argue for OM derived dominantly from land plant. Moreover, changes in δ15N values of analyzed samples reflect variations in algal OM concentration of oil shale. The lowest δ15N value (+2.5‰) was obtained from base section, representing the highest amount of terrestrial OM, whereas higher δ15N values (up to +5.2‰) are recorded at top section, reflecting increased amount of algal OM. On the other hand, changes in δ15N value may also represent changes in redox state of water column in paleolake. The oil shale at bottom of section with low δ15N value was accumulated under oxic condition, when the delivery of land plant OM was high. With increase in subsidence rate through time, lake was deepened and water column was depleted in oxygen probably due to extensive phytoplankton growth, which results increase in algae derived OM contents as well as bulk δ15N of oil shale. The average value of CAI for Tsagan-Ovoo oil shale is 81.6±1.3, reflecting intensive weathering in the source area. The plotted data on A-CN-K diagram displays that oil shale was sourced mainly from Early Permian granodiorite and diorite, which are widely distributed around Tsagaan-Ovoo syncline. To infer tectonic setting, two multi-dimensional discrimination diagrams were used. The results suggest that the tectonic

Nitrogen isotope and trace metal analyses from the Mingolsheim core (Germany): Evidence for redox variations across the Triassic-Jurassic boundary

NASA Astrophysics Data System (ADS)

Quan, Tracy M.; van de Schootbrugge, Bas; Field, M. Paul; Rosenthal, Yair; Falkowski, Paul G.

2008-06-01

The Triassic-Jurassic (T-J) boundary was one of the largest but least understood mass extinction events in the Phanerozoic. We measured bulk organic nitrogen and carbon isotopes and trace metal concentrations from a core near Mingolsheim (Germany) to infer paleoenvironmental conditions associated with this event. Poorly fossiliferous claystones across the boundary have relatively low δ15N values and low concentrations of redox-sensitive elements, characteristic of an oxic environment with significant terrestrial input. The Early Jurassic features enrichment in δ15N coincident with high redox-sensitive element concentrations, indicating an increase in water column denitrification and decreased oxygen concentrations. These redox state variations are concordant with shifts in abundance and species composition in terrestrial and marine microflora. We propose that the mass extinction at the T-J boundary was caused by a series of events resulting in a long period of stratification, deep-water hypoxia, and denitrification in this region of the Tethys Ocean basin.

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.

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…

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, J.D.L.; Vallier, T.; Stanley, G.D. Jr.

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 unlikemore » 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.« less

Tracing biosignatures from the Recent to the Jurassic in sabkha-associated microbial mats

NASA Astrophysics Data System (ADS)

van der Land, Cees; Dutton, Kirsten; Andrade, Luiza; Paul, Andreas; Sherry, Angela; Fender, Tom; Hewett, Guy; Jones, Martin; Lokier, Stephen W.; Head, Ian M.

2017-04-01

Microbial mat ecosystems have been operating at the sediment-fluid interface for over 3400 million years, influencing the flux, transformation and preservation of carbon from the biosphere to the physical environment. These ecosystems are excellent recorders of rapid and profound changes in earth surface environments and biota as they often survive crisis-induced extreme paleoenvironmental conditions. Their biosignatures, captured in the preserved organic matter and the biominerals that form the microbialite rock, constitute a significant tool in understanding geobiological processes and the interactions of the microbial communities with sediments and with the prevailing physical chemical parameters, as well as the environmental conditions at a local and global scale. Nevertheless, the exact pathways of diagenetic organic matter transformation and early-lithification, essential for the accretion and preservation in the geological record as microbialites, are not well understood. The Abu Dhabi coastal sabkha system contains a vast microbial mat belt that is dominated by continuous polygonal and internally-laminated microbial mats across the upper and middle intertidal zones. This modern system is believed to be the best analogue for the Upper Jurassic Arab Formation, which is both a prolific hydrocarbon reservoir and source rock facies in the United Arab Emirates and in neighbouring countries. In order to characterise the processes that lead to the formation of microbialites we investigated the modern and Jurassic system using a multidisciplinary approach, including growth of field-sampled microbial mats under controlled conditions in the laboratory and field-based analysis of microbial communities, mat mineralogy and organic biomarker analysis. In this study, we focus on hydrocarbon biomarker data obtained from the surface of microbial mats actively growing in the intertidal zone of the modern system. By comparing these findings to data obtained from recently

Stratigraphy and macrofauna of the Lower Jurassic (Toarcian) Marrat Formation, central Saudi Arabia

NASA Astrophysics Data System (ADS)

El-Sorogy, Abdelbaset S.; Gameil, Mohamed; Youssef, Mohamed; Al-Kahtany, Khaled M.

2017-10-01

The stratigraphy and macrofaunal content of the Lower Jurassic (Toarcian) Marrat Formation was studied at Khashm adh Dhibi, central Saudi Arabia. The studied succession is dominated by limestones and dolomites, with subordinate occurrences of sandstones, siltstones and claystones. The formation is highly fossiliferous with brachiopods, gastropods, bivalves, ammonites and echinoids, particularly the lower and upper members. Twenty nine species are identified, they include 7 species of brachiopods, 8 gastropods, 8 bivalves, 4 ammonites and 2 echinoids. Many of the identified fauna are correlated with Jurassic equivalents in Jordan, Italy, Morocco, Egypt and India. Three gastropod species: Globularia subumbilicata, Ampullospira sp., Purpuroidea peristriata and seven bivalve species: Palaeonucula lateralis, Chlamys (Radulopecten) fibrosa, Eligmus weiri, E.integer, E. asiaticus, Musculus somaliensis and Pholadomya orientalis were recognized for the first time in the Lower Jurassic deposits of Saudi Arabia.

The Tunisian Jurassic aquifer in the North African Sahara aquifer system: information derived from two-dimensional seismic reflection and well logs

NASA Astrophysics Data System (ADS)

Ben Lasmar, Rafika; Guellala, Rihab; Garrach, Mohamed; Mahroug, Ali; Sarsar Naouali, Benen; Inoubli, Mohamed Hédi

2017-12-01

Southern Tunisia is an arid area where socio-economic activities are dependent on groundwater resources. The presented study aims to better characterize the Jurassic aquifer based on geological and geophysical data, with a view to develop a rational exploitation program. Well logs are used to precisely determine the position and composition of the known Jurassic aquifer layers and to identify others able to produce good quality water. The logs show that limestones, sandstones and dolomites of the Krachoua, Techout and Foum Tataouine formations are the main Jurassic aquifers. Sixty-eight seismic-reflection sections are integrated within this study. The interpolation between the interpreted sections leads to the construction of isochronous isopach maps and geoseismic sections, and their analysis finds that compressive and extensive tectonic deformations have influenced the Jurassic aquifer geometry. The Hercynian orogeny phase manifestation is remarkable in that there are several stratigraphic gaps in the Jurassic sequence. The E-W, NW-SE, and NNW-SSE accidents, reactivated in normal faults since the Permian to Lower Cretaceous epochs, have generated the structures found in the Jurassic series, such as subsided and raised blocks. Their syn-sedimentary activity has controlled the thickness and facies of these series. The Cretaceous, Tortonian and Post-Villafranchian compressions are responsible for the Jurassic-deposits folding in some localities. The highlighted tectonic and sedimentary events have an important impact on the Jurassic aquifer function by favoring the Jurassic aquifer interconnections and their connections with the Triassic and Cretaceous permeable series.

Petrographic and geochemical characterization of the Triassic and Jurassic magmatic and volcanic rocks of southeastern Ecuador

NASA Astrophysics Data System (ADS)

Villares, Fabián; Eguez, Arturo; Yanez, Ernesto

2014-05-01

Formely, the subandean zone in the southeastern Ecuador involved large volcanic and magmatic rocks included in the Misahualli Formation and Zamora batholith, both as expression of the Jurassic cal-alcaline volcanic arc. The aim of the project carried out by the INIGEMM (Instituto Nacional de Investigación Geológico Minero Metalúrgico) was discriminate the volcanic products including a continuous set going from basalts to ryolithes and volcanoclastic rocks. Geochemical characterization was done using representative 16 whole - rock chemical analysis. The oldest rocks of the investigated area called Pachicutza Unit, include greenish to black, massive basalts and basaltic andesites, locally showing pillows structures. The texture is aphanitic to microporphyritic with slight crystal growth of plagioclase and pyroxenes. The Unit include also local pyroclastic breccias and tuffs showing variable skarnification related to the intrusion of the jurassic Zamora Batholith. Two samples of basalts show tholeiitic affinity, corresponding to an N- MORB, probably representing an early stage in opening of a regional Triassic rift reported since Colombia to Peru in the Andes. These geochemical characteristics are similar to the amphibolites of Monte Olivo Unit in the Real Cordillera. The Jurassic large volcanic assembly of the Misahualli Formation was also differenciated. Basal volcanics include green, subporphyritic andesites and volcanic breccias possibly generated at an early stage of the volcanic arc, caused by a change of extensive to compressive regime. Continental volcano sedimentary and sedimentary rock were discriminate as Nueva Esperanza and Suarez Units, respectively. The volcanosedimentary sequence include massive to laminate tuffs and tuffites of intermediate composition. The sediments of the Suarez Unit include dominant conglomerats and sandstones of fluvial domain. The regional volcanic sequence is completed by the Las Peñas Unit that includes aphanitic to

Emission factors of fine particulate matter, organic and elemental carbon, carbon monoxide, and carbon dioxide for four solid fuels commonly used in residential heating by the U.S. Navajo Nation.

