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Depósitos de fluxo piroclástico primários: caracterização e estudo de um caso no vulcanismo ácido neoproterozóico do escudo sul-rio-grandense

Sommer, Carlos Augusto; Lima, Evandro Fernandes de; Nardi, Lauro Valentim Stoll; Liz, Joaquim Daniel de; Pierosan, Ronaldo
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
Relevância na Pesquisa
26.86%
Volcanic deposits can be included in two main groups: coherent and volcaniclastic. The former results from volcanic and sub-volcanic (syn-volcanic intrusions) effusive events, excluding autoclastic portions, and the second group, which is related to deposits constituted by volcanic fragments, encompassing primary deposits (pyroclastic) generated from fragment dispersion through gases and hot vapour, syn-eruptive resedimented deposits, besides volcanogenic sedimentary deposits. Clast transport processes are separated in three broad categories: mass-flow, traction and suspension. Basic concepts that are used in the study of volcanic rocks, classification and characterization of the main subaerial pyroclastic deposits are discussed in this paper, considering lithological and genetic aspects. Lithological aspects are mainly related to composition, components and grain-size of the deposits, while genetic aspects and interpretations are based on clast-forming and depositional processes, allowing understanding about eruption and emplacement conditions. Emphasis is given to pumiceous pyroclastic flow deposits, describing their main textural features and the post-depositional modifications associated to them. The discussed concepts are applied in the reconstruction of the Neoproterozoic pyroclastic flow deposits of two plateaus in the Sul-rio-grandense Shield...

Caracterização espectro-mineralogica e aspectos sobre a genese de materias-primas ceramicas classicas do Brasil : estudos de caso em depositos de pirofillita, talco e caulinita; Spectral-mineralogical characterization and genetic aspects of classic Brazilian ceramic materials : case studies in pyrophillite, talc and kaolinite deposits

Juliano Alves de Senna
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/08/2008 PT
Relevância na Pesquisa
26.82%
Matérias primas cerâmicas (MP.C) naturais são materiais geológicos que exercem papel fundamental na economia de países mais desenvolvidos. Entretanto, no Brasil há uma tendência histórica em preterir investimentos na prospecção e explotação destes bens não metálicos em relação aos metálicos. Em função disso, os métodos de lavra até hoje utilizados são empíricos e o controle de qualidade precário, salvo alguns . poucos depósitos administrados por grandes grupos mineradores. Neste sentido, há uma clara lacuna tecnológica a ser preenchida neste setor no Brasil. A Espectroscopia de Reflectância (ER), baseada na faixa do visível e infravermelho de ondas curtas (0.4-2.5um), é uma ferramenta fundamental do sensoriamento remoto e eficaz na detecção de óxidos e hidróxidos de ferro e alumínio, carbonatos e filossilicatos. Seu uso potencial para caracterização espectro-mineral de MPCs é significativo, visto que não requer nenhuma preparação, é uma técnica rápida e de simples operacionalidade, e as análises podem ser feitas diretamente in situo Considerando as complexidades envolvidas nesta caracterização, os objetivos desta pesquisa foram: (i) avaliar a eficácia da ER em separar as faciologias dos minérios...

Depósitos auríferos associados ao magmatismo félsico da Província de Alta Floresta (MT), Cráton Amazônico : litogeoquímica, idade das mineralizações e fonte dos fluidos; Intrusion-hosted gold deposits related to the felsic magmatism of the Alta Floresta Gold Province (MT), Amazon Craton : lithogeochemistry, mineralization ages and source of fluids

