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Sample records for dyke karen woodfork

  1. Karen Avetovich

    NASA Astrophysics Data System (ADS)

    Shifman, M.

    2013-06-01

    I was never a student of Karen Avetovich (Karen, as everyone called him behind his back) and never collaborated with him. I've never worked on Reggeistics - the area of high-energy physics that was close to his heart. For an understandable reason - a thirty-year age difference - I couldn't be his close friend. And yet I decided to write a few kind words about Ter-Martirosyan for a reason which will soon become clear...

  2. Health Information in Karen (Sgaw Karen): MedlinePlus

    MedlinePlus

    ... Sgaw Karen (Karen) Multimedia Healthy Roads Media How you get HIV/AIDS - English Sgaw Karen (Karen) PDF Healthy Roads Media How you get HIV/AIDS - English Sgaw Karen (Karen) Multimedia Healthy Roads Media ...

  3. Memories of Karen Avetovich

    NASA Astrophysics Data System (ADS)

    Nevzorov, Roman

    2013-06-01

    Karen Avetovich Ter-Martirosyan (K.A.) was at once my teacher, scientific adviser, and collaborator. My communication with K.A. enormously influenced my life and career; he helped me to establish the basic values and principles that I try to follow in my everyday life and research activities...

  4. a Few Lines about Karen

    NASA Astrophysics Data System (ADS)

    Smorodinskaya, Noemi

    2013-06-01

    Karen had tons of amazing students, and it's unfortunate that they could not contribute to this collection. They would have a lot of marvelous stories to tell, since they spent so many days and nights at Karen's house, enjoying Bella Artemievna's hospitality and kindness. Karen was a difficult person, with many eccentricities, but at the same time he was very kind and forgiving. When people he knew had troubles, he always did whatever he could to help them. I should add, however, that due to the many tragedies he had experienced in his family life, Karen's threshold for what counted as troubles was unusually high, and what others perceived as major problems struck him as the minor complications of everyday life...

  5. Talking about Books: Karen Hesse.

    ERIC Educational Resources Information Center

    Beck, Cathy; Gwyn, Linda; Koblitz, Dick; O'Connor, Anne; Pierce, Kathryn Mitchell; Wolf, Susan

    1999-01-01

    Presents an interview with Karen Hesse, author of 12 books of fiction for young, middle, and older readers, and winner of the 1998 Newbery Award. Offers an overview of Hesse's books, organized into picture books, transition chapter books, and novels. Presents a discussion of the themes found in her books, highlighting children's discussion…

  6. Karen Avetovich Ter-Martirosyan

    NASA Astrophysics Data System (ADS)

    Shifman, M.

    2013-06-01

    One can say that Karen Avetovich Ter-Martirosyan was one of the stars in the brilliant constellation of theoretical physicists dating back to the golden era of Soviet physics: a disciple of Yakov Frenkel and Lev Landau, he was one of the creators of the theory of (soft) strong interactions at high energies...

  7. An Interview with Karen Glover

    ERIC Educational Resources Information Center

    Power, June

    2011-01-01

    This article presents an interview with Karen Glover of Georgia Tech, a key person behind the planning of the Access Services Conference held last fall, and now going into its second year. Glover started working in libraries as a part-time library assistant at her local public library during her high school years. She later became a Circulation…

  8. Finding General Dyke.

    PubMed

    Dyke, Charles William; Dyke, Ann Bisconti

    2011-01-01

    A hemorrhagic stroke and aphasia suddenly changed the life of Charles William (Bill) Dyke, Army Lt. General (Retired), Ranger strong with 2 silver stars and 3 bronze stars among his many decorations and founder and CEO of a Washington, DC, consulting firm. Gen. Dyke and his wife Ann provide their personal perspectives on the path to his remarkable recovery and return to full-time work. They found that the most effective therapy linked to who he was and is. Standard therapy tools and impersonal approaches frequently created barriers. Instead, when health professionals related the therapy objectives to his interests and involved him in the process of setting objectives to meet the challenges, they gained his trust, cooperation, participation, and focus on learning. PMID:21447463

  9. Speaking Personally--With Karen Cator

    ERIC Educational Resources Information Center

    American Journal of Distance Education, 2010

    2010-01-01

    This article presents an interview by Gary E. Miller, executive director emeritus of Penn State World Campus, the online distance education campus of The Pennsylvania State University, with Karen Cator, director of the Office of Educational Technology in the United States Department of Education. She brings to the position a mix of corporate and…

  10. A Q & A with Karen Hughes

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2007

    2007-01-01

    This article presents an excerpt from the interview of Karen Hughes, under secretary of state for public diplomacy and public affairs. Hughes discusses the Bush administration's effort to attract foreign students to the United States and to send American students overseas. She also talks about what American colleges and universities can do to help.

  11. The Errors of Karen Franklin's Pretextuality

    PubMed Central

    Cantor, James M.

    2012-01-01

    In her recent article, Hebephilia: Quintessence of Diagnostic Pretextuality (published in Behavioral Sciences and the Law, 2010), Karen Franklin expands on her previous argument that psychologists and psychiatrists should not diagnose as abnormal hebephilia, the sexual preference for early pubescent children. She supports her argument with a series of claims about the contents of the empirical literature and the scientists who produced it. The present document provides fact-checking of those claims, revealing that Franklin's conclusions are based largely on demonstrable falsehoods. PMID:22745581

  12. 77 FR 26766 - Karen L. Blyth: Debarment Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-07

    ... HUMAN SERVICES Food and Drug Administration Karen L. Blyth: Debarment Order AGENCY: Food and Drug... under the Federal Food, Drug, and Cosmetic Act (FD&C Act) debarring Karen L. Blyth for a period of 20.... FDA bases this order on a finding that Ms. Blyth was convicted, as defined in section 306(l)(1)(B)...

  13. Magma deformation and emplacement in rhyolitic dykes

    NASA Astrophysics Data System (ADS)

    McGowan, Ellen; Tuffen, Hugh; James, Mike; Wynn, Peter

    2016-04-01

    Silicic eruption mechanisms are determined by the rheological and degassing behaviour of highly-viscous magma ascending within shallow dykes and conduits. However, we have little knowledge of how magmatic behaviour shifts during eruptions as dykes and conduits evolve. To address this we have analysed the micro- to macro-scale textures in shallow, dissected rhyolitic dykes at the Tertiary Húsafell central volcano in west Iceland. Dyke intrusion at ~3 Ma was associated with the emplacement of subaerial rhyolitic pyroclastic deposits following caldera formation[1]. The dykes are dissected to ~500 m depth, 2-3 m wide, and crop out in two stream valleys with 5-30 m-long exposures. Dykes intrude diverse country rock types, including a welded ignimbrite, basaltic lavas, and glacial conglomerate. Each of the six studied dykes is broadly similar, exhibiting obsidian margins and microcrystalline cores. Dykes within pre-fractured lava are surrounded by external tuffisite vein networks, which are absent from dykes within conglomerate, whereas dykes failed to penetrate the ignimbrite. Obsidian at dyke margins comprises layers of discrete colour. These display dramatic thickness variations and collapsed bubble structures, and are locally separated by zones of welded, brecciated and flow-banded obsidian. We use textural associations to present a detailed model of dyke emplacement and evolution. Dykes initially propagated with the passage of fragmented, gas-charged magma and generation of external tuffisite veins, whose distribution was strongly influenced by pre-existing fractures in the country rock. External tuffisites retained permeability throughout dyke emplacement due to their high lithic content. The geochemically homogenous dykes then evolved via incremental magma emplacement, with shear deformation localised along emplacement boundary layers. Shear zones migrated between different boundary layers, and bubble deformation promoted magma mobility. Brittle

  14. Keystone characteristics that support cultural resilience in Karen refugee parents

    NASA Astrophysics Data System (ADS)

    Harper, Susan G.

    2015-08-01

    This participatory action research study used the conceptual framework of social-ecological resilience to explore how Karen (pronounced Ka·rén) refugee parents re-construct cultural resilience in resettlement. The funds of knowledge approach helped to define essential knowledge used by Karen parents within their own community. Framing this study around the concept of resilience situated it within an emancipatory paradigm: refugee parents were actors choosing their own cultural identity and making decisions about what cultural knowledge was important for the science education of their children. Sustainability science with its capacity to absorb indigenous knowledge as legitimate scientific knowledge offered a critical platform for reconciling Karen knowledge with scientific knowledge for science education. Photovoice, participant observation, and semi-structured interviews were used to create visual and written narrative portraits of Karen parents. Narrative analysis revealed that Karen parents had constructed a counter-narrative in Burma and Thailand that enabled them to resist assimilation into the dominant ethnic culture; by contrast, their narrative of life in resettlement in the U.S. focused on the potential for self-determination. Keystone characteristics that contributed to cultural resilience were identified to be the community garden and education as a gateway to a transformed future. Anchored in a cultural tradition of farming, these Karen parents gained perspective and comfort in continuity and the potential of self-determination rooted in the land. Therefore, a cross-cultural learning community for Karen elementary school students that incorporates the Karen language and Karen self-sustaining knowledge of horticulture would be an appropriate venue for building a climate of reciprocity for science learning.

  15. Caring for the Karen. A newly arrived refugee group.

    PubMed

    Power, David V; Moody, Emily; Trussell, Kristi; O'Fallon, Ann; Chute, Sara; Kyaw, Merdin; Letts, James; Mamo, Blain

    2010-04-01

    Since 2004, Minnesota has seen an influx of refugees from Burma. Many of these newcomers came from the Karen state and spent time in refugee camps in Thailand before resettling in the United States. To better understand the health needs of this population, the authors of this article conducted chart reviews at a St. Paul family medicine clinic that serves a number of Karen refugees and reviewed formal data from the Minnesota Department of Health's Refugee Health Program. Here, they briefly describe this community, the cultural issues that could affect health care providers' ability to care for Karen patients, and the health concerns of these refugees. PMID:20481169

  16. Dyke-Davidoff-Masson syndrome

    PubMed Central

    Kumar, N Vinay; Gugapriya, TS; Guru, Arun T; Kumari, SD Nalina

    2016-01-01

    Dyke-Davidoff-Masson syndrome (DDMS) refers to atrophy or hypoplasia of one cerebral hemisphere, due to an insult to the developing brain in fetal or early childhood period. Age of presentation depends on the time of neurologic insult, and characteristic changes may be seen only in adolescence. Male gender and left hemisphere are more frequently involved. A 17-year-old female adolescent with a history of recurrent refractory seizures, hemiplegia and mental retardation reported to Department of Radiology for computed tomography (CT) assessment of brain. On examination, she had facial asymmetry, delayed milestones, and spastic hemiplegia. The CT brain showed right cortical atrophy with ventricular dilatation, prominent sulci, and shifting of falx to the right side. Bone window image showed asymmetry in skull vault thickness, the width of diploic space, the size of paranasal air sinuses and inclination of the petrous ridge between the affected and normal sides. As the above case deviates from the usual presentation of male left sided DDMS, hence the report. PMID:26958525

  17. Dyke-Davidoff-Masson syndrome.

    PubMed

    Kumar, N Vinay; Gugapriya, T S; Guru, Arun T; Kumari, Sd Nalina

    2016-01-01

    Dyke-Davidoff-Masson syndrome (DDMS) refers to atrophy or hypoplasia of one cerebral hemisphere, due to an insult to the developing brain in fetal or early childhood period. Age of presentation depends on the time of neurologic insult, and characteristic changes may be seen only in adolescence. Male gender and left hemisphere are more frequently involved. A 17-year-old female adolescent with a history of recurrent refractory seizures, hemiplegia and mental retardation reported to Department of Radiology for computed tomography (CT) assessment of brain. On examination, she had facial asymmetry, delayed milestones, and spastic hemiplegia. The CT brain showed right cortical atrophy with ventricular dilatation, prominent sulci, and shifting of falx to the right side. Bone window image showed asymmetry in skull vault thickness, the width of diploic space, the size of paranasal air sinuses and inclination of the petrous ridge between the affected and normal sides. As the above case deviates from the usual presentation of male left sided DDMS, hence the report. PMID:26958525

  18. Determining dyke-propagation paths at Santorini volcano, Greece

    NASA Astrophysics Data System (ADS)

    Drymoni, Kyriaki; Browning, John; Lecoeur, Nora; Gudmundsson, Agust

    2016-04-01

    The volcanic Island of Santorini constitutes a complex of collapse calderas which has experienced a range of explosive and effusive volcanic eruptions and is still active. Numerous stratigraphic horizons which constitute the upper part of the volcano have widely different mechanical properties, resulting in local stresses that may act as dyke-traps, preventing the dykes from reaching the surface to erupt. Several caldera collapses (<3.6 ka) have exposed part of the stratigraphy and a dyke swarm (composed of at least 63 dykes, many arrested and some feeders) within a section of the northern caldera wall, allowing detailed examination. This ongoing study will (1) document the petrological and structural characteristics of feeder and non-feeder (arrested) dykes and estimate their frequency; (2) determine the physiochemical and mechanical conditions that control dyke arrest/dyke penetration at contacts between layers; (3) explore the fluid and mechanical conditions of the associated magma chamber(s) that must be satisfied for chamber rupture and dyke injection to occur; (4) make numerical and probabilistic models as to the likely dyke paths in heterogeneous and anisotropic crustal segments/volcanoes (such as Santorini), including the likelihood of injected dykes reaching the surface during an unrest period in a volcano of a given type; (5) compare the data collected from Santorini with existing data on dykes worldwide, particularly those on dykes in Tenerife and Iceland. The principal aim of the study is to provide models that, during an unrest period in Santorini and other similar volcanoes, allow us to forecast (a) the condition for magma-chamber rupture and dyke injection, and (b) the likely path of the resulting dyke. The latter includes assessment of the likelihood as to dyke arrest versus dyke propagation to the surface, the latter resulting in an eruption. For dyke-fed eruptions, the study will also provide methods for forecasting the likely volumetric flow

  19. Dyke belt in North Western margin of Siberian platform

    NASA Astrophysics Data System (ADS)

    Ryabov, Victor

    2015-04-01

    The Early Triassic dyke swarm belt is strengthening at about 500 km (50-60 km width) along the northern margin of Siberian platform. Its locations is limited from the north by rift structure of the Yenisei-Khatanga trough, and from the south by Kystyktah-Ayan-Ambardah uprise. From west to east dyke belt is crossing Norilsk, Kamensky and Maimecha-Kotuiskaya province. In this direction the composition of dykes changing from basic rthrough alkali-basic to alkali-ultramafic varieties. The sickness of dykes varies from 0,5-10m up to 90 m and length - from 5-15 m to 140 km. The orientation of the bulk of dykes coincides with the direction of the major structural and tectonic lineaments of the region. Dykes are often refer to the fault planes. The composition of dykes may vary along the stretches. The density of hundreds of basaltic dykes and small intrusions in the dyke swarms is not permanent and sometimes essentially uneven. They form a compact dyke swarms of dykes, stocks and sub layering bodies veins. In dyke package on Huor-Uyallah river here are 20 subparallel dykes of different chemical composition at a distance of 2 km Lack of the evidence of the dykes crossing allows to assume their formation during the same magmatic cycle. Dykes cross cut through the entire incision of basaltic plateau. They did not created the flow effusions and refer to the final stage trap magmatism. Ar/Ar age of the youngest dykes in the province Kamenska 238-247 Ma. the age of lamproite dyke in Norilsk province is 235 Ma. Dykes are represented by dolerites trachydolerites, syenites, minettes, lamprophyres (camptonite, spessartite, vosgesite), avgitites, melanephelinite, alnoites, limburgites alkaline picrites, meimechites. Their content vary widely: SiO2 - 35,7-62,6; TiO2- 0,4-7,5; Al2O3- 4,4-17,5; Fe2O3- 4,6-20,6; MnO- 0,08-0,44; MgO- 0,8-31,5; CaO- 0,7-15,4; Na2O- 0,01-6,5; K2O 0,8-5,3 wt.%; P2O5 0,1-1,2 wt.%. The h Bolsheavamskaya volcanic basin in Kamensky province is most abundant in

  20. Predictions for a natural spacing within dyke swarms

    NASA Astrophysics Data System (ADS)

    Menand, T.; Bunger, A. P.; Cruden, A. R.

    2012-12-01

    Dykes often grow next to each other, evidenced by the widespread occurrence of dyke swarms that are comprised of hundreds to thousands of closely-spaced dykes. In giant dyke swarms, that grow to be many times greater in length than the thickness of the crust, dykes are observed to maintain a finite spacing from their neighbors that is tens to hundreds of times smaller than their length. To date, mechanical models have not been able to clarify whether there exists an optimum spacing that would arise naturally between dykes of the same swarm. And yet, the existence of a natural spacing is at the heart of why dykes may grow in swarms in the first place. Here we present and examine a mechanical model for the horizontal propagation of multiple, closely-spaced, blade-like dykes in order to find energetically optimal dyke spacings associated with both constant pressure and constant influx magma sources. We show that the constant pressure source leads to an optimal spacing that is equal to the height of the blade-like dykes. We also show that the constant influx source leads to two candidates for an optimal spacing, one which is expected to be around 0.3 times the dyke height and the other which is expected to be around 2.5 times the dyke height. We conclude that dyke swarms are indeed expected to have a natural spacing that scales with, and is on the order of, the height of the blade-like dykes that comprise the swarm.

  1. Author! Author! Noted Writer of Historical Fiction: Karen Cushman

    ERIC Educational Resources Information Center

    Brodie, Carolyn S.

    2004-01-01

    This article gives a brief biography of author Karen Cushman, best known for the attention to detail and thorough research that goes into her historical novels. Her first two novels, "Catherine, Called Birdy" and "The Midwife's Apprentice" were both Newbery Medal winners. A selected bibliography, as well as a list of related resources, is also…

  2. Writing from the Inside Out: A "Chat" with Karen Cushman.

    ERIC Educational Resources Information Center

    McKindley, Elizabeth Madrid

    1998-01-01

    Interviews Newbery Medal winning author of children's books Karen Cushman about her personal writing process and history. Discusses her early writing experiences, changes at age 50 through which she became an author of children's books, her inner journey as she brings a story to life, and her special writing place and time to muse and do careful…

  3. Centrifuge Tests of Dyke Collapses on Soft Subsoil

    NASA Astrophysics Data System (ADS)

    Fern, J.; de Lange, D.; Zwanenburg, C.; Teunissen, J. A. M.

    2015-09-01

    This paper presents the results of an experimental investigation on the failure or collapse of dykes with a strong contrast of stiffness between the dyke itself and its foundation layers. In deltaic regions, dykes are commonly built out of stiff sandy or clayey materials and rest on soft foundations layers (e.g. soft clay or peat). Their interaction is largely unexplored and the failure mechanism unknown. The tests presented in this paper aim to highlight the difference in failure mechanisms. The tests consisted mainly of stiff dykes on soft subsoils but a few soft dykes on stiff subsoil were also investigated. The dykes were made out of Speswhite clay or Baskarp sand whereas the subsoil was made out of silicon or clay. The silicon was used to replicate a soft elastic subsoil for which it was possible to control the stiffness. The model was then subjected to increasing gravity up to 100 G-level. The results show that slope failures take place in the dyke when the foundations layers are stiff. It is believed to be the consequence of a build up of pore pressure due to the volumetric contraction of the dyke. On the other hand, soft foundation layers underwent large settlements which in turn deformed the stiff dyke without any slope failure taking place. However, diffused sheared zones were observed in the core of the dyke.

  4. An experimental investigation of dyke injection under regional extensional stress

    NASA Astrophysics Data System (ADS)

    Daniels, K. A.; Menand, T.

    2015-03-01

    Dyke injection is a fundamental process of magma transport in the crust, occurring in all tectonic settings. The effect of extensional stress regimes on dyke injections is particularly important to understanding a wide spectrum of processes including continental rifting and volcanic activity. Yet dyke injection in extensional regimes has been relatively understudied. In addition, the effect of dyke-dyke interaction modifying the surrounding stress field and leading to dyke rotation about the vertical axis has not been addressed. We present the results from 23 laboratory analogue experiments investigating lateral dyke injections in a remote extensional stress field. This study is unique in that it addresses the effect of both extension and dyke-dyke interaction on the lateral propagation and rotation of dykes. The experiments study the interrelationship between successive lateral dyke injections by examining dyke injection thickness, injection spacing, injection orientation, extension, and structural relationship. A relationship between the rotation angle between two successive intrusions and the distance separating them under given extensional stress conditions is established. The rotation angle depends on two dimensionless numbers: the ratio of fluid overpressure of the first injection and remote tensile stress, and the ratio of the spacing between injections and the height of the first intrusion. The experiments show how the stress field is perturbed by an intrusion and how the remote stress field is locally relieved by this intrusion. The results show furthermore that measuring or estimating the rotation angles between successive intrusions within rift zones allows the spatial distribution of these intrusions to be estimated. In the case of the actively spreading Red Sea rift in Afar, Ethiopia, we find that the vast majority of the dykes are predicted to intrude within 10 km of each other and most frequently between 4 and 5 km, in good agreement with independent

  5. Post-Arrival Health Screening in Karen Refugees in Australia

    PubMed Central

    Paxton, Georgia A.; Sangster, Katrina J.; Maxwell, Ellen L.; McBride, Catherine R. J.; Drewe, Ross H.

    2012-01-01

    Objective To document the prevalence of nutritional deficiencies, infectious diseases and susceptibility to vaccine preventable diseases in Karen refugees in Australia. Design Retrospective audit of pathology results. Setting Community based cohort in Melbourne over the period July 2006–October 2009. Participants 1136 Karen refugee children and adults, representing almost complete local area settlement and 48% of total Victorian Karen humanitarian intake for the time period. Main Outcome Measures Prevalence of positive test results for refugee health screening, with breakdown by age group (<6 years, 6–11 years, 12–17 years, 18 years and older). Results Overall prevalence figures were: anaemia 9.2%, microcytosis 19.1%, iron deficiency 13.1%, low vitamin B12 1.5%, low folate 1.5%, abnormal thyroid function tests 4.4%, vitamin D<50 nmol/L 33.3%, hypocalcaemia 7.4%, raised alkaline phosphatase 5.2%, abnormal liver transaminases 16.1%, hepatitis B surface antigen positive 9.7%, hepatitis B surface antibody positive 49.5%, isolated hepatitis B core antibody positive 9.0%, hepatitis C positive 1.9%, eosinophilia 14.4%, Schistosoma infection 7%, Strongyloides infection 20.8%, malaria 0.2%, faecal parasites 43.4%. Quantiferon-gold screening was positive in 20.9%. No cases of syphilis or HIV were identified. Serological immunity to vaccine preventable diseases was 87.1% for measles, 95% for mumps and 66.4% for rubella; 56.9% of those tested had seroimmunity to all three. Conclusions Karen refugees have high rates of nutritional deficiencies and infectious diseases and may be susceptible to vaccine preventable diseases. These data support the need for post-arrival health screening and accessible, funded catch-up immunisation. PMID:22693599

  6. Dyke-Davidoff-Masson syndrome: a clinicoradiological amalgam

    PubMed Central

    Sharma, Bhawna; Nagpal, Kadam; Handa, Rahul; Bhana, Indu

    2014-01-01

    Dyke-Davidoff-Masson syndrome is a relatively rare syndrome with its typical clinical and radiological features including facial asymmetry, hemiplegia, cerebral hemiatrophy, mental retardation with calvarial thickening, hypertrophy of sinuses and elevated petrous ridge on imaging. We present here a case of congenital type Dyke-Davidoff-Masson syndrome with some additional features in the form of microcephaly, hypospadias and pachygyria. PMID:24891488

  7. Mesoscale pervasive felsic magma migration: alternatives to dyking

    NASA Astrophysics Data System (ADS)

    Weinberg, Roberto F.

    1999-03-01

    This paper reviews the literature on dyking as a mechanism of felsic magma extraction from a source and transport to shallower crustal levels, and review the recent literature suggesting a range of alternative mechanisms of magma migration in hot crustal zones which produce mesoscale pervasive granite sheet intrusions. Recent papers have strongly favoured dyking as the main mechanism controlling magma migration. However, the initiation of dykes from a felsic magma source is fraught with difficulties, even when magma is immediately available for transportation, as in magma chambers. Within a partially molten source, magma may reside in a range of structures with a wide range of shapes, sizes and degrees of connectivity. Whereas the growth of individual dykes within a partially molten zone, and the self-propagation of large dykes into subsolidus crust, have both been studied in some detail, little attention has been given to the crucial intermediate step of the growth of a dyke network capable of producing wide crustal scale dykes. The rarity of granite dyke swarms suggests that, if dyking is the preferred mechanism of magma transport, felsic magma sources produce only few major transporting dykes during their lifetime. Alternatively, dyking is not an important mechanism. The parameters controlling the volume of the catchment drained by one such dyke, as well as other basic geometrical parameters controlling the structure of the dyke network within the source, are unknown. The ability of dyking to drain a partially molten source depends crucially on these variables and particularly on the horizontal permeability of the source. The slow velocity of viscous felsic magmas traveling in rock pores implies that magma drained during dyking is mostly that previously extracted from the pores, and resident in irregular magma bodies or dyke networks. The observation that large volumes of buoyant magma are commonly present in migmatite zones, and that dyking in these zones plays

  8. Quantifying crystal-melt segregation in dykes

    NASA Astrophysics Data System (ADS)

    Yamato, Philippe; Duretz, Thibault; May, Dave A.; Tartèse, Romain

    2015-04-01

    The dynamics of magma flow is highly affected by the presence of a crystalline load. During magma ascent, it has been demonstrated that crystal-melt segregation constitutes a viable mechanism for magmatic differentiation. However, the influences of crystal volume fraction, geometry, size and density on crystal melt segregation are still not well constrained. In order to address these issues, we performed a parametric study using 2D direct numerical simulations, which model the ascension of crystal-bearing magma in a vertical dyke. Using these models, we have characterised the amount of segregation as a function of different quantities including: the crystal fraction (φ), the density contrast between crystals and melt (Δρ), the size of the crystals (Ac) and their aspect ratio (R). Results show that crystal aspect ratio does not affect the segregation if R is small enough (long axis smaller than ~1/6 of the dyke width, Wd). Inertia within the system was also found not to influence crystal-melt segregation. The degree of segregation was however found to be highly dependent upon other parameters. Segregation is highest when Δρ and Ac are large, and lowest for large pressure gradient (Pd) and/or large values of Wd. These four parameters can be combined into a single one, the Snumber, which can be used to quantify the segregation. Based on systematic numerical modelling and dimensional analysis, we provide a first order scaling law which allows quantification of the segregation for an arbitrary Snumber and φ, encompassing a wide range of typical parameters encountered in terrestrial magmatic systems.

  9. The Role of Digital Literacy Practices on Refugee Resettlement: The Case of Three Karen Brothers

    ERIC Educational Resources Information Center

    Gilhooly, Daniel; Lee, Eunbae

    2014-01-01

    This study explores the social and cultural uses of digital literacies by adolescent immigrants to cope with their new lives in the United States. This case study focuses on three adolescent ethnic Karen brothers. Two years of participant observations in their home and Karen community, accompanied by formal and informal interviews, served as the…

  10. Assessment of the Psychosocial Development of Children Attending Nursery Schools in Karen Refugee Camps in Thailand

    ERIC Educational Resources Information Center

    Tanaka, Akiko

    2013-01-01

    The Karen, an ethnic minority group in Burma, have experienced a prolonged state of exile in refugee camps in neighboring Thailand because of ethnic conflict in their home country. Nursery schools in the three largest Karen refugee camps aim to promote the psychosocial development of young children by providing a child-centered, creative,…

  11. Researchers and the translational reality. Interview with Karen Aboody.

    PubMed

    Aboody, Karen

    2012-11-01

    Karen Aboody has first-hand experience of taking a potential therapy from the laboratory into clinical trials. Here, she shares with us the challenges and rewards of going from bench to bedside, and why all biomedical researchers need to know what it takes to make the transition if they want the best chance of seeing their discoveries used to help patients. Karen Aboody received her MD at Mount Sinai School of Medicine, and completed her post-doctoral training in Molecular Neurogenetics at Massachusetts General Hospital, Harvard Medical School. After gaining experience in pathology, gene therapy and biotechnology, she joined City of Hope (COH) in 2003 to head a translational research laboratory focused on therapeutic stem cell applications for invasive and metastatic solid tumors. In 2010, she received US FDA approval for a first-in-human clinical trial for neural stem cell-mediated therapy for high-grade glioma patients. This Phase I study is ongoing at COH, supported by NCI/NIH funding. In 2010, she received an US$18 million California Institute of Regenerative Medicine Disease Team Award to develop a second-generation enzyme/prodrug stem cell-mediated brain tumor therapy for clinical trials that may also have applications for other metastatic cancers. Honors include the 2000 AANS Young Investigator Award, and 2008 ASGCT Outstanding New Investigator Award. She recently founded a clinical-stage biopharmaceutical company, TheraBiologics Inc., to support clinical development of neural stem cell-mediated cancer therapies. PMID:23210812

  12. The propagation and seismicity of dyke injection, new experimental evidence

    NASA Astrophysics Data System (ADS)

    Bakker, Richard R.; Fazio, Marco; Benson, Philip M.; Hess, Kai-Uwe; Dingwell, Donald B.

    2016-03-01

    To reach the surface, dykes must overcome the inherent tensile strength of the country rock. As they do, they generate swarms of seismic signals, frequently used for forecasting. In this study we pressurize and inject molten acrylic into an encapsulating host rocks of (1) Etna basalt and (2) Comiso limestone, at 30 MPa of confining pressure. Fracture was achieved at 12 MPa for Etna basalt and 7.2 MPa for Comiso limestone. The generation of radial fractures was accompanied by acoustic emissions (AE) at a dominant frequency of 600 kHz. During "magma" movement in the dykes, AE events of approximately 150 kHz dominant frequency were recorded. We interpret our data using AE location and dominant frequency analysis, concluding that the seismicity associated with magma transport in dykes peaks during initial dyke creation but remains significant as long as magma movement continues. These results have important implications for seismic monitoring of active volcanoes.

  13. 1. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer June 1960 EXTERIOR OF THE SOUTH AND EAST ELEVATIONS - The Judges Law Office, 100 West Market Street, Georgetown, Sussex County, DE

  14. 1. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 FRONT ELEVATION - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  15. 2. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 DETACHED KITCHEN - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  16. 6. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 DINING ROOM (PRESENT KITCHEN) WITH STAIR AND DOORS TO PARLOR (LEFT) AND BEDROOM - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  17. 3. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 MAIN STAIR FROM FIRST FLOOR - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  18. 5. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 FIREPLACE AND CUPBOARD IN PARLOR - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  19. 4. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey Cortlandt Van Dyke Hubbard, Photographer February 1961 PANELING UNDER WINDOW IN PARLOR - Baynard House, Lewis Road (moved to MD-Chesapeake City Vicinity), Harrington, Kent County, DE

  20. Giant radiating dyke swarms on Earth and Venus

    NASA Astrophysics Data System (ADS)

    Ernst, R. E.; Head, J. W.; Parfitt, E.; Grosfils, E.; Wilson, L.

    1995-09-01

    Concentrations of dykes of basic composition emplaced in the same igneous episode or along similar trends are known as mafic dyke swarms and they occur in a wide variety of environments and over a wide range of scales on Earth. Recent radar mapping of Venus has revealed families of linear features interpreted to be the surface expression of near-surface dyke swarms. The lack of significant erosion on Venus provides a view of the surface manifestation of dyke swarm emplacement, one which complements the terrestrial perspective of erosion to deeper levels. The goal of this review is to synthesize the information available on both planets in order to use the complementary and synergistic record of mafic dyke swarm emplacement to build toward a better understanding of this important phenomenon in planetary history. We focus on the formation and evolution of giant dyke swarms which cover tens to hundreds of thousands of square kilometres on both Earth and Venus. Mafic dyke swarms on Earth occur in a wide range of modes and are observed in environments ranging from volcanic edifices (e.g., Hawaii), to central complexes (e.g., Spanish Peaks Complex, USA; Ramon Swarm, Israel), spreading centres and ophiolite complexes, compressional plate boundaries in back-arc settings (Columbia River Basalts, USA) and in continent-continent collisions. One of the most impressive modes of occurrence is that linked to the formation and evolution of mantle plumes. Terrestrial examples include a giant radiating swarm covering 100° of azimuth (the Mackenzie swarm, Canada), a 360° giant radiating swarm (the Central Atlantic reconstructed swarm), deformed giant radiating swarms (the Matachewan swarm, Canada), rift-arm associated swarms (e.g., Grenville swarm, Canada; Yakutsk swarm, Siberia), and one consisting of widely separated dykes (e.g., the Abitibi swarm, Canada). We summarize the geometric, chemical and isotopic characteristics of terrestrial dyke swarms, including their size and

  1. "Can I Ask That?": Perspectives on Perinatal Care After Resettlement Among Karen Refugee Women, Medical Providers, and Community-Based Doulas.

    PubMed

    LaMancuso, Kate; Goldman, Roberta E; Nothnagle, Melissa

    2016-04-01

    This study characterized the perspectives of Karen refugee women in Buffalo, NY, their medical providers, and Karen interpreters/doulas on perinatal care for Karen women in resettlement. In-depth qualitative interviews with Karen women (14), Karen doulas/interpreters and key informants (8), and medical providers (6) were informed by the social contextual model and focused on women's questions about and opinions of perinatal care in Buffalo and on providers' experiences caring for Karen patients. Karen women expressed gratitude for and understanding of perinatal care in Buffalo, and providers described Karen patients as agreeable but shy. Karen doulas offered an alternative view that exposed women's many questions and concerns, and described how doula training empowered them as patients' advocates. Low self-efficacy, trauma histories, and cultural expectations may contribute to Karen women's seeming agreeability. Doulas/interpreters possess insider knowledge of women's concerns and facilitate communication between patients and the care team. PMID:25724151

  2. Weibull-distributed dyke thickness reflects probabilistic character of host-rock strength.

    PubMed

    Krumbholz, Michael; Hieronymus, Christoph F; Burchardt, Steffi; Troll, Valentin R; Tanner, David C; Friese, Nadine

    2014-01-01

    Magmatic sheet intrusions (dykes) constitute the main form of magma transport in the Earth's crust. The size distribution of dykes is a crucial parameter that controls volcanic surface deformation and eruption rates and is required to realistically model volcano deformation for eruption forecasting. Here we present statistical analyses of 3,676 dyke thickness measurements from different tectonic settings and show that dyke thickness consistently follows the Weibull distribution. Known from materials science, power law-distributed flaws in brittle materials lead to Weibull-distributed failure stress. We therefore propose a dynamic model in which dyke thickness is determined by variable magma pressure that exploits differently sized host-rock weaknesses. The observed dyke thickness distributions are thus site-specific because rock strength, rather than magma viscosity and composition, exerts the dominant control on dyke emplacement. Fundamentally, the strength of geomaterials is scale-dependent and should be approximated by a probability distribution. PMID:24513695

  3. Weibull-distributed dyke thickness reflects probabilistic character of host-rock strength

    PubMed Central

    Krumbholz, Michael; Hieronymus, Christoph F.; Burchardt, Steffi; Troll, Valentin R.; Tanner, David C.; Friese, Nadine

    2014-01-01

    Magmatic sheet intrusions (dykes) constitute the main form of magma transport in the Earth’s crust. The size distribution of dykes is a crucial parameter that controls volcanic surface deformation and eruption rates and is required to realistically model volcano deformation for eruption forecasting. Here we present statistical analyses of 3,676 dyke thickness measurements from different tectonic settings and show that dyke thickness consistently follows the Weibull distribution. Known from materials science, power law-distributed flaws in brittle materials lead to Weibull-distributed failure stress. We therefore propose a dynamic model in which dyke thickness is determined by variable magma pressure that exploits differently sized host-rock weaknesses. The observed dyke thickness distributions are thus site-specific because rock strength, rather than magma viscosity and composition, exerts the dominant control on dyke emplacement. Fundamentally, the strength of geomaterials is scale-dependent and should be approximated by a probability distribution. PMID:24513695

  4. The Case of Three Karen Refugee Women and Their Children: Literacy Practices in a Family Literacy Context

    ERIC Educational Resources Information Center

    Quadros, Sabrina; Sarroub, Loukia K.

    2016-01-01

    The lack of research about the Karen, one of 135 ethnic groups from Myanmar limits literacy educators charged with educating this refugee population in public schools. In this case study the authors explore the literacy practices of Karen families when at school and in their homes and within an ESL family literacy program. The case of these…

  5. Dyke emplacement and propagation: a new laboratory approach

    NASA Astrophysics Data System (ADS)

    Bakker, R.; Benson, P.; Vinciguerra, S.

    2013-12-01

    It is well known that magma ascends trough the crust by the process of dyking. During dyke movement crustal rocks, specifically the volcano's basement rocks, fracture due to the stress imposed by the ascending magma, thus providing conduits for magma transport. Dykes are frequently seen in the field and have been reproduced via numerical and analogue studies. However, a number of assumptions regarding rock mechanical behavior frequently has to be made as such data are very hard to directly measure at the pressure/temperature conditions of interest: high temperatures at relatively shallow depths. Such data are key to simulating the magma intrusion dynamics through the lithologies that underlie the volcanic edifice. To bridge this gap, we have performed a suite of rock deformation experiments in both compressive and tensile regimes, using a Paterson-type triaxial apparatus on representative lithologies present in the basement of Mt. Etna. In the compressive regime, we find that sedimentary rocks present at a depth of aproximately 2 km show a B/D transition at around 300 degC and significant weakening with temperatures exceeding 400 degC. Volcanic rocks (basalt) shows a significant change in deformation behavior only at temperatures exceeding 800 degC. Such a large contrast in mechanical properties could be favorable for dyke deflection or dyke arrest. However, in the tensile regime, it remains a significant technical challenge to precisely reproduce the conditions of dyking in the lab. As a starting point, we are now testing an analogue material to replace the magma to avoid such high temperatures, relying of maintaining similar temperature/viscosity ratios between magma/country rock in the laboratory and the field. We chose PMMA (a.k.a. plexiglass) for this task as it displays a large range in viscosities (log(visc)range = 10 - 1) with temperatures between 100 and 300 degC, making it an excellent analogue material. In addition PMMA solidifies after the sample cools

  6. Geochemistry of eastern North American CAMP diabase dykes

    NASA Astrophysics Data System (ADS)

    Callegaro, S.; Marzoli, A.; Bertrand, H.; Reisberg, L. C.; Chiaradia, M.; Bellieni, G.

    2011-12-01

    The Piedmont area of the Appalachians and the coastal plains of eastern North America (ENA) were intruded between 202 and 195 Ma[1,2] by swarms of diabase (dolerite) dykes and a few sills of the Central Atlantic magmatic province (CAMP). Different trends are observed for the dykes, from NW (more frequent in the South), to N-S and NE, thus a radial pattern and a coeval emplacement driven by the bulging effect of a mantle plume were initially inferred[3]. Conversely, based on field data, an age progression can be defined from NW- to N- and NE-oriented dykes, supporting a diachronous northward rift-to-drift transition during Pangaea break-up. New geochemical data on 74 ENA dykes suggest a dominant lithospheric mantle source for these magmatic suite. A deep enriched mantle source is further discarded by the crystallization temperatures (ca.1350°C) calculated[4] for high-Fo (up to Fo89) olivines, which do not reflect very hot (i.e. mantle-plume) potential mantle temperatures. Incompatible trace element contents are fairly homogeneous and generally low, e.g. (La/Yb)Ch (0.54-2.39), typical of melts derived from a quite depleted shallow (spinel) mantle-source. However, isotopic compositions of ENA dykes display a considerable spread in initial isotopic signatures, do not show correlation with incompatible trace elements, and are independent of the orientation and age of the dykes, i.e. 87Sr/86Sr200Ma (0.7043-0.7088), ɛNd200Ma (-6.67-+2.42) and 206Pb/204Pb200Ma (17.46-18.61). Pb isotopic compositions plot above the NHRL, at positive Δ7/4 (10-17) and Δ8/4 (19-73), calling for an enriched ancient component in the mantle source. Unradiogenic 187Os/188Os200Ma ratios (0.127-0.144) argue for negligible amounts of crustal contamination and, coupled with the large range of Sr-Nd-Pb isotopic compositions, suggest generation from a strongly heterogeneous mantle source, probably metasomatized lithosphere. Lithospheric mantle underlying the Appalachian orogen may have undergone

  7. Dyke and sill injections: what mostly trigger volcano flank collapse?

    NASA Astrophysics Data System (ADS)

    Catry, Thibault; Cayol, Valérie; Michon, Laurent; Famin, Vincent; Romagnoli, Claudia; Chaput, Marie

    2010-05-01

    There is a large number of evidences that the morphostructural evolution of basaltic oceanic volcanoes (e.g. Stromboli, Hawaï and Canary Islands) results of alternating phases of growth and destruction. Among dismantling processes, flank collapses have been largely documented and interpreted as gravitational destabilization triggered by vertical injections of magma (dykes). In most cases, this interpretation has not been sustained by field observations because active volcanoes have poor occurrence of outcropped intrusions. From this point of view, Piton des Neiges volcano (La Réunion Island) represents a case in point because it has been deeply incised by erosion, providing large outcropped surfaces exhibiting the geometrical relationship between intrusions and host volcanic formations. The recent discovery of a highly deformed pile of sills at the interface between a debris avalanche deposit and a fossilized magma chamber brought to light the role of horizontal injections in the triggering of lateral collapses. The validation of this assumption rests on a digital model developed from the Mixed Boundary Element Method of elastic deformation field analysis. In this study, we modelled the intensity and the distribution of deformation and Coulomb stresses perturbation due to the injection of dykes along rift zones and a sill below the flank of a basaltic volcano. We quantified the influence of the intrusions in the mechanical state of the edifice, based on the deformation detected during an intrusion of magma at Piton de la Fournaise volcano. By comparing the deformation generated by sills to that generated by dykes, our modelling approach concludes that the area deformed by a sill injection is much wider than that deformed by a dyke injection. Moreover, we found that sill injection reaches higher intensities of lateral displacements. The combination of field data and our modelling results suggests therefore that repeated sill injection is an underestimated trigger

  8. Permanent groundwater storage in basaltic dyke fractures and termite mound viability

    NASA Astrophysics Data System (ADS)

    Mège, Daniel; Rango, Tewodros

    2010-04-01

    Many basaltic dykes of the Ethiopian flood basalt province are observed in the northwestern Ethiopian lowlands. In this area, the termites preferentially build their epigeous mounds on the top of dolerite dykes. The relationship between termite mounds and dykes is investigated from the analysis of their distribution along one of these dykes, of thickness 2-5 m, that we could follow over 2000 m. Termite mounds are periodically spaced (mean distance 63 m, R2 = 0.995), and located exclusively where the topographic relief of the dyke is not more than 2 m above the surrounding area. From these observations and from the geological context, a hydrological circuit model is proposed in which (1) dykes are preferential conduits for groundwater drainage during the rainy season due to pervasive jointing, (2) during the dry season, the portion of the dyke forming a local topographic relief area dries up more quickly than the surroundings, the elevation difference between the dyke summit and the surroundings being a factor restricting termite mound development. For dyke topographic relief >2 m, drying is an obstacle for maintaining the appropriate humidity for the termite colony life. Periodic termite mound spacing is unlikely to be related to dyke or other geological properties. It is more likely related to termite population behaviour, perhaps to clay shortage, which restricts termite population growth by limiting the quantity of building material available for mound extension, and triggers exploration for a new colonization site that will be located along the dyke at a distance from the former colony that may be controlled by the extent of the zone covered by its trail pheromones. This work brings out the importance of dykes in channelling and storing groundwater in semiarid regions, and shows that dykes can store groundwater permanently in such settings even though the dry season is half the year long. It contributes also to shedding light on water supply conditions

  9. Seismic footprints of shallow dyke propagation at Etna, Italy

    PubMed Central

    Falsaperla, Susanna; Neri, Marco

    2015-01-01

    One of the key issues in forecasting volcanic eruptions is to detect signals that can track the propagation of dykes towards the surface. Continuous monitoring of active volcanoes helps significantly in achieving this goal. The seismic data presented here are unique, as they document surface faulting processes close (tens to a few hundred meters) to their source, namely the dyke tip. They originated nearby - and under - a seismic station that was subsequently destroyed by lava flows during eruptive activity at Etna volcano, Italy, in 2013. On February 20, a ~600 m-long and ~120 m wide NW-SE fracture field opened at an altitude between 2750 and 2900 m. The consequent rock dislocation caused the station to tilt and offset the seismic signal temporarily. Data acquisition continued until the arrival of the lava flow that led to the breakdown of the transmission system. Shallow ground fracturing and repeated low-frequency oscillations occurred during two stages in which the seismic signal underwent a maximum offset ~2.57 × 104 nm/s. Bridging instrumental recordings, fieldwork and conceptual modelling, these data are interpreted as the seismic footprints of a magmatic dyke intrusion that moved at speed ~0.02 m/s (first stage) and 0.46 m/s (second stage). PMID:26173557

  10. Seismic footprints of shallow dyke propagation at Etna, Italy.

    PubMed

    Falsaperla, Susanna; Neri, Marco

    2015-01-01

    One of the key issues in forecasting volcanic eruptions is to detect signals that can track the propagation of dykes towards the surface. Continuous monitoring of active volcanoes helps significantly in achieving this goal. The seismic data presented here are unique, as they document surface faulting processes close (tens to a few hundred meters) to their source, namely the dyke tip. They originated nearby - and under - a seismic station that was subsequently destroyed by lava flows during eruptive activity at Etna volcano, Italy, in 2013. On February 20, a ~600 m-long and ~120 m wide NW-SE fracture field opened at an altitude between 2750 and 2900 m. The consequent rock dislocation caused the station to tilt and offset the seismic signal temporarily. Data acquisition continued until the arrival of the lava flow that led to the breakdown of the transmission system. Shallow ground fracturing and repeated low-frequency oscillations occurred during two stages in which the seismic signal underwent a maximum offset ~2.57 × 10(4) nm/s. Bridging instrumental recordings, fieldwork and conceptual modelling, these data are interpreted as the seismic footprints of a magmatic dyke intrusion that moved at speed ~0.02 m/s (first stage) and 0.46 m/s (second stage). PMID:26173557

  11. Dyke emplacement at the incipient Namibian margin - structural and anisotropy of magnetic susceptibility (AMS) studies in the Henties Bay - Outjo Dyke Swarm

    NASA Astrophysics Data System (ADS)

    Wiegand, Miriam; Trumbull, Robert; Greiling, Reinhard O.

    2010-05-01

    During the Cretaceous breakup of western Gondwana, the conjugate Namibian and South American margins were the site of flood basalts, mafic dyke swarms and subvolcanic intrusive complexes which make up the South Atlantic Large Igneous Province and the volcanic margin of northwestern Namibia. This contribution presents data on internal fabrics in mafic dykes (mostly subalkaline tholeiitic dolerites) from the major Henties Bay-Outjo dyke swarm (HOD) in coastal and inland NW Namibia, which are discussed in terms of magma emplacement. The HOD is some 100 km wide and extends at least 500 km from the continental margin. The dykes were emplaced in Neoproterozoic (Panafrican) Damara mobile belt, which is bounded by the Angola/Congo craton on the north and the Kalahari craton on the south. Field relations and radiometric dates indicate Early Cretaceous emplacement ages for the dykes. In coastal exposures north of the HOD, dolerite dykes are mainly coast-parallel (NNW-SSE) and syn-tectonic with normal faults that offset Etendeka lavas. Coast-parallel dykes are also common within the HOD, but the great majority of dykes strike NE-SW. We observed the latter dykes to crosscut coast-parallel ones. But the opposite relationship is also found locally. The dominant NE-SW strike of HOD indicates the influence of the Damara Belt structural grain at a regional scale, but locally the dykes commonly crosscut basement foliations and lithologic contacts. Depending on dyke thickness, which varies in the HOD from a few cm to about 50 m), the dykes are variably fine grained with chilled margins. Vesiculation is seldom observed. Typical textures are intersertal to subophitic, with plagioclase, clinopyroxene and olivine being the main mineral phases. Common minor minerals include opaque oxides and acicular apatite. Linear dykes are composed of segments, 10 m to some km in length, which are connected by transfer zones. Often a minor horizontal displacement can be observed between these segments

  12. Giant radiating dyke swarms on Earth and Venus

    NASA Technical Reports Server (NTRS)

    Ernst, Richard E.; Head, James W.; Parfitt, Elisabeth; Wilson, Lionel; Grosfils, Eric

    1993-01-01

    On Earth, giant radiating dyke swarms are usually preserved as fan-shaped fragments which have been dismembered from their original configuration by subsequent plate tectonic rifting events. Analysis of the largest fragments and consideration of their original configuration has led to the idea that many swarms are plume related, and that dyke swarms radiate away from plume centers. Magellan radar data reveal abundant intact giant radiating swarms on Venus which are similar in scale and pattern to those on Earth. The absence of intense weathering and plate tectonic processes on Venus accounts for the preservation of the primary radiating patterns. It is characteristic of both Earth and Venus that giant radiating dikes are emplaced laterally for distances of at least 2000 km away from plume centers. At distances beyond the influence of the plume on both Earth and Venus, the radiating dyke pattern is often swept into a linear pattern aligned with the regional stress field. There is tremendous potential synergism between the characterization and analysis of terrestrial dyke swarms (where significant erosion has revealed their structure and emplacement directions at depth) and the giant swarms of Venus (where the complete circumferential structure is preserved, and the surface fracture systems above near surface dikes and the nature of the central source regions are revealed). In this study, we report on the characteristics of radial dyke swarms on Earth and Venus and draw some preliminary comparisons from the two perspectives. In summary, on both planets there is evidence for plume-related magmatic centers associated with vertical and lateral injection of magma over considerable distances (up to at least 2000 km). The abundance of very broadly radiating swarms on Venus supports the notion that the swarms on Earth were radiating over broad sectors at the time of intrusion but were dissected by later events. The Venus data show that a swarm can change from radiating

  13. An Education Rooted in Two Worlds: The Karen of Northern Thailand

    ERIC Educational Resources Information Center

    Odochao, Jonni; Nakashima, Douglas; Vaddhanaphuti, Chayan

    2006-01-01

    In Karen culture, the family is traditionally the basic unit for the education of the child. In the early 1970s, when Jonni Odochao began to notice that children could not relate to their elders or respect them, he surmised that the problem stemmed from the modern education system and its increasing influence upon youth values, behaviour and ways…

  14. Engaged Teaching and Learning with Adult Karen Refugees in a Service-Learning Site

    ERIC Educational Resources Information Center

    Smolen, Lynn Atkinson; Zhang, Wei; Detwiler, Stephen

    2013-01-01

    This article describes a case study of a service-learning project connected to a TESOL (teaching English to speakers of other languages) teacher preparation program. The case study explored the teacher candidates' experiences teaching English to Karen refugees from Myanmar (Burma) in a midwestern city in the United States. The teacher…

  15. Unbalanced Nature, Unbounded Bodies, and Unlimited Technology: Ecocriticism and Karen Traviss' Wess'har Series

    ERIC Educational Resources Information Center

    Sullivan, Heather I.

    2010-01-01

    While nature is often claimed to be a space of harmonized balance or an antidote to the chaos of the modern world, we need a more grounded assessment of nature as endlessly changing and much less predictable than we like to assume. In this essay, I explore Karen Traviss' provocative exploration of unbalanced nature and unbounded bodies in her…

  16. The influence of administrative leadership: an interview with Dr Karen S. Hill.

    PubMed

    Hill, Karen S; Adams, Jeffrey M

    2015-01-01

    This department highlights nursing leaders who have demonstrated a commitment to patient care leadership and innovation in practice, policy, research, education, and theory. This interview profiles Karen Hill, DNP, RN, NEA-BC, FACHE, FAAN, chief operating officer and chief nursing officer of Baptist Health in Lexington, Kentucky, and editor-in-chief of the Journal of Nursing Administration. PMID:25479168

  17. Newbery Medal Winner Karen Hesse Brings Billie Jo's Voice "Out of the Dust."

    ERIC Educational Resources Information Center

    Hendershot, Judy; Peck, Jackie

    1999-01-01

    Describes an interview with children's author Karen Hesse, discussing such things as how she chose writing as a career, her use of figurative language and her skillful crafting of dialog, where her book ideas come from, and her latest projects. (SR)

  18. Geological consequences of the Saemangeum Dyke, mid-west coast of korea: A review

    NASA Astrophysics Data System (ADS)

    Lee, Hee Jun; Lee, Soo Hwan

    2012-12-01

    The Saemangeum Dyke is located in an estuarine setting, regulated in a complicated manner by a macrotidal regime, rivers, and winter monsoon. Accordingly, the constructed dyke resulted in a variety of artificial changes in geological characteristics in the estuary and its vicinity. To investigate those dyke-induced changes, the KORDI (Korea Ocean Research and Development Institute) performed sedimentological and sediment-dynamical observations from 2002 to 2010. On the basis of the KORDI results, the major geological changes and associated dynamical processes are reviewed. Five phenomena, among others, are focused on: depositional-channel creation; gap-related erosion; forced movements of surface sands; tidal-flat growth inside the dyke; and blanketing of mud over the sandy seafloor. These phenomena were unforeseen before the dyke construction, and reflect that the dyke could cause both erosion and deposition on an estuarine scale. The investigations conclude that the sediments in the dyke-influenced region were derived from the two rivers, Mangyeong and Dongjin, of the estuary. This is completely contrary to the offshore origin proposed before the dyke construction. As a result, the review supports the proposal that a thorough geological investigation and rational forecast is necessary prior to dyke construction to avoid economic loss and a fractious environmental debate.

  19. Dyke Monitorin by the Means of Persistent Scattering Interferometry at the Coast of Northern Germany

    NASA Astrophysics Data System (ADS)

    Seidel, M.; Marzahn, P.; Ludwig, R.

    2016-06-01

    40 percent of the world's population are presently living in coastal areas or along the main rivers. Taking into account that the vulnerability of these areas is increasing due to sea-level rise and coastal hazards such as storm surges or extreme rainfall events accompanied with floods, the importance of safety structures such as dykes is increasing as well. Hence, a spatial distributed dyke monitoring should be part of a sustainable adaptation strategy. Due to increasing amount of SAR-data from various satellites with high spatial and temporal coverage, the means of SAR-interferometry could be an essential tool to ensure this kind of required monitoring. Given this prospect, Persistent Scattering Interferometry (PSI) will be a very suitable monitoring technique for dyke structures to identify dyke movement with the accuracy of few millimetres. This procedure focuses on pixels that show a stable scattering behaviour in a sequence of multiple SAR-scenes. In opposition to ground-measurements, the spatial coverage of this technique provides comparable results for different parts of the dyke; furthermore weak segments with particular high movements could be identified in advance. This could prevent future dyke crevasses and help to reduce risks in high-populated areas. This paper attempts to describe the potential of the PSI technique for a spatial distributed dyke monitoring at the coast in northern Germany. 21 ERS-2 scenes and 16 Envisat ASAR scenes were analysed. Those Scenes cover an area of a sea shore dyke including a flood regulation barrage and results point out the potential for this technique to monitor dyke structures. Even though the observed dyke doesn't show any significant deformation rates, the two datasets show the same signal for the whole dyke.

  20. Fault-related carbonate breccia dykes in the La Chilca area, Eastern Precordillera, San Juan, Argentina

    NASA Astrophysics Data System (ADS)

    Castro de Machuca, Brígida; Perucca, Laura P.

    2015-03-01

    Carbonate fault breccia dykes in the Cerro La Chilca area, Eastern Precordillera, west-central Argentina, provide clues on the probable mechanism of both fault movement and dyke injection. Breccia dykes intrude Upper Carboniferous sedimentary rocks and Triassic La Flecha Trachyte Formation. The timing of breccia dyke emplacement is constrained by cross cutting relationships with the uppermost Triassic unit and conformable contacts with the Early Miocene sedimentary rocks. This study supports a tectonic-hydrothermal origin for these breccia dykes; fragmentation and subsequent hydraulic injection of fluidized breccia are the more important processes in the breccia dyke development. Brecciation can be triggered by seismic activity which acts as a catalyst. The escape of fluidized material can be attributed to hydrostatic pressure and the direction of movement of the material establishes the direction of least pressure. Previous studies have shown that cross-strike structures have had an important role in the evolution of this Andean segment since at least Triassic times. These structures represent pre-existing crustal fabrics that could have controlled the emplacement of the dykes. The dykes, which are composed mostly of carbonate fault breccia, were injected upward along WNW fractures.

  1. The Aiguablava dyke swarm: emplacement and paleostress in a fractured basement

    NASA Astrophysics Data System (ADS)

    Martínez-Poza, Ana Isabel; Druguet, Elena; Castaño, Lina Marcela; Carreras, Jordi

    2013-04-01

    A structural analysis has been performed in the Upper Permian lamprophyric dyke swarm of Aiguablava (NE Spain). Dyke emplacement is related to the presence of a widespread joint network, likely developed during the cooling and decompression of the late Variscan granitic host rocks. In order to characterize the patterns of both the joint system and the dyke swarm, a trend frequency analysis has been performed using the circular scanlines method (Mauldon et al., 2001). The sub-vertical joint pattern consists on two major orthogonal sets at ≈N23°, ≈N113° and secondary sets at ≈N0° and ≈N90°, among others. These four fracture sets are interpreted as previous to the lamprophyre intrusion event, because they are either exploited or cross-cut by the lamprophyres. The subvertical dykes have a mean N113° trend, which corresponds to the trend of one of the main joint sets. Despite this overall orientation of dykes, segmentation is a noticeable feature at the Dm- to cm-scale, and this is probably related to the localized dyke intrusion into the other pre-existing secondary joint sets. Dyke opening directions has been measured from matching dyke jogs or markers in the host rock, with a mean orientation of 021/04. A three-dimensional paleostress analysis has been carried out from dyke orientations, applying the Mohr circle construction of Jolly and Sanderson (1997), and the parameters R' (driving pressure ratio, R'= 0.156) and φ (stress ratio, φ = 0.45) were calculated. From this analysis, we have obtained a sub-vertical maximum (σ1) and a NNE-SSW minimum (σ3) stress axes, consistent with the sub-horizontal mean trend of dyke opening measured in the field. It is inferred that many of the pre-existing joint sets were exploited by magmatic dykes, being the ≈N113° joint set (normal to σ3) the most favourable for dyke emplacement. At that time, magmatic pressure related to dyke intrusion, Pm, was lower than the intermediate principal stress axis, σ2 . Our

  2. Microstructural indicators of convection in sills and dykes

    NASA Astrophysics Data System (ADS)

    Holness, Marian; Neufeld, Jerome; Gilbert, Andrew

    2016-04-01

    . In mafic sills, the average apparent aspect ratio (AR), as measured in thin-section, varies smoothly with model crystallization times (calculated assuming diffusive heat loss), consistent with in situ growth in solidification fronts. However, AR is invariant across individual mafic dykes, with decreasing values (i.e. more blocky grains) as the dyke width increases. This difference can be accounted for by the plagioclase in dykes growing as individual grains and clusters suspended in a convecting magma. Cooling at a vertical wall, as is the case for dykes, will always result in a gravitational convective instability, and therefore crystal-poor magma in dykes will always convect. As solidification proceeds, the increasing volume fraction of suspended crystals will eventually damp convection: the final stages of solidification occur in static crystal-rich magma, containing a well-mixed grain population. That the Shiant Isles Main Sill exhibits evidence for prolonged convection of sufficient vigour to suspend 5 mm olivine clusters, while other sills of comparable thickness contain plagioclase with grain shapes indicative of growth predominantly in solidification fronts, is most likely due to the composite nature of the Shiant. The 140m unit is underlain by 23m of picrite which intruded shortly before - this heat source would have acted as a strong driver for convection.

  3. Partners in a Great Adventure: Karen Bersche--Alliance Library System, East Peoria, IL

    ERIC Educational Resources Information Center

    Library Journal, 2005

    2005-01-01

    As early as junior high school, after she had gone to see The Music Man and came out idolizing Marian, Karen Bersche knew she was destined for librarianship. But she didn't get around to it until after she got a degree in counseling, started her family, and opened her own daycare center. She has more than made up for lost time since, first as…

  4. The application aeromagnetic data for dyke swarm mapping (an example the Ladoga region, Russia)

    NASA Astrophysics Data System (ADS)

    Vasilieva, T.; Frank-Kamenetsky, D.

    2003-04-01

    Vasilieva T.I., Frank-Kamenetsky D.A., Zayonchek A.V. The main factor of the Fennoscandian evolution in Late Proterozoic was inter- and intracratonic rifting. However, products of magmatic activity were removed by erosion. Thus, only plutonic bodies and dyke swarms allow us to reconstruct the Fennoscandian shield tectono-magmatic evolution in Late Proterozoic. The rifting processes in southeastern Fennoscandia took place in Riphean. The earlier are several massifs of rapakivi-granite accompanied by mafic dyke swarms with age about 1.64 to 1.51 Ga were formed. The Middle Riphean is characterized by rift structure forming. They are known in Russia (White Sea rift system, northern Kola, Ladoga Lake, probably, Onega Lake), Finland (Muhos, Satakunta) and central Sweden. The age of mafic magmatic complexes, corresponding with these rift systems, is 1.24 Ga (Suominen, 1991). There are at least two stages of Riphean evolution and magmatic complexes in Ladoga Lake region. They are the Salminski and Vyborg rapakivi-granites at first, Salminski volcano-sedimentary suite, Valaam sill, Hopunvaara intrusion and several dolerites dykes at second. Our detailed studies based on magnetic geophysical data. A combination of geophysical methods and GIS provided effective mapping of dyke swarms in NW Ladoga. It has shown that the Fe-enriched olivine dolerite dykes, it was described on the NW coast of Ladoga Lake, are very locally developed forming narrow zone, which runs through Sortavala town and several islands. The dykes were clearly observed, because of their extremely high magnetic susceptibility. The dykes strike toward NW corresponding to the longest axis of the graben. Chemical identity of the dykes and Salminski lavas allows considering the age of this rifting about 1.35 Ga. The other dyke complexes were being described in North-West Ladoga region. It is dykes of fresh clinopyroxene dolerites. Probably, the dykes are accompanying by rapakivi-granites. Unfortunately, very

  5. Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, Iceland.