PubMed

Champion, Wyatt M; Connors, Lea; Montoya, Lupita D

2017-09-01

Most homes in the Navajo Nation use wood as their primary heating fuel, often in combination with locally mined coal. Previous studies observed health effects linked to this solid-fuel use in several Navajo communities. Emission factors (EFs) for common fuels used by the Navajo have not been reported using a relevant stove type. In this study, two softwoods (ponderosa pine and Utah juniper) and two high-volatile bituminous coals (Black Mesa and Fruitland) were tested with an in-use residential conventional wood stove (homestove) using a modified American Society for Testing and Materials/U.S. Environmental Protection Agency (ASTM/EPA) protocol. Filter sampling quantified PM 2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) and organic (OC) and elemental (EC) carbon in the emissions. Real-time monitoring quantified carbon monoxide (CO), carbon dioxide (CO 2 ), and total suspended particles (TSP). EFs for these air pollutants were developed and normalized to both fuel mass and energy consumed. In general, coal had significantly higher mass EFs than wood for all pollutants studied. In particular, coal emitted, on average, 10 times more PM 2.5 than wood on a mass basis, and 2.4 times more on an energy basis. The EFs developed here were based on fuel types, stove design, and operating protocols relevant to the Navajo Nation, but they could be useful to other Native Nations with similar practices, such as the nearby Hopi Nation. Indoor wood and coal combustion is an important contributor to public health burdens in the Navajo Nation. Currently, there exist no emission factors representative of Navajo homestoves, fuels, and practices. This study developed emission factors for PM 2.5 , OC, EC, CO, and CO 2 using a representative Navajo homestove. These emission factors may be utilized in regional-, national-, and global-scale health and environmental models. Additionally, the protocols developed and results presented here may inform on-going stove design of

The occurrence of a shallow-water Ammobaculoides assemblage in the Middle Jurassic (Bajocian) Dhruma Formation of Central Saudi Arabia

NASA Astrophysics Data System (ADS)

Kaminski, Michael A.; Hammad Malik, Muhammad; Setoyama, Eiichi

2018-01-01

We report the occurrence of an Ammobaculoides-dominated assemblage in the lowermost member of the Middle Jurassic Dhruma Formation exposed west of Riyadh, Saudi Arabia. The new species Ammobaculoides dhrumaensis n.sp. is described from the green shale of the D1 unit (also known as the Balum Member) of the Dhruma Formation, which has been assigned an early Bajocian age based on ammonites. Our new finding constitutes the oldest reported worldwide occurrence of the agglutinated foraminiferal genus Ammobaculoides Plummer, 1932.

A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum

PubMed Central

Pol, Diego; Garrido, Alberto; Cerda, Ignacio A.

2011-01-01

Background The origin of sauropod dinosaurs is one of the major landmarks of dinosaur evolution but is still poorly understood. This drastic transformation involved major skeletal modifications, including a shift from the small and gracile condition of primitive sauropodomorphs to the gigantic and quadrupedal condition of sauropods. Recent findings in the Late Triassic–Early Jurassic of Gondwana provide critical evidence to understand the origin and early evolution of sauropods. Methodology/Principal Findings A new sauropodomorph dinosaur, Leonerasaurus taquetrensis gen. et sp. nov., is described from the Las Leoneras Formation of Central Patagonia (Argentina). The new taxon is diagnosed by the presence of anterior unserrated teeth with a low spoon-shaped crown, amphicoelous and acamerate vertebral centra, four sacral vertebrae, and humeral deltopectoral crest low and medially deflected along its distal half. The phylogenetic analysis depicts Leonerasaurus as one of the closest outgroups of Sauropoda, being the sister taxon of a clade of large bodied taxa composed of Melanorosaurus and Sauropoda. Conclusions/Significance The dental and postcranial anatomy of Leonerasaurus supports its close affinities with basal sauropods. Despite the small size and plesiomorphic skeletal anatomy of Leonerasaurus, the four vertebrae that compose its sacrum resemble that of the large-bodied primitive sauropods. This shows that the appearance of the sauropod-type of sacrum predated the marked increase in body size that characterizes the origins of sauropods, rejecting a causal explanation and evolutionary linkage between this sacral configuration and body size. Alternative phylogenetic placements of Leonerasaurus as a basal anchisaurian imply a convergent acquisition of the sauropod-type sacrum in the new small-bodied taxon, also rejecting an evolutionary dependence of sacral configuration and body size in sauropodomorphs. This and other recent discoveries are showing that the

Mantophasmatodea now in the Jurassic

NASA Astrophysics Data System (ADS)

Huang, Di-Ying; Nel, André; Zompro, Oliver; Waller, Alain

2008-10-01

The Mantophasmatodea is the most recently discovered insect order. The fossil records of all other ‘polyneopteran’ orders extend far in the past, but the current absence of pre-Cenozoic fossils of the Mantophasmatodea contradicts a long evolutionary history, which has to be assumed from the morphological distinctness of the group. In this paper, we report the first Mesozoic evidence of a mantophasmatodean from the Middle Jurassic of Daohugou, Inner Mongolia, China. Furthermore, the new fossil shares apomorphic characters with Cenozoic and recent Mantophasmatodea, suggesting a longer evolutionary history of this order.

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

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…

Development of a decision aid for energy resource management for the Navajo Nation incorporating environmental cultural values

NASA Astrophysics Data System (ADS)

Necefer, Len Edward

Decision-making surrounding pathways of future energy resource management are complexity and requires balancing tradeoffs of multiple environmental, social, economic, and technical outcomes. Technical decision aid can provide a framework for informed decision making, allowing individuals to better understand the tradeoff between resources, technology, energy services, and prices. While technical decision aid have made significant advances in evaluating these quantitative aspects of energy planning and performance, they have not been designed to incorporate human factors, such as preferences and behavior that are informed by cultural values. Incorporating cultural values into decision tools can provide not only an improved decision framework for the Navajo Nation, but also generate new insights on how these perspective can improve decision making on energy resources. Ensuring these aids are a cultural fit for each context has the potential to increase trust and promote understanding of the tradeoffs involved in energy resource management. In this dissertation I present the development of a technical tool that explicitly addresses cultural and spiritual values and experimentally assesses their influence on the preferences and decision making of Navajo citizens. Chapter 2 describes the results of a public elicitation effort to gather information about stakeholder views and concerns related to energy development in the Navajo Nation in order to develop a larger sample survey and a decision-support tool that links techno-economic energy models with sociocultural attributes. Chapter 3 details the methods of developing the energy decision aid and its underlying assumptions for alternative energy projects and their impacts. This tool also provides an alternative to economic valuation of cultural impacts based upon an ordinal index tied to environmental impacts. Chapter 4 details the the influence of various cultural, environmental, and economic outcome information provided

The Record of Meteorite Infall During the Jurassic as Derived from Chrome-Spinel Grains

NASA Astrophysics Data System (ADS)

Caplan, C.; Huss, G. R.; Schmitz, B.; Nagashima, K.

2017-12-01

We study sediment-dispersed chrome-spinels in the stratigraphic record to determine how the types and amounts of meteorites falling to Earth have changed over time. The parent meteorite type of chrome-spinel grains can be determined using characteristic elemental and O-isotope compositions. In this study, we present data on grains from the Jurassic period ( 160 Ma). The Jurassic was chosen because of the possibility of discovering remnants from the breakup of the Baptistina asteroid family estimated to have occurred 160 Ma (+30, -20 Myr) (Bottke et al., 2007). Chrome-spinel grains derived from 400 kg of condensed limestone near Carcabuey, Spain were measured for their chemical compositions by electron microprobe, and their O-isotope compositions were measured by ion microprobe at the University of Hawai'i. Initial results show that 43% of the grains come from ordinary chondrites (OCs) and 18% from known types of achondrites. The remaining grains are extraterrestrial, as shown by their O-isotopes, but have not yet been classified. Some may represent material that is not currently falling on Earth. Meteorites falling on Earth today are 90.6% OCs and 7.1% achondrites. The Jurassic samples show a lower percentage of chrome-spinels from OCs (even though OCs are chrome-spinel rich). Other time periods also show meteorite abundances that are different than today. About 466 Ma there was an overwhelming influx of L-chondritic material (>99% of infalling material), due to the breakup of the L-chondrite parent body (Schmitz et al., 2001). One million years prior to the breakup, 56% of the infalling meteorites were OCs and 44% were achondrites (Heck et al., 2017). A new study suggests that 80% of the material falling in the Early Cretaceous (145-133 Ma) were from OCs and 10% were from achondrites (Schmitz et al., 2017). With just a few windows into Earth's past, we are already seeing significant changes in the mixture of materials that have fallen to Earth throughout time.

Coping and Responses to Stress in Navajo Adolescents: Psychometric Properties of the Responses to Stress Questionnaire

ERIC Educational Resources Information Center

Wadsworth, Martha E.; Rieckmann, Traci; Benson, Molly A.; Compas, Bruce E.

2004-01-01

This study tested the factor structure of coping and stress responses in Navajo adolescents and examined the reliability and validity of the Responses to Stress Questionnaire (RSQ; Connor-Smith, Compas, Wadsworth, Thomsen, & Saltzman, 2000) with this population. Confirmatory factor analyses revealed that a correlated five-factor model of…

25 CFR 161.713 - How will BIA determine the amount of damages to Navajo Partitioned Lands?

Code of Federal Regulations, 2012 CFR

2012-04-01

... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Penalties, Damages, and Costs § 161.713... damages by considering the costs of rehabilitation and re-vegetation, loss of future revenue, loss of... will determine the value of forage or crops consumed or destroyed based upon the average rate received...

25 CFR 161.713 - How will BIA determine the amount of damages to Navajo Partitioned Lands?

Code of Federal Regulations, 2011 CFR

2011-04-01

... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Penalties, Damages, and Costs § 161.713... damages by considering the costs of rehabilitation and re-vegetation, loss of future revenue, loss of... will determine the value of forage or crops consumed or destroyed based upon the average rate received...

25 CFR 161.713 - How will BIA determine the amount of damages to Navajo Partitioned Lands?

Code of Federal Regulations, 2014 CFR

2014-04-01

... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Penalties, Damages, and Costs § 161.713... damages by considering the costs of rehabilitation and re-vegetation, loss of future revenue, loss of... will determine the value of forage or crops consumed or destroyed based upon the average rate received...

25 CFR 161.713 - How will BIA determine the amount of damages to Navajo Partitioned Lands?

Code of Federal Regulations, 2013 CFR

2013-04-01

... AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Penalties, Damages, and Costs § 161.713... damages by considering the costs of rehabilitation and re-vegetation, loss of future revenue, loss of... will determine the value of forage or crops consumed or destroyed based upon the average rate received...