Rafael Rodrigues de Assis
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/03/2015 PT
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26.92%
MINERALIZAÇÕES E FONTE DOS FLUIDOS. A Província Aurífera de Alta Floresta, porção centro-sul do Craton Amazônico, localiza-se entre os limites das províncias geocronológicas Ventuari - Tapajós (1,95-1,8 Ga) e Rio Negro - Juruena (1,8-1,55 Ga), ou entre as províncias tectônicas Tapajós - Parima (2,03-1,88 Ga) e Rondônia - Juruena (1,82-1,54 Ga), a depender do modelo adotado para o cráton. Ela é essencialmente constituída por sequências plutôno-vulcânicas derivadas de diversos arcos vulcânicos amalgamados no decorrer do Paleoproterozóico. No segmento leste da província, na região que compreende as cidades de Peixoto de Azevedo - Matupá - Guarantã do Norte - Novo Mundo (MT), rochas plutônicas e vulcânicas de composição granítica hospedam mais de uma centena de depósitos auríferos concentrados ao longo do Cinturão Peru ¿ União do Norte, de direção NW-SE. Com base na paragênese e estilo do minério, essas mineralizações podem ser agrupadas em três tipologias principais: (1) Au ± Cu disseminados em sistemas graníticos e dominantemente representados por pirita e concentrações variáveis de calcopirita e hematita; (2) Sistemas filonares de Au ± Cu essencialmente constituídos por pirita com calcopirita subordinada; e (3) Au + metais de base confinados a veios e vênulas que truncam sequências vulcano-sedimentares sin- a pós-tectônicas. Neste contexto...

Sustained Expression of Osteopontin Is Closely Associated with Calcium Deposits in the Rat Hippocampus After Transient Forebrain Ischemia

Park, Jang-Mi; Shin, Yoo-Jin; Kim, Hong Lim; Cho, Jeong Min; Lee, Mun-Yong
Fonte: SAGE Publications Publicador: SAGE Publications
Tipo: Artigo de Revista Científica
Publicado em /07/2012 EN
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26.82%
The present study was designed to evaluate the extent and topography of osteopontin (OPN) protein expression in the rat hippocampus 4 to 12 weeks following transient forebrain ischemia, and to compare OPN expression patterns with those of calcium deposits and astroglial and microglial reactions. Two patterns of OPN staining were recognized by light microscopy: 1) a diffuse pattern of tiny granular deposits throughout the CA1 region at 4 weeks after ischemia and 2) non-diffuse ovoid to round deposits, which formed conglomerates in the CA1 pyramidal cell layer over the chronic interval of 8 to 12 weeks. Immunogold-silver electron microscopy and electron probe microanalysis demonstrated that OPN deposits were indeed diverse types of calcium deposits, which were clearly delineated by profuse silver grains indicative of OPN expression. Intracellular OPN deposits were frequently observed within reactive astrocytes and neurons 4 weeks after ischemia but rarely at later times. By contrast, extracellular OPN deposits progressively increased in size and appeared to be gradually phagocytized by microglia or brain macrophages and some astrocytes over 8 to 12 weeks. These data indicate an interaction between OPN and calcium in the hippocampus in the chronic period after ischemia...

Clinicopathological Characteristics and Outcomes of Chinese Patients with Scanty Immune Deposits Lupus Nephritis: A Large Cohort Study from a Single Center

Li, Qiuyu; Song, Di; Wang, Fengmei; Tan, Ying; Yu, Feng; Zhao, Minghui
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 04/02/2014 EN
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Objective. To assess clinicopathological characteristics of lupus nephritis patients with scanty immune deposits. Methods. The data of patients with scanty immune deposits lupus nephritis were retrospectively analyzed. Plasma ANCA and complement components were detected. Results. Among 316 cases with renal biopsy-proven lupus nephritis, 40 cases were diagnosed as scanty immune deposits. There were significantly higher value of serum creatinine (P = 0.002) and lower hemoglobin level (P = 0.009) and higher score of cellular crescents (P = 0.015) in scanty immune deposits group compared with immune complex deposits group. The frequency of positive plasma ANCA was significantly higher in scanty immune deposits group than that in immune complex deposits group (52.5% versus 10.1%, P < 0.001). As for comparisons of plasma complement components, there were significantly higher levels of C1q (P = 0.005) and Bb (P = 0.02) and lower level of factor H (P = 0.003) in scanty immune deposits group. The ratio of treatment failure was significantly higher in scanty immune deposits group than that in immune deposits group (42.5% versus 19.20%, P = 0.001). The renal outcomes were similar between the two groups. Conclusions. Patients with scanty immune deposits lupus nephritis had more severe kidney damage. ANCA and activation of complement alternative pathway might be involved in the pathogenesis of the disease.