    PubMed

    Sigmundsson, Freysteinn; Hooper, Andrew; Hreinsdóttir, Sigrún; Vogfjörd, Kristín S; Ófeigsson, Benedikt G; Heimisson, Elías Rafn; Dumont, Stéphanie; Parks, Michelle; Spaans, Karsten; Gudmundsson, Gunnar B; Drouin, Vincent; Árnadóttir, Thóra; Jónsdóttir, Kristín; Gudmundsson, Magnús T; Högnadóttir, Thórdís; Fridriksdóttir, Hildur María; Hensch, Martin; Einarsson, Páll; Magnússon, Eyjólfur; Samsonov, Sergey; Brandsdóttir, Bryndís; White, Robert S; Ágústsdóttir, Thorbjörg; Greenfield, Tim; Green, Robert G; Hjartardóttir, Ásta Rut; Pedersen, Rikke; Bennett, Richard A; Geirsson, Halldór; La Femina, Peter C; Björnsson, Helgi; Pálsson, Finnur; Sturkell, Erik; Bean, Christopher J; Möllhoff, Martin; Braiden, Aoife K; Eibl, Eva P S

    2015-01-01

    Crust at many divergent plate boundaries forms primarily by the injection of vertical sheet-like dykes, some tens of kilometres long. Previous models of rifting events indicate either lateral dyke growth away from a feeding source, with propagation rates decreasing as the dyke lengthens, or magma flowing vertically into dykes from an underlying source, with the role of topography on the evolution of lateral dykes not clear. Here we show how a recent segmented dyke intrusion in the Bárðarbunga volcanic system grew laterally for more than 45 kilometres at a variable rate, with topography influencing the direction of propagation. Barriers at the ends of each segment were overcome by the build-up of pressure in the dyke end; then a new segment formed and dyke lengthening temporarily peaked. The dyke evolution, which occurred primarily over 14 days, was revealed by propagating seismicity, ground deformation mapped by Global Positioning System (GPS), interferometric analysis of satellite radar images (InSAR), and graben formation. The strike of the dyke segments varies from an initially radial direction away from the Bárðarbunga caldera, towards alignment with that expected from regional stress at the distal end. A model minimizing the combined strain and gravitational potential energy explains the propagation path. Dyke opening and seismicity focused at the most distal segment at any given time, and were simultaneous with magma source deflation and slow collapse at the Bárðarbunga caldera, accompanied by a series of magnitude M > 5 earthquakes. Dyke growth was slowed down by an effusive fissure eruption near the end of the dyke. Lateral dyke growth with segment barrier breaking by pressure build-up in the dyke distal end explains how focused upwelling of magma under central volcanoes is effectively redistributed over long distances to create new upper crust at divergent plate boundaries. PMID:25517098

  6. Refractory Seizure in Childhood: Dyke-Davidoff-Masson Syndrome Revisited.

    PubMed

    Dutta, Abhijit; Bose, Sagar; Sen, Kaushik; Pandit, Narayan; Sharma, Samarth

    2016-07-01

    Dyke-Davidoff-Masson syndrome (DDMS) is a rare disorder characterized by recurrent seizures, facial asymmetry, contralateral hemiplegia, radiologic features of cerebral hemiatrophy, and ipsilateral compensatory hypertrophy of the skull bone and sinuses. We describe three cases of children with DDMS, who initially presented with refractory seizure to the pediatric department of North Bengal Medical College and Hospital, India. In each case, the clinical features noted along with computed tomography or magnetic resonance imaging helped confirm the diagnosis of DDMS. DDMS should be considered as a differential diagnosis of refractory seizures in children. We seek to emphasize the importance of thorough clinical and neuroimaging workup of seizure disorder in children for the proper management of the condition. PMID:27403244

  7. Refractory Seizure in Childhood: Dyke-Davidoff-Masson Syndrome Revisited

    PubMed Central

    Dutta, Abhijit; Bose, Sagar; Sen, Kaushik; Pandit, Narayan; Sharma, Samarth

    2016-01-01

    Dyke-Davidoff-Masson syndrome (DDMS) is a rare disorder characterized by recurrent seizures, facial asymmetry, contralateral hemiplegia, radiologic features of cerebral hemiatrophy, and ipsilateral compensatory hypertrophy of the skull bone and sinuses. We describe three cases of children with DDMS, who initially presented with refractory seizure to the pediatric department of North Bengal Medical College and Hospital, India. In each case, the clinical features noted along with computed tomography or magnetic resonance imaging helped confirm the diagnosis of DDMS. DDMS should be considered as a differential diagnosis of refractory seizures in children. We seek to emphasize the importance of thorough clinical and neuroimaging workup of seizure disorder in children for the proper management of the condition. PMID:27403244

  8. Geochemistry of the Palitana flood basalt sequence and the Eastern Saurashtra dykes, Deccan Traps: clues to petrogenesis, dyke-flow relationships, and regional lava stratigraphy

    NASA Astrophysics Data System (ADS)

    Sheth, Hetu C.; Zellmer, Georg F.; Kshirsagar, Pooja V.; Cucciniello, Ciro

    2013-04-01

    Recent studies of large mafic dyke swarms in the Deccan Traps flood basalt province, India, indicate that some of the correlative lava flows reached several hundred kilometers in length. Here we present field, petrographic, mineral chemical, and whole-rock geochemical (including Sr-Nd isotopic) data on the Palitana lava sequence and nearby dykes in the Saurashtra region of the northwestern Deccan Traps. These rocks are moderately evolved, many with low-Ti-Nb characteristics. We infer that most dykes are notably (and systematically) less contaminated by ancient continental crust than the Palitana flows, but four dykes are equally or significantly more contaminated, with some of the most extreme Sr-Nd isotopic compositions seen in the entire Deccan Traps (initial ɛNd is as low as -18.0). A Bhimashankar-type and a Poladpur-type dyke are present several hundred kilometers from the type section of these magma types in the Western Ghats escarpment. We find no geochemical correlations between the Palitana sequence and three subsurface sequences in NE Saurashtra containing abundant picritic rocks, surface lavas previously studied from Saurashtra, or the Western Ghats sequence. Intriguingly, the Eastern Saurashtra dykes cannot have been feeders to any of these lava sequences. Feeder dykes of these sequences may be located in southwestern or central Saurashtra, or in the Dhule-Nandurbar-Dediapada areas across the Gulf of Cambay, 200-300 km east of Palitana. Our results indicate polycentric flood basalt eruptions not only on the scale of the Deccan Traps province, but also within the Saurashtra region itself.

  9. Detailled AMS analysis of recent dykes. Inferences about the flow regime and progression magnetic trends.

    NASA Astrophysics Data System (ADS)

    Pueyo Anchuela, Ó.; Gil Imaz, A.; Lago Sanjosé, M.; França, Z.; Forjaz, V. H.

    2009-04-01

    Anisotropy of Magnetic Susceptibility (AMS) has been applied to characterize the flow and emplacement conditions in tabular intrusions. The results in dykes have shown different models of relationship between the AMS ellipsoids and rock-fabric. These models include: a) imbrications during the flow observed in the margins of the intrusion (in the proximity of the dyke walls), b) magnetic lineation parallel to the flow, c) magnetic lineation normal to the flow (rolling of particles) or d) not evident relations between the flow and the magnetic axis. This complexity makes that, even when no mineralogical complexities exist, a contrast with outcrop evidences, shear indicators, orientation of grain, bubbles or vacuoles are needed. This complexity can be increased when this methodology is applied to old dykes, where not only the flow has influenced the AMS. In cases where the emplacement is syn-tectonic, or where deformational processes after the emplacement exist, the relation between flow regime and AMS can be more complex. To understand the changes and the model of emplacement in dykes, 12 recent dykes in sub-vertical position have been chosen to analyze the changes in orientation and the magnetic parameters along profiles border-center-border. The usual methodology recommends the sampling preferentially in the margin of the dykes. In this sense, the sampling has been focused in the margins but sampling also the whole extension. The average of cores for dyke is 54 (98 samples). The emplacement conditions of these dykes are related with a fracturation net parallel to the MAR in a passive manner. The dykes come from the Corvo and Flores islands, situated over North American Plate in the Western Azores (Portugal). Ten of the sampled dykes show clusters of axes and not significant variations in orientation of the magnetic ellipsoid between the sampling along the cross-sections border-center-border and the samples from both sides. Only two of the sampled dykes show

  10. Dyke Propagation Through a Partially Submerged Volcanic Edifice

    NASA Astrophysics Data System (ADS)

    Tait, S.; Taisne, B.; Limare, A.; Manga, M.; Pasquet, E.

    2014-12-01

    We have studied using analogue experiments the ascent of magma through a volcanic edifice. The edifice is simulated using a cone of gelatine and the magma is an aqueous solution. The latter is injected at the base of the cone and propagates through the edifice in hydraulic fractures that represent dykes. The buoyancy of the magma with respect to the edifice is varied by adjusting salt concentration in the aqueous solution and/or sugar concentration in the gelatine. The system is axisymmetric. After the gelatin is released from its mold, it is partially submerged in a layer of water that represents the surrounding ocean. Because the gelatin is denser than water, its weight generates an axisymmetric stress field in the edifice whose amplitude depends, for a given edifice density, on the depth of the water which represents ''sea-level''. We derive the geometry and amplitude of this stress field by using birefringence in the gelatin that results from its photoelasticity. We document the geometry of the dykes as they propagate and the elevation of eruptive fissures on the edifice as a function of the dimensionless parameters governing the system. Positive buoyancy of the magma tends to favour summit eruptions and increasing weight of the edifice (lower sea-level with respect to edifice height) tends to favour flank eruptions. We compare the experimental results with a dataset from Piton de la Fournaise, Reunion Island and draw some general conclusions about expected changes in eruptive behaviour as a volcanic island grows to greater and greater altitude above sea-level.

  11. Volcaniclastic dykes tell on fracturing, explosive eruption and lateral collapse at Stromboli volcano (Italy)

    NASA Astrophysics Data System (ADS)

    Vezzoli, Luigina; Corazzato, Claudia

    2016-05-01

    In the upper part of the Stromboli volcano, in the Le Croci and Bastimento areas, two dyke-like bodies of volcanic breccia up to two-metre thick crosscut and intrude the products of Vancori and Neostromboli volcanoes. We describe the lithofacies association of these unusual volcaniclastic dykes, interpret the setting of dyke-forming fractures and the emplacement mechanism of internal deposits, and discuss their probable relationships with the explosive eruption and major lateral collapse events that occurred at the end of the Neostromboli period. The dyke volcaniclastic deposits contain juvenile magmatic fragments (pyroclasts) suggesting a primary volcanic origin. Their petrographic characteristics are coincident with the Neostromboli products. The architecture of the infilling deposits comprises symmetrically-nested volcaniclastic units, separated by sub-vertical boundaries, which are parallel to the dyke margins. The volcanic units are composed of distinctive lithofacies. The more external facies is composed of fine and coarse ash showing sub-vertical laminations, parallel to the contact wall. The central facies comprises stratified, lithic-rich breccia and lapilli-tuff, whose stratification is sub-horizontal and convolute, discordant to the dyke margins. Only at Le Croci dyke, the final unit shows a massive tuff-breccia facies. The volcaniclastic dykes experienced a polyphasic geological evolution comprising three stages. The first phase consisted in fracturing, explosive intrusion related to magma rising and upward injection of magmatic fluids and pyroclasts. The second phase recorded the dilation of fractures and their role as pyroclastic conduits in an explosive eruption possibly coeval with the lateral collapse of the Neostromboli lava cone. Finally, in the third phase, the immediately post-eruption mass-flow remobilization of pyroclastic deposits took place on the volcano slopes.

  12. A Geochemical Investigation of the Early Cretaceous Ultrapotassic Dykes in the Raniganj Coalfields in Damodar Valley, India

    NASA Astrophysics Data System (ADS)

    Jude, T. A.

    2015-12-01

    The early Cretaceous ultrapotassic dyke rocks intruding the Permocarboniferous coal bearing Gondwana sediments of the Eastern Damodar Valley, Singhbum craton, are known for their petrographic and geochemical diversity. They remain a 'Pandora's box of petrological confusion' with a variety of exotic, and potentially diamondiferous, rocks such as lamprophyre, lamproite, orangeite and kimberlite being continuously reported from them for over one century or more. Intra-plate volcanism of this type discloses hidden information about the interior of the Earth. Samples from two dykes intruding Raniganj coalfield is studied here. The samples from Dyke1 are characterized by fine grained texture and phlogopite+apatite+K-feldspar+rutile+ankerite+dolomite+ chromite+chlorite+quartz assemblage while the samples from Dyke2 are characterized by coarse grained texture and phlogopite+ pseudomorphosed-olivine+apatite+ clinopyroxene +dolomite+ankerite+calcite+norsethite+talc+rutile+quartz+Ca-Mg-Fe-Zr silicate+K-feldspar+monazite+ perovskite assemblage. Based on the TiO2-Al2O3-FeO trends observed in phlogopites, the dykes seem to be a lamproite-orangeite transitional variety. The phlogopites observed in Dyke2 show two stages of crystallization defined by Ti-poor overgrowths on Ti-rich cores indicating that Dyke2 consolidated from a melt that fractionated from a magma which was initially emplaced at a different depth while the Dyke 1 phlogopites do not show any such sudden drop in Ti concentration in their rims indicating single stage crystallization. Ti-in-Quartz Thermometry yields temperatures between 769°C to 1115°C for Dyke1 and 779°C to 1019°C for Dyke2 which must corresponds to the emplacement and crystallization of these dykes. Trace element and isotopic ratios can be used to constrain particular mantle source characteristics of the dykes. Rb-Sr method can be used to determine the emplacement ages of these dykes.

  13. Triggered earthquakes suppressed by an evolving stress shadow from a propagating dyke

    NASA Astrophysics Data System (ADS)

    Green, Robert G.; Greenfield, Tim; White, Robert S.

    2015-08-01

    Large earthquakes can generate small changes in static stress: increases that trigger aftershock swarms, or reductions that create a region of reduced seismicity--a stress shadow. However, seismic waves from large earthquakes also cause transient dynamic stresses that may trigger seismicity. This makes it difficult to separate the relative influence of static and dynamic stress changes on aftershocks. Dyke intrusions do not generate dynamic stresses, so provide an unambiguous test of the stress shadow hypothesis. Here we use GPS and seismic data to reconstruct the intrusion of an igneous dyke that is 46 km long and 5 m wide beneath Bárðarbunga Volcano, central Iceland, in August 2014. We find that during dyke emplacement, bursts of seismicity at a distance of 5 to 15 km were first triggered and then abruptly switched off as the dyke tip propagated away from the volcano. We calculate the evolving static stress changes during dyke propagation and show that the stressing rate controls both the triggering and then suppression of earthquake rates in three separate areas adjacent to the dyke. Our results imply that static stress changes help control earthquake clustering. Similar small static stress changes may be important for triggering seismicity near geothermal areas, regions being hydrofractured and deflating oil and gas fields.

  14. Mangrove forest against dyke-break-induced tsunami on rapidly subsiding coasts

    NASA Astrophysics Data System (ADS)

    Takagi, Hiroshi; Mikami, Takahito; Fujii, Daisuke; Esteban, Miguel; Kurobe, Shota

    2016-07-01

    Thin coastal dykes typically found in developing countries may suddenly collapse due to rapid land subsidence, material ageing, sea-level rise, high wave attack, earthquakes, landslides, or a collision with vessels. Such a failure could trigger dam-break tsunami-type flooding, or "dyke-break-induced tsunami", a possibility which has so far been overlooked in the field of coastal disaster science and management. To analyse the potential consequences of one such flooding event caused by a dyke failure, a hydrodynamic model was constructed based on the authors' field surveys of a vulnerable coastal location in Jakarta, Indonesia. In a 2 m land subsidence scenario - which is expected to take place in the study area after only about 10-20 years - the model results show that the floodwaters rapidly rise to a height of nearly 3 m, resembling the flooding pattern of earthquake-induced tsunamis. The depth-velocity product criterion suggests that many of the narrow pedestrian paths behind the dyke could experience strong flows, which are far greater than the safe limits that would allow pedestrian evacuation. A couple of alternative scenarios were also considered to investigate how such flood impacts could be mitigated by creating a mangrove belt in front of the dyke as an additional safety measure. The dyke-break-induced tsunamis, which in many areas are far more likely than regular earthquake tsunamis, cannot be overlooked and thus should be considered in disaster management and urban planning along the coasts of many developing countries.

  15. Principles & Practices Board remains a valuable resource to members. Interview by Karen Hackett.

    PubMed

    McCue, J P

    1986-01-01

    In this interview, Joseph P. McCue, FHFMA, CPA, chairman of HFMA's Principles & Practices Board, discusses the history and activity of the Board since its start in 1975. According to McCue, the Board was originally formed to address the technical accounting and reporting questions unique to the healthcare industry, and nothing has changed HFMA's opinion that such a mission is still important--the necessity for a P&P Board is as acute now as it was in 1975. The interviewer is Karen Hackett, CMPA, an HFMA staff liaison with the Board. PMID:10274786

  16. The meaning and value of traditional occupational practice: a Karen woman's story of weaving in the United States.

    PubMed

    Smith, Yda J; Stephenson, Stephanie; Gibson-Satterthwaite, Michelle

    2013-01-01

    This case study sought to understand the meaning of restoring traditional weaving as an occupation among Karen women from Burma who now live in an urban city in the United States and to examine the impact of weaving on their daily lives in terms of identity, empowerment, social support, and opportunities for entrepreneurship. The story of one Karen woman, Paw Law Eh, is described. Her story exemplifies the negative consequences of restricted access to familiar and meaningful daily activities, or "occupations", the relationship between occupation and self-identity, how participation in valued occupations can enhance social networks, and the restorative effects that are possible when engagement in meaningful occupations are maintained or restored. Her story demonstrates that occupational therapists have the skills and opportunity to contribute significantly to the well-being of Karen women by supporting the restoration of the occupation of weaving. PMID:23531562

  17. "I'm Telling You ... The Language Barrier Is the Most, the Biggest Challenge": Barriers to Education among Karen Refugee Women in Australia

    ERIC Educational Resources Information Center

    Watkins, Paula G.; Razee, Husna; Richters, Juliet

    2012-01-01

    This article examines factors influencing English language education, participation and achievement among Karen refugee women in Australia. Data were drawn from ethnographic observations and interviews with 67 participants between 2009 and 2011, collected as part of a larger qualitative study exploring the well-being of Karen refugee women in…

  18. Magnetic and plagioclase fabrics in Early Cretaceous mafic dykes from Namibia

    NASA Astrophysics Data System (ADS)

    Wiegand, M.; Greiling, R. O.; Kontny, A. M.; Trumbull, R. B.

    2011-12-01

    Mafic dyke swarms are major components of the South Atlantic Large Igneous Province, which originated during the Cretaceous break up of Africa and South America. We present data from the major Henties Bay-Outjo dyke swarm (HOD) in coastal and inland NW Namibia where dykes have been emplaced into the Neoproterozoic Damara mobile belt. Most of the dykes strike at a high angle to the coast (NE-SW), but minor proportions are coast-parallel (NNW-SSE), N-S or NNE-SSW. Depending on dyke thickness (ca. 0.1 m to >100 m), the rocks are variably fine- to medium grained with chilled margins. With few exceptions the dyke compositions are tholeiitic basalt to basaltic andesite. Main minerals are plagioclase, clinopyroxene, olivine, Fe-Ti oxides, and accessory apatite and sulphides. For the magnetic study, we investigated 1140 standard cylinders from 41 dykes. The samples were studied microscopically and the following magnetic properties were determined: bulk susceptibility, anisotropy of magnetic susceptibility (P'), field dependence, hysteresis, Natural Remanent Magnetization (NRM) and Anisotropy of Anhysteretic Remanent Magnetization (AARM). Magnetic susceptibilities vary between 0.16 and 151*10-3 SI units. Microscopic studies and measurements of the temperature-dependent susceptibility identify magnetite and titanomagnetite as the dominant magnetic minerals. Hysteresis loops show that the magnetic domain states of titanomagnetite are pseudo-single or a mixture of single and multi-domain. Anisotropy is mostly low, with P' values between 1.01 and 1.15. Rare values of up to 1.33 reflect a strong magmatic flow fabric. The shapes of the AMS ellipsoids range from prolate to neutral and oblate. Two main fabric types (normal and inverse) can be recognized. We used the normal fabric type samples to interpret magmatic flow fabrics and attribute steep magnetic lineations of normal fabrics to vertical magma flow and shallow magnetic lineations to horizontal flow along the dyke planes. In

  19. Experimental and numerical investigation of the effect of basaltic dykes on transient saltwater intrusion

    NASA Astrophysics Data System (ADS)

    Abdoulhalik, Antoifi; Ahmed, Ashraf; Hamill, Gerrard

    2015-04-01

    Heterogeneity in porous media is one of the major factors that control mixing zone and saltwater wedge dynamics. Basaltic dykes are natural geological structures that can significantly affect groundwater flow and solute transport in coastal aquifers. Few recent studies have investigated the effects of heterogeneity on the freshwater-saltwater mixing zone. However, most of these studies have focused on steady-state conditions. Furthermore, as per our knowledge no one has so far completed experiments to study the impact of basaltic dykes on transient saltwater intrusion. In this study, we have performed experiments in a laboratory-scale aquifer model to study saltwater intrusion process under different heterogeneous settings; a dyke was set at different locations and several values of thickness and permeability were tested. Using a variable-head groundwater system, a head difference was imposed across the porous media and images of the transient saltwater-wedge were recorded at thirty second intervals. The experimental data sets were simulated using the MODFLOW-family variable density flow code SEAWAT. The results show that under intruding-wedge conditions, the width of the mixing zone is almost two orders of magnitude larger in the presence of the dyke than it is in the homogeneous case, while it is more than ten times larger under receding-wedge conditions. A slight increase of the toe length was observed (around nine percent) in the presence of the dyke under intruding-wedge and receding-wedge conditions. When the permeability of the dyke is further reduced, it acts as an impervious barrier that almost prevents the progression of the saltwater wedge. Thus, saltwater is accumulated along the side boundary, and then forced to drain along the bottom boundary. The results highlight the significant effects of macroscopic variations in aquifer properties (such as volcanic dykes) in the temporal evolution of mixing zone dynamics (widening and narrowing) and the

  20. Detection of Magnetically Susceptible Dyke Swarms in a Fresh Coastal Aquifer

    NASA Astrophysics Data System (ADS)

    Khalil, Mohamed H.

    2014-08-01

    Groundwater constitutes the main source of freshwater in Shalatein, on the western coast of the Red Sea, in Egypt. The fresh aquifer of Shalatein is intensively dissected by shallow and deep faults associated with the occurrence of dykes and/or dyke swarms. In this context, synthesis of electrical resistivity, ground magnetics, and borehole data was implemented to investigate the freshwater aquifer condition, locate the intrusive dykes and/or dyke swarms, and demarcate the potential freshwater zones. Nine Schlumberger VES's with maximum current electrode half-spacing (AB/2) of 682 m were conducted. The subsurface was successfully delineated by general four layers. The fresh aquifer of the Quaternary and Pre-Quaternary alluvium sediments was effectively demarcated with true resistivities ranged from 30 to 105 Ωm and thickness ranged between 20 and 60 m. A ground magnetic survey comprised 35 magnetic profiles, each 7 km in length. Magnetic data interpretation of the vertical derivatives (first and second order), downward continuation (100 m), apparent susceptibility (depth of 100 m), and wavelength filters (Butterworth high-pass of wavelengths <100 m and Band-Pass of wavelengths 30-100 m) successfully distinguished the near surface structure with five major clusters of dyke swarms, whereas filters of the upward continuation (300 m) and Butterworth low-pass (wavelengths >300 m) clearly reflected the deep-seated structure. The computed depth by the 3D Euler deconvolution for geological contacts and faults (SI = 0) ranged from 14 to 545 m, whereas for dyke and sill (SI = 1), it ranged from 10 to 1,095 m. The western part of the study area is recommended as a potential freshwater zone as it is characterized by depths >100 m to the top of the dykes, higher thickness of the fresh aquifer (45-60 m), depths to the top of the fresh aquifer ranging from 25 to 40 m, and higher resistivities reflecting better freshwater quality (70-105 Ωm).

  1. Thermal models of dyke intrusion during development of continent-ocean transition

    NASA Astrophysics Data System (ADS)

    Daniels, K. A.; Bastow, I. D.; Keir, D.; Sparks, R. S. J.; Menand, T.

    2014-01-01

    A consensus has emerged in recent years from a variety of geoscientific disciplines that extension during continental rifting is achieved only partly by plate stretching: dyke intrusion also plays an important role. Magma intrusion can accommodate extension at lower yield stresses than are required to extend thick, strong, unmodified continental lithosphere mechanically, thereby aiding the breakup process. Dyke intrusion is also expected to heat and thereby weaken the plate, but the spatial extent of heating and the effect of different rates of magmatic extension on the timescales over which heating occurs are poorly understood. To address this issue, a numerical solution to the heat-flow equation is developed here to quantify the thermal effects of dyke intrusion on the continental crust during rifting. The thermal models are benchmarked against a priori constraints on crustal structure and dyke intrusion episodes in Ethiopia. Finite difference models demonstrate that magmatic extension rate exerts a first-order control on the crustal thermal structure. Once dyke intrusion supersedes faulting and stretching as the principal extensional mechanism the crust will heat and weaken rapidly (less than 1 Ma). In the Main Ethiopian Rift (MER), the majority of present-day extension is focused on ∼20 km-wide Quaternary-Recent axial magmatic segments that are mostly seismogenic to mid-crustal depths and show P-wave seismic velocities characteristic of heavily intruded continental crust. When reviewed in light of our models, these observations require that no more than half of the MER's extension since ∼2 Ma has been achieved by dyke intrusion. Magmatic heating and weakening of the crust would have rendered it aseismic if dyke intrusion accounted for the entire 6 mm/yr extension rate. In the older, faster extending (16 mm/yr) Red Sea rift (RSR) in Afar, dyke intrusion is expected to have had a more dramatic impact on crustal rheology. Accordingly, effective elastic plate

  2. Weaving Colors into a White Landscape: Unpacking the Silences in Karen Hesse's Children's Novel "Out of the Dust"

    ERIC Educational Resources Information Center

    Simon, Lisa

    2008-01-01

    The children's novel "Out of the Dust" (Hesse, 1997) is an evocative portrayal of the drought and dust storms that devastated Midwestern farms in the 1930s. Through the voice of her 13-year-old narrator, Karen Hesse intertwines history and free verse poetry to create what many readers find to be a moving depiction of the Oklahoma Dustbowl…

  3. Medicinal plants from swidden fallows and sacred forest of the Karen and the Lawa in Thailand

    PubMed Central

    2013-01-01

    Background Many ecosystem services provided by forests are important for the livelihoods of indigenous people. Sacred forests are used for traditional practices by the ethnic minorities in northern Thailand and they protect these forests that are important for their culture and daily life. Swidden fallow fields are a dominant feature of the agricultural farming landscapes in the region. In this study we evaluate and compare the importance of swidden fallow fields and sacred forests as providers of medicinal plants among the Karen and Lawa ethnic minorities in northern Thailand. Methods We made plant inventories in swidden fallow fields of three different ages (1–2, 3–4, 5–6 years old) and in sacred forests around two villages using a replicated stratified design of vegetation plots. Subsequently we interviewed the villagers, using semi-structured questionnaires, to assess the medicinal use of the species encountered in the vegetation survey. Results We registered a total of 365 species in 244 genera and 82 families. Of these 72(19%) species in 60(24%) genera and 32(39%) families had medicinal uses. Although the sacred forest overall housed more species than the swidden fallow fields, about equal numbers of medicinal plants were derived from the forest and the fallows. This in turn means that a higher proportion (48% and 34%) of the species in the relatively species poor fallows were used for medicinal purposes than the proportion of medicinal plants from the sacred forest which accounted for 17–22%. Of the 32 medicinal plant families Euphorbiaceae and Lauraceae had most used species in the Karen and Lawa villages respectively. Conclusion Sacred forest are important for providing medicinal plant species to the Karen and Lawa communities in northern Thailand, but the swidden fallows around the villages are equally important in terms of absolute numbers of medicinal plant species, and more important if counted as proportion of the total number of species in a

  4. Board development gets straight A's: a rural hospital example. Interview by Karen Gardner.

    PubMed

    Hankinson, M P

    1992-06-01

    Copley Hospital, Morrisville, VT, is living proof that "good things come in small packages." The governing board of this 50-bed rural hospital has not let size stifle its imagination and eagerness to learn. Trustee Mary Paul Hankinson of Hyde Park, VT, has been instrumental in instituting board development activities at the hospital since she began her board tenure in 1979. Hankinson, who has taken a leave from full-time college development work to raise a family, devotes more time to Copley and her governance responsibilities than most salaried employees. As a member of the board's education and evaluation committee and the American Hospital Association's Congress of Hospital Trustees, Hankinson is alert to the educational needs and concerns of her colleagues. She recently spoke with Trustee editor Karen Gardner about the Copley board's sophisticated process for trustee orientation, self-evaluation, and continuing education. PMID:10118428

  5. Board chairman John Makel on cutting services versus diversification. Interview by Karen Gardner.

    PubMed

    Makel, J

    1990-01-01

    John Makel, chairman of the board of the Memorial Health Alliance of Mount Holly, NJ, and vice-president and regional trust office manager, First Fidelity Bank, NA-New Jersey, Moorestown, began his tenure on the board of the Memorial Hospital of Burlington County, NJ, in 1975. He has been chairman of the alliance since 1983. Makel has been involved in diversification and divestment decisions since 1979, when the alliance was formed. It now includes a 402-bed acute care hospital--the Memorial Hospital of Burlington County--a 120-bed long-term care facility, and a home health care agency that makes approximately 70,000 home care visits a year The alliance's 30-member board, under the active leadership of a 13-member executive committee, governs each of the three affiliates. Recently, Trustee managing editor Karen Gardner talked with Makel to learn how the board has approached the difficult decisions involved in cutting services versus diversification. PMID:10103487

  6. Dykes, cups, saucers and sills: Analogue experiments on magma intrusion into brittle rocks

    NASA Astrophysics Data System (ADS)

    Mathieu, L.; van Wyk de Vries, B.; Holohan, Eoghan P.; Troll, Valentin R.

    2008-07-01

    Magma is transported in the crust by blade-like intrusions such as dykes, sills, saucers, and also collects in thicker laccoliths, lopoliths and plutons. Recently, the importance and great number of shallow (< 5 km) saucer-shaped intrusions has been recognized. Lopoliths and cup-shaped intrusions have also been reported in many geological contexts. Our field observations indicate that many intrusions, especially those emplaced into breccias or fractured rocks, have bulging, lobate margins and have shear faults at their bulbous terminations. Such features suggest that magma can propagate along a self-induced shear fault rather than a hydraulic tension-fracture. To investigate this we use analogue models to explore intrusion propagation in a brittle country rock. The models consist of the injection of analogue magma (honey or Golden syrup) in a granular material (sand or sieved ignimbrite) that is a good analogue for brittle or brecciated rocks. These models have the advantage (over other models that use gelatin) to well represent the properties of brittle materials by allowing both shear-faults and tension fractures to be produced at suitable stresses. In our experiments we mainly obtain vertical dykes and inverted-cone like structures that we call cup-shaped intrusions. Dykes bifurcate into cup-shaped intrusions at depths depending on their viscosity. All cup-shaped intrusions uplift a central block. By injecting against a vertical glass plate we obtain detailed observations of the intrusion propagation style. We observe that dykes commonly split and produce cup-shaped intrusions near the surface and that shear zone-related intrusions develop at the dyke tip. We conclude that many dykes propagate as a viscous indenter resulting from shear failure of host rock rather than tensional hydraulic fracturing of host rocks. The shear propagation model provides an explanation for the shape and formation of cup-shaped intrusions, saucer-sills and lopoliths.

  7. The dykes and structural setting of the volcanic front in the Lesser Antilles island arc

    NASA Astrophysics Data System (ADS)

    Wadge, G.

    1986-12-01

    The orientations of dykes from many of the islands of the Lesser Antilles island arc have been mapped. Most of these dykes can be interpreted in terms of local or regional swarms derived from specific volcanoes of known age, with distinct preferred orientations. Dykes are known from all Cenozoic epochs except the Palaeocene, but are most common in Pliocene, Miocene and Oligocene rocks. A majority of the sampled dykes are basaltic, intrude volcaniclastic host rocks and show a preference for widths of 1 1.25 m. Locally, dyke swarms dilate their hosts by up to 9% over hundreds of metres and up to 2% over distances of kilometres. The azimuths of dykes of all ages show a general NE-SW preferred orientation with a second NW-SE mode particularly in the Miocene rocks of Martinique. The regional setting for these minor intrusions is a volcanic front above a subduction zone composed of three segments: Saba-Montserrat, Guadeloupe-Martinique, St. Lucia-Grenada. The spacing of volcanic centres along this front is interpreted in terms of rising plumes of basaltic magma spaced about 30 km apart. This magma is normally intercepted at crustal depths by dioritic plutons and andesitic/dacitic magma generated there. Plumes which intersect transverse fracture systems or which migrate along the front can avoid these crustal traps. Throughout its history the volcanic front as a whole has migrated, episodically, towards the backarc at an average velocity of about 1 km/Ma. The local direction of plate convergence is negatively correlated with the local preferred orientation of dykes. The dominant NE-SW azimuth mode corresponds closely to the direction of faulting in the sedimentary cover of the backarc and the inferred tectonic fabric of the oceanic crust on which the arc is founded. A generalised model of the regional stress field that controls dyke intrusion outside of the immediate vicinity of central volcanic vents is proposed, in which the maximum horizontal stress parallels the

  8. Late Cretaceous -Early Tertiary dyke swarm of North Greenland it's age, origins and tectonic significance

    NASA Astrophysics Data System (ADS)

    Manby, Geoffrey

    2014-05-01

    North Greenland is characterized by N-S, NW-SE and E-W trending swarms of mafic dykes which pre- and post date Kap Washington suite of bimodal lavas, ash flows and tuffs. Both rock groups are over-thrust by north vergent thrust sheets of Early Palaeozoic age rocks which record low grade Ellesmerian (Carboniferous) metamorphism and deformation. Laser ablation Ar/Ar ages of 58Ma and 62Ma obtained from thrust fault generated mylonites suggest that magmatism must have effectively ceased by then as no undeformed dykes have been found to cross the thrust planes. High resolution PMAP aeromagnetic surveys for 1989 and 1997-98 show that linear magnetic anomalies parallel to the dense N-S trending dyke swarm of Nansen Land can be traced out onto the Lincoln Sea platform suggesting the dykes are part of the predominantly offshore failed rift magmatic domain which lies central to the southern ends of Alpha ridge, the Lomonosov Ridge, the Markarov Basin, the Amundsen Basin and the Morris-Jessup Plateau. In addition the dykes to the SW of the Mascart Inlet appear to extend undisturbed by faulting 150km onto the Lincoln Sea platform north of Ellesmere Island. The curved ca EW deep negative anomaly which truncates the dyke swarm offshore to the north of the Kap Canon Fault zone together with a similar anomaly along the Harder fjord Fault Zone and its western continuation to the Kap Ramsey Fault appear to constitute the limits of Eurekan thrust belt of North Greenland. Stress tensor analyses of all Eurekan fault plane populations show a consistent N-S to NNW-SSE pure compression pattern orthogonal to the main thrust faults and near parallel to the main dyke trend. Rb/Sr, and Ar/Ar ages obtained from biotite separates, with U/Th ages from apatite-feldspar pairs suggest the dykes range in age from ca 103Ma to 69Ma. The peralkaline affinity of the dyke swarm is similar to that of many other rift generated basalts. Nd, Sr and a small number of Pb isotope ratios have been determined for

  9. Dyke-path formation in relation to the eruptions of Eyjafjallajökull 2010 and Bardarbunga-Holuhraun 2014

    NASA Astrophysics Data System (ADS)

    Gudmundsson, Agust

    2015-04-01

    Dykes are extension fractures and form when the magmatic overpressure is high enough to rupture (break) the host rock. Their formation is entirely analogous to that of many joints and human-made hydraulic fractures, such as are used to increase permeability in reservoirs. When generating their paths, dykes use existing weaknesses (e.g., cooling joints) in the host rock. The maximum depth of large tension fractures below the surface of a rift zone, however, is mostly less than a few hundred metres. If the fractures extend to greater depths, they must change into closed normal faults which are generally not used as magma paths. There are thus no large tension fractures or wide-open faults at great depths ready to be filled with magma to form a dyke. While magma flow in dykes, as in other fluid-driven fractures, is at any point in various directions dyke segmentation may indicate the overall large-scale flow direction. Thus, dykes composed of large-spaced disconnected segments in lateral sections are primarily formed in vertical magma flow at segmentation depth whereas those composed of large-spaced disconnected segments in vertical sections are primarily formed in lateral magma flow. The far-field displacement and stress fields of segmented dykes are similar to those generated by single, continuous dykes of similar dimensions, particularly when the distances between the nearby tips of the segments become small in comparison with segment lengths. Most dykes become arrested and never supply magma to eruptions. Feeder-dykes normally reach the surface only along parts of their lengths (strike-dimensions). The volumetric flow or effusion rate of magma through a feeder-dyke or volcanic fissure depends on the aperture (opening) of the dyke or fissure in the 3rd power. All these theoretical and observational results are here applied to the dyke emplacements associated with the eruptions of Eyjafjallajökull 2010 and Bardarbunga-Holuhraun 2014. The results make it possible to

  10. Formation conditions of leucogranite dykes and aplite-pegmatite dykes in the eastern Mt. Capanne plutonic complex (Elba, Italy): fluid inclusion studies in quartz, tourmaline, andalusite and plagioclase

    NASA Astrophysics Data System (ADS)

    Bakker, Ronald J.; Schilli, Sebastian E.

    2016-02-01

    Leucogranite and aplite-pegmatite dykes are associated with the Mt. Capanne pluton (Elba) and partly occur in the thermally metamorphosed host rock (serpentinites). Crystallization conditions of these dykes in the late magmatic-hydrothermal stage are estimated from fluid inclusion studies and mineralogical characterisation, obtained from detailed microthermometry, Raman spectroscopy, and electron microprobe analyses. Fluid inclusion assemblages are analysed in andalusite, quartz, and plagioclase from the leucogranite dykes, and in tourmaline and quartz from the aplite-pegmatite dykes. The fluid inclusion assemblages record multiple pulses of low salinity H2O-rich magmatic and reduced metamorphic fluid stages. Magmatic fluids are characterized by the presence of minor amounts of CO2 and H3BO3, whereas the metamorphic fluids contain CH4 and H2. The highly reduced conditions are also inferred from the presence of native arsenic in some fluid inclusions. Several fluid inclusion assemblages reveal fluid compositions that must have resulted from mixing of both fluid sources. In leucogranite dykes, magmatic andalusite contains a low-density magmatic CO2-rich gas mixture with minor amounts of CH4 and H2. Accidentally trapped crystals (mica) and step-daughters (quartz and diaspore) are detected in some inclusions in andalusite. The first generation of inclusions in quartz that crystallized after andalusite contains a highly reduced H2O-H2 mixture and micas. The second type of inclusions in quartz from the leucogranite is similar to the primary inclusion assemblage in tourmaline from the aplite-pegmatite, and contains up to 4.2 mass% H3BO3, present as a sassolite daughter crystal or dissolved ions, in addition to a CO2-CH4 gas mixture, with traces of H2, N2, H2S, and C2H6. H2O is the main component of all these fluids ( x = 0.91 to 0.96) with maximally 7 mass% NaCl. Some accidentally trapped arsenolite and native arsenic are also detected. These fluids were trapped in the

  11. Dyke-Davidoff-Masson syndrome: imaging features with illustration of two cases

    PubMed Central

    Rani, Jyotsna Y.

    2015-01-01

    Dyke-Davidoff-Masson syndrome is a rare entity characterized by hemi cerebral atrophy/hypoplasia secondary to brain insult in fetal or early childhood period along with ipsilateral compensatory osseous hypertrophy and contralateral hemiparesis. We present two cases of this uncommon condition and discuss its imaging features, differential diagnosis, treatment options and prognosis. PMID:26029650

  12. The 2004 dyke-fault interaction at Dallol, northern Afar (Ethiopia)

    NASA Astrophysics Data System (ADS)

    Nobile, A.; Pagli, C.; Keir, D.; Wright, T.; Ruch, J.; Acocella, V.

    2012-04-01

    The 2005 Dabbahu intrusive event in Afar highlighted the importance of magma in controlling rifting along divergent plate boundaries. Here we show that a further intrusive event occurred in late 2004 at Dallol, along the axis of the Red Sea Rift in northern Afar. Dallol consists of an hydrothermal area lacking significant volcanic activity at the northern end of the Erta Ale volcanic segment. We use InSAR and seismicity data to constrain the geometric and kinematic features of the intrusion, as well as its possible effects. The dyke intruded a 6 km portion of the rift, from Dallol volcano, which subsided, to the south. The intrusion was accompanied by a seismic sequence, including a Mw 5.5 earthquake on 22 October. The larger events were registered by several seismic stations worldwide and located by the International Seismological Center (ISC). InSAR data from Envisat allow us to measure the surface deformation associated with these events. An inversion for a simple elastic model suggests that a ~3m wide and ~46km3 volume dyke was accompanied by fault slip. Seismicity observations suggest that the Mw 5.5 earthquake was triggered by the dyke intrusion. These results at Dallol provide the northernmost evidence of dyke-induced extension in Afar, occurring shortly before the 2005 event at Dabbahu.

  13. Geochemistry and petrogenesis of proterozoic mafic dykes in north Kerala, southwestern Indian Shield - Preliminary results

    NASA Technical Reports Server (NTRS)

    Radhakrishna, T.; Gopakumar, K.; Murali, A. V.; Mitchell, J. G.

    1991-01-01

    Mafic dyke intrusions occur in three distinct orientations ( NNW-SSE and NW-SE and NE-SW) in north Kerala regions, the southwestern part of the Indian Shield. Dating of two NNW-SSE trending dykes by K-Ar method has yielded Middle Proterozoic ages (ca. 1660 Ma and ca. 1420 Ma respectively). Our initial geochemical results on these dyke rocks (0.65-0.15 wt pct K2O, 0.37-0.38 wt pct P2O5, 3.30-1.00 wt pct TiO2, 11-1 p.p.m. Rb, 250-90 p.p.m. Sr, 230-40 p.p.m. Ba, 160-40 p.p.m. Zr, and 30-10 x chondrite rare earth elemental abundances) indicate a transitional character between abyssal and plateau tholeiites. Petrogenetic modelling suggests that the dyke compositions have been derived by different degrees of partial melting of a heterogenous source mantle. The mantle sources with accessory amphibole and/or garnet, variably enriched in LREE and LIL elements, are compatible with the observed geochemical data.

  14. Dyke Intrusion and Arrest in Harrat Lunayyir, western Saudi Arabia, in April-July 2009

    NASA Astrophysics Data System (ADS)

    Jónsson, Sigurjón; Pallister, John; McCausland, Wendy; El-Hadidy, Salah

    2010-05-01

    Dyke intrusion in Harrat Lunayyir (also known as Harrat Al-Shaqah), one of the volcanic provinces in Saudi Arabia, caused numerous small to moderate-sized earthquakes and extensive surface faulting in April-July 2009. The most intensive earthquake activity took place on 17-20 May when six magnitude 4.6-5.7 earthquakes occurred, resulting in some structural damage and prompting the Saudi civil protection authorities to evacuate more than 30000 people from the area. While the earthquake activity significantly decreased after 20 May, it continued throughout June and July with a few earthquakes as large as magnitude ~4, before quieting down in August. Much of what we have learned about the activity comes from interferometric satellite radar (InSAR) observations and from analysis of the seismic data collected by a broadband seismic network that was installed soon after the earthquake swarm started in April. The InSAR data show that large-scale (40 km × 40 km) east-west extension of over 1 m took place as well as broad uplift amounting to over 40 cm. The center of the uplifted area was transected by northwest-trending graben subsidence of over 50 cm, bounded by a single fault to the southwest showing up to ~1 m of faulting and by multiple smaller faults and cracks to the northeast. The observed deformation is well explained with a near-vertical dyke intrusion and graben-bounding normal faulting. The strike of the model dyke is NNW-SSE, parallel to the Red Sea rift, and its volume is about 0.13 km3. The modeling suggests that the shallowest part of the dyke reached within only 2 km of the surface, right below where the graben is the narrowest and under an area with a number of cinder cones from previous volcanic events. The main graben-bounding surface fault, to the southwest of the dyke, grew from ~3 km to ~8 km with the magnitude 5.7 earthquake on 19 May. Soon after this event the overall earthquake activity dramatically declined. The faulting appears to have

  15. Geometry and emplacement of the Late Cretaceous mafic dyke swarms on the islands in Zhejiang Province, Southeast China: Insights from high-resolution satellite images

    NASA Astrophysics Data System (ADS)

    Chen, Ning-hua; Dong, Jin-jin; Chen, Jian-yu; Dong, Chuan-wan; Shen, Zhong-yue

    2014-01-01

    The geology of Zhejiang coastal area in Southeast China is characterized by numerous Late Mesozoic intrusive rocks and widespread mafic dyke swarms, which indicate continental lithospheric extensional events during the Jurassic and Cretaceous. This work is focused on using multisource high-resolution remote sensing images (Worldview2, Geoeye1 and Quickbird2) to identify the geometry, morphology and location of previously undocumented and poorly understood dyke swarms exposed on the islands in Zhejiang Province. The geometry of each dyke is described by its strike, length and thickness. The spatial distribution of the dyke density and crustal dilation are obtained based on the statistics of 774 extracted mafic dykes. Field surveys are performed in some islands in order to analyze the detailed geometric features and assess the interpretative accuracy. The spectral measurement and analysis of mafic dykes are performed as well for remote sensing imagery processing and lithological interpretation. The results show that the frequency distributions of the length and thickness of dykes follow power law curves. The maximum and mean dyke thicknesses are 11.2 m and 1.43 m, respectively. The crustal dilation of the islands ranges from 0.09% to 7.4%. From the north to the south islands, the dilation decreases gradually. The dyke frequency and density have the same distribution as the dilation. According to 40Ar-39Ar age (Zhongshanjie archipelago) and U-Pb zircon age (Sijiao Island) of the mafic dyke, the dyke swarms on the eastern Zhejiang islands emplaced at around 87-97 Ma. The cross-cutting relationships of dykes and host rocks show that the mafic dyke swarms have close spatial correlations with granite. The dykes stretch in various directions whereas the NE-trending dykes dominate. Our research reveals four intrusive events that imply the crustal extension and intermittent variation of the regional stress field in the coastal area of southeastern China in the Late

  16. Geophysical characteristics of Aswa shear, Nagasongola discontinuity and ring dyke complex in Uganda

    NASA Astrophysics Data System (ADS)

    Ruotoistenmäki, Tapio

    2014-05-01

    During the years 2008-2012, the geology of most of Uganda was studied within the framework of the Sustainable Management of Mineral Resources Project (SMMRP). During the project, comprehensive airborne magnetic and radiometric surveys were flown over the entire country and geological, petrophysical, geochemical sampling, geological field studies and detailed geophysical field profiles were undertaken in selected sub-areas. This report concentrates on the geophysical properties of three major geophysical structures in the area considered during the project: the Pan-African (0.6-0.7 Ga) Aswa shear zone and Nagasongola discontinuity (suture), and the 1.36 Ga Uganda-Tanzania semi-circular ‘ring dyke' complex. The geophysical profiles across the Aswa shear indicate that the fault zone dips steeply, at about 60° to NE. The structure represents a magnetic, gravimetric (density), radiometric and topographic discontinuity, all diminishing from SW to NE across the zone. The zone is also characterized by complex radiometric anomalies. A schematic reconstruction of the evolution of the Aswa shear zone on the magnetic map suggests a nearly 60 km sinistral horizontal component of displacement along the zone. The Nakasongola zone is another distinct magnetic, gravimetric and radiometric discontinuity, interpreted to represent a collision (suture) zone, where the northern, low-magnetic block has been thrust over the southern, denser and more magnetic block. Modeling of gravity and magnetic data are consistent with a geometry in which the southern, magnetic and high-density block dips gently to great depth beneath the northern block. Bedrock exposures in both the Aswa shear zone and Nagasongola zone areas indicate a very protracted and complex history of tectonic processes commencing in the Archaean-Paleoproterozoic era and culminating in Pan-African orogenies. Both, the Aswa shear zone and Nagasongola discontinuity are cut by continuous younger dykes that show no signs of

  17. Paleomagnetism of the Grenville diabase dyke swarm and implications for the mid Vendian paleolatitude of Laurentia

    NASA Astrophysics Data System (ADS)

    Buchan, K. L.; Ernst, R. E.; Kumarapeli, P. S.

    2004-05-01

    The Vendian-early Cambrian drift of Laurentia is important for theories of `Snowball Earth' and the continental breakup that formed the Iapetus Ocean. However, estimates of Laurentia's paleolatitude in this period differ widely. Some authors have proposed that Laurentia remained in low latitude throughout this period, whereas others have supported rapid drift of the continent from low to high and back to low latitude. To assist in evaluating these models, a paleomagnetic study was conducted on the mid Vendian Grenville dyke swarm of southeastern Laurentia. This 700 km long swarm was emplaced along the Ottawa graben, an aulacogen associated with rifting that preceded the opening of the Iapetus Ocean. The swarm was the subject of an early paleomagnetic study by Murthy (1971). More recently, U-Pb baddeleyite and zircon ages of ca. 590 Ma have been described for three Grenville dykes (Kamo et al. 1995). At one of these sites, on the `Mattawa' dyke, a positive paleomagnetic baked contact test was also reported (Hyodo and Dunlop 1993). In that detailed test thermoremanent overprinting in the zone of hybrid magnetization was shown to match that expected from heat conduction for a cooling dyke. Nevertheless, Hyodo and Dunlop suggested that the steep down remanence in the dyke, although primary, was likely acquired during a geomagnetic excursion because it did not appear to fit the then-available polar wander path. In our study, paleomagnetic sampling was carried out at 36 sites, including all three dated locations. A detailed analysis has been completed for the dated sites and preliminary analysis for the remaining sites. A stable steep down remanence was obtained for all samples in the Mattawa dyke, and in most samples from a second dated site. The third dated site is less stably magnetized and has not yielded a usable remanence direction. Ten additional sites yield stable steep down or occasionally steep up remanences. The presence of a steep remanence in two dated dykes

  18. Triggering of microearthquakes in Iceland by volatiles released from a dyke intrusion

    NASA Astrophysics Data System (ADS)

    Martens, Hilary R.; White, Robert S.

    2013-09-01

    We suggest that carbon dioxide exsolved from a mid-crustal basaltic dyke intrusion in Iceland migrated upwards and triggered shallow seismicity by allowing failure on pre-existing fractures under the relatively low elastic stresses (100-200 kPa; 1-2 bar) generated by the dyke inflation. Intense swarms of microseismicity accompanied magmatic intrusion into a dyke at depths of 13-19 km in the crust of Iceland's Northern Volcanic Rift Zone during 2007-2008. Contemporaneously, a series of small normal earthquakes, probably triggered by elastic stresses imposed by the dyke intrusion, occurred in the uppermost 4 km of crust: fault plane solutions from these are consistent with failure along the extensional fabric and surface fissure directions mapped in the area, suggesting that the faults failed along existing rift zone fabric even though the mid-crustal dyke is highly oblique to it. Several months after the melt froze in the mid-crust and seismicity associated with the intrusion had ceased, an upsurge in shallow microseismicity began in the updip projection of the dyke near the brittle-ductile transition at 6-7 km depth below sea level. This seismicity is caused by failure on right-lateral strike-slip faults, with fault planes orientated 23 ± 3°, which are identical with the 24 ± 2° orientation in this area of surface fractures and fissures caused by plate spreading and extension of the volcanic rift zone. However, these earthquakes have T-axes approximately aligned with the opening direction of the dyke, and the right-lateral sense of failure is opposite that of regional strike-slip faults. We suggest that the fractures occurred along pre-existing weaknesses generated by the pervasive fabric of the rift zone, but that the dyke opening in the mid-crust beneath it caused right-lateral failure. The seismicity commenced after a temporal delay of several months and has persisted for over 3 yr. We propose that fluids exsolved from the magma in the dyke, primarily carbon

  19. 40Ar/39Ar geochronology and geochemistry of the Central Saurashtra mafic dyke swarm: insights into magmatic evolution, magma transport, and dyke-flow relationships in the northwestern Deccan Traps

    NASA Astrophysics Data System (ADS)

    Cucciniello, Ciro; Demonterova, Elena I.; Sheth, Hetu; Pande, Kanchan; Vijayan, Anjali

    2015-05-01

    The Central Saurashtra mafic dyke swarm in the northwestern Deccan Traps contains a few picrites, several subalkalic basalts and basaltic andesites, and an andesite. We have obtained precise 40Ar/39Ar ages of 65.6 ± 0.2 Ma, 66.6 ± 0.3, and 62.4 ± 0.3 Ma (2σ errors) for three of the dykes, indicating the emplacement of the swarm over several million years. Mineral chemical and whole-rock major and trace element and Sr-Nd isotopic data show that fractional crystallization and crystal accumulation were important processes. Except for two dykes (with ɛNd t values of -8.2 and -12.3), the magmas were only moderately contaminated by continental crust. The late-emplaced (62.4 Ma) basalt dyke has compositional characteristics (low La/Sm and Th/Nb, high ɛNd t of +4.3) suggesting little or no crustal contamination. Most dykes are low-Ti and a few high-Ti, and these contrasting Ti types cannot be produced by fractional crystallization processes but require distinct parental magmas. Some dykes are compositionally homogeneous over tens of kilometers, whereas others are heterogeneous, partly because they were formed by multiple magma injections. The combined field and geochemical data establish the Sardhar dyke as ≥62 km long and the longest in Saurashtra, but this and the other Central Saurasthra dykes cannot have fed any of the hitherto studied lava-flow sequences in Saurashtra, given their very distinct Sr-Nd isotopic compositions. As observed previously, high-Ti lavas and dykes only outcrop east-northeast of a line joining Rajkot and Palitana, probably because of underlying enriched mantle at ~65 Ma.

  20. Evidences for multiple remagnetization of Proterozoic dykes from Iguerda inlier (Anti-Atlas Belt, Southern Morocco)

    NASA Astrophysics Data System (ADS)

    Neres, Marta; Silva, Pedro F.; Ikene, Moha; Martins, Sofia; Hafid, Ahmid; Mata, João; Almeida, Francisco; Youbi, Nasrrddine; Boumehdi, Ahmed

    2016-04-01

    Paleomagnetic data able to constrain the paleoposition of the West African Craton (WAC) during Paleo-Mesoproterozoic are absent, mainly due to gaps on the sedimentary record and intense remagnetizations. Dykes that intrude several Proterozoic inliers of WAC in the Anti-Atlas Belt (southern Morocco) have recently been subjected to geochronological studies, which revealed ages between Paleoproterozoic and early Neoproterozoic. Therefore, these dykes represent a window of opportunity for paleomagnetic studies aiming to infer about the paleoposition of WAC during Proterozoic. On this scope we conducted a paleomagnetic study on seven Proterozoic dykes of the Iguerda inlier. We determined the paleomagnetic directions and evaluated their meaning by rock magnetic and mineral analyses, complemented by petrographic observations. Results revealed that these rocks record the presence of a complex history of remagnetization events, mostly assigned to several Phanerozoic thermal/chemical events. In particular, we found components assigned to the late stages of Pan African orogeny (s.l.), to the Late Carboniferous Variscan orogeny, and to more recent events. The recognized remagnetization processes are related to widespread metamorphic events under greenschist facies followed by low-temperature oxidation, both responsible for the formation of new magnetic phases (magnetite and hematite). The primary (magmatic) thermo-remanent magnetization of the dykes was obliterated during these events through multiple thermal and chemical remagnetizations. For only one dyke the presence of primary magnetization is possible to infer, though not to confirm, and would place WAC at an equatorial position around 1750 Ma. The authors wish to acknowledge FCT (Portugal) - CNRST (Morocco) bilateral agreement for its major contribution without which this work wouldn't be possible. Publication supported by project FCT UID/GEO/50019/2013 - Instituto Dom Luiz.

  1. Magma flow pattern in dykes of the Azores revealed by anisotropy of magnetic susceptibility

    NASA Astrophysics Data System (ADS)

    Moreira, M. A.; Geoffroy, L.; Pozzi, J. P.

    2015-02-01

    The localization of magma melting areas at the lithosphere bottom in extensional volcanic domains is poorly understood. Large polygenetic volcanoes of long duration and their associated magma chambers suggest that melting at depth may be focused at specific points within the mantle. To validate the hypothesis that the magma feeding a mafic crust, comes from permanent localized crustal reservoirs, it is necessary to map the fossilized magma flow within the crustal planar intrusions. Using the AMS, we obtain magmatic flow vectors from 34 alkaline basaltic dykes from São Jorge, São Miguel and Santa Maria islands in the Azores Archipelago, a hot-spot related triple junction. The dykes contain titanomagnetite showing a wide spectrum of solid solution ranging from Ti-rich to Ti-poor compositions with vestiges of maghemitization. Most of the dykes exhibit a normal magnetic fabric. The orientation of the magnetic lineation k1 axis is more variable than that of the k3 axis, which is generally well grouped. The dykes of São Jorge and São Miguel show a predominance of subhorizontal magmatic flows. In Santa Maria the deduced flow pattern is less systematic changing from subhorizontal in the southern part of the island to oblique in north. These results suggest that the ascent of magma beneath the islands of Azores is predominantly over localized melting sources and then collected within shallow magma chambers. According to this concept, dykes in the upper levels of the crust propagate laterally away from these magma chambers thus feeding the lava flows observed at the surface.

  2. "Here nobody holds your heart": metaphoric and embodied emotions of birth and displacement among Karen women in Australia.

    PubMed

    Niner, Sara; Kokanovic, Renata; Cuthbert, Denise; Cho, Violet

    2014-09-01

    Our objective was to explore the ways in which displaced Karen mothers expressed emotions in narrative accounts of motherhood and displacement. We contextualized and analyzed interview data from an ethnographic study of birth and emotions among 15 displaced Karen mothers in Australia. We found that women shared a common symbolic language to describe emotions centered on the heart, which was also associated with heart "problems." This, along with hypertension, collapsing, or a feeling of surrender were associated responses to extremely adverse events experienced as displaced peoples. A metaphoric schema of emotional terms centered on the heart was connected to embodied expressions of emotion related to illness of the heart. This and other embodied responses were reactions to overwhelming difficulties and fear women endured due to their exposure to political conflict and global inequity. PMID:24599643

  3. Structural and palaeomagnetic Analysis of the Koolau Dyke Swarm Exposed in the Kapa'a Quarry, Oahu: Implications for the Structural Evolution of Kilauea - Type Volcanic Rift Zones.

    NASA Astrophysics Data System (ADS)

    Day, S. J.; Herrero-Bervera, E.; Knight, M. D.

    2003-12-01

    The Koolau dyke swarms, exposed within the Kailua embayment on the northeastern side of Oahu, have been interpreted as feeders to rift zones in the Koolau volcano, analagous to the rift zones of Kilauea volcano (Walker, 1987), that developed prior to the giant Nuuanu lateral collapse at about 2.0 Ma. Systematic determination of cross-cutting relationships between Koolau dykes has proved difficult because of dense vegetation and rapid weathering in the humid tropical climate of windward Oahu. For this study we have concentrated on exposures of the dykes in the large (450 m wide and 200m deep) Kapa'a quarry, about 3 km NE of the near vertical Nuuanu Pali escarpment. Kapa'a quarry was chosen for this study because it has large, freshly exposed sections nearly perpendicular to the dyke swarm trend in hydrothermally altered but largely unweathered rocks. The hydrothermal alteration indicates that the dykes exposed in the quarry were emplaced well below a high water table resulting from trapping of water between dykes: this high water table may have played a part in the eventual collapse. The excellent exposure at Kapa'a allows systematic, accurate determination of structural data and cross-cutting relationships for every dyke in the measured sections. These data were collected for 171 dykes, of which 10 dykes have so far been sampled for palaeomagnetic analysis (i.e remanence and petrofabrics). Most dykes at Kapa'a dip steeply, from around 70 degrees SW (away from the unstable flank of the volcano) through vertical to 50 degrees NE (towards the unstable flank). NE dipping dykes are more abundant overall. Groups of SW - dipping dykes alternate with groups of subvertical to NE - dipping dykes, suggesting a quasi-periodic alternation of the stress regime within the Koolau volcano. Dyke dilations were typically subhorizontal. A final group of dykes, cross-cutting all the others, dip from 50 degrees NE to as little as 35 degrees NE, and dilated in a steeply SW - plunging

  4. ArcGIS studies and field relationships of Paleoproterozoic mafic dyke swarms from the south of Devarakonda area, Eastern Dharwar Craton, southern India: Implications for their relative ages

    NASA Astrophysics Data System (ADS)

    Samal, Amiya K.; Srivastava, Rajesh K.; Sinha, Lokesh K.

    2015-07-01

    Google Earth Image and cross-cutting field relationships of distinct Paleoproterozoic mafic dykes from south of Devarakonda area in the Eastern Dharwar Craton has been studied to establish relative emplacement ages. The Devarakonda, covering an area of ˜700 km2, shows spectacular cross-cutting field relationships between different generations of mafic dykes, and is therefore selected for the present study. Although some recent radiometric age data are available for distinct Paleoproterozoic mafic dykes from the Eastern Dharwar Craton, there is no analogous age data available for the study area. Therefore, relative age relationships of distinct mafic dykes have been established for the study area using cross-cutting field relationships and GIS techniques, which shows slightly different picture than other parts of the Eastern Dharwar Craton. It is suggested that NE-SW trending mafic dykes are youngest in age (probably belong to ˜1.89 Ga dyke swarm), whereas NNW-SSE trending mafic dykes have oldest emplacement age. Further, the NNW-SSE mafic dykes are older to the other two identified mafic dyke swarms, i.e., WNW-ESE (˜2.18 Ga) and N-S trending (˜2.21 Ga) mafic dyke swarms, as dykes of these two swarms cross-cut a NNW-SSE dyke. It provides an evidence for existence of a new set of mafic dykes that is older to the ˜2.21 Ga and probably younger to the ˜2.37 Ga swarm. Present study also supports existence of two mafic dyke swarms having similar trend (ENE-WSW to NE-SW) but emplaced in two different ages (one is ˜2.37 Ga and other ˜1.89 Ga).

  5. Building for ambulatory care: Children's Hospital grows with the times. Interview by Karen Gardner.

    PubMed

    Colley, R

    1992-02-01

    The Children's Hospital of Philadelphia, a 294-bed regional referral center, was the first dedicated children's hospital established in the United States in 1855. Although 39 percent of its beds are designated for intensive care, in 1985 the hospital's board recognized the necessity of expanding its ambulatory care capacity. Much of the credit for implementation of this vision goes to Roger Colley--a trustee recruited in 1983 for his business acumen. At the time he joined the board, Colley had been president of Betz Laboratories Inc., Philadelphia. In 1988, Colley started his own company--Envirogen--a company dedicated to finding new, innovative and lower-cost technologies for treating toxic and hazardous industrial waste. He is president and CEO of Envirogen, Lawrenceville, NJ. Colley was one of the original members of the hospital's long-range planning committee and served as chairman of the board's building and grounds committee during construction (from 1987-89) of the six-story Richard D. Wood Ambulatory Care Center. He recently spoke with Trustee editor Karen Gardner about the process of building this new facility, which opened in September 1989. PMID:10116268

  6. New Paleomagnetic Results from Late Cretaceous Volcanics and Dykes, SouthWest India

    NASA Astrophysics Data System (ADS)

    Perrin, M.; Joseph, M.; Monie, P.

    2015-12-01

    Late Cretaceous magmatism is widely distributed along the south west coast of India, mainly in the form of dyke intrusions. Most prominent dykes were emplaced around 65 Ma and are distributed in central Kerala, north Kerala and Goa. The strike trend of these dykes is NW-SE in central Kerala, whereas two orthogonal directions with NW-SE and NE-SW trends are found in north Kerala. In Goa region, they are mostly perpendicular to the coast. 25 sites (232 samples) have been collected in Kerala and Goa areas. A subordinate magmatism, around 90 Ma in age, is also traced in Agali area and St Mary Archipelago off the Malpe coast. Nine dykes (79 samples) with NW-SE trend were collected, and 9 flows (63 samples) from 8 different islands of the St Mary Archipelago. Finally, following some field evidences, the Ezhimala igneous complex, south of St Mary Islands, that occurs as a linear ridge with a NNW-SSE trend and consists mainly of granite, granophyre and gabbro, cut by dolerites, was also sampled (9 sites, 58 samples) despite its inferred Precambrian age (Rb-Sr determinations at 678 Ma). Finally, in order to constrain the duration of the Deccan volcanism, some of the younger and of the older flows (55 sites, 309 samples) were also collected. Most of the doleritic dykes are fine to medium grained with typical mineral assemblages of plagioclase, augite, olivine, and Fe-Ti oxides. All the mafic dykes of Kerala plot within the sub-alkalic field but three groups can be distinguished chemically. Fe-Ti oxides are found either as early inclusions within pyroxene or as interstitial and may constitute the late crystallization phases. Selected specimens from each site were subjected to low and high temperature susceptibility measurements to define the magnetic carriers and the thermal stability of the samples. They have indicated titanomagnetite as the main carrier of magnetization. Palaeomagnetic measurements were carried out by detailed step-wise alternating field and thermal

  7. Ford Van Dyke: Compressed Air Management Program Leads to Improvements that Reduce Energy Consumption at an Automotive Transmission Plant

    SciTech Connect

    2010-06-25

    Staff at the Ford Van Dyke Transmission Plant in Sterling Heights, Michigan, have increased the efficiency of the plant’s compressed air system to enhance its performance while saving energy and improving production.