Climatic and palaeoceanographic changes during the Pliensbachian (Early Jurassic) inferred from clay mineralogy and stable isotope (C-O) geochemistry (NW Europe)

NASA Astrophysics Data System (ADS)

Bougeault, Cédric; Pellenard, Pierre; Deconinck, Jean-François; Hesselbo, Stephen P.; Dommergues, Jean-Louis; Bruneau, Ludovic; Cocquerez, Théophile; Laffont, Rémi; Huret, Emilia; Thibault, Nicolas

2017-02-01

The Early Jurassic was broadly a greenhouse climate period that was punctuated by short warm and cold climatic events, positive and negative excursions of carbon isotopes, and episodes of enhanced organic matter burial. Clay minerals from Pliensbachian sediments recovered from two boreholes in the Paris Basin, are used here as proxies of detrital supplies, runoff conditions, and palaeoceanographic changes. The combined use of these minerals with stable isotope data (C-O) from bulk carbonates and organic matter allows palaeoclimatic reconstructions to be refined for the Pliensbachian. Kaolinite/illite ratio is discussed as a reliable proxy of the hydrological cycle and runoff from landmasses. Three periods of enhanced runoff are recognised within the Pliensbachian. The first one at the Sinemurian-Pliensbachian transition shows a significant increase of kaolinite concomitant with the negative carbon isotope excursion at the so-called Sinemurian Pliensbachian Boundary Event (SPBE). The Early/Late Pliensbachian transition was also characterised by more humid conditions. This warm interval is associated with a major change in oceanic circulation during the Davoei Zone, likely triggered by sea-level rise; the newly created palaeogeography, notably the flooding of the London-Brabant Massif, allowed boreal detrital supplies, including kaolinite and chlorite, to be exported to the Paris Basin. The last event of enhanced runoff occurred during the late Pliensbachian (Subnodosus Subzone of the Margaritatus Zone), which occurred also during a warm period, favouring organic matter production and preservation. Our study highlights the major role of the London Brabant Massif in influencing oceanic circulation of the NW European area, as a topographic barrier (emerged lands) during periods of lowstand sea-level and its flooding during period of high sea-level. This massif was the unique source of smectite in the Paris Basin. Two episodes of smectite-rich sedimentation ('smectite

Post-Jurassic tectonic evolution of Southeast Asia

NASA Astrophysics Data System (ADS)

Zahirovic, Sabin; Seton, Maria; Dietmar Müller, R.; Flament, Nicolas

2014-05-01

The accretionary growth of Asia, linked to long-term convergence between Eurasia, Gondwana-derived blocks and the Pacific, resulted in a mosaic of terranes for which conflicting tectonic interpretations exist. Here, we propose solutions to a number of controversies related to the evolution of Sundaland through a synthesis of published geological data and plate reconstructions that reconcile both geological and geophysical constraints with plate driving forces. We propose that West Sulawesi, East Java and easternmost Borneo rifted from northern Gondwana in the latest Jurassic, collided with an intra-oceanic arc at ~115 Ma and subsequently sutured to Sundaland by 80 Ma. Although recent models argue that the Southwest Borneo core accreted to Sundaland at this time, we use volcanic and biogeographic constraints to show that the core of Borneo was on the Asian margin since at least the mid Jurassic. This northward transfer of Gondwana-derived continental fragments required a convergent plate boundary in the easternmost Tethys that we propose gave rise to the Philippine Archipelago based on the formation of latest Jurassic-Early Cretaceous supra-subduction zone ophiolites on Halmahera, Obi Island and Luzon. The Late Cretaceous marks the shift from Andean-style subduction to back-arc opening on the east Asian margin. Arc volcanism along South China ceased by ~60 Ma due to the rollback of the Izanagi slab, leading to the oceanward migration of the volcanic arc and the opening of the Proto South China Sea (PSCS). We use the Apennines-Tyrrhenian system in the Mediterranean as an analogue to model this back-arc. Continued rollback detaches South Palawan, Mindoro and the Semitau continental blocks from the stable east Asian margin and transfers them onto Sundaland in the Eocene to produce the Sarawak Orogeny. The extrusion of Indochina and subduction polarity reversal along northern Borneo opens the South China Sea and transfers the Dangerous Grounds-Reed Bank southward to

Paleocurrents of the Middle-Upper Jurassic strata in the Paradox Basin, Colorado, inferred from anisotropy of magnetic susceptibility (AMS)

NASA Astrophysics Data System (ADS)

Ejembi, J. I.; Ferre, E. C.; Potter-McIntyre, S. L.

2017-12-01

The Middle-Upper Jurassic sedimentary strata in the southwestern Colorado Plateau recorded pervasive eolian to fluvio-lacustrine deposition in the Paradox Basin. While paleocurrents preserved in the Entrada Sandstone, an eolian deposition in the Middle Jurassic, has been well constrained and show a northwesterly to northeasterly migration of ergs from the south onto the Colorado Plateau, there is yet no clear resolution of the paleocurrents preserved in the Wanakah Formation and Tidwell Member of the Morrison Formation, both of which are important sedimentary sequences in the paleogeographic framework of the Colorado Plateau. New U-Pb detrital zircon geochronology of sandstones from these sequences suggests that an abrupt change in provenance occurred in the early Late Jurassic, with sediments largely sourced from eroding highlands in central Colorado. We measured the anisotropy of magnetic susceptibility (AMS) of sediments in oriented sandstone samples from these three successive sequences; first, to determine the paleocurrents from the orientations of the AMS fabrics in order to delineate the source area and sediments dispersal pattern and second, to determine the depositional mechanisms of the sediments. Preliminary AMS data from two study sites show consistency and clustering of the AMS axes in all the sedimentary sequences. The orientations of the Kmin - Kint planes in the Entrada Sandstone sample point to a NNE-NNW paleocurrent directions, which is in agreement with earlier studies. The orientations of the Kmin - Kint planes in the Wanakah Formation and Tidwell Member samples show W-SW trending paleocurrent directions, corroborating our hypothesis of a shift in provenance to the eroding Ancestral Front Range Mountain, located northeast of the Paradox Basin, during the Late Jurassic. Isothermal remanence magnetization (IRM) of the samples indicate that the primary AMS carriers are detrital, syndepositional ferromagnetic minerals. Thus, we contend that AMS can

Environmental drivers of crocodyliform extinction across the Jurassic/Cretaceous transition

PubMed Central

Mannion, Philip D.; Upchurch, Paul

2016-01-01

Crocodyliforms have a much richer evolutionary history than represented by their extant descendants, including several independent marine and terrestrial radiations during the Mesozoic. However, heterogeneous sampling of their fossil record has obscured their macroevolutionary dynamics, and obfuscated attempts to reconcile external drivers of these patterns. Here, we present a comprehensive analysis of crocodyliform biodiversity through the Jurassic/Cretaceous (J/K) transition using subsampling and phylogenetic approaches and apply maximum-likelihood methods to fit models of extrinsic variables to assess what mediated these patterns. A combination of fluctuations in sea-level and episodic perturbations to the carbon and sulfur cycles was primarily responsible for both a marine and non-marine crocodyliform biodiversity decline through the J/K boundary, primarily documented in Europe. This was tracked by high extinction rates at the boundary and suppressed origination rates throughout the Early Cretaceous. The diversification of Eusuchia and Notosuchia likely emanated from the easing of ecological pressure resulting from the biodiversity decline, which also culminated in the extinction of the marine thalattosuchians in the late Early Cretaceous. Through application of rigorous techniques for estimating biodiversity, our results demonstrate that it is possible to tease apart the complex array of controls on diversification patterns in major archosaur clades. PMID:26962137

Discovery of Jurassic ammonite-bearing series in Jebel Bou Hedma (South-Central Tunisian Atlas): Implications for stratigraphic correlations and paleogeographic reconstruction

NASA Astrophysics Data System (ADS)

Bahrouni, Néjib; Houla, Yassine; Soussi, Mohamed; Boughdiri, Mabrouk; Ali, Walid Ben; Nasri, Ahmed; Bouaziz, Samir

2016-01-01

Recent geological mapping undertaken in the Southern-Central Atlas of Tunisia led to the discovery of Jurassic ammonite-bearing series in the Jebel Bou Hedma E-W anticline structure. These series represent the Southernmost Jurassic rocks ever documented in the outcrops of the Tunisian Atlas. These series which outcrop in a transitional zone between the Southern Tunisian Atlas and the Chott basin offer a valuable benchmark for new stratigraphic correlation with the well-known Jurassic series of the North-South Axis of Central Tunisia and also with the Jurassic subsurface successions transected by petroleum wells in the study area. The preliminary investigations allowed the identification, within the most complete section outcropping in the center of the structure, of numerous useful biochronological and sedimentological markers helping in the establishment of an updated Jurassic stratigraphic framework chart of South-Western Tunisia. Additionally, the Late Jurassic succession documents syn-sedimentary features such as slumping, erosion and reworking of sediments and ammonite faunas that can be considered as strong witnesses of an important geodynamic event around the Jurassic-Cretaceous boundary. These stratigraphic and geodynamic new data make of the Jurassic of Jebel Bou Hedma a key succession for stratigraphic correlation attempt between Atlas Tunisian series and those currently buried in the Chott basin or outcropping in the Saharan platform. Furthermore, the several rich-ammonite identified horizons within the Middle and Upper Jurassic series constitute reliable time lines that can be useful for both paleogeographic and geodynamic reconstructions of this part of the North African Tethyan margin but also in the refinement of the potential migration routes for ammonite populations from the Maghrebian Southern Tethys to Arabia.

A food store-based environmental intervention is associated with reduced BMI and improved psychosocial factors and food-related behaviors on the Navajo nation.