Should Mesenteric Tumor Deposits Be Included in Staging of Well-differentiated Small Intestine Neuroendocrine Tumors?

Gonzalez, Raul S.; Liu, Eric H.; Alvarez, JoAnn Rudd; Ayers, Gregory D.; Washington, M. Kay; Shi, Chanjuan
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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26.84%
Well-differentiated small intestine neuroendocrine tumors can give rise to mesenteric tumor deposits, which are not included in the current American Joint Committee on Cancer staging system for small intestine neuroendocrine tumors, and their impact on patient prognosis is unknown. Seventy-two small intestine neuroendocrine tumors resections were identified in our files with slides, reports, and follow-up data available. Cases were assessed for T-category and for the presence of mesenteric tumor deposits, lymph node metastases, lymphovascular invasion, and liver metastases. Mesenteric tumor deposits were defined as discrete mesenteric tumor nodules > 1mm with an irregular growth profile. Similar lesions clearly resulting from extranodal extension or direct contiguous spread by the primary lesion were excluded. Forty-three of the 72 cases had mesenteric tumor deposits (60%). The deposits were significantly associated with lymphovascular invasion (p=0.001), pT3 or pT4 disease (p=0.001), nodal metastases (p=0.040), and liver metastases (p<0.001) at time of surgery. In addition, 4 of 6 cases with tumor deposits and no nodal disease had liver disease. Tumor deposits were associated with an increased incidence of disease progression and death due to the disease (p = 0.001). Finally...

Tumor deposits in rectal adenocarcinoma after neoadjuvant chemoradiation are associated with poor prognosis

Gopal, Purva; Lu, Pengcheng; Ayers, Gregory D; Herline, Alan J; Washington, Mary K
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Although tumor deposits have been associated with poor prognosis in colorectal carcinoma, the prevalence and clinical significance of tumor deposits in rectal adenocarcinoma following neoadjuvant chemoradiation are relatively unexplored. The aims of this study are to assess the clinical significance of tumor deposits in rectal adenocarcinoma patients, including those receiving neoadjuvant therapy. Pathology slides and medical records from 205 consecutive patients who underwent resection for rectal adenocarcinoma between 1990 and 2010 at a single tertiary care center were reviewed. Patients with tumor deposits had higher tumor grade (P=0.006) and worse tumor stage (P<0.001) at presentation than patients without tumor deposits. Among 110 patients who underwent neoadjuvant chemoradiation, tumor deposits were associated with higher rates of lymph node involvement (P=0.035) and distant metastases (P=0.006), and decreased survival (P=0.027). These patients had a trend toward lower treatment response scores (P=0.285) and higher local recurrence (P=0.092). Of 52 patients with tumor deposits, those who underwent neoadjuvant chemoradiation had significantly worse pretreatment stage by endoscopic ultrasound (P=0.001) but interestingly had significantly lower rates of lymphovascular invasion on resection (P<0.001) compared with those who had not received neoadjuvant chemoradiation. Despite treatment with neoadjuvant chemoradiation...

Payment Systems, Inside Money and Financial Intermediation

Merrouche, Ouarda; Nier, Erlend
Fonte: Banco Mundial Publicador: Banco Mundial
Relevância na Pesquisa
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This paper assesses the impact of introducing an efficient payment system on the amount of credit provided by the banking system. Two channels are investigated. First, innovations in wholesale payments technology enhance the security and speed of deposits as a payment medium for customers and therefore affect the split between holdings of cash and the holdings of deposits that can be intermediated by the banking system. Second, innovations in wholesale payments technology help establish well-functioning interbank markets for end-of-day funds, which reduces the need for banks to hold excess reserves. The authors examine these links empirically using payment system reforms in Eastern European countries as a laboratory. The analysis finds evidence that reforms led to a shift away from cash in favor of demand deposits and that this in turn enabled a prolonged credit expansion in the sample countries. By contrast, while payment system innovations also led to a reduction in excess reserves in some countries...