  8. Radial patterns of bitumen dykes around Quaternary volcanoes, provinces of northern Neuquén and southernmost Mendoza, Argentina

    NASA Astrophysics Data System (ADS)

    Cobbold, Peter R.; Ruffet, Gilles; Leith, Leslie; Loseth, Helge; Rodrigues, Nuno; Leanza, Hector A.; Zanella, Alain

    2014-12-01

    Where the Neuquén Basin of Argentina abuts the Andes, hundreds of veins of solid hydrocarbon (bitumen) are visible at the surface. Many of these veins became mines, especially in the last century. By consensus, the bitumen has resulted from maturation of organic-rich shales, especially the Vaca Muerta Fm of Late Jurassic age, but also the Agrio Fm of Early Cretaceous age. To account for their maturation, recent authors have invoked regional subsidence, whereas early geologists invoked magmatic activity. During 12 field seasons (since 1998), we have tracked down the bitumen localities, mapped the veins and host rocks, sampled them, studied their compositions, and dated some of them. In the provinces of northern Neuquén and southernmost Mendoza, the bitumen veins are mostly sub-vertical dykes. They tend to be straight and continuous, crosscutting regional structures and strata of all ages, from Jurassic to Palaeocene. Most of the localities lie within 70 km of Tromen volcano, although four are along the Rio Colorado fault zone and another two are at the base of Auca Mahuida volcano. On both volcanic edifices, lavas are of late Pliocene to Pleistocene age. Although regionally many of the bitumen dykes tend to track the current direction of maximum horizontal tectonic stress (ENE), others do not. However, most of the dykes radiate outward from the volcanoes, especially Tromen. Thicknesses of dykes tend to be greatest close to Tromen and where the host rocks are the most resistant to fracturing. Many of the dykes occur in the exhumed hanging walls of deep thrusts, especially at the foot of Tromen. Here the bitumen is in places of high grade (impsonite), whereas further out it tends to be of medium grade (grahamite). A few bitumen dykes contain fragments of Vaca Muerta shale, so that we infer forceful expulsion of source rock. At Curacó Mine, some shale fragments contain bedding-parallel veins of fibrous calcite (beef) and these contain some bitumen, which is

  9. Dyke Swarms in Southeastern British Columbia: Mineralogical and Geochemical Evidence for Emplacement of Multiple Magma Types During Orogenic Collapse

    NASA Astrophysics Data System (ADS)

    Freeman, M.; Owen, J. P.; Hoskin, P. W.

    2009-05-01

    Eocene dyke swarms in southeastern British Columbia provide an important record of the tectonic and magmatic history of the Cordillera following orogenic collapse. New field mapping, petrographic, and geochemical data is presented for a swarm of more than thirty dykes located near the mining town of Trail, B.C. Detailed field mapping revealed that individual dykes are highly diverse, both in composition and morphology. As a group, the dykes trend northwest (average strike of 338 degrees) and dip steeply to the southwest. Their average thickness is approximately 1.5m, with a range from 4.5m to less than 1cm. Three sub-parallel dykes were mapped for a length of 2km, and exhibit irregularities in their form such as branching and offshoots that follow fractures in the country rock. Thin-section analysis shows a wide variety of rock types within the swarm, including: micro-quartz syenite, micro-syenite, micro-monzonite, latite, basalt, basaltic andesite, and lamprophyre. Texturally, these samples are consistently porphyritic and partially altered to chlorite and sericite. This alteration commonly occurs in concentric rims around phenocrysts. The samples are typically intergranular, although some display trachytic texture. Whole-rock geochemistry shows that the dykes have a wide range in composition, with SiO2 between 76.45 wt.% and 45.15 wt.% and MgO between 0.13 wt.% and 13.16 wt.%. The results also revealed that one dyke has very high values of Ni (430 ppm), Cr (1420 ppm), and Co (50 ppm), giving it a fairly primitive composition. Harker diagrams and trace element plots show three distinct groups: mafic calc-alkaline dykes, felsic calc- alkaline dykes, and minette lamprophyres. The felsic dykes are characterized by negative Eu and Sr anomalies suggesting fractionation of plagioclase feldspar, as well as pronounced negative P and Ti anomalies. The minettes are enriched in LILE and depleted in HSFE relative to the mafic dykes. The three groups do not appear to be

  10. Variscan potassic dyke magmatism of durbachitic affinity at the southern end of the Bohemian Massif (Lower Austria)

    NASA Astrophysics Data System (ADS)

    Zeitlhofer, Helga; Grasemann, Bernhard; Petrakakis, Konstantin

    2016-06-01

    Dykes in the Strudengau area (SW Moldanubian Zone, Austria) can be mineralogically divided into lamprophyres (spessartites and kersantites) and felsic dykes (granite porphyries, granitic dykes and pegmatoid dykes). Geochemical analyses of 11 lamprophyres and 7 felsic dykes show evidence of fractional crystallization. The lamprophyres are characterized by metaluminous compositions, intermediate SiO2 contents and high amounts of MgO and K2O; these rocks have high Ba (800-3000 ppm) and Sr (250-1000 ppm) contents as well as an enrichment of large-ion lithophile elements over high field strength elements, typical for enriched mantle sources with variable modifications due to fractionation and crustal contamination. This geochemical signature has been reported from durbachites (biotite- and K feldspar-rich mela-syenites particularly characteristic of the Variscan orogen in Central Europe). For most major elements, calculated fractionation trends from crystallization experiments of durbachites give an excellent match with the data from the Strudengau dykes. This suggests that the lamprophyres and felsic dykes were both products of fractional crystallization and subsequent magma mixing of durbachitic and leucogranitic melts. Rb-Sr geochronological data on biotite from five undeformed kersantites and a locally deformed granite porphyry gave cooling ages of c. 334-318 Ma, indicating synchronous intrusion of the dykes with the nearby outcropping Weinsberger granite (part of the South Bohemian Batholith, c. 330-310 Ma). Oriented matrix biotite separated from the locally deformed granite porphyry gave an Rb-Sr age of c. 318 Ma, interpreted as a deformation age during extensional tectonics. We propose a large-scale extensional regime at c. 320 Ma in the Strudengau area, accompanied by plutonism of fractionated magmas of syncollisional mantle-derived sources, mixed with crustal components. This geodynamic setting is comparable to other areas in the Variscan belt documenting an

  11. Passive kimberlite intrusion into actively dilating dyke-fracture arrays: evidence from fibrous calcite veins and extensional fracture cleavage

    NASA Astrophysics Data System (ADS)

    Basson, I. J.; Viola, G.

    2004-09-01

    Calcite veins are invariably associated with en-echelon kimberlite dyke-fracture arrays. A detailed microstructural study of veining indicates four vein types. Type I stretched or ataxial veins are defined by high aspect ratio calcite fibers that are crystallographically continuous with calcite of the kimberlite matrix wall rock, by elongated phenocrystic phlogopite with sharp crystal terminations centered on contacts between adjacent calcite fibers and by phenocrystic phlogopite that grows or extends across these veins. Type I vein mineralogy indicates syn-dilational crystallization of vein minerals in local tensional areas within the kimberlite. Vein Types II (stretched to syntaxial elongate-blocky) and III (antitaxial) indicate late crystallization vein mineral growth during subsequent or repeated dilation. Calcite fibers in Type I to Type III veins are orthogonal to the contacts of their host dykes regardless of the orientation of vein margins. Type IV calcite veins, with blocky or mosaic/polycrystalline textures, are attributed to minor post-intrusion extension, which was potentially accompanied by repeated kimberlite intrusion within a given dyke array. Syn-crystallization/syn-intrusion Type I veins and an ubiquitous dyke-parallel fracture cleavage, in a zone up to 4 m on either side of dyke contacts, suggest that en-echelon kimberlite dyke-fracture arrays occupied the approximate center of zones of active dilation within the brittle carapace of the upper crust. Type II and III veins indicate that extension or dilation continued, independently of an occupying kimberlite fluid phase, after initial intrusion. Arrested mobile hydrofracturing, under low differential stress within the upper brittle or seismic carapace of the continental crust, followed by repeated dilation of the dyke-fracture system, is proposed as a mechanism for producing the features observed in this study. The conditions constrained in this study indicate passive dyke intrusion into dilating

  12. Eocene slab breakoff of Neotethys as suggested by dioritic dykes in the Gangdese magmatic belt, southern Tibet

    NASA Astrophysics Data System (ADS)

    Ma, Xuxuan; Xu, Zhiqin; Meert, Joseph G.

    2016-04-01

    The Gangdese magmatic belt in southern Tibet demarcates an important boundary between the Indian and Eurasian plates. Due to its location and magmatic evolutionary history, it is key to understanding both the history of Neotethys closure and the Indo-Asian collisional process. This study presents new geochronological and geochemical data for dioritic dykes in the southern Gangdese magmatic belt in southern Tibet. U-Pb geochronological results reveal that the dykes were emplaced at ca. 41 Ma and thus broadly coeval with the 40-38 Ma Dazi volcanics and the 42-40 Ma Gaoligong-Tengliang basaltic dykes. Geochemically, these dykes are characterized by alkaline signature, high Mg# (57-63) and low TiO2 contents (~ 0.9-1.0), showing notable enrichment of light rare earth elements relative to the heavy rare earth elements, enrichment of incompatible elements (i.e. Cs, Rb, Ba, Th and U), and depletion of high field strength elements (i.e. Nb, Ta and Ti). In addition, a large variation of zircon εHf(t) values (- 10 to + 13) was shown, implying heterogeneity of magma sources. A heterogeneous source is also suggested by the occurrence of xenocrysts in the dykes. These observations suggest that the magma source of the dykes was dominated by partial melting of lithospheric mantle and then subsequently contaminated by crustal material during ascent. In combination with other geological data in the region, we suspect that the slab slicing of the Neotethys played a key role in the formation of the lithospheric mantle-derived dioritic dykes and adakitic granite, asthenosphere-derived volcanics, basaltic dykes, as well as the recently reported strongly fractionated granites.

  13. The intensity of the geomagnetic field from 2.4 Ga old Indian dykes

    NASA Astrophysics Data System (ADS)

    Valet, Jean-Pierre; Besse, Jean; Kumar, Anil; Vadakke-Chanat, Sayoob; Philippe, Edouard

    2014-06-01

    paleomagnetic records from dyke swarms provide a unique source of information regarding the Archean geomagnetic field and more specifically the average field strength produced by the early dynamo. We sampled 16 paleomagnetic sites from the Dharwar giant dyke swarm in southern India which was emplaced between 2.365 and 2.368 Ga. Despite taking great care in selecting locations exempt of any geological disturbance, only two of these sites provided primary directions with very steep inclinations and therefore were emplaced in close to a magnetic pole. Paleointensity experiments were conducted on a subset of samples from the dyke margins. The characteristic magnetization is carried by single domain magnetite grains with a very narrow range of unblocking temperatures inferred from the sharp decrease by at least 75% of their remanence above 520°C. The paleointensity results indicate an average low field of 9.2 ± 7 µT, consistent with reported values from Canadian dyke swarms for the same period. These results combined with the Thellier-Thellier determinations obtained so far for the Precambrian suggest that a low field period prevailed from circa 2.3 to 1.8 Ga, while the preceding and following time intervals are characterized by significantly stronger paleointensities. Although this suite of episodes is not fully incompatible with previous models for the long-term evolution of the geodynamo, it is tempting to make the link with the recent suggestion of an early dynamo sustained within a conductive magma layer at the base of the mantle from 3.5 to 2.5 Ga which progressively declined until convection became sufficiently efficient to reactivate a strong dynamo process within the Earth's liquid core.

  14. Geochronology, Geochemistry and Petrogenesis of the Intermediate and Acid Dykes in Linzhou Basin, Southern Tibet

    NASA Astrophysics Data System (ADS)

    Dong, M.; Zhao, Z.; Zhu, D. C.; Dong, G.; Mo, X.

    2015-12-01

    The Linzizong volcanic succession (also called Linzizong Group, ~65-45 Ma), which occurred in southern Gangdese magmatic belt in response to the collision processes between India and Eurasia continents, have been well studied in the Linzhou Basin, to the northeast of Lhasa. Our research obtains some new results of zircon U-Pb, Hf isotopic data, and whole rock major and trace elements geochemical data of the intermediate (diorite porphyry) to acid (granite porphyry) dykes intruded into the Linzizong volcanics in Linzhou Basin. These dykes intruded into Dianzhong and Nianbo formations of Linzizong Group. All the samples are sub-alkaline, varying from calc-alkaline to high-K calc-alkaline series. They are peraluminous (A/CNK>1.1). The diorite porphyry, intruded in 62.4Ma with positive zircon Hf isotopes (ɛHf(t)=+5.1~+7.6), have similar composition to the andesitic rocks from Dianzhong Formation. The granite porphyries, intruded between 55.1Ma and 61.1Ma, with ɛHf(t) ranging from -1.1 to +10.4, have comparable composition with the rhyolitic Nianbo Formation. A series of evidences, including: (1) the samples have positive, mantle-like Hf feature (average ɛHf(t)=+5.9 of 86 samples); (2) wide-range variation of ɛHf(t) in samples (3.5~8.8 ɛ units in the four granite porphyries), which implying an inhomogeneous source regions; (3) magma-mixing trend in the plots of FeOT against MgO, suggesting that the magma-mixing processes that have taken place in the southern Gangdese belt, can also be applied to explain the origin of these dykes in Linzhou Basin. The dykes intruded coeval or shortly later than their equivalent volcanic rocks (Dianzhong and Nianbo formations), are in the transitional settings from subduction of Tethyan oceanic crust to the collisional between India and Eurasia continents.

  15. Integrating WorldView-2 imagery and terrestrial LiDAR point clouds to extract dyke swarm geometry: Implications for magma emplacement mechanisms

    NASA Astrophysics Data System (ADS)

    Ni, Nina; Chen, Ninghua; Chen, Jianyu; Liu, Mingliang

    2016-01-01

    Dyke geometries are useful indicators of the palaeostress field during magma emplacement. In this paper, we present a multi-scale extraction method of dyke geometries by integrating WorldView-2 (WV2) imagery and terrestrial light detection and ranging (LiDAR) data. Color composite and fusion WV2 images with 0.5-m resolution were generated by using the Gramm-Schmidt Spectral Sharpening approach, which facilitates the discrimination of dyke swarms and provides the ability to measure the orientation, exposed length, and thickness of dykes in sub-horizontal topographic exposures. A terrestrial laser scanning survey was performed on a sub-vertical exposure of dykes to obtain LiDAR data with point spacing of ~ 0.02 m at 30 m. The LiDAR data were transformed to images for extracting dyke margins based on image segmentation, then the dyke attitudes, thicknesses, and irregularity of dyke margins were measured according to the points on dyke margins. This method was applied at Sijiao Island, Zhejiang, China where late Cretaceous mafic dyke swarms are widespread. The results show that integrating WV2 imagery and terrestrial LiDAR improves the accuracy, efficiency, and objectivity in determining dyke geometries in two and three dimensions. The ENE striking dykes are dominant, and intruded the host rock (mainly granite) with sub-vertical dips. Based on the aspect ratios of the dykes, the magmatic overpressure was estimated to be less than 11.5 MPa, corresponding to a magma chamber within 6.6 km in the lithosphere.

  16. Dyking Mechanism and Melting transfer, Misho granitoid Pluton (NW of Iran)

    NASA Astrophysics Data System (ADS)

    Mehri, M.; Mohssen, M.

    2009-04-01

    Misho granitoid pluton are exposed in NW of Misho elevation and SW of Marand depression (Nw of Iran). Mineralogical paragenesis of pluton contain unhedral to sub-hedral quartz, alkaline feldspar (microcline and sub-hedral to unhedral orthoclase), two type biotites, subhedral to euhedral plagioclase (oligoclase to albite), two type zircon, magmatic epidote, sphene and apatite. Pluton, samples show geochemical characteristic of syn - to post - collisional environment, s-type granite and allocktonous. Pluton located in faulted area with Paleozoic respect dating. Source rocks of Pluton are meta - graywake and meta - pelite mixed. One type of zircon and biotite are restitic. Pluton samples have textures that indicate the effect and evidence of pressure syn - crystallization. Field geological, mineralogical and geochemical characteristic of samples from this pluton associated with enclaves riched in mica and shapes of pluton suggest quick arising and dyking mechanism as main mechanism for melt transfer. This caused restitic zircon and biotite remained, there for main mechanism of arising and generation of this pluton are dyking with propagation of fractures so that diaprism process and mechanism have very low role and effect in emplacement and melt transfer of Misho granitoid. Key Words: Misho Pluton, Restitic biotite, Arising mechanism, Dyking

  17. Dyking Mechanism and Melting transfer, Misho granitoied Pluton (NW of Iran)

    NASA Astrophysics Data System (ADS)

    Mehri, M.; Mohssen, M.; Arezoo, S.; Aram, S.

    2009-04-01

    Misho granitoid pluton are exposed in NW of Misho elevation and SW of Marand depression (In Iran). Mineralogical paragenesis of pluton contain unhedral to sub â€" hedral quartz , alkaline feldspar (microcline and sub - hedral to unhedral orthoclase) , two type biotites , subhedral to euhedral plagioclase (oligoclase to albite) , two type zircon , magmatic epidote , sphene and apatite. Pluton ,s samples show geochemical charactrestic of syn â€" to post â€" collisional environment , s â€" type granite and allocktonous. Pluton located in faulted area with Paleozoic respect dating. Source rocks of Pluton are meta â€" graywake and meta â€" pelite mixed. One type of zircon and biotite are restitic. Pluton , s samples have textures that indicate the effect and evidence of pressure syn â€" crystallization. Field geological , mineralogical and geochemical characteristic of samples from this pluton associated with enclaves riched in mica and shapes of pluton suggest quick arising and dyking mechanism as main mechanism for melt transfer . this caused restitic zircon and biotite remained , There for main mechanism of arising and generation of this pluton are dyking with propagation of fractures so that diaprism process and mechanism have very low role and effect in emplacement and melt ,s transfer of Misho granitoid. Key Words: Misho Pluton , Restitic biotite , Arising mechanism , Dyking

  18. Formation of composite dykes by contact remelting and magma mingling: The Shaluta pluton, Transbaikalia (Russia)

    NASA Astrophysics Data System (ADS)

    Litvinovsky, B. A.; Zanvilevich, A. N.; Katzir, Y.

    2012-10-01

    A unique opportunity to study the source areas, from which composite dykes were injected, occurs in the Shaluta pluton, Transbaikalia, Russia. The major quartz syenite pluton was intruded by several synplutonic gabbro bodies of various sizes. Investigations of the contact zones between gabbro and host syenite showed that liquid basalt magma intruded the incompletely crystallized coarse-grained quartz syenite with T = 700-720 °C and caused contact remelting of the silicic rock at about 900-950 °C. Mechanical interaction between newly formed silicic melt and partially crystallized mafic magma resulted in extensive magma mingling. Chemical interaction was exhibited by migration of MgO, CaO, FeO∗, Sr, H2O and Cl from the basalt magma, whereas silica, alkalis, Rb and Ba migrated from the silicic refusion zone into the crystallized gabbro. Presence of melt inclusions with homogenization temperature ranging from 640 to 790 °C in quartz and attaining 850-900 °C in late clinopyroxene indicates that at least part of newly formed minerals crystallized from the hybrid melt. Mingled magmatic material was squeezed out inwards, into the host solid quartz syenite pluton and formed dyke-like apophyses that can be traced for a distance of 60-70 m from the contact zone. Apophyses have the same dimensions, structure and composition as typical composite dykes that are common in the roof pendant over the gabbro bodies and nearby the gabbro exposures.

  19. The influence of inherited structures on dyke emplacement during Gondwana break-up in southwestern Africa

    NASA Astrophysics Data System (ADS)

    Will, Thomas; Frimmel, Hartwig

    2013-04-01

    A kinematic analysis of Cretaceous and pre-Cretaceous faulting and fracturing was carried out along the west coast of Southern Africa extending from the greater Cape Town area to the Orange River and beyond into southern Namibia. This study was augmented by the geometric analysis of mainly Cretaceous mafic dykes exposed from SW Angola to the southern tip of Africa. The kinematic analysis shows that the Cretaceous rifting event that led to the opening of the modern South Atlantic was largely controlled by NW-SE and NE-SW-striking structures. In the coastal areas of South Africa the Cretaceous deformation was dominated by NE-SW extension, whereas a general E-W-oriented extension prevailed further north. Analysis of reverse and strike-slip faulting in the Gariep and western Saldania Belts shows that the Pan-African constrictional deformation in South Africa was mainly controlled by ENE-WSW- to ESE-WNW-oriented shortening. Further north, the geometry of the Odgen Rock Mylonites in Namibia is controlled by N-S-striking strike-slip faults. The geometric analysis of the orientation of the mafic dykes also points to an E-W-oriented extension direction in the coastal areas extending from southern Angola to Meob and Conception Bay in west-central Namiba and changes to a generally NE-SW-oriented extension along the west coast of South Africa. Further inland in the Damara Belt sensu strictu, the geometric analysis of dykes belonging to the Hentjes Bay-Outjo Dyke Swarm also indicates NE-SW-oriented extension but, in addition, also a strong component of NW-SE-directed extension controlled dyke emplacement. The results of this study suggest that Pan-African (or older) structural discontinuities were re-utilised during the opening of the South Atlantic in the Early Cretaceous. The extension directions associated with Cretaceous Gondwana break-up structures are subparallel to the Pan-African shortening orientations. The inherited structural anisotropies are generally parallel to

  20. The Central Atlantic Magmatic Province: Age Comparison Between the South Carolina Dykes and Morocco Lava Flows

    NASA Astrophysics Data System (ADS)

    Youbi, N.; Nomade, S.; Breutel, E.; Knight, K.

    2003-12-01

    Believed to be the largest volcanic province on Earth at more than 6000 km long and 2000 km wide, the Central Atlantic Magmatic Province (CAMP) stretches from Eastern Canada to Brazil and from Western Spain to the Ivory Coast. Due to the massive erosion and subsequent in filling of these areas since the 200 Ma rifting event, dikes and sills constitute the majority of the exposed CAMP volcanics. However, well preserved lava flows have been found in the Triassic basins of the Northeastern United States and Morocco. Despite numerous 40Ar/39Ar dating attempts, very few of the exposed CAMP volcanics have been successfully dated due to a variety of factors including; excess argon and alteration. Especially no age is available in the well-mapped but structurally complex South and North Carolina dykes swarm as well as only few scattered ages in the Moroccan Trias-Liassic basins. Our goal is to better constrain the emplacement timing of the dykes swarm but also to compare age of both intrusive and effusive rocks from the same magmatic event but separated from more than 1000 km, 200 Mys ago. Several questions continue to surround the CAMP volcanic province including its cause and emplacement mechanism. Toward that end we have collected and dated dyke samples from the Carolinas and flows in Morocco, 1000 km away and across the rift. We anticipate that a comparison of these dates will enable us to understand more about the timing between the emplacement of the flows and dykes. We have collected in South Carolina and High Atlas in Morocco 7 and 9 hand samples respectively. Specimens from South Carolina correspond to the three distinct dykes' direction NE-SW, NW-SE and NS. In Morocco, samples were collected in four sections (100 to 300 m thick) located in the High Atlas between Marrakech and Ouarzazate. From each hand sample two different transparent plagioclase fractions, 250-180 and 180 to 100 microns, were separated. We have performed step heating experiments at the Berkeley

  1. Palaeoproterozoic Indian shield in the global continental assembly: Evidence from the palaeomagnetism of mafic dyke swarms

    NASA Astrophysics Data System (ADS)

    Radhakrishna, T.; Krishnendu, N. R.; Balasubramonian, G.

    2013-11-01

    Palaeomagnetic study of Palaeoproterozoic mafic dykes in the basement along the margins of the Cuddapah basin, the largest Precambrian sedimentary basin in south India, is presented in detail for a general discussion of Palaeoproterozoic igneous activity in India. The results are compared with all earlier published data on mafic dykes in India and are integrated with recently-published high-precision U-Pb baddeleyite ages to provide a comprehensive account of Palaeoproterozoic igneous activity in India. The analysis consolidates palaeomagnetic poles for six age divisions between 2.45 and 1.85 Ga with robust statistical criteria. Our best estimates of overall mean poles from 241 dykes are situated at (1) λ = 17.7°N; Φ = 106.0°E (A95 = 9.0°; 7N = 24) at c. 2.45 Ga, (2) λ = 7.1°N; Φ = 57.2°E (A95 = 4.5°; N = 69) at c. 2.37 Ga, (3) λ = 41.6°S; Φ = 5.5°E (A95 = 5.1°; N = 34) at c. 2.22 Ga, (4) λ = 4.7°N; Φ = 343.0°E (A95 = 4.4°; N = 31) at 2.18 Ga, (5) λ = 49.2°N; Φ = 332.9°E (A95 = 4.8°; N = 24) at 1.99-1.89 Ga and (6) λ = 73.7°N; Φ = 282.6°E (A95 = 2.9°; N = 39) at 1.86 Ga. The data permit us to construct an apparent polar wander path for the Indian shield for an ~ 600 Ma interval of the Palaeoproterozoic eon (2.45-1.85 Ga). Testing and evaluation of continental reconstructions for this interval, which are mostly based on geological correlations, reveal many inconsistencies. Between 2.45 and 2.37 Ga, the Indian shield was situated at higher latitudes similar to the Yilgarn craton of Australia. It was subsequently located near the equator at 2.22, 2.18, 1.99 and 1.86 Ga. Thus, an India-Australia connection is supported during these times, but a proposed Australia-Kaapvaal link in "Zimvaalbara" and a Dharwar (India)-Slave connection in "Sclavia" or a Superior-Zimbabwe-India connection in "Superia" are inconsistent with Indian data. In addition, the close palaeomagnetic comparison between the Palaeoproterozoic dykes of Dharwar

  2. 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

  3. Late Cretaceous dacitic dykes swarm from Central Iran, a trace for amphibolite melting in a subduction zone

    NASA Astrophysics Data System (ADS)

    Nosouhian, N.; Torabi, G.; Arai, S.

    2016-05-01

    Late Cretaceous Bayazeh dyke swarm is situated in the western part of the Central-East Iranian Microcontinent (CEIM). These dykes with a dominant northeast-southwest trend occur in the Eastern margin of the Yazd block. They cross cut the Lower Cretaceous sedimentary rocks. The length of the Bayazeh dykes occasionally reaches up to the 2 km. Rock forming minerals of these dykes are plagioclase (andesine and oligoclase), amphibole (magnesio-hastingsitic hornblende, magnesio-hornblende and tschermakitic hornblende), quartz, K-feldspar (orthoclase), zircon and apatite. Secondary minerals are chlorite (pycnochlorite), albite, magnetite and calcite. The main textures are porphyritic, glomeroporphyritic and poikilitic. The felsic character of the Bayazeh dacitic dykes is shown by their high SiO2 (62.70 to 64.60 wt %) and low [Fe2O3* + MgO + MnO + TiO2] (average 4.64 wt %) contents. These dykes represent the peraluminous to metaluminous nature and their Na2O and K2O values are 5.20-7.14 and 1.51-2.59 wt %, respectively, which reveal their sodic chemistry. The trace element characteristics are the LREE enrichment relative to HREE, [La/Yb]CN = 13.27-22.99, and slightly negative or positive Eu anomaly. These geochemical characteristics associated with low Nb/La (0.16-0.25), Yb/Nd (0.04-0.05) and high Zr/Sm (37.60-58.25) ratios indicate that the melting of a metamorphosed subducted oceanic crust is occurred where the residual mineral assemblage is dominated by garnet amphibolite. The chemical compositions of the Bayazeh dykes resemble those of slab-derived tonalite-trondhjemite-granodiorite (TTG) series. They were formed by subduction of Mesozoic Neo-Tethys -related Nain and Ashin oceanic crusts.

  4. Fault and dyke detectability in high resolution seismic surveys for coal: a view from numerical modelling*

    NASA Astrophysics Data System (ADS)

    Zhou, Binzhong 13Hatherly, Peter

    2014-10-01

    Modern underground coal mining requires certainty about geological faults, dykes and other structural features. Faults with throws of even just a few metres can create safety issues and lead to costly delays in mine production. In this paper, we use numerical modelling in an ideal, noise-free environment with homogeneous layering to investigate the detectability of small faults by seismic reflection surveying. If the layering is horizontal, faults with throws of 1/8 of the wavelength should be detectable in a 2D survey. In a coal mining setting where the seismic velocity of the overburden ranges from 3000 m/s to 4000 m/s and the dominant seismic frequency is ~100 Hz, this corresponds to a fault with a throw of 4-5 m. However, if the layers are dipping or folded, the faults may be more difficult to detect, especially when their throws oppose the trend of the background structure. In the case of 3D seismic surveying we suggest that faults with throws as small as 1/16 of wavelength (2-2.5 m) can be detectable because of the benefits offered by computer-aided horizon identification and the improved spatial coherence in 3D seismic surveys. With dykes, we find that Berkhout's definition of the Fresnel zone is more consistent with actual experience. At a depth of 500 m, which is typically encountered in coal mining, and a 100 Hz dominant seismic frequency, dykes less than 8 m in width are undetectable, even after migration.

  5. Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode.

    PubMed

    Wright, Tim J; Ebinger, Cindy; Biggs, Juliet; Ayele, Atalay; Yirgu, Gezahegn; Keir, Derek; Stork, Anna

    2006-07-20

    Seafloor spreading centres show a regular along-axis segmentation thought to be produced by a segmented magma supply in the passively upwelling mantle. On the other hand, continental rifts are segmented by large offset normal faults, and many lack magmatism. It is unclear how, when and where the ubiquitous segmented melt zones are emplaced during the continental rupture process. Between 14 September and 4 October 2005, 163 earthquakes (magnitudes greater than 3.9) and a volcanic eruption occurred within the approximately 60-km-long Dabbahu magmatic segment of the Afar rift, a nascent seafloor spreading centre in stretched continental lithosphere. Here we present a three-dimensional deformation field for the Dabbahu rifting episode derived from satellite radar data, which shows that the entire segment ruptured, making it the largest to have occurred on land in the era of satellite geodesy. Simple elastic modelling shows that the magmatic segment opened by up to 8 m, yet seismic rupture can account for only 8 per cent of the observed deformation. Magma was injected along a dyke between depths of 2 and 9 km, corresponding to a total intrusion volume of approximately 2.5 km3. Much of the magma appears to have originated from shallow chambers beneath Dabbahu and Gabho volcanoes at the northern end of the segment, where an explosive fissural eruption occurred on 26 September 2005. Although comparable in magnitude to the ten year (1975-84) Krafla events in Iceland, seismic data suggest that most of the Dabbahu dyke intrusion occurred in less than a week. Thus, magma intrusion via dyking, rather than segmented normal faulting, maintains and probably initiated the along-axis segmentation along this sector of the Nubia-Arabia plate boundary. PMID:16855588

  6. Fracture mode analysis and related surface deformation during dyke intrusion: Results from 2D experimental modelling

    NASA Astrophysics Data System (ADS)

    Abdelmalak, M.; Mourgues, R.; Bureau, D.

    2012-04-01

    The analysis of surface deformation in response to approaching intrusion is important for assessing volcanic hazards. In this paper, we present results from 2D scaled models of magma intrusion, in which we discuss the propagation mode and related surface deformation during dyke growth. Our experiments consist in the injection of analogue magma (Golden syrup) into cohesive fine-grained silica powder, simulating the brittle upper crust. Using an optical image correlation technique (Particle Imaging Velocimetry), we were able to follow the surface deformation, the displacements within the country rock and to calculate strains induced by the magma emplacement. We identified two kinds of intrusion morphologies resulting from different interactions between the dyke and plastic deformations occurring in the country rock near the surface. In both morphologies, the dyke is vertical at depth. Our analysis demonstrates that both hydraulic tensile opening and shear-related propagation operate during this first stage of vertical growth. At the same time, the surface lifted up and formed a smooth symmetrical dome. Both types of morphologies differ in the upper part. During a second stage of evolution, the first type of intrusion inclined at a dip between 45 to 65°. This inclination is not caused by shear deformations and is attributed to stress rotation near the tip. Closer to the surface, the growth of the inclined sheet creates shear bands which conduct the fluid toward the surface. The surface uplift becomes asymmetric. The second type of intrusion does not rotate at depth and continues its vertical propagation by catching vertical tensile cracks. The intrusion of magma in these cracks creates horizontal stresses which are responsible for the closure of fractures and the formation of reverse faults. At the surface the dome remains symmetrical. For both intrusions, the surface uplift accelerates during the second stage and it is strongly influenced by the presence or the

  7. Quantitative analogue modelling of the surface deformation associated with cone-sheet and dyke emplacement

    NASA Astrophysics Data System (ADS)

    Guldstrand, Frank; Bjugger, Fanny; Galland, Olivier; Burchardt, Steffi; Hallot, Erwan

    2014-05-01

    Inclined cone-sheets and sub-vertical dykes constitute the two principal types of magmatic sheet intrusions produced by volcanic systems. In active volcanic systems, the emplacement of sheet intrusions causes measurable surface deformation, which is analyzed through geodetic models. Geodetic model output is classically the shape of underlying intrusions causing the surface deformation, however, the results of these models are not testable as the subsurface intrusion is not accessible. Such test would only be doable with a physical system in which both (1) the surface deformation pattern and (2) the 3D shape of the underlying intrusion are known. In addition, established geodetic models only consider static magma intrusions, and do not account for emplacement and propagation processes. This would require combined good time- and space-resolution, which is not achievable with classical geodetic monitoring systems. We present a series of analogue models that may be a way of accurately linking surface deformation to the underlying intrusions and associated emplacement processes. We systematically varied depth of intrusion, the cohesive properties of the silica powder representing the country rock and the velocity of injected magma. The pressure of the intruding vegetable oil was measured through time, and the model surface topography was monitored. The low viscosity magma was simulated by molten vegetable oil, which solidified after intrusion; the solidified intrusion was then excavated and its shape was measured. By linking the development of the surface uplift in height, area, and volume with the pressure data from the onset of intrusion until the time of eruption, we identify characteristic laws of surface deformation. First results indicate that the pattern of uplift over time varies, depending on whether deformation is caused by a dyke- or a cone-sheet-shaped intrusion. The results from all experiments may enable us to distinguish the two intrusion types using

  8. Les dykes basiques du massif ancien de l'Ourika (Atlas de Marrakech, Maroc): géochimie et significationThe basic dykes of the Ourika old massif (High Atlas of Marrakech): Geochemistry and significance

    NASA Astrophysics Data System (ADS)

    Barakat, Ahmed; Marignac, Christian; Bouabdelli, Mohamed

    The Precambrian massif of Ourika is crosscut by two systems of basic dykes, striking N40°E and N90-120°E. Using incompatible trace elements, the two systems form two distinct chemical groups, displaying a continental tholeiitic affinity. The composition variations between the two defined groups can be due to heterogeneities of mantle sources and to contamination, during the magma ascent, by the continental crust. The emplacement of these basic dykes, before the late-PIII formations, can be related to the Neoproterozoic distension generalised to the Anti-Atlas chain. To cite this article: A. Barakat et al., C. R. Geoscience 334 (2002) 827-833.

  9. Carbonate dykes associated with Arch˦an lode-Au mineralisation, Barberton greenstone belt, South Africa

    NASA Astrophysics Data System (ADS)

    Schürmann, L. W.; Ward, J. H. W.; Horstmann, U. E.; Jordaan, L. J.; Eaton, B.

    2000-02-01

    Carbonate dykes, exposed within the Barberton greenstone belt, display geochemical signatures similar to altered carbonatite. The trace element signature normalised to primordial mantle, and the chondrite-normalised REE trends of the Ulundi Dyke display geochemical similarities to carbonatites. In addition, stable isotope results from the Ulundi Dyke (δ13Cwhole rock and δ18Owhole rock range from -3.7 to -4.9‰ and 12.8 to 13.2‰, respectively) are similar to values found for samples of wall rock and vein carbonate from Arch˦an Au-quartz-carbonate-sulphide vein systems studied in the Barberton greenstone belt. Although the data do not plot in the field of primary igneous carbonatite, they are similar to data of deuterically-altered carbonatite. These associations strengthen the deduction that Iode-Au mineralised fractures and shear zones in the Barberton greenstone belt were open to mantle-tapping fundamental faults.

  10. Magma storage and evolution in the Henties Bay-Outjo dyke swarm, Namibia -feeder systems of the Etendeka lavas

    NASA Astrophysics Data System (ADS)

    Keiding, J. K.; Frei, O.; Renno, A.; Veksler, I. V.; Trumbull, R. B.

    2012-04-01

    At the roots of continental flood basalts in the Paraná-Etendeka province are mafic dyke swarms that cover areas of several hundred kilometers. Studies of these dykes have focused mainly on the age, paleomagnetic properties and geochemistry, but less on pressure (P) and temperature (T) conditions of emplacement. However, the P and T conditions under which dyke magmas are stored are crucial for models of magma plumbing systems in flood basalt provinces. The erupted lavas are typically far from primitive compositions and generally show evidence for strong crustal assimilation in addition to magma fractionation. Unknown is where this magma modification took place in the crust. This is the kind of information that dyke studies can provide. The Henties Bay Outjo dyke swarm (HOD) in NW Namibia is the subject of this study. This is inarguably the best exposed of major dyke swarms associated with South Atlantic rifting and breakup and its geochemical diversity is well documented but aspects relating to the magma dynamics in the dyke swarm have not been studied before. Our approach is to use geochemical data from selected dykes to assess the differentiation and assimilation history of the magmas, and combine that with petrologic constraints on the temperature-pressure conditions of crystallization derived from mineral-melt equilibria. We have determined P-T estimates from olivine-melt and clinopyroxene-melt equilibria using analysis of phenocrysts by electron microprobe and applying the thermodynamic relations from Putirka (2008), who considered the standard error to be 1.7 kbar and 30°C. The calculations reflect only mineral-melt (proxied by whole-rock) compositions that are consistent with equilibrium. Crystallization temperatures range from 1040°C to 1350°C with a mean (n=58) of 1170 °C. These T-variations are not random, the high-temperature results come from a specific region of dyke emplacement but the reason for this is not yet clear. Olivine-melt temperatures

  11. New U-Pb ages from dykes cross-cutting the Demirci metamorphics, NW Turkey: Implications for multiple orogenic events

    NASA Astrophysics Data System (ADS)

    Sen, Fatih; Koral, Hayrettin; Peytcheva, Irena

    2016-04-01

    A high-grade metamorphic sequence in the Sünnice Mountains, Bolu, NW Turkey, is represented by migmatitic quartzo-feldspathic gneisses in amphibolite facies called the Demirci metamorphics/paragneisses, and a sequence of low-grade meta-volcanics containing meta-andesites with minor meta-rhyolites and meta-sedimentary rocks called the Yellice meta-volcanics. They are intruded by the Dirgine granite with an age of Upper Ediacaran (576-565 Ma) and are considered a part of the İstanbul-Zonguldak Tectonic Unit. The Demirci paragneisses are also intruded by a number of dykes in various directions, traditionally considered without radiometric dating to have been emplaced in a single magmatic phase in the Eocene related to post-collision regime of the Anatolide-Tauride platform. Mafic-intermediate-felsic dykes cross-cutting the Demirci paragneisses have been investigated in maps of 1/1000 scale, and their U-Pb zircon age, major-trace element and kinematic data have been obtained. The mafics dykes cross-cutting the Yellice meta-volcanics, equivalents of those in the Demirci paragneisses, occur in N400-500E orientations and have calc-alkaline basalt compositions with a subduction signature. The intermediate dykes occur in N650W, N800W orientations and have calc-alkaline basaltic andesite to andesitic compositions with a subduction signature. Some felsics occur in N150W and N800E orientations and have calc-alkaline dacitic compositions with a collisional tectonic setting. Other calc-alkaline granitic dykes occur in N750E orientation and calc-alkaline granitic compositions with a subduction signature. U-Pb LA-ICP-MS dating of zircons yield ages from 485.7±3.6 Ma (i.e. Cambro-Ordovician) for N800E trending dacite dykes; 443.0±5.4 Ma (i.e. Ordovician-Silurian) for N150W trending dacite dykes; 301.0±1.6 Ma (i.e. Upper Pennsylvanian-Carboniferous) for N650W trending basaltic andesite dykes; 268.2±2.4 Ma (i.e. Guadalupian-Permian) for N40-500E trending basalt dykes; 262.9±3

  12. AMS significance of dykes and granite from a same pluton - An example from the French Massif Central

    NASA Astrophysics Data System (ADS)

    Talbot, J.-Y.; Chen, Y.; Faure, M.

    2003-04-01

    The relationships between plutons and dykes of granite have been the topic of many studies since the hypothesis of "dyke propagation" was proposed as the main mode of ascent and emplacement of granitic plutons. However, most of observed pluton-related dykes can not be interpreted as "feeder dykes" but are fed by the magma chamber. Nevertheless, few AMS studies were carried out in both a pluton and its associated dykes to evaluate their internal fabrics. In the Cévennes area (SE of the French Massif Central), the Aigoual -- Saint-Guiral -- Liron granitic pluton consists of two cogenetic granitic facies. The main body is a porphyritic granodiorite facies which is common in the plutons of the Cévennes area. In the northern part of the pluton, a dyke swarm develops in the continuation of the porphyritic facies. Those NE-SW-trending dykes are composed of microgranite with locally porphyritic texture. This pluton intrudes metamorphic units dated at ca. 340--330 Ma and related to a N-S-trending shortening event. The emplacement of the pluton dated at ca. 310 Ma occured during the late-orogenic extension of the Hercynian belt. This extension is characterized by an E-W to NW-SE-trending stretching. An AMS study was carried out on the two granitic facies of this pluton. As shown by surveys of magnetic mineralogy, such as thermomagnetism, hysteresis loops, bulk magnetic susceptibility measurements, microscopic observations, the paramagnetic minerals, that is biotite with amphibole in traces, are the main carriers of the AMS for the two facies. Microstructures indicate the lack of significant solid-state deformation in both facies suggesting that AMS fabric is of magmatic origin and that no deformation is recorded after the complete crystallisation of the magma. In the porphyritic facies, the AMS fabric pattern is characterized by an E-W to NW-SE-trending lineation with shallow or moderate plunges mainly eastward. In general, magnetic foliations dip moderately eastward. This

  13. Satellite-based observations of unexpected coastal changes due to the Saemangeum Dyke construction, Korea.

    PubMed

    Lee, Yoon-Kyung; Ryu, Joo-Hyung; Choi, Jong-Kuk; Lee, Seok; Woo, Han-Jun

    2015-08-15

    Spatial and temporal changes around an area of conventional coastal engineering can be easily observed from field surveys because of the clear cause-and-effect observable in the before and after stages of the project. However, it is more difficult to determine environmental changes in the vicinity of tidal flats and coastal areas that are a considerable distance from the project. To identify any unexpected environmental impacts of the construction of Saemangeum Dyke in the area, we examined morphological changes identified by satellite-based observations through a field survey on Gomso Bay tidal flats (15km from Saemangeum Dyke), and changes in the suspended sediment distribution identified by satellite-based observations through a hydrodynamic analysis in the Saemangeum and Gomso coastal area. We argue that hydrodynamic changes due to conventional coastal engineering can affect the sedimentation pattern in the vicinity of tidal flats. We suggest that the environmental impact assessment conducted before a conventional coastal engineering project should include a larger area than is currently considered. PMID:26104827

  14. Broad accommodation of rift-related extension recorded by dyke intrusion in Saudi Arabia

    USGS Publications Warehouse

    Pallister, J.S.; McCausland, W.A.; Jonsson, Sigurjon; Lu, Zhiming; Zahran, H.M.; El, Hadidy S.; Aburukbah, A.; Stewart, I.C.F.; Lundgren, P.R.; White, R.A.; Moufti, M.R.H.

    2010-01-01

    The extensive harrat lava province of Arabia formed during the past 30 million years in response to Red Sea rifting and mantle upwelling. The area was regarded as seismically quiet, but between April and June 2009 a swarm of more than 30,000 earthquakes struck one of the lava fields in the province, Harrat Lunayyir, northwest Saudi Arabia. Concerned that larger damaging earthquakes might occur, the Saudi Arabian government evacuated 40,000 people from the region. Here we use geologic, geodetic and seismic data to show that the earthquake swarm resulted from magmatic dyke intrusion. We document a surface fault rupture that is 8 km long with 91 cm of offset. Surface deformation is best modelled by the shallow intrusion of a north-west trending dyke that is about 10 km long. Seismic waves generated during the earthquakes exhibit overlapping very low- and high-frequency components. We interpret the low frequencies to represent intrusion of magma and the high frequencies to represent fracturing of the crystalline basement rocks. Rather than extension being accommodated entirely by the central Red Sea rift axis, we suggest that the broad deformation observed in Harrat Lunayyir indicates that rift margins can remain as active sites of extension throughout rifting. Our analyses allowed us to forecast the likelihood of a future eruption or large earthquake in the region and informed the decisions made by the Saudi Arabian government to return the evacuees.

  15. Monazite in Mafic Dykes from the Bastar Craton, India: Implications for LREE Depletion in Martian Basalts

    NASA Astrophysics Data System (ADS)

    Herd, C. D.; French, J. E.; Chacko, T.; Heaman, L. M.; Borg, L. E.

    2004-05-01

    multiple generations of mafic dyke swarms, and the emplacement age of one major swarm of tholeiite dykes has now been well established at ~1.9 Ga (French et al. 2004). In searching for minerals suitable for chemical and isotopic dating, a number of late-crystallizing accessory phases were found in these dykes including zircon, baddeleyite, zirconolite, allanite, and monazite. We interpret the monazite to be a primary magmatic phase on the basis of its euhedral morphology, and its occurrence as an inclusion in undoubtedly magmatic clinopyroxene. Furthermore, its Th-U-Pb chemical age is within error of emplacement ages determined for this dyke swarm, indicating that the monazite is not xenocrystic in origin. LREE-oxide concentrations in the monazite are up to 65 wt%, corresponding to ~105 to 106X CI for La-Nd and ~104X CI for Sm-Gd. Nd is fractionated from Sm by a factor of 2; La/Sm~11 and La/Gd~55. As these enrichments are crystal-chemical in nature (cf. whole-rock REE ~100X CI; La/Sm~2; Srivastava and Singh 2003), the monazite from the Bastar dykes represents a phase capable of fractionating LREE from M-HREE in mafic systems. Recognizing that studies of the stability of monazite in mafic systems at mantle pressures are required to test this hypothesis, we speculate that accessory monazite represents a possible candidate for the fractionation of LREE from M-HREE in the martian basalts.

  16. Geochronological and geochemical constraints on the petrogenesis and tectonic significance of Paleozoic dolerite dykes in the southern margin of Alxa Block, North China Craton

    NASA Astrophysics Data System (ADS)

    Duan, Jun; Li, Chusi; Qian, Zhuangzhi; Jiao, Jiangang

    2015-11-01

    Dolerite dykes are common in the southern margin of Alxa Block which is the westernmost part of North China Craton. The ages and petrogenesis of the dolerite dykes, which are important for a better understanding of tectonic-magmatic evolution in the region, are uncertain. This paper reports the results of an integrated geochronological and geochemical study of the dolerite dykes in the Jinchuan area. Previously, these dolerite dykes were considered to be coeval with the ∼831 Ma Jinchuan ultramafic intrusion by some researchers, despite a cross-cutting relationship for the dykes. Our new zircon U-Pb dating indicates that the dolerite dykes were emplaced at ∼424 Ma, >400 Ma younger than the Jinchuan intrusion. The Jinchuan dolerite dykes contain 5-9 wt.% MgO and 47-51 wt.% SiO2, and are characterized by light REE (rare earth elements) enrichments relative to heavy REE, pronounced negative Nb anomaly, elevated initial 87Sr/86Sr from 0.7056 to 0.7068, negative εNd from -2 to -5, and zircon εHf from -2 to -20. The trace element and isotope data are consistent with an asthenosphere-derived parental magma that experienced 10-25% crustal contamination prior to final emplacement. Since the Jinchuan dolerite dykes are 20-40 Ma younger than the subduction-related basaltic volcanic rocks, blueschists and eclogites in the nearby North Qilian orogenic belt to the south, we propose that the Jinchuan dolerite dykes are the products of basaltic magmatism induced by delamination of previously subducted oceanic lithosphere and the associated asthenosphere upwelling in a post-subduction setting. The occurrence of ∼424 Ma post-subduction dolerite dykes in the Jinchuan area and the ∼450 Ma arc basalts to the south indicate that the southwestern margin of North China Craton was an active plate margin in Early Paleozoic.

  17. The need for empirically derived permeation data for personal protective equipment: the death of Dr. Karen E. Wetterhahn.

    PubMed

    Blayney, M B

    2001-02-01

    Personal protective equipment (PPE) is an essential component in any occupational health and safety program. The appropriate selection and use of PPE can help prevent or limit exposure to hazardous materials. The inappropriate selection or use of PPE can lead to unnecessary exposure or --with extremely hazardous materials--serious harm including death. In 1997, Dr. Karen E. Wetterhahn died from mercury poisoning resulting from a single exposure to dimethylmercury almost a year before. Her death raised numerous questions as to how this tragedy occurred and what could be done to protect against a chemical as dangerous as dimethylmercury. This article provides a brief review of the case and discusses the glove permeation testing done during the course of the accident investigation. Using this case as an example, the author argues that all recommendations for PPE be based on empirical testing using accepted methods and that this information be readily available. PMID:11217716

  18. Linking Magma Dynamics in Dykes and Geophysical Observations: Study on the Effect of Geometrical Setting

    NASA Astrophysics Data System (ADS)

    Vassalli, M.; Montagna, C. P.; Giudice, S.; Papale, P.; Saccorotti, G.; Longo, A.

    2009-12-01

    Understanding and thus being able to detect underground magma movement inside dykes is of primary importance for the evaluation of the short term hazard at active volcanoes, especially those characterized by frequent eccentric eruptions such as Mount Etna (Italy), Kilauea and Mauna Loa (Hawaii), Nyamulagira and Nyiragongo (D.R.C.), Piton de la Fournaise (Reunion), as well as many others in the world. Magmatic fluid motion is often accompanied by distinctive low frequency seismic signals, the characteristics of which relate in complex ways to several features of the system including the geometry of the system in which fluid motion takes place, the viscosity of the fluid and the flow regime, and the properties of the surrounding rock system. We have performed a numerical simulation study to investigate the control exerted by dyke geometry on the magma flow dynamics and the associated ground displacement and seismic signals. Magma flow dynamics are simulated through the code GALES (Longo et al., 2006), which solves the two dimensional transient dynamics of multi-component fluids in compressible to incompressible regimes. The simulated systems represent volcanic dykes having different geometries from vertical with smooth walls to inclined with protrusions and indentations. The initial configuration is gravitationally unstable: a CO2-richer, lighter magma lies below a CO2-depleted, denser magma. Forced convection is induced in the system destabilizing the surface interface between the two magmas. The output of the fluid dynamics numerical simulations in terms of space-time stress distribution at the fluid-rock interface is propagated through the hosting rock medium in order to obtain synthetic seismic signals and displacement at the Earth surface. Wave propagation is performed by means of analytical Green function integration in an homogeneous half space, in order to underline the basic differences due exclusively to the geometric setting of the systems under

  19. Age and depositional setting of the Permian Black Dyke Formation: Implications for the paleogeography and structural evolution of western Nevada

    NASA Astrophysics Data System (ADS)

    Bleina, O.; Lapierre, H.; Schweickert, R. A.; Pêcher, A.; Monié, P.; Maluski, H.; Charvet, J.

    1999-09-01

    In western Nevada, the Black Dyke Formation includes volcanic rocks overlain conformably by volcaniclastic sediments. At the base, hornblende-phyric basalts with cognate hornblende-bearing gabbroic cumulates are interbedded with tuffs and pyroclastic breccia. Amphiboles give 40Ar/ 39Ar ages of 276 Ma. Clinopyroxene-phyric pillow basalts and plagioclase-phyric andesitic lava flows are present higher in the section. Facies changes between exposures reflect development near volcanic centers. According to our investigations, the Black Dyke Formation is involved in east-west-trending folds overturned toward the south, and overlain unconformably by the Mesozoic Dunlap Formation, which unconformably overlies the Mississippian-Permian Mina Formation. Interpreted until now as tectonic slices within the Luning allochthon, we suggest that the Black Dyke Formation is part of the Sonoma allochthon associated with the Mina Formation. The Sonoma records closure of the Havallah basin (Golconda allochthon), and collision of an arctrench system with the North American margin. The Black Dyke Formation exhibits similarities with the Permian arc sequence of the northern Sierra Nevada. Both sequences are characterized by amphibole-bearing breccias, clinopyroxene-phyric pillow-basalts, plagioclase-phyric andesites and overlying volcaniclastic sediments. These sequences developed in the same geodynamic environment (an islandarc).

  20. Surface deformation and stress interactions during the 2007-2010 sequence of earthquake, dyke intrusion and eruption in northern Tanzania

    NASA Astrophysics Data System (ADS)

    Biggs, Juliet; Chivers, Michael; Hutchinson, Michael C.

    2013-10-01

    Magma movement and fault slip alter the magnitude and orientation of the stress in the surrounding crust. Observations of a sequence of events clustered in space and time provide information about the triggering mechanism and stress interactions between magma intrusion, earthquakes and eruptions. We investigate the syn- and post-intrusion stress changes associated with the 2007 Gelei dyke intrusion episode and subsequent eruption of nearby Oldonyo Lengai. Previous studies produced a kinematic model of the 2007 June-August sequence involving ˜1 m slip on a normal fault followed by the intrusion of the 7-10-km long Gelei dyke, collapse of a shallow graben and the deflation of the Gelei magma chamber. Immediately following this, the volcano Oldoinyo Lengai (<10 km away) experienced a new phase of explosive activity lasting for several months. Here, we present new geodetic observations covering Gelei and Oldoinyo Lengai in 2008 September-2010. We show continued slip on graben-bounding faults above the Gelei dyke. The eruption of Oldoinyo Lengai was accompanied by the intrusion of a 4 km-long E-W-trending dyke followed by deflation of a shallow source directly below the summit of the volcano. Next, we use stress calculations to investigate a number of hypotheses linking these events. (1) Before the onset of surface deformation, a dyke sufficiently deep and narrow to be geodetically undetectable could still have produced sufficient stress changes to trigger slip on the normal fault (i.e. the sequence could have been magmatically driven). (2) Stresses at the dyke tip would have been sufficient to overcome the effect of continued slip on the normal fault, allowing the dyke to propagate upwards into a region of clamping. (3) The Gelei sequence would have produced a significant stress change on the chamber beneath Oldoinyo Lengai. These static stress calculations allow us to discuss the roles played by dynamic stress, deeper magmatic changes and background stresses

  1. Composition of the Tarim mantle plume: Constraints from clinopyroxene antecrysts in the early Permian Xiaohaizi dykes, NW China

    NASA Astrophysics Data System (ADS)

    Wei, Xun; Xu, Yi-Gang; Luo, Zhen-Yu; Zhao, Jian-Xin; Feng, Yue-Xing

    2015-08-01

    Numerous alkaline basaltic dykes crosscut the Early Permian Xiaohaizi wehrlite in drill-cores and syenite intrusion in the Tarim large igneous province, NW China. One basaltic dyke contains abundant clinopyroxene macrocrysts with strong resorption textures. Such a textural disequilibrium is consistent with their contrasting chemistry between the macrocrysts (Mg# = 80-89) and the host dyke (Mg# = 39, corresponding to Mg# = 73 of clinopyroxene in equilibrium with the dyke), indicating that they are not phenocrysts. The clinopyroxene macrocrysts are characterized by low TiO2 (0.26-1.09 wt.%), Al2O3 (1.15-3.10 wt.%) and Na2O (0.16-0.37 wt.%), unlike those in mantle peridotites but resembling those in layered mafic intrusions in the same area. The clinopyroxene macrocrysts and the clinopyroxenes from the Xiaohaizi cumulate wehrlites define a coherent compositional trend and have identical trace element patterns, pointing to a comagmatic origin for these crystals. Accordingly, the macrocrysts cannot be xenocrysts foreign to the magmatic system. Rather they are antecrysts that crystallized from progenitor magmas and have been reincorporated into the host dyke before intrusion. The 87Sr/86Sri (0.7035-0.7037) and εNdi (4.5-4.8) of the clinopyroxene macrocrysts with high Mg# (80-89) are apparently lower and higher than their respective ratios of the clinopyroxenes in the wehrlites (Mg# = 75-84, 87Sr/86Sri = 0.7038-0.7041, εNdi = 1.0-1.9). This difference in isotopes can be accounted for by assimilation and fractional crystallization (AFC) process operated during the formation of the Xiaohaizi intrusion. In this sense, the clinopyroxene macrocrysts record the composition of the uncontaminated Tarim plume-derived melts.

  2. Dyke propagation and tensile fracturing at high temperature and pressure, insights from experimental rock mechanics.

    NASA Astrophysics Data System (ADS)

    Bakker, Richard; Benson, Philip; Vinciguerra, Sergio

    2014-05-01

    It is well known that magma ascends trough the crust by the process of dyking. To enable dyke emplacement, basement rocks typically fail in a mode 1 fracture, which acts as conduits for magma transport. An overpressure of the ascending magma will further open/widen the fracture and permit the fracture to propagate. In order to further understand the emplacement and arrest of dykes in the subsurface, analogue and numerical studies have been conducted. However, a number of assumptions regarding rock mechanical behaviour frequently has to be made as such data are very hard to directly measure at the pressure/temperature conditions of interest: high temperatures at relatively shallow depths. Such data are key to simulating the magma intrusion dynamics through the lithologies that underlie the volcanic edifice. Here we present a new laboratory setup, which allows us to investigate the tensile fracturing properties under both temperature and confining pressure, and the emplacement of molten material within the newly formed fracture. We have modified a traditional tri-axial test assembly setup to be able to use a Paterson type High Pressure, High Temperature deformation apparatus. Sample setup consists of cylindrical rock samples with a 22 mm diameter and a 8 mm bore at their centre, filled with a material chosen as such that it's in a liquid state at the experimental temperature and solid at room temperature to enable post-experiment analysis. The top and lower parts of the rock sample are fitted with plugs, sealing in the melt. The assembly is then placed between ceramic pistons to ensure there are no thermal gradients across the sample. The assembly is jacketed to ensure the confining medium (Ar) cannot enter the assembly. A piston is driven into the sample such that the inner conduit materials pressure is slowly increased. At some point a sufficient pressure difference between the inner and outer surfaces causes the sample to deform and fail in the tensile regime

  3. Strain accommodation by slow slip and dyking in a youthful continental rift, East Africa.

    PubMed

    Calais, Eric; d'Oreye, Nicolas; Albaric, Julie; Deschamps, Anne; Delvaux, Damien; Déverchère, Jacques; Ebinger, Cynthia; Ferdinand, Richard W; Kervyn, François; Macheyeki, Athanas S; Oyen, Anneleen; Perrot, Julie; Saria, Elifuraha; Smets, Benoît; Stamps, D Sarah; Wauthier, Christelle

    2008-12-11

    Continental rifts begin and develop through repeated episodes of faulting and magmatism, but strain partitioning between faulting and magmatism during discrete rifting episodes remains poorly documented. In highly evolved rifts, tensile stresses from far-field plate motions accumulate over decades before being released during relatively short time intervals by faulting and magmatic intrusions. These rifting crises are rarely observed in thick lithosphere during the initial stages of rifting. Here we show that most of the strain during the July-August 2007 seismic crisis in the weakly extended Natron rift, Tanzania, was released aseismically. Deformation was achieved by slow slip on a normal fault that promoted subsequent dyke intrusion by stress unclamping. This event provides compelling evidence for strain accommodation by magma intrusion, in addition to slip along normal faults, during the initial stages of continental rifting and before significant crustal thinning. PMID:19079058

  4. Complex Dyke Emplacement at the Hyper-Inflated EPR 16°N Segment

    NASA Astrophysics Data System (ADS)

    Dyment, J.; Deschamps, A.; Gente, P.; Agranier, A.; Aquilon-Robles, A.; Benoit, M.; Hémond, Ch.; Janin, M.; Maia, M.; Rodrigues-Leon, L.; Szitkar, F.; Thibaud, R.; Tilot, V.; Parisub Scientific Party

    2010-12-01

    neovolcanic zone. To this end, we have used the magnetic data, adequately corrected for the effect of the AUV and reduced to total field anomaly. The resulting magnetic map shows a set on negative anomalies associated to some - but not all - grabens and help to discriminate between recently active and inactive grabens. Indeed, such negative anomalies have already been observed by Shah et al. (JGR, 2003) on the EPR at 17°28’S and 18°37’S and interpreted as marking the presence of hot dyke swarms, warmer than the Curie temperature, and the associated demagnetization of nearby basalt. Forward modelling by these authors suggests that such an anomaly can remain during about century. On the EPR 16°N, the presence of several anomalies suggests that, in some areas, several dyke swarms are “simultaneously” active (at the scale of a century). The intensity of these anomalies may reflect the size and/or the age of the dyke swarms, the stronger anomalies corresponding to the larger and/or the hottest (and therefore most recent) dykes.