PubMed

Gittelsohn, Joel; Kim, Elizabeth M; He, Siran; Pardilla, Marla

2013-09-01

The prevalence of obesity is significantly higher among American Indians (AIs) and is associated with increased rates of diabetes, hypertension, and cardiovascular disease. We implemented a 14-mo intervention trial (Navajo Healthy Stores) on the Navajo Nation that sought to increase availability of healthier foods in local food stores and to promote these foods at the point of purchase and through community media. We divided the Navajo Nation into 10 store regions, half of which were randomized to intervention and half to comparison. We evaluated the program by using a pre-post sample of systematically sampled adult Navajo consumers (baseline, n = 276; postintervention, n = 145). Intervention impact was examined by analyzing pre-post differences by intervention group and by intervention exposure level. When intervention and comparison groups were compared, only body mass index (BMI) showed a trend toward impact of the intervention (P = 0.06). However, greater exposure to the intervention was associated with significantly reduced BMI (P ≤ 0.05) and improved healthy food intentions (P ≤ 0.01), healthy cooking methods (P ≤ 0.05), and healthy food getting (P ≤ 0.01). With increasing exposure, the odds of improving overweight or obese status was 5.02 (95% CI: 1.48, 16.99; P ≤ 0.01) times the odds of maintaining or worsening overweight or obese status. In summary, a food store intervention was associated with reduced overweight/obesity and improved obesity-related psychosocial and behavioral factors among those persons most exposed to the intervention on an AI reservation.

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

The Braincase and Neurosensory Anatomy of an Early Jurassic Marine Crocodylomorph: Implications for Crocodylian Sinus Evolution and Sensory Transitions.

PubMed

Brusatte, Stephen L; Muir, Amy; Young, Mark T; Walsh, Stig; Steel, Lorna; Witmer, Lawrence M

2016-11-01

Modern crocodylians are a morphologically conservative group, but extinct relatives (crocodylomorphs) experimented with a wide range of diets, behaviors, and body sizes. Among the most unusual of these fossil groups is the thalattosuchians, an assemblage of marine-dwellers that transitioned from semiaquatic species (teleosaurids and kin) into purely open-ocean forms (metriorhynchids) during the Jurassic and Cretaceous Periods (ca 191-125 million years ago). Thalattosuchians can give insight into the origin of modern crocodylian morphologies and how anatomy and behavior change during a major evolutionary transition into a new habitat. Little is known, however, about their brains, sensory systems, cranial sinuses, and vasculature. We here describe the endocranial anatomy of a well-preserved specimen of the Jurassic semiaquatic teleosaurid Steneosaurus cf. gracilirostris using X-ray micro-CT. We find that this teleosaurid still had an ear well attuned to hear on land, but had developed large internal carotid and orbital arteries that likely supplied salt glands, previously thought to be present in only the fully pelagic metriorhynchids. There is no great gulf in endocranial anatomy between this teleosaurid and the metriorhynchids, and some of the features that later permitted metriorhynchids to invade the oceanic realm were apparently first developed in semiaquatic taxa. Compared to modern crocodylians, Steneosaurus cf. gracilirostris has a more limited set of pharyngotympanic sinuses, but it is unclear whether this relates to its aquatic habitat or represents the primitive condition of crocodylomorphs that was later elaborated. Anat Rec, 299:1511-1530, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Lessons Learned: Tribal Community Engagement, Remediation and Restoration of a Uranium Mine Tailings Site, Navajo Nation - 12484

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wadsworth, Donald K.; Hicks, Allison H.

2012-07-01

In May, 2011 New World Environmental Inc. was awarded a contract by the Navajo Nation Environmental Protection Agency to remediate an illegal radioactive waste disposal site located in the Navajo Nation. The initial scope included the excavation and shipment of an estimated 3,000 cubic yards of Uranium mine tailings and associated industrial waste. In this instance Stakeholders were supportive of the project, remediation and restoration, yet the movement of residual radioactive materials through tribal communities was a controversial issue. Other Stakeholder issues included site security, water sources for remediation activities, local residents' temporary re-location and care of livestock, right ofmore » way permissions and local workforce development. This presentation recaps the technical and non-technical issues encountered in the remediation and restoration the seven acre site and the outreach to surrounding communities. Cultural and equity issues resulting from historical problems associated with this and other sites in the immediate area and education and training. (authors)« less

Navajo Environmental Health Review by the National Environmental Health Association (Window Rock, Arizona, May 24-27, 1976).

ERIC Educational Resources Information Center

Navajo Health Authority, Window Rock, AZ.

The Indian Health Committee met with key staff of the Indian Health Service (IHS) Area Office to review the environmental health services provided on the Navajo Reservation and make recommendations for improvement or expansion of current programs, if needed. Recommendations were made regarding environmental health and institutional personnel,…

Perception, Cultural, and Technical Assessment of Heating Alternatives to Improve Indoor Air Quality on the Navajo Nation

EPA Science Inventory

It is estimated that 62 percent of households in the Navajo Nation use wood as their primary heating source, while 25 percent use gaseous fuels, 11 percent use electricity, and the remaining 2 percent use coal, kerosene, other fossil fuels, or solar energy. A 2010 study by the U....

Late Jurassic – early Cretaceous inversion of rift structures, and linkage of petroleum system elements across post-rift unconformity, U.S. Chukchi Shelf, arctic Alaska

USGS Publications Warehouse

Houseknecht, David W.; Connors, Christopher D.

2015-01-01

Oil-prone source rocks, reservoir-quality sandstone, migration pathways, and structural closure are linked intimately across the Jurassic unconformity, which reflects inversion. Thus, all these key petroleum systems elements were in place when Triassic source rocks entered the oil generation window during Cretaceous–Cenozoic stratigraphic burial.

Mothers' and fathers' involvement with school-age children's care and academic activities in Navajo Indian families.

PubMed

Hossain, Ziarat; Anziano, Michael C

2008-04-01

This exploratory study examined mothers' and fathers' reports of time involvement in their school-age children's care and academic activities. The study also explored the relationship between parents' socioeconomic status (SES) variables (age, education, income, work hours, and length of marriage) and their relative involvement with children. Mother and father dyads from 34 two-parent Navajo (Diné) Indian families with a second- or third-grade child participated in the study. Repeated measures analysis of variance showed that mothers invested significantly more time in children's care on demand and academic activities than fathers, but the differences in maternal and paternal perceptions of time involvement in routine care were not significant. The gender of the child did not influence the amount of time parents invested in children's care and academic activities. Mothers' involvement with children was not related to any of the SES variables. Fathers' involvement was significantly associated with work hours and length of marriage, and work hours produced significant interaction with fathers' involvement with children. Findings are discussed in light of gender role differences in parental involvement with children within Navajo families.

A Food Store–Based Environmental Intervention Is Associated with Reduced BMI and Improved Psychosocial Factors and Food-Related Behaviors on the Navajo Nation123

PubMed Central

Gittelsohn, Joel; Kim, Elizabeth M.; He, Siran; Pardilla, Marla

2013-01-01

The prevalence of obesity is significantly higher among American Indians (AIs) and is associated with increased rates of diabetes, hypertension, and cardiovascular disease. We implemented a 14-mo intervention trial (Navajo Healthy Stores) on the Navajo Nation that sought to increase availability of healthier foods in local food stores and to promote these foods at the point of purchase and through community media. We divided the Navajo Nation into 10 store regions, half of which were randomized to intervention and half to comparison. We evaluated the program by using a pre-post sample of systematically sampled adult Navajo consumers (baseline, n = 276; postintervention, n = 145). Intervention impact was examined by analyzing pre-post differences by intervention group and by intervention exposure level. When intervention and comparison groups were compared, only body mass index (BMI) showed a trend toward impact of the intervention (P = 0.06). However, greater exposure to the intervention was associated with significantly reduced BMI (P ≤ 0.05) and improved healthy food intentions (P ≤ 0.01), healthy cooking methods (P ≤ 0.05), and healthy food getting (P ≤ 0.01). With increasing exposure, the odds of improving overweight or obese status was 5.02 (95% CI: 1.48, 16.99; P ≤ 0.01) times the odds of maintaining or worsening overweight or obese status. In summary, a food store intervention was associated with reduced overweight/obesity and improved obesity-related psychosocial and behavioral factors among those persons most exposed to the intervention on an AI reservation. PMID:23864511

Pre-breakup geology of the Gulf of Mexico-Caribbean: Its relation to Triassic and Jurassic rift systems of the region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bartok, P.

1993-02-01

A review of the pre-breakup geology of west-central Pangea, comprised of northern South America, Gulf of Mexico and West Africa, combined with a study of the Mesozoic rift trends of the region confirms a relation between the rift systems and the underlying older grain of deformation. The pre-breakup analysis focuses attention on the Precambrian, Early Paleozoic and Late Paleozoic tectonic events affecting the region and assumes a Pindell fit. Two Late Precambrian orogenic belts are observed in the west central Pangea. Along the northern South American margin and Yucatan a paleo northeast trending Pan-African aged fold belt is documented. Amore » second system is observed along West Africa extending from the High Atlas to the Mauritanides and Rockelides. During the Late Paleozoic, renewed orogenic activity, associated with the Gondwana/Laurentia suture, affected large segments of west central Pangea. The general trend of the system is northeast-southwest and essentially parallels the Gyayana Shield, West African, and eastern North American cratons. Mesozoic rifting closely followed either the Precambrian trends or the Late Paleozoic orogenic belt. The Triassic component focuses along the western portions of the Gulf of Mexico continuing into eastern Mexico and western South America. The Jurassic rift trend followed along the separation between Yucatan and northern South America. At Lake Maracaibo the Jurassic rift system eventually overlaps the Triassic rifts. The Jurassic rift resulted in the [open quotes]Hispanic Corridor[close quotes] that permitted Tethyan and Pacific marine faunas to mix at a time when the Gulf of Mexico underwent continental sedimentation.« less

A New Look at the Magnetostratigraphy and Paleomagnetism of the Upper Triassic to Lower Jurassic Moenave Formation, St. George Area, Southwestern Utah.

NASA Astrophysics Data System (ADS)

Donohoo-Hurley, L. L.; Geissman, J. W.; Lucas, S. G.; Roy, M.