Inside the Crisis : An Empirical Analysis of Banking Systems in Distress

Demirguc-Kunt, Asli; Detragiache, Enrica; Gupta, Poonam
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
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26.86%
Much of the substantial literature on banking crises, focuses on early warning indicators. The authors look at what happens to the economy, and the banking sector after a banking crisis breaks out. Much of the theory of banking crises assigns a central role to depositor runs, with vulnerability to runs viewed as a basic characteristic of banks as financial intermediaries. But banking systems can be financially distressed, even when depositors do not withdraw their deposits, if other bank creditors rush for the exit, or if banks become insolvent. Are contemporary banking crises characterized by large declines in deposits? The authors find that contemporary banking crises are not accompanied by declines in aggregate bank deposits, and credit does not fall relative to output, but the growth of both deposits, and credit does slow down substantially. Output recovery begins the second year after the crisis, and is not led by a resumption of credit growth. Instead, banks (including the stronger banks) reallocate their asset portfolio away from loans. This suggests that protecting deposits during a banking crisis...

Hochkantschille: Bivalven-Akkumulationen im Wattenmeer. Beschreibung, Taphonomie, Genese sowie zeitliche und räumliche Entwicklung; Vertical packed shells: Bivalves-accumulations in the Wadden Sea. Description, taphonomic, genesis as soon as temporal and spatial development

Federolf, Christian M. J.
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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In dieser Arbeit werden rezente Mya arenaria dominierende Schill-Vorkommen innerhalb des Gezeitenbereiches zwischen Jadebucht und Außenelbe untersucht. Ziel ist es Informationen über dessen Aufbau sowie ihrer Genese zu erhalten. Besonders betrachtet werden dabei die bislang selten beschriebenen Hochkantstrukturen. Im 1. Kapitel wird ein Überblick in die Thematik der Schalen-Akkumulationen, das Untersuchungsgebiet sowie der Muschelart M. arenaria gegeben. Das 2. Kapitel beschäftigt sich mit der Beschreibung von drei Schill-Vorkommen. Es folgen detaillierte Aufnahmen der Oberflächenstrukturen sowie mehrerer Reliefgussprofile. Die Ergebnisse zeigen, dass die Akkumulationen hauptsächlich durch laterale Priel-Wanderungen verursacht werden. Aufgrund von Erosionsprozessen werden ehemalige M. arenaria Siedlungshorizonte freigelegt. Durch biostratinomische Prozesse die durch hydrodynamische Ereignisse gesteuert werden entstehen wiederkehrende und charakteristische Lagerungs- und Einregelungsmuster. Aufgrund dessen erfolgt eine allgemeine Einteilung in sieben unterschiedliche Zonenbereiche. Es kann festgestellt werden, dass die ansteigende Morphologie der Schill-Vorkommen eine Veränderung der hydrodynamischen Wirkungsgrenze des Wassers während der Tidenzyklen verursacht und für die unterschiedlichen Lagerungszustände verantwortlich ist. Im 3. Kapitel wird das Schalenmaterial zweier Transekte einer semi-quantitativen Analyse unterzogen bei der fünf Beanspruchungsmerkmale erfasst wurden. Neben bivariaten Korrelationsanalysen und Größenhäufigkeitsverteilungen...

Semi-automatic identification of neogenic deposits by using high resolution digital surface models in Southeastern Brazil

Lima Silva, Sonia Maria
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertação
EN
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26.82%
The Cenozoic deposits occupy large areas of the Brazilian territory with parts subject to intense human occupation. Nevertheless they are still little known and researched. One of the most important Cenozoic sedimentary units in Brazil corresponds to Barreiras Formation (Neogene), which is located along almost all of the Brazilian coast. Geomorphologically the deposits of the Barreiras Formation are associated with a relief of tabular forms, dissected into deep valleys with steep slopes. This research aims to develop a semi-automatic method of detailed scale mapping Barreiras Formation deposits by employing Digital Surface Models (DSMs) obtained from high resolution satellite images. The justification of this research is based on both: the lack of cartographic databases on the scale of 1:25.000, as well as the lack of maps representing these deposits in more detailed scale necessary for their proper description and interpretation. The selected area is located in the northern region of the State of Rio de Janeiro, between the city of Campos dos Goytacazes and the border to the State of Espírito Santo. In this area the most significant occurrence of Barreiras Formation deposits in the State of Rio de Janeiro is found. The main goal to be achieved in this research is the identification of such deposits by evaluating their geomorphological characteristics which are modeled by specific variables that represent these aspects. The study on the potential of the use of stereoscopic capabilities of high resolution images coming from ALOS/PRISM sensor...