  5. Adult Presentation of Dyke-Davidoff-Masson Syndrome: A Case Report

    PubMed Central

    Roy, Ujjawal; Panwar, Ajay; Mukherjee, Adreesh; Biswas, Debsadhan

    2016-01-01

    Dyke-Davidoff-Masson syndrome (DDMS) is a rare disease which is clinically characterized by hemiparesis, seizures, facial asymmetry, and mental retardation. The classical radiological findings are cerebral hemiatrophy, calvarial thickening, and hyperpneumatization of the frontal sinuses. This disease is a rare entity, and it mainly presents in childhood. Adult presentation of DDMS is unusual and has been rarely reported in the medical literature. Key Messages DDMS is a rare disease of childhood. However, it should be kept in mind as a diagnostic possibility in an adult who presents with a long duration of progressive hemiparesis with seizures and mental retardation. Cerebral hemiatrophy, calvarial thickening, and hyperpneumatization of the frontal sinuses are diagnostic for this illness on brain imaging. PMID:26933427

  6. Dyke-davidoff-masson syndrome: cases of two brothers and literature review.

    PubMed

    Park, Kyung-Il; Chung, Jae-Myun; Kim, Ji-Young

    2014-06-01

    Dyke-Davidoff-Masson syndrome (DDMS) has cerebral hemiatrophy and compensatory ipsilateral skull thickening, and is manifested by recurrent seizures and hemiparesis. We present one case with typical DDMS, who had a brother suffering from epilepsy with mild imaging abnormality relevant to DDMS and similar seizure semiology. A 26-year-old man had a history of developmental delay, mental retardation, hemiparesis and recurrent seizures. His brother, 23-year-old man had also experienced recurrent seizures, but he had no neurological deficits. Older brother experienced focal motor seizures with/without secondary generalization. Sometimes, he noted an auditory aura. MRI demonstrated the hemispheric atrophy with the adjacent bony hypertrophy. The seizures of younger brother were mainly of the auditory type and the MRI showed mild hemispheric atrophy with hippocampal sclerosis without any bony change. Our sibling cases might have a familial predisposition and support the idea that clinical courses and radiological findings of DDMS are varied even within one family. PMID:24977128

  7. Dyke-Davidoff-Masson Syndrome. An unusual cause of status epilepticus.

    PubMed

    Zawar, Ifrah; Khan, Ashfa A; Sultan, Tipu; Rathore, Ahsan W

    2015-10-01

    The Dyke-Davidoff-Masson Syndrome (DDMS) results from an insult to the growing brain in utero or early infancy, which lead to loss of neurons compromising the growth of the brain. Clinical presentation includes seizures, hemiparesis, facial asymmetry, and learning disability. Radiological findings include cerebral atrophy on one side. Here, we present a case with status epilepticus who had underlying DDMS. It is a rare syndrome and uncommon cause for status epilepticus. Infections of CNS, hypoxic ischemic encephalopathy, intracranial bleed, trauma, congenital vascular malformations are the common causes of this syndrome. Diagnosis is established after clinical history, examination, and MRI. Intractable seizures can be controlled with appropriate anticonvulsants. Subsequently, these children may require physiotherapy, speech therapy, and occupational therapy in addition to the anticonvulsant medication. Outcome is better if the seizures are controlled. PMID:26492121

  8. Ages of Zircons from Basalt of Erdaogou Formation and Diabase Dyke Swarms in Northern Liaoning

    NASA Astrophysics Data System (ADS)

    SONG, Biao; QIAO, Xiufu

    The drainage area of Fanhe River around the Tieling City in the northern part of Liaodong Peninsula, is located in the north of the Tancheng-Lujiang fault zone, and belongs to the northeastern end of North China Block in the Sino-Korean plate. In this area, there is huge-thick basalt (Erdaogou Formation) and diabase dyke swarms, which are thought to be Mesoproterozoic basic magmatism. By means of zircon dating with sensitive high-resolution ion microprobe (SHRIMP), the eruption time of the Erdaogou Formation basalt is considered to be 36.4 ± 1.8 Ma, the Eocene Epoch. The emplacement time of the diabase swarms is considered to be 93.5 ± 1.4 Ma, the Late Cretaceous. The basic dyke swarms and basalts in the northern Liaoning were determined as Mesozoic and Cenozoic, respectively. This shows that the northern boundary that divides North China Block and Jiao-Liao-Korean Block within Sino-Korean Plate (i.e. the northern part of the Tancheng-Lujiang fault zone), was in a stretch-tensile tectonic environment in EW direction in Late Cretaceous. In addition, this tectonic environment resulted in the intrusion of the diabase swarms. In Paleogene Period, the stretching direction was changed to near SN, and the formation of the stretching tectonics led to the eruption of the huge-thick Erdaogou Formation basalt. The new SHRIMP zircon U-Pb ages in this article does not support the traditional opinion that the Erdaogou Formation basalt was formed in Mesoproterozoic.

  9. Single Silicate Crystal Paleointensity Analyses of the ca. 2.575 Ga Great Dyke of Zimbabwe

    NASA Astrophysics Data System (ADS)

    O'Brien, T.; Tarduno, J. A.; Hofmann, A.

    2014-12-01

    Recent considerations of core thermal conductivity suggest a relatively young (less than 1 billion-year-old) age for the inner core, excluding compositional convection associated with inner core growth as a driving mechanism for an Archean geodynamo. These reconsiderations provide further motivation for studying the nature of the field when core convection was predominantly related to core mantle boundary heat flow. Here we examine the ca. 2.575 Ga Great Dyke of Zimbabwe. We rely on deep drill core samples, eliminating the otherwise pervasive effects of lightning seen in surface samples. We apply single silicate crystal paleointensity (SCP) techniques (Tarduno et al., Rev. Geophys., 2006) on feldspars separated from orthopyroxene gabbros (norites). Scanning electron microscope (SEM) analyses indicate the presence of rare sub-micron equant to slightly elongate magnetic inclusions in the feldspars. The magnetite/titanomagnetite needles commonly observed in feldspars of slowly cooled igneous rocks are rarely observed in crystals from our Great Dyke gabbro samples. Selection criteria of crystals for analyses required feldspar crystals to be free of visible multi-domain inclusions. Natural remanent magnetic intensities of ca. 1 mm-sized feldspar crystal are relatively weak (approximately 1-2 x 10-8 emu), but well within the measurement range of the University of Rochester small bore ultra-high moment resolution 2G DC SQUID magnetometer. Preliminary total thermal demagnetization experiments suggest paleofield values within 50% of those of the present-day, similar to other results that imply a relatively strong magnetic field during the late Archean. Results from Thellier analyses will be used to test this interpretation.

  10. 1.99 Ga mafic dykes of the Lewisian Gneiss Complex of Scotland: An upper age limit for the Palaeoproterozoic Loch Maree Group

    NASA Astrophysics Data System (ADS)

    Baker, Thomas; Prave, Tony; Spencer, Christopher

    2015-04-01

    Mafic dyke swarms are often used as geochronological markers, as they are widespread and emplaced over short timespans. The ca. 2.4 Ga Scourie dyke swarm is one such example that has played a key role in understanding the complex tectonic and metamorphic history of the Lewisian Gneiss Complex of Scotland (LGC), part of the North Atlantic Craton (NAC). The LGC consists of Archean and Palaeoproterozoic terranes that experienced polyphase deformation prior to their assembly at ca. 1.8 Ga. Zircons separated from a doleritic dyke from the Gairloch terrane have yielded a concordant U-Th-Pb age (1,989 +4.3 / -0.99 Ma) using the ID-TIMS method. The doleritic dyke is emplaced in Lewisian gneiss that experienced both granulite and amphibolite-facies metamorphism. Partial recrystallisation and amphibolitisation of the dyke demonstrate that it pre-dates the most recent (Laxfordian) amphibolite-facies metamorphic event. The age obtained from the dyke overlaps the U-Pb age of a previously dated olivine gabbro dyke from the Assynt terrane (1,992 Ma). These combined ages provide strong corroborating evidence for a ca. 2.0 Ga mafic dyke swarm event, distinct from the older ca. 2.4 Ga Scourie dyke event known from elsewhere in the LGC. The existence of a ca. 2.0 Ga mafic dyke swarm provides an upper age limit for the Loch Maree Group (LMG), a Palaeoproterozoic succession of metasediment and metavolcanic rocks that overlie the LGC and which are not cross-cut by the Scourie dykes. This study proposes that a period of crustal extension took place in the region at ca. 2.0 Ga. Later, subduction may have resulted in the accretion of the LMG and the adjacent Ard Gneiss, which has previously been regarded as a magmatic arc. The ca. 1.9 Ga age of the earliest stage of the Laxfordian metamorphic event, which affected the LMG, could therefore mark the onset of collision. This sequence of events can be correlated with other coeval areas of the NAC, including the Nagssugtoqidian mobile belt of

  11. Post-collisional magmatism associated with Variscan orogeny in the Danubian Domain (Romanian Southern Carpathians): the Motru Dyke Swarm

    NASA Astrophysics Data System (ADS)

    Stremtan, C. C.; Campeanu, M.; Balica, C.; Ryan, J. G.; Savov, I. P.; Balintoni, I.

    2012-12-01

    The metamorphic basement of the Danubian nappe system in the Romanian Southern Carpathians is comprised of Neoproterozoic high-grade metamorphics and granitoid intrusions, underlying low-grade Ordovician to early Carboniferous formations. This entire sequence is intruded by late Variscan age (Carboniferous to early Permian) post-collisional granitoid plutons. The Motru Dyke Swarm (MDS), a geographically-extensive system of intermediate to felsic dykes crosscuts the whole Danubian basement. Zircon U/Pb results on some MDS dikes indicate a largely inherited zircon population with an age distribution pointing to Pan-African origins and a peri-Amazonian provenance for MDS crustal sources. However, in the field the MDS dykes cross-cut late Variscan post-collisional plutons, supporting the assertion that these dykes are much younger, with Upper Paleozoic, most likely Carboniferous (Variscan) ages. This study is aimed at providing a better understanding of the petrogenesis, emplacement age, and evolution of the MDS using zircon U/Pb dating, geochemical, isotope, and petrographic data. The dykes record heterogeneous petrographic and geochemical (major and trace elements, as well as radiogenic isotope) signatures. MDS dykes are mainly basaltic-andesite, andesite, trachyandesite, and dacite in composition and petrography with porphyritic basaltic andesites being the most common. The absence of olivine and the presence of brownish amphibole, biotite- and quartz-mantled zircons, as well as mm- to cm-size enclaves of meta-sediments are the most distinctive petrologic features of the MDS. Published[1] major elements compositions define a complete differentiation series, ranging from basaltic andesites to rhyolites (50-72 wt% SiO2) with medium-K to shoshonitic calc-alkaline characteristics. The dykes are dominantly metaluminous (average ASI of 0.90). Considerable heterogeneity is preserved in their trace element compositions: ΣREE ranges from 41.18 to 378, Eu/Eu* from 0.79 to 1

  12. Influence of dyke geometry on the dynamics of magma flow and associated ground displacement and seismic signals

    NASA Astrophysics Data System (ADS)

    Montagna, C. P.; Longo, A.; Vassalli, M.; Papale, P.; Saccorotti, G.; O'Brien, G.; Bean, C.

    2009-04-01

    Detecting underground magma movement in dykes is of primary importance for the evaluation of the short term hazard at active volcanoes, especially those characterized by frequent eccentric eruptions like Mount Etna (Sicily), Kilauea and Mauna Loa (Hawaii), Nyamulagira and Nyiragongo (D.R.C.), Piton de la Fournaise (Reunion), and many others in the world. Fluid motion is often accompanied by distinctive low frequency seismic signals, the characteristics of which relate in complex ways to several characteristics of the volcanic system including the geometry of the crack through which fluid motion takes place, the viscosity and the flow regime of the fluid, the elastic properties and heterogeneities of the rock system, and so on. We have undertaken a numerical simulation study to investigate the control exerted by dyke geometry on the magma flow dynamics and associated ground displacement and seismic signals. Magma flow dynamics are simulated through the code GALES (Longo et al., 2006), which solves the 2D transient dynamics of multi-component fluids in compressible to incompressible regimes. The simulated system is represented by volcanic dykes having different geometries from vertical with smooth walls to inclined with protrusions and indentations. Fluid flow is allowed to occur by considering an initial gravitationally unstable condition with CO2-rich, lighter magma placed below a CO2-poor, denser magma. Both natural convection and forced convection (with prescribed overpressure applied at dyke base) are taken into account. The output of GALES in terms of time-space stress distribution at the fluid-rock interface is employed as the boundary condition for the simulation of elastic wave propagation in the surrounding rock system. This is done by employing a numerical code based on a discrete elastic lattice method (O'Brien and Bean, 2004) which accounts for complex topography and rock heterogeneities. The numerical results illustrate the complex time

  13. A new 200 Ma paleomagnetic pole for Africa, and paleo-secular variation scatter from Central Atlantic Magmatic Province (CAMP) intrusives in Morocco (Ighrem and Foum Zguid dykes)

    NASA Astrophysics Data System (ADS)

    Palencia-Ortas, A.; Ruiz-Martínez, V. C.; Villalaín, J. J.; Osete, M. L.; Vegas, R.; Touil, A.; Hafid, A.; McIntosh, G.; van Hinsbergen, D. J. J.; Torsvik, T. H.

    2011-06-01

    Available apparent polar wander (APW) paths for the 200 Ma configuration of Pangea, just prior to the opening of the Central Atlantic Ocean, differ as much as 10o in arc length. Here, we add new data from northwest Africa for this time, obtained from the northeast-trending Foum-Zguid and Ighrem dykes (ca. 200 Ma). These dykes form part of the northern domain of the Central Atlantic Magmatic Province (CAMP), and crosscut the Anti-Atlas Ranges in Morocco, and compositionally correspond to quartz-normative tholeiites intruded in continental lithosphere shortly before the opening of the Central Atlantic Ocean. The Foum-Zguid dyke has been intensively studied, whereas the Ighrem dyke has received less scientific focus. We sampled both dykes for paleomagnetic investigation along 100 km of each dyke (12 sites for Foum-Zguid and 11 for Ighrem, 188 samples included in the final analyses). Rock magnetic experiments indicate a mixture of multidomain and single-domain magnetite and/or low-Ti titanomagnetite particles as the principal remanence carriers. In both dykes, the primary nature of the characteristic remanent magnetization is supported by positive contact tests, related to Fe-metasomatism or baked overprints of the corresponding sedimentary country rocks. The directions of the characteristic magnetization exhibit exclusively normal polarity. Site-mean virtual geomagnetic poles are differently grouped in each dyke, suggesting distinct geomagnetic secular variation records. The Foum-Zguid paleomagnetic pole (N= 12, PLat= 67.9°N, PLon= 247.9°E, κ= 125, A95= 3.9°) plots close to that of Ighrem (N= 11, PLat= 78.4°N, PLon= 238.2°E, κ= 47, A95= 6.7°), confirming those mineralogical and geochemical evidences supporting that they represent dissimilar magmatic stages. Virtual geomagnetic poles dispersion from both dykes (S= 10.5°13.0°8.1°) is in line with those obtained from recent studies of a CAMP-related dyke in Iberia and results from CAMP lavas in the Argana

  14. A system that 'walks the talk'. Using improved community health status for CEO evaluation and compensation. Interview by Karen Gardner.

    PubMed

    McMeekin, J C; Billings, R W

    1994-04-01

    Crozer-Keystone Health System, with corporate headquarters in Media, PA, is relatively new. The system was formed in 1990 to integrate four hospitals--roughly 1,160 acute care beds--five long-term care facilities, skilled nursing facilities and personal care facilities. According to President and CEO John C. McMeekin, the system comprises "very aggressive" programs in senior wellness, geriatric care, women's and children's health, behavioral medicine and psychiatric substance abuse. And it also has a large managed care organization that was undertaken as part of a joint venture with members of the hospitals' medical staff. The system is still defining itself, and perhaps that's why it has been willing to venture into an area that is virtually unique among health care organizations: using community health status indicators as part of the CEO's annual evaluation and compensation. Recently, Trustee editor Karen Gardner spoke to McMeekin and board Chairman Richard W. Billings about a major community needs assessment project that the system undertook in 1991 and how it is using the results of that study. PMID:10133272

  15. Methamphetamine use and correlates in two villages of the highland ethnic Karen minority in northern Thailand: a cross sectional study

    PubMed Central

    2009-01-01

    Background The prevalence of methamphetamine use and human immunodeficiency virus (HIV) incidence are high in lowland Thai society. Despite increasing social and cultural mixing among residents of highland and lowland Thai societies, however, little is known about methamphetamine use among ethnic minority villagers in the highlands. Methods A cross-sectional survey examined Karen villagers from a developed and a less-developed village on February 24 and March 26, 2003 to evaluate the prevalence and social correlates of methamphetamine use in northern Thailand. Data were collected in face-to-face interviews using a structured questionnaire. Results The response rate was 79.3% (n = 548). In all, 9.9% (males 17.6%, females 1.7%) of villagers reported methamphetamine use in the previous year. Methamphetamine was used mostly by males and was significantly related to primary or lower education; to ever having worked in town; to having used opium, marijuana, or heroin in the past year; and to ever having been diagnosed with a sexually transmitted infection (STI). Conclusion Since labor migration to towns is increasingly common among ethnic minorities, the prevention of methamphetamine use and of HIV/STI infection among methamphetamine users should be prioritized to prevent HIV in this minority population in Thailand. PMID:19445678

  16. Link between extension, dyking and subsidence as the reconstruction tool of intraplate rifting mechanism (backstripping data, modelling and geochronology)

    NASA Astrophysics Data System (ADS)

    Polyansky, Oleg P.; Reverdatto, Vladimir V.; Babichev, Alexey V.

    2014-05-01

    Correlation between subsidence and extension-related magmatism is key in determining mechanism of intracratonic sedimentary basins formation. The total volume of basic sheet intrusions and volcanics within sedimentary rock mass characterizes indirectly the degree of depletion and thinning of the rifted mantle lithosphere. At present the documented features of real-world intracontinental basins show a wide range of parameters characterizing the duration and rate of subsidence, degree of extension/thinning of the lithosphere, age and extent of dyking. For creation of general model of continental rifting it is important to reconstruct an evolution of basins finished at the continental stage, not entered an oceanic spreading phase. One of examples of such structure is the Vilyui sedimentary basin in the eastern Siberian Platform which includes the massive emplacements (10**5 km3) of extrusive and intrusive rocks of the Vilyui large igneous province. We combine backstripping reconstructions of sedimentation and thermal regime during the subsidence with a numerical modelling based on the deformable solid mechanics. It is the first time that the evolution of sedimentation and subsidence which is nonuniform over the basin area has been analyzed for the Vilyui basin. The rift origin of the basin is proved. We estimate the spatial distribution of the parameters of crustal and mantle-lithosphere extension as well as expansion due to dike intrusions. According to the reconstructions, the type of subsidence curves for the sedimentary rocks of the basin depends on the tectonic regime of sedimentation in individual subbasins. The backstripping analysis revealed two stages of extension (sediments 4-5 km thick) and a foreland stage (sediments >2 km thick). With the two-layered lithosphere model, we concluded that the subcrustal layer underwent predominant extension (by a factor of 1.2-2.0 vs. 1.1-1.4 in the crust). In each section, dyke-related extension due to basic intrusion is

  17. Seismic constraints on a large dyking event in Western Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Ahmed, A.; Doubre, C.; Leroy, S.; Perrot, J.; Audin, L.; Rolandone, F.; Keir, D.; Al-Ganad, I.; Khanbari, K.; Mohamed, K.; Vergne, J.; Jacques, E.; Nercessian, A.

    2012-04-01

    In November 2010, a large number of events were recorded by the world seismic networks showing important activity occurring along the western part of the Aden Ridge. West of the Shulka El Sheik transform zone, events in this large seismic swarm (magnitudes above 5) occurred in a complex area, where the change of both the ridge direction and the bathymetry suggest the propagation of the ridge into a continental lithosphere and the influence of the thermal anomaly of the Afar Hot Spot. We combine several sets of data from permanent networks and temporary 3C broad stations installed after the beginning of the event along the southern and eastern coasts of Yemen and Djibouti respectively, we located more than 600 earthquakes with magnitudes ranging from 2.5 to 5.6 that occurred during the first months following the first event. The spatial distribution of the main seismicity reveals a very clear N115°-trending alignment, parallel to the mean direction of the en-echelon spreading segments that form the ridge at this longitude. Half of the events, which represent half of the total seismic energy released during the first months, are located in the central third section of the segment. Here several volcanic cones and recent lava flows observed from bathymetric and acoustic reflectivity data during the Tadjouraden cruise (Audin, 1999, Dauteuil et al., 2001) constitute the sea floor. In addition to this main activity, two small groups of events suggest the activiation of landslides into a large fan and the activity in a volcanic area 50 km due east from the main active zone. The time evolution of the seismicity shows several bursts of activity. Some of them are clearly related to sudden activities within the volcanic areas, when others exhibit horizontal migration of the events, with velocity around ~ 1 km/h. The time-space evolution of the seismicity clearly reveals the intrusion of dykes associated with magma propagation from the crustal magmatic centres into the rift

  18. Gridino melange zone of the Belomorian eclogite province: Succession of tectonic events and structural position of mafic dyke swarms

    NASA Astrophysics Data System (ADS)

    Babarina, I. I.; Sibelev, O. S.; Stepanova, A. V.

    2014-07-01

    Based on relationships between Paleoproterozoic mafic dykes, lithotectonic complexes, and tectonic structures of the Gridino Zone in the Belomorian eclogite province of the Fennoscandian Shield, deformations have been divided into groups differing in age and the succession of tectonic events has been reconstructed. The formation of Neoarchean eclogite-bearing melange was related to disintegration of large eclogite sheets in the course of near-horizontal ductile flow accompanied by syntectonic granitoid magmatism, multiple migmatization, and granulite-to amphibolite-facies metamorphism. The exotic blocks, including eclogites, were incorporated into TTG gneisses as sheets and lenses up to a few hundreds of meters in thickness and oriented conformably with gneissic banding. As a result of ductile flow, the lithotectonic complexes were transported at the level of discrete brittle-ductile deformations expressed as strike-slip faults and associated folds. Under conditions of a relatively rigid medium, individual structural elements underwent rotation approximately through 90° in plan view. Under the extension regime in the Early Paleoproterozoic, several swarms of mafic dykes were injected into the already cold framework rocks, as is evident from dyke morphology. The dykes crosscut all predated structures, included turned blocks, and are therefore important reference points for subdivision of Neoarchean and Paleoproterozoic processes. The Svecofennian postdyke tectonic activity was accompanied by local shearing and boudinage of metabasic rocks, development of quartz and pegmatite veins along tension cracks, disharmonic folding, and discrete retrograde metamorphism up to amphibolite-facies conditions. The postdyke deformations did not exert a substantial effect on the previously formed regional structure.

  19. Early detection of eruptive dykes revealed by normalized difference vegetation index (NDVI) on Mt. Etna and Mt. Nyiragongo

    NASA Astrophysics Data System (ADS)

    Houlié, N.; Komorowski, J. C.; de Michele, M.; Kasereka, M.; Ciraba, H.

    2006-06-01

    Flank-fissure eruptions involve lateral injection and propagation of magma in a volcanic edifice along pre-existing fractures in the direction of the rift zones where magma intrusion and lava flow production are concentrated over time. Thus, the identification and mapping of active fractures and faults is a fundamental aspect of studies of active volcanic systems. However, gradual dyke wedge emplacement at depth in well-fractured zones on volcano flanks and in volcanic rift zones does not necessarily trigger large amplitude deformation signals susceptible to be recorded months or even years before the actual eruption. Here we show that active and potentially eruptive areas can be detected up to 2 yrs before the arrival to the surface of the final eruptive dyke and venting of lava flows by processing satellite images applying a normalized difference vegetation index (NDVI) algorithm. A posteriori analysis of satellite images indeed reveals that the surficial effects of dyke wedge injection and ascent on plant growth were apparent for Mt. Etna from 2000 to 2002 and for Mt. Nyiragongo in 2001, thus months to years before they erupted.

  20. Sediment dynamics over multiple time scales in Dyke Marsh Preserve (Potomac River, VA)

    NASA Astrophysics Data System (ADS)

    Palinkas, C. M.; Walters, D.

    2010-12-01

    Tidal freshwater marshes are critical components of fluvial and estuarine ecosystems, yet sediment dynamics within them have not received as much attention as their saltwater counterparts. This study examines sedimentation in Dyke Marsh Preserve, located on the Potomac River (VA), focusing on understanding the spatial variability present over multiple time scales. Bimonthly sediment data were collected using ceramic tiles, and seasonal- and decadal-scale sedimentation was determined via 7Be (half-life 53.3 days) and 210Pb (half-life 22.3 years), respectively. Results were also compared to SET data collected by the National Park Service since 2006. Preliminary data indicate that sites at lower elevations have higher sedimentation rates, likely related to their close proximity to the sediment source. Mass accumulation rates generally decreased with increasing time scale, such that the seasonal rates were greater than the SET-derived accretion rates, which were in turn greater than the decadal-scale rates. However, the bimonthly rates were the lowest observed, probably because the sampling period (May-October 2010) did not include the main depositional period of the year, which would be integrated by the other techniques.

  1. Evidence for dyke intrusion earthquake mechanisms near long valley caldera, California

    USGS Publications Warehouse

    Julian, B.R.

    1983-01-01

    A re-analysis of the magnitude 6 earthquakes that occurred near Long Valley caldera in eastern California on 25 and 27 May 1980, suggests that at least two of them, including the largest, were probably caused by fluid injection along nearly vertical surfaces and not by slip on faults. Several investigators 1,2 have reported difficulty in explaining both the long-period surface-wave amplitudes and phases and the locally recorded short-period body-wave first motions from these events, using conventional double-couple (shear fault) source models. They attributed this difficulty to: (1) complex sources, not representable by single-fault models; (2) artefacts of the analysis methods used; or (3) effects of wave propagation through hypothetical structures beneath the caldera. We show here that the data agree well with the predictions for a compensated linear-vector dipole (CLVD) equivalent-force system3 with its principal extensional axis horizontal and trending N 55-65?? E. Such a mechanism is what would be expected for fluid injection into dykes striking N 25-35?? W, which is the approximate strike of numerous normal faults in the area. ?? 1983 Nature Publishing Group.

  2. Late Variscan postcollisional extensional events in the Danubian domain (Romania): the Motru Dyke System

    NASA Astrophysics Data System (ADS)

    Campeanu, Mara; Balica, Constantin; Balintoni, Ioan; Stremtan, Cosmin

    2013-04-01

    An extensive system of dykes, known as the Motru Dyke Swarm (MDS), penetrates through the whole Danubian basement (Neoproterozoic high-grade metamorphic rocks, granitoid plutons of the same age in addition to a range of post-collisional Variscan granitoid plutons) in a presumed pre-Ordovician thermo-tectonic event [1]. Previously considered as illustrative for a sub-volcanic event occured in the early Palaeozoic (Cambrian - Ordovician), in a oceanic arc setting, based on the crosscutting field relationships with the Variscan post-collisional granitoid plutons combined with new geochemical and isotopic data, a new tectonic setting of emplacement is inferred. Even if the new zircon U/Pb ages on some components of MDS together with already published data reported by [2] does not confirm any Variscan or Late Variscan age, based on the same field relationships an upper Carboniferous age is supposed. The MDS belongs to a major complex of calc-alkaline dykes of Pan-African origin. The entire system penetrates most of the Lainici-Paius terrane components, at a relatively high crustal level, although it penetrate also Drăgan terrane components in some places. Its components consist of medium- to high-K sub-volcanic suites, composed of numerous sub-volcanic components of basic to felsic composition. These components compile a complete medium-K calc-alkaline to shshonitic differentiation series, ranging from basaltic andesites to rhyolites (46.59-68.79 wt% SiO2). Even if the trace elements trends share some similarities to those previously reported (e.g. [2]) generally they point to source heterogeneity. Some samples reveal low abundances in Nb, P and Ti, while others show relative enrichments in these elements in addition as well as in Th, Pb, Zr and Y, pointing to already enriched sources in these incompatible elements. The trace elements concentrations proportionally decrease with the increase of the SiO2 compositions. The mafic and intermediate rocks show enrichment in

  3. Characterization of the effect of dyke swarms on groundwater flow in a sedimentary coastal aquifer by combined geophysical and hydrogeological modelling

    NASA Astrophysics Data System (ADS)

    Burns, C.; Comte, J.; Gaffney, L.; Ofterdinger, U.; Young, M.

    2010-12-01

    In many parts of the North Atlantic region, the Permo-Triassic New Red Sandstone constitutes an important groundwater resource for drinking, agricultural and industrial water supply, thanks to relatively high transmissivity and storage properties. Such old sedimentary basins are often intruded by Paleogene volcanic dykes generally following the extensive deep fractures associated with the Mesozoic opening of the Atlantic Ocean. From local to regional scale, the effect of dyke swarms on the groundwater flow in these aquifers (i.e. as barriers, drains, or anisotropic bands) is poorly understood due to both the discrete nature of their occurrence and in many cases the existence of overlying deposits preventing their direct observation. To the Triassic Sherwood sandstone aquifer near Belfast, Northern Ireland, a combined modeling approach has been applied on a selected coastal site to evaluate the effect of dykes on groundwater flow. Geophysics was used to detect and map the dykes and natural seawater intrusion. First, information on the location, orientation and dipping of the dykes was provided by surface geomagnetic investigations and modeling. Second, electrical resistivity tomography (ERT) was applied to image both the dykes and the groundwater salinity. Inverse modeling of resistivity data is constrained using the dyke geometries from geomagnetic modeling. Thirdly, a variable-density groundwater flow model is applied, using established hydrogeological data, to simulate both the aquifer hydrodynamics and the saltwater distribution. Finally, several scenarios of permeability properties of the dykes are tested and the results compared to the seawater distribution provided by the geo-electrical models. Such a comparison allows discrimination of unrealistic scenarios, as well as both validating the groundwater numerical model and improving its calibration. Thus, it is shown that (1) at the local scale, the dykes act as low permeability zones, i.e. relative barriers

  4. Can we see the distal dyke communicate with the caldera? Examples of temporal correlation analysis using seismicity from the Bárðarbunga volcano

    NASA Astrophysics Data System (ADS)

    Jónsdóttir, Kristín; Jónasson, Kristján; Tumi Guðmundsson, Magnús; Hensch, Martin; Hooper, Andrew; Holohan, Eoghan; Sigmundsson, Freysteinn; Halldórsson, Sæmundur Ari; Vogfjörð, Kristín; Roberts, Matthew; Barsotti, Sara; Ófeigsson, Benedikt; Hjörleifsdóttir, Vala; Magnússon, Eyjólfur; Pálsson, Finnur; Parks, Michelle; Dumont, Stephanie; Einarsson, Páll; Guðmundsson, Gunnar

    2016-04-01

    The Bárðarbunga volcano is composed of a large oval caldera (7x11 km) and fissures extending tens of kilometers away from the caldera along the rift zone, which marks the divergent plate boundary across Iceland. On August 16th, 2014 an intense seismic swarm started below the Bárðarbunga caldera and in the two weeks that followed a dyke migrated some 47 km laterally in the uppermost 6-10 km of the crust along the rift. The dyke propagation terminated in lava fields just north of Vatnajökull glacier, where a major (1.5 km3) six months long eruption took place. Intense earthquake activity in the caldera started in the period August 21-24 with over 70 M5 earthquakes accompanying slow caldera collapse, as verified by various geodetic measurements. The subsidence is likely due to magma withdrawal from a reservoir at depth beneath the caldera. During a five months period, October-February, the seismic activity was separated by over 30 km in two clusters; one along the caldera rims (due to piecewise caldera subsidence) and the other at the far end of the dyke (as a result of small shear movements). Here we present statistical analysis comparing the temporal behaviour of seismicity recorded in the two clusters. By comparing the earthquake rate in the dyke in temporal bins before and after caldera subsidence earthquakes to the rate away from these bins (background rate), we show posing a statistical p-value test, that the number of dyke earthquakes was significantly higher (p <0.05) in the period 0-3 hours before a large earthquake (>M4.6) in the caldera. Increased dyke seismicity was also observed 0-3 hours following a large caldera earthquake. Elevated seismicity in the dyke before a large caldera earthquake may occur when a constriction in the dyke was reduced, followed by pressure drop in the chamber. Assuming that the large caldera earthquakes occurred when chamber pressure was lowest, the subsiding caldera piston may have caused temporary higher pressure in the

  5. Segmented Dyke Growth and Associated Seismicity at Bárðarbunga Volcanic System (Iceland) is Driven by Non-Linear Magma Pressure Diffusion

    NASA Astrophysics Data System (ADS)

    Langenbruch, C.

    2015-12-01

    In August 2014 segmented lateral dyke growth has been observed in a rifting event at Bardarbunga volcanic system, Iceland. The temporal evolution of the magma source and the physical nature of magma flow process during dyke propagation and arrest are unclear. The epidemic-type aftershock sequence model has been used to detect fluid signals in seismicity data. We use the earthquake catalog recorded during the rifting event to reconstruct the magma flow signal at the feeding source of the dyke. We find that the segmentation of dyke growth is caused by a pulsating nature of the magma flow source. We identify two main magma flow pulses, which initiate and propagate the two main segments of the dyke. During phases of dyke arrest magma flow pulses are low and cannot further propagate the dyke. We use the reconstructed magma flow signal to set up a numerical model of non-linear magma pressure diffusion. By using the magma pressure changes resulting from magma flow, we simulate the earthquake catalog caused by the reduction of the effective principal stress. We observe an excellent agreement between the spatio-temporal characteristics of the simulated earthquake catalog and recorded seismicity. Our results suggest that the process of magma pressure relaxation can be described as a non-linear diffusion process. Because the opening of the dyke creates significant new fracture volume, the permeability of the rock is strongly increasing and the diffusion process becomes highly non-linear. Our analysis is based on lessons learned from analysis of seismicity observed during hydraulic fracturing of hydrocarbon reservoirs. Despite large differences in scale, the underlying physical processes are comparable. Finally, we analyze the decay of seismic activity after start of the effusive fissure eruption near the end of the dyke. The magma flow strongly decreases and seismic activity decays according to Omori's law, which describes the decay of aftershock activity after tectonic

  6. The Nature of Feldspar Clouding and Its Paleomagnetic Significance With Reference To The 2.45 Ga Matachewan Dyke Swarm, Canada

    NASA Astrophysics Data System (ADS)

    Halls, Henry C.; Zhang, Baoxing; Garland, Mary

    Clouding in calcic plagioclase is a common occurrence in Precambrian diabase dyke swarms worldwide, particularly those of Paleoproterozoic age. The occurrence of this clouding in 2.45 Ga Matachewan dykes within uplifted blocks of the Kapuskasing Zone (KZ) in Canada, and not in dykes of the same swarm at shallower crustal levels in surrounding terranes, suggests that the clouding is produced as a re- equilibration of the felspar in response to declining temperatures but in the presence of pressures appropriate to mid - to lower- crustal levels. We have made the following observations on feldspar separates extracted from the dykes: (1) Curie Balance, and low temperature SIRM acquisition studies show Curie temperarures of 580° C and a Verwey transition at 110-120K appropriate for Ti-poor magnetite; (2) Saturation magnetization is proportional to clouding intensity as determined from image analysis techniques; (3) Hysteresis and SEM studies indicate that the particles are small, typically about 1 micron (PSD) in size; (4) A baked contact test on cloudy feldspar dykes within the KZ is negative, but positive for dykes outside the KZ; (5) Magnetite in cloudy feldspars carries a high coercivity N component of magnetization which increases with clouding intensity, whereas dykes outside the KZ mostly carry an older R remanence; (6) Since sets of R dykes become N along strike on entering the KZ, the magnetization carried by cloudy feldspars is secondary; (7) The presence of R host rocks adjacent to an N cloudy dyke and the occasional survival of lower Hc and lower Tub R components in N cloudy dykes within the KZ suggests that the N magnetization of the feldspar magnetite is a CRM; (8) SEM shows that feldspars of different clouding intensity (from image analysis) have a near constant atomic percentage of Fe, so that the degree of clouding is determined in part by the concentration of magnetite rather than by total Fe and indicates that from 30-90% of the total Fe is used in

  7. Proterozoic Diabase Dyke Swarms of Northern Ontario: Paleomagnetic Indicators of Broad-Scale Crustal Deformation of the Archean Superior Province

    NASA Astrophysics Data System (ADS)

    Halls, H. C.

    2004-05-01

    Several Proterozoic dyke swarms, all with precise U-Pb ages, (Matachewan, Senneterre, Biscotasing, Marathon and Fort Frances) occur over an area of the southern Superior Province covering more than 300,000 square kilometres. Cutting across this region is the Kapuskasing Zone, a 500 km-long fault zone along which dextral transpression at about 1.9 to 2.0 Ga has produced crustal uplift locally in excess of 20 km and lateral fault displacements of up to 70 km (Percival and West, 1994). The 2446-2473 Ma Matachewan swarm has been a subject for study throughout the last 40 years of Canadian paleomagnetism. However only in the last 20 years has the true size of the swarm been realised (Ernst and Halls, 1984; Halls et al., 1994), and the discovery made that regional variations in the direction of primary magnetization in the dykes are intimately related to the Kapuskasing Zone (KZ). The swarm is now known to span a single reversal of the Earth's magnetic field. The younger N polarity epoch, although barely recorded in the dying stages of the intrusive episode, is well preserved in dykes within uplifted crust inside the KZ. Here fine-grained magnetite, exsolved from dyke feldspars due to slow cooling of the swarm at depth, acquired a remanence of probable thermo-chemical origin prior to or during crustal uplift (Halls and Palmer, 1990; Halls et al., 1994; Halls and Zhang, 2003). The inference is that dykes intruded during the older R polarity epoch carry a near surface primary R magnetization but have been remagnetized to N at depth. Paleomagnetic data from that part of the swarm outside the KZ are therefore dominated by the older R polarity magnetization. They show that the western half of the shield has rotated counter-clockwise about 10 to 20 degrees relative to the eastern half across the KZ (Bates and Halls, 1991; Halls and Stott, 2003). This rotation is also seen in paleomagnetic data from the 2170 Ma Biscotasing swarm, which is now known to occur on both sides of the

  8. U-Pb ages and geochemistry of mafic dyke swarms from the Uauá Block, São Francisco Craton, Brazil: LIPs remnants relevant for Late Archaean break-up of a supercraton

    NASA Astrophysics Data System (ADS)

    Oliveira, E. P.; Silveira, E. M.; Söderlund, U.; Ernst, R. E.

    2013-08-01

    The São Francisco Craton (SFC) is an Archaean craton that hosts a significant number of mafic intrusions. Previous attempts to date the igneous emplacement of these rocks are limited to a few dates of poor precision. Here, two dyke swarms from the Uauá Block in the northeastern portion of the craton were dated using U-Pb on baddeleyite (ID-TIMS) and zircon (SIMS). The older dyke swarm trends mainly N-S to NW-SE (but also NE) and comprises norite dykes, whereas the younger dykes are tholeiite and trend NE-SW. The ages of 2726.2 ± 3.2 and 2623.8 ± 7.0 Ma date dykes of noritic and tholeiitic compositions, respectively. The older age matches the ages of several Archaean-Large Igneous Provinces (tholeiitic-komatiite greenstone belts and continental flood basalts) worldwide and represents part of a feeder system, but the younger age is similar to Andean style continental margin magmatism in the São Francisco and Zimbabwe cratons. The two dyke swarms are tholeiitic in composition but the noritic dykes are more enriched in both compatible and incompatible elements and have higher (La/Yb)N ratios than the tholeiite dykes. The norite dykes are interpreted as low degrees of melting from enriched refractory mantle sources, whereas the tholeiite dykes represent high degrees of partial melting of more depleted mantle sources; the two mafic dyke swarms may be related to each other by progressive extension of the continental lithosphere. It is suggested that the Uauá Block with its dyke swarms is a small piece of Archaean crust dispersed after the break-up of a major Archaean supercraton.

  9. The Deccan tholeiite lavas and dykes of Ghatkopar-Powai area, Mumbai, Panvel flexure zone: Geochemistry, stratigraphic status, and tectonic significance

    NASA Astrophysics Data System (ADS)

    Sheth, Hetu C.; Zellmer, Georg F.; Demonterova, Elena I.; Ivanov, Alexei V.; Kumar, Rohit; Patel, Rakesh Kumar

    2014-04-01

    Mumbai City, situated on the western Indian coast, is well known for exposures of late-stage Deccan pillow basalts and spilites, pyroclastic rocks, rhyolite lavas, and trachyte intrusions. These rock units, and a little-studied sequence of tholeiitic flows and dykes in the eastern part of Mumbai City, constitute the west-dipping limb of a regional tectonic structure called the Panvel flexure. Here we present field, petrographic, major and trace element and Sr-Nd isotopic data on these tholeiitic flows and dykes, best exposed in the Ghatkopar-Powai area. The flows closely resemble the Mahabaleshwar Formation of the thick Western Ghats sequence to the east, in Sr-Nd isotopic ratios and multielement patterns, but have other geochemical characteristics (e.g., incompatible trace element ratios) unlike the Mahabaleshwar or any other Formation. The flows may have originated from a nearby eruptive center, possibly offshore of Mumbai. Two dykes resemble the Ambenali Formation of the Western Ghats in all geochemical characteristics, though they may not represent feeders of the Ambenali Formation lavas. Most dykes are distinct from any of the Western Ghats stratigraphic units. Some show partial (e.g., Sr-Nd isotopic) similarities to the Mahabaleshwar Formation, and these include several dykes with unusual, concave-downward REE patterns suggesting residual amphibole and thus a lithospheric source. The flows and dykes are inferred to have undergone little or no contamination, by lower continental crust. Most dykes are almost vertical, suggesting emplacement after the formation of the Panvel flexure, and indicate considerable east-west lithospheric extension during this late but magmatically vigorous stage of Deccan volcanism.

  10. Teleseismic earthquake swarms at ultraslow spreading ridges: indicator for dyke intrusions?

    NASA Astrophysics Data System (ADS)

    Schlindwein, V.

    2012-07-01

    Earthquakes at mid-ocean ridges reflect the active magmatic and tectonic processes that form new oceanic crust. Studies of large earthquakes observed on land and smaller earthquakes observed locally or regionally by ocean bottom seismometers or autonomous underwater hydrophones have greatly contributed to our understanding of the structure and active spreading processes at the mid-ocean ridges of the Atlantic and Pacific Ocean opening with velocities in excess of 25 mm yr-1. At spreading rates below 20 mm yr-1 full rate, the appearance and the accretion processes of mid-ocean ridges undergo fundamental changes as the melt supply is drastically reduced. The active spreading processes at these so-called ultraslow spreading ridges are still poorly known, as the main representatives, the Arctic Ridge System and the Southwest Indian Ridge, are poorly accessible and neither autonomous underwater hydrophone nor ocean bottom seismometer records of local seismicity are available. In an attempt to compare on a large scale the accretion style of ultraslow spreading ridge sections, I analyse the teleseismically recorded seismicity in 11 sections of the Arctic Ridge System and the Southwest Indian Ridge spanning altogether 7200 km. Epicentres located within 30-35 km of the rift axis were extracted from the catalogue of the International Seismological Centre for a time period of 35 yr. On the basis of a single-link cluster analysis, I identified 27 swarms with eight or more events. These swarms occur almost exclusively at centres of focussed magmatism suggesting that the swarms are probably initiated by magmatism. Normal faults along several tens of kilometres surrounding the volcanic centres react in large earthquakes (M > 5) to dyke emplacement. The routine generation of large earthquakes in the cold, brittle lithosphere of ultraslow spreading ridges makes the teleseismic record a valuable means to study ultraslow accretion processes and to provide a global framework for the

  11. The Karoo triple junction questioned : Evidence from 40Ar/39Ar Jurassic and Proterozoïc ages and geochemistry of the Okavango dyke swarm (Botswana).

    NASA Astrophysics Data System (ADS)

    Jourdan, F.; Féraud, G.; Bertrand, H.; Kampunzu, A. B.; Tshoso, G.; Le Gall, B.; Tiercelin, J. J.

    2003-04-01

    The lower Jurassic Karoo-Ferrar magmatism represents one of the most important Phanerozoic continental flood basalt (CFB) provinces. Karoo CFB is dominated by tholeiitic traps and apparently radiating giant dyke swarms covering altogether ca 3x106 km2. This study focuses on the giant N110° oriented Okavango dyke swarm (ODS) stretching over a distance of 1500 km through Botswana. This dyke swarm represents the main arm of the so-called Karoo triple junction which is generally considered as a key marker linking the Karoo magmatism to a starting mantle plume impact (Campbell and Griffiths, 1990). ODS dolerites yield twelve reliable plagioclase 40Ar/39Ar plateau (and mini-plateau) ages ranging from 178.3 +-1.1 (2 sigma) to 179.3 +-1.2 Ma (Le Gall et al, 2002 and unpublished data). The distribution of the ages along a narrow gaussian curve suggests a short period of magmatic activity centered around 178.9 Ma. In addition, small clusters of plagioclase separated from twenty-five other dykes and measured by total fusion, gave either Karoo or Proterozoïc ages. The Proterozoïc rocks range from 758.2 +-6.6 Ma and 1223.8 +-10.0 Ma (integrated ages) and, although petrographically indistinguishable in some cases, they display clear geochemical differences (e.g. TiO2<2%, Ti/Y<400) compared to the Karoo high-Ti ODS (TiO2>2%, Ti/Y>400). Geochemical data combined with available Ar/Ar dates allowed us to identify the two groups within a total set of seventy-eight dykes investigated: about 15 % of the bulk ODS dykes were emplaced during the Proterozoïc and, thus, the Jurassic Karoo dykes were emplaced along reactivated Proterozoïc structures. The validity of the Karoo triple junction-plume model, should therefore be revisited. Although available data on Proterozoïc dykes along the ODS are not precise enough to assess their exact emplacement age, they indicate that most of the Proterozoïc dykes were emplaced between 900 and 1100 Ma. This age range is the same as dating commonly

  12. Large-scale liquid immiscibility and fractional crystallization in the 1780 Ma Taihang dyke swarm: Implications for genesis of the bimodal Xiong'er volcanic province

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Wang, Xinping; Lai, Yong; Wang, Chong; Windley, Brian F.

    2015-11-01

    Immiscibility is a potential mechanism for the formation of high-Fe-Ti-P rocks; however, whether large-scale segregation and eruption of high-Si lavas can occur in nature has yet to be proven. In this study, we investigate the possibility of immiscibility between the cogenetic 1780 Ma high-Fe-Ti-P-bearing Taihang dykes and the 'bimodal' Xiong'er volcanics in North China. The compositions of silicate melt inclusions in plagioclase megacrysts of the dykes provide a new approach to obtain the primary liquid. Mineral and bulk-rock compositions reveal that large compositional variations in the dykes are the result of plagioclase- and clinopyroxene-dominated fractional crystallization and of density-driven mineral sorting, which together caused the liquids to be poor in Ca-Al but rich in Fe-Ti-P-K, and thus chemically immiscible. Conjugate interstitial granophyric and ilmenite-rich intergrowths and reactive microstructures especially olivine coronas in the dykes, and Si-/Fe-Ti-rich globules in the volcanics, provide petrographic evidence for the presence of two coeval, coexisting liquids in equilibrium separated by a miscibility gap, and thus for immiscibility and segregation/migration. The fractional crystallization and subsequent segregation were responsible for the compositional diversity of the Taihang dykes and also of the 'bimodal' Xiong'er volcanics. Accordingly, the dacite and rhyolite lavas are potentially the high-Si counterparts of the high-Ti dykes, and the basalt and andesite lavas are the erupted equivalents of the relatively low-Ti dykes. It is likely that the sustained plagioclase- and clinopyroxene-dominated fractional crystallization, and the enhanced fO2 were responsible for the immiscibility. The segregation probably took place during the ascent of the liquid in the pumping system (feeder dykes). This likely represents one natural example of crust-scale immiscibility from which many high-Ti dykes and silicic lavas (~ 1/3 volume of the Xiong

  13. Zr-Y-Nb-REE mineralization associated with microgranite and basic dykes at EL Sela shear zone, South Eastern Desert, Egypt.

    PubMed

    Shahin, Hassan Abd El-Razek Aly

    2014-01-01

    El Sela shear zone occurs in the younger granite rock of Gabal El Sela area, south Eastern Desert, Egypt near the Sudan Frontier. It comprises lines-arranged intrusions trending ENE-WSW and extend for about 1.5 km in length and reach up to 40 meters in width. These lines-arranged intrusions include multi-phase quartz veins, altered microgranite and altered basic dykes. These dykes hosting or acting as a source for uranium, rare metals (Zr, Y, Nb and Ga) and light rare earths (La, Ce, Sm and Nd) mineralizations. They show highly alteration, uranium enrichment and a strong enrichment in some rare metals and light rare earths contents (Zr = 644, Y = 133, Nb = 136, Ga =184, La = 50.19, Ce = 105.47, Sm = 24.81, Nd = 78.91 ppm and and ∑ LREEs = 259.38.). The chondrite normalised rare earth elements trends indicate strongly fractionated rare earth elements pattern with significant enriched of LREE according to HREE in both altered microgranite and altered basic dykes. Field radiometric measurements of the studied altered microgranite dyke revealed that eU reach up to 359 ppm with an average 78 ppm, while in the altered basic dyke reach up to 1625 ppm with an average 144 ppm. PMID:25332873

  14. Nature of mantle source contributions and the role of contamination and in situ crystallisation in the petrogenesis of Proterozoic mafic dykes and flood basalts Labrador

    NASA Astrophysics Data System (ADS)

    Cadman, A. C.; Tarney, J.; Baragar, W. R. A.

    1995-12-01

    Proterozoic tholeiitic dyke swarms share many compositional features with, and pose similar petrogenetic problems to, Phanerozoic continental flood basalts, but there are few extrusive equivalents of such swarms. The Mesoproterozoic (1.27 Ga) Harp dyke swarm in Labrador is one where possible extrusive equivalents exist in the Seal Lake group, but are slightly displaced in space and time, and can probably be related by models of progressive crustal extension. Here we try to evaluate the roles of crystal differentiation, in situ crystallisation, crustal assimilation and the relative contributions of asthenosphere- and lithosphere-derived melts in the petrogenesis of the mafic magmas. Modelling of the major and trace element variations both within individual dykes and between dykes, and within the lava sequence, does not suggest an important role for continental crust involvement. While in situ crystallisation processes could account for some of the compositional variations, the most successful models invoke mixing or contamination of asthenospheric magmas with/by veined material in the lower lithosphere / upper asthenosphere which carries the ‘continental’ characteristics. The results imply an important role for hydrous phases such as phlogopite and hornblende in the sub-lithosphere mantle. Much of the low-MgO character of mafic dykes may result from significant removal of mafic phases during in situ crystallisation within the lithosphere.

  15. Calc-alkaline mafic rocks of the Black Dyke Formation: Remnants of the final activity of a submerged Permian volcano

    SciTech Connect

    Blein, O.; Lapierre, H.; Pecher, A. ); Schweickert, R.A. . Dept. of Geological Science)

    1993-04-01

    The Permian Black Dyke Fm., which occurs as large tectonic slices within the Luning allochthon in the Excelsior Mountains, NV, forms an E-W trending anticline at Black Dyke Mountain. The 800-m thick stratigraphic succession consists of volcanic and pyroclastic rocks overlain conformably by volcaniclastic sediments. Along the northern limb of the anticline, the rocks consist of mafic porphyritic lavas, breccias, and graded and ungraded pyroclastic beds. The sedimentary unit consists of thick volcaniclastic turbidites overlain by conglomerates, sandstones, and mudstones. Along the southern limb of the anticline, the sequence is replaced by reworked breccia, tuffs, and sandstones. Mafic plutonic rocks occur as xenoliths in the lavas and breccias, and as coeval plugs intruding the section. Gabbros show cumulate or porphyritic textures and are composed of amph, cpx, and zoned plag. Their Ti/V (14.5--15) and Nb/Y (0.25--0.3) ratios fall in the range commonly found in calc-alkaline rocks. Diorite porphyry shows high Al[sub 2]O[sub 3], ZrO[sub 2], and REE abundances indicating that this rock is more fractionated. Basalts and andesites are plag-cpx-opx phyric. They often include glomeroporphyritic clots of cpx with amph coronas. Some rocks exhibit fluidal textures. Both volcanic and plutonic rocks show homogeneous geochemical features and similar crystallization sequences: Fe-Ti oxides---->plag---->opx + cpx----> brown zoned hbl, suggesting that they are cogenetic. Thus, the lower part of the Black Dyke Fm. likely represents the final products formed in a calc-alkaline magma chamber because pyroclastic rocks prevail over lava flows and abundant early crystal cumulates occur as plugs or as inclusions in the lavas and breccias.

  16. Valles Marineris as a Cryokarstic Structure Formed by a Giant Dyke System: Support From New Analogue Experiments

    NASA Astrophysics Data System (ADS)

    Ozeren, M. S.; Sengor, A. M. C.; Acar, D.; Ülgen, S. C.; Onsel, I. E.

    2014-12-01

    Valles Marineris is the most significant near-linear depression on Mars. It is some 4000 km long, up to about 200 km wide and some 7 km deep. Although its margins look parallel at first sight, the entire structure has a long spindle shape with significant enlargement in its middle (Melas Chasma) caused by cuspate slope retreat mechanisms. Farther to its north is Hebes Chasma which is an entirely closed depression with a more pronounced spindle shape. Tithonium Chasma is a parallel, but much narrower depression to its northeast. All these chasmae have axes parallel with one another and such structures occur nowhere else on Mars. A scabland surface exists to the east of the Valles Marineris and the causative water mass seems to have issued from it. The great resemblance of these chasmae on mars to poljes in the karstic regions on earth have led us to assume that they owed their existence to dissolution of rock layers underlying them. We assumed that the dissolving layer consisted of water ice forming substantial layers, in fact entirely frozen seas of several km depth. We have simulated this geometry by using bentonite and flour layers (in different experiments) overlying layers of ice in which a resistant coil was used to simulate a dyke. We used different thicknesses of bentonite and flour overlying ice layers again of various thicknesses. The flour seems to simulate the Martian crust better because on Mars, g is only about 3/8ths of its value on Earth, so (for equal crustal density) the depth to which the cohesion term C remains important in the Mohr-Coulomb shear failure criterion is about 8/3 times greater. As examples we show two of those experiments in which both the rock analogue and ice layers were of 1.5 cm. thick. Perfect analogues of the Valles Marineris formed above the dyke analogue thermal source complete with the near-linear structure, overall flat spindle shape, cuspate margins, a central ridge, parallel side faults, parallel depressions resembling

  17. Ford Van Dyke: Compressed Air Management Program Leads to Improvements that Reduce Energy Consumption at an Automotive Transmission Plant

    SciTech Connect

    Not Available

    2005-05-01

    Staff at the Ford Van Dyke Transmission Plant in Sterling Heights, Michigan, have increased the efficiency of the plant's compressed air system to enhance its performance while saving energy and improving production. After plant staff identified opportunities for system improvements, a qualified instructor from a U.S. Department of Energy (DOE) Allied Partner, Scales Air Compressor Corporation, helped to clarify several of them. The resulting improvement measures are yielding energy savings for compressed air of more than 1 million kWh; energy and maintenance cost savings total $165,000. The total cost of planned upgrades and other measures was $336,000, for a 2-year simple payback.

  18. Interview with a quality leader--Karen Davis, executive director of The Commonwealth Fund. Interview by Lecia A. Albright.

    PubMed

    Davis, Karen

    2009-01-01

    Karen Davis is president of The Commonwealth Fund, a national philanthropy engaged in independent research on health and social policy issues. Dr. Davis is a nationally recognized economist, with a distinguished career in public policy and research. Before joining the Fund, she served as chairman of the Department of Health Policy and Management at The Johns Hopkins School of Public Health, where she also held an appointment as professor of economics. She served as deputy assistant secretary for health policy in the Department of Health and Human Services from 1977 to 1980, and was the first woman to head a U.S. Public Health Service agency. Before her government career, Ms. Davis was a senior fellow at the Brookings Institution in Washington, DC; a visiting lecturer at Harvard University; and an assistant professor of economics at Rice University. A native of Oklahoma, she received her PhD in economics from Rice University, which recognized her achievements with a Distinguished Alumna Award in 1991. Ms. Davis is the recipient of the 2000 Baxter-Allegiance Foundation Prize for Health Services Research. In the spring of 2001, Ms. Davis received an honorary doctorate in human letters from John Hopkins University. In 2006, she was selected for the Academy Health Distinguished Investigator Award for significant and lasting contributions to the field of health services research in addition to the Picker Award for Excellence in the Advancement of Patient Centered Care. Ms. Davis has published a number of significant books, monographs, and articles on health and social policy issues, including the landmark books HealthCare Cost Containment, Medicare Policy, National Health Insurance: Benefits, Costs, and Consequences, and Health and the War on Poverty. She serves on the Board of Visitors of Columbia University, School of Nursing, and is on the Board of Directors of the Geisinger Health System. She was elected to the Institute of Medicine (IOM) in 1975; has served two

  19. Sentinel-1 TOPS interferometry for geophysical applications: Dyke intrusion imaged during 2014 Pico do Fogo eruption

    NASA Astrophysics Data System (ADS)

    Gonzalez, Pablo J.; Marinkovic, Petar; Samsonov, Sergey; Hooper, Andrew; Larsen, Yngvar; Wright, Tim

    2015-04-01

    apply Sentinel-1 TOPS-InSAR to illuminate the deformation accompanying a recent volcanic eruption at Pico do Fogo volcano, Fogo (Cape Verde). The detected deformation is consistent with a shallow near-vertical dyke intrusion, which fed the fissure eruption. The modelling of the deformation interferograms do not seem affected largely by the variable LoS vector, in this case. The presented results prove the potential of Terrain observation by progressive scans (TOPS) interferometry for geophysical applications, in particular using ESA Sentinel-1 mission.

  20. Geochronology and geochemistry of a dyke host rock association and implications for the formation of the Bavarian Pfahl shear zone, Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Siebel, Wolfgang; Blaha, Ulrich; Chen, Fukun; Rohrmüller, Johann

    2005-02-01

    To place constraints on the formation and deformation history of the major Variscan shear zone in the Bavarian Forest, Bavarian Pfahl zone, SW Bohemian Massif, granitic dykes and their feldspar-phyric massive host rock (so-called “palite”), zircons were dated by the U Pb isotope dilution and Pb-evaporation methods. The dated samples comprise two host rocks and four dykes from a K-rich calc-alkaline complex adjoining the SW part of the Bavarian Pfahl shear zone. The palites, which appear to be the oldest magmatic rocks emplaced in the shear zone, yield ages of 334±3, 334.5±1.1 Ma (average 207Pb/206Pb-evaporation zircon ages) and 327 342 Ma (range of U/Pb zircon ages) suggesting a Lower Carboniferous age for the initiation of the Pfahl zone. Absence of inherited older cores in all investigated zircons indicates that incorporation of crustal zircon material has played virtually no role or that the melting temperature was very high. Determination of the dyke emplacement age is complicated by partial Pb-loss in most of the fractions analysed. This Pb-loss can be ascribed to higher U content of the dyke zircons compared to those from host rock. Upper discordia intercept ages of the different dykes range from 322±5 to 331±9 Ma. The dykes are pre- to synkinematic with respect to penetrative regional mylonitisation along the Pfahl zone, and the upper intercept ages provide a maximum age for this tectonic event.

  1. Age and geochemistry of mantle peridotites and diorite dykes from the Baldissero body: Insights into the Paleozoic-Mesozoic evolution of the Southern Alps

    NASA Astrophysics Data System (ADS)

    Mazzucchelli, Maurizio; Zanetti, Alberto; Rivalenti, Giorgio; Vannucci, Riccardo; Correia, Ciro Teixeira; Tassinari, Colombo Celso Gaeta

    2010-10-01

    Trace element and isotopic data obtained for mantle spinel lherzolites and diorite dykes from the Baldissero massif (Ivrea-Verbano Zone, Western Italy) provide new, valuable constraints on the petrologic and geodynamic evolution of the Southern Alps in Paleozoic to Mesozoic times. Whole rock and mineral chemistry indicates that Baldissero lherzolites can be regarded as refractory mantle residues following limited melt extraction. In particular, the Light Rare Earth Elements (LREE)-depleted and fractionated compositions of whole rock and clinopyroxene closely match modelling results for refractory residues after low degrees (~ 4-5%) of near-fractional melting of depleted mantle, possibly under garnet-facies conditions. Following this, the peridotite sequence experienced subsolidus re-equilibration at lithospheric spinel-facies conditions and intrusion of several generations of dykes. However, lherzolites far from dykes show very modest metasomatic changes, as evidenced by the crystallisation of accessory titanian pargasite and the occurrence of very slight enrichments in highly incompatible trace elements (e.g. Nb). The Re-Os data for lherzolites far from the dykes yield a 376 Ma (Upper Devonian) model age that is considered to record a partial melting event related to the Variscan orogenic cycle s.l. Dioritic dykes cutting the mantle sequence have whole rock, clinopyroxene and plagioclase characterised by high radiogenic Nd and low radiogenic Sr, which point to a depleted to slightly enriched mantle source. Whole rock and mafic phases of diorites have high Mg# values that positively correlate with the incompatible trace element concentrations. The peridotite at the dyke contact is enriched in orthopyroxene, iron and incompatible trace elements with respect to the lherzolites far from dykes. Numerical simulations indicate that the geochemical characteristics of the diorites can be explained by flow of a hydrous, silica-saturated melt accompanied by reaction with the

  2. Dykes and structures of the NE rift of Tenerife, Canary Islands: a record of stabilisation and destabilisation of ocean island rift zones

    NASA Astrophysics Data System (ADS)

    Delcamp, A.; Troll, V. R.; van Wyk de Vries, B.; Carracedo, J. C.; Petronis, M. S.; Pérez-Torrado, F. J.; Deegan, F. M.

    2012-07-01

    Many oceanic island rift zones are associated with lateral sector collapses, and several models have been proposed to explain this link. The North-East Rift Zone (NERZ) of Tenerife Island, Spain offers an opportunity to explore this relationship, as three successive collapses are located on both sides of the rift. We have carried out a systematic and detailed mapping campaign on the rift zone, including analysis of about 400 dykes. We recorded dyke morphology, thickness, composition, internal textural features and orientation to provide a catalogue of the characteristics of rift zone dykes. Dykes were intruded along the rift, but also radiate from several nodes along the rift and form en échelon sets along the walls of collapse scars. A striking characteristic of the dykes along the collapse scars is that they dip away from rift or embayment axes and are oblique to the collapse walls. This dyke pattern is consistent with the lateral spreading of the sectors long before the collapse events. The slump sides would create the necessary strike-slip movement to promote en échelon dyke patterns. The spreading flank would probably involve a basal decollement. Lateral flank spreading could have been generated by the intense intrusive activity along the rift but sectorial spreading in turn focused intrusive activity and allowed the development of deep intra-volcanic intrusive complexes. With continued magma supply, spreading caused temporary stabilisation of the rift by reducing slopes and relaxing stress. However, as magmatic intrusion persisted, a critical point was reached, beyond which further intrusion led to large-scale flank failure and sector collapse. During the early stages of growth, the rift could have been influenced by regional stress/strain fields and by pre-existing oceanic structures, but its later and mature development probably depended largely on the local volcanic and magmatic stress/strain fields that are effectively controlled by the rift zone growth

  3. Late Palaeoproterozoic mafic dyking in the Ukrainian Shield of Volgo-Sarmatia caused by rotation during the assembly of supercontinent Columbia (Nuna)

    NASA Astrophysics Data System (ADS)

    Bogdanova, Svetlana V.; Gintov, Oleg B.; Kurlovich, Dzmitry M.; Lubnina, Nataliya V.; Nilsson, Mimmi K. M.; Orlyuk, Mykhailo I.; Pashkevich, Inna K.; Shumlyanskyy, Leonid V.; Starostenko, Vitaly I.