2006-12-01

Paleomagnetic data from rocks exposed on and off the Colorado Plateau provide poles that young westward during the Late Triassic (to about 52^{O} E longitude) and young eastward during the Early Jurassic. This pattern has been used to posit the existence of a J-1 cusp in the North American APW path at the Triassic- Jurassic boundary (TJB), at about 199.6 Ma. Considerable debate has focused on the morphology and placement of the J-1 cusp due to poorly exposed and/or incompletely sampled sections, debates about the magnitude of Colorado Plateau rotation, and disagreements regarding stratigraphic relationships. Red beds of the Whitmore Point (~25 m of mostly lacustrine deposits) and Dinosaur Canyon (~55 m of hematitic fluvial sandstones and siltstones) members of the Moenave Formation (MF) are inferred to have been deposited across the TJB based on palynostratigraphy and vertebrate biostratigraphy. Two previously unsampled sections (Leeds and Warner Valley) of the MF are well exposed near St. George, Utah, and located in the transition zone that defines the western boundary of the Colorado Plateau. Preliminary data from samples collected from the Whitmore Point and Dinosaur Canyon members yield exclusively normal polarity magnetizations, which is consistent with previous studies and the normal polarity TJB magnetozone. Thermal demagnetization response suggests that the remanence is carried mainly in hematite. The degree of hematite pigmentation varies in both sections, and several Leeds sites show a weak overprint component that unblocks by 400^{O}-450^{O} C, with a higher unblocking temperature components, consistent with an Early Triassic Late Jurassic age that fully unblock around 670^{O}-680^{O} C. Individual beds (treated as specific sites) in part of the Dinosaur Canyon Member yield site mean directions with declinations between about 020 and 030, and may define the easternmost position (i.e. 60-50^{O} E latitude) of the NAMAPW path and thus the approximate the

Navajo Code Talker Joe Morris, Sr. shared insights from his time as a secret World War Two messenger

NASA Technical Reports Server (NTRS)

2002-01-01

Navajo Code Talker Joe Morris, Sr. shared insights from his time as a secret World War Two messenger with his audience at NASA's Dryden Flight Research Center on Nov. 26, 2002. NASA Dryden is located on Edwards Air Force Base in California's Mojave Desert.

Larval cases of caddisfly (Insecta: Trichoptera) affinity in Early Permian marine environments of Gondwana

NASA Astrophysics Data System (ADS)

Mouro, Lucas D.; Zatoń, Michał; Fernandes, Antonio C. S.; Waichel, Breno L.

2016-01-01

Caddisflies (Trichoptera) are small, cosmopolitan insects closely related to the Lepidoptera (moths and butterflies). Most caddisflies construct protective cases during their larval development. Although the earliest recognisable caddisflies date back to the early Mesozoic (Early and Middle Triassic), being particularly numerous and diverse during the Late Jurassic and Early Cretaceous, the first records of their larval case constructions are known exclusively from much younger, Early to Middle Jurassic non-marine deposits in the northern hemisphere. Here we present fossils from the Early Permian (Asselian-Sakmarian) marine deposits of Brazil which have strong morphological and compositional similarity to larval cases of caddisflies. If they are, which is very probable, these finds not only push back the fossil record of true caddisflies, but also indicate that their larvae constructed cases at the very beginning of their evolution in marine environments. Since modern caddisflies that construct larval cases in marine environments are only known from eastern Australia and New Zealand, we suggest that this marine ecology may have first evolved in western Gondwana during the Early Permian and later spread across southern Pangea.

Larval cases of caddisfly (Insecta: Trichoptera) affinity in Early Permian marine environments of Gondwana

PubMed Central

Mouro, Lucas D.; Zatoń, Michał; Fernandes, Antonio C.S.; Waichel, Breno L.

2016-01-01

Caddisflies (Trichoptera) are small, cosmopolitan insects closely related to the Lepidoptera (moths and butterflies). Most caddisflies construct protective cases during their larval development. Although the earliest recognisable caddisflies date back to the early Mesozoic (Early and Middle Triassic), being particularly numerous and diverse during the Late Jurassic and Early Cretaceous, the first records of their larval case constructions are known exclusively from much younger, Early to Middle Jurassic non-marine deposits in the northern hemisphere. Here we present fossils from the Early Permian (Asselian–Sakmarian) marine deposits of Brazil which have strong morphological and compositional similarity to larval cases of caddisflies. If they are, which is very probable, these finds not only push back the fossil record of true caddisflies, but also indicate that their larvae constructed cases at the very beginning of their evolution in marine environments. Since modern caddisflies that construct larval cases in marine environments are only known from eastern Australia and New Zealand, we suggest that this marine ecology may have first evolved in western Gondwana during the Early Permian and later spread across southern Pangea. PMID:26765261

Larval cases of caddisfly (Insecta: Trichoptera) affinity in Early Permian marine environments of Gondwana.

PubMed

Mouro, Lucas D; Zatoń, Michał; Fernandes, Antonio C S; Waichel, Breno L

2016-01-14

Caddisflies (Trichoptera) are small, cosmopolitan insects closely related to the Lepidoptera (moths and butterflies). Most caddisflies construct protective cases during their larval development. Although the earliest recognisable caddisflies date back to the early Mesozoic (Early and Middle Triassic), being particularly numerous and diverse during the Late Jurassic and Early Cretaceous, the first records of their larval case constructions are known exclusively from much younger, Early to Middle Jurassic non-marine deposits in the northern hemisphere. Here we present fossils from the Early Permian (Asselian-Sakmarian) marine deposits of Brazil which have strong morphological and compositional similarity to larval cases of caddisflies. If they are, which is very probable, these finds not only push back the fossil record of true caddisflies, but also indicate that their larvae constructed cases at the very beginning of their evolution in marine environments. Since modern caddisflies that construct larval cases in marine environments are only known from eastern Australia and New Zealand, we suggest that this marine ecology may have first evolved in western Gondwana during the Early Permian and later spread across southern Pangea.

Abandoned Uranium Mine (AUM) Trust Mine Points, Navajo Nation, 2016, US EPA Region 9

EPA Pesticide Factsheets

This GIS dataset contains point features that represent mines included in the Navajo Environmental Response Trust. This mine category also includes Priority mines. USEPA and NNEPA prioritized mines based on gamma radiation levels, proximity to homes and potential for water contamination identified in the preliminary assessments. Attributes include mine names, reclaimed status, links to US EPA AUM reports, and the region in which the mine is located. This dataset contains 19 features.

Maps showing ground-water conditions in the Hopi area, Coconino and Navajo counties, Arizona; 1977

USGS Publications Warehouse

Farrar, C.D.

1980-01-01

The Hop·; area includes about 3,200 mi2 in northeastern Arizona ~nd is mostly in the Navajo and Hopi Indian Reservations; about 400 mi of the area is south of the Navajo Indian Reservation boundary . Ground water occurs in several aquifers that are made up of one or more formations; the composite stratigraphic column indicates the relative position of the formations. The main sources of ground water are the Coconino aquifer, the Chinle Formation. the N and D aquifers, the Toreva and Bidahochi Formations, and the alluvium. The aquifers are separated by fine-grained rock units that inhibit the vertical movement of ground water.Ground-water development has been slight, and the water is used mainly for public, domestic, and livestock supplies. In 1977 about 425 acre-ft of ground water was withdrawn in the Hopi area. The amount of ground water withdrawn annually is small compared to the potential recharge from precipitation; therefore, water levels generally are not affected by pumping from wells.Because the ground-water system in the Hopi area has not been changed greatly by development, a large number of water-level measurements and water-quality data collected prior to 1977 are used in this report to show conditions in 1977. A few water-level measurements were made south of the Navajo Indian Reservation boundary in 1977. The hydrologic data on which these maps are based are available, fo~ the most part, ·in computer-printout form and may be consulted at.the Arizona Water Commission, 222 North Central Avenue, Suite 850, Phoenix, and at U.S. Geological Survey offices in: Federal Building, 301 West Congress Street, Tucson; Valley Center, Suite 1880, Phoenix; and 2255 North Gemini Drive, Building 3, Flagstaff. Material from which copies can be made at private expense is available at the Tucson, Phoenix, and Flagstaff offices of the U.S . Geological Survey.

Development and pilot evaluation of Native CREST-a Cancer Research Experience and Student Training program for Navajo undergraduate students.

PubMed

Hughes, Christine A; Bauer, Mark C; Horazdovsky, Bruce F; Garrison, Edward R; Patten, Christi A; Petersen, Wesley O; Bowman, Clarissa N; Vierkant, Robert A

2013-03-01

The Mayo Clinic Cancer Center and Diné College received funding for a 4-year collaborative P20 planning grant from the National Cancer Institute in 2006. The goal of the partnership was to increase Navajo undergraduates' interest in and commitment to biomedical coursework and careers, especially in cancer research. This paper describes the development, pilot testing, and evaluation of Native CREST (Cancer Research Experience and Student Training), a 10-week cancer research training program providing mentorship in a Mayo Clinic basic science or behavioral cancer research lab for Navajo undergraduate students. Seven Native American undergraduate students (five females, two males) were enrolled during the summers of 2008-2011. Students reported the program influenced their career goals and was valuable to their education and development. These efforts may increase the number of Native American career scientists developing and implementing cancer research, which will ultimately benefit the health of Native American people.

The Middle Jurassic basinal deposits of the Surmeh Formation in the Central Zagros Mountains, southwest Iran: Facies, sequence stratigraphy, and controls

USGS Publications Warehouse

Lasemi, Y.; Jalilian, A.H.

2010-01-01

systems tract of a depositional sequence and grades upward to platform margin and platform interior facies as a result of late highstand basinward progradation. The sedimentary record of the 'lower shaley unit' in the Central Zagros region reveals the existence of a northwest-southeast trending platform margin during the Middle Jurassic that faced a deep basin, the 'Pars intrashelf basin' in the northeast. The thinning of calciturbidite layers towards the northeast and the widespread Middle Jurassic platform carbonates in the southern Persian Gulf states and in the Persian Gulf area support the existence of a southwest platform margin and platform interior source area. The platform margin was formed as a result of tectonic activity along the preexisting Mountain Front fault associated with Cimmerian continental rifting in northeast Gondwana. Flooding of the southwest platform margin during early to middle Bajocian resulted in the reestablishment of the carbonate sediment factory and overproduction of shallow marine carbonates associated with sea-level highstand, which led to vertical and lateral expansion of the platform and gradual infilling of the Pars intrashelf basin by late Bajocian time. ?? 2010 Springer-Verlag.