Updated estimates of EU eligible and covered deposits

CANNAS GIUSEPPINA; CARIBONI Jessica; KAZEMI VEISARI LALEH; PAGANO Andrea
Fonte: Publications Office of the European Union Publicador: Publications Office of the European Union
Tipo: EUR - Scientific and Technical Research Reports Formato: Online
ENG
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This report presents JRC data and quantitative analyses estimating the amounts of EU total, eligible and covered deposits. Three sources of data have been used to build the dataset: ­- a survey distributed by JRC in summer 2013 to all mandatory EU deposit guarantee schemes ; - ECB public statistics on aggregated balance sheets of MFIs and ­- Bankscope data to cross check and combine data from the above sources. Considering all EU MS total deposits amount to roughly 14,500 EUR billion in 2011-2012. Deposits eligible for protection from deposits guarantee schemes represent on average 74% of the total deposits. Deposits below the 100,000 EUR coverage level, so called covered deposits, are roughly 66% of the eligible deposits. Our estimates imply that the aggregated amount of EU covered deposits is about 5,200 EUR billion.; JRC.G.1-Scientific Support to Financial Analysis

Genesis of intrusive-related hydrothermal gold deposits

Matthai, Stephan K.
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD)
EN_AU
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26.89%
The nature of gold transport and deposition in deep, intrusive-related hydrothermal systems has been the topic of this PhD-research. Specifically, the role of I-type granites in the formation of gold deposits that occur in contact metamorphic aureoles has been addressed by an integrated field study of gold deposits in the aureole of the Cullen Batholith in the Proterozoic Pine Creek Inlier, northern Australia. This investigation shows that gold was deposited in quartz vein which formed near the thermal peak of contact metamorphism at 550 ::; T ::; 620°C at a pressure around 200 MPa. Gold is localized within quartz veins that occupy fracture arrays in a variety of structural types of major antiforms. The gold veins formed in two distinct structural settings. In the first, the veins indicate fluid flow focusing while the host structure was actively deforming. In the second, predominantly beddingconformable vein systems and randomly oriented stockworks indicate the focusing of fluids into anticlines in the absence of deformation. On a regional scale, gold mineralization occurs where the vein systems intersect carbonaceous units in the metapelitic host-rock sequence or where veins formed near carbonaceous units (::;100 m to contacts). Although abundant...

Banking in Developing Countries in the 1990s

Hanson, James A.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH
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26.89%
During the 1990s commercial bank deposits and capital rose relative to GDP in the major developing countries. This rise largely reflected the dramatic fall in inflation of the 1990s and financial liberalization. But much of this growth in banks' loanable funds was absorbed by increased net holdings of central bank debt and of government debt. Much of the rise in government debt reflected post-crisis restructurings, notably in Brazil, Indonesia, and Mexico, but rising deficits also played a role. Bank intermediation between depositors and private sector borrowers remained limited in many countries despite financial liberalization. The post-crisis restructurings raise two important issues: the poor performance of loans that was revealed by the crises and the future crowding-out that will result from the spreading-out of the cost of the crisis over time and the inability to retire the restructuring-related debt. The absorption of deposits in nonprivate sector credit, the growth of offshore finance of the private sector...