    2013-08-01

    The Ukrainian Shield comprises the exposed crust of the large Palaeoproterozoic protocraton Volgo-Sarmatia, which together with the Fennoscandian crustal segment constitutes the East European Craton ("Baltica"). Geological and geophysical data indicate that 1.80 to 1.75 Ga mafic dykes related to anorthosite-mangerite-charnockite-granite (AMCG) plutons are widespread within the Ukrainian Shield. We examined their ages, distribution patterns, orientations and compositions in three different crustal blocks (Volyn, Ingul and Azov), and found close spatial relationships with major strike-slip fault systems developed during two phases of extension. The early, 1.80-1.77 Ga, generation of mafic dykes mostly follows NW (330 ± 20°) and more rarely N-S- or E-W-trending faults corresponding to major NE-SW extension (the Submoshorino phase). These dykes contain olivine dolerites, picrites, camptonites, lamprophyres, kimberlites and other rocks belonging to tholeiitic and subalkaline jotunitic series. The compositions of these dykes differ between the host blocks, but all feature upper mantle geochemical signatures such as high contents of Ni and Cr, and positive values of εNd(1800) up to + 2.8. High degrees of REE fractionation indicate deep levels of mantle melting, which is particularly characteristic of the Ingul block as marked by the most extensive and dense mafic dyke swarms. The later, 1.76-1.75 Ga, dyke swarms occur close to the most voluminous AMCG suites of similar age and were emplaced during the second (Korsun) phase of faulting when all the older strike-slip fault zones were reactivated and partly transformed to tensional faults by E-W extension. These dyke swarms mainly trend 030 ± 20°. They are jotunitic and their isotopic signatures indicate a greater participation of crustal sources in the parent melts. The overall transtensional tectonic setting of the mafic dyking associated with the AMCG magmatism in Volgo-Sarmatia was created by convergent tectonics

  4. Fluid Inclusion Study of Quartz Xenocrysts in Mafic Dykes from Kawant Area, Chhota Udaipur District, Gujarat, India

    NASA Astrophysics Data System (ADS)

    Randive, Kirtikumar; Hurai, Vratislav

    2015-09-01

    Unusual mafic dykes occur in the proximity of the Ambadongar Carbonatite Complex, Lower Narmada Valley, Gujarat, India. The dykes contain dense population of quartz xenocrysts within the basaltic matrix metasomatised by carbonate-rich fluids. Plagioclase feldspars, relict pyroxenes, chlorite, barite, rutile, magnetite, Fe-Ti oxides and glass were identified in the basaltic matrix. Quartz xenocrysts occur in various shapes and sizes and form an intricate growth pattern with carbonates. The xenocrysts are fractured and contain several types of primary and secondary, single phase and two-phase fluid inclusions. The two-phase inclusions are dominated by aqueous liquid, whereas the monophase inclusions are composed of carbonic gas and the aqueous inclusions homogenize to liquid between 226°C and 361°C. Majority of the inclusions are secondary in origin and are therefore unrelated to the crystallization of quartz. Moreover, the inclusions have mixed carbonic-aqueous compositions that inhibit their direct correlation with the crustal or mantle fluids. The composition of dilute CO2-rich fluids observed in the quartz xenocrysts appear similar to those exsolved during the final stages of evolution of the Amba Dongar carbonatites. However, the carbonates are devoid of fluid inclusions and therefore their genetic relation with the quartz xenocrysts cannot be established.

  5. A New Occurrence of Alkaline Magmatism on the Kola Peninsula: An Agpaitic Dyke in the Kandalaksha Region.

    NASA Astrophysics Data System (ADS)

    Akimenko, Mariya; Kogarko, Lia; Sorokhtina, Natalia; Kononkova, Natalia; Mamontov, Vladimir

    2015-04-01

    A new occurrence of alkaline dyke magmatism was discovered in 2010 during the geological works performed by the Murmansk Geological Prospecting Expedition in the "Mokhnatye Roga" area located 55 km to the southeast of the Kovdor massif (67°15' N, 31°30' E). The "Mokhnatye Roga" area is located in the Ensk segment of the northwestern part of the Belomorian mobile belt. We performed a complete petrological and geochemical description of the sections in Holes 19 and 24, which reveal one of the largest dykes in the area. The dyke, with a length of ≈4 km and a width of ≈160 m, has an eastern orientation with steep dipping (60°-90°) to the north. The thickness of Quaternary deposits ranges from 0.8 to 4.0 m; alkaline rocks occur in the range of 4.0-93.9 m being followed by host amphibole-biotite gneiss with interbeds of plagioamphibolite (AR2 mt) along the section. Among the major minerals of the dyke are the minerals of the lamprophyllite group (20-25 vol %), aegirine-augite (10-15 vol %), enigmatite (10-15 vol %), nepheline (10-15 vol %), orthoclase (15-20 vol %), alkaline amphibole (5-10 vol %), and astrophyllite (up to 5 vol %). The minor minerals are represented by shcherbakovite, sodalite, natrolite, barite, Mn carbonate, ilmenite, rutile, sphalerite, and goethite. The texture of the rock is porphyric: the groundmass is composed of finegranular nepheline and orthoclase, which are observed as individual large euhedral crystals as well. In addition, large phenocrysts are represented by the minerals of the lamprophyllite, enigmatite, pyroxene, and alkaline amphibole groups. Based on the generally accepted classifications [1], the studied agpaitic rock may be related to nepheline syenite; according to the mineral and chemical compositions, it is close to syenite of the Niva massif [2] located 35 km to the northeast from the "Mokhnatye Roga" area. Agpaitic syenite of the "Mokhnatye Roga" area is extremely enriched in dispersed and rare lithophile elements. The

  6. Petrographical and geochemical characteristics of the sheeted dyke-gabbro transition zone in ODP/IODP Hole 1256D

    NASA Astrophysics Data System (ADS)

    Python, M.; France, L.; Abily, B.; Abe, N.; Alt, J. C.; Godard, M. M.; Ildefonse, B.; Koepke, J. H.; Kurtz, M. D.; Oizumi, R.; Payot, B. D.

    2012-04-01

    During IODP Expedition 335, high grade granoblastic hornfels were extensively recovered as drilling cuttings at the gabbro-sheeted dyke transition zone of ODP Hole 1256D (East Pacific Rise, 6°44.163'N, 91°56.061'W). This lithology probably results from high-temperature metamorphism of previously hydrothermally altered diabases and/or basalts; the heat source likely stems from the melt lens located at the top of the magmatic chambers imaged along present-day fast-spreading ridges. This lithology, associated with gabbroic bodies, characterises the transition zone between the sheeted dyke complex and the uppermost gabbroic section, and represents the interface between magmatic and hydrothermal convecting systems in an oceanic crust formed at fast-spreading ridges. In this study, 14 samples from the junk basket (cuttings) and 2 samples from cores obtained during Expedition 335 were observed and analysed. The petrological and chemical characteristics of 5 granoblastic samples collected during Expedition 312 at the root of the sheeted dyke complex and between two gabbroic horizons were also acquired for comparison. Samples collected during IODP Expedition 335 are mainly fine grained oxide grabbronorites composed of two pyroxenes, plagioclases and oxides (ilmenite, magnetite) with more or less amphiboles, sulphides, quartz and accessory minerals. Orthopyroxene Shape (roundish or anhedral), the amount of oxide inclusions in clinopyroxene and plagioclase morphology (laths or triple-junction mosaic) indicate various recrystallisation degrees. Plagioclases show a strong zoning in the less recrystallised samples, which tend to disappear with increasing recrystallisation degree. Samples show usually low alteration (less than 10%) with moderate transformation of pyroxenes into talc or actinolite. Samples from Expedition 312 show finer grains, higher degree of alteration (up to 30%), and weaker recrystallisation. They are mainly composed of plagioclases, amphibole and oxides

  7. Xenoliths of Phl- Ol breccia and lamproite- like dykes in Udachanaya pipe

    NASA Astrophysics Data System (ADS)

    Ashchepkov, Igor; Ntaflos, Theodoros; Samsonov, Gerasim; Mityukhin, Sergei; Khmelnikova, Olga

    2013-04-01

    Probe laser system (analyst S.V. Palessky). The Cpx from the contact zone from the last sample show the incline REE pattern with LREE to 100 and hump near Pr. The incompatible element (IK) are more plat near 70 C1 with depression in Nb -Ta. The REE patterns for phlogopite are more inclined. Phls as well as bulk rock demonstrate inflected in Gd patterns consisting from two highly inclined parts suggesting mixing of two highly evolved liquids. Spiderdiagrams show continuous PhlL enrichment in IK (smaller in HFSE and Pb) and extremely high Ba, Rb (1000C1). The Cr- low garnet megacryst show elevated LREE and high HREE and moderate enrichment in IK. Phl-Ol rocks represent the last stage dyke stage of H2O rich melts evolution close to kimberlite II which produced Phl metasomatism in the lithosphere base (Ashchepkov et al., 2012, 2013). RBRF grant 11-05-00060.

  8. The French Guyana doleritic dykes: geochemical evidence of three populations and new data for the Jurassic Central Atlantic Magmatic Province

    NASA Astrophysics Data System (ADS)

    Nomade, S.; Pouclet, A.; Chen, Y.

    2002-12-01

    A petrographic and geochemical study of 15 Early Jurassic and 7 Proterozoic dolerites of French Guyana, and of one Jurassic dolerite from Ivory-Coast were carried out. The Early Jurassic SSW-NNE trending dykes have doleritic aphyric or gabbroic phyric texture. Their chemical compositions, slightly under-saturated to over-saturated, show moderate to low Mg-ratios (63-36), high TiO 2 contents (1.85-3.56 wt.%), weak rare earth element fractionation [1.8<(La/Yb) n <4.6], negative Sr-anomalies (0.41dykes were identified in French Guyana. Compared to the Jurassic ones the Proterozoic dykes have NNW-SSE and E-W trending direction, more important LILE enrichment, low TiO 2 contents (<2 wt%) and Nb-Ta negative anomalies. Their calc-alkaline signature could be the result of a previous subduction and may be related to the 1800 Ma Venturi-Tapajós event, which contaminated the mantle source.

  9. Seismic constraints on a large dyking event and initiation of a transform fault zone in Western Gulf of Aden

    NASA Astrophysics Data System (ADS)

    Ahmed, AbdulHakim; Doubre, Cecile; Leroy, Sylvie; Perrot, Julie; Audin, Laurence; Rolandone, Frederique; Keir, Derek; Al-Ganad, Ismael; Sholan, Jamal; Khanbari, Khaled; Mohamed, Kassim; Vergne, Jerome; Jacques, Eric; Nercessian, Alex

    2013-04-01

    In November 2010, a large number of events were recorded by the world seismic networks showing important activity occurring along the western part of the Aden Ridge. West of the Shulka El Sheik fracture zone, events in this large seismic swarm (magnitudes above 5) occurred in a complex area, where the change of both the ridge direction and the bathymetry suggest the propagation of the ridge into a continental lithosphere and the influence of the Afar plume. We combine several sets of data from permanent networks and temporary 3C broad stations installed after the beginning of the event along the southern and eastern coasts of Yemen and Djibouti respectively, we located more than 600 earthquakes with magnitudes ranging from 2.5 to 5.6 that occurred during the first months following the first event. The spatial distribution of the main seismicity reveals a very clear N115° -trending alignment, parallel to the mean direction of the en-echelon spreading segments that form the ridge at this longitude. Half of the events, which represent half of the total seismic energy released during the first months, are located in the central third section of the segment. Here several volcanic cones and recent lava flows observed from bathymetric and acoustic reflectivity data during the Tadjouraden cruise (Audin, 1999, Dauteuil et al., 2001) constitute the sea floor. In addition to this main activity, two small groups of events suggest the activiation of landslides into a large fan and the activity in a volcanic area 50 km due east from the main active zone. The time evolution of the seismicity shows several bursts of activity. Some of them are clearly related to sudden activities within the volcanic areas, when others exhibit horizontal migration of the events, with velocity around ˜ 1 km/h. The time-space evolution of the seismicity clearly reveals the intrusion of dykes associated with magma propagation from the crustal magmatic centres into the rift zone. Taking into account

  10. Modelling of The Dyke Emplacement Leading To The Etna July 2001 Eruption Through Continuous Tilt and GPS Data

    NASA Astrophysics Data System (ADS)

    Bonaccorso, A.; Aloisi, M.; Mattia, A.

    During the June 2001 eruption of Mt. Etna the continuous ground deformation mon- itoring have been recorded through tilt (9 stations) and GPS (11 stations) permanent networks. The evolution of the July crisis preceding and leading to the eruption has been monitored through the tilt and GPS continuous measurements, which constrained in time the final intrusion and inferred the position and geometry of the uprising dyke. The tilt signals, which record 48 samples/day, fixed the time action of the intrusion, whose main effects are recorded during 13-15 July in concomitance with the first days of the seismic crisis. In particular, the high precision long-base mercury tiltmeter, in- stalled at Pizzi Deneri observatory in the high north-eastern flank close to the crater area, showed very well the continuous deformation during the dyke emplacement. The deformation pattern, at the entire volcano scale, was well characterised by the daily measurement sessions recorded at the GPS permanent network. The variations recorded at the permanent GPS stations started from July 13 and, in agreement with tilt recordings, were mainly cumulated in the following two days. The GPS measurements showed horizontal displacement vectors much bigger than vertical changes. The defor- mation pattern indicates the response to a tensile mechanisms that appears compatible with an intrusion in the volcano edifice along a ca. N-S direction. In this poster we show the modelling of the marked ground deformation changes recorded in the days before the eruption starting. The first results show that a tensile crack with an opening dislocation of ~3 m. and crossing the entire edifice, south-west to the crater area, can explain the recorded deformation pattern. The location of the modelled tensile source fits the seismogenetic zone characterized by epicenters aligned in a ca. N-S direction with the foci clustered in the last shallow kilometers. The ground deformation pat- tern associated with the final

  11. Electromagnetic induction in a conductive strip in a medium of contrasting conductivity: application to VLF and MT above molten dykes

    NASA Astrophysics Data System (ADS)

    Davis, Paul M.

    2014-11-01

    Very low frequency (VLF) electromagnetic waves that penetrate conductive magma-filled dykes generate secondary fields on the surface that can be used to invert for dyke properties. The model used for the interpretation calculates currents induced in a conductive strip by an inducing field that decays exponentially with depth due to the conductivity of the surrounding medium. The differential equations are integrated to give an inhomogeneous Fredholm equation of the second kind with a kernel consisting of a modified Bessel function of the second kind. Numerical methods are typically used to solve for the induced currents in the strip. In this paper, we apply a modified Galerkin-Chebyshev method, which involves separating the kernel into source and field spectra and integrating the source terms to obtain a matrix equation for the unknown coefficients. The incident wave is expressed as a Chebyshev series. The modified Bessel function is separated into a logarithmic singularity and a non-singular remainder, both of which are expanded in complex Chebyshev polynomials. The Chebyshev coefficients for the remainder are evaluated using a fast Fourier transform, while the logarithmic term and incident field have analytic series. The deconvolution then involves a matrix inversion. The results depend on the ratio of strip-size to skin-depth. For infinite skin-depth and a singular conductivity distribution given by τ_0 a/√{a^2 - z^2 } (where τ0 is the conductance, a is the half-length and z the distance from the centre), Parker gives an analytic solution. We present a similar analytic series solution for the finite skin-depth case, where the size to skin depth ratio is small. Results are presented for different ratios of size to skin depth that can be compared with numerical solutions. We compare full-space and half-space solutions. A fit of the model to VLF data taken above a magma filled dykes in Hawaii and Mt Etna demonstrates that while properties such as depth to top

  12. Dyke leakage localization and hydraulic permeability estimation through self-potential and hydro-acoustic measurements: Self-potential 'abacus' diagram for hydraulic permeability estimation and uncertainty computation

    NASA Astrophysics Data System (ADS)

    Bolève, A.; Vandemeulebrouck, J.; Grangeon, J.

    2012-11-01

    In the present study, we propose the combination of two geophysical techniques, which we have applied to a dyke located in southeastern France that has a visible downstream flood area: the self-potential (SP) and hydro-acoustic methods. These methods are sensitive to two different types of signals: electric signals and water-soil pressure disturbances, respectively. The advantages of the SP technique lie in the high rate of data acquisition, which allows assessment of long dykes, and direct diagnosis in terms of leakage area delimitation and quantification. Coupled with punctual hydro-acoustic cartography, a leakage position can be precisely located, therefore allowing specific remediation decisions with regard to the results of the geophysical investigation. Here, the precise localization of leakage from an earth dyke has been identified using SP and hydro-acoustic signals, with the permeability of the preferential fluid flow area estimated by forward SP modeling. Moreover, we propose a general 'abacus' diagram for the estimation of hydraulic permeability of dyke leakage according to the magnitude of over water SP anomalies and the associated uncertainty.

  13. Paleomagnetism of Devonian dykes in the northern Kola Peninsula and its bearing on the apparent polar wander path of Baltica in the Precambrian

    NASA Astrophysics Data System (ADS)

    Veselovskiy, Roman V.; Bazhenov, Mikhail L.; Arzamastsev, Andrey A.

    2016-04-01

    Mafic dykes and large alkaline and carbonatite intrusions of Middle-Late Devonian age are widespread on the Kola Peninsula in NE Fennoscandia. These magmatic rocks are well characterized with petrographic, geochemical and geochronological data but no paleomagnetic results have been reported yet. We studied dolerite dykes from the northern part of the Peninsula and isolated three paleomagnetic components in these rocks. A low-temperature component is aligned along the present-day field, while a major constituent of natural remanent magnetization is an intermediate-temperature component (Decl. = 79.6°, Inc. = 78.5°, α95 = 5,9°, N = 17 sites) that is present in most Devonian dykes but is found in some baked metamorphic rocks and Proterozoic dykes too. Finally, a primary Devonian component could be reliably isolated from two dykes only. Rock-magnetic studies point to presumably primary low-Ti titanomagnetite and/or pure magnetite as the main remanence carriers but also reveal alteration of the primary minerals and the formation of new magnetic phases. The directions of a major component differ from the Middle Paleozoic reference data for Baltica but closely match those for the 190 ± 10 Ma interval recalculated from the apparent polar wander path of the craton. We assume that this Early Jurassic component is a low-temperature overprint of chemical origin. The main impact of the new results is not to mid-Paleozoic or Early Mesozoic times but to much older epochs. Analysis of paleomagnetic data shows that the directionally similar remanences are present in objects with the ages ranging from 500 Ma to ~ 2 Ga over entire Fennoscandia. Hence we argue that an Early Jurassic remagnetization is of regional extent but cannot link it to a certain process and a certain tectonic event. If true, this hypothesis necessitates a major revision of the APWP for Baltica over a wide time interval.

  14. Impacts of dyke development in flood prone areas in the Vietnamese Mekong Delta to downstream flood hazard

    NASA Astrophysics Data System (ADS)

    Khanh Triet Nguyen, Van; Dung Nguyen, Viet; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

    2016-04-01

    The Vietnamese Mekong Delta (VMD) plays an important role in food security and socio-economic development of the country. Being a low-lying coastal region, the VMD is particularly susceptible to both riverine and tidal floods, which provide, on (the) one hand, the basis for the rich agricultural production and the livelihood of the people, but on the other hand pose a considerable hazard depending on the severity of the floods. But despite of potentially hazardous flood, the area remain active as a rice granary due to its nutrient-rich soils and sediment input, and dense waterways, canals and the long standing experience of the population living with floods. In response to both farmers' requests and governmental plans, the construction of flood protection infrastructure in the delta progressed rapidly in the last twenty years, notably at areas prone to deep flooding, i.e. the Plain of Reeds (PoR) and Long Xuyen Quadrangle (LXQ). Triple rice cropping becomes possible in farmlands enclosed by "full-dykes", i.e. dykes strong and high enough to prevent flooding of the flood plains for most of the floods. In these protected flood plains rice can be grown even during the peak flood period (September to November). However, little is known about the possibly (and already alleged) negative impacts of this fully flood protection measure to downstream areas. This study aims at quantifying how the flood regime in the lower part of the VMD (e.g. Can Tho, My Thuan, …) has been changed in the last 2 recent "big flood" events of 2000 and 2011 due to the construction of the full-dyke system in the upper part. First, an evaluation of 35 years of daily water level data was performed in order to detect trends at key gauging stations: Kratie: upper boundary of the Delta, Tan Chau and Chau Doc: areas with full-dyke construction, Can Tho and My Thuan: downstream. Results from the Mann-Kendall (MK) test show a decreasing trend of the annual maximum water level at 3 stations Kratie, Tan

  15. Petrogenesis of Mesoproterozoic lamproite dykes from the Garledinne (Banganapalle) cluster, south-western Cuddapah Basin, southern India

    NASA Astrophysics Data System (ADS)

    Rao, N. V. Chalapathi; Atiullah; Kumar, Alok; Sahoo, Samarendra; Nanda, Purnendu; Chahong, Ngazimpi; Lehmann, B.; Rao, K. V. S.

    2016-04-01

    We report mineral chemistry and whole-rock major and trace-element geochemistry for a recent find of Mesoproterozoic (~1.4 Ga) lamproites from the Garledinne (Banganapalle) cluster, south-western part of the Paleo-Mesoproterozoic Cuddapah Basin, southern India. The Garledinne lamproites occur as WNW-ESE-trending dykes that have undergone varying degree of pervasive silicification and carbonate alteration. Nevertheless, their overall texture and relict mineralogy remain intact and provide important insights into the nature of their magmas. The lamproite dykes have porphyritic to weakly porphyritic textures comprising pseudomorphed olivine macrocrysts and microphenocrysts, titanian phlogopite microphenocrysts, spinel having a compositional range from chromite to rarely magnesiochromite, Sr-rich apatite and niobian rutile. The Garledinne and other Cuddapah Basin lamproites (Chelima and Zangamarajupalle) collectively lack sanidine, clinopyroxene, potassic richterite, and titanite and are thus mineralogically distinct from the nearby Mesoproterozoic lamproites (Krishna and Ramadugu) in the Eastern Dharwar Craton, southern India. The strong correlation between various major and trace elements coupled with high abundances of incompatible and compatible trace elements imply that alteration and crustal contamination have had a limited effect on the whole-rock geochemistry (apart from K2O and CaO) of the Garledinne lamproites and that olivine fractionation played an important role in their evolution. The Garledinne lamproites represent small-degree partial melts derived from a refractory (previously melt extracted) peridotitic mantle source that was subsequently metasomatised (enriched) by carbonate-rich fluids/melts within the garnet stability field. The involvement of multiple reservoirs (sub-continental lithospheric mantle and asthenosphere) has been inferred in their genesis. The emplacement of the Garledinne lamproites is linked to extensional events, across the various

  16. Caractérisation géochimique des dykes basiques du massif de les Saras (Mayombe Congolais, Afrique Centrale): conséquences géodynamiquesGeochemical characterizations of basic dykes of the Saras massif (Congolese Mayombe Belt, Central Africa): geodynamic implications

    NASA Astrophysics Data System (ADS)

    Boni, J. Mpemba; Vellutini, P. J.

    1992-02-01

    The Saras granodioritic massif is one of the Eburnean intrusive plutons of the Mayombe Belt. (South-West Congo, Central Africa) It is crosscut by a system of basic dykes, of diversified composition. Petrographic data and a comparative geochemical study, using incompatible trace elements, shows a tholeiitic transitional affinity, and allow us to suggest that these dykes are continental basaltic suites, from extensive areas. This basic magmatism, scattered in the whole Congo Craton, marks a widespread extensional episode in relation with the formation of subsidence basins or true aulacogens, at about 970 Ma (Pan African).

  17. Petrology, geochronology and emplacement model of the giant 1.37 Ga arcuate Lake Victoria Dyke Swarm on the margin of a large igneous province in eastern Africa

    NASA Astrophysics Data System (ADS)

    Mäkitie, Hannu; Data, Gabriel; Isabirye, Edward; Mänttäri, Irmeli; Huhma, Hannu; Klausen, Martin B.; Pakkanen, Lassi; Virransalo, Petri

    2014-09-01

    A comprehensive description of the petrography, geochemical composition, Sm-Nd data and intrinsic field relationships of a giant arcuate Mesoproterozoic mafic dyke swarm in SW Uganda is presented for the first time. The swarm is ∼100 km wide and mainly hosted in the Palaeoproterozoic Rwenzori Belt between the Mesoproterozoic Karagwe-Ankole Belt and the Archaean Uganda Block. The dykes trend NW-SE across Uganda, but can be correlated across Lake Victoria to another set of arcuate aeromagnetic anomalies that continue southwards into Tanzania, resulting in a remarkably large semi-circular swarm with an outer diameter of ∼500 km. We propose that this unique giant dyke structure be named the Lake Victoria Dyke Swarm (LVDS). The dykes are tholeiites with Mg numbers between 0.69 and 0.44, and with inherited marked negative Nb and P anomalies in spider diagrams. Two dykes provide Sm-Nd mineral ages of 1368 ± 41 Ma and 1374 ± 42 Ma, with initial εNd values of -2.3 and -3.2, and 87Sr/86Sr ratios of ∼0.706-0.709. Geotectonic discrimination diagrams for the swarm exhibit more arc type than within-plate tectonic signatures, but this is in accordance with systematic enrichments in LREE, U and Th in the dolerites, more likely due to the involvement of the continental lithosphere during their petrogenesis. The LVDS is coeval with a regional ∼1375 Ma bimodal magmatic event across nearby Burundi, Rwanda and NW Tanzania, which can collectively be viewed as a large igneous province (LIP). It also indicates that the nearby Karagwe-Ankole Belt sequences - bracketed between 1.78 and 1.37 Ga and assumed by some to have been deposited within intracratonic basins - were capped by flood basalts that have subsequently been removed by erosion. Different geochemical signatures (e.g. LaN/SmN) suggest that most of the arcuate swarm was derived from an enriched SCLM, whereas related intrusions in the centre of this semi-circular segment have more or less enriched asthenospheric mantle

  18. Petrogenesis and tectonic implications of the Neoproterozoic Datian mafic-ultramafic dykes in the Panzhihua area, western Yangtze Block, SW China

    NASA Astrophysics Data System (ADS)

    Yang, Yi-Jin; Zhu, Wei-Guang; Bai, Zhong-Jie; Zhong, Hong; Ye, Xian-Tao; Fan, Hong-Peng

    2016-03-01

    Mafic-ultramafic dykes are important geological markers that can punctuate the onset of crustal extension during the breakup of a continent and provide valuable information on the mantle source. This study reports secondary ion mass spectroscopy zircon and baddeleyite U-Pb ages, elemental and Nd isotopic data for the Datian mafic-ultramafic dykes in the Panzhihua area, western Yangtze Block, SW China. Two kinds of rocks are confirmed: the picritic rock and the dolerite. Based on petrographic and geochemical features, the dolerite dykes are further subdivided into two groups: Group I mafic and Group II mafic dykes, which emplaced at ~760 Ma (zircon U-Pb) and ~800 Ma (zircon and baddeleyite U-Pb), respectively. All samples from the picritic rocks and the Group I mafic rocks show the features of high-Ti and alkaline basaltic magma in composition as well as "humped" trace element patterns, which are similar to those of typical alkaline basalts associated with continental rifts except for the slightly negative Nb-Ta anomalies. The Group II mafic rocks display the features of low-Ti and tholeiitic magma, moderately enriched in LILE and LREE, and characterized by distinctively negative Nb-Ta anomalies. The primary magmas of the picritic rocks and the Group I mafic rocks were generated from ca 25 % partial melting of an OIB-like, Nd isotopically depleted but incompatible elements relatively enriched mantle source within a garnet stable field. The Group II mafic rocks crystallized from crustal contaminated mafic magmas that were derived from a spinel-bearing sub-continental lithospheric mantle source, because of low ratios of La/Yb, Ti/Y and Sm/Yb. Geochemical features suggest that these groups of mafic-ultramafic dykes were formed in a continental rift setting, but derived from different mantle sources. In combination with other Neoproterozoic igneous rocks in the western margin of Yangtze Block, it is suggested that the Datian mafic-ultramafic dykes in the Panzhihua area

  19. Petrological and geochemical constraints on the origin of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc, NE Turkey

    NASA Astrophysics Data System (ADS)

    Aydin, Faruk; Oguz, Simge; Baser, Rasim; Uysal, Ibrahim; Sen, Cüneyt; Karsli, Orhan; Kandemir, Raif

    2015-04-01

    Geological, petrographical and geochemical data of mafic dykes intruding the composite Kaçkar Pluton from the eastern Blacksea magmatic arc (EBMA), NE Turkey, provide new insights into the nature of the metasomatizing agents in subcontinental lithospheric mantle beneath the region during the late Mesozoic-early Tertiary. Mafic dykes from the Çaykara and Hayrat (Trabzon), and also Ikizdere (Rize) areas from the northern margin of the EBMA consist of basalts, dolerites, lamprophyres (basic member) and lesser basaltic andesites and trachyandesites (evolved member). All dykes have no deformation and metamorphism. The outcrops of these dykes vary, with thickness from 0.2 to 10 m. and visible length from 3 to 20 m. In general, the mafic dykes dip steeply and cut directly across the Kaçkar Pluton, and show NW- and NE-trending, roughly parallel to the orientations of the EBMA main faults. Most of the dyke samples display subaphyric to porphyritic texture with phenocrysts of plagioclase (up to 10%), clinopyroxene (5-20%), amphibole (5-15%), and some contain variable amount of biotite (5-20%), lesser quartz (1-2%), and minor euhedral zircon, apatite and Fe-Ti oxides. The basic members of the mafic dykes have SiO2 of 44.1-51.9%, MgO of 4.5-12.1%, and TiO2 >mostly 0.8% (up to 2.3%) with K2O+Na2O of 1.3-6.6% with mostly subalkaline character. They are relatively high in mg-number (0.45-0.73) and transition metals (V=171-376 ppm, Co=22-45 ppm, Ni=3-148 ppm, and Sc=21-49 ppm). The evolved members of the dykes exhibit relatively higher SiO2 (57.1-60.2%) and K2O+Na2O (5.6-9.0%), and lower MgO (2.2-5.9%) and TiO2 (0.5-0.8%) contents than those from the basic dykes. Also, these samples have slightly low mg-number (0.41-0.65) and transition metals (V=99-172 ppm, Co=9-22 ppm, Ni=1-43 ppm, and Sc=9-20 ppm). In the Harker diagrams, all samples of the mafic dykes form a continuous array, and exhibit similar geochemical characteristics. In general, SiO2 inversely correlates with MgO, Fe

  20. Mesoproterozoic mafic and carbonatitic dykes from the northern margin of the North China Craton: Implications for the final breakup of Columbia supercontinent

    NASA Astrophysics Data System (ADS)

    Yang, Kui-Feng; Fan, Hong-Rui; Santosh, M.; Hu, Fang-Fang; Wang, Kai-Yi

    2011-01-01

    The North China Craton (NCC) has figured prominently in recent reconstructions on the Paleoproterozoic supercontinent Columbia. Here we report abundant carbonatitic and mafic dykes from around the giant Bayan Obo rare earth element deposit in the northern margin of the NCC, and present geochemical and isotope geochronological data. The carbonatite (1354 ± 59 Ma) and mafic dykes (1227 ± 60 Ma) have comparable whole rock Sm-Nd isochron ages and Sr-Nd isotope compositions, suggesting a common source characteristic. Their geochemical characters including major and trace elements as well as REE patterns also attest to a common tectonic environment of magma generation and emplacement within a continental margin rift. The extensive mafic and carbonatitic magmatisms are associated with an extensional event that resulted in the formation of the Bayan Obo rift in the northern margin of the NCC, which we correlate with the final stages of fragmentation of the Columbia supercontinent amalgam.

  1. Sheeted and bulbous pluton intrusion mechanisms of a small granitoid from southeastern Australia: implications for dyke-to-pluton transformation during emplacement

    NASA Astrophysics Data System (ADS)

    Fowler, T. J.

    1994-06-01

    The small late syn-tectonic Carboniferous Davys Creek Granite (DCG) of southeastern Australia consists of microgranitic intrusive bodies of diverse geometry and structure. These bodies include: (1) subvertical concordant sheets; (2) bulbous peneconcordant plutons with apophyses and discordant lobes; and (3) subvertical dykes and stocks. The sequence of changing intrusive style is broadly 1-2-3. Transition from 1 to 2 was probably a response to rising magma pressures or declining tectonic stresses. The λ parameter of Emerman and Marrett (1990), which discriminates between stable sheet-like and potential stock/pluton/batholith emplacement modes, adequately predicts the transitions between sheet and pluton emplacements for the DCG. Ductile dyking along actively forming foliations appears to have been an important early intrusive mechanism. A transition from sheet to bulbous pluton intrusion style is suggested to have been in response to magma pressure increases.

  2. Contribution of the FUTUREVOLC project to the study of segmented lateral dyke growth in the 2014 rifting event at Bárðarbunga volcanic system, Iceland

    NASA Astrophysics Data System (ADS)

    Sigmundsson, Freysteinn; Hooper, Andrew; Hreinsdóttir, Sigrún; Vogfjörd, Kristín S.; Ófeigsson, Benedikt; Rafn Heimisson, Elías; Dumont, Stéphanie; Parks, Michelle; Spaans, Karsten; Guðmundsson, Gunnar B.; Drouin, Vincent; Árnadóttir, Thóra; Jónsdóttir, Kristín; Gudmundsson, Magnús T.; Samsonov, Sergey; Brandsdóttir, Bryndís; White, Robert S.; Ágústsdóttir, Thorbjörg; Björnsson, Helgi; Bean, Christopher J.

    2015-04-01

    The FUTUREVOLC project (a 26-partner project funded by FP7 Environment Programme of the European Commission, addressing topic "Long-term monitoring experiment in geologically active regions of Europe prone to natural hazards: the Supersite concept) set aims to (i) establish an innovative volcano monitoring system and strategy, (ii) develop new methods for near real-time integration of multi-parametric datasets, (iii) apply a seamless transdisciplinary approach to further scientific understanding of magmatic processes, and (iv) to improve delivery, quality and timeliness of transdisciplinary information from monitoring scientists to civil protection. The project duration is 1 October 2012 - 31 March 2016. Unrest and volcanic activity since August 2014 at one of the focus areas of the project in Iceland, at the Bárðarbunga volcanic system, near the middle of the project duration, has offered unique opportunities for this project. On 16 August 2014 an intense seismic swarm started in Bárðarbunga, the beginning of a major volcano-tectonic rifting event forming over 45 km long dyke extending from the caldera to Holuhraun lava field outside the northern margin of Vatnajökull. A large basaltic, effusive fissure eruption began in Holuhraun on 31 August which had by January formed a lava field with a volume in excess of one cubic kilometre. We document how the FUTUREVOLC project has contributed to the study and response to the subsurface dyke formation, through increased seismic and geodetic coverage and joint interpreation of the data. The dyke intrusion in the Bárðarbunga volcanic system, grew laterally for over 45 km at a variable rate, with an influence of topography on the direction of propagation. Barriers at the ends of each segment were overcome by the build-up of pressure in the dyke end; then a new segment formed and dyke lengthening temporarily peaked. The dyke evolution, which occurred over 14 days, was revealed by propagating seismicity, ground

  3. Platinum-group element concentrations in pyrite from the Main Sulfide Zone of the Great Dyke of Zimbabwe

    NASA Astrophysics Data System (ADS)

    Piña, R.; Gervilla, F.; Barnes, S.-J.; Oberthür, T.; Lunar, R.

    2016-02-01

    The Main Sulfide Zone (MSZ) of the Great Dyke of Zimbabwe hosts the world's second largest resource of platinum-group elements (PGE) after the Bushveld Complex in South Africa. The sulfide assemblage of the MSZ comprises pyrrhotite, pentlandite, chalcopyrite, and minor pyrite. Recently, several studies have observed in a number of Ni-Cu-PGE ore deposits that pyrite may host significant amounts of PGE, particularly Pt and Rh. In this study, we have determined PGE and other trace element contents in pyrite from the Hartley, Ngezi, Unki, and Mimosa mines of the Great Dyke by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Based on the textures and PGE contents, two types of pyrite can be differentiated. Py1 occurs as individual euhedral or subhedral grains or clusters of crystals mostly within chalcopyrite and pentlandite, in some cases in the form of symplectitic intergrowths, and is PGE rich (up to 99 ppm Pt and 61 ppm Rh; 1.7 to 47.1 ppm Ru, 0.1 to 7.8 ppm Os, and 1.2 to 20.2 ppm Ir). Py2 occurs as small individual euhedral or subhedral crystals within pyrrhotite, pentlandite, and less frequently within chalcopyrite and silicates and has low PGE contents (<0.11 ppm Pt, <0.34 ppm Rh, <2.5 ppm Ru, <0.37 ppm Ir, and <0.40 ppm Os). Py1 contains higher Os, Ir, Ru, Rh, and Pt contents than the associated pyrrhotite, pentlandite, and chalcopyrite, whereas Py2 has similar PGE contents as coexisting pyrrhotite and pentlandite. Based on the textural relationships, two different origins are attributed for each pyrite type. Py1 intergrowth with pentlandite and chalcopyrite is inferred to have formed by late, low temperature (<300 °C) decomposition of residual Ni-rich monosulfide solid solution, whereas Py2 is suggested to have formed by replacement of pyrrhotite and pentlandite caused by late magmatic/hydrothermal fluids.

  4. 40Ar/39Ar dating of basaltic dykes swarm in Western Cameroon: Evidence of Late Paleozoic and Mesozoic magmatism in the corridor of the Cameroon Line

    NASA Astrophysics Data System (ADS)

    Tchouankoue, Jean Pierre; Simeni Wambo, Nicole Armelle; Kagou Dongmo, Armand; Li, Xian-Hua

    2014-05-01

    40Ar/39Ar ages of three basalt dykes that intrude the Precambrian basement in the southern continental part of the Cretaceous Cameroon Line are presented. Specimen were sampled at Dschang, Maham and Kendem (Cameroon). The ages obtained are 421.3 ± 3.5 Ma (Dschang), 404.22 ± 3.51 Ma (Maham), and 192.10 ± 7.45 Ma (Kendem). The Dschang and Maham samples yield a relatively undisturbed spectrum while the Kendem sample shows an excess of argon but with plateau ages in the frame of the Mesozoic. Plateau ages at Dschang, Maham and Kendem represent more than 80% of the total 39Ar released and are interpreted as emplacement ages. 40Ar/39Ar dating results confirm Devonian and Jurassic K/Ar ages obtained from similar dykes of the same region. Geochemically, the basalt dykes are subalkaline in composition with 45-50 wt.% SiO2. Incompatible trace elements and rare earth elements are lower than that of the Cameroon Line basalts. Overall geochemical characteristics of the basalt dykes much more closely resemble those of tholeiites of the Benue Through in Nigeria that are interpreted as related to the opening of the Atlantic Ocean. The combination of 40Ar/39Ar ages, major, trace and rare earth elements geochemistry data demonstrate a magmatic phase that is significantly older and different of that of the Cretaceous Cameroon Line and younger than the dominantly granitic Neoproterozoic to early Paleozoic magmatism in the region. These findings offer new clues for a better understanding of the tectonic history of the region, particularly the origin of the Cameroon Line and Africa-South America pre-drift reconstitutions.

  5. Mingling of carbonate and silicate magmas under turbulent flow conditions: Evidence from rock textures and mineral chemistry in sub-volcanic carbonatite dykes, Chagatai, Uzbekistan

    NASA Astrophysics Data System (ADS)

    Moore, K. R.; Wall, F.; Divaev, F. K.; Savatenkov, V. M.

    2009-06-01

    The Triassic Chagatai Complex, Uzbekistan, comprises explosive pipes and dykes, dominantly of silicocarbonatite composition, with cross-cutting relationships indicating multi-stage emplacement. Although the dykes have been reported as diamond-bearing, they have not previously undergone detailed investigation in terms of their mineral chemistry or rock texture. The xenolith-rich dykes contain irregularly-shaped microscopic magmatic enclaves of silicate composition within carbonatite magma and corroded microphenocrysts with crystal overgrowths that record synmagmatic geochemical disequilibrium. Quench crystals of apatite and aegirine, and anhedral baryte, which formed after corrosion of apatite and magnetite microphenocrysts but prior to formation of crystal overgrowths and mantles, indicate contemporaneous rapid undercooling. The anhedral baryte formed as a by-product of an oxidising hydrous reaction from Ba-rich biotite and pyrite to chlorite. The rock and microphenocryst textures suggest that mingling between two magmas occurred and a post-mingling mineral assemblage, including baryte, crystallised in a partially hybridised heterogeneous magma. An initial carbonatite mineral assemblage is identified as calcite + magnetite + apatite ± augite ± barium-rich biotite ± melilite ± pyrite. Changes in mineral chemistry of the carbonatite assemblage that are contemporaneous with the disequilibrium reaction textures suggest addition of a hydrous, Na-Si-Al-rich magma, and the mineral assemblage in the magmatic enclaves is similar to that of trachyte dykes in the Chagatai Complex. Using primarily rock textures and mineral chemistry, supported by mass balance calculations and isotope data, the silicate material is interpreted as a hydrous trachyte magma that had assimilated upper crustal material. The trachyte magma was entrained by carbonatite that was rapidly and turbulently ascending through the crust, shortly before emplacement as silicocarbonatite. The interpretation

  6. Surface displacements on faults triggered by slow magma transfers between dyke injections in the 2005-2010 rifting episode at Dabbahu-Manda-Hararo rift (Afar, Ethiopia)

    NASA Astrophysics Data System (ADS)

    Dumont, S.; Socquet, A.; Grandin, R.; Doubre, C.; Klinger, Y.

    2016-01-01

    The rifting episode that occurred in Dabbahu-Manda-Hararo (Ethiopia) between 2005 and 2010 during which 14 dyke intrusions were emitted, was a unique opportunity to study interactions between tectonic deformation and magmatic processes. While magmatism has been shown to control primarily the spatial and temporal distribution of dyke intrusions during this accretion sequence, the role of faults in accommodating plate spreading in rift segments is poorly understood. During interdyking periods, transient ground deformation due to magma movement is generally observed. Investigating such a small-scale deformation and in particular the movement along faults during these periods will help understanding the factors that trigger fault movement in magmatic rifts. We analyse fault activity during three interdyking periods: 2006 December-June (d0-d1), 2007 January-July (d5-d6) and 2009 November-January (d10-d11). The time-space evolution of surface displacements along ˜700 faults is derived from pairs of ascending and descending SAR interferograms. Surface slip distributions are then compared with codyking ground deformation fields. The results show that faults are mainly activated above the areas affected by magma emplacement during interdyking periods. A detailed analysis of brittle deformation during the six months following the 2005 September intrusion shows asymmetric deformation on the rift shoulders, with significant opening on faults located to the west of the dyke. We explain this feature by the activation of westward dipping pre-existing faults, with block rotations in between. In addition, we observe that the strip encompassing the activated faults narrows by 30 per cent from co- to interdyking period. This suggests that magma keeps migrating to shallower depths after the dyke intrusion. During a rifting episode, activation of faults in a pre-existing fracture network therefore seems to be mainly controlled by deep magma processes.

  7. Geochemical studies and petrogenesis of ~2.21-2.22 Ga Kunigal mafic dyke swarm (trending N-S to NNW-SSE) from eastern Dharwar craton, India: implications for Paleoproterozoic large igneous provinces and supercraton superia

    NASA Astrophysics Data System (ADS)

    Srivastava, Rajesh K.; Jayananda, M.; Gautam, Gulab C.; Samal, Amiya K.

    2014-10-01

    The Archean eastern Dharwar craton is transacted by at least four major Proterozoic mafic dyke swarms. We present geochemical data for the ~2.21-2.22 Ga N-S to NNW-SSE trending Kunigal mafic dyke swarm of the eastern Dharwar craton to address its petrogenesis and formation of large igneous province as well as spatial link to supercontinent history. It has a strike span of about 200 km; one dyke of this swarm runs ~300 km along the western margin of the Closepet granite. Texture and mineral compositions classify them as dolerite and olivine dolerite. They show compositions of high-iron tholeiites, high-magnesian tholeiites or picrites. Geochemical characteristics of the sampled dykes suggest their co-genetic nature and show variation from primitive (Mg#; as high as ~76) to evolved (differentiated) nature. Although geochemical characteristics indicate possibility of minor crustal contamination, they show their derivation from an uncontaminated mantle melt. These mafic dykes are probably evolved from a sub-alkaline basaltic magma generated by ~20 % batch melting of a depleted lherzolite mantle source and about 15-30 % olivine fractionation. Paleoproterozoic (~2.21-2.22 Ga) mafic magmatism is recognized globally as dyke swarms or gabbroic sill complexes in the Superior, Slave, North Atlantic, Fennoscandian and Pilbara cratons. Possible Paleoproterozoic Dharwar-Superior-North-Atlantic-Slave correlations are constrained with implications for the configuration of supercraton Superia.

  8. The Importance of Sampling Strategies on AMS Determination of Dykes II. Further Examples from the Kapaa Quarry, Koolau Volcano, Oahu, Hawaii

    NASA Astrophysics Data System (ADS)

    Mendoza-Borunda, R.; Herrero-Bervera, E.; Canon-Tapia, E.

    2012-12-01

    Recent work has suggested the convenience of dyke sampling along several profiles parallel and perpendicular to its walls to increase the probability of determining a geologically significant magma flow direction using anisotropy of magnetic susceptibility (AMS) measurements. For this work, we have resampled in great detail some dykes from the Kapaa Quarry, Koolau Volcano in Oahu Hawaii, comparing the results of a more detailed sampling scheme with those obtained previously with a traditional sampling scheme. In addition to the AMS results we will show magnetic properties, including magnetic grain sizes, Curie points and AMS measured at two different frequencies on a new MFK1-FA Spinner Kappabridge. Our results thus far provide further empirical evidence supporting the occurrence of a definite cyclic fabric acquisition during the emplacement of at least some of the dykes. This cyclic behavior can be captured using the new sampling scheme, but might be easily overlooked if the simple, more traditional sampling scheme is used. Consequently, previous claims concerning the advantages of adopting a more complex sampling scheme are justified since this approach can serve to reduce the uncertainty in the interpretation of AMS results.

  9. Alteration induced changes of magnetic fabric as exemplified by dykes of the Koolau volcanic range [rapid communication

    NASA Astrophysics Data System (ADS)

    Krása, David; Herrero-Bervera, Emilio

    2005-12-01

    We studied 93 samples from 8 basaltic dykes of the Koolau volcanic range on the island of Oahu,Hawaii,USA,to determine the influence of hydrothermal alteration on the magnetic fabric as determined by anisotropy of magnetic susceptibility (AMS) measurements. Rock magnetic as well as microscopic investigations show that only ≈25% of the samples have retained their original magnetomineralogical composition of unaltered Ti-poor titanomagnetite. The remaining samples have undergone hydrothermal alteration which transformed the primary magnetic phase into a granular intergrowth of titanomagnetite, titanomaghemite and hematite. In both sample groups,this magnetic phase occurs in coarse (tens of microns),irregularly shaped particles as well as interstitial clusters of smaller (< 5 μm) grains. Our investigations show that hydrothermal alteration does change the bulk susceptibility and the degree of anisotropy but not the directions of principal axes of the AMS ellipsoid which are predominantly corresponding to normal magnetic fabric. The stability of AMS directions, regardless of the degree of alteration, points towards the model of distribution anisotropy as the controlling factor for the observed magnetic fabric.

  10. The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile.

    PubMed

    Wicks, Charles; de la Llera, Juan Carlos; Lara, Luis E; Lowenstern, Jacob

    2011-10-20

    Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2 May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5 km depth in less than 4 hours (ref. 1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults. PMID:22012396

  11. RbSr and zircon study of ~2800 Ma Lewisian silicic gneisses from the Torridon Inlier of NW Scotland: Dyke intrusion and an open system

    NASA Astrophysics Data System (ADS)

    Chamberlain, V. E.; Lambert, R. St. J.; Holland, J. G.

    1986-01-01

    The Torridon Inlier of the Lewisian of Scotland contains ~30 sq. km of granodioritic gneisses. A coordinated study of this inlier, including detailed mapping, geochemical analyses and geochronological work, has indicated that Rb-Sr whole rock analyses yield "ages" that are functions of the local structural setting and of the chemistry and mineralogy of the rock, as well as of the overall geological history of the region. This Archean region has been invaded by a swarm of northwest striking dykes of Inverian (2400 to 2240 Ma) age, accompanied by new foliations and major structures. However, several structurally distinct areas, termed "pips", 1-2 km 2 in extent, are free of Inverian foliation and largely free of Inverian dykes. The 38 samples analysed for Rb and Sr scatter widely about a 2.66 Ma isochron; but give meaningful results only when subdivided according to their structural setting and lithology. A subset of silicic gneiss samples from the area most strongly overprinted by Inverian structures yields an age of 2240 ± 70 Ma with an initial 87Sr /86Sr of 0.7098 ± 18. A subset of samples from "pips" further north yields an age of2790± 100 Ma (initial 87Sr /86Sr = 0.7020± 10 ), identical to the 2780± 70 Ma U-Pb age obtained from zircon fractions separated from two of the samples. Samples from this northern district, located outside the "pips" in areas showing weak Inverian foliation, or within 50 m of Inverian dykes, or both, have grossly disturbed Rb-Sr systematics. The apparent ages of the felsic gneisses have been increased, while those of their mafic enclaves have been decreased (to as low as 1380 Ma). Field and geochemical evidence relate the increase directly to Rb loss and/or radiogenic Sr gain in the immediate vicinity of major dykes, which themselves have gained Rb and K by comparison with dykes elsewhere in the Lewisian. In terms of Rb-Sr work on complex terranes, these results must caution against direct interpretation of such data, especially in

  12. Mineralogy and geochemistry of alkaline basic dykes from the northern Indian plate: signs of more than one episode of rifting and associated magmatism

    NASA Astrophysics Data System (ADS)

    Sajid, Muhammad; Andersen, Jens; Arif, Mohammad

    2016-04-01

    Rift related magmatism during Permian time in the northern margin of Indian plate, north-west Pakistan is shown by the occurrence of roughly linear array of alkaline rocks in the region. The constituent rocks include alkali granites, granodiorites, nepheline syenites, carbonatites and dykes of basic composition. The field relations, mineralogy and whole rock geochemistry of these basic dykes has been investigated. Significant textural and mineralogical distinctions have divided the basic dykes into a) dolerite and b) epidote amphibolites, cross cutting other alkaline rocks and pre-Permian rocks in the region. Clinopyroxene having augitic composition is a major mineral in dolerite, however, it is completely absent in epidote amphibolites. Amphiboles in dolerites are brown coloured having pargasitic composition while it is green to light green in colour having the composition of magnesio-hornblende in epidote amphibolites. Compositionally different types of olivine are present in dolerites while it is absent in epidote amphibolites. Intra-plate tectonic settings for both the rock types has been interpreted by Hf-Ta-Th and FeO-MgO-Al2O3 discrimination plots. Lower Zr/Nb ratio (<10) and K/Ba ratio (amid 20-40) for both the rock types further show their affinity to within-plate magmatism. Dolerites show depletion in REEs and other incompatible elements as compared to epidote amphibolites. The equilibrium partial melting models from primitive mantle using Dy/Yb, La/Yb, Sm/Yb, La/Sm and Nb/Y ratios show that both of these dykes originate form spinel lherzolite mantle. However, the degrees of partial melting from mantle is different i.e. epidote amphibolite show smaller degree (<5%) of partial melting of mantle than the dolerites (<10%). The contrasting geochemistry suggests that both of these dykes originated from heterogeneous mantle in two pulses with different degrees partial melting followed by fractional crystallization. Compositional zoning in plagioclase and

  13. Magmatism and metamorphism at the sheeted dyke-gabbro transition zone: new insight from beerbachite from ODP/IODP Hole 1256D and Oman ophiolite

    NASA Astrophysics Data System (ADS)

    Python, Marie; Abily, Bénédicte; France, Lydéric

    2014-05-01

    During IODP Expedition 335, two-pyroxenes bearing granulites (beerbachites) were extensively recovered as drilling cuttings at the gabbro-sheeted dyke transition zone of ODP Hole 1256D (East Pacific Rise, 6°44.163'N, 91°56.061'W). This lithology results from high-temperature metamorphism of previously hydrothermally altered diabases, basalts and/or gabbros; the heat source likely stems from the melt lens located at the top of the magmatic chambers imaged along present-day fast-spreading ridges. This lithology, associated with gabbroic bodies, characterises the transition zone between the sheeted dyke complex and the uppermost gabbroic section and represents the interface between magmatic and hydrothermal convecting systems in an oceanic crust formed at fast-spreading ridges. Samples acquired during IODP Exp. 335 show a particularly high degree of recrystallisation and are characterised by the absence of hydrous phases like amphibole, suggesting very high-T metamorphism. The Beerbachites mineral chemical characteristics are rather homogeneous compared to gabbros or dolerite from the sheeted dyke but pyroxenes Mg#, Ti, Al and Cr contents as well as the anorthite content of plagioclase are closer to gabbro than dolerite. This similarity may be explained by two hypothesis: either beerbachites in Hole 1256D are metamorphosed gabbros, or they underwent a melt-rock reaction process with the gabbros parental magma and were re-equilibrated at high temperature until their mineral composition become similar to that of gabbros. The gabbro-sheeted dyke transition zone in the Oman ophiolite is also outlined by the presence of high grade metamorphic rocks. Fine grained granulites and amphibolites that may be derived from the transformation of altered sheeted dyke diabases are in direct contact with fresh gabbroic and troctolitic bodies which are themselves cross-cut by dolerite dykes. The observation of textures show that high-T recrystallisation occurred in the fine grained

  14. Composition of the ultramafic-mafic contact interval of the Great Dyke of Zimbabwe at Ngezi mine: Comparisons to the Bushveld Complex and implications for the origin of the PGE reefs

    NASA Astrophysics Data System (ADS)

    Maier, W. D.; Määttää, S.; Yang, S.; Oberthür, T.; Lahaye, Y.; Huhma, H.; Barnes, S.-J.

    2015-12-01

    The Great Dyke contains the world's second largest platinum resource after the Bushveld Complex. Isotopic and trace element data from the interval straddling the contact between the Ultramafic and Mafic Sequences of the Great Dyke indicate a less enriched composition than in the Bushveld Complex (Great Dyke: Sri 0.7024-0.7028, εNd mostly - 1 to + 1, Ce/Sm 2-6; Bushveld: Sri 705-0.709, εNd - 5 to - 7, Ce/Sm 5-15). These data are interpreted to reflect relatively moderate amounts of contamination of the Great Dyke parent magma. All analyzed isotopes show little variation across the Main Sulfide Zone and the ultramafic-mafic contact. This corroborates earlier work by other researchers that the Great Dyke crystallized from a single magma type. Mixing of compositionally distinct magmas, proposed to have caused sulfide melt saturation in the Bushveld Complex, seemingly played little or no role in the formation of the PGE mineralization in the Main Sulfide Zone, and neither did enhanced crustal contamination of specific magma batches. Instead, sulfide melt saturation of the magma was likely triggered by silicate fractionation. The mechanism of concentration of the sulfide melt remains uncertain, but theoretical considerations suggest that phase sorting in response to slumping of crystal mushes, possibly caused by chamber subsidence, played an important role. This model is consistent with the highly irregular, undulating nature of the contact between the mafic and ultramafic zones of the intrusion, in the hanging wall of the Main Sulfide Zone.

  15. Integrated Approach (Geophysics and Remote Sensing) to identify Water-bearing Dyke Swarms and Fractured Basement in the Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, L.; Sultan, M.; Ahmed, M. E.; Sauck, W.; Abouelmagd, A. A.; Chouinard, K.

    2012-12-01

    An integrated approach utilizing Very Low Frequency (VLF) and magnetic field surveying and temporal remote sensing data including: (1) Advanced Space Borne Thermal Emission and Reflection (ASTER) data, (2) European Remote Sensing (ERS-1 and ERS-2) radar imagery, and (3) Tropical Rainfall Measuring Mission (TRMM) was used to delineate water-bearing sub-vertical shear zones within the basement complex of the Sinai Peninsula. The following steps were undertaken: (1) the shear zones and dyke swarms within the basement complex were delineated using false color ASTER band and band ratio images; (2) the spatial and temporal precipitation events over the basement complex were then identified from TRMM data, and (3) finally, observations extracted from temporal radar and thermal ASTER bands were used to identify the water-bearing shear zones and dyke swarms. A fracture or dyke was deemed to be water bearing if: (1) it witnessed a large increase in its reflectivity and emissivity compared to its surroundings following a precipitation event, and maintained such differences for periods ranging from days to months. Field observations and VLF investigations were then applied to test the validity of our satellite-based methodologies for locating targeted aquifer types and for refining the satellite-based selections. The VLF detects conductive water-saturated subvertical breccia zones in bedrock. Thirty two VLF transects were collected in September of 2011 and July of 2012 along with 10 magnetic profiles at the same VLF locations. Both VLF and magnetic transects were acquired along a traverse perpendicular to the dike orientations with station separations ranging from 10 to 25 m. The VLF receiver (T-VLF) measures the distortion of the normally horizontal electromagnetic flux lines by local electrical conductors. At each VLF station, and for each frequency used, the following were measured: the tilt of the electromagnetic field, from the horizontal (given in percentage), the

  16. The petrology of the layered gabbro intrusion, eastern gabbro, Coldwell alkaline complex, Northwestern Ontario, Canada: evidence for multiple phases of intrusion in a ring dyke

    NASA Astrophysics Data System (ADS)

    Shaw, Cliff S. J.

    1997-07-01

    The Coldwell alkaline complex is a large (> 350 km 2) gabbro and syenite intrusion on the north shore of Lake Superior. It was emplaced at 1108 Ma during early magmatic activity associated with the formation of the Mid-Continent Rift of North America. The eastern gabbro forms a partial ring dyke on the outer margin of the complex and consists of at least three discrete intrusions. The largest of these is the layered gabbro that comprises a 300 m thick fine- to medium-grained basal unit overlain by up to 1100 m of variably massive to layered gabbroic cumulates which vary from olivine gabbro to anorthosite. Several xenoliths of Archaean metamorphic rocks that range in size from 10's to 100's of meters are present in the central part of the intrusion. Within discrete horizons in the layered gabbro are many centimeter- to meter-scale, gabbroic xenoliths. The main cumulus minerals, in order of crystallization, are plagioclase, olivine and clinopyroxene ± Fe-Ti oxides. Biotite and Fe-Ti-oxide are the dominant intercumulus phases. Orthopyroxene occurs not as a cumulus phase but as peritectic overgrowths on cumulus olivine. A detailed petrographic and mineral chemical study of samples from two stratigraphically controlled traverses through the layered gabbro indicates that the stratigraphy cannot be correlated along the 33 km strike of the ring dyke. Mineral compositions show both normal and reversed fractionation trends. These patterns are interpreted to record at least three separate intrusions of magma into restricted dilatant zones within the ring dyke possibly associated with ongoing caldera collapse. Calculations of parental melt composition using mineral — melt equilibria show that even the most primitive gabbros crystallized from an evolved magma with mg# of 0.42-0.49. The presence of orthopyroxene overgrowths on cumulus olivine suggests rising silica activity in the melt during crystallization and implies a subalkaline parentage for the layered gabbro.

  17. From feeder dykes to scoria cones: the tectonically controlled plumbing system of the Rauðhólar volcanic chain, Northern Volcanic Zone, Iceland

    NASA Astrophysics Data System (ADS)

    Friese, Nadine; Bense, Frithjof A.; Tanner, David C.; Gústafsson, Lúðvík E.; Siegesmund, Siegfried

    2013-06-01

    The Rauðhólar volcanic chain, located in the Northern Volcanic Zone of Iceland, has been variably eroded such that, in the northern part, the original scoria cones are preserved, while the central and southern parts expose their shallow feeders. The chain thus offers insight into the inner workings of the near-surface feeder system of scoria cones. The volcanic chain was mapped in 3D using GPS. The en echelon-arranged volcanic chain can be divided into three parts: The southernmost part contains only plugs and necks with a thin pyroclastic cover as well as multi-tiered lava flows. The central part combines partially eroded scoria cones, (feeder) dyke intersections, and welded scoria interbedded within rootless and clastogenic lava flows; the welded scoria is composed of different kinds of lithics and bombs. The northern part preserves almost intact, overlapping scoria cones with voluminous lapilli-sized scoriaceous deposits. The overall dyke trend is orthogonal but shows radial patterns in individual cone complexes. Feeder dykes observed to depths of about 200 m below the volcanic chain are up to 8 m thick and flare in to conduits in the uppermost 20-50 m. The exposed shallow plumbing system shows that magma pathways through the volcanic edifice are very complex with incremental, repeated intrusions. We interpret the arcuate shape to be the result of a local change in the orientation of the stress field because the Rauðhólar volcanic chain is located within a major relay structure between volcanoes on the eastern Fremrinámur rift arm and a rift extension with grabens on the western periphery.

  18. Analysis of the deconstruction of Dyke Marsh, George Washington Memorial Parkway, Virginia-Progression, geologic and manmade causes, and effective restoration scenarios

    USGS Publications Warehouse

    Litwin, Ronald J.; Smoot, Joseph P.; Pavich, Milan J.; Markewich, Helaine W.; Oberg, Erik; Helwig, Ben; Steury, Brent; Santucci, Vincent L.; Durika, Nancy J.; Rybicki, Nancy B.; Engelhardt, Katharina M.; Sanders, Geoffrey; Verardo, Stacey; Elmore, Andrew J.; Gilmer, Joseph

    2011-01-01

    Photoanalysis of time-sequence aerial photographs of Dyke Marsh enabled us to calculate shoreline erosion estimates for this marsh over 19 years (1987-2006), as well as to quantify overall marsh acreage for 6 calendar years spanning an ~70 year interval (1937-2006). Photo overlay of a historic map enabled us to extend our whole-marsh acreage calculations back to 1883. Both sets of analyses were part of a geologic framework study in support of current efforts by the National Park Service (NPS) to restore this urban wetland. Two time intervals were selected for our shoreline erosion analyses, based on image quality and availability: 1987 to 2002, and 2002 to 2006. The more recent time interval shows a marked increase in erosion in the southern part of Dyke Marsh, following a wave-induced breach of a small peninsula that had protected its southern shoreline. Field observations and analyses of annual aerial imagery between 1987 and 2006 revealed a progressive increase in wave-induced erosion that presently is deconstructing Hog Island Gut, the last significant tidal creek network within the Dyke Marsh. These photo analyses documented an overall average westward shoreline loss of 6.0 to 7.8 linear feet per year along the Potomac River during this 19-year time interval. Additionally, photographic evidence documented that lateral erosion now is capturing existing higher order tributaries in the Hog Island Gut. Wave-driven stream piracy is fragmenting the remaining marsh habitat, and therefore its connectivity, relatively rapidly, causing the effective mouth of the Hog Island Gut tidal network to retreat headward visibly over the past several decades. Based on our estimates of total marsh area in the Dyke Marsh derived from 1987 aerial imagery, as much as 12 percent of the central part of the marsh has eroded in the 19 year period we studied (or ~7.5 percent of the original ~78.8 acres of 1987 marshland). Shoreline loss estimates for marsh parcels north and south of our

  19. Integrated methodologies for the 3d survey and the structural monitoring of industrial archaeology: the case of the Casalecchio di Reno Dyke, Italy

    NASA Astrophysics Data System (ADS)

    Bitelli, Gabriele; Girelli, Valentina A.; Vittuari, Luca; Zanutta, Antonio

    2010-05-01

    The concept of "Industrial Archaeology" was introduced in the 1950s in England in order to consider the branch of Archaeology that, in integration with engineering, architecture and economics, studies the industrial past, with the purpose of document, protect and exploite the industrial-cultural heritage. The systematic study of this kind of structures and artefacts need a wide range approach, that starts from the investigation about the object historic fonts until its complete qualitative and quantitative description, also considering the characteristics of the surrounding territory. This task often needs the integration of different survey techniques for data capturing and processing, in order to perform the 3D modeling and to analize the structural deformations of manufactured articles. The paper presents the surveying and monitoring activities on the important structure of the Casalecchio di Reno dyke, near Bologna. The first historic notes on the dyke are very old; they are dated back to the I millenium A. D. and report the news of a wooden barrage of the Reno canal. The construction of the actual structure is in the period 1360-1367 and suffered during the centuries numerous interventions and restores. The surveying activities on the dyke were realized in 2005-2006 and 2009 and involved different techniques (classical topography, high precision geometric levelling, range-based method by terrestrial laser scanning, digital photogrammetry, thermal imagery) integrated together in a unique local reference system, in order to study the stability and the movements of the structure in a established period of time and to realize a 3D model. Together with detail surveys on the single parts of the structure, an analysis at a larger territorial scale was performed by aerial photogrammetry, either using current imagery and historical data. The topographic measurements with traditional differential techniques have achieved a very high level precision and the realized

  20. First cross-correlated measurements of magma dynamics and degassing during a dyke eruption at Piton de la Fournaise hot spot volcano, Reunion island

    NASA Astrophysics Data System (ADS)

    Allard, P.; La Spina, A.; Tamburelllo, G.; Aiuppa, A.; Coquet, A.; Brenguier, F.; Coppola, D.; Di Muro, A.; Burton, M. R.; Staudacher, T.

