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Emplacement mechanisms and structural influences of a younger granite intrusion into older wall rocks - a principal study with application to the Goetemar and Uthammar granites. Site-descriptive modelling SDM-Site Laxemar  

International Nuclear Information System (INIS)

The c. 1.80 Ga old bedrock in the Laxemar-Simpevarp area, which is the focus of the site investigation at Oskarshamn, is dominated by intrusive rocks belonging to the c. 1.86-1.65 Ga Transscandinavian Igneous Belt (TIB). However, the site investigation area is situated in between two c. 1.45 Ga old anorogenic granites, the Goetemar granite in the north and the Uthammar granite in the south. This study evaluates the emplacement mechanism of these intrusions and their structural influence on the older bedrock. Field observations and structural measurements indicate that both the Goetemar and the Uthammar granites are discordant and have not imposed any significant ductile deformation on their wall-rocks. The apparent conformity of geological contacts and fabrics in the wall rocks and the southern margin of the Goetemar granite is coincidental and inherited from the pattern of Svecokarelian deformation of the TIB. However, interpretation of regional aeromagnetic data suggests that the granites occur within a broad, NNE-SSW trending linear belt, pointing to deep seated tectonic control on their generation, ascent and emplacement. Thermochronology indicates that the granites were emplaced at depths between 4 and 8 km into brittle wall rocks. The 3-D shape of the Goetemar and Uthammar plutons has been investigated by 2.75D forward modelling of the residual gravity anomalies due to both granites. Both granites are associated with strong residual gravity anomalies of up to -10 mgal. Constraints on the geometry of the plutons at the surface are provided from surface geology maps and several deep boreholes located on or close to the model profiles. A further variable in the gravity modelling is introduced by either allowing the upper contact of the plutons to assume the most suitable orientation to produce the best fit between the modelled and observed gravity ('unconstrained models') or by forcing the near surface orientation of the contacts to be vertical ('constrained models'). The unconstrained model profiles for both plutons are characterized by gently outward dipping upper contacts to depths ?1 km, gently inward dipping lower contacts and a thin, centrally located root extending to depths of 5 to 10 km. However, this geometry is not supported by available boreholes, which do not penetrate the upper contact of the Goetemar pluton as predicted by the models. The constrained models are consistent with borehole data. They characterize the plutons as having vertical contacts in the upper 500 to 1,000 m, a 1,000 to 1,500 m thick mid-level body with outward dipping upper and horizontal and lower contacts, respectively, and broad roots extending to depths of ?4 km. Preliminary observations and gravity modelling results indicate that the Goetemar and Uthammar granites are discordant plutons with geometries most consistent with punched laccoliths, with some modification due to floor subsidence due to root development. Their vertical and lateral dimensions fall in the upper range for laccoliths and lower range for plutons as defined by recent data compilations. Their emplacement required elastic bending and eventual failure of roof rocks that was likely accompanied by reactivation of pre-existing fractures and shear zones and possibly the creation of new brittle fractures. Cooling and crystallization of the granites resulted in thermal resetting of the wall rocks and the establishment of a transient hydrothermal system, now recorded by fracture filling mineral assemblages

2008-01-01

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Emplacement mechanisms and structural influences of a younger granite intrusion into older wall rocks - a principal study with application to the Goetemar and Uthammar granites. Site-descriptive modelling SDM-Site Laxemar  

Energy Technology Data Exchange (ETDEWEB)