Detection of immune deposits in skin lesions of patients with Wegener's granulomatosis

Brons, R; de Jong, M C J M; de Boer, N K; Stegeman, C; Kallenberg, C; Tervaert, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/2001 EN
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26.84%
BACKGROUND—Wegener's granulomatosis (WG) is considered a pauci-immune systemic vasculitis based on the absence of immune deposits in renal biopsies of patients with active disease. In animal models of antineutrophil cytoplasmic antibody (ANCA) associated glomerulonephritis, immune deposits along the glomerular capillary wall are present at early stages of lesion development. These deposits are degraded rapidly, resulting in "pauci-immune" lesions.
OBJECTIVE—To test the hypothesis that immune deposits can also be detected in early lesions of patients with WG, thereby initiating an inflammatory reaction that, in time, is augmented in the presence of ANCA, resulting in pauci-immune lesions later on.
METHODS—The presence of immune deposits in skin biopsies taken within 48 hours of lesion development was investigated. Direct immunofluorescence was used to examine 32 skin biopsies for the presence of immune deposits (IgG, IgA, IgM, C3c). When possible, a comparison was made between the immunofluorescence findings in renal and skin biopsies taken at the same time.
RESULTS—Four of 11 biopsies taken at initial presentation and four of 21 biopsies taken at the onset of a relapse of WG showed IgG and/or IgA containing immune deposits in the subepidermal blood vessels. All nine renal biopsies showed pauci-immune glomerulonephritis...

Changes in the architecture of fluvial deposits in the Paganzo Basin (Upper Paleozoic of San Juan province): an example of sea level and climatic controls on the development of coastal fluvial environments

Tedesco, A.; Ciccioli, P.; Suriano, J.; Limarino, C.O.
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2010 ENG
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26.87%
Paganzo Group exposures (Tupe Formation) in the Huaco area provide an excellent opportunity for assessing the role of sea level and climatic changes on the morphology and nature of coastal fluvial systems deposited in areas of limited tectonic activity. The paleogeographic position of Huaco, close to a coastal region within the Paganzo Basin, allows identification of the effects of sea level change on fluvial architecture. Despite the fact that the Huaco area was dominated by coastal fluvial systems, three marine incursions flooded this part of the basin during the Namurian, Early Pennsylvanian and Late Pennsylvanian respectively. During deposition of the Paganzo Group, climatic conditions evolved from glacial (Namurian) to hot and dry (Late Cisuralian). Five types of fluvial deposits were recognized on the basis of architectural element analysis, lithofacies distribution and type of fluvial bounding surfaces present. Fluvial system 1 (FS1) constitutes the lower part of the Tupe Formation and consists of stacked multi-storey channel-fill complexes formed on large braided alluvial plains dominated by channel-avulsion processes. FS2 consists of multi-storey channels alternating with floodplain deposits including coal beds and organic-rich mudstones. This fluvial system is interpreted as the deposit of an anastomosed network of sandy channels. FS3 occurs between the Early Pennsylvanian and Late Pennsylvanian marine transgressions and consists of sandstones and some conglomerates that form stacked channel complexes. Sporadically...

Stratigraphy of Aeolis Dorsa, Mars: Stratigraphic context of the great river deposits

Kite, Edwin S.; Howard, Alan D.; Lucas, Antoine S.; Armstrong, John C.; Aharonson, Oded; Lamb, Michael P.
Fonte: Elsevier Publicador: Elsevier
Tipo: Article; PeerReviewed Formato: application/msword
Publicado em /06/2015
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26.96%
Unraveling the stratigraphic record is the key to understanding ancient climate and past climate changes on Mars (Grotzinger, J. et al. [2011]. Astrobiology 11, 77–87). Stratigraphic records of river deposits hold particular promise because rain or snowmelt must exceed infiltration plus evaporation to allow sediment transport by rivers. Therefore, river deposits when placed in stratigraphic order could constrain the number, magnitudes, and durations of the wettest (and presumably most habitable) climates in Mars history. We use crosscutting relationships to establish the stratigraphic context of river and alluvial-fan deposits in the Aeolis Dorsa sedimentary basin, 10°E of Gale crater. At Aeolis Dorsa, wind erosion has exhumed a stratigraphic section of sedimentary rocks consisting of at least four unconformity-bounded rock packages, recording three or more distinct episodes of surface runoff. Early deposits (>700 m thick) are embayed by river deposits (>400 m thick), which are in turn unconformably draped by fan-shaped deposits (<100 m thick) which we interpret as alluvial fans. Yardang-forming layered deposits (>900 m thick) unconformably drape all previous deposits. River deposits embay a dissected landscape formed of sedimentary rock. The river deposits are eroding out of at least two distinguishable units. There is evidence for pulses of erosion during the interval of river deposition. The total interval spanned by river deposits is >(1 × 10^6–2 × 10^7) yr...