    2011-12-01

    Piton de la Fournaise (PdF), in the western Indian Ocean, is a very active hot spot basaltic volcano whose eruptions (1-2 per year on average) are well anticipated by the local seismic-geodetic monitoring network. Here we report on the first cross-correlated measurements of seismic tremor, magmatic gas composition (OP-FTIR absorption spectroscopy and in situ MultiGas analysis plus filter-pack sampling), gas fluxes (DOAS) and magma extrusion rate (space-borne MODIS data) during a 2-weeks long dyke eruption at PDF in October 2010. Precursory seismic signals indicated dyke ascent in a few hours from a reservoir located at ~2.5 km beneath the summit crater. After an initial burst coinciding with eruptive fissure opening, both the tremor amplitude, lava extrusion rate and SO2 flux coherently decreased during the first week of eruption. The co-emitted magmatic gases, whose composition varied slightly over time, were found to have a high water content (95-98 mol %), high SO2/HCl and low CO2/SO2, HCl/HF and Cl/Br ratios, consistent with a hydrous hot spot mantle source. By comparing gas fluxes with the magma co-extrusion rate and available melt inclusion data, we infer an essentially syn-eruptive (closed system) degassing for sulfur, chlorine and fluorine during the first half of the eruption. In contrast, additions of CO2 (previously accumulated or/and bubbling differentially) and H2O (external contribution from the hydrothermal system?) are required to explain the gas composition. Differential CO2 bubbling is supported by high frequency correlations between the CO2/HCl ratio and seismic tremor. The second part of the eruption was marked by a spectacular decoupling between re-increasing seismic tremor and declining lava extrusion, indicating a key control of tremor and eruptive activity by differential (open system) gas bubbling across the feeder dyke. This was associated with an increasing contribution of the low-frequency (1-3 Hz) spectral band to the tremor amplitude

  1. 40Ar/ 39Ar ages of mafic dykes from the Mesoproterozoic Chhattisgarh basin, Bastar craton, Central India: Implication for the origin and spatial extent of the Deccan Large Igneous Province

    NASA Astrophysics Data System (ADS)

    Rao, N. V. Chalapathi; Burgess, R.; Lehmann, B.; Mainkar, D.; Pande, S. K.; Hari, K. R.; Bodhankar, N.

    2011-08-01

    We present 40Ar/ 39Ar whole-rock ages of 63.7 ± 2.7 Ma (2σ, 92% Ar release) and 66.6 ± 2.2 Ma (2σ, 96% Ar release) for two samples of sub-surface mafic dykes intrusive into the sedimentary rocks of the Mesoproterozoic Chhattisgarh basin, Bastar craton, Central India. The obtained ages are synchronous with those of the Deccan Traps whose nearest exposures are at a distance of ~ 200 km to the west, and the recently dated diamondiferous orangeites (Group-II kimberlites) of the Mainpur area (located ~ 100 km SE within the Bastar craton). The chemical composition of the Chhattisgarh mafic dykes is indistinguishable from the chemostratigraphic horizons of the upper Deccan lavas of the Wai Subgroup (Ambenali and Poladpur Formations) and confirms them to be a part of the Deccan Large Igneous Province (LIP). The geological setting of the Deccan-age mafic dykes in the Chhattisgarh basin is analogous to that observed in other LIPs of the world such as (i) Pasco Basin of NW U.S.A, (ii) Ellisras sub-basin of southern Africa, (iii) Rift basins of New England in the NE U.S.A and (iv) the West Siberian Basin of Russia where LIP-related basalts and sills have been emplaced in distant domains from the main province. The Deccan-age of the Chhattisgarh dykes and the Mainpur orangeites permits a substantial increase of at least 8.5 × 10 4 km 2 in the spatial extent of the Deccan LIP. The temporal link at ~ 65 Ma between the Deccan Traps and (i) sub-surface mafic dykes within the Chhattisgarh basin and orangeites in the Bastar craton, (ii) Ambadongar carbonatite in western India, (iii) Salma mafic dyke in the Eastern Indian craton, (iv) Rajahmundry Traps off the eastern coast of southern India and (v) tholeiitic dykes and basalts from the Seychelles, suggests a common tectonomagmatic control, via a vast mantle plume-head of the order of 2000-2500 km. Our study has relevance to the (i) origin (plume vs non-plume) of the Deccan LIP, (ii) plumbing system for Deccan dykes and lavas in

  2. U-Pb geochronology and paleomagnetism of the Neoproterozoic St Simeon dolerite dykes, Quebec: an eastern Laurentian perspective of Ediacaran Rodinia breakup

    NASA Astrophysics Data System (ADS)

    Pisarevsky, Sergei; Murphy, Brendan; Hamilton, Mike; Söderlund, Ulf; Hodych, Joseph

    2013-04-01

    The St Simeon (SS) mafic dykes (150 km NE of Quebec City) are now dated at 548 ± 1 Ma (U-Pb; baddeleyite). This age is similar to a published LA-ICPMS zircon age of 550 ± 7 Ma for the Mt. St-Anselme (MS) basalts, which supports previous inferences of (i) a genetic relationship between them, (ii) the pene-contemporaneity of OIB-type mafic magmatism in East Laurentia and (iii) the existence of two late Ediacaran plumes that attended the final breakup of Rodinia and opening of the Iapetus Ocean and Tornquist Sea. Both the SS dykes and the MS basalts were sampled for paleomagnetic study. The paleomagnetic pole for SS is similar to the previously published pole for coeval basalts (Skinner Cove, SC) from Newfoundland. Unlike SC, the St Simeon pole represents rocks which are unambiguously coherent tectonically with the Laurentian Craton. This new pole is also coeval with high quality poles from the Winter Coast (Baltica) and provides paleomagnetic constraints on the history of the final breakup of Rodinia and opening of Eastern Iapetus and Tornquist Sea.

  3. Variations in the chemical composition of lamprophyllite-group minerals and the crystal structure of fluorine-rich barytolamprophyllite from new peralkaline dyke

    NASA Astrophysics Data System (ADS)

    Akimenko, M. I.; Aksenov, S. M.; Sorokhtina, N. V.; Kogarko, L. N.; Kononkova, N. N.; Rastsvetaeva, R. K.; Rozenberg, K. A.

    2015-11-01

    The variations in the chemical composition of lamprophyllite-group minerals from a peralkaline dyke of the Mokhnatye Roga area (Kandalaksha region, Kola Peninsula), which are crystallized during the entire period of dyke formation and form several generations, have been investigated. The early generations differ in a steadily high fluorine content, while the later ones exhibit reduced amount of fluorine, impurity elements, and sodium, with a simultaneous increase in the potassium content. The crystal structure of fluorine- rich barytolamprophyllite (potentially a new representative of the lamprophyllite group, differing by the predominance of fluorine in the anion X site) has been analyzed by single crystal X-ray diffraction. This mineral is found to have a monoclinic unit cell with the following parameters: a = 19.5219(8) Å, b = 7.0915(2) Å, c = 5.3925(2) Å, β = 96.628(3)°, and sp. gr. C2/ m. The structure is refined to R = 5.73% in the anisotropic approximation of the atomic displacement parameters using 3668 I > 2σ( I). The idealized formula ( Z = 2) is (Ba,Sr)2[Na(Na,Fe)2(Ti,Mg)F2][Ti2(Si2O7)2O2].

  4. On our need to move beyond folk medicine: A commentary on Karen Gubb's paper, "Psychosomatics today: a review of contemporary theory and practice".

    PubMed

    Gottlieb, Richard M

    2013-02-01

    In her thoughtful review and synthesis, Karen Gubb overstimates the breadth of resurgent interest among psychoanalysts in psychosomatic medicine. Such a modest revival as there has been reflects primarily the activity of a few authors and editors. Still, after several decades of inactivity following the intense excitement about this subject during the 1940s and 1950s, there has been some renewal of interest, primarily in Europe and among a small group in the United States. The golden age of psychoanalytic psychosomatics came to an end with the failure to find evidence in support of the promising but overly simplistic specificity theories, especially those of Franz Alexander. If we were going to better understand the complex relations between bodily states (including illnesses) and mental phenomena new theories and modes of investigation would be required. Many apparently new theories have been put forward over the past few decades. Of these, Gubb focuses her attention on two that relate somatic illness to failures in linguistic or symbolic elaboration, that is, to failures in the working over or binding of somatic excitations by the mental apparatus. These theories share the attractive feature that they seem consistent with the claim that psychosomatically ill patients are impaired in their language capacities, being unable to put feelings into words (alexithymia) and unable to move to abstract from concrete thinking (pensée opératoire). While apparently new, when closely examined these theories turn out to be but minor variations of one of Freud's own fundamental theories of mind/body, the one explicated in The Interpretation of Dreams and based upon the neurological model of the reflex arc as known in the 19th century. We know too much today about neuronal functioning, brain operations, and the importance of our subtle interactions with others to be satisfied with a superannuated scientific model. If we analysts are to lay claim to a science beyond a quaint

  5. Geochemistry of gabbros and basaltic dykes from the upper/lower oceanic crust boundary: New data from IODP Expedition 335 (ODP Site 1256, Cocos Plate)

    NASA Astrophysics Data System (ADS)

    Godard, M.; Adachi, Y.; Miyashita, S.; Kurz, M. D.; Roy, P.

    2012-12-01

    ODP Hole 1256D (Cocos plate), a borehole in a 15 m.y old oceanic crust formed at a superfast spreading ridge, was deepened down to 1521.6 meters below seafloor (mbsf) during IODP Expedition 335. The lower part of the borehole (>1340 mbsf) crosscuts a series of variably altered lithologies interpreted as marking the transition from upper to lower crust (top to bottom): basaltic sheeted then granoblastic dykes, a ~50 m gabbro screen (Gabbro 1), a ~20 m interval of granoblastic dykes (Dyke Screen 1), a ~20 m gabbro screen (Gabbro 2) then a second interval of granoblastic dykes. We present the results of an XRF and ICPMS study performed on 3 cored granoblastic dikes from this last interval, and on a basalt, 5 granoblastic dikes and two gabbroic rocks retrieved during junk basket runs during Expedition 335. The basalt and granoblastic dikes have MORB type compositions similar to that of the variably altered basalt samples and granoblastic dikes cored during the previous expeditions at Hole 1256D. Expedition 335 granoblastic dikes are characterized by their depletion in lithophile trace elements (Yb~2-3 ppm) similar to those of the granoblastic dikes cored below Gabbro 2, which represent the most depleted end-member of the basaltic dikes previously found at Site 1256 (Yb~2.5-6 ppm). We interpret this signature as evidence that the Expedition 335 granoblastic dikes come from the bottom of Hole 1256D (at Gabbro 2 lower interface and below) rather than from shallower levels. The two gabbros (olivine gabbronorite and olivine gabbro) have high LOI indicating that they were more affected by low temperature hydration processes than the neighboring granoblastic dikes. Their composition is similar to that of the less evolved end-members of the gabbroic rock suite previously sampled at Hole 1256D, which were found in the Gabbro 1 interval. They have relatively high Mg# (70-72) and Ni (200-280 ppm), reflecting their modal olivine content. Although they are slightly depleted

  6. Deformation monitoring of the 2014 dyke intrusion and eruption within the Bárðarbunga volcanic system, and associated stress triggering at neighbouring volcanoes

    NASA Astrophysics Data System (ADS)

    Parks, Michelle; Árnadóttir, Thóra; Dumont, Stéphanie; Sigmundsson, Freysteinn; Hooper, Andrew; Drouin, Vincent; Ófeigsson, Benedikt; María Friðriksdóttir, Hildur; Hreinsdóttir, Sigrún; Rafn Heimisson, Elías; Vogfjörd, Kristín; Jónsdóttir, Kristín; Hensch, Martin; Guðmundsson, Gunnar; Magnússon, Eyjólfur; Einarsson, Páll; Rut Hjartardóttir, Ásta; Pedersen, Rikke

    2015-04-01

    The recent unrest and activity within the Bárðarbunga volcanic system, Iceland was initially identified by the onset of an intense earthquake swarm on the 16th August 2014 and concurrent movement registered at several nearby continuous GPS (cGPS) sites. Over the following weeks additional cGPS stations were installed, campaign sites were reoccupied and interferograms formed using X-band satellite images. Data were analysed in near real-time and used to map ground displacements associated with the initial dyke emplacement and propagation (NE of Bárðarbunga), responsible for the sudden unrest. On the 29th August 2014, a small fissure opened up just a few kilometers to the north of the Vatnajökull ice cap, at Holuhraun. The eruption lasted only a few hours, but was followed on 31st August by the onset of a fissure eruption, characterised by lava fountaining and the extrusion of extensive lava flows. The eruption continues at the time of writing (January 2015). We demonstrate how Interferometric Synthetic Aperture Radar (InSAR) analysis, in conjunction with GPS measurements and earthquake seismicity, has been instrumental in the continued monitoring of Bárðarbunga volcanic system since the onset of unrest. We also investigate how changes in the local stress field induced by the dyke intrusion and concurrent magma withdrawal may trigger seismicity and potentially renewed activity at neighbouring volcanoes. InSAR analysis has systematically been used throughout the eruption to monitor co-eruptive displacement in the vicinity of both the dyke and the eruption site, along with major co-eruptive subsidence occurring beneath the Bárðarbunga caldera - the latter is believed to have commenced shortly after the onset of the unrest and is associated with magma withdrawal beneath the central volcano, feeding the dyke and the ongoing eruption. We use Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) techniques to generate a time series of

  7. Petrological, geochemical and isotopic investigations on a carbonate-dyke and enclosed pyroxenite xenoliths from Val Mastallone (Ivrea-Verbano Zone): evidence of a cumulate carbonatite in the lower crust?

    NASA Astrophysics Data System (ADS)

    Galli, Andrea; Grassi, Daniele; Burg, Jean-Pierre; Schwab, Leo; Rickli, Jörg; Gianola, Omar

    2016-04-01

    The Ivrea-Verbano Zone (Italy/Switzerland) represents one of the best exposed mantle-crust sections worldwide. Its geological evolution has been governed by the Permian underplating of mantle-derived basic magmas („Mafic Complex") into the high-grade basement of the Southern Alps. In the Ivrea-Verbano Zone, marbles occur as concordant bodies or partly discordant carbonate-dykes. Generally, these dykes are constituted of calcite, diopside, scapolite, contain enclave of the host rocks and display sharp contacts to the host lithologies without evidences of alteration zones. In Val Mastallone, an up to 40 m thick carbonate-dyke with different characteristics occurs within mafic granulites. This dyke is composed of calcite, clinopyroxene and subordinate allanite and zircon. No scapolite is observed. The contacts to the host granulites are characterized by alteration zones composed of actinolite, chlorite, clinozoisite, plagioclase and calcite. The carbonate-dyke bears enclave of phlogopite-amphibole-apatite-rutile-ilmenite ± garnet or spinel clinopyroxenites. These rock type is not outcropping elsewhere in the proximity of the dyke, suggesting a significant transport. Host mafic granulite enclave are found exclusively at the margin of the dyke. Calcite dykelets rich in zircon, baddeleyite and other Ba, U, Th, REE-rich phases cut across the enclave. The carbonate-dyke shows an enrichment of LREE over HREE ((La/Yb)N = 14), with a Σ REE = 338 and Y/Ho = 27. On the chondrite-normalized REE abundances diagram, no Eu anomaly is observed. Mantle-normalized pattern shows strong negative anomalies at Cs, Rb, K, Pb, P, Zr, Hf, Ti and positive Ba, Th, Sr, Nd anomalies, similarly to the "world average carbonatites". Measured absolute trace element concentrations are lower than average carbonatites but significantly higher than typical limestones and similar to cumulate carbonatites found elsewhere in the world (e.g. India, China, Brazil). Grt-bearing clinopyroxenite enclave

  8. In-situ Analysis of Diamonds and Their Mineral Inclusions From the Lynx Kimberlite Dyke Complex, Central Quebec

    NASA Astrophysics Data System (ADS)

    van Rythoven, A.; McCandless, T. E.; Schulze, D. J.; Bellis, A.; Taylor, L. A.; Liu, Y.

    2009-05-01

    Twenty diamonds from the 522 Ma Lynx kimberlite dyke complex were selected from 442 stones in the 1.47- 3.45mm (+3 to +11 DTC) sieve class on the basis of visible inclusions. The 442 diamonds are part of a larger population of 6598 stones produced from 34 t and 494 t bulk samples taken in 2005 and 2007, respectively. The twenty diamonds all have octahedral primary growth forms. Three macles occur, as does one example of two intergrown octahedra connected along their {111} faces. Two samples are coarse intergrowths of octahedra. Most of the diamonds display a significant degree of resorption and range from octahedra with rounded corners and edges to tetrahexahedroida. Shield and serrate laminae, and hillocks are the most common resorption-related surface features. Nineteen of the samples have light brown to brown colouration. After their external morphology was examined, the diamonds were cut and polished along a single plane to expose included mineral grains for compositional analysis and to image internal structure. Cathodoluminescence imaging reveals deformation lamellae in the majority of the diamonds. A subset of these stones show deformation lamellae truncated by growth/resorption zones and in some cases intersection of planes of different orientation. Oscillatory planar growth patterns are the most common. However, examples of simple homogeneous, complex planar, and complex undulating growth zones occur. Inclusions, particularly olivine, typically occur in core/early growth regions of the diamonds. Of the twenty diamonds, sixteen have primary inclusions. The inclusion suite is largely peridotitic. Seventeen forsteritic olivine inclusions occur in ten diamonds and have molar Mg/(Mg+Fe)= 0.916-0.933. Seven Cr-diopside inclusions occur in one diamond (2.2-2.3 wt. % Cr2O3). Four Cr-pyropes (Cr/(Cr+Al) = 0.28-0.41) occur in three diamonds. Two enstatite inclusions (Mg/(Mg+Fe) = 0.938-0.94) occur in two diamonds. One heterogeneous inclusion of monosulfide solid

  9. U-Pb (ID-TIMS) baddeleyite ages and paleomagnetism of 1.79 and 1.59 Ga tholeiitic dyke swarms, and position of the Rio de la Plata Craton within the Columbia supercontinent

    NASA Astrophysics Data System (ADS)

    Teixeira, Wilson; D'Agrella-Filho, Manoel S.; Hamilton, Mike A.; Ernst, Richard E.; Girardi, Vicente A. V.; Mazzucchelli, Maurizio; Bettencourt, Jorge S.

    2013-08-01

    The Tandilia Terrane (southernmost fringe of the Rio de la Plata Craton) is an igneous and metamorphic complex produced by an accretionary orogeny (2.25-2.02 Ga). Calc-alkaline acidic dykes with E-W strike and a major shear zone with similar orientation are related with the late orogeny stage, as supported by field relations. In a previous study the acid dykes gave 40A-39Ar ages of 2007 ± 24 Ma to 2020 ± 24 Ma. A N and NW trending tholeiitic dyke swarm (Tandil swarm) is also present in the Tandilia Terrane. One sample from the NW-trending subset previously gave a U-Pb (ID-TIMS) baddeleyite age of 1588 ± 11 Ma. New precise U-Pb (ID-TIMS) baddeleyite dating of both N- and NW-trending Tandil dykes yielded crystallization ages of 1589 ± 3 Ma, 1588 ± 3 Ma and 1588 ± 3 Ma. Significantly older tholeiitic dykes known as the Florida swarm occur in the Northern Rio de la Plata Craton, for which a U-Pb (ID-TIMS) baddeleyite age of 1790 ± 5 Ma was previously reported. Consequently intermittent rifting (1.79, 1.59 Ga) took place after tectonic stabilization of the late Paleoproterozoic lithosphere (proto-Rio de la Plata Craton). The available geochemical data for the 1.59 Ga Tandil dykes define low- and high-TiO2 trends, although, only the low-TiO2 subgroup is firmly dated. Both the Tandil and Florida dykes have geochemical and Nd-Sr characteristics consistent with derivation from heterogeneous mantle sources that underwent metasomatic effects. The Tandil dykes may be linked with the 1.57 ± 0.02 Ga Capivarita anorthosite which occurs to the east of the northern part of the craton. Correlatives on other crustal blocks may include those in Baltica such as bimodal rock association (including the Breven-Hällefors and Åland-Åboland diabase dykes) and in the reconstructed Gawler Craton/NW Laurentia dolerites, bimodal magmatism and IOCG deposits. Contemporary within-plate bimodal associations are also present in the SW Amazonian Craton. Paleomagnetic data for the 1790 Ma

  10. Estimated Flood-Inundation Mapping for the Upper Blue River, Indian Creek, and Dyke Branch in Kansas City, Missouri, 2006-08

    USGS Publications Warehouse

    Kelly, Brian P.; Huizinga, Richard J.

    2008-01-01

    In the interest of improved public safety during flooding, the U.S. Geological Survey, in cooperation with the city of Kansas City, Missouri, completed a flood-inundation study of the Blue River in Kansas City, Missouri, from the U.S. Geological Survey streamflow gage at Kenneth Road to 63rd Street, of Indian Creek from the Kansas-Missouri border to its mouth, and of Dyke Branch from the Kansas-Missouri border to its mouth, to determine the estimated extent of flood inundation at selected flood stages on the Blue River, Indian Creek, and Dyke Branch. The results of this study spatially interpolate information provided by U.S. Geological Survey gages, Kansas City Automated Local Evaluation in Real Time gages, and the National Weather Service flood-peak prediction service that comprise the Blue River flood-alert system and are a valuable tool for public officials and residents to minimize flood deaths and damage in Kansas City. To provide public access to the information presented in this report, a World Wide Web site (http://mo.water.usgs.gov/indep/kelly/blueriver) was created that displays the results of two-dimensional modeling between Hickman Mills Drive and 63rd Street, estimated flood-inundation maps for 13 flood stages, the latest gage heights, and National Weather Service stage forecasts for each forecast location within the study area. The results of a previous study of flood inundation on the Blue River from 63rd Street to the mouth also are available. In addition the full text of this report, all tables and maps are available for download (http://pubs.usgs.gov/sir/2008/5068). Thirteen flood-inundation maps were produced at 2-foot intervals for water-surface elevations from 763.8 to 787.8 feet referenced to the Blue River at the 63rd Street Automated Local Evaluation in Real Time stream gage operated by the city of Kansas City, Missouri. Each map is associated with gages at Kenneth Road, Blue Ridge Boulevard, Kansas City (at Bannister Road), U.S. Highway 71

  11. U-Pb baddeleyite ages and geochemistry of dolerite dykes in the Bas Drâa Inlier of the Anti-Atlas of Morocco: Newly identified 1380 Ma event in the West African Craton

    NASA Astrophysics Data System (ADS)

    El Bahat, Abdelhakim; Ikenne, Moha; Söderlund, Ulf; Cousens, Brian; Youbi, Nasrrddine; Ernst, Richard; Soulaimani, Abderrahmane; El Janati, M'hamed; Hafid, Ahmid

    2013-08-01

    In the Bas-Drâa Inlier (Anti-Atlas, Morocco), the Paleoproterozoic basement which is cut by the Ediacaran Taourgha granite is also crosscut by numerous dykes of a variety of trends, mostly of uncertain age. Two doleritic dykes are dated by the ID-TIMS U-Pb method on baddeleyite and yield emplacement ages of 1381 ± 8 Ma (MSWD = 0.84) and 1384 ± 6 Ma (MSWD = 1.4) determined for a N135°E and a N40°E trending dyke, respectively. These dates represent the first geochronological evidence of a Mesoproterozoic magmatic event in the Anti-Atlas. This magmatic event falls in the previously considered ca 1.7-1.0 Ga (Mesoproterozoic) gap in geological activity in the Anti-Atlas. The poorly dated Taghdout and Taarotihate sequences could represent remnants of the ca. 1380 Ma magmatism and rift-related sedimentation. The Mesoproterozoic sedimentary succession of the Atar Group in the Taoudeni basin (Mauritania) could also represent a good candidate for rift-related sedimentation but it postdates the 1380 Ma magmatic event by 270 Ma. The dated 1380 Ma dykes are transitional to mildly alkaline basalts, not unlike some Hawaiian lavas. However, these dykes have a distinct negative Nb anomaly (a common features in many Large Igneous Provinces, LIPs), and this requires interaction with the lithosphere. This interaction may have occurred at the level of the lithospheric mantle or the crust. These newly dated 1380 Ma dykes may converge to the north, speculatively suggesting a magmatic center (associated with a 1380 Ma mantle plume?) along the northern margin, and possibly linked to rifting and possible breakup on that margin, and also to a regional uplift that largely removed the evidence of a 1380 Ma cover sequence. Contemporaneous 1380-1390 Ma magmatism is reported elsewhere on other crustal blocks, and that in northeastern Laurentia (northern Greenland), northern Siberia (Anabar shield), and Baltica (southern Urals) can be reconstructed with that of the Bas Drâa Inlier (Anti

  12. Petrology of continental tholeiitic magmas forming a 350-km-long Mesozoic dyke swarm in NE Brazil: Constraints of geochemical and isotopic data

    NASA Astrophysics Data System (ADS)

    Ngonge, Emmanuel Donald; de Hollanda, Maria Helena Bezerra Maia; Archanjo, Carlos José; de Oliveira, Diógenes Custódio; Vasconcelos, Paulo Marcosde Paula; Muñoz, Patrício Rodrigo Montecinos

    2016-08-01

    The Ceará Mirim dyke swarm (northeastern Brazil) is composed of Cretaceous tholeiites with plagioclase, clinopyroxene (± olivine), Fe-Ti oxides and pigeonite in their groundmass. These tholeiites have been subdivided into three groups: high-Ti olivine tholeiites, evolved high-Ti tholeiites (TiO2 ≥ 1.5 wt.%; Ti/Y > 360), and low-Ti tholeiites (TiO2 ≤ 1.5 wt%; Ti/Y ≤ 360), with all exhibiting distinct degrees of enrichment in incompatible elements relative to Primitive Mantle. Negative Pb anomalies are found in all three groups, while Nb-Ta abundances similar to those of OIB-type magmas are found in the olivine tholeiites, with moderate to high depletions being observed, respectively, in the evolved high-Ti and low-Ti tholeiites. The low-Ti tholeiites exhibit some contamination with crustal (felsic) materials during ascent. The initial isotopic compositions of the olivine tholeiites show uniform and unradiogenic 87Sr/86Sr (~ 0.7035-0.7039) combined with (in part) radiogenic 143Nd/144Nd and 206Pb/204Pb (> 19.1) ratios, which together reveal a likely contribution of FOZO (FOcalZOne) component in their genesis. The other tholeiite groups show variable Sr-Nd ratios with relatively consistent 206Pb/204Pb ratios clustering towards an isotopically enriched mantle (EM1) component. Taken in conjunction with the Nb, this enriched signature reflects the involvement of a subduction-modified lithospheric mantle in the source of the evolved high-Ti and low-Ti tholeiites. Thus, we propose that FOZO and EMI components coexisted (including minor mixing with E-MORB magmas) and contributed in varying extents to the generation of the Ceará-Mirim dyke swarm primary melts, which segregated at 75 to 60 km in depth around the garnet-spinel facies transition zone. The mechanism that promoted melting was most likely non-plume related. We suggest that plate-boundary forces linked to the opening of the Atlantic Ocean promoted passive rifting and that the resulting asthenospheric

  13. Petrology, 40Ar/39Ar age, Sr-Nd isotope systematics, and geodynamic significance of an ultrapotassic (lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton, India

    NASA Astrophysics Data System (ADS)

    Rao, N. V. Chalapathi; Atiullah; Burgess, R.; Nanda, Purnendu; Choudhary, A. K.; Sahoo, Samarendra; Lehmann, B.; Chahong, Ngazipmi

    2016-04-01

    We report the mineralogy, bulk-rock geochemistry, 40Ar/39Ar (whole-rock) age and radiogenic (Sr and Nd) isotope composition of an ultrapotassic dyke from Sakri (Nuapada lamproite field) located at the tectonic contact between the easternmost margin of the Bastar craton and Eastern Ghats Mobile Belt, India. The Sakri dyke has a mineralogy which strongly resembles a lamproite sensu stricto (viz.,Ti-rich phlogopite, Na-poor diopside, Fe-rich sanidine, ulvospinel trend and Sr-rich apatite). However, its bulk-rock major element geochemical characteristics (viz., extreme silica-undersaturated nature) resemble sensu lato kamafugite from Toro Ankole, Uganda, East African Rift, and Alto Paranaiba Province, Brazil. The Sakri dyke also displays certain compositional peculiarities (viz., high degree of evolution of mica composition from phlogopite to biotite, elevated titanium and aluminum in clinopyroxene and significantly lower bulk Mg#) when compared to the ultrapotassic rocks from various Indian cratons. 40Ar/39Ar dating gave a plateau age of 1045 ± 9 Ma which is broadly similar to that of other Mesoproterozoic (i) lamproites from the Bastar and Bundelkhand cratons, and (ii) kimberlites from the Eastern Dharwar craton. Initial bulk-rock Sr (0.705865-0.709024) and Nd (0.511063-0.511154) isotopic ratios reveal involvement of an `enriched' source region with long-term incompatible element enrichment and a depleted mantle (TDM) Nd model age of 2.56 Ga straddling the Archaean-Proterozoic chronostratigraphic boundary. The bulk-rock incompatible trace element ratios (Ta/Yb, Th/Yb, Rb/Ba and Ce/Y) of the Sakri ultrapotassic dyke negate any significant influence of crustal contamination. Small-degree melting (1 to 1.5 %) of a mixed garnet-facies and spinel-facies phlogopite lherzolite can account for its observed REE concentrations. Whereas the emplacement of the Sakri ultrapotassic dyke is related to the amalgamation of the supercontinent of Rodinia, its overlapping geochemical

  14. Reply to Comment on "U-Pb baddeleyite ages and geochemistry of dolerite dykes in the Bas-Drâa inlier of the Anti-Atlas of Morocco: Newly identified 1380 Ma event in the West African Craton" by André Michard and Dominique Gasquet

    NASA Astrophysics Data System (ADS)

    Söderlund, Ulf; Ibanez-Mejia, Mauricio; El Bahat, Abdelhakim; Ernst, Richard E.; Ikenne, Moha; Soulaimani, Abderrahmane; Youbi, Nasrrddine; Cousens, Brian; El Janati, M'hamed; Hafid, Ahmid

    2013-08-01

    Baddeleyite (ZrO2) is today recognized as the key mineral for dating the emplacement of mantle-derived igneous rocks, primarily gabbro and dolerite dykes and sills. The comment by Michard and Gasquet calls for a discussion on the significance of baddeleyite U-Pb TIMS dates of two dykes in the Bas-Drâa inlier, dated at 1381 ± 8 and 1384 ± 6 Ma, presented in El Bahat et al. (2013-in this issue). They suggest that the U-Pb systematics were "seriously perturbed in the Bas-Drâa region" with the main argument being a lack of age matches between the ca. 1385 Ma dykes in Bas-Drâa and the 2040, 1650 and 885 Ma dykes in adjacent inliers to the east. To infer an older age for these dykes, as suggested by Michard and Gasquet, and explain the ca. 1385 Ma TIMS results would require two separate events of perturbation, in the Mesoproterozoic and a subsequent Variscan event. However, such an alternative is improbable from basic theoretical reasoning using U-Pb isotopic systematics and our current understanding of the behaviour of baddeleyite in metamorphic systems. In addition, we present new LA-ICPMS U-Pb age data of baddeleyite from one of the dated dykes from Bas-Drâa. The new LA-ICPMS U-Pb age of 1416 ± 7 Ma is slightly but significantly older than our TIMS 1384 ± 6 Ma upper intercept age, nevertheless confirming this dyke could not correspond to any of the other mafic intrusions dated in the inliers to the east. The LA-ICPMS result also contributes to a deeper understanding on the effects of secondary processes in baddeleyite in general, and suggests a modified methodological approach for samples with complex geological histories.

  15. Regularities of spatial association of major endogenous uranium deposits and kimberlitic dykes in the uranium ore regions of the Ukrainian Shield

    NASA Astrophysics Data System (ADS)

    Kalashnyk, Anna

    2015-04-01

    During exploration works we discovered the spatial association and proximity time formation of kimberlite dykes (ages are 1,815 and 1,900 Ga for phlogopite) and major industrial uranium deposits in carbonate-sodium metasomatites (age of the main uranium ore of an albititic formation is 1,85-1,70 Ga according to U-Pb method) in Kirovogradsky, Krivorozhsky and Alekseevsko-Lysogorskiy uranium ore regions of the Ukrainian Shield (UkrSh) [1]. In kimberlites of Kirovogradsky ore region uranium content reaches 18-20 g/t. Carbon dioxide is a major component in the formation of hydrothermal uranium deposits and the formation of the sodium in the process of generating the spectrum of alkaline ultrabasic magmas in the range from picritic to kimberlite and this is the connection between these disparate geochemical processes. For industrial uranium deposits in carbonate-sodium metasomatitics of the Kirovogradsky and Krivorozhsky uranium ore regions are characteristic of uranyl carbonate introduction of uranium, which causes correlation between CO2 content and U in range of "poor - ordinary - rich" uranium ore. In productive areas of uranium-ore fields of the Kirovogradsky ore region for phlogopite-carbonate veinlets of uranium ore albitites deep δ13C values (from -7.9 to -6.9o/oo) are characteristic. Isotope-geochemical investigation of albitites from Novokonstantynovskoe, Dokuchaevskoe, Partyzanskoe uranium deposits allowed obtaining direct evidence of the involvement of mantle material during formation of uranium albitites in Kirovogradsky ore region [2]. Petrological characteristics of kimberlites from uranium ore regions of the UkrSh (presence of nodules of dunite and harzburgite garnet in kimberlites, diamonds of peridotite paragenesis, chemical composition of indicator minerals of kimberlite, in particular Gruzskoy areas pyropes (Cr2O3 = 6,1-7,1%, MgO = 19,33-20,01%, CaO = 4,14-4,38 %, the content of knorringite component of most grains > 50mol%), chromites (Cr2O3 = 45

  16. Textural, mineralogical and stable isotope studies of hydrothermal alteration in the main sulfide zone of the Great Dyke, Zimbabwe and the precious metals zone of the Sonju Lake Intrusion, Minnesota, USA

    USGS Publications Warehouse

    Li, C.; Ripley, E.M.; Oberthur, T.; Miller, J.D., Jr.; Joslin, G.D.

    2008-01-01

    Stratigraphic offsets in the peak concentrations of platinum-group elements (PGE) and base-metal sulfides in the main sulfide zone of the Great Dyke and the precious metals zone of the Sonju Lake Intrusion have, in part, been attributed to the interaction between magmatic PGE-bearing base-metal sulfide assemblages and hydrothermal fluids. In this paper, we provide mineralogical and textural evidence that indicates alteration of base-metal sulfides and mobilization of metals and S during hydrothermal alteration in both mineralized intrusions. Stable isotopic data suggest that the fluids involved in the alteration were of magmatic origin in the Great Dyke but that a meteoric water component was involved in the alteration of the Sonju Lake Intrusion. The strong spatial association of platinum-group minerals, principally Pt and Pd sulfides, arsenides, and tellurides, with base-metal sulfide assemblages in the main sulfide zone of the Great Dyke is consistent with residual enrichment of Pt and Pd during hydrothermal alteration. However, such an interpretation is more tenuous for the precious metals zone of the Sonju Lake Intrusion where important Pt and Pd arsenides and antimonides occur as inclusions within individual plagioclase crystals and within alteration assemblages that are free of base-metal sulfides. Our observations suggest that Pt and Pd tellurides, antimonides, and arsenides may form during both magmatic crystallization and subsolidus hydrothermal alteration. Experimental studies of magmatic crystallization and hydrothermal transport/deposition in systems involving arsenides, tellurides, antimonides, and base metal sulfides are needed to better understand the relative importance of magmatic and hydrothermal processes in controlling the distribution of PGE in mineralized layered intrusions of this type. ?? Springer-Verlag 2007.

  17. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations.

    PubMed

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T-C; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators. PMID:27131699

  18. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T.-C.; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators.

  19. High initiation and long duration of breastfeeding despite absence of early skin-to-skin contact in Karen refugees on the Thai-Myanmar border: a mixed methods study

    PubMed Central

    2012-01-01

    Background Early skin-to-skin contact (SSC) after birth is recommended as part of the United Nations Children’s Fund (UNICEF) baby friendly health initiative to promote optimum breastfeeding. This paper reports rates of breastfeeding initiation and duration in a low resource environment, where early SSC is not practised, and explores views of pregnant women and midwives surrounding breastfeeding and swaddling. Methods Data from records from a single hospital on the Thai-Myanmar border where refugee women gave birth during a one-year period (2010) were used to determine breastfeeding initiation rates and the time of the first breastfeed, and duration of breastfeeding of the previous alive child in multigravidae. Focus group discussions (FGD) were conducted to obtain information from pregnant women attending antenatal care about their intended or previous duration of breastfeeding and views on breastfeeding. Interviews with local midwives explored reasons for high rates of breastfeeding in this setting and the practice of newborn swaddling. Results Of 1404 live births in 2010 in Maela refugee camp there were 982 evaluable mother-newborn pairs, including 80 infants born before 37 weeks gestation. Initiation of breastfeeding within the first hour after birth and exclusive breastfeeding at discharge in term mother-newborn pairs was 91.2% (823/902) and 99.3% (896/902); and before 37 weeks gestation, 48.8% (39/80) and 98.8% (79/80). Reported duration of previous breastfeeding was 19 (range 2 to 72) months. During FGD all primigravidae (n = 17) intended to breastfeed and all multigravidae (n = 33) had previously breastfed; expected or previous duration of feeding was for more than one year or longer. The major theme identified during FGD was breastfeeding is “good”. Women stated their intention to breastfeed with certainty. This certainty was echoed during the interviews with midwifery staff. SSC requires a delay in early swaddling that in Karen people, with

  20. Obituary: Lynne Karen Deutsch, 1954-2004

    NASA Astrophysics Data System (ADS)

    Sprague, Ann L.

    2004-12-01

    It is with deep sadness and regret that we note the passing of our dear friend and colleague Prof. Lynne K. Deutsch. Lynne died on 2 April 2004 after a protracted illness and lengthy battle with complications caused by the blood disease Polycythaemia Vera. Lynne was born in Chicago on 26 November 1956 to Victor and Ailsa Deutsch. She lived with her family in the town of Morton Grove, IL until she was 8 years old, when they moved to Beverly Hills, CA. She was an outgoing child who played basketball and excelled in her studies. She graduated from Beverly Hills High School at the age of 16 after completing all high school requirements in only three years. Lynne had a beautiful singing voice, and was in the chorus in high school and college. Lynne earned her first bachelor's degree in philosophy from the University of California at Berkeley in 1977. She then returned to Berkeley and received a second bachelor's degree, this time in physics, in 1981. She was a graduate student and teaching assistant at MIT and earned an MS in physics from MIT in 1983. Lynne then attended the astronomy graduate program at Harvard University, where she earned her MA in 1985 and PhD in 1990. During her degree studies she began crafting mid-infrared instrumentation. These instruments were destined to be used by a host of eager observers to discover, identify, and study many emissions from the Solar System, and galactic and extragalactic sources. Lynne was a National Research Council Post-doctoral Fellow at NASA Ames Research Center from 1990 - 1992, where she played an important role in the development of the Smithsonian Astrophysical Observatory/University of Arizona Mid-Infrared Array Camera (MIRAC), a well-known and much sought after instrument frequently used in studies of Mercury, Jupiter, the Moon, planetary nebulae, star formation regions, galactic center, young stellar objects, and extragalactic objects. After leaving NASA Ames Research Center, Lynne taught for several years (1993-96) at Smith College where she had a significant impact on undergraduate research, especially for women, whom she enjoyed mentoring. Lynne joined the faculty in the Astronomy Department of Boston University in 1996 where she taught instrumentation principles and techniques to undergraduate and graduate students. Over the course of her faculty career, she received numerous research grants and fellowships that were used to support her research, her students, and her postdoctoral associates. She was the principal investigator of Boston University's advanced technologies and instrumentation program MIRABU: A Mid-Infrared Array. As her health declined and the rigors of a full teaching schedule became unacceptably taxing, Lynne took a leave of absence from Boston University and returned to Harvard University and the Center for Astrophysics in 2001. There she became a very active member of the Infrared Group in the OIR Division and a member of the IRAC/Spitzer Space Telescope team. Her research in infrared astronomy covered many areas including star formation, planetary and protoplanetary nebulae, solar system objects, the interstellar medium and infrared-luminous galaxies. Her most recent research with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope concentrated on high-mass star formation and the related evolution of the interstellar medium. In her short life, Lynne made many devoted friends and colleagues and was active in encouraging school-age girls to pursue their interests in the sciences. In her short career, she published more than seventy-five articles. She was an outstanding observer and instrumentalist, whose promising career was tragically cut short. Lynne was also a devoted mother and wife, and, while still well, she found the time to be an active participant in her son's elementary school. She is very greatly missed by her family. She is survived by her husband Douglas Sondak, PhD and her son Reed Deutsch-Sondak who live in Acton, MA, and her parents and sister Judith who reside in California. Lynne will be forever missed by her family, friends, colleagues, and the astronomical community. Her contributions will continue to benefit the community for many years to come. We only wish she were here to share them with us. She will be remembered as a dear friend, colleague, accomplished scientist, and dedicated family member.

  1. Obituary: Lynne Karen Deutsch, 1954-2004

    NASA Astrophysics Data System (ADS)

    Sprague, Ann L.

    2004-12-01

    It is with deep sadness and regret that we note the passing of our dear friend and colleague Prof. Lynne K. Deutsch. Lynne died on 2 April 2004 after a protracted illness and lengthy battle with complications caused by the blood disease Polycythaemia Vera. Lynne was born in Chicago on 26 November 1956 to Victor and Ailsa Deutsch. She lived with her family in the town of Morton Grove, IL until she was 8 years old, when they moved to Beverly Hills, CA. She was an outgoing child who played basketball and excelled in her studies. She graduated from Beverly Hills High School at the age of 16 after completing all high school requirements in only three years. Lynne had a beautiful singing voice, and was in the chorus in high school and college. Lynne earned her first bachelor's degree in philosophy from the University of California at Berkeley in 1977. She then returned to Berkeley and received a second bachelor's degree, this time in physics, in 1981. She was a graduate student and teaching assistant at MIT and earned an MS in physics from MIT in 1983. Lynne then attended the astronomy graduate program at Harvard University, where she earned her MA in 1985 and PhD in 1990. During her degree studies she began crafting mid-infrared instrumentation. These instruments were destined to be used by a host of eager observers to discover, identify, and study many emissions from the Solar System, and galactic and extragalactic sources. Lynne was a National Research Council Post-doctoral Fellow at NASA Ames Research Center from 1990 - 1992, where she played an important role in the development of the Smithsonian Astrophysical Observatory/University of Arizona Mid-Infrared Array Camera (MIRAC), a well-known and much sought after instrument frequently used in studies of Mercury, Jupiter, the Moon, planetary nebulae, star formation regions, galactic center, young stellar objects, and extragalactic objects. After leaving NASA Ames Research Center, Lynne taught for several years (1993-96) at Smith College where she had a significant impact on undergraduate research, especially for women, whom she enjoyed mentoring. Lynne joined the faculty in the Astronomy Department of Boston University in 1996 where she taught instrumentation principles and techniques to undergraduate and graduate students. Over the course of her faculty career, she received numerous research grants and fellowships that were used to support her research, her students, and her postdoctoral associates. She was the principal investigator of Boston University's advanced technologies and instrumentation program MIRABU: A Mid-Infrared Array. As her health declined and the rigors of a full teaching schedule became unacceptably taxing, Lynne took a leave of absence from Boston University and returned to Harvard University and the Center for Astrophysics in 2001. There she became a very active member of the Infrared Group in the OIR Division and a member of the IRAC/Spitzer Space Telescope team. Her research in infrared astronomy covered many areas including star formation, planetary and protoplanetary nebulae, solar system objects, the interstellar medium and infrared-luminous galaxies. Her most recent research with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope concentrated on high-mass star formation and the related evolution of the interstellar medium. In her short life, Lynne made many devoted friends and colleagues and was active in encouraging school-age girls to pursue their interests in the sciences. In her short career, she published more than seventy-five articles. She was an outstanding observer and instrumentalist, whose promising career was tragically cut short. Lynne was also a devoted mother and wife, and, while still well, she found the time to be an active participant in her son's elementary school. She is very greatly missed by her family. She is survived by her husband Douglas Sondak, PhD and her son Reed Deutsch-Sondak who live in Acton, MA, and her parents and sister Judith who reside in California. Lynne will be forever missed by her family, f

  2. Cumulates, Dykes and Pressure Solution in the Ice-Salt Mantle of Europa: Geological Consequences of Pressure Dependent Liquid Compositions and Volume Changes During Ice-Salt Melting Reactions.

    NASA Astrophysics Data System (ADS)

    Day, S.; Asphaug, E.; Bruesch, L.

    2002-12-01

    Water-salt analogue experiments used to investigate cumulate processes in silicate magmas, along with observations of sea ice and ice shelf behaviour, indicate that crystal-melt separation in water-salt systems is a rapid and efficient process even on scales of millimetres and minutes. Squeezing-out of residual melts by matrix compaction is also predicted to be rapid on geological timescales. We predict that the ice-salt mantle of Europa is likely to be strongly stratified, with a layered structure predictable from density and phase relationships between ice polymorphs, aqueous saline solutions and crystalline salts such as hydrated magnesium sulphates (determined experimentally by, inter alia, Hogenboom et al). A surface layer of water ice flotation cumulate will be separated from denser salt cumulates by a cotectic horizon. This cotectic horizon will be both the site of subsequent lowest-temperature melting and a level of neutral buoyancy for the saline melts produced. Initial melting will be in a narrow depth range owing to increasing melting temperature with decreasing pressure: the phase relations argue against direct melt-though to the surface unless vesiculation occurs. Overpressuring of dense melts due to volume expansion on cotectic melting is predicted to lead to lateral dyke emplacement and extension above the dyke tips. Once the liquid leaves the cotectic, melting of water ice will involve negative volume change. Impact-generated melts will drain downwards through the fractured zones beneath crater floors. A feature in the complex crater Mannan'an, with elliptical ring fractures around a conical depression with a central pit, bears a close resemblance to Icelandic glacier collapse cauldrons produced by subglacial eruptions. Other structures resembling Icelandic cauldrons occur along Europan banded structures, while resurgence of ice rubble within collapse structures may produce certain types of chaos region. More general contraction of the ice mantle

  3. Le magmatisme basique filonien néoprotérozoïque de la boutonnière de Zenaga, Anti-Atlas central, Maroc: pétrologie, géochimie et signification géodynamiqueNeoproterozoic basic dykes of the Zenaga Inlier, central Anti-Atlas, Morocco: petrology, geochemistry and geodynamic significance

    NASA Astrophysics Data System (ADS)

    Hafid, A.; Sagon, J. P.; Julivert, M.; Arboleya, M. L.; Saquaque, A.; El-Boukhari, A.; Saidi, A.; Soler, J. M. F.

    2001-05-01

    Before the Pan-African Orogeny, the Palæoproterozoic basement and its Neoproterozoic cover (limestones and quartzites) of the Zenaga Inlier were cross-cut by a swarm of doleritic dykes. They are more or less altered. The primary mineral assemblage consists of plagioclase, clinopyroxene, very rare orthopyroxene, ilmenite, apatite, micropegmatite and sometimes hornblende and biotite. Mineralogical and geochemical studies indicate that the dolerites are continental tholeiites. Two groups of dykes have been distinguished. Accordingly, rare earth elements, P 2O 5, Zr, Th, Ba and Sr contents are higher in group I than in group II, which is richer in V. Group I comprises the north-south and northwest-southeast swarms, while group II corresponds to northeast-southwest and east-west swarms, which were emplaced later. These geochemical variations may be explained by a higher degree of melting of the mantle source for the later group II. Doleritic dykes of Zenaga had been emplaced during an extensional episode, prior to Pan-African folding.

  4. Health and Human Rights in Karen State, Eastern Myanmar

    PubMed Central

    Davis, William W.; Mullany, Luke C.; Shwe Oo, Eh Kalu; Richards, Adam K.; Iacopino, Vincent; Beyrer, Chris

    2015-01-01

    Background Decades of conflict in eastern Myanmar have resulted in high prevalence of human rights violations and poor health outcomes. While recent ceasefire agreements have reduced conflict in this area, it is unknown whether this has resulted in concomitant reductions in human rights violations. Methods and Findings We conducted a two-stage cluster survey of 686 households in eastern Myanmar to assess health status, access to healthcare, food security, exposure to human rights violations and identification of alleged perpetrators over the 12 months prior to January 2012, a period of near-absence of conflict in this region. Household hunger (FANTA-2 scale) was moderate/high in 91 (13.2%) households, while the proportion of households reporting food shortages in each month of 2011 ranged from 19.9% in December to 47.0% in September, with food insecurity peaking just prior to the harvest. Diarrhea prevalence in children was 14.2% and in everyone it was 5.8%. Forced labor was the most common human rights violation (185 households, 24.9%), and 210 households (30.6%) reported experiencing one or more human rights violations in 2011. Multiple logistic regression analysis identified associations between human rights violations and poor health outcomes. Conclusion Human rights violations and their health consequences persist despite reduced intensity of conflict in eastern Myanmar. Ceasefire agreements should include language that protects human rights, and reconciliation efforts should address the health consequences of decades of human rights violations. PMID:26308850

  5. CEO evaluation--fairness above all. Interview by Karen Gardner.

    PubMed

    Moses, R

    1990-12-01

    How effectively the hospital governing board communicates with and evaluates its CEO may have a direct impact on CEO turnover. Board chairman Richard Moses of Tuomey Hospital, Sumter, SC, describes the process for conducting a fair and meaningful evaluation. PMID:10108137

  6. CERT tribal internship program. Final intern report: Karen Sandoval, 1996

    SciTech Connect

    1998-09-01

    This intern report consists of the workshop handbook for the Comprehensive Environmental and Natural Resource Management Planning workshop presented by the Council of Energy Resource Tribes. The workshop objectives were to foster and awareness of integrated resource management rationale; present the fundamental elements of an integrated approach; explain what distinguishes this approach from mainstream strategies; discuss how worldview and philosophy shape action and policy; present ways in which philosophical dexterity promotes effective management; and identify opportunities to engage and participate in integrated management. Resource articles presented at the meeting have been removed for separate processing for inclusion on the data base.

  7. CERT tribal internship program. Final intern report: Karen Sandoval, 1994

    SciTech Connect

    1998-09-01

    The purpose of the project was to: create a working relationship between CERT and Colorado State University (CSU); involve and create relationships among individuals and departments at CSU; empower Native communities to run their own affairs; establish programs for the benefit of Tribes; and create Native American Program Development Office at CSU. The intern lists the following as the project results: revised a Native American Program Development document; confirmation from 45 departments across campus for Summit attendance [Tribal Human Resource Development Summit]; created initial invitee list from CSU departments and colleges; and informed CERT and CSU staff of results. Much of the response from the campus community has been positive and enthusiastic. They are ready to develop new Native American programs on campus, but need the awareness of what they can do to be respectful of Tribal needs.

  8. Kenny and Karen Career in Hospitality and Recreation Land.

    ERIC Educational Resources Information Center

    Lyons, Lynn

    This booklet is part of a series of activity booklets designed to increase the child's awareness of careers. It also provides reinforcement activities of the basic skills. In this particular booklet children in grades K-2 are introduced to careers in the field of hospitality and recreation. The subjects of the teaching sections are children's…

  9. Mafic dykes intrusive into Pre-Cambrian rocks of the São Luís cratonic fragment and Gurupi Belt (Parnaíba Province), north-northeastern Brazil: Geochemistry, Sr-Nd-Pb-O isotopes, 40Ar/39Ar geochronology, and relationships to CAMP magmatism

    NASA Astrophysics Data System (ADS)

    Klein, Evandro L.; Angélica, Rômulo S.; Harris, Chris; Jourdan, Fred; Babinski, Marly

    2013-07-01

    Dykes of diabase and microgabbro intruded into Pre-Cambrian rocks of the São Luís cratonic fragment and Gurupi Belt, which are tectonic and erosive windows of the Parnaíba Basin in north-northeastern Brazil. Ar-Ar ages were determined, and major, trace element, and Nd-Sr-Pb-O isotopic compositions of these dykes were measured to provide insights into their age, and into the nature of their mantle sources and petrogenetic processes. The data have also been used to compare the chemical and isotopic signatures of the dykes with those of the Central Atlantic Magmatic Province (CAMP). Four chemical groups of mafic dykes have been identified. These comprise two subtypes of high-Ti rocks (i) HTi-1 (TiO2 < 2.3 wt.%; SiO2 > 47 wt.%), (ii) HTi-2 (TiO2 > 2.7 wt.%; SiO2 > 47 wt.%), in addition to (iii) evolved high-Ti (TiO2 > 4 wt.%; SiO2 of ~ 46 wt.%) and (iv) low-Si (TiO2 > 2.2 wt.%; SiO2 < 45 wt.%) rocks. 40Ar/39Ar geochronology of plagioclase returned ages of 201 ± 4 Ma and 193 ± 10 Ma for the HTi-2 subtype, and of 201 ± 2 Ma and 207 ± 9 Ma for the evolved high-Ti group. The HTi-1 and low-Si groups presented highly disturbed age spectra, and did not allow the definition of their emplacement ages. The Argon data indicate an age > 200 Ma for the low-Si group and are dubious with respect to the age of theHTi-1 subtype, if coeval with (i.e., ~ 200 Ma), or older than, the HTi-2 and evolved high-Ti types. All groups present δ18O values of pyroxene that are compatible with uncontaminated mantle-derived magmas. The HTi-1 subtype (average 143Nd/144Nd200 = 0.512644; 87Sr/86Sr200 = 0.7035; 206Pb/204Pb of 17.86) shows the less enriched and less fractionated (more primitive) trace element distribution of all groups. The HTi-2 subtype shows enriched trace element pattern and depleted Nd-Sr signature (143Nd/144Nd200 = 0.512610; 87Sr/86Sr200 = 0.7037) and average 206Pb/204Pb ratios of 17.23. The evolved high-Ti chemical group shows average ratios of 143Nd/144Nd200 = 0.512558, 87Sr

  10. "Why's a Nice Dyke like You Embracing This Postmodern Crap?"

    ERIC Educational Resources Information Center

    Lugg, Catherine A.

    2008-01-01

    In this article, I present a historical overview of the queer rights movement in the United States, from the late 1940s to today, weaving snapshots of my own life into the narrative, from living in the closet to being totally out, both personally and professionally. Because I was closeted at the beginning of my career, my research agenda did not…

  11. Dyke-Davidoff-Masson Syndrome: Time to Revisit Case Series.

    PubMed

    Shubhakaran; Bhushan, Bharat

    2015-09-01

    We read a case report by Manghera et al (JAPI, Vol 62 page No. 76-67), which was in response to an earlier case report by Ola et al.1 Here we would like to share our experience and views as under- The authors in the correspondence have said that crossed cerebellar atrophy is an unusual and rare finding. We in our study of 28 patients of DDMS, have found cerebellar atrophy in nine patients along with cerebral atrophy.2 Out of nine patients with cerebellar atrophy three patients had diffuse bilateral atrophy, only one patient had unilateral cerebellar atrophy which was controlateral to left cerebral hemiatrophy (CHA). This is similar to the findings of the authors and the patho-physiology quoted by authors is worth appreciation. Other parenchymal changes observed in our study were cerebral peduncle atrophy in three patients, and thalamic atrophy with lentiform nucleus hypoplasia in 11 patients. Seven cases of CHA were associated with ipsilateral large schizencephalic cleft with absence of the septum pellucidum whereas two had porencephaly. Five patients had left-sided hippocampal sclerosis (HS), four were concordant and one was discordant. PMID:27608884

  12. Dykes and tykes: a virtual lesbian parenting community.

    PubMed

    Lev, Arlene Istar; Dean, Gwendolyn; DeFilippis, Lauren; Evernham, Kim; McLaughlin, Larin; Phillips, Cynthia

    2005-01-01

    This article is a collaborative project by six members of an Internet community of lesbian mothers called MOMS. MOMS is a diverse community of lesbian mothers that is inclusive of bisexual and transgender women, as well those planning to become parents. The article outlines the history of the group and how the moderators have created an environment that encourages diversity. Members of the MOMS community differ in age, race, ethnicity, and nationality, as well as political, religious, and social expressions. Additionally, they became parents in diverse ways and parent children in distinct and often disparate styles. Nonetheless, MOMS is a high-volume list with a large membership that remains a close-knit and intimate discussion group. This article outlines some of the discussion topics common on the MOMS list. Some of these are particular to parenting, and others involve a broad spectrum of subjects including racism, butch/femme dynamics, vegetarianism, circumcision, breast versus bottle feeding, and transgender politics. To subscribe to the MOMS list, send an e-mail message to majordomo@groups.queernet.org. Write "subscribe moms" in the body of the e-mail, without quotation marks. PMID:19780267

  13. Imaging Dyke-Induced Deformation in the Lab

    NASA Astrophysics Data System (ADS)

    Ellwood, H.; Rivalta, E.; Wright, T. J.; O'Shea, K.; Hogg, D. C.; Boyle, R. D.

    2008-12-01

    The presence of a dike in Earth's crust can be inferred from a combination of seismological and geodetic techniques. Often, geodetic measurements (e.g. GPS and InSAR) of surface deformation near a dike are inverted for dike parameters using the equations for rectangular tensile dislocations in an elastic, homogeneous half-space, as presented in Okada (1985). Here, we create artificial dikes in the lab and simulate surface geodetic observations. Because the dike parameters are known, or can be directly observed, we are able to test the validity of standard geodetic models for dike injections. A fluid injection into gelatin is analogous to dike ascent driven by magma buoyancy in the crust; gelatin is an elastic medium (Menand and Tait, 2002) and away from the tip of a magma dike, strains are small, suggesting that deformation of the host rock may also be largely elastic (Delaney and Pollard, 1981). Gelatin has been used in several investigations into the propagation of fluid-filled cracks in the Earth's crust, including the shape and velocity of fluid-filled fractures (Takada, 1990; Dahm, 2000), propagation in layered media (Rivalta et al., 2005) and laccolith growth (Johnson and Pollard, 1973), among others. This study focuses on the deformation at the surface caused by this propagation. We seeded the upper surface of a homogeneous gelatin mass with markers and injected some fluid at the bottom of the gelatin container. We recorded the ascent of the resulting buoyancy-driven fluid-filled fracture from above with two camcorders and from the side with an additional camcorder. Surfaces markers were observed by the camcorders and tracked from one frame to the next. 3D positions were determined using photogrammetry after matching the markers. The resultant time series of surface deformation at each marker are analogous to continuous GPS observations from real dikes. The horizontal accuracy obtainable with HD camcorders was about 0.1 mm. We inverted the surface deformation using the standard Okada model, and a more realistic model based on fluid-filled fractures theory, and compared the inversion results to the direct measurements of dike parameters. We find that the Okada model underestimated the size of the dike, but overestimated the dike thickness. The parameters recovered assuming a propagating fluid-filled fracture shape were in much better agreement with the real observations.

  14. Freud, females, childbirth, and dissidence: Margarete Hilferding, Karen Horney, and Otto Rank.

    PubMed

    Balsam, Rosemary

    2013-10-01

    These three early psychoanalysts, who differed in important ways from Freud, each tried to shift his fundamental beliefs about women's bodies in basic developmental theory. This paper illustrates this point by elaborating their materials concerning the centrality of childbirth. One thematic aspect of Freud's disruptive fights with colleagues lay in his loyalty to phallocratic certainties. These problems still affect us, a century later, even in today's clinically pluralistic climate. PMID:24063270

  15. Concept Teaching in Movement and Music. Profiles/Tommie Bowling and Karen Delgado.

    ERIC Educational Resources Information Center

    Werner, Peter H.

    1982-01-01

    In a South Carolina elementary school, the music teacher and physical education teacher, working together, have developed a curriculum to reinforce and complement learning of concepts common to both areas. Concepts such as space, force (dynamics), time, flow, rhythm, and pitch (level) are taught concurrently. (PP)

  16. 77 FR 68149 - Karen Paul Holley, M.D.; Decision and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... authority, both the plain language of applicable federal statutory provisions and Agency interpretive... essential condition for obtaining and maintaining a DEA registration. Serenity Caf , 77 FR 35027, 35028 (2012); David W. Wang, 72 FR 54297, 54298 (2007); Sheran Arden Yeates, 71 FR 39130, 39131...

  17. Internet Links for Science Education: Student-Scientist Partnerships (edited by Karen Cohen)

    NASA Astrophysics Data System (ADS)

    Barden, Linda M.

    1998-10-01

    Plenum: New York, 1997. xx + 260 pp. Figs., tables, photos. 15 x 22.8 cm. ISBN 0-306-45558-7. $27.50. Science education is undergoing an upheaval more fundamental than the one that occurred in the aftermath of Sputnik. Research during the past 40 years has led to a radical change in the way we view children's learning of science. The National Science Education Standards (NSES) suggest a new model for teaching science based upon these research findings. Societal changes, particularly changes in business, have put pressure on schools to alter the emphasis of curricula from rote memory and individual competition to problem solving using a variety of technological skills and teamwork/team competition. This timely book addresses all these issues by describing projects that K-12 teachers can use to achieve the goals set forth by both NSES and business. It also provides scientists with examples of how they and their coworkers might better interact with K-12 science education to encourage a more scientifically literate society. Finally, it includes suggestions for future research in science education.

  18. Palaeointensity determinations on rocks from Palaeoproterozoic dykes from the Kaapvaal Craton (South Africa)

    NASA Astrophysics Data System (ADS)

    Shcherbakova, V. V.; Shcherbakov, V. P.; Zhidkov, G. V.; Lubnina, N. V.

    2014-06-01

    Palaeointensity study of the Proterozoic-Archean volcanic rocks from the Kaapvaal Craton South Africa) are reported. Palaeomagnetic study of this collection was performed earlier by Olsson et al. Electron microscope observations, thermomagnetic and hysteresis measurements indicate the presence of single-domain and pseudo-single-domain (SD-PSD) magnetite grains as the main magnetic mineral. The samples demonstrated a very good stability to heating, the electron micrograph observations revealed magnetite-ilmenite exsolution structure. Palaeointensity determinations were obtained by Coe-modified Thellier procedure. A total 58 samples from 14 sites were studied but only seven samples from one site NL28 of the Early Proterozoic age of 1.9 Ga passed palaeointensity selection criteria. Reliable palaeointensity determinations were obtained by both Thellier and Wilson methods on 18 cubes (subsamples) from site NL28 yielding rather low mean virtual dipole moment (VDM) = (2.82 ± 0.12) ×1022 Am2 which is in agreement with the suggestion of existence of the `Proterozoic dipole low period'.