The c. 1.80 Ga old bedrock in the Laxemar-Simpevarp area, which is the focus of the site investigation at Oskarshamn, is dominated by intrusive rocks belonging to the c. 1.86-1.65 Ga Transscandinavian Igneous Belt (TIB). However, the site investigation area is situated in between two c. 1.45 Ga old anorogenic granites, the Goetemar granite in the north and the Uthammar granite in the south. This study evaluates the emplacement mechanism of these intrusions and their structural influence on the older bedrock. Field observations and structural measurements indicate that both the Goetemar and the Uthammar granites are discordant and have not imposed any significant ductile deformation on their wall-rocks. The apparent conformity of geological contacts and fabrics in the wall rocks and the southern margin of the Goetemar granite is coincidental and inherited from the pattern of Svecokarelian deformation of the TIB. However, interpretation of regional aeromagnetic data suggests that the granites occur within a broad, NNE-SSW trending linear belt, pointing to deep seated tectonic control on their generation, ascent and emplacement. Thermochronology indicates that the granites were emplaced at depths between 4 and 8 km into brittle wall rocks. The 3-D shape of the Goetemar and Uthammar plutons has been investigated by 2.75D forward modelling of the residual gravity anomalies due to both granites. Both granites are associated with strong residual gravity anomalies of up to -10 mgal. Constraints on the geometry of the plutons at the surface are provided from surface geology maps and several deep boreholes located on or close to the model profiles. A further variable in the gravity modelling is introduced by either allowing the upper contact of the plutons to assume the most suitable orientation to produce the best fit between the modelled and observed gravity ('unconstrained models') or by forcing the near surface orientation of the contacts to be vertical ('constrained models'). The unconstrained model profiles for both plutons are characterized by gently outward dipping upper contacts to depths approx1 km, gently inward dipping lower contacts and a thin, centrally located root extending to depths of 5 to 10 km. However, this geometry is not supported by available boreholes, which do not penetrate the upper contact of the Goetemar pluton as predicted by the models. The constrained models are consistent with borehole data. They characterize the plutons as having vertical contacts in the upper 500 to 1,000 m, a 1,000 to 1,500 m thick mid-level body with outward dipping upper and horizontal and lower contacts, respectively, and broad roots extending to depths of approx4 km. Preliminary observations and gravity modelling results indicate that the Goetemar and Uthammar granites are discordant plutons with geometries most consistent with punched laccoliths, with some modification due to floor subsidence due to root development. Their vertical and lateral dimensions fall in the upper range for laccoliths and lower range for plutons as defined by recent data compilations. Their emplacement required elastic bending and eventual failure of roof rocks that was likely accompanied by reactivation of pre-existing fractures and shear zones and possibly the creation of new brittle fractures. Cooling and crystallization of the granites resulted in thermal resetting of the wall rocks and the establishment of a transient hydrothermal system, now recorded by fracture filling mineral assemblages

Cruden, Alexander R. (Dept. of Geology, Univ. of Toronto (Canada))

2008-12-15

3

Uranium potential of the younger granites of Egypt  

International Nuclear Information System (INIS)

The post-tectonic Pan-African younger granites of Egypt are characterized by abnormal radioactivity. Several plutons of these granites in the Eastern Desert, host a variety of rare metal mineralizations including uranium. Two younger granite plutons, namely El Missikat and El Erediya, in the central part of the Eastern Desert, host siliceous vein-type uranium mineralization, which is structurally controlled by faults and their feather joints associated with NE and NNE trending shear zones. The Gattar granite pluton, at the northern part of the Eastern Desert, hosts vein-type uranium mineralization associated with molybdenite. At the southern part of the Eastern Desert, Um Ara granite pluton hosts uranium as disseminated unconformity contact type. Pitchblende is the primary mineral, while secondary uranium minerals are mainly: uranophane, ?-uranophane, soddyite and renardite. Small amounts of pyrite, chalcopyrite, galena, sphalerite, molybdenite and violet fluorite are present in association with the uranium mineralization in the mineralized zones. Present data suggest an origin by hydrothermal fluids derived from the granitic magma. Redistribution by circulating meteoric water may have taken place as evidenced by widespread alteration, particularly silicification. Exploratory mining resulted in clarifying the possibility of the extension of the uranium mineralization zone laterally and in depth. The estimation of the uranium potentiality of the four younger granite plutons is 14000 tons uranium as speculative resources. (author). 25 refs, 1 fig., 1 tab

1992-06-01

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Petrogenesis of selected A-type granitic intrusions from Central Eastern Desert of Egypt  

Science.gov (United States)

The Pan-African orogeny in the Arabian-Nubian Shield was terminated by intrusion of A-type granites (~ 595 Ma; Greenberg, 1981) and its volcanic equivalents. Subsequent to the intrusions of these granitic bodies the shield was exhumed. Eroded A-type granite pebbles were found in the molasse sediments that were deposited in intermountain basins. Therefore the A-type granites provide information about the last stage of the Pan-African geochemical system. Preliminary whole-rock geochemical data of three granitic intrusions (Kadabora, Um Naggat and El shiekh Salem) from the Central Eastern Desert of Egypt; indicate that all of them are peraluminous and with A-type characteristics. These intrusions show low CaO content (average 0.43 %wt), high FeOT/MgO ratio (10.46-121.88), high Na2O+K2O (average 8.04 %wt), marked enrichment of high field strength elements (Y, Nb and Ga except Zr), depletion in MgO (0.01-0.11 %wt) and with low concentration of Sr and Ba. The studied granitoids were emplaced in within plate tectonic regime. References: Greenberg, J.K. (1981): Characteristic and origin of Egyptian younger granites. Bull. Geol. Soc. Am. Part 1, v.92: 224-232.