A late Jurassic pterosaur (Reptilia, Pterodactyloidea) from northwestern Patagonia, Argentina

NASA Astrophysics Data System (ADS)

Codorniú, Laura; Gasparini, Zulma; Paulina-Carabajal, Ariana

2006-03-01

A small to medium-sized pterodactyloid pterosaur (wingspan approximately 1.10 m) from the Upper Jurassic (middle-late Tithonian) marine deposits of the Vaca Muerta Formation of Patagonia (Los Catutos area, central Neuquén Province, Argentina) is reported. The specimen lacks the skull but constitutes a nearly complete postcranial skeleton, which includes cervical and dorsal vertebrae; a few thoracic ribs; both pectoral girdles; the left pelvic girdle; a proximal right wing (humerus, ulna, and radius) and metacarpal IV; a left wing that lacks only wing phalanx four; and both hindlimbs, the right one without the foot. Ontogenetic features suggest that the new fossil corresponds to a relatively mature individual, probably a subadult. Observed characters support its assignment to the Archaeopteroactyloidea, a basal clade within the Pterodactyloidea. This specimen is the second pterosaur from Los Catutos and the most complete Jurassic pterosaur so far known from South America.

Examining the Lives of Navajo Native American Teenage Mothers in Context: A 12- to 15-Year Follow-Up

ERIC Educational Resources Information Center

Dalla, Rochelle L.; Jacobs-Hagen, Susan B.; Jareske, Betsy K.; Sukup, Julie L.

2009-01-01

In 1992 and 1995, data were collected from 29 Navajo, reservation-residing teenage mothers. In 2007, follow-up data from 69% (n = 20) of the original sample were collected. Intensive interviews, grounded in ecological systems theory (U. Bronfenbrenner, 1989), allowed for contextual examination of the women's developmental trajectories. Significant…

A possible terrestrial analogue for haematite concretions on Mars.

PubMed

Chan, Marjorie A; Beitler, Brenda; Parry, W T; Ormö, Jens; Komatsu, Goro

2004-06-17

Recent exploration has revealed extensive geological evidence for a water-rich past in the shallow subsurface of Mars. Images of in situ and loose accumulations of abundant, haematite-rich spherical balls from the Mars Exploration Rover 'Opportunity' landing site at Meridiani Planum bear a striking resemblance to diagenetic (post-depositional), haematite-cemented concretions found in the Jurassic Navajo Sandstone of southern Utah. Here we compare the spherical concretions imaged on Mars to these terrestrial concretions, and investigate the implications for analogous groundwater-related formation mechanisms. The morphology, character and distribution of Navajo haematite concretions allow us to infer host-rock properties and fluid processes necessary for similar features to develop on Mars. We conclude that the formation of such spherical haematite concretions requires the presence of a permeable host rock, groundwater flow and a chemical reaction front.

The Prospects for Navajo Taxation of Non-Indians. Lake Powell Research Project Bulletin Number 19, March 1976.

ERIC Educational Resources Information Center

Goldberg, Carole E.

In the past, courts have described American Indian sovereignty in ways that suggest the existence of power in the Navajo Tribe to tax the activities and property of non-Indians on their reservation. These judicial statements were made, however, at a time when tribal governments were viewed as transitional mechanisms for Indian assimilation, and…

Demographic Change Among the Hopi and Navajo Indians. Lake Powell Research Project Bulletin Number 2, October 1973.

ERIC Educational Resources Information Center

Kunitz, Stephen J.

Concerned with historical patterns and with comparisons from one area to another, this report traced the growth of the Navajo and Hopi populations over the past 100 years (1870-1970). Data on fertility, mortality, and migration were obtained from the: Indian Health Service, Bureau of Indian Affairs, U.S. Public Health Service Office of Vital…

The Upper Jurassic Stanleyville Group of the eastern Congo Basin: An example of perennial lacustrine system

NASA Astrophysics Data System (ADS)

Caillaud, Alexis; Blanpied, Christian; Delvaux, Damien

2017-08-01

The intracratonic Congo Basin, located in the Democratic Republic of Congo (DRC), is the largest sedimentary basin of Africa. The Jurassic strata outcrop along its eastern margin, south of Kisangani (formerly Stanleyville). In the last century, the Upper Jurassic Stanleyville Group was described as a lacustrine series containing a thin basal marine limestone designed as the ;Lime Fine; beds. Since the proposal of this early model, the depositional environment of the Stanleyville Group, and especially the possible marine incursion, has been debated, but without re-examining the existing cores, outcrop samples and historical fossils from the type location near Kisangani that are available at the Royal Museum for Central Africa (MRAC/KMMA, Tervuren, Belgium). In order to refine the former sedimentology, a series of nine exploration cores drilled in the Kisangani sub-basin have been described. This study aims at integrating sedimentary facies in existing sedimentary models and to discuss the hypothesis of the presence of Kimmeridgian marine deposits along the Congo River near Kisangani, a region which lies in the middle of the African continent. Eight facies have been identified, which permit a reinterpretation of the depositional environment and paleogeography of the Stanleyville Group. The base of the Stanleyville Group is interpreted to represent a conglomeratic fluvial succession, which filled an inherited Triassic paleotopography. Above these conglomerates, a transition to a typically lacustrine system is interpreted, which includes: (1) a basal profundal, sublittoral (brown to dark fine-grained siltstones with microbial carbonates, i.e., the ;Lime Fine; beds) and littoral lacustrine series; covered by (2) a sublittoral to profundal interval (brown to dark organic-rich, fine-grained siltstones), which corresponds to the maximum extent of the paleo-lake; and, finally (3) a shallow lacustrine series (greenish calcareous siltstones and sandstones with red siltstones

Ichnological evidence of Megalosaurid Dinosaurs Crossing Middle Jurassic Tidal Flats

NASA Astrophysics Data System (ADS)

Razzolini, Novella L.; Oms, Oriol; Castanera, Diego; Vila, Bernat; Santos, Vanda Faria Dos; Galobart, Àngel

2016-08-01

A new dinosaur tracksite in the Vale de Meios quarry (Serra de Aire Formation, Bathonian, Portugal)preserves more than 700 theropod tracks. They are organized in at least 80 unidirectional trackways arranged in a bimodal orientation pattern (W/NW and E/SE). Quantitative and qualitative comparisons reveal that the large tridactyl, elongated and asymmetric tracks resemble the typical Late Jurassic-Early Cretaceous Megalosauripus ichnogenus in all morphometric parameters. Few of the numerous tracks are preserved as elite tracks while the rest are preserved as different gradients of modified true tracks according to water content, erosive factors, radial fractures and internal overtrack formations. Taphonomical determinations are consistent with paleoenvironmental observations that indicate an inter-tidal flat located at the margin of a coastal barrier. The Megalosauripus tracks represent the oldest occurrence of this ichnotaxon and are attributed to large megalosaurid dinosaurs. Their occurrence in Vale de Meios tidal flat represents the unique paleoethological evidence of megalosaurids moving towards the lagoon, most likley during the low tide periods with feeding purposes.

Ichnological evidence of Megalosaurid Dinosaurs Crossing Middle Jurassic Tidal Flats.

PubMed

Razzolini, Novella L; Oms, Oriol; Castanera, Diego; Vila, Bernat; Santos, Vanda Faria Dos; Galobart, Àngel

2016-08-19

A new dinosaur tracksite in the Vale de Meios quarry (Serra de Aire Formation, Bathonian, Portugal)preserves more than 700 theropod tracks. They are organized in at least 80 unidirectional trackways arranged in a bimodal orientation pattern (W/NW and E/SE). Quantitative and qualitative comparisons reveal that the large tridactyl, elongated and asymmetric tracks resemble the typical Late Jurassic-Early Cretaceous Megalosauripus ichnogenus in all morphometric parameters. Few of the numerous tracks are preserved as elite tracks while the rest are preserved as different gradients of modified true tracks according to water content, erosive factors, radial fractures and internal overtrack formations. Taphonomical determinations are consistent with paleoenvironmental observations that indicate an inter-tidal flat located at the margin of a coastal barrier. The Megalosauripus tracks represent the oldest occurrence of this ichnotaxon and are attributed to large megalosaurid dinosaurs. Their occurrence in Vale de Meios tidal flat represents the unique paleoethological evidence of megalosaurids moving towards the lagoon, most likley during the low tide periods with feeding purposes.

Vegetation of semi-stable rangeland dunes of the Navajo Nation, Southwestern USA

USGS Publications Warehouse

Thomas, Kathryn A.; Redsteer, Margaret H.

2016-01-01

Dune destabilization and increased mobility is a worldwide issue causing ecological, economic, and health problems for the inhabitants of areas with extensive dune fields. Dunes cover nearly a third of the Navajo Nation within the Colorado Plateau of southwestern USA. There, higher temperatures and prolonged drought beginning in 1996 have produced significant increases in dune mobility. Vegetation plays an important role in dune stabilization, but there are few studies of the plants of the aeolian surfaces of this region. We examined plant species and their attributes within a moderately vegetated dune field of the Navajo Nation to understand the types and characteristics of plants that stabilize rangeland dunes. These dunes supported a low cover of mixed grass-scrubland with fifty-two perennial and annual species including extensive occurrence of non-native annual Salsola spp. Perennial grass richness and shrub cover were positively associated with increased soil sand composition. Taprooted shrubs were more common on sandier substrates. Most dominant grasses had C4 photosynthesis, suggestive of higher water-use efficiencies and growth advantage in warm arid environments. Plant cover was commonly below the threshold of dune stabilization. Increasing sand movement with continued aridity will select for plants adapted to burial, deflation, and abrasion. The study indicates plants tolerant of increased sand mobility and burial but more investigation is needed to identify the plants adapted to establish and regenerate under these conditions. In addition, the role of Salsola spp. in promoting decline of perennial grasses and shrubs needs clarification.