  19. Flood of June 1972: Genesee River and Dyke Creek at Wellsville, New York

    USGS Publications Warehouse

    Wagner, L.A.; Hamecher, P.H.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  20. Flood of June 1972: Genesee River at Scio and Dyke Creek at Wellsville, New York

    USGS Publications Warehouse

    Wagner, L.A.; Hamecher, P.H.

    1972-01-01

    In June 1972, tropical storm Agnes caused sever flooding in Pennsylvania and southern New York. The flood, on many major streams were the highest known since the river valleys were settled. Maximum discharges were as much as twice the discharge of a 50-year flood. In southern New York, large areas in Corning, Elmire, Wellsville, Salamanca, and in many smaller communities were inundated to depths of several feet. Levels of all of the Finger Lakes were higher than any previously recorded, and extensive flooding of lakeside properties resulted. The extent of flooding shown on the map was delineated by the U.S. Geological Survey from earlier photography and limited field survey. The investigation was conducted in cooperation with the State of New York and the U.S. Army Corps of Engineers.

  1. Epidotisation and fluid flow in sheeted dyke complex : new field and experimental constraints

    NASA Astrophysics Data System (ADS)

    Coelho, Gabriel; Sizaret, Stanislas; Arbaret, Laurent; Branquet, Yannick; Champallier, Rémi

    2013-04-01

    Hydrothermal system in oceanic crust is usually studied via dredge samples and drilled holes but their equivalent are also found in ophiolitic complexes (Oman, Cyprus). In the deepest zone, the fluids react with the sheeted diabase dikes at 400°C and 400 bars to form epidosites by enrichment in epidote and quartz [1]. Mineralogy and chemistry of epidosites have been widely studied on fields [1] and hydrology is generally studied using numerical models [2]. However, the relations and the timing of the emplacement of diabase dikes, their alteration in epidosite and the regional deformation remain unclear. We performed experiments on diabase sampled in the Troodos complex (Cyprus), 1) to stress the P-T-fO2-fluid composition conditions of the reaction of epidotisation and, 2) to quantify interrelations between the permeability and the epidotisation during deformation. In Troodos, we observed two major types of epidosite: 1) a pervasive epidosite in the core of dikes and a banding which is parallel to chilled margins and, 2) assemblages of epidote and quartz as alteration fronts in cooling joints or in the form of veins cross-cutting non-epidotised dikes. This last type of epidotisation clearly appears to be a hydrothermal veining process. We synthesized epidote in a static autoclave with external heating at 500°C and 2500 bars. Epidote was formed by the following reaction: 6 albite + 2 hematite + anorthite + 7 Ca2+ + 6 H2O → 4 epidote + 8 quartz + 6 Na+ + 8 H+. The calculated variation of the molar volume is about -3% (creation of porosity). Two parameters are essential to synthesize epidote from diabase: the oxygen fugacity and the composition of the fluid (enriched in Ca and Fe). However, there is an obvious problem of nucleation at 400°C and 400 bars. In order to understand how fluid flows throughout sheeted dikes, in situ measurements of permeability during coaxial deformation have been performed in a Paterson apparatus by infiltration of Argon and water. The permeability of the diabase prior deformation is about 10-20 m2. After fracturation of the sample, the permeability increased rapidly up to 10-19 m2. After stress relaxation, the permeability decreased slowly to its initial permeability. Moreover, the permeability of epidosite is about 10-19 m2. So this suggests that epidotisation generates porosity. The main problem is the initiation of fluid flow because of the impermeability of diabase. From our results and field evidence, we suggest two hypotheses: 1) fluid flows via fractures and cracks and, 2) fluid flows into a rock in a subsolidus state (importance of degassing). To explore this last hypothesis, experiments will be performed at high temperature (T > 850°C) with an infiltration of water through a synthetic diabase placed under late magmatic conditions. So, in these conditions, nucleation of epidote could be facilitated from a glass. [1] Richardson C. J., Cann J. R., Richards H. G., Cowan J. G., 1987. Earth and Planetary Science Letters, 84, 243-253. [2] Coumou D., Driesner T., Geiger S., Heinrich C. A., Mattahai S., 2006. Earth and Planetary Science Letters, 245, 218-231.

  2. Sissies, Faggots, Lezzies, and Dykes: Gender, Sexual Orientation, and a New Politics of Education?

    ERIC Educational Resources Information Center

    Lugg, Catherine A.

    2003-01-01

    Seeks to chart a course through the contested area of gender and sexual orientation in hopes of establishing a theoretical framework and an agenda for much needed future research. Draws from two research traditions, particularly in the areas of history and law: neo-Marxist theory generally and Queer Legal Theory specifically. (Contains 161…

  3. A love letter from NADIA (non-anglo dykes in Australia).

    PubMed

    Kizinska, R

    1999-01-01

    This article is a revised version of a paper I presented at the "Sappho Was A Wog Grrrl" conference in Melbourne, 22 October 1995, which was organized by "Interlesbian," a Melbourne-based political and support group for lesbians from Non-English Speaking Backgrounds (NESB). Utilizing a mixed genre format incorporating the first person fictional narrative form of letters to lovers, this parodic piece explores the identity terrains of sexuality, ethnicity and class in Melbourne's lesbian communities. It focuses on how the ethnocentric limits of sexual, cultural and racial identifications constrain the mythical beauty of coming out and staying in. The experiences reported and reflected upon here arose out of my participation as an activist member of Interlesbian. Contextualized in the form of a lover's discourse, this paper is an evocation of a passion towards the (re)visioning of a progressive local lesbian activist politics and community. PMID:10197552

  4. The petrogenesis of late Neoproterozoic mafic dyke-like intrusion in south Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Azer, M. K.; Abu El-Ela, F. F.; Ren, M.

    2012-08-01

    New field, petrographical and geochemical studies are presented here for the late Neoproterozoic Rimm intrusion (˜15 km long) exposed in the southern Sinai Peninsula, Egypt in the northernmost Arabian-Nubian Shield (ANS). Field relations indicate that the Rimm intrusion is younger than the surrounding metamorphic rocks and calc-alkaline syn-tectonic granodiorite and it was not affected by regional metamorphism. The anorogenic peralkaline granite of Gebel Serbal crosscuts the Rimm intrusion. The Rimm intrusion is made up of several consanguineous rock types with gradational contacts. It is composed chiefly of pyroxene-hornblende gabbro, hornblende gabbro and minor quartz diorite. The chemical composition of the mafic minerals indicated that the studied rocks derived from calc-alkaline mafic magma. Geochemically, the studied rocks are characterized by enrichment in LILE relative to HFSE and LREE relative to HREE [(Ce/Yb)N = 4.50-6.36]. Quartz diorite display slightly concave HREE pattern and slightly negative Eu-anomaly [(Eu/Eu*)n = 0.91] which may be the result of fractionation of amphibole and plagioclase from the source melt, respectively. The Rimm intrusion evolved from mafic mantle magma into different type rocks by fractional crystallization with minor crustal contamination. The initial magma corresponds to pyroxene-hornblende gabbro and the crystallization of hornblende was caused by slight H2O increase in magma after crystallization of near-liquidus clinopyroxene and Ca-rich plagioclase. Amphiboles geobarometer indicate that the gabbroic rocks of the Rimm intrusion crystallized at pressures between 4.8 and 6.4 Kb, while quartz diorite crystallized at 1.3-2.1 Kb. Crystallization temperatures range between 800 and 926 °C for the gabbros and between 667 and 784 °C for the quartz diorite. The Rimm intrusion represents a post-orogenic phase formed during the crustal thinning and extension of the Arabian-Nubian Shield.

  5. Dyke Award. Evaluation of contrast-enhanced MR imaging in a brain-abscess model.

    PubMed

    Runge, V M; Clanton, J A; Price, A C; Herzer, W A; Allen, J H; Partain, C L; James, A E

    1985-01-01

    An alpha-streptococcus brain abscess was produced in five dogs and studied with magnetic resonance (MR) imaging (0.5 T) and computed tomography (CT). Non-contrast- and contrast-enhanced CT scans were obtained using gadolinium diethylenetriamine-pentaacetic acid (Gd DTPA) for MR imaging and meglumine iothalamate for CT scanning. Each animal was evaluated in the early and later cerebritis stages of abscess evolution. On MR, the area of cerebritis enhanced after administration of Gd DTPA in a manner similar to that observed with contrast-enhanced CT. However, contrast enhancement was greater on the MR examination. Early lesions in two animals were detected only with contrast-enhanced MR imaging. This experience suggests that intravenously administered agents such as Gd DTPA should increase the diagnostic potential of MR imaging in neurologic diseases, especially those altering the blood-brain barrier. PMID:3920873

  6. Recent progress in particle acceleration from the interaction between thin-foil targets and J-KAREN laser pulses

    SciTech Connect

    Nishiuchi, Mamiko; Pirozhkov, Alexander S.; Sakaki, Hironao; Ogura, Koichi; Esirkepov, Timur Zh; Tanimoto, Tsuyoshi; Yogo, Akifumi; Hori, Toshihiko; Sagisaka, Akito; Fukuda, Yuji; Kanasaki, Masato; Kiriyama, Hiromitsu; Shimomura, Takuya; Tanoue, Manabu; Nakai, Yoshiki; Sasao, Hajime; Sasao, Fumitaka; Kanazawa, Shuhei; Kondo, Shuji; Matsumoto, Yoshihiro; and others

    2012-07-11

    From the interaction between the high-contrast ({approx}more than 10{sup 10}) 130 TW Ti:sapphire laser pulse and Stainless Steel-2.5 um-thick tape target, proton beam with energies up to 23 MeV with the conversion efficiency of {approx}1% is obtained. After plasma mirror installation for contrast improvement, from the interaction between the 30 TW laser pulse and thin-foil target installed on the target holder with the hole whose shape is associated with the design of the well-known Wehnelt electrode of electron-gun, a 7 MeV intense proton beam is controlled dynamically and energy selected by the self-induced quasi-static electric field on the target holder. From the highly divergent beam having continuous spectrum, which are the typical features of the laser-driven proton beams from the interactions between the short-pulse laser and solid target, the spatial distribution of 7 MeV proton bunch is well manipulated to be focused to an small spots with an angular distribution of {approx}10 mrad. The number of protons included in the bunch is >10{sup 6}.

  7. Slab and sediment melting during subduction initiation: granitoid dykes from the mantle section of the Oman ophiolite

    NASA Astrophysics Data System (ADS)

    Rollinson, Hugh

    2015-09-01

    New geochemical data are presented for a suite of tonalites, granodiorites, trondhjemites and granites intrusive into depleted mantle harzburgites of the Oman-UAE ophiolite. A detailed field, petrological and geochemical examination suggests that these `mantle granitoids' are the product of three processes: (a) the mixing of melts derived from both mafic and metasedimentary sources, (b) interaction with the mantle harzburgite host and (c) the fractional crystallisation of plagioclase, hornblende ± accessory phases. Geochemical data are used to characterise the identity of the protolith(s) by first screening the data for those samples which have experienced fractional crystallisation during emplacement. The resultant `reduced' data set has moderately fractionated REE, with small negative Eu anomalies and fractionated primitive mantle-normalised trace element patterns with high concentrations of fluid mobile elements and lower concentrations of HFS elements and with positive peaks for Rb and Pb and negative troughs for Ba, Nb, Sr and Ti. The character of the protolith was quantified using a melting model based upon a MORB-type basalt similar in composition to the Oman Geotimes lavas and a model using the MUQ (MUd from Queensland) global sediment composition (Kamber et al. Geochim Cosmochim Acta 69:1041-1058, 2005) both with an amphibolite/granulite facies mineralogy. The two compositions bracket the mantle granitoid data set with partial melts of the MORB source yielding trace element compositions lower than the granitoids, whereas melts of the MUQ source yield melts with compositions higher than the granitoids. Mixing of the calculated melt compositions indicates that the measured granitoid compositions represent between 10 and 30 % mixing of a metasedimentary melt into the melt of a mafic source. Current petrological, structural and geochronological data suggest a model for the origin of the Oman ophiolite in which it is formed by spreading above a subduction zone. The results of this study support this model in three ways: (a) trace element data show that the granitoids have interacted with the mantle, implying that they originated below the mantle section of the ophiolite and were emplaced into the mantle wedge from below; (b) a most probable setting for the melting of a sediment-basalt mix is in the upper part of a subducting slab; (c) the high temperature/shallow melting of the sediment and basaltic slab mix can only have been driven by the high temperatures of the overlying mantle wedge; this is most likely during subduction initiation. Thus, sediment melting during subduction initiation represents an important means of refertilising what is otherwise highly depleted mantle.

  8. Social Networking and the School Adjustment of Karen Refugee Youth from Burma: Determining the Effects of Ethnic Identity, Bonding Social Capital, and Facebook Use

    ERIC Educational Resources Information Center

    Lewis, Lucy D.

    2013-01-01

    In 2011 alone, over 56,000 refugees were admitted to the United States and a third of these individuals were under the age of 18 (Martin & Yankay, 2012). Researchers have found that the social capital developed through close and confiding relationships is instrumental in the academic outcomes of refugee youth (Kia-Keating & Ellis, 2007;…

  9. Lessons Learned about Mothering a Child with a Sensory Modulation Disorder

    ERIC Educational Resources Information Center

    Wittman, Peggy P.; Velde, Beth P.; Lamm, Stacey; Mohler, Marie; Thomas, Linda King

    2007-01-01

    Three months after Karen's birth, her mother desperately tried to maintain her sanity. Karen's two brothers were fine, and Karen's twin slept, ate, and bonded with members of the family; Karen, on the other hand, was a screamer. "It was like someone was cutting her limbs off with a chain saw. It went on and on, and nothing we did comforted her;…

  10. Geochemistry of sapphirine-apatite-calcite-bearing gabbroic dykes from the Finero Phlogopite Peridotite (Ivrea-Verbano Zone): evidence for multistage interaction with the ambient peridotite

    NASA Astrophysics Data System (ADS)

    Tommaso, Giovanardi; Alberto, Zanetti; Maurizio, Mazzucchelli; Tomoaki, Morishita; Antonio, Langone

    2016-04-01

    The Finero Phlogopite-Peridotite (FPP) is a mantle unit outcropping in the northernmost tip of the Ivrea-Verbano Zone (IVZ, Southern Alps). It shows a virtually complete recrystallization due to pervasive to channelled melt migration. The pervasive metasomatism formed a main lithologic association constituted by phlogopite harzburgites associated to phlogopite pyroxenites (mainly olivine-websterites, websterites and orthopyroxenites). These lithologies are also rich in amphibole and do not show significant chemical gradients among them (Zanetti et al., 1999). The channelled migration stages formed dunite bodies, which sometimes contain stratiform chromitites and, more rarely, pyroxenite layers similar to those associated to phlogopite harzburgite. The FPP also shows a discrete number of other, subordinate rock-types, which are characterised by the presence of apatite usually associated to carbonates (i.e. calcite or dolomite) and exhibit marked modal and chemical gradients with respect to the host phlogopite harzburgite. Examples of these lithologies are apatite-dolomite-bearing wehrlites and harzburgites (e.g. Zanetti et al. 1999; Morishita et al., 2008), apatite-calcite zircon-syenites and hornblendites. Ar-Ar amphibole analysis and U-Pb zircon and apatite data return Triassic ages for these rocks, which have been considered to document the time of melt/fluid injection. Notwithstanding the apparent mineralogical and chemical differences with the main lithologic sequences, apatite-carbonates-bearing rocks have been frequently interpreted as cogenetic to phlogopite harzburgites. To debate the petrogenesis of these rocks, a detailed field, petrological and geochemical investigation has been carried out on a swarm of apatite-calcite-bearing gabbroic veins that randomly cut the main lithologic association. Preliminary investigation evidenced as these veins show complex metasomatic haloes and a symmetric internal layering, characterised by crystallisation of magmatic sapphirine (Giovanardi et al., 2013). The mineral assemblage of the veins is dominated by titanian pargasite towards the host peridotite and by plagioclase at the vein centre. The veins also present phlogopite and spinel. Field and petrographic evidence, major and trace element data and the O isotopic composition of such gabbroic veins indicate that they formed at shallow mantle conditions by multistage fractional crystallisation of a migrating melt unrelated to those forming phlogopite harzburgites. Besides, local strong enrichments in LILE, LREE and 18O in vein minerals confirm that such melt was deeply modified by interaction with the host phlogopite peridotite. The genetic relationships with other intrusive events recorded by the FPP and the associated crustal sequence will be addressed with the aim of placing new constraints on the petrologic and geodynamic evolution of the IVZ. Giovanardi, T., Morishita, T., Zanetti, A., Mazzucchelli, M., Vannucci, R. (2013). Igneous sapphirine as a product of melt-peridotite interactions in the Finero Phlogopite-Peridotite Massif, Western Italian Alps. European Journal of Mineralogy 25, 17-31. Morishita, T., Hattori, K.H., Terada, K., Matsumoto, T., Yamamoto, K., Takebe, M., Ishida, Y., Tamura, A., Arai, S. (2008). Geochemistry of apatite-rich layers in the Finero phlogopite-peridotite massif (Italian Western Alps) and ion microprobe dating of apatite. Chemical Geology 251, 99-111. Zanetti, A., Mazzucchelli, M., Rivalenti, G., Vannucci, R. (1999). The Finero phlogopite-peridotite massif: an example of subduction-related metasomatism. Contributions to Mineralogy and Petrology 134, 107-122.

  11. Sequential emplacement of sheeted plutons and sill-dyke complexes: implication on crustal anatexis and lifespan of hydrothermal/geothermal systems

    NASA Astrophysics Data System (ADS)

    Dini, A.

    2014-12-01

    Depending on initial melt composition, magma volumes, transfer rates, depth of emplacement and tectonic conditions, granite magmas can follow different crystallization paths leading to complex patterns of magmatic fluid/heat release and water-rock interaction in the host rocks at the emplacement level. In the case of multi-pulse magmatic complexes, several contact metamorphic and hydrothermal effects can overlap through time on a relatively small crustal portion. The net result of the described complex evolution is a magmatic system, where magmatic fluid exsolution, heat flow and triggering of meteoric fluid convection cells follow cyclically transient patterns with strong implication on ore forming processes and geothermal field lifespan. Detailed field mapping, coupled with petrographic-geochronologic-geochemical-isotopic data on Late Miocene-Pleistocene granite intrusions in Tuscany provided new insights on melting processes occurred in the roots as well as on paleo-hydrothermal circuits triggered at the roof of the intrusive complexes. Tuscan granite intrusions were constructed incrementally by amalgamation (sheeted plutons) and/or multilayer dispersion (sills and laccoliths) of different magma pulses, sequentially produced as the Apennine fold belt was progressively thinned, heated and intruded by mafic magmas. Partial melting was probably triggered by multiple, small-sized mafic intrusions, that allowed temporary overstepping of dehydration melting reactions into the already pre-heated crust. Dilution in time of the magmatic activity prevented melt homogenization at depth, allowing the formation at the emplacement level of multiple, isotopically distinct, intrusive sheets instead of a single, homogeneous, hybrid pluton. This could be also one of the major key factors explaining the prolonged hydrothermal activity recorded in this area by both fossil (Plio-Pleistocene ore deposits) and active (Larderello geothermal field) systems.

  12. Unruptured Brain Aneurysms

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  13. Brain Aneurysm: Treatment Options

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  14. Brain Aneurysm: Recovery

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  15. Subarachnoid Hemorrhage

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  16. Brain Aneurysm Warning Signs/Symptoms

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  17. Brain Aneurysm Statistics and Facts

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  18. Family History

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  19. Aneurysm Complications

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  20. Brain Aneurysm: Dealing with Emotional Distress

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  1. Brain Aneurysm: Early Detection and Screening

    MedlinePlus

    ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ... The Christopher C. Getch, MD Chair of Research Carol W. Harvey Memorial Chair of Research The Karen ...

  2. A large scale investigation into changes in coal quality caused by dolerite dykes in Secunda, South Africa-implications for the use of proximate analysis on a working mine

    NASA Astrophysics Data System (ADS)

    Bussio, John P.; Roberts, James R.

    2016-05-01

    The coalfields of South Africa contain numerous dolerite intrusions, which affected the quality of the surrounding coal through thermal processes, commonly believed to be controlled by the size of the magmatic body. Data gathered from a working coalfield in Secunda, South Africa, suggest that the relationship between intrusive sills and coal is complex and factors other than intrusion width must be considered in relation to the contact metamorphic effect. The study area contains multiple dolerite intrusions of Karoo age, of which three intrusions occur as sills intruded close to the main coal seam of the. A large database (>8000 boreholes) of coal quality data was used to investigate the presence or absence of a change in coal quality relative to dolerite proximity. Reduction in coal quality was defined using three proximate analysis values, namely the ash, volatile content and dry ash free volatile (DAFV) as defined in the coal industry. The resultant investigation showed no correlation between the position and thickness of the dolerites, and changes in coal quality as measured by proximate analysis. In the absence of a linear relationship between coal quality and dolerite proximity, two processes are proposed to explain the absence of the contact metamorphic effects expected from previous studies. Firstly dolerite emplacement dynamics may influence the size of the metamorphic aureole produced by an intrusion, invalidating intrusion size as a measure of thermal output. Secondly, hydrothermal fluids mobilised by the dolerite intrusions, either from the country rock or the intrusion itself may percolate through the coal and act as the metamorphic agent responsible for changing coal quality, by dissolving the volatile and semi-volatile components of the coal and transporting them to other locations. These two processes are sufficient to explain the lack of a clear "metamorphic effect" related to the dolerite intrusions. However, the perceived lack of a clear correlation between the coal quality parameters and the metamorphic effects associated with dolerite intrusion may also reflect the inadequacies of proximate analysis techniques in quantifying geological processes within the coal.

  3. Retraction notice to "Ca. 2.5 billion year old mafic dykes in western Shandong Province: Implications for hybridization between subducted continental crust and the North China Craton, China"

    NASA Astrophysics Data System (ADS)

    Liu, Shen; Feng, Caixia; Zhai, Mingguo; Hu, Ruizhong; Gao, Shan; Lai, Shaocong; Zou, Haibo; Yan, Jun

    2015-02-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editors-in-Chief. The article duplicates significant parts of a paper that had already appeared in, and was withdrawn from Precambrain Research (http://dx.doi.org/10.1016/j.precamres.2014.08.012") One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper is not under consideration for publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  4. Expedition 36 Crew Profile

    NASA Video Gallery

    Learn more about Expedition 36 Commander Pavel Vinogradov and Flight Engineers Chris Cassidy, Alexander Misurkin, Karen Nyberg, Fyodor Yurchikhin and Luca Parmitano and their mission aboard the Int...

  5. 76 FR 56196 - Notice of Agreement Filed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... Counsel & Environmental Officer, CMA CGM (America) LLC, 5701 Lake Wright Drive, Norfolk, VA 23502... the Federal Maritime Commission. Dated: September 7, 2011. Karen V. Gregory, Secretary. BILLING...

  6. New Crewmates Welcomed Aboard Station

    NASA Video Gallery

    NASA astronaut Karen Nyberg, Russian Federal Space Agency cosmonaut Fyodor Yurchikhin and European Space Agency astronaut Luca Parmitano joined their Expedition 36 crewmates when the hatches betwee...

  7. Photograph of the month

    NASA Astrophysics Data System (ADS)

    2016-08-01

    Dykes in the Bidkhan strato-volcano located in the south eastern part of the Urumieh - Dokhtar magmatic arc, south west of Kerman, Iran. Repetitive dykes intrude through Oligo-Miocene Bidkhan pyroclastic sediments. A light dacitic dyke grew syntaxially within a gray andesitic dyke. The dykes trend NE and cross Oligo- Miocene lahar and pyroclastic sediments of the south west part of Bidkhan volcano caldera. Width of view appr. 10m. South of Bardsir city, SW Kerman, Iran. 29° 33.267≠ N, 056°, 27.25≠ E. Photograph © Reihaneh Keihanizadeh, Kerman, Iran. (http://keihanizadeh@gmail.com)

  8. "Positive Discipline": Beginnings Workshop.

    ERIC Educational Resources Information Center

    Stephens, Karen; And Others

    1992-01-01

    Four articles in this special section discuss (1) ideas for making discipline a positive experience for child care staff and children (Karen Stephens); (2) scenarios illustrating the power of adult messages to children (Karen Stephens); (3) classroom environments that facilitate positive discipline (Marjorie K. Kostelnik); and (4) strategies for…

  9. Curricular Pillars in the Elementary General Music Classroom

    ERIC Educational Resources Information Center

    Howell, Allen C.

    2009-01-01

    Karen, a veteran elementary general music teacher, was bewildered when she learned that none of her students remembered "Peter and the Wolf," a music lesson they have encountered in the past. Conscientious beginning elementary general music teachers like Karen may work diligently to plan instruction that will ensure that national, state, and local…

  10. 76 FR 70711 - Senior Executive Service; Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-15

    ..., KAREN C HALE, ANDREW M HALLMAN, TIMOTHY J HANDWERKER, ALAN I HANNIGAN, JAMES J HARDWICK JR, RAYMOND J... HARTMAN, JOHN R HARVEY, STEPHEN J HASS, RICKEY R HELD, EDWARD B HENDERSON III, CLYDE H HENNEBERGER, KAREN..., BARBARA N MCKENZIE, JOHN M MCRAE, JAMES BENNETT MEACHAM, A AVON MEEKS, TIMOTHY J MELLINGTON, STEPHEN...

  11. Transforming Content Knowledge: Learning to Teach about Isotopes.

    ERIC Educational Resources Information Center

    Geddis, Arthur N.; And Others

    1993-01-01

    Presents a vignette about Karen, a student teacher in her first attempt at teaching chemical isotopes. Karen focuses on transmitting what she knows. An overview of Schulman's conceptions of pedagogical content knowledge is then provided. Shulman's ideas are employed to frame the experiences of Alan, a student teacher, as he and his cooperating…

  12. 76 FR 18765 - National Advisory Council for Healthcare Research and Quality: Request for Nominations for Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... of health care economics, information systems, law, ethics, business, or public policy; and, (7) in.... Nominations may also be e-mailed to Karen.Brooks@ahrq.hhs.gov . FOR FURTHER INFORMATION CONTACT: Ms. Karen Brooks, AHRQ, at (301) 427- 1801. SUPPLEMENTARY INFORMATION: 42 U.S.C. 299c provides that the...

  13. Setting the Standard: Role Definition for a Secondary Literacy Coach

    ERIC Educational Resources Information Center

    DiMeglio, Rachele A.; Mangin, Melinda M.

    2010-01-01

    This case introduces Karen, a middle school literacy coach attempting to navigate the myriad tasks she performs. As she aims to satisfy everyone's needs Karen struggles to prioritize and focus her work. The accompanying teaching notes utilize the International Reading Association's "Standards for Middle and High School Literacy Coaches" to…

  14. HIV/AIDS and Infections - Multiple Languages: MedlinePlus

    MedlinePlus

    ... sharing features on this page, please enable JavaScript. French (français) Karen (Sgaw Karen) Nepali (नेपाली) Somali (af Soomaali) Spanish (español) Swahili (Kiswahili) French (français) Opportunistic Infections English Infections opportunistes - français (French) ...

  15. Living with HIV/AIDS - Multiple Languages: MedlinePlus

    MedlinePlus

    ... sharing features on this page, please enable JavaScript. French (français) Karen (Sgaw Karen) Nepali (नेपाली) Somali (af Soomaali) Spanish (español) Swahili (Kiswahili) French (français) Sharing Your HIV Status English Communiquer son ...

  16. Coming Out of the Classroom Closet: Gay and Lesbian Students, Teachers and Curricula.

    ERIC Educational Resources Information Center

    Harbeck, Karen M., Ed.

    This book presents a collection of 10 research reports and essays on homosexuality and education. After an introduction by Karen M. Harbeck, chapters include: (1) "Addressing the Needs of Lesbian, Gay, and Bisexual Youth: The Origins of PROJECT 10 and School-Based Intervention" (Virginia Uribe and Karen M. Harbeck); (2) "Educators, Homosexuality,…

  17. Beyond Terman: Contemporary Longitudinal Studies of Giftedness and Talent.

    ERIC Educational Resources Information Center

    Subotnik, Rena F., Ed.; Arnold, Karen D., Ed.

    This volume presents 16 papers describing recent longitudinal studies of giftedness. Papers have the following titles and authors: (1) "Longitudinal Study of Giftedness and Talent" (Rena F. Subotnik and Karen D. Arnold); (2) "The Illinois Valedictorian Project: Early Adult Careers of Academically Talented Male High School Students" (Karen D.…

  18. Solidification of basaltic magma during flow in a dike.

    USGS Publications Warehouse

    Delaney, P.T.; Pollard, D.D.

    1982-01-01

    A model for time-dependent unsteady heat transfer from magma flowing in a dyke is developed. The ratio of solidification T to magma T is the most important parameter. Observations of volcanic fissure eruptions and study of dykes near Ship Rock, New Mexico, show that the low T at dyke margins and the rapidly advancing solidification front predicted by the model are qualitatively correct.-M.S.

  19. Comment on ‘Magnetic studies of magma-supply and sea-floor metamorphism: Troodos ophiolite dikes’, by G.J. Borradaile and D. Gauthier

    NASA Astrophysics Data System (ADS)

    Callot, Jean-Paul; Geoffroy, Laurent; Aubourg, Charles

    2007-04-01

    Anisotropy of magnetic susceptibility is used as a proxy for the determination of magmatic flow direction in mafic dykes. Here we take advantage of the dataset from G.J. Borradaile and D. Gauthier to comment three points: (1) the sampling strategy; (2) the geometric relationship between magnetic axis dyke, and, (3) an alternative interpretation to obtain a flow direction. The magnetic lineations published by Borradaile and Gauthier correspond to the zone axis of the dyke and magnetic foliation poles, questioning the reliability of the magnetic lineation as a flow estimate. An alternative interpretation is based on the use of the tiling of the magnetic foliation plane against the dyke wall.

  20. Doubts About the National Agenda of "Self-Managing" Chronic Conditions.

    PubMed

    Zander, Karen

    2015-01-01

    What comes to mind when I hear the name Karen Zander: case manager pioneer, brilliant and compassionate nurse leader, articulate teacher, mentor, and friend. Karen has a unique perspective on health care today as a consumer and provider. While she manages through physical limitations, it has never diminished her passion, commitment or can-do spirit. Her contributions to the case management practice are broad based and invaluable. It is with pleasure and gratitude that we welcome Karen as a guest columnist. PMID:26241625

  1. Soyuz Completes Expedited Flight to Station

    NASA Video Gallery

    The Soyuz TMA-09M spacecraft carrying Soyuz Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano docks with the International Space Station less than six hours after its...

  2. Tuskegee Airmen Episode 2

    NASA Video Gallery

    Karen Ricks, DLN Coordinator at NASA Langley Research Center, conducts an interview with Tuskegee Airmen Sgt. Harry Quinton, about his experiences with the Tuskegee Airmen along with the history of...

  3. 78 FR 52505 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... National Institute of Standards and Technology (NIST) announces that the Manufacturing Extension... FURTHER INFORMATION CONTACT: Karen Lellock, Manufacturing Extension Partnership, National Institute...

  4. 75 FR 50749 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... announces that the Manufacturing Extension Partnership (MEP) Advisory Board, National Institute of Standards... INFORMATION CONTACT: Karen Lellock, Manufacturing Extension Partnership, National Institute of Standards...

  5. 78 FR 78821 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... National Institute of Standards and Technology (NIST) announces that the Manufacturing Extension... SUPPLEMENTARY INFORMATION section of this notice. FOR FURTHER INFORMATION CONTACT: Karen Lellock,...

  6. Senior Centers

    MedlinePlus Videos and Cool Tools

    ... something many older adults would like to do as long as they can. Senior centers, adult day care, transportation, ... adults who live independently can go to find a variety of social and recreational activities. [Karen Albers] ...

  7. 75 FR 70289 - Notice of Appointment of Individuals to Serve as Members of Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    .... Williamson Vice-Chair of the PRB: Commissioner Daniel R. Pearson Member: David Beck Member: Catherine DeFilippo Member: Robert B. Koopman Member: Karen Laney Member: Lynn I. Levine Member: James M. Lyons...

  8. 75 FR 38549 - Notice of Appointment of Individuals To Serve as Members of Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    .... Pearson. Vice-Chair of the PRB: Commissioner Dean A. Pinkert. Member--David Beck. Member--Catherine DeFilippo. Member--Robert B. Koopman. Member--Karen Laney. Member--Lynn I. Levine. Member--James M....

  9. 78 FR 49515 - Notice of Agreements Filed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ... Counsel; CMA CGM (America), LLC. 5701 Lake Wright Drive, Norfolk, VA 23502-1868. Synopsis: The amendment..., 2013. By Order of the Federal Maritime Commission. Karen V. Gregory, Secretary. BILLING CODE P...

  10. A potpourri of practical (or not) projectiles

    NASA Astrophysics Data System (ADS)

    Riendeau, Diane

    2010-11-01

    Special thanks to Frank Noschese, John Jay High School, and Karen Boone, Hallettsville High School. If you have a favorite video, please send the link and a brief description to: Diane Riendeau at driendeau@dist113.org.

  11. Expedition 36/37 Crew Preps for Launch

    NASA Video Gallery

    Soyuz Commander Fyodor Yurchikhin of the Russian Federal Space Agency, NASA astronaut Karen Nyberg and European Space Agency astronaut Luca Parmitano prepare for their May 28 Soyuz launch to join t...

  12. 77 FR 32977 - Announcement of Funding Awards for Fiscal Year 2012 Transformation Initiative: Choice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ... Investigator: Matthew Gebhardt. Grant: $76,948. 3. University of California--Berkeley (UC). Address: 2150 Shattuck Avenue, Suite 300, Berkeley, CA 94794-5940. Co-Principal Investigators: Karen Chapple,...

  13. 77 FR 20790 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-06

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... announces that the Manufacturing Extension Partnership (MEP) Advisory Board, National Institute of Standards... INFORMATION section below. FOR FURTHER INFORMATION CONTACT: Karen Lellock, Manufacturing Extension...

  14. 76 FR 53666 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-29

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... National Institute of Standards and Technology (NIST) announces that the Manufacturing Extension...: Karen Lellock, Manufacturing Extension Partnership, National Institute of Standards and Technology,...

  15. 78 FR 32240 - Manufacturing Extension Partnership Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... National Institute of Standards and Technology Manufacturing Extension Partnership Advisory Board AGENCY... National Institute of Standards and Technology (NIST) announces that the Manufacturing Extension... SUPPLEMENTARY INFORMATION section of this notice. FOR FURTHER INFORMATION CONTACT: Karen Lellock,...

  16. Expedition 36 Crew Launches on Fast Track to Station

    NASA Video Gallery

    The Soyuz TMA-09M spacecraft carrying Soyuz Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano launches from the Baikonur Cosmodrome in Kazakhstan to begin an expedite...

  17. Expedition 36 Final Exams and Training

    NASA Video Gallery

    The Expedition 36 crew members conduct final training at the Gagarin Cosmonaut Training Center before their May 28 launch to the International Space Station. Flight Engineers Karen Nyberg, Fyodor Y...

  18. Friends of the National Library of Medicine 2012 Annual Awards Gala | NIH MedlinePlus the Magazine

    MedlinePlus

    ... MD, MHS, Professor, Johns Hopkins Bloomberg School of Public Health Distinguished Health Communications Award: Karen Hunter, Senior Vice President Global Academic & Customer Relations, Elsevier Michael DeBakey Library Services Outreach Award: Anna ...

  19. 76 FR 63618 - Notice of Agreements Filed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... Singapore. Agreement No.: 012138. Title: CSAV/CCNI Venezuela Space Charter Agreement. Parties: Compana Sud... Venezuela. Dated: October 7, 2011. By Order of the Federal Maritime Commission. Karen V. Gregory,...

  20. Gestational Diabetes May Lead to More Body Fat on Babies

    MedlinePlus

    ... study lead author Karen Logan of Imperial College London. "This new study suggests diabetes in the mother ... author Neena Modi, a professor at Imperial College London, "Previous studies have suggested that diabetes may cause ...

  1. Asking gender questions

    NASA Astrophysics Data System (ADS)

    Pritchard, Jonathan; Masters, Karen; Allen, James; Contenta, Filippo; Huckvale, Leo; Wilkins, Stephen; Zocchi, Alice

    2014-12-01

    Jonathan Pritchard, Karen Masters, James Allen, Filippo Contenta, Leo Huckvale, Stephen Wilkins and Alice Zocchi report on a survey of the gender of astronomers attending and asking questions at this year's UK National Astronomy Meeting.

  2. Tuskegee Airmen Episode 3

    NASA Video Gallery

    Karen Ricks, DLN Coordinator at NASA Langley Research Center, conducts an interview with Tuskegee Airmen Cpl. Wilbert Gore Senior, about his experiences with the Tuskegee Airmen along with the hist...

  3. 75 FR 16111 - Antimicrobial Pesticide Products; Registration Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-31

    ...: Hydrogen peroxide; Peroxyacetic acid. Proposed Uses: Treatment of wastewater and sewage. Contact: Karen..., TX 77098. Active ingredient: Hydrogen peroxide. Proposed Uses: Sterilant for aseptic food packaging... USA, LLC, 122 C Street, NW, Suite 740, Washington DC 20001. Active ingredient: Hydrogen...

  4. Group Grammar

    ERIC Educational Resources Information Center

    Adams, Karen

    2015-01-01

    In this article Karen Adams demonstrates how to incorporate group grammar techniques into a classroom activity. In the activity, students practice using the target grammar to do something they naturally enjoy: learning about each other.

  5. FINDING THE SOMETHING IN NOTHING.

    PubMed

    Robbins, Michael

    2016-07-01

    Formless Infinity: Clinical Explorations of Matte Blanco and Bion. By Riccardo Lombardi. Translated by Karen Christenfeld, Gina Atkinson, Andrea Sabbadini, and Philip Slotkin. London/New York: Routledge, 2016. 282 pp. PMID:27428588

  6. Tuskegee Airmen Episode 1

    NASA Video Gallery

    Karen Ricks, DLN Coordinator at NASA Langley Research Center, conducts an interview with Tuskegee Airmen Chief Master Sgt. Grant Williams Senior, about his experiences with the Tuskegee Airmen alon...

  7. Tuskegee Airmen Episode 4

    NASA Video Gallery

    Karen Ricks, DLN Coordinator at NASA Langley Research Center, conducts an interview with Tuskegee Airmen Lieut. Col. Terrence Spann, about his experiences with the Tuskegee Airmen along with the hi...

  8. Expedition 36/37 Crew Launch Preps in Kazakhstan

    NASA Video Gallery

    Soyuz Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano arrive in Kazakhstan to prepare for their upcoming launch to the International Space Station. They are targete...

  9. Geochemistry and Ar-Ar muscovite ages of the Daraban Leucogranite, Mawat Ophiolite, northeastern Iraq: Implications for Arabia-Eurasia continental collision

    NASA Astrophysics Data System (ADS)

    Mohammad, Yousif O.; Cornell, David H.; Qaradaghi, Jabbar H.; Mohammad, Fahmy O.

    2014-06-01

    Daraban Leucogranite dykes intruded discordantly into the basal serpentinized harzburgite of the Mawat Ophiolite, Kurdistan region, NE Iraq. These coarse grained muscovite-tourmaline leucogranites are the first leucogranite dykes identified within the Mawat Ophiolite. They are mainly composed of quartz, K-feldspar, plagioclase, tourmaline, muscovite, and secondary phologopite, while zircon, xenotime, corundum, mangano-ilemnite and cassiterite occur as accessories.

  10. Two Cenozoic tectonic events of N-S and E-W extension in the Lhasa Terrane: Evidence from geology and geochronology

    NASA Astrophysics Data System (ADS)

    Huang, Feng; Xu, Ji-Feng; Chen, Jian-Lin; Wu, Jian-Bin; Zeng, Yun-Chuan; Xiong, Qiu-Wei; Chen, Xue-Feng; Yu, Hong-Xia

    2016-02-01

    Cenozoic active structures in the Tibetan Plateau are mainly regional N-S trending extensional faults and grabens, and E-W trending extensional tracks that are related to the transition from syn- to post-collision between India and Asia. E-W trending tracks are parallel to the direction of Neo-Tethyan oceanic convergence and consist of extensional volcanic-sedimentary basins and magmatic dykes in the southern Lhasa Terrane, Tibet. N-S trending tracks comprise faults and grabens, which are widely developed in Tibet. It remains unknown how and when the geodynamic transition from E-W to N-S trending tectonic tracks occurred. This study describes both E-W and N-S trending tectonic tracks identified at Dazi area of southern Lhasa Terrane, where E-W trending mafic dykes intruded a granitoid and late-stage N-S trending felsic dykes cut across E-W trending mafic dykes. Zircons from four granitoid samples yield consistent crystallization ages of ca. 60 Ma and positive εHf(t) values (~+ 9). An altered dioritic vein, which cuts the mafic dykes, yields an age of ca. 53 Ma. These new dating results indicate that E-W trending dykes, which formed due to regional N-S extension, were emplaced between 60 and 53 Ma. In addition, two N-S trending monzonitic porphyritic dykes, which cut the mafic dykes, yield U-Pb zircon ages of ca. 17 Ma with moderate positive εHf(t) values (+ 3 to + 9.6), as well as a NNE-SSW trending quartz monzonitic dyke, which cuts all other types of dykes, yields U-Pb ages of ca. 13 Ma. This suggests that E-W extension took place between 17 and 13 Ma. These results, in combination with existing age data for Gangdese granitoids and mafic magmatism, indicate the occurrence of two major extensional events at 60-53 Ma and 17-13 Ma. In turn, this implies that the transition from E-W to N-S trending tectonic and the onset of E-W extension occurred at ca. 17 Ma or slightly earlier. Paleocene granitoids have geochemical characteristics that are indicative of both

  11. Magma flow pictured by magnetic fabric on the Okavongo giant dikes swarm (Botswana)

    NASA Astrophysics Data System (ADS)

    Tshoso, G.; Aubourg, C.; Le Gall, B.; Tiercelin, J. J.; Kampuzu, H.

    2003-04-01

    The Okavango dyke swarm is 2000 km long and 100 km large. It is one of the feeders of the Karoo (178 Ma) basaltic igneous province in southern Africa. It is the NW branch of three dykes swarm intersecting in Mozambique. This system is generally related to the Nuanetsi plume, precluding the fragmentation of Eastern Gondwana. In this hypothesis, radial flow from this plume can be expected in the dyke swarm. We aim to elucidate the magma flow direction along two sections (Shashe and Thune) within the Okavango dyke swarm. While Karoo dykes are outcropping within the cratonic basement in the Shashe section, Karoo dykes from Thune river pierced Karoo sediments. We adopted sampling scheme in order to document imbrication of magnetic foliation and magnetic lineations. Consequently, we sampled both margins of (0.5 m to (50m, fresh to weathered, basaltic dykes. The overall quality of magnetic fabric data is rather poor and only 30% of dikes provide reliable magma flow direction. We observe that quality diminishes from center of the dyke to the margins, suggesting effect of alteration along margins. We present key examples where additional tests (anisotropy of anhysteretic magnetization, optical determination of plagioclases, demagnetization of natural remanent magnetization) provide interesting constraints to the understanding of magnetic fabric. In particular, we show that demagnetizing NRM permits to identify imbrication geometric on one dyke. By contrast, all tests performed on one dike characterized by abnormal horizontal magnetic foliation indicate that this foliation is not an artifact. When interpreting magnetic fabric as a whole, we observe that horizontal flow is dominant, ruling out vertical feeding. If NW sense of flow seems to be better expressed, SE flow is also recognized thus arguing against a general flow to the NW.

  12. INTERIOR FOURTH FLOOR, SOUTH HALF, LOOKING SOUTH. NOTE MUSHROOM COLUMNS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR FOURTH FLOOR, SOUTH HALF, LOOKING SOUTH. NOTE MUSHROOM COLUMNS AND CEILING HAS WOODEN NAILERS. - Colt Fire Arms Company, North Armory, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  13. INTERIOR SECOND FLOOR EAST END LOOKING WEST AT NORTH ROW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR SECOND FLOOR- EAST END LOOKING WEST AT NORTH ROW OF MUSHROOM COLUMNS. - Colt Fire Arms Company, South Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  14. How the differential load induced by normal fault scarps controls the distribution of monogenic volcanism

    NASA Astrophysics Data System (ADS)

    Maccaferri, Francesco; Acocella, Valerio; Rivalta, Eleonora

    2016-04-01

    Understanding shallow magma transfer and the related vent distribution is crucial for volcanic hazard. In the present study we investigate the link between the stress induced by topographic scarps and the distribution of monogenic volcanoes at divergent plate boundaries. With a numerical model of dyke propagation we show that vertical dykes beneath a normal fault scarp tend to deflect towards the footwall side of the scarp. This effect increases with the scarp height, is stronger for dykes propagating underneath the hanging wall side, and decreases with the distance from the scarp. A comparison to the East African Rift System, Afar and Iceland shows that: 1) the inner rift structure, which shapes the topography, controls shallow dyke propagation; 2) differential loading due to mass redistribution affects magma propagation over a broad scale range (100 - 105 m). Our results find application to any volcanic field with tectonics- or erosion-induced topographic variations.

  15. INTERIOR FIFTH FLOOR, LOOKING WEST SHOWING MONITOR. ROOM MOST RECENTLY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR FIFTH FLOOR, LOOKING WEST SHOWING MONITOR. ROOM MOST RECENTLY USED FOR ART STUDIO. - Colt Fire Arms Company, North Armory, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  16. ELEVATION OF CENTRAL BAY TO NORTH WING OF EAST ARMORY. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ELEVATION OF CENTRAL BAY TO NORTH WING OF EAST ARMORY. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  17. INTERIOR STRUCTURAL DETAIL, INSIDE OF DRUM UNDER DOME ON STAIRS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR STRUCTURAL DETAIL, INSIDE OF DRUM UNDER DOME ON STAIRS, LOOKING SOUTH. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  18. FOURTH FLOOR, NORTH HALF. VIEW NORTH SHOWING LINE OF PHOENIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FOURTH FLOOR, NORTH HALF. VIEW NORTH SHOWING LINE OF PHOENIX COLUMNS. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  19. PERSPECTIVE VIEW OF CENTRAL BAY OF EAST ARMORY, LOOKING SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PERSPECTIVE VIEW OF CENTRAL BAY OF EAST ARMORY, LOOKING SOUTH SOUTHEAST. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  20. ELEVATION LOOKING SOUTH OF EAST ARMORY ON LEFT, NORTH ARMORY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ELEVATION LOOKING SOUTH OF EAST ARMORY ON LEFT, NORTH ARMORY ON RIGHT. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  1. DOME, NORTH ARMORY ON LEFT, OBLIQUE VIEW FROM SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DOME, NORTH ARMORY ON LEFT, OBLIQUE VIEW FROM SOUTHWEST. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  2. FOUNDRY SHOP, FORGE SHOP, NORTH ARMORY, EAST ARMORY. Colt ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FOUNDRY SHOP, FORGE SHOP, NORTH ARMORY, EAST ARMORY. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  3. STAIRWAY OFF ENTRANCE LOBBY, PANELING TO LEFT ADDED IN 1995. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    STAIRWAY OFF ENTRANCE LOBBY, PANELING TO LEFT ADDED IN 1995. - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  4. OVERALL VIEW OF BASEMENT LEVEL LOOKING SOUTHEAST ( SAME LEVEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERALL VIEW OF BASEMENT LEVEL LOOKING SOUTHEAST ( SAME LEVEL AS CYLINDER HEADS IN PREVIOUS VIEWS). - Colt Fire Arms Company, East Armory Building, 36-150 Huyshope Avenue, 17-170 Van Dyke Avenue, 49 Vredendale Avenue, Hartford, Hartford County, CT

  5. How the differential load induced by normal fault scarps controls the distribution of monogenic volcanism

    NASA Astrophysics Data System (ADS)

    Maccaferri, F.; Acocella, V.; Rivalta, E.

    2015-09-01

    Understanding shallow magma transfer and the related vent distribution is crucial for volcanic hazard. Here we investigate how the stress induced by topographic scarps linked to normal faults affects the distribution of monogenic volcanoes at divergent plate boundaries. Our numerical models of dyke propagation below a fault scarp show that the dykes tend to propagate toward and erupt on the footwall side. This effect, increasing with the scarp height, is stronger for dykes propagating underneath the hanging wall side and decreases with the distance from the scarp. A comparison to the East African Rift System, Afar and Iceland shows that (1) the inner rift structure, which shapes the topography, controls shallow dyke propagation; (2) differential loading due to mass redistribution affects magma propagation over a broad scale range (100-105 m). Our results find application to any volcanic field with tectonics- or erosion-induced topographic variations and should be considered in any volcanic hazard assessment.

  6. 78 FR 39828 - Proposed Collection; Comment Request for Forms 8857 and 8857(SP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Service, Room 6129, 1111 Constitution Avenue NW., Washington, DC 20224. FOR FURTHER INFORMATION CONTACT... Dyke at Internal Revenue Service, room 6129, 1111 Constitution Avenue NW., Washington, DC 20224, or...

  7. #WomenInSTEM: Identifying an Opportunity for Change

    ScienceCinema

    Lefkowitz, Karen

    2014-11-24

    Karen Lefkowitz remembers being the only woman in the room thirty years ago at a conference when she started her career off as a computer programmer. Karen is a firm supporter of mentors and states that women, no matter whether they're in science or any other career, should ask for someone to mentor them. Karen is currently Vice President of Business Transformation at Pepco Holdings, Inc. She is responsible for the deployment of Advanced Metering Infrastructure (AMI) meters, a Department of Energy funded project, in Delaware, DC and Maryland. The meters have a two-way wireless communication that provides hourly consumption data at the premise allowing customers to take control of their energy use.

  8. #WomenInSTEM: Identifying an Opportunity for Change

    SciTech Connect

    Lefkowitz, Karen

    2014-10-20

    Karen Lefkowitz remembers being the only woman in the room thirty years ago at a conference when she started her career off as a computer programmer. Karen is a firm supporter of mentors and states that women, no matter whether they're in science or any other career, should ask for someone to mentor them. Karen is currently Vice President of Business Transformation at Pepco Holdings, Inc. She is responsible for the deployment of Advanced Metering Infrastructure (AMI) meters, a Department of Energy funded project, in Delaware, DC and Maryland. The meters have a two-way wireless communication that provides hourly consumption data at the premise allowing customers to take control of their energy use.

  9. 2D dynamical magma propagation modeling: application to the 2001 Mount Etna eruption

    NASA Astrophysics Data System (ADS)

    Pinel, Virginie; Carrara, Alexandre; Maccaferri, Francesco; Rivalta, Eleonora; Corbi, Fabio

    2016-04-01

    Numerical and analog studies of dike propagation in a stress field induced by volcanic edifice construction have shown that surface loading tends both to attract the magma and to reduce its velocity. Available numerical models can either calculate the trajectory or the velocity of the ascending dikes, but not both of them simultaneously. We developed a hybrid model of dyke propagation in two dimensions solving both for the magma trajectory and velocity as a function of the source overpressure, the magma physical properties (density and viscosity) as well as the crustal density and stress field. We first calculate a dyke trajectory in 2D and secondly run a 1D dynamical model of dyke propagation along this trajectory taken into account the influence of the stress field seen by the magma along this path. This model is used to characterize the influence of surface load on magma migration towards the surface and compared to previous results obtained by analog modeling.We find that the amplitude of dyke deflection and magma velocity variation depend on the ratio between the dyke driving pressure (source overpressure as well buoyancy) and the stress field perturbation. Our model is then applied to the July 2001 eruption of Etna, where the final dyke deflection had been previously interpreted as due to the topographic load by Bonaccorso et al. [2010]. We show that the velocity decrease observed during the last stage of the propagation can also be attributed to the local stress field. We use the dyke propagation duration to estimate the magma overpressure at the dyke bottom to be less than 4 MPa.

  10. Monitoring of suspended sediment variation using Landsat and MODIS in the Saemangeum coastal area of Korea.

    PubMed

    Min, Jee-Eun; Ryu, Joo-Hyung; Lee, Seok; Son, Seunghyun

    2012-02-01

    Suspended sediment concentration (SS) is an important indicator of marine environmental changes due to natural causes such as tides, tidal currents, and river discharges, as well as human activities such as construction in coastal regions. In the Saemangeum area on the west coast of Korea, construction of a huge tidal dyke for land reclamation has strongly influenced the coastal environment. This study used remotely sensed data to analyze the SS changes in coastal waters caused by the dyke construction. Landsat and MODIS satellite images were used for the spatial analysis of finer patterns and for the detailed temporal analysis, respectively. Forty Landsat scenes and 105 monthly composite MODIS images observed during 1985-2010 were employed, and four field campaigns (from 2005 to 2006) were performed to verify the image-derived SS. The results of the satellite data analyses showed that the seawater was clear before the dyke construction, with SS values lower than 20 g/m(3). These values increased continuously as the dyke construction progressed. The maximum SS values appeared just before completion of the fourth dyke. Values decreased to below 5 g/m(3) after dyke construction. These changes indicated tidal current modification. Some eddies and plumes were observed in the images generated from Landsat data. Landsat and MODIS can reveal that coastal water turbidity was greatly reduced after completion of the construction. PMID:22136763

  11. AfricaArray International Geophysics Field School: Applications of Near Surface Geophysics to challenges encountered in mine planning

    NASA Astrophysics Data System (ADS)

    Webb, S. J.; Jones, M. Q.; Durrheim, R. J.; Nyblade, A.; Snyman, Q.

    2012-12-01

    Hard rock exploration and mining presents many opportunities for the effective use of near surface geophysics. For over 10 years the AfricaArray international geophysics field school has been hosted at a variety of mines in South Africa. While the main objective of the field school is practical training for the next generation of geophysicists, being hosted at a mine has allowed us to investigate applications of near surface geophysics in the early stages of mine planning and development as geophysics is often cheaper and faster than drilling. Several applications include: detailed delineation of dykes and stringer dykes, physical property measurements on drill core for modeling and marker horizons, determination of overburden thickness, locations of water and faults. Dolerite dykes are usually magnetic and are associated with loss of ground (i.e. where the dyke replaces the ore and thus reduces the amount of ore available) and safety/stability concerns. Thus the accurate mapping of dykes and narrow stringers that are associated with them are crucial to the safe planning of a mine. We have acquired several case studies where ground magnetic surveys have greatly improved on the resolution and detail of airborne magnetic surveys in regions of complicated dyke swarms. In many cases, thin stringer dykes of less than 5 cm have been detected. Physical property measurements of these dykes can be used to distinguish between different ages of dykes. It is important to accurately determine overburden thickness when planning an open pit mine as this directly affects the cost of development. Depending on the nature of the overburden, both refraction seismic and or DC resistivity can provide continuous profiling in the area of interest that fills in gaps between boreholes. DC resistivity is also effective for determining water associated with dykes and structures that may affect mine planning. The field school mainly addresses the training of a variety of students. The core

  12. Communication between earthquake clusters separated by over 30 km supports simple volcano plumbing

    NASA Astrophysics Data System (ADS)

    Jonsdottir, K.; Jonasson, K.; Gudmundsson, M. T.; Hensch, M.; Hooper, A. J.; Holohan, E. P.; Sigmundsson, F.; Halldorsson, S. A.; Hognadottir, T.; Magnússon, E.; Pálsson, F.; Walter, T. R.; Ofeigsson, B.; Parks, M.; Roberts, M. J.; Hjorleifsdottir, V.; Cesca, S.; Guðmundsson, G.; Hreinsdottir, S.; Jarosch, A. H.; Dumont, S.; Fridriksdóttir, H. M.; Barsotti, S.; Einarsson, P.

    2015-12-01

    The subglacial Bárðarbunga volcano is composed of a large oval caldera (7x11 km) and fissures extending tens of kilometers away from the caldera along the rift zone, which marks the divergent plate boundary across Iceland. On August 16th, 2014 an intense seismic swarm started below the Bárðarbunga caldera and in the two weeks that followed a dyke migrated some 47 km laterally in the uppermost 6-10 km of the crust along the rift. The dyke propagation terminated in lava fields just north of Vatnajökull glacier, where a major (1.5 km3) six months long eruption took place. Intense earthquake activity in the caldera started in the period August 21-24 with over 70 M5 earthquakes accompanying slow caldera collapse, as verified by various geodetic measurements. The subsidence is likely due to magma withdrawal from a reservoir at depth beneath the caldera. During a five months period, October-February, the seismic activity was separated by over 30 km in two clusters; one along the caldera rims (due to piecewise caldera subsidence) and the other at the far end of the dyke (as a result of small shear movements). Here we present statistical analysis comparing the temporal behaviour of seismicity recorded in the two clusters. By comparing the earthquake rate in the dyke in temporal bins before and after caldera subsidence earthquakes to the rate away from these bins (background rate), we show that the number of dyke earthquakes was significantly higher (p <0.05) in the period 0-3 hours before a large earthquake (>M4.6) in the caldera. Increased dyke seismicity was also observed 0-3 hours following a large caldera earthquake. Elevated seismicity in the dyke before a large caldera earthquake may occur when a constriction in the dyke was reduced, followed by pressure drop in the chamber. Assuming that the large caldera earthquakes occurred when chamber pressure was lowest, the subsiding caldera piston may have caused temporary higher pressure in the dyke and thereby increased

  13. Geological structures and geochronology of the Gonam Complex in the Gyeonggi Massif, South Korea

    NASA Astrophysics Data System (ADS)

    Kihm, You Hong; Kim, Sung Won

    2013-04-01

    Geological structures and geochronology of the Gonam Complex in the Gyeonggi Massif, South Korea You Hong Kihm and Sung Won Kim The Gonam complex is exposed in the westernmost part of the Gyeonggi Massif, which is recently thought be related with Triassic collision of China. This complex consists of various lithologies such as quartz schist, mica schist, quartzite, marble, leucocratic granite, mafic dyke and alkali granite. The Gonam complex can be divided into three units from south to north. The first is dominated by alternation of quartz schist and mica schist, which are intruded by leucocratic granites and mafic dykes. The second unit is highly sheared and folded quartzite. The last unit is composed of schists and marble intruded by acidic dykes, mafic dykes and foliated syenite. The deformation of the Gonam complex is characterized by one ductile shearing, two generations of folding, and four generations of faulting. The most prominent geological structures developed in the Gonam Complex are ductile structures, such as mylonitic foliations, mineral stretching lineations, sheath folds and oblique folds. At most outcrops the Gonam Complex was strongly sheared and intruded by amphibolitic dykes and leucocratic granites, which are also sheared. Widely developed mylonite indicates the ductile shearing occurred in high temperature metamorphic condition. SHRIMP zircon ages of detrital zircons obtained from schist and quartzite range from 3313 to 1819 Ma indicating the Gonam Complex deposited after Paleoproterozoic. Intrusion ages of foliated leucocratic granite, mafic dyke and foliated syenite are 821 Ma, 812 Ma and 751 Ma, respectively. And massive mafic dyke, syenite and two-mica granite (232~228 Ma) are interpreted as post-collisional igneous activity. These events are similar to those of Qinling-Dabie Belt and suggest that the Gyeonggi Massif is probably correlated to the Qinling-Dabie Belt.

  14. The difference between oceanic and continental tholeiites: a fluid dynamic explanation

    NASA Astrophysics Data System (ADS)

    Campbell, I. H.

    1985-09-01

    Continental tholeiites have higher SiO2, K2O and light rare earth element contents and more evolved isotopic characteristics than their oceanic counterparts. These differences can be explained if the compositions of the parent magmas to both types of tholeiites are similar but if continental magmas assimilate significant amounts of continental crust en route to the surface. Although there is little doubt that most continental tholeiites have assimilated crustal material, the lcoation and mechanism of assimilation remain uncertain. Longhi (1981) has argued that magmas derived directly from the mantle should crystallize little orthopyroxene. The abundance of orthopyroxene in most continental layered intrusions suggests that they have crystallized from magmas which have assimilated continental crust. Since orthopyroxene is an early crystallizing phase in layered intrusions, this assimilation must occur early, before the magma enters the chamber. Assimilation can occur at the margins of the dykes which feed magma chambers, depending on the nature of the flow. If the flow is turbulent the high temperatures at the centre of the dyke will extend to the margins and the magma will erode the dyke walls. If the flow is laminar, a conductive profile develops at the margin and the flowing magma chills against the walls, protecting them from thermal erosion. The nature of flow in a dyke can be predicted from the Reynolds number, the criteria for turbulence. Reynolds number calculations suggest that the flow of primitive magmas in continental dykes will be fully turbulent and, if this is the case, assimilation of low melting point components in the walls of the dyke is inevitable. It is therefore suggested that many of the geochemical characteristics of continental tholeiites result from melting at the walls of dykes as primitive magmas ascend through the crust.

  15. A Cauldron of Opposition in Duncan's Hometown: Rank-and-File Teachers Score Huge Victory

    ERIC Educational Resources Information Center

    Rethinking Schools, 2010

    2010-01-01

    In a stunning victory, a group of rank-and-file teachers won election to leadership of the powerful Chicago Teachers Union (CTU) this past June. Karen Lewis, a high school chemistry teacher, defeated the two-time incumbent president, winning 60 percent of the vote. Lewis led a slate of candidates from the Caucus of Rank-and-File Educators (CORE),…

  16. 77 FR 11151 - Notice Seeking Comment on the Extractive Industries Transparency Initiative

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... CONTACT: Karen Senhadji; Senior Advisor to the Assistant Secretary for Policy, Management and Budget; 1849..., participatory, and collaborative government; ensure the full and fair return to the American people for the use..., Policy, Management and Budget. BILLING CODE 4310-T2-P...

  17. CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE (CYT19)

    EPA Science Inventory

    CLONING, EXPRESSION, AND CHARACTERIZATION OF RAT S-ADENOSYL-L-METHIONINE: ARSENIC(III) METHYLTRANSFERASE (cyt19)

    Stephen B. Waters1 , Felicia Walton1 , Miroslav Styblo1 , Karen Herbin-Davis2, and David J. Thomas2 1 School of Medicine, University of North Carolina at Chape...

  18. Arsenic methylation phenotype affects accumulation and retention of arsenic in mice

    EPA Science Inventory

    Michael F. Hughes, Brenda C. Edwards, Karen M. Herbin-Davis, David J. Thomas, Pharmacokinetics Branch, ISTD, NHEERL, ORO, US EPA, Research Triangle Park, NC Enzymatically catalyzed methylation of arsenic (As) determines its systemic distribution and retention and its actions as a...

  19. 77 FR 70209 - Designation of Seven Entities Pursuant to Executive Order 13448 or Executive Order 13464 and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ...; Taungngu (Tungoo) Branch, Karen State, Burma . 2. GOLD OCEAN PTE LTD, 101 Cecil Street 08-08, Tong Eng... Cecil Street 08-08, Tong Eng Building, Singapore, 069533, Singapore . 4. GREEN LUCK TRADING COMPANY (a.k..., Singapore 068805, Singapore; 101 Cecil Street, 08-08 Tong Eng Building, Singapore 069533, Singapore;...