Hydrogeology of a Rapid Infiltration Basin System (RIBS) at Cape Henlopen State Park, Delaware

Andres, A.S.; Walther, E.F.; Türkmen, M.; He, C.
Fonte: Newark, DE: Delaware Geological Survey, University of Delaware Publicador: Newark, DE: Delaware Geological Survey, University of Delaware
Tipo: Relatório
EN_US
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The hydrogeologic framework of Cape Henlopen State Park (CHSP), Delaware was characterized to document the hydrologic effects of treated wastewater disposal on a rapid infiltration basin system (RIBS). Characterization efforts included installation of test borings and monitoring wells; collection of core samples, geophysical logs, hydraulic test data, groundwater levels and temperatures; testing of grain size distribution; and interpretation of stratigraphic lithofacies, hydraulic test data, groundwater levels, and temperature data. This work was part of a larger effort to assess the potential benefits and risks of using RIBS in Delaware. The infiltration basins at CHSP are constructed on the Great Dune, an aeolian dune feature composed of relatively uniform, medium-grained quartz sand. The age of the dune, determined by carbon-14 dating of woody material in swamp deposits under the dune, is less than 800 years. Underlying the dune deposits are relatively heterogeneous, areally continuous, coarse-grained spit deposits of the proto-Cape Henlopen spit with interbedded and relatively fine-grained, discontinuous swamp and marsh deposits, and beneath, relatively fine-grained, continuous, near-shore marine deposits. The dune deposits can be 45 ft thick under the crest of the dune and nonexistent at the surface. Spit deposits range from 5 to 15 ft thick. Test drilling determined that the near-shore marine deposits are at least 10 ft thick in the vicinity of the infiltration basins. The complete thickness of these deposits was not determined in this study. Hydraulic testing and grain-size data indicate that the dune and spit deposits are relatively permeable...

The Pliocene And Quaternary Deposits Of Delaware: Palynology, Ages, And Paleoenvironments

Groot, J.J.; Jordan, R.R.
Fonte: Newark, DE: Delaware Geological Survey, University of Delaware Publicador: Newark, DE: Delaware Geological Survey, University of Delaware
Tipo: Relatório
EN_US
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36.47%
The surficial Pliocene and Quaternary sedimentary deposits of the Atlantic Coastal Plain of Delaware comprise several formal and informal stratigraphic units. Their ages and the paleoenvironments they represent are interpreted on the basis of palynological and lithologic data and, to a lesser degree, on geomorphology.

On the significance of magnetic anomalies from the Baja California Peninsula: its relationship with IOCG deposits and the deep crustal magnetic layer

García-Abdeslem,Juan
Fonte: Instituto de Geología, UNAM Publicador: Instituto de Geología, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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36.47%
A regional-residual separation process has been applied to aeromagnetic data observed over southern California and the Baja California Peninsula. The 3D analytic signal amplitude computed from the residual magnetic anomalies is intense and delineates a strip ~60 km wide and ~1200 km long characterized by short-wavelength and high amplitude anomalies, that extends from southern California southward nearly to the tip of the Baja California Peninsula. Known iron-oxide-copper-gold (IOCG) ore deposits are for the most part located in the northern portion of the strip, and its eastern boundary closely follows the magnetite-ilmenite boundary. The amplitude and continuity of regional magnetic anomalies, which suggests an almost continuous belt of magnetized rocks, supports a hypothesis suggesting that the western margin of the Baja California Peninsula evolved as an island arc that was accreted to the western margin of North America in Cretaceous time. Inverse modeling of the long-wavelength regional magnetic anomalies indicates that two nearly continuous belts of magnetized rocks, of mafic to intermediate composition, extend from southern California to the La Paz fault. The boundary between these two belts is located near the Bahía de Sebastián Vizcaíno...