Hassan, Tharwat; Asran, Asran; Amron, Taha; Hauzenberger, Christoph

2014-05-01

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Uranium in the Niger-Nigeria younger granite province  

International Nuclear Information System (INIS)

In Niger, uranium occurs in upper Palaeozoic and lower Mesozoic continental sedimentary basins west of the Air Mountains, but the source of the uranium had not been identified. Geochemical studies and fission-track observations on alkaline ignimbrites preserved in two Palaeozoic anorogenic centres in Air show that uranium is concentrated in the matrix and on secondary iron-oxide coatings surrounding lithic and crystal fragments. Based on variable Th/U ratios and degree of oxidation, it is concluded that the original ignimbrite field was enriched in uranium, but that a considerable proportion was leached during the weathering of the volcanic pile. Tectonic uplift, anorogenic magmatism, followed by weathering and erosion of the volcanic cover, with sedimentation in nearby continental basins, have all contributed to the development of uranium mineralization in Niger. The petrological and geochemical similarities between the Palaeozoic ring complexes in Niger and the Nigerian Mesozoic ring structures suggest that sedimentary uranium deposits may also be found in Nigeria if the tectonic and sedimentological controls were favourable. Enriched concentrations of uranium have been discovered in the exposed granitic roof zones of the Nigerian subvolcanic centres, with Th/U ratios approaching unity. (author)

1982-01-01

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U-Pb conventional dating compared to SHRIMP of the Santa Barbara Granite Massif, Younger Granites Suite of Rondonia, Brazil  

International Nuclear Information System (INIS)

The Santa Barbara Granite Massif is part of the Younger Granites of Rondonia (998 - 974 Ma) and is included in the Rondonia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated with the late-stage unit. U-Pb monazite conventional dating of the early-stage Serra do Cicero facies and late-stage Serra Azul facies yielded ages of 993 +- 5 Ma and 989 +- 13 Ma, respectively. Conventional multigrain U-Pb isotope analyses of zircon demonstrate isotopic disturbance (discordance) and the preservation of inherited older zircons of several different ages and thus yielded a 207 Pb/206 Pb weighted-mean age of 978 +- 13 Ma. The textural complexity of the zircon crystals of the Santa Barbara facies association, the variable concentrations of U, Th and Pb, as well as the mixed inheritance of zircon populations are major obstacles to using conventional multigrain U-Pb isotopic analyses. Sm-Nd model ages and epsilonNd(T) values reveal anomalous isotopic data, attesting to the complex isotopic behaviour within these highly fractionated granites. Thus, SHRIMP U-Pb zircon and conventional U-Pb monazite dating methods are the most appropriate to constrain the crystallization age of the Sn-bearing granite systems in the Rondonia Tin Province. (author)

2002-12-01

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Sequential granite emplacement: a structural study of the late Variscan Strzelin intrusion, SW Poland  

Science.gov (United States)

The Strzelin Massif in SW Poland (Central European Variscides) records a protracted igneous evolution, with three main magmatic stages: (1) tonalitic I, (2) granodioritic and (3) tonalitic II/granitic. In the northern part of this Massif, the Strzelin intrusion proper comprises three successively emplaced rock types: a medium-grained biotite granite (303 ± 2 Ma), a fine-grained biotite granite (283 ± 8 Ma) and a fine-grained biotite-muscovite granite; based on field evidence, the third variety postdates both types of the biotite granites. The structural data from the three granites, including their parallel, approximately E-W striking and steeply dipping lithological contacts and ENE-WSW trending subhorizontal magmatic lineations, suggest that the emplacement of all three successive granite varieties was controlled by an active, long-lived strike-slip fault, striking ESE-WNW, with a dextral sense of movement. After the emplacement of the youngest biotite-muscovite granite, the intrusion underwent brittle extension which produced "Q joints" striking NNW-SSE to N-S and dipping at 55-70° WSW to W, and showing evidence of broadly N-S directed sinistral displacements. The structural observations, supported by new geochronological data, indicate that the internal structure of the composite granitoid intrusion, including the faint magmatic foliation and lineation, formed in a long-lived strike-slip setting, different from the subsequent, post-emplacement extensional tectonics that controlled the development of brittle structures.