Mirolydidae, a new family of Jurassic pamphilioid sawfly (Hymenoptera) highlighting mosaic evolution of lower Hymenoptera.

PubMed

Wang, Mei; Rasnitsyn, Alexandr P; Yang, Zhongqi; Shih, Chungkun; Wang, Hongbin; Ren, Dong

2017-03-07

We describe Pamphilioidea: Mirolydidae Wang, Rasnitsyn et Ren, fam. n., containing Mirolyda hirta Wang, Rasnitsyn et Ren, gen. et sp. n., from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. The new taxon is characterized by unique forewing venation with the presence of forewing SC, 1-RS almost as long as 1-M, M + Cu straight, 2r-rs strongly reclival, and antenna with homonomous flagellum, revealing new and important details in antennal evolutionary transformations. Thus, M. hirta with a combination of primitive and more derived characters highlights its transitional state in the Pamphilioidea and complex mosaic evolution within Pamphilioidea in the late Middle Jurassic. The body of this species is densely covered with thin and long setae, suggesting its possible habit of visiting gymnosperm reproductive organs for pollen feeding and/or pollination during the late Middle Jurassic, much earlier than the appearance of angiosperm flowers.

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.

Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)

NASA Astrophysics Data System (ADS)

Kosakowski, Paweł; Wróbel, Magdalena

2012-08-01

Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.

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

A unique fossil record from neptunian sills: the world's most extreme example of stratigraphic condensation (Jurassic, western Sicily)

NASA Astrophysics Data System (ADS)

Wendt, Jobst

2017-06-01

Neptunian sills at Rocca Busambra, a fragment of the Trapanese/Saccense Domain in western Sicily, host the most abundant ammonite and gastropod fauna which has ever been recorded from the Jurassic of the western Tethys. The fauna is dominated by parautochthonous organisms which were swept into the sills by gentle transport. Ammonites are characterized by perfect preservation and small size, a feature which is due to the predominance of microconchs but also of stunting. The most complete sill is 0.7 m thick and could be separated into 17 levels which range in age from the early Toarcian into the late Kimmeridgian, thus representing the most extreme case of palaeontologically and depositionally documented stratigraphic condensation in Earth history. The unique feature of the Rocca Busambra sills is due to the interaction of three processes: extreme stratigraphic condensation on the sea floor, weak tectonic fracturing of the host rock and repeated reopening on top of already existing sills. Contrasting percentages of gastropods in individual levels reflect sea-level oscillations which correspond to long known low- and highstands during the Jurassic of the western Tethys. Comparisons with other ammonite-bearing sill faunas reveal several similarities, but represent only short-timed phases of tectonic pulses and deposition.

The role of deep Earth dynamics in driving the flooding and emergence of New Guinea since the Jurassic

NASA Astrophysics Data System (ADS)

Harrington, Lauren; Zahirovic, Sabin; Flament, Nicolas; Müller, R. Dietmar

2017-12-01

The paleogeography of New Guinea indicates fluctuating periods of flooding and emergence since the Jurassic, which are inconsistent with estimates of global sea level change since the Eocene. The role of deep Earth dynamics in explaining these discrepancies has not been explored, despite the strongly time-dependent geodynamic setting within which New Guinea has evolved. We aim to investigate the role of subduction-driven mantle flow in controlling long-wavelength dynamic topography and its manifestation in the regional sedimentary record, within a tectonically complex region leading to orogeny. We couple regionally refined global plate reconstructions with forward geodynamic models to compare trends of dynamic topography with estimates of eustasy and regional paleogeography. Qualitative corroboration of modelled mantle structure with equivalent tomographic profiles allows us to ground-truth the models. We show that predicted dynamic topography correlates with the paleogeographic record of New Guinea from the Jurassic to the present. We find that subduction at the East Gondwana margin locally enhanced the high eustatic sea levels from the Early Cretaceous (∼145 Ma) to generate long-term regional flooding. During the Miocene, however, dynamic subsidence associated with subduction of the Maramuni Arc played a fundamental role in causing long-term inundation of New Guinea during a period of global sea level fall.

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

Mesozoic units in SE Rhodope (Bulgaria): new structural and petrologic data and geodynamic implications for the Early Jurassic to Mid-Cretaceous evolution of the Vardar ocean basin

NASA Astrophysics Data System (ADS)

Bonev, N.; Stampfli, G.

2003-04-01

. Immobile trace element discrimination of both rock types constrains the volcanic (oceanic)-arc origin. They generally show low total REE concentrations (LREE>HREE) with enrichment of LIL elements relative to the HFS elements, and also very low Nb and relatively high Ce content consistent with an island-arc tectonic setting. We consider that the Meliata-Maliac ocean northern passive margin could be the source provenance for the Upper Permian clastics and Middle-Upper Triassic limestone blocks within the olistostromic melange-like unit, whereas turbidites and magmatic blocks may originate in an island arc-accretionary complex that relates to the southward subduction of the Maliac ocean under the supra-subduction back-arc Vardar ocean/island arc system. These new structural and petrologic data allow to precise the tectonic setting of the Mesozoic units and their geodynamic context in the frame of the Early Jurassic to Late Cretaceous evolution of the Vardar ocean.

New model for Jurassic microcontinent movement and Gondwana breakup in the Weddell Sea region

NASA Astrophysics Data System (ADS)

Jordan, Tom; Ferraccioli, Fausto; Leat, Philip

2017-04-01

The breakup of the Gondwana supercontinent changed the face of our planet. Precursors of supercontinental breakup are widely recognised in the Weddell Sea region in the Jurassic. These include the Karoo/Ferrar Large Igneous Province that extends from South Africa to East Antarctica and significant continental rifting and associated translation of microcontinental blocks in the Weddell Sea Embayment region. However, significant controversy surrounds the pre-breakup position, extent, timing and driving mechanism of inferred microcontinental movement. In particular geological and paleomagnetic data suggest >1000 km of translation and 90 degree rotation of the Haag-Ellsworth Whitmore block (HEW) away from East Antarctica. In contrast, some geophysical interpretations suggest little or no Jurassic or subsequent HEW block movement. Here we present a simpler tectonic model for the Weddell Sea Rift System and HEW movement, derived from our new compilation of airborne geophysical data, satellite magnetic data and potential field modelling (Jordan et al., 2016- Gondwana Res.). Based on the amount of inferred Jurassic crustal extension and pattern of magnetic anomalies we propose that the HEW was translated 500 km towards the Paleo-Pacific margin of Gondwana, possibly in response to a process of slab roll-back that led to distributed back-arc extension in the Weddell Sea Rift System. Widespread magmatism in the region was likely influenced by the presence of one or more mantle plumes impinging beneath the stretching lithosphere. A second phase of continental extension is inferred to have occurred between 180 and 165 Ma (prior to seafloor spreading) and is more closely associated with Gondwana breakup. This second phase over-printed the northern part of the older back arc system. We find no geophysical evidence indicating more than 30 degrees of syn-extensional HEW rotation during Jurassic rifting in the southern Weddell Sea Rift System. Instead, we propose the majority ( 60

Mid-Mesozoic (Mid-Jurassic to Early Cretaceous) evolution of the Georges Bank Basin, U.S. North Atlantic outer continental shelf: Sedimentology of the Conoco 145-1 well

USGS Publications Warehouse

Poppe, L.J.; Poag, C.W.; Stanton, R.W.

1992-01-01

The Conoco 145-1 exploratory well, located in the southeastern portion of the Georges Bank Basin, was drilled to a total depth of 4303 m below the sea floor. The oldest sedimentary rocks sampled are of Middle Jurassic age (Late Bathonian-Callovian). A dolomite-limestone-evaporite sequence dominates the section below 3917 m; limestone is the predominant lithology in the intervals of 3271-3774 m, 2274-3158 m, and 1548-1981 m. Siliciclastics dominate the remainder of the drilled section. Calcite tightly cements most of the rocks below 1548 m; dolomite, silica, siderite, and diagenetic clay cements are locally important. Restricted inner marine environments, representing lagoonal and tidal flat conditions, prevailed at the wellsite during much of the deposition recorded by the Callovian-Bathonian age Iroquois Formation. These environments gave way to a carbonate platform, which formed part of the > 5,000 km long Bahama-Grand Banks gigaplatform that lasted through the end of the Late Jurassic (encompassing the uppermost portion of the Iroquois Formation and the Scatarie Limestone and Bacarro Limestone Members of the Abenaki Formation). The absence of a skeletal-reef association and the dominance of muddy limestone fabrics are evidence that the 145-1 wellsite was located on the platform interior. Major periods of siticiclastic deposition interrupted carbonate deposition, and they are recorded by stratigraphic equivalents of the Mohican Formation, Misaine Shale Member of the Abenaki Formation, and the Mohawk and Mic Mac Formations. A series of sustained prograding delta systems, the earliest of which is preserved as the Missisauga Formation, buried the carbonate platform following its drowning in the Early Cretaceous (Berriasian-Valanginian). The sparser, primarily allochthonous lignite content and better-sorted, glauconite-bearing sands of the Missisauga strata at the 145-1 wellsite suggest that shallow marine or barrier-bar environments were more prevalent than the low

The Navajo country: A geographic and hydrographic reconnaissance of parts of Arizona, New Mexico and Utah

USGS Publications Warehouse

Gregory, Herbert E.

1916-01-01

To my mind the period of direct contact with nature is the true "heroic age" of human history, an age in which heroic accomplishment and heroic endurance are parts of the daily routine. The activities of people on this stage of progress deserve a place among the cherished traditions of the human race. I believe also that the sanest missionary effort includes an endeavor to assist the uncivilized man in his adjustment to natural laws. With these ideas in mind the opportunity to conduct exploratory work in the Navajo country appealed to me with peculiar force. Within this little-known region are the remnants of an almost extinct race whose long occupation of the country is recorded in ruined dwellings and abandoned fields. This country is also the home of the vigorous and promising Navajos - a tribe in remarkably close adjustment to their physical surroundings. To improve the condition of this long-neglected but capable race, to render their life more intelligently wholesome by applying scientific knowledge, gives pleasure in no degree less than that obtained by the study of the interesting geologic problems which this country affords.