  20. Exploratorium: Exploring Water.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2001-01-01

    This issue of Exploratorium focuses on water and its varied uses in our environment. Articles include: (1) "Adventures with Water" (Eric Muller); (2) "Water: The Liquid of Life" (Karen E. Kalumuck); (3) "Water-Drop Projector" (Gorazd Planinsic); (4) "Waterways and Means" (Pearl Tesler); (5) "Explore Natural Phenomena in the Museum--and Just…

  1. Visions in the Dust: A Child's Perspective of the Dust Bowl. Learning Page Lesson Plan.

    ERIC Educational Resources Information Center

    King, Jan; Nisbet, Rena

    Much of history is interpreted from an adult point of view. But in Karen Hesse's Newbery Award-winning "Out of the Dust," the Great Depression's Dust Bowl is seen through the eyes of a child. By using the novel, this lesson plan gives students the opportunity to identify with the personal experiences of youth in the 1930s. In addition, students…

  2. Printers' Devices as Decorative Elements in Library Architecture

    ERIC Educational Resources Information Center

    Nipps, Karen

    2013-01-01

    As has been described in the editorials of the past two issues, "The Library Quarterly" has changed in appearance and content to better reflect contemporary research on library-related issues. As the newly dubbed "History of the Book" editor, Karen Nipps is excited that the cover article segment of the journal is being expanded…

  3. Appraisal of Marist Education in the Light of Patristic Education

    ERIC Educational Resources Information Center

    Osuji, Gregory Ekene; Oluoch-Suleh, Everlyn

    2015-01-01

    The Study evaluated the Marist Brother Lecturer and the Marist Student in Marist International University College, Karen, Nairobi in the light of the Education founded on Christian principles by Jesus Christ and expounded by the early Church Fathers. The Researchers tried to find out the attitude of both Marist Brother Lecturer and Marist Student…

  4. Fitness and Health. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Child Care Information Exchange, 2000

    2000-01-01

    Presents five articles on children's fitness and health: "Relaxation: Every Child's Right to Simply Be" (Patrice Thomas and Wendy Shepherd); "Infant Massage" (Carolyn Oleson); "Fitness and the Young Child" (James M. Poole); "Partners in Health: Helping Families Advocate for Their Children's Health Care" (Karen Sokal-Gutierrez); and "Preventing…

  5. StarBright Learning Exchange

    ERIC Educational Resources Information Center

    Kalinowski, Michael

    2007-01-01

    This article features StarBright Learning Exchange, a program that provides a cross-cultural exchange between Australian and South African early childhood educators. The program was originated when its president, Carol Allen, and her colleague, Karen Williams, decided that they could no longer sit by and watch the unfolding social catastrophe that…

  6. The Future Is Now: The Role of Institutional Research in Campus Transformation: Proceedings of the Annual Conference of the North East Association for Institutional Research (25th, Philadelphia, Pennsylvania, November 14-17, 1998).

    ERIC Educational Resources Information Center

    North East Association for Institutional Research.

    This proceedings document is comprised of the 17 papers, panel presentations, and work shares presented at a 1998 conference on institutional research. The papers are: (1) "Description of the UDAES Project: A Study of Undergraduate Academic Experiences" (Karen W. Bauer); (2) "Transforming Your Campus: Mixed Methodology in Institutional Research"…

  7. The End of Lifelong Learning: A Post-Human Condition?

    ERIC Educational Resources Information Center

    Edwards, Richard

    2010-01-01

    This article explores the significance of theories of the post-human for lifelong learning. Drawing upon the works of Karen Barad and Bruno Latour, it suggests that education has focused on the learning subject as a result of an a priori assumption of a separation of matter from meaning, the object from the subject. By contrast, a post-human…

  8. On a Quest for Principles, Big Data in Hand.

    PubMed

    2016-05-19

    Cell editor Karen Carniol discusses the excitement and challenges of the "big data" era and how quantitative approaches reveal important biological principles with Galit Lahav, Gürol Süel, and Olga Troyanskaya. Annotated excerpts from this conversation are presented below, and the full conversation is available with the article online. PMID:27203104

  9. 77 FR 13123 - Cross-Media Electronic Reporting: Authorized Program Revision Approval, State of Ohio

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ..., seeh.karen@epa.gov . SUPPLEMENTARY INFORMATION: On October 13, 2005, the final Cross-Media Electronic Reporting Rule (CROMERR) was published in the Federal Register (70 FR 59848) and codified as part 3 of title... AGENCY Cross-Media Electronic Reporting: Authorized Program Revision Approval, State of Ohio...

  10. Cognitive Science.

    ERIC Educational Resources Information Center

    Soni, P. Sarita, Ed.; Carmichael, Ann G., Ed.

    1993-01-01

    This theme issue features five articles profiling Indiana University faculty whose work on various campuses continues to broaden and advance knowledge about cognitive science. The articles in the journal are: "A Matter of Time" (Karen Grooms) which discusses the work of Robert F. Port; "Perceiving as a Complex System" (Tom Tierney) which profiles…

  11. College, Country, Church. 1789-1989.

    ERIC Educational Resources Information Center

    Current Issues in Catholic Higher Education, 1989

    1989-01-01

    A collection of papers on current issues in Catholic higher education is presented. Papers are as follows: "Introduction" (Alice Gallin); "Changing and Remaining the Same: A Look at the Record" (Philip Gleason); "Catholic Women's Colleges: A Review of the Record" (Karen M. Kennelly); "A Weight to Our Establishment: Georgetown University and the…

  12. Children and Media outside the Home: Playing and Learning in After-School Care

    ERIC Educational Resources Information Center

    Vered, Karen Orr

    2008-01-01

    Karen Orr Vered demonstrates how children's media play contributes to their acquisition of media literacy. Theorizing after-school care as intermediary space, a large-scale ethnographic study informs this theory-rich and practical discussion of children's media use beyond home and classroom.

  13. Culture, Context, and Innovation: A Kiwi Canuck Perspective

    ERIC Educational Resources Information Center

    Marshall, Dave; Shaver, Karen

    2010-01-01

    This commentary lends a global practitioner perspective on the utility of this volume to the efforts of mentors and mentees and mentoring program developers. Dave Marshall and Karen Shaver, of Big Brothers Big Sisters New Zealand and Canada, respectively, offer keen insights into the value of creating a shared language for discussing mentoring…

  14. 75 FR 60125 - SES Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... Performance Review Board AGENCY: Federal Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given of the appointment of members to the FTC Performance Review Board. FOR FURTHER INFORMATION CONTACT: Karen.... ] SUPPLEMENTARY INFORMATION: Publication of the Performance Review Board (PRB) membership is required by 5...

  15. 76 FR 9401 - Notice of Meeting of the National Parks Overflights Advisory Group Aviation Rulemaking Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ...) and the National Park Service (NPS), in accordance with the National Parks Air Tour Management Act of... National Parks Air Tour Management Act of 2000 (NPATMA), enacted on April 5, 2000, as Public Law 106-181... 90009-2007, telephone: (310) 725-3800, e-mail: Barry.Brayer@faa.gov , or Karen Trevino, National...

  16. 77 FR 64967 - Senior Executive Service; Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-24

    ..., KAREN C HALE, ANDREW M HALE, JOHN H HALLMAN, TIMOTHY J HANDWERKER, ALAN I HANLON, PETER H HANNIGAN... HARRIS, ROBERT J HARROD, WILLIAM J HARVEY, STEPHEN J HELD, EDWARD B HENDERSON III, CLYDE H HENNEBERGER..., LINDA S KIRCHHOFF, STEPHEN A KLARA, SCOTT M KLAUSING, KATHLEEN A KLING, JON NMN KNOELL, THOMAS C...

  17. MinneTESOL/WITESOL Journal, 2000-2001.

    ERIC Educational Resources Information Center

    Upton, John, Ed.

    2001-01-01

    These two journal issues present articles on the following: "Understanding and Teaching American Cultural Thought through English Metaphors" (Carl Zhonggang Gao); "An Alternative Model for Novice-Level Elementary ESL Education" (Karen Duke, Ann Mabbott); "Wisconsin's Approach to Academic Assessment for Limited-English Proficient Students (LEP):…

  18. STS-124 crew visits Stennis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's John C. Stennis Space Center Deputy Director Gene Goldman (center) welcomed members of the STS-124 Discovery space shuttle crew during their July 23 visit to the center. Crew members who visited Stennis were (l to r) Pilot Ken Ham, Mission Specialist Karen Nyberg, Kelly, and Mission Specialists Ron Garan and Mike Fossum.

  19. A Guide to Using State Longitudinal Data for Applied Research. NCEE 2015-4013

    ERIC Educational Resources Information Center

    Levesque, Karen; Fitzgerald, Robert; Pfeiffer, Jay

    2015-01-01

    State longitudinal data systems (SLDSs) promise a rich source of data for education research. SLDSs contain statewide student data that can be linked over time and to additional data sources for education management, reporting, improvement, and research, and ultimately for informing education policy and practice. Authored by Karen Levesque, Robert…

  20. What's Good about the Best?

    ERIC Educational Resources Information Center

    Hipple, Ted; Maupin, Amy B.

    2001-01-01

    Discusses three award-winning novels for young adults that are very popular with school teachers: "The Giver" by Lois Lowry, "Out of the Dust" by Karen Hesse, and "Holes" by Louis Sachar. Examines the quality of plots, characters, and themes but also considers the artistry in details and emotional impact. Offers suggestions for teaching these…

  1. Planning for Proficiency. Dimension: Language '86. Report of the Southern Conference on Language Teaching (1986).

    ERIC Educational Resources Information Center

    Fryer, T. Bruce; Medley, Frank W., Jr.

    Selected papers from the 1986 Southern Conference on Language Teaching on instruction for language proficiency are presented: "The Foreign Language Teacher: Confronting an Ever-Changing Profession" (Robert Di Donato); "Restructuring a Traditional Foreign Language Program for Oral Proficiency" (Filisha Camara-Norman, James Davis, Karen Smyley…

  2. Commensal Bacteria Control Cancer Response to Therapy by Modulating the Tumor Microenvironment | Poster

    Cancer.gov

    Noriho Iida, Amiran Dzutsev, C. Andrew Stewart, Loretta Smith, Nicolas Bouladoux, Rebecca A. Weingarten, Daniel A. Molina, Rosalba Salcedo, Timothy Back, Sarah Cramer, Ren-Ming Dai, Hiu Kiu, Marco Cardone, Shruti Naik, Anil K. Patri, Ena Wang, Francesco M. Marincola, Karen M. Frank, Yasmine Belkaid, Giorgio Trinchieri, Romina S. Goldszmid Science 342(6161):967-970, 2013

  3. Creating Start-up Companies around NCI Inventions | Poster

    Cancer.gov

    By Karen Surabian, Thomas Stackhouse, and Rose Freel, Contributing Writers, and Rosemarie Truman, Guest Writer The National Cancer Institute (NCI), led by the Technology Transfer Center (TTC),  the Avon Foundation, and The Center for Advancing Innovation have partnered to create a “first-of-a-kind” Breast Cancer Start-up Challenge.

  4. The Children's Education Project: Tham Hin Refugee Camp, Thailand

    ERIC Educational Resources Information Center

    Olesen, Mavis L.

    2004-01-01

    In 1997, twelve Karen Burmese teachers brought a Vision Paper to the Tham Hin refugee camp in Thailand. The teachers had recently written this Paper after much consultation with their Mergui-Tavoy villagers, students, leaders, and school dropouts. Over the following five years teams developed a project outlining 10 steps to educational reform,…

  5. Language, Gesture, and Space.

    ERIC Educational Resources Information Center

    Emmorey, Karen, Ed.; Reilly, Judy S., Ed.

    A collection of papers addresses a variety of issues regarding the nature and structure of sign language, gesture, and gesture systems. Articles include: "Theoretical Issues Relating Language, Gesture, and Space: An Overview" (Karen Emmorey, Judy S. Reilly); "Real, Surrogate, and Token Space: Grammatical Consequences in ASL American Sign Language"…

  6. The Materiality of Fieldwork: An Ontology of Feminist Becoming

    ERIC Educational Resources Information Center

    Childers, Sara M.

    2013-01-01

    Through the materiality of fieldwork at a high-achieving high-poverty high school, I discuss how the collision between practices of feminist methodology and the materiality of fieldwork forced me to rethink the "feminist" in feminist research. Using the work of Karen Barad, this material-discursive account of methodology as ontology…

  7. Forum for Reading: The Journal for Two-Year College Reading Teachers. Volume 6, No. 2, April, 1977.

    ERIC Educational Resources Information Center

    Pinette, Clayton A., Ed.; Smith, R. Kent, Ed.

    Five articles concerning college reading instruction are included in this special interest journal. Karen L. Pelz, William E. Pelz, and David L. Stritmater present a study of input sequence, exposure, and modality effects on recognition memory, which revealed that students who read assignments and attended lectures performed better on tests on the…

  8. Fostering Teacher Learning through Collaborative Inquiry

    ERIC Educational Resources Information Center

    Goodnough, Karen

    2005-01-01

    In this article, the author describes a project in which Collaborative Inquiry, or CI (Bray et al. 2000), was used by a small inquiry group consisting of a high school science teacher and two university educators, Marie Cashion and the author herself, Karen Goodnough, to explore Problem-Based Learning (PBL). In CI groups, co-learners work through…

  9. Hiring the Next Generation of Faculty. New Directions for Community Colleges, Number 152

    ERIC Educational Resources Information Center

    Cejda, Brent D., Ed.; Murray, John P., Ed.

    2011-01-01

    This volume contains the following papers: (1) Preparing to Hire the Best in the Perfect Storm (John P. Murray); (2) New Faculty Issues: Fitting In and Figuring It Out (Pamela L. Eddy); (3) An Approach to a Faculty Professional Development Seminar (Mary Bendickson and Karen Griffin); (4) Faculty Issues in Rural Community Colleges (Brent D. Cejda);…

  10. Bullying Prevention for School Safety (with Related Video)

    ERIC Educational Resources Information Center

    Johnson, Katie

    2012-01-01

    The nation watched in shock recently as four middle school boys barraged 68-year-old bus monitor Karen Klein with jabs about her weight, attacks on her family, and chuckled as they made violent and graphic threats. Klein remained quiet, taking the abuse and failing to respond to the students. This incident might have gone unnoticed and unreported,…

  11. Foundation for Child Development Annual Report, 2001-2002.

    ERIC Educational Resources Information Center

    Foundation for Child Development, New York, NY.

    This annual report details the activities of the Foundation for Child Development (FCD) for 2001-2002. Beginning the report is a brief description of the Foundations mission, its funding priorities, and application procedures. The report then presents the joint statement of the chair, Karen Gerard, and the president, Ruby Takanishi, focusing on…

  12. The Role of Built Environments in Physical Activity, Eating, and Obesity in Childhood

    ERIC Educational Resources Information Center

    Sallis, James F.; Glanz, Karen

    2006-01-01

    Over the past forty years various changes in the U.S. "built environment" have promoted sedentary lifestyles and less healthful diets. James Sallis and Karen Glanz investigate whether these changes have had a direct effect on childhood obesity and whether improvements to encourage more physical activity and more healthful diets are likely to lower…

  13. Intercultural Communications Skills Conference Proceedings (Townsville, Queensland, Australia, July 1-3, 1990).

    ERIC Educational Resources Information Center

    Migrant Resource Centre, Townsville (Australia).

    This document contains 11 papers presented at a conference on multicultural issues such as cultural identity, stereotyping, and verbal and nonverbal communication: "Intercultural Communication--An Overview" (Karen Dennien); "Cultural Identity, Communication and Community Relations" (Lyn Trad); "Immigration to Australia" (Mary Woods); "Culturally…

  14. A NOVEL S-ADENOSYL-L-METHIONINE: ARSENIC (III) METHYLTRANSFERASE FROM RAT LIVER CYTOSOL

    EPA Science Inventory

    A Novel S-Adenosyl-L-methionine: Arsenic(III) Methyltransferase from Rat Liver Cytosol
    Shan Lin, Qing Shi, F. Brent Nix, Miroslav Styblo, Melinda A. Beck, Karen M. Herbin-Davis, Larry L. Hall, Josef B. Simeonsson, and David J. Thomas
    S-adenosyl-L-methionine (AdoMet): ar...

  15. A Collectibles Project: Engaging Students in Authentic Multimodal Research and Writing

    ERIC Educational Resources Information Center

    Moynihan, Karen E.

    2007-01-01

    High school teacher Karen E. Moynihan creates a multimodal project inspired by the creative nonfiction style of "The Orchid Thief" by Susan Orlean. Students choose a collectible item and immerse themselves in the subculture of the collectors. The project includes participation in library and field research, interviews, photography and graphic…

  16. METHODS TO EVALUATE ARSENIC BIOAVAILABILITY ASSOCIATED WITH THE PRESENCE OF CCA-TREATED WOOD PRODUCTS

    EPA Science Inventory

    This is an invited paper to be presented by Dr. Karen Bradham at the 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, Australia, April 3 - 7, 2005. The abstract describes methods to evaluate arsenic bioavailability associated with the presence of ...

  17. ARSENIC BIOAVAILABILITY ASSOCIATED WITH THE PRESENCE OF CCA-TREATED WOOD PRODUCTS

    EPA Science Inventory

    This is an invited paper/slide presentation to be presented by Dr. Karen Bradham at the 8th International Conference on the Biogeochemistry of Trace Elements, Adelaide, Australia, April 3 - 7, 2005. The PowerPoint slides describe the study design of projects currently being perf...

  18. Getting the Green: Fundraising Campaigns for Community Colleges

    ERIC Educational Resources Information Center

    Grover, Stuart R.

    2009-01-01

    This book offers a comprehensive and detailed look at private fundraising in community colleges. In the foreward, Karen A. Stout, President, Montgomery County Community College, describes it as a "must-read" for aspiring and new community college presidents, academic leaders searching for ways to bring in new dollars to support new programs, and…

  19. LINWORTH/ALISE 2009 Youth Services Paper: Equal Opportunity? Poverty and Characteristics of School Library Media Centers

    ERIC Educational Resources Information Center

    Pribesh, Shana; Gavigan, Karen

    2009-01-01

    When the authors met through a mutual colleague, Gail Dickinson at Old Dominion University, Karen and Shana set about to examine issues that do not normally interest sociologists--the number of days school libraries are closed and whether or not library schedules (fixed or flexed) impact student achievement. However, Shana, a sociologist who…

  20. 78 FR 38203 - Refunds and Exchanges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ... of proposed rulemaking on March 14, 2013 (78 FR 16213), which included a 30 day comment period. After... Key, Shipping Products, karen.f.key@usps.gov , 202-268-2282; Suzanne Newman, Product Classification... Classification Service Center (see 608.8.0), who issues the final agency decision. Refunds for postage...

  1. Leveraging Information Technology. Track IV: Support Services.

    ERIC Educational Resources Information Center

    CAUSE, Boulder, CO.

    Seven papers from the 1987 CAUSE conference's Track IV, Support Services, are presented. They include: "Application Development Center" (John F. Leydon); "College Information Management System: The Design and Implementation of a Completely Integrated Office Automation and Student Information System" (Karen L. Miselis); "Improving Managerial…

  2. Information Literacy and its Relationship to Cognitive Development and Reflective Judgment

    ERIC Educational Resources Information Center

    Jackson, Rebecca

    2008-01-01

    This article maps the Association of College and Research Libraries' Information Competency Standards for Higher Education to the cognitive development levels developed by William G. Perry and Patricia King and Karen Kitchener to suggest which competencies are appropriate for which level of cognitive development. (Contains 1 table.)

  3. Applying Brain Research. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Stephens, Karen; Schiller, Pam; Phipps, Pat; O'Donnell, Nina Sazer

    1999-01-01

    Four articles discuss recent findings on early brain development, describe classroom applications for specific findings, and include a brain compatibility evaluation: (1) "Primed for Learning: The Young Child's Mind" (Karen Stephens); (2) "Turning Knowledge into Practice" (Pam Schiller); (3) "Is Your Program Brain Compatible?" (Pat Phipps); and…

  4. Travel in Time: Tradition to Technology. Proceedings of the 1985 ABC International Convention (Chicago, Illinois, October 1985).

    ERIC Educational Resources Information Center

    Bruno, Sam J., Ed.; Pettit, John D., Jr., Ed.

    These conference proceedings contain the following 23 presentations: "Development of a Communication Skill Model Using Interpretive Structural Modeling" (Karen S. Nantz and Linda Gammill); "The Coincidence of Needs: An Inventional Model for Audience Analysis" (Gina Burchard); "A Computer Algorithm for Measuring Readability" (Terry D. Lundgren);…

  5. Higher Education: Handbook of Theory and Research. Volume VII.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Eleven papers on theory and research in higher education have the following titles and authors: "Perceived Control in College Students: Implications for Instruction in Higher Education" (Raymond P. Perry); "The Changing Locus of Control Over Faculty Research: From Self-Regulation to Dispersed Influence" (Melissa S. Anderson and Karen Seashore…

  6. Multiculturalism in Developmental Education. CRDEUL Monograph.

    ERIC Educational Resources Information Center

    Higbee, Jeanne L., Ed.; Lundell, Dana Britt, Ed.; Duranczyk, Irene M., Ed.

    This collection of papers is intended to help make connections between multicultural education and developmental education. The papers include an introduction by Jeanne L. Higbee and: "The Centrality of Multiculturalism in Developmental Education" (Karen L. Miksch, Patrick L. Bruch, Jeanne L. Higbee, Rashne R. Jehangir, and Data Britt Lundell);…

  7. Bridges to the Future: Building Linkages for Institutional Research. North East Association for Institutional Research Annual Conference Proceedings (27th, Pittsburgh, PA, November 4-7, 2000).

    ERIC Educational Resources Information Center

    North East Association for Institutional Research.

    This document contains papers, summaries of panel presentations, and work share meetings from the annual conference of the North East Association for Institutional Research. The papers are: (1) "The Influence of Personality Traits, Pre-College Characteristics, and Co-Curricular Experiences on College Outcomes" (Karen W. Bauer); (2) "Threading the…

  8. New Materialist Ontologies in Mathematics Education: The Body in/of Mathematics

    ERIC Educational Resources Information Center

    de Freitas, Elizabeth; Sinclair, Nathalie

    2013-01-01

    In this paper we study the mathematical body as an assemblage of human and non-human mathematical concepts. We argue that learners' bodies are always in the process of becoming assemblages of diverse and dynamic materialities. Following the work of the historian of science Karen Barad, we argue that mathematical concepts must be considered dynamic…

  9. 78 FR 73868 - Privacy Act of 1974; Department of Homeland Security Transportation Security Administration-DHS...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... August 4, 2006 in 71 FR 44223. This updated system will be included in DHS' inventory of record systems.... Electronic access is limited by computer security measures that are strictly enforced. TSA file areas are... rule published on August 4, 2006 in 71 FR 44223. Dated: November 21, 2013. Karen L. Neuman...

  10. Understanding the Business of Library Acquisitions. Second Edition.

    ERIC Educational Resources Information Center

    Schmidt, Karen A., Ed.

    This expanded edition provides new information about successfully managing library acquisitions. Chapters include: "Acquisitions, the Organization, and the Future" (Carol Pitts Diedrichs and Karen A. Schmidt); "The Business of Book Publishing" (Patricia Glass Schuman and Charles Harmon); "The Business of Scholarly Journal Publishing" (Gary J.…

  11. The Role of Schools in Obesity Prevention

    ERIC Educational Resources Information Center

    Story, Mary; Kaphingst, Karen M.; French, Simone

    2006-01-01

    Mary Story, Karen Kaphingst, and Simone French argue that U.S. schools offer many opportunities for developing obesity-prevention strategies by providing more nutritious food, offering greater opportunities for physical activity, and providing obesity-related health services. Meals at school are available both through the U.S. Department of…

  12. 78 FR 77125 - Senior Executive Service Performance Review Board; Membership

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... AGENCY Senior Executive Service Performance Review Board; Membership AGENCY: U.S. Environmental.... Environmental Protection Agency Performance Review Board for 2013. FOR FURTHER INFORMATION CONTACT: Karen D... Personnel Management, one or more SES performance review boards. This board shall review and evaluate...

  13. 78 FR 9762 - Self-Regulatory Organizations; The Depository Trust Company; Notice of Designation of a Longer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... (Dec. 28, 2012), 78 FR 795 (Jan. 4, 2013). \\4\\ See Comment from Karen Jackson dated December 30, 2012... of Maturity and Income Presentments and Issuances of Money Market Instruments February 5, 2013. On... DTC's processing of maturity and income presentments and issuances of money market instruments....

  14. Humor. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Elkind, David; Parr, Jerry; Duffy, Vincent; Strader, Bill; Stephens, Karen

    2000-01-01

    Presents five articles on humor in early child care: (1) "What Makes Young Children Laugh?" (David Elkind); (2) "Humor as a Tool in the Workplace" (Jerry Parr); (3) "Vincent's Vignettes" (Vincent Duffy); (4) "Family Humor" (Bill Strader); and (5) "Books to Tickle Funny Bones" (Karen Stephens). (SD)

  15. 78 FR 51234 - Sunshine Act Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... August 26, 2013 2:00 p.m. Discussion of Management and Personnel Issues (Closed--Ex. 2 and 6). Tuesday, August 27, 2013 9:00 a.m. Briefing on NRC's Construction Activities (Public Meeting); (Contact: Michelle....m. Briefing on NRC International Activities (Closed--Ex. 1 & 9) (Contact: Karen Henderson,...

  16. Thirty-Five Years of Studying Work and Family

    ERIC Educational Resources Information Center

    Brett, Jeanne M.

    2011-01-01

    The author and Karen Gyllstrom began working on the study that resulted in the highly cited article entitled, "Working Men and Women: Inter-and Intra-role Conflict" (Herman & Gyllstrom, "Psychology of Women Quarterly" 1977) probably more for personal than professional reasons. The study was based on Gyllstrom's master's thesis. The focus of…

  17. Changing and/or Reinscribing Gendered Discourses of Team Leadership in Education?

    ERIC Educational Resources Information Center

    Court, Marian

    2007-01-01

    In this article, prevailing professional, business and managerial discourses of team leadership are "troubled" by some feminist critiques and analyses of collectivity and gendered discursive relations of power. I draw on a study of primary school co-principalships to describe and reflect on Karen's (a pseudonym) accounts of her personal and shared…

  18. 75 FR 8187 - Qualification of Drivers; Exemption Renewals; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... at the end of the 2-year period. The comment period ended on January 11, 2010 (74 FR 65845... Thomas E. Anderson, Garry A. Baker, Bruce W. Barrett, Richard D. Becotte, Wayne Burnett, Theodore W. Cozat, Alex G. Dlugolenski, Karen Y. Duvall, Nigel L. Farmer, Gordon R. Fritz, John A. Graham, Jimmy...

  19. Registering Researchers in Authority Files

    ERIC Educational Resources Information Center

    Smith-Yoshimura, Karen; Altman, Micah; Conlon, Michael; Cristán, Ana Lupe; Dawson, Laura; Dunham, Joanne; Hickey, Thom; Hook, Daniel; Horstmann, Wolfram; MacEwan, Andrew; Schreur, Philip; Smart, Laura; Wacker, Melanie; Woutersen, Saskia

    2014-01-01

    Written by OCLC Research Program Officer Karen Smith-Yoshimura and the 13 members of the Registering Researchers in Authority Files Task Group comprised of specialists from the US, UK, and the Netherlands, this report summarizes their research into approaches to providing authoritative researcher identifiers. Registering researchers in some type…

  20. New Website Helps You Find What You Need | Poster

    Cancer.gov

    By Karen Surabian, Contributing Writer The National Cancer Institute’s Technology Transfer Center (NCI’s TTC) recently launched a redesign of its website. New graphics, color scheme, and updated features provide a user-friendly environment for finding information related to technology transfer at NCI.

  1. Focus on Basics, 1997.

    ERIC Educational Resources Information Center

    Focus on Basics, 1997

    1997-01-01

    Together, these four newsletters contain 36 articles devoted to adult literacy research and practice and the relationship between them. The following articles are included: "A Productive Partnership" (Richard J. Murnane, Bob Bickerton); "Welcome to 'Focus on Basics'" (Barbara Garner); "Applying Research on the Last Frontier" (Karen Backlund, Kathy…

  2. What Then Are We to Say about These Things?

    ERIC Educational Resources Information Center

    Japinga, Jeffrey; DeMoor, Robert

    2003-01-01

    In this article, the authors discuss Karen Cross's critique on LiFE (Living in Faith Everyday) curriculum. Cross's critique focuses on the following issues: (1) racism; (2) sexism; (3) classism; (4) suburbanism; (5) Reformed theology; and (6) method. To respond to Cross's critique is an invitation for everyone to examine not only one particular…

  3. Culture, Relevance, and Schooling: Exploring Uncommon Ground

    ERIC Educational Resources Information Center

    Scherff, Lisa, Ed.; Spector, Karen, Ed.

    2011-01-01

    In "Culture, Relevance, and Schooling: Exploring Uncommon Ground," Lisa Scherff, Karen Spector, and the contributing authors conceive of culturally relevant and critically minded pedagogies in terms of opening up new spatial, discursive, and/or embodied learning terrains. Readers will traverse multiple landscapes and look into a variety of spaces…

  4. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (84th, Washington, DC, August 5-8, 2001). Law Division.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The Law section of the proceedings contains the following 6 selected papers: "Is the Public Interest Meaningless? Levels of Meaning and Ambiguity in the Public Interest Standard" (Philip M. Napoli); "An 'Unholy Alliance': The Law of Media Ride-Alongs" (Karen M. Markin); "Is Internet Service Provider Immunity Growing? An Examination of Immunity…

  5. 78 FR 70027 - Senior Executive Service; Performance Review Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-22

    .... ANDERSON, CYNTHIA V. ANDERSON, ROBERT T. ANDREWS, CLAUDIA R. AOKI, STEVEN NMN ARANGO III, JOSEPH NMN..., TRACEY L. BLACK, STEVEN K. BOARDMAN, KAREN L. BODI, F. LORRAINE BOLTON JR. EDWARD L. BORGSTROM, CAROL M... R. CRAWFORD, GLEN D. CRESCENZO, FRANK J. CROUTHER, DESI A. CROWELL, BRADLEY R. CUGINI, ANTHONY...

  6. The Role of Child Care Settings in Obesity Prevention

    ERIC Educational Resources Information Center

    Story, Mary; Kaphingst, Karen M.; French, Simone

    2006-01-01

    Mary Story, Karen Kaphingst, and Simone French argue that researchers and policymakers focused on childhood obesity have paid insufficient attention to child care. Although child care settings can be a major force in shaping children's dietary intake, physical activity, and energy balance--and thus in combating the childhood obesity…

  7. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (74th, Boston, Massachusetts, August 7-10, 1991). Part I: Media and Law, Section A.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    Section A of the Media and Law section of these proceedings contains the following 11 papers: "The Record of the Rehnquist Court on Freedom of Expression" (F. Dennis Hale); "An Examination of the FCC's Minority and Gender Licensing Policies" (Howard Kleiman); "Exploring the Possibilities of an International Right of Correction" (Karen E. Kline);…

  8. Chronicle of Higher Education. Volume 51, Number 31, April 8, 2005

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2005

    2005-01-01

    "Chronicle of Higher Education" presents an abundant source of news and information for college and university faculty members and administrators. This April 8, 2005 issue of "Chronicle for Higher Education" includes the following articles: (1) "Words Worth Their Weight in Cash" (Markin, Karen); (2) "Diary of a Joint Search, Part 3"; (3) "The…

  9. Flexible Models for Learning English Are Needed for Refugee Mothers

    ERIC Educational Resources Information Center

    Riggs, Elisha; Block, Karen; Gibbs, Lisa; Davis, Elise; Szwarc, Josef; Casey, Sue; Duell-Piening, Philippa; Waters, Elizabeth

    2012-01-01

    The importance of English language acquisition for resettlement of refugees is well established, particularly as a pathway to education, employment, health and social connections. A qualitative study was conducted in 2011 in Melbourne, Australia utilising focus groups with 87 refugee background women from Karen, Iraqi, Assyrian Chaldean, Lebanese,…

  10. The Complex World of Adolescent Literacy: Myths, Motivations, and Mysteries

    ERIC Educational Resources Information Center

    Moje, Elizabeth Birr; Overby, Melanie; Tysvaer, Nicole; Morris, Karen

    2008-01-01

    In this article, Elizabeth Birr Moje, Melanie Overby, Nicole Tysvaer, and Karen Morris challenge some of the prevailing myths about adolescents and their choices related to reading. The reading practices of youth from one urban community are examined using mixed methods in an effort to define what, how often, and why adolescents choose to read. By…

  11. Proceedings of the Annual Mid-South Instructional Technology Conference (6th, Murfreesboro, Tennessee, April 8-10, 2001).

    ERIC Educational Resources Information Center

    Middle Tennessee State Univ., Murfreesboro.

    This proceedings of the sixth annual Mid-South Instructional Technology Conference contains the following papers: "They're Not Just Big Kids: Motivating Adult Learners" (Karen Jarrett Thoms); "A Computer Integrated Biology Laboratory Experience" (James B. Kring); "Building Web Sites for Mathematics Courses: Some Answers to Notation Problems"…

  12. Economic Education Experiences of Enterprising Teachers. Volume 31.

    ERIC Educational Resources Information Center

    Nappi, Andrew T., Ed.

    This book describes award-winning teacher-developed projects and courses in economics. The reports are condensed versions of the original projects and are divided into grade levels. Primary Level includes: "Primary Pickle People Packed a Peck of Pickle Economics" (Karen L. Cragg; Katherine J. Van Horn); "Fabulous Economics" (Elizabeth B.…

  13. 77 FR 38288 - Ocean Transportation Intermediary License; Applicants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... Commerce Park Drive, Suite E, Marietta, GA 30060. Officers: Cornelius U. Odinjor, President/CEO (Qualifying.... Romine, President (Qualifying Individual). Ron ] Cain, CEO. Application Type: Trade Name Change and QI... Lee, CEO/President. Application Type: New NVO License. Dated: June 22, 2012. Karen V....

  14. A Leader's Top Task Is to Nurture Talent

    ERIC Educational Resources Information Center

    Louis, Karen Seashore

    2016-01-01

    In her full essay exploring the Leadership standard in "Reach the Highest Standard in Professional Learning: Leadership," author Karen Seashore Louis offers keen insights into the question of how leaders affect the learning of other adults in a school. She writes particularly about how "school leaders can create a school culture in…

  15. Astronaut Richard H. Truly in training session RMS for STS-2 bldg 9A

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Astronaut Richard H. Truly in training session with the Remote Manipulator System (RMS) for STS-2 bldg 9A. Views show Truly working at the command console while watching out the windows. Karen Ehlers, an RMS procedures specialist, can be seen at left side of frame (34314); view from behind Truly as he trains at the RMS console (34315).

  16. Metahistory: A Review Essay.

    ERIC Educational Resources Information Center

    Musselwhite, Laura

    2000-01-01

    Reviews three works that each examine a specific area of metahistory: (1) "World Historians and their Goals" by Paul Costello; (2) "The Structure of Big History" by Fred Spier; and (3) "The Myth of Continents" by Martin Lewis and Karen Wigen. (CMK)

  17. 77 FR 51101 - Minnesota Disaster #MN-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    .../2012. Incident: Severe storms and flooding. Incident Period: 06/14/2012 through 06/21/2012. Effective Date: 08/16/2012. Physical Loan Application Deadline Date: 10/15/2012. Economic Injury (EIDL) Loan... 59002 and 59008) Dated: August 16, 2012. Karen G. Mills, Administrator. BILLING CODE 8025-01-P...

  18. 77 FR 51100 - Tennessee Disaster #TN-00068

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    .../2012. Incident: Severe storms, flooding and heavy rain. Incident Period: 08/05/2012 through 08/06/2012. Effective Date: 08/16/2012. Physical Loan Application Deadline Date: 10/15/2012. Economic Injury (EIDL) Loan...) Dated: August 16, 2012. Karen G. Mills, Administrator. BILLING CODE 8025-01-P...

  19. Working To Learn: Transforming Learning in the Workplace.

    ERIC Educational Resources Information Center

    Evans, Karen, Ed.; Hodkinson, Phil, Ed.; Unwin, Lorna, Ed.

    This book contains 13 papers on transformations in the nature of work that affect the learning and skill requirements of jobs and individuals and ways those requirements can be met. The following papers are included: "The Significance of Workplace Learning for a 'Learning Society'" (Karen Evans, Helen Rainbird); "Learning Careers: Conceptualizing…

  20. 75 FR 69435 - Public Water System Supervision Program Revision for the State of North Dakota

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... Administrator, c/o Karen Shirley (8P-W-DW), U.S. EPA, Region 8, 1595 Wynkoop Street, Denver, CO 80202-1129. All.... EPA, Region 8, Drinking Water Program, 1595 Wynkoop Street, Denver, CO 80202-1129, (2) North...

  1. 76 FR 58716 - Telemarketing Sales Rule

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-22

    ..., 2011. FOR FURTHER INFORMATION CONTACT: Karen S. Hobbs, Attorney, Division of Marketing Practices... Register on August 10, 2010 (75 FR 48458), with new provisions to address the telemarketing of debt relief... From the Federal Register Online via the Government Publishing Office FEDERAL TRADE COMMISSION...

  2. Bringing Technology to the Issues. Proceedings of the North East Association for Institutional Research Conference (16th, Pittsburgh, Pennsylvania, October 21-24, 1989).

    ERIC Educational Resources Information Center

    1989

    The conference program and the texts of 24 papers presented at the conference are provided in this document. Selected papers include: "The Use of the College Student Experience Questionnaire in Policy and Program Development" (Karen Bauer and Dale Trusheim); "Predicting Freshman Performance as Admissions Criteria" (David Zubrow); "Has the Middle…

  3. Navigating the Literacy Waters: Research, Praxis, and Advocacy. The Twenty-Ninth Yearbook: A Peer Reviewed Publication of the College Reading Association. [Papers from the College Reading Association Conference, 2006

    ERIC Educational Resources Information Center

    Foote, Martha M., Ed.; Szabo, Susan, Ed.; Falk-Ross, Francine, Ed.; Sampson, Mary Beth, Ed.

    2008-01-01

    This book presents a selection of the research and papers presented at the 50th Annual Meeting of the College Reading Association in Pittsburgh, Pennsylvania in October, 2006. This Yearbook begins with Karen Bromley's presidential address, which explored the future of writing by discussing four predictions: the notion that pens and pencils will be…

  4. Health Occupations Education. Biennial National Health Occupations Research Conference Proceedings. (5th, Nashville, Tennessee, December 1, 1993).

    ERIC Educational Resources Information Center

    Rzonca, Chet, Ed.

    These proceedings include the agenda of the conference, a list of its cosponsors, and the texts of the following six papers presented at the conference: "Hepatitis Vaccine: Are Health Occupations Education Students Protected?" (Cynthia Chappelka); "Integrated Academics: An HOE Model" (Karen E. Gable, Beverly Ransdell); "The Ability of Work Related…

  5. Sprog, kultur, intersprog (Language, Culture, Interlanguage). ROLIG-Papir 57.

    ERIC Educational Resources Information Center

    Risager, Karen, Ed.

    Four articles on language, culture, and interlanguage are included in this volume. The first by Karen Risager, "Sprog, kultur, og internationalisering" ("Language, Culture, and Internationalization") takes issue with the very broad perception that foreign language and culture cannot be separated in instruction. The second article,…

  6. "Effects Of" and "Effects With" Captions: How Exactly Does Watching a TV Programme with Same-Language Subtitles Make a Difference to Language Learners?

    ERIC Educational Resources Information Center

    Vanderplank, Robert

    2016-01-01

    Ever since Karen Price's ground-breaking work in 1983, we have known that same-language subtitles (captions) primarily intended for the deaf and hearing-impaired can provide access to foreign language films and TV programmes which would otherwise be virtually incomprehensible to non-native-speaker viewers. Since then, researchers have steadily…

  7. Chronicle of Higher Education. Volume 51, Number 15, December 3, 2004

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 2004

    2004-01-01

    "Chronicle of Higher Education" presents an abundant source of news and information for college and university faculty members and administrators. This December 3, 2004 issue of "Chronicle for Higher Education" includes the following articles: (1) "For Student-Loan Borrowers, Good Credit Where It's Due" (Gross, Karen); (2) "Redemption and American…

  8. Making Biology Relevant to Undergraduates

    ERIC Educational Resources Information Center

    Musante, Susan

    2012-01-01

    This article features Science Education for New Civic Engagements and Responsibilities (SENCER; www.sencer.net) Summer Institute. The SENCER program, which began formally in 2001, was the vision of David Burns; Karen Oates, currently Peterson Family Dean of Arts and Sciences at Worcester Polytechnic Institute; and Ric Wiebl, currently director of…

  9. Communication and Mental Health: Psychiatric Forerunners.

    ERIC Educational Resources Information Center

    Brooks, Deems M.

    The connections between human communication and mental health were first noted 50 to 60 years ago by such early psychiatrists as Alfred Adler, Harry Stack Sullivan, and Karen Horney. They were concerned with understanding those communication processes and skills that make for effective, fully functioning human beings. Adler emphasized faulty…

  10. Collaborative Learning.

    ERIC Educational Resources Information Center

    Levy-Reiner, Sherry, Ed.

    1985-01-01

    Descriptions of 10 college programs involving collaborative learning are presented, along with Karen T. Romer's essay, "Collaboration: New Forms of Learning, New Ways of Thinking." The essay identifies various kinds of collaborative learning as well as the benefits of collaborative models. The following programs and schools are described: the…

  11. Secret Weapon Discovered! Scientists Say Parents Partnering with Teachers Can Change the Future of Education

    ERIC Educational Resources Information Center

    Furger, Roberta

    2006-01-01

    In "A New Wave of Evidence: The Impact of School, Family, and Community Connections on Student Achievement," published in 2002 by the Southwest Educational Development Laboratory, Anne T. Henderson and Karen Mapp reviewed years of research on parent involvement, and their conclusions are unequivocal. When parents are involved in school, students…

  12. Discipline-Based Art Education: Its Criticisms and Its Critics.

    ERIC Educational Resources Information Center

    Eisner, Elliot W.

    1988-01-01

    Discusses the criticisms of discipline-based art education published in the March 1988 issue of "Art Education." Responds to the arguments of Peter London, Helen Muth, Norma K. Pittard, and Karen Hamblen. States that art education would be better served if the energy devoted to criticism was directed toward constructive ends. (GEA)

  13. Using Data for School Improvement. Research Brief

    ERIC Educational Resources Information Center

    Education Partnerships, Inc., 2012

    2012-01-01

    How can principals and teachers use available data to plan school improvements? How can principals and teachers gather and analyze data that are useful for school reform? Karen Levesque and her colleagues sum up the problem of data use in schools this way. Most school districts and schools in this country are routinely involved in data collection.…

  14. Parity for Minorities in the Media. Hearing before the Subcommittee on Telecommunications, Consumer Protection, and Finance of the Committee on Energy and Commerce. House of Representatives, Ninety-Eighth Congress, First Session on H.R. 1155. A Bill to Amend the Communications Act of 1934 to Provide for Greater Participation of Minorities in Telecommunications.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    This transcript of a hearing on minority participation in telecommunications includes the text of the bill, H.R. 155; a summary of the bill from the Congressional Record; and testimony and statements from both individuals and representatives of several organizations. Testimony was presented by: (1) Karen English, Chicago, Illinois; (2) Janice…

  15. Out of Africa

    ERIC Educational Resources Information Center

    Wilbert, Nancy Corrigan

    2009-01-01

    Karen Blixen (Isak Dinesen), author of "Out of Africa," said, "God made the world round so people would never be able to see too far down the road." The author embraced this wonderful thought by venturing on a three-week journey to Kenya and Tanzania in search of grand adventure. In this article, the author shares her adventure with her students…

  16. Overcoming Language and Literacy Barriers: Using Student Response System Technology to Collect Quality Program Evaluation Data from Immigrant Participants

    ERIC Educational Resources Information Center

    Walker, Susan K.; Mao, Dung

    2016-01-01

    Student response system technology was employed for parenting education program evaluation data collection with Karen adults. The technology, with translation and use of an interpreter, provided an efficient and secure method that respected oral language and collective learning preferences and accommodated literacy needs. The method was popular…

  17. Sustaining Professional Learning Communities. The Soul of Educational Leadership Series

    ERIC Educational Resources Information Center

    Blankstein, Alan M., Ed.; Houston, Paul D., Ed.; Cole, Robert W., Ed.

    2007-01-01

    The third volume of "The Soul of Educational Leadership" series offers key concepts and strategies for sustaining the critically important work of professional learning communities. With contributions from Shirley Hord, Maurice Elias, Karen Seashore Louis, Andy Hargreaves, and other nationally known educators, this essential reading for all school…

  18. Building a Culinary Arts Academy

    ERIC Educational Resources Information Center

    Brown, Robert L.

    2005-01-01

    When Judy Karen Brown (the 2004 Alabama Family and Consumer Sciences Teacher of the Year) arrived at Bob Jones High School (BJHS) in Madison, Alabama, in the summer of 1999, she immediately identified a need to build both student and community interests in family and consumer sciences (FACS). She noticed the student and faculty interest in the…

  19. Schools and Staffing Survey: 1994. Papers Presented at the 1994 Meeting of the American Statistical Association. Working Paper Series.

    ERIC Educational Resources Information Center

    National Center for Education Statistics (ED), Washington, DC.

    The 14 papers presented in this proceedings include: (1) "Intersurvey Consistency in School Surveys" (Wray Smith, Al Holt, Steven Kaufman, and Fritz Scheuren); (2) "Estimation Issues Related to the Student Component of the SASS" (Karen Ellen King and Steven Kaufman); (3) "Properties of the Schools and Staffing Survey's Bootstrap Variance…

  20. Playing Their Way into Literacies: Reading, Writing, and Belonging in the Early Childhood Classroom. Language & Literacy Series

    ERIC Educational Resources Information Center

    Wohlwend, Karen E.

    2011-01-01

    Karen Wohlwend provides a new framework for rethinking the boundaries between literacy and play, so that play itself is viewed as a literacy practice along with reading, writing, and design. Through a variety of theoretical lenses, the author presents a portrait of literacy play that connects three play groups: the girls and, importantly, boys,…

  1. 75 FR 13318 - Virginia Electric and Power Company; Surry Power Station, Unit Nos. 1 and 2 (Surry 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... implementation date for Surry Unit 2. FOR FURTHER INFORMATION CONTACT: Karen Cotton, Office of Nuclear Reactor..., Division of Operating Licensing, Office of Nuclear Reactor Regulation. BILLING CODE 7590-01-P ... Register on March 3, 2010 (75 FR 9618), that cited the implementation date for compliance with Title 10...

  2. Forging a National Strategy for Success

    ERIC Educational Resources Information Center

    Reed, Jack

    2009-01-01

    At the National Staff Development Council's (NSDC's) 40th Annual Conference in December 2008, former NSDC Board President Karen Dyer and Executive Director Stephanie Hirsh presented the first Policy Maker of the Year Award to Senator Jack Reed (D-RI) in recognition of his dedicated work on behalf of legislation that promotes effective professional…

  3. 76 FR 58277 - Performance Review Board Members

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... M. Crosby, John Czajkowski, Cheryl R. Dammons, Michelle S. Davis, Nancy E. De Lew, Theodore M. Doolittle, Gregory J. Downing, Ivor D'Souza, Kana Enomoto, Michael E. Etzinger, Douglas B. Fridsma..., Karen V. Walker Bryce, Luis A. Wilmot, Holly J. Wong, Robert K. Yee, Cheryl L. Ziegler Ragland....

  4. Educational Reforms and Ethical Use of Research to Inform Readers

    ERIC Educational Resources Information Center

    Turgut, Guliz

    2013-01-01

    This article critique reflects on "Standards for a New Century: Educating U.S. Students to Compete in the Global Economy," which was published in 2009 in the "Carnegie Reporter", a publication of The Carnegie Corporation of New York. The article, written by Carnegie staff writer Karen Theroux, explained the need for Common Core…

  5. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (86th, Kansas City, Missouri, July 30-August 2, 2003). Communication Technology and Policy Division.

    ERIC Educational Resources Information Center

    2003

    The Communication Technology and Policy Division of the proceedings contains the following 15 papers: "Both Sides of the Digital Divide in Appalachia: Uses and Perceived Benefits of Internet Access" (Daniel Riffe); "Bridging Newsrooms and Classrooms: Preparing the Next Generation of Journalists for Converged Media" (Edgar Huang, Karen Davison,…

  6. The Effect of Adult Interactive Style on the Spontaneous Communication of Young Children with Autism at School

    ERIC Educational Resources Information Center

    Kossyvaki, Lila; Jones, Glenys; Guldberg, Karen

    2012-01-01

    Relatively little is known about the effect of adult interactive style on children's communication. The aim of this study, written by Lila Kossyvaki, Glenys Jones and Karen Guldberg, all from the University of Birmingham, was to explore the effects of adult interactive style on children's spontaneous communication. The study used an action…

  7. Transforming Education with Technology

    ERIC Educational Resources Information Center

    Scherer, Marge

    2011-01-01

    In this EL interview, Karen Cator, the director of the Office of Educational Technology at the U.S. Department of Education, talks about ways to realize the potential of technology to transform education. She discusses what students need: their own digital devices for classroom use, the ability to use the information they access, the skills to…

  8. Expanding Professional Development Opportunities to Enhance the Assessment Process

    ERIC Educational Resources Information Center

    Jones, Elizabeth A.

    2009-01-01

    The author has been working with colleagues Trudy Banta and Karen Black on a new Jossey-Bass book, "Designing Effective Assessment: Principles and Profiles of Good Practice," which focuses on assessment profiles from a variety of colleges and universities. These profiles also represent the spectrum of institutions from research universities to…

  9. Gifted Education Press Quarterly. Volume 10, 1996.

    ERIC Educational Resources Information Center

    Gifted Education Press Quarterly, 1996

    1996-01-01

    This set of four newsletters discusses current issues in gifted education. The first issue includes: "The Underserved Young Gifted Child: Status of Programs and Research" (Joan Smutny); "The Home Education Model: An Alternative Program for the Gifted" (Karen Kendig) and "Jonathan Swift (1667-1745): A Need for Gifted Readers" (Michael E. Walters).…

  10. Library Programs for Teens: Mystery Theater. VOYA Guides

    ERIC Educational Resources Information Center

    Siwak, Karen J.

    2010-01-01

    It's no mystery that fun and exciting programs bring teens into the library. Theater programs provide a venue for teens to express themselves creatively, encourage their participation in library programming, and offer them the opportunity for lively interaction with peers and adults. In "Library Programs for Teens: Mystery Theater," Karen Siwak…

  11. Campaigns to Overrule Campus Gun Bans Have Failed in Many States

    ERIC Educational Resources Information Center

    Lipka, Sara

    2008-01-01

    People can bring guns most places in Arizona, but the state's Board of Regents has long banned all weapons from public college campuses. Now some lawmakers are trying to change that. State Senator Karen S. Johnson, a Republican, proposed a bill in January that would trump the regents' ban, allowing anyone with a concealed-weapons permit to carry a…

  12. The Teacher-Student Writing Conference Reimaged: "Entangled Becoming-Writingconferencing"

    ERIC Educational Resources Information Center

    Phillips, Donna Kalmbach; Larson, Mindy Legard

    2013-01-01

    This analysis is experimental: we attempt to read data "with" the work of Karen Barad and in doing so "see" teacher-student writing conferences (a common pedagogy of US elementary school writing) as "intra-activity." Data were gathered during teacher-student writing conferences in a grade five US classroom over a…

  13. The Year in Review. Volume 3: 1993-1994. Reports of Research Conducted by Adult Education Practitioner-Researchers from Virginia.

    ERIC Educational Resources Information Center

    Virginia Adult Educators Research Network, Dayton.

    This document reports findings of eight Virginia adult educators who designed and conducted research projects within their programs. Abstracts and bibliographies appear first. "Why Tutors Do What They Do" (Karen Cook, Jean Dooley, Charles Fuller) examines responses of volunteer literacy tutors to questions about their expectations and training.…

  14. Tips & Techniques: Storytelling with Puppets and Props. [Videotape].

    ERIC Educational Resources Information Center

    2002

    On this 20-minute videotape, two accomplished storytellers share their expertise on using puppets and props to enhance the art of storytelling. Schroeder Cherry uses several types of puppets to tell his educational story about the Underground Railroad, while Karen Quinn-Wisniewski entertains her audience of young children with classic fables,…

  15. Grand Conversations across Texts

    ERIC Educational Resources Information Center

    Crafton, Linda K., Ed.; Johnson, Nancy J., Ed.

    2008-01-01

    This issue of "School Talk" brings together the ideas of purposefulness and intertextuality together in a teaching practice called intentional intertextual inquiry. "Making Inquiry Intentional and Intertextual" (Karen Smith, Sarah Diaz, and Silvia Edgerton) discusses the framework that combines inquiry-based learning and intertextuality within…

  16. 78 FR 53492 - California Disaster #CA-00208 Declaration of Economic Injury

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... Number 59002) Dated: August 19, 2013. Karen G. Mills, Administrator. [FR Doc. 2013-21154 Filed 08/28/2013... ADMINISTRATION California Disaster CA-00208 Declaration of Economic Injury AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Economic Injury Disaster Loan (EIDL)...

  17. 77 FR 3229 - Codex Alimentarius Commission: Codex Committee on Pesticide Residues (CCPR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    ... [Federal Register Volume 77, Number 14 (Monday, January 23, 2012)] [Notices] [Pages 3229-3230] [FR... Washington, DC, on January 17, 2012. Karen Stuck, U.S. Manager for Codex Alimentarius. [FR Doc. 2012-1160... Classification of Foods and Animal Feeds at Step 7: Fruit Commodity Groups (Excluding Edible Flowers and...

  18. Workplace Issues in Human Resources. Symposium 40. [AHRD Conference, 2001].

    ERIC Educational Resources Information Center

    2001

    This symposium on workplace issues in human resources consists of two presentations. "The Effect of Organizational Structure on Single-Source and Multiple-Source Performance Appraisal Processes: Implications for Human Resource Development (HRD)" (Karen K. Yarrish, Judith A. Kolb) investigates ratee acceptance of single- and multi-source…

  19. 78 FR 17205 - Notice of Availability of Service Contract Inventories

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... Notice of Availability of Service Contract Inventories AGENCY: Federal Maritime Commission. ACTION: Notice of availability of service contract inventories. FOR FURTHER INFORMATION CONTACT: Karen V. Gregory... notice to advise the public of the availability of the FY 2011 Service Contract Inventory Analysis,...

  20. Proceedings of the Annual Midwest Research-to-Practice Conference in Adult, Continuing and Community Education (16th, East Lansing, Michigan, October 15-17, 1997).

    ERIC Educational Resources Information Center

    Levine, S. Joseph, Ed.

    This proceedings contains 29 presentations: "Meaning of Participating in Technology Training" (Cynthia S. Blodgett-McDeavitt); "Applying Actor Network Theory to Curricular Change in Medical Schools" (Karen V. Busch); "Politics of Humanism" (Mary Katherine Cooper); "Reasons for the Nonparticipation of Adults in Rural Literacy Programs in Western…

  1. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (78th, Washington, DC, August 9-12, 1995). Qualitative Studies Division.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The Qualitative Studies section of the proceedings contains the following 14 papers: "'Virtual Anonymity': Online Accountability in Political Bulletin Boards and the Makings of the Virtuous Virtual Journalist" (Jane B. Singer); "The Case of the Mysterious Ritual: 'Murder, She Wrote' and 'Perry Mason'" (Karen E. Riggs); "Political Issues in the…

  2. The Social and Emotional Development of Gifted Children: What Do We Know?

    ERIC Educational Resources Information Center

    Neihart, Maureen, Ed.; Reis, Sally M., Ed.; Robinson, Nancy M., Ed.; Moon, Sidney M., Ed.

    This text on the social and emotional development of gifted children includes the following 24 papers: (1) "Effects of Acceleration on Gifted Learners" (Karen Rogers); (2) "Peer Pressures and Social Acceptance of Gifted Students" (Sylvia Rimm); (3) "Social and Emotional Issues for Exceptional Intellectually Gifted Students" (Miraca Gross); (4)…

  3. Vocational Education Today: Topical Issues.

    ERIC Educational Resources Information Center

    Kenway, Jane, Ed.; Tregenza, Karen, Ed.; Watkins, Peter, Ed.

    This book contains 13 papers examining topical issues in vocational education and training (VET) in Victoria, Australia. The following papers are included: "Vocational Education and Schooling: The Changing Scene" (Jane Kenway, Sue Willis, Peter Watkins, Karen Tregenza); "The Enterprise Approach" (James Mulraney); "VET Programs at James Harrison…

  4. On Physical Attractiveness Stereotyping in Taiwan: A Revised Sociocultural Perspective.

    ERIC Educational Resources Information Center

    Chen, Nicole Y.; Shaffer, David R.; Wu, Chenghuan

    1997-01-01

    Questions the current thesis that people from "collectivist" cultures are less likely to make character inferences based on physical attractiveness. Presents the results of a study that revealed Taiwanese undergraduates assigning positive character attributes to people based on their physical attractiveness. Discusses related literature (Karen K.…

  5. New Perspectives in Human Resource Development.

    ERIC Educational Resources Information Center

    1999

    These three papers are from a symposium on new perspectives in human resource development (HRD). "Developing an Instrument to Measure the Use of Play-Based Training Methods in Healthcare Education" (Rebecca J. Adams, Karen E. Watkins, Tom Valentine) reports preliminary findings from a pilot study that tested data collection procedures and the…

  6. Time and Learning: Scheduling for Success. Hot Topics Series.

    ERIC Educational Resources Information Center

    Kennedy, Robert L., Ed.; Witcher, Ann E., Ed.

    This book provides information for educators considering ways to make the best use of time available for learning. Twenty-one articles are divided into 5 chapters. Chapter 1: "How Can We Make the Most of the School Day?" includes an overview and 6 articles: (1) "Block Scheduling" (Karen Irmsher); (2)"The Hybrid Schedule: Scheduling to the…

  7. Coalition for Education in the Outdoors Research Symposium Proceedings (4th, Bradford Woods, Indiana, January 9-11, 1998).

    ERIC Educational Resources Information Center

    Fox, Karen M., Ed.; Foti, Pamela E., Ed.; McAvoy, Leo H., Ed.; Young, Anderson B., Ed.; Ryan, Sean, Ed.; Johnson, Rebecca, Ed.; Bialeschki, M. Deborah, Ed.

    This proceedings contains 13 papers from the 1998 Research Symposium of the Coalition for Education in the Outdoors. Following a preface "Building the Research Foundations of Outdoor Education" (Karen M. Fox, Leo H. McAvoy, Anderson B. Young), the entries are: (1) "An Integrative Review of the Literature on Women in the Outdoors" (Karla A.…

  8. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  9. Superintendents' Husbands: Encourage, Support and Bide Their Free Time

    ERIC Educational Resources Information Center

    Goldman, Jay P.

    2012-01-01

    When Karen Rue was on the verge of accepting her first superintendent appointment 11 years ago, her husband Gary anticipated he might be asked to play the role of "first spouse," serving as informal ambassador for the school district. He was correct. Gary Rue, a retired physical education teacher, has willingly served as his wife's fill-in at…

  10. Why Do Bees Sting? Reflecting on Talk in Science Lessons

    ERIC Educational Resources Information Center

    Boctor, Sonia; Rowell, Patricia M.

    2004-01-01

    Learning science in a meaningful way involves more than doing a series of activities directed towards anticipated outcomes. Learning science entails teacher and children talking together as "co-constructors" of knowledge (Barnes, 1976). Karen Gallas (1995) has described her long-term observations of the kinds of talk which contribute to a…

  11. Information Literacy Assessment

    ERIC Educational Resources Information Center

    Warmkessel, Marjorie M.

    2007-01-01

    This article presents an annotated list of seven recent articles on the topic of information literacy assessment. They include: (1) "The Three Arenas of Information Literacy Assessment" (Bonnie Gratch Lindauer); (2) "Testing the Effectiveness of Interactive Multimedia for Library-User Education" (Karen Markey et al.); (3) "Assessing Auburn…

  12. Strong Female Characters in Recent Children's Literature.

    ERIC Educational Resources Information Center

    Heine, Pat; Inkster, Christine; Kazemek, Frank; Williams, Sandra; Raschke, Sylvia; Stevens, Della

    1999-01-01

    Shares the authors' criteria for evaluating female characters as positive role models in children's literature. Explores the criteria by examining "The Ballad of Lucy Wipple" (Karen Cushman). Discusses other recently published picture books and novels which feature strong females in history, in contemporary times, and in fantasy. (SR)

  13. Distance Education in Southern Africa Conference, 1987. Papers 5: Administration and Student Support in Distance Education.

    ERIC Educational Resources Information Center

    Adey, David, Comp.; And Others

    Seventeen papers from the University of South Africa's Conference on Distance Education are presented. They include: "Establishing a Formal Student Support System--Time Is of the Essence" (Karen Hinrichs); "A Student Services Unit in a Distance Education Institution" (Hendrik Gous); "Distance Education and the Community: New Partnerships and…

  14. Managing cytotoxic chemotherapy extravasation: use of saline washout.

    PubMed

    Harrold, Karen

    Florence Nightingale Foundation scholar Karen Harrold received funding to support her PhD exploring the patient experience of saline washout as a management strategy for chemotherapy extravasation. She discusses the focus of her thesis, the completion of phase one and looks ahead to phase two. PMID:25904536

  15. Autism and Multidisciplinary Teamwork through the SCERTS Model

    ERIC Educational Resources Information Center

    Molteni, Paola; Guldberg, Karen; Logan, Nick

    2013-01-01

    This research investigates multidisciplinary teamwork in an English special school located in the West Midlands region of the UK. The research was carried out by Paola Molteni, a PhD student at Università Cattolica del Sacro Cuore, Milan, Karen Guldberg of the Autism Centre for Education and Research Director at the University of Birmingham School…

  16. Academic Freedom as a Rhetorical Construction: A Response to Powers and Chaput

    ERIC Educational Resources Information Center

    Abraham, Matthew

    2008-01-01

    M. Karen Powers and Catherine Chaput's ""Anti-American Studies" in the Deep South: Dissenting Rhetorics, the Practice of Democracy, and Academic Freedom in Wartime Universities" begins a much needed discussion about the current and ongoing assaults against academic freedom in American universities, which have not received adequate treatment within…

  17. 78 FR 60285 - Final Notice To Announce the Implementation of Required Electronic Submission of State or Tribal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-01

    ... responses to comments received under the initial notice published in the Federal Register (78 FR 38989-38891... for Children and Families, Division of Grants Policy, 370 L'Enfant Promenade SW., Aerospace Building, 6th Floor East, Washington, DC 20447. Email address: karen.shields@acf.hhs.gov ....

  18. "A Clash of Two Worlds"; Disjuncture between the Norms and Values Held by Educational Practitioners and Parents of Children with Behavioural, Emotional and Social Difficulties

    ERIC Educational Resources Information Center

    Broomhead, Karen

    2014-01-01

    This article, by Karen Broomhead of Liverpool John Moores University, discusses an exploration of the clashing norms, values and expectations of parenting behaviours between parents of children with behavioural, emotional and social difficulties (BESD) and practitioners. Semi-structured interviews with 15 education professionals, employed in both…

  19. 77 FR 12304 - Notice of Agreements Filed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    .... Filing Party: Wade S. Hooker, Esq.; 211 Central Park W, New York, NY 10024. Synopsis: The adds Peter... Exchange Agreement Asia--U.S. East Coast. Parties: China Shipping Container Lines Co., Ltd., China Shipping... Gulf Coasts and Asia. By Order of the Federal Maritime Commission. Dated: February 24, 2012. Karen...

  20. Meeting the Home Language Mandate: Practical Strategies for All Classrooms

    ERIC Educational Resources Information Center

    Nemeth, Karen

    2009-01-01

    Experts throughout the United States tell us that teachers must support the home language development of all young children. Karen Nemeth emphasizes the important role early childhood educators play in ensuring that young dual language learners retain skills in their home language while building new English language skills. She invites educators…