Final results on the Jurassic-Cretaceous boundary in the Gresten Klippenbelt (Austria): Macro-, micro-, nannofossils, isotopes, geochemistry, susceptibility, gamma-log and palaeomagnetic data as environmental proxies of the early Penninic Ocean history

NASA Astrophysics Data System (ADS)

Lukeneder, A.; Halásová, E.; Kroh, A.; Mayrhofer, S.; Pruner, P.; Reháková, D.; Schnabl, P.; Sprovieri, M.

2009-04-01

Jurassic to Lower Cretaceous pelagic sediments are well known to form a major element of the northernmost tectonic units of the Gresten Klippenbelt (Lower Austria). The Penninic Ocean was a side tract of the Central Atlantic Oceanic System intercalated between the European and the Austroalpine plates. Its opening started during the Mid Jurrasic, as rifting of the of the oceanic crust between the European and the Austroalpine plates. The turnover of the deposition on the European shelf (Helvetic Zone) from deep-water siliciclastics into pelagic carbonates is correlated with the deepening of this newly arising ocean. Within the Gresten Klippenbelt Unit, this transition is reflected by the lithostratigraphic boundary between the Tithonian marl-limestone succession and the Berriasian limestones of the Blassenstein Formation. This boundary is well exposed in a newly discovered site at Nutzhof, in the heart of Lower Austria (Kroh and Lukeneder 2009, Lukeneder 2009, Pruner, Schnabl, and Lukeneder 2009, Reháková, Halásová and Lukeneder 2009). Biostratigraphy. According to microfossil (calcareous dinoflagellates, calpionellids) and palaeomagnetic data, the association indicates that the cephalopod-bearing beds of the Nutzhof section belong to the Carpistomiosphaera tithonica-Zone of the Early Tithonian up to the Calpionella Zone of the Middle Berriasian. This interval corresponds to the ammonoid zones from the Early Tithonian Hybonoticeras hybonotum-Zone up to the Middle Berriasian Subthurmannia occitanica-Zone. Ammonoids. Late Jurassic to Early Cretaceous ammonoids were collected at the Nutzhof locality in the eastern part of the Gresten Klippenbelt in Lower Austria. The cephalopod fauna from the Blassenstein Formation, correlated with micro- and nannofossil data from the marly unit and the limestone unit, indicates Early Tithonian to Middle Berriasian age (Hybonoticeras hybonotum Zone up to the Subthurmannia occitanica Zone). According to the correlation of the fossil

Discovery of silicified lacustrine micro-fossils and stromatolites: Triassic-Jurassic Fundy Group, Nova Scotia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cameron, B.

A unique assemblage of silicified invertebrate and algal fresh-water lake fossils has been discovered in the Scots Bay Formation at the top of the Triassic-Jurassic Fundy Group of the Fundy Basin in Nova Scotia. This is important because the basins of the eastern North American Triassic-Jurassic rift system have not yielded many invertebrate and algal fossils. These new finds will contribute significantly to evolutionary, paleoecological and biostratigraphic studies of fresh-water Mesozoic deposits. Silicified fossils have been extracted from chert-bearing, mixed carbonate and siliciclastic lithologies. They include ostracodes, gastropods, rare bivalves, charaphytes (algae), stromatolites, and chert nodules cored with well-preserved woodymore » tissues of tree trunks. Possible algal filaments occur in the silicified stromatolites. This association of charaphytes, ostracodes, microscopic gastropods and stromatolites is found in carbonate lakes today. The Scots Bay Formation is probably a near-shore carbonate facies of the more widespread silicilastic lacustrine McCoy Brook Formation. The gastropods and ostracodes, studied by SEM, indicate a Jurassic age for the Scots bay Formation, confirming speculations based on other data.« less

New Insights into the Provenance of the Southern Junggar Basin in the Jurassic from Heavy Mineral Analysis and Sedimentary Characteristics

NASA Astrophysics Data System (ADS)

Zhou, T. Q.; Wu, C.; Zhu, W.

2017-12-01

Being a vital component of foreland basin of Central-western China, Southern Junggar Basin has observed solid evidences of oil and gas in recent years without a considerable advancement. The key reason behind this is the lack of systematic study on sedimentary provenance analysis of the Southern Junggar basin. Three parts of the Southern Junggar basin, including the western segment (Sikeshu Sag), the central segment (Qigu Fault-Fold Belt) and the eastern segment (Fukang Fault Zone), possess varied provenance systems, giving rise to difficulties for oil-gas exploration. In this study, 3468 heavy minerals data as well as the sedimentary environment analysis of 10 profiles and 7 boreholes were used to investigate the provenances of the deposits in the southern Junggar basin . Based on this research, it reveals that: Sikeshu sag initially shaped the foreland basin prototype in the Triassic and its provenance area of the sediments from the Sikeshu sag has primarily been situated in zhongguai uplift-chepaizi uplift depositional systems located in the northwestern margin of the Junggar Basin. From the early Jurassic, the key sources were likely to be late Carboniferous to early Permain post-collisional volcanic rocks from the North Tian Shan block to Centrao Tian Shan. In the Xishanyao formation, Abundant lithic metamorphic, epidote and garnet that suggests the source rocks were possibly late Carboniferous subduction-related arc volcanic rocks of the Central Tian Shan. In the Toutunhe formation, Bogda Mountains began uplifting and gradually becoming the major provenance. Moreover, the sedimentary boundaries of Junggar basin have also shifted towards the North Tian Shan again. In the late Jurassic, the conglomerates of the Kalazha formation directly overlie the fine-grained red beds of Qigu formation, which throw light on the rapid tectonic uplift of the North Tian Shan. In the eastern segment, meandering river delta and shore-lacustrine environments were fully developed

Thermochronological Record of a Jurassic Heating-Cooling Cycle Within a Distal Rifted Margin (Calizzano Massif, Ligurian Alps)

NASA Astrophysics Data System (ADS)

Seno, S.; Decarlis, A.; Fellin, M. G.; Maino, M.; Beltrando, M.; Ferrando, S.; Manatschal, G.; Gaggero, L.; Stuart, F. M.

2017-12-01

The aim of the present study is to analyse, through thermochronological investigations, the thermal evolution of a fossil distal margin owing to the Alpine Tethys rifting system. The studied distal margin section consists of a polymetamorphic basement (Calizzano basement) and of a well-developed Mesozoic sedimentary cover (Case Tuberto unit) of the Ligurian Alps (NW Italy). The incomplete reset of zircon (U-Th)/He ages and the non-reset of the zircon fission track ages during the Alpine metamorphism indicate that during the subduction and the orogenic stages these rocks were subjected to temperatures lower than 200 ºC. Thus, the Alpine metamorphic overprint occurred during a short-lived, low temperature pulse. The lack of a pervasive orogenic reset, allowed the preservation of an older heating-cooling event that occurred during Alpine Tethys rifting. Zircon fission-track data indicate, in fact, that the Calizzano basement records a cooling under 240 °C, at 156 Ma (early Upper Jurassic). This cooling followed a Middle Jurassic syn-rift heating at temperatures of about 300-350°C, typical of greenschist facies conditions occurred at few kilometres depth, as indicated by stratigraphic and petrologic constraints. Thus, in our interpretation, major crustal thinning likely promoted high geothermal gradients ( 60-90°C/km) triggering the circulation of hot, deep-seated fluids along brittle faults, causing the observed thermal anomaly at shallow crustal level.

Map of Water Infrastructure and Homes Without Access to Safe Drinking Water and Basic Sanitation on the Navajo Nation - October 2010

EPA Pesticide Factsheets

This document presents the results of completed work using existing geographic information system (GIS) data to map existing water and sewer infrastructure and homes without access to safe drinking water and basic sanitation on the Navajo Nation.

Bokan Mountain peralkaline granitic complex, Alexander terrane (southeastern Alaska): evidence for Early Jurassic rifting prior to accretion with North America

USGS Publications Warehouse

Dostal, Jaroslav; Karl, Susan M.; Keppie, J. Duncan; Kontak, Daniel J.; Shellnutt, J. Gregory

2013-01-01

The circular Bokan Mountain complex (BMC) on southern Prince of Wales Island, southernmost Alaska, is a Jurassic peralkaline granitic intrusion about 3 km in diameter that crosscuts igneous and metasedimentary rocks of the Alexander terrane. The BMC hosts significant rare metal (rare earth elements, Y, U, Th, Zr, and Nb) mineralization related to the last stage of BMC emplacement. U–Pb (zircon) and 40Ar/39Ar (amphibole and whole-rock) geochronology indicates the following sequence of intrusive activity: (i) a Paleozoic basement composed mainly of 469 ± 4 Ma granitic rocks; (ii) intrusion of the BMC at 177 ± 1 Ma followed by rapid cooling through ca. 550 °C at 176 ± 1 Ma that was synchronous with mineralization associated with vertical, WNW-trending pegmatites, felsic dikes, and aegirine–fluorite veins and late-stage, sinistral shear deformation; and (iii) intrusion of crosscutting lamprophyre dikes at >150 Ma and again at ca. 105 Ma. The peralkaline nature of the BMC and the WNW trend of associated dikes suggest intrusion during NE–SW rifting that was followed by NE–SW shortening during the waning stages of BMC emplacement. The 177 Ma BMC was synchronous with other magmatic centres in the Alexander terrane, such as (1) the Dora Bay peralkaline stock and (2) the bimodal Moffatt volcanic suite located ∼30 km north and ∼100 km SE of the BMC, respectively. This regional magmatism is interpreted to represent a regional extensional event that precedes deposition of the Late Jurassic – Cretaceous Gravina sequence that oversteps the Wrangellia and Alexander exotic accreted terranes and the Taku and Yukon–Tanana pericratonic terranes of the Canadian–Alaskan Cordillera.