Oberc-Dziedzic, Teresa; Kryza, Ryszard; Pin, Christian; Madej, Stanis?aw

2013-07-01

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Oxygen isotope geochemistry of the Granite Harbour Intrusives, Wilson Terrane, Northern Victoria Land, Antarctica  

International Nuclear Information System (INIS)

The oxygen and strontium isotope compositions of the Cambro-Ordovician granitoids cropping out in the Wilson Terrane (Granite Harbour Intrusives-GHI) constrain the petrological evolution of the magmatism in Antarctica, related to the Ross Orogeny. The measured ?18OWR values of three intrusives define three different compositional groups: the metaluminous rocks (MAG), with ?18OWR ranging from 6.9 (olivine gabbro) to 11.4 %o (monzogranite); the unaltered peraluminous granites (PAG), having ?18OWR values ranging from 10.6 to 13.2 %o, and the foliated peraluminous leucogranites (SKG), characterized by ?18OWR values above 14 %o. The analysis of equilibrium mineral assemblages indicates that the high ?18OWR values are magmatic and unaffected by low-temperature processes. A few peraluminous granites sampled in the vicinity of Cenozoic intrusions show anomalously low ?18OWR, due to meteoric-hydrothermal alteration. The isotopic data indicate that the coeval and spatially related metaluminous mafic and felsic intrusives forming the GHI were not comagmatic: the mafic and intermediate rocks were likely derived from lower crustal contamination of a pristine basaltic magma; their ?18OWR values were also increased during emplacement, due to the interaction with the adjacent 18O-rich hydrous felsic magmas (mixing). Oxygen isotope data indicate that the crustal sources producing the granite harbor intrusives were not homogeneous: the felsic metaluminous intrusives were produced by partial melting of fertile rock with possible igneous origin, whereas partial melting of a metapelitic source rock is claimed for the genesis of the peraluminous granites. (author)

2002-01-01

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Three Paleoproterozoic A-type granite intrusions and associated dykes from Kainuu, East Finland  

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Full Text Available Mafic and felsic intrusive rocks aged 2.5–2.4 Ga have been observed over a large area in eastern and northern Finland, as well as in adjacent northwestern Russia. We describe three granite intrusions and associated dykes from Kainuu, Finland, that belong to this bimodal magmatic event. All these three granites show clear A2-type chemical affinities with high Y/Nb, HREE, Fe/Mg, Ga and Nb. Two of the intrusions, Rasinkylä and Pussisvaara, were dated at 2425±3 and 2427±3 Ma, respectively, using thermal ionisation mass spectrometry utilizing the chemical abrasion method (CA-TIMS. CA-TIMS ages are supported by single-grain age determinations obtained by using Laser Ablation Multicollector Inductively Coupled Plasma Mass Spectrometer (LA-MC-ICPMS. New data on the previously described Rasimäki granite from southern Kainuu is presented, including an age of 2389±5 Ma obtained with LA-MC-ICPMS. The variable magnetite content of the granites is proposed to reflect the differences in the oxidation state of the source, which in our interpretation is the local Archean lower crust. Partial melting and the emplacement of the granites occurred in an extensional environment. Heat for the partial melting was provided by mafic magmas under and intraplating the extended crust.

Hannu Huhma

2010-12-01

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The Rio Dourado Intrusive Suite - 1.88 Ga A-type Granite - Southeastern Amazonian Craton - Mato Grosso - Brazil  

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Full Text Available The Rio Dourado Intrusive Suite (RDIS is composed of granitic rocks which are exposed in the southeastern AmazonCraton, Central Amazon Province. These granites intruded into the Paleoproterozoic granites of the Vila Rica IntrusiveSuite. The predominantly pyroclastic felsic volcanic rocks of the Iriri Group are coeval and spatially associated with theintrusive granites. Petrographic studies allow us to divide the Rio Dourado granites into: biotite granites, amphibole-bearingbiotite granites and granophyric granites. Modal compositions range from monzo to syenogranites. The oxidized A-typegranite is characterized by FeO/FeO+MgO ranging from 0.8 - 0.95, high contents of FeOT and low contents of CaO, as wellas peraluminous composition. In the tectonic discrimination diagrams, samples of these granites plot in the post-collisionalfield. REE patterns show enrichment in the LREE relative to HREE and negative Eu anomalies. Negative anomalies ofTa and Nb, as well as depletion in the HREE, features which are typical of A-type granites of post-collisional settings, are observed in multi-element diagrams,. Ce, Yb, Nb and Ga contents are transitional between those of A2 and A1-type granites. U-Pbzircon dating by TIMS yielded an age of 1876 ± 39, whereas negative values of ?Nd (-3 to -10 and model ages (TDM between 2.6 and2.8 Ga indicate it was formed by re-melting of older (possibly Archean crust.

Márcia Aparecida de Sant’Ana Barros

2011-04-01

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Evaluation of the radiological consequences of a human intrusion in a granite formation  

International Nuclear Information System (INIS)

The methodology used in France for the evaluation of the radiological consequences associated to a nuclear waste repository in a deep geological formation is the deterministic one. This means that, in addition to the calculations in connection with the ''normal'' scenario, a limited number of ''altered'' scenarios, representing the different families of plausible scenarios and corresponding to the most important consequences resulting from there families, have to be taken into account. Among them, the human intrusion scenario is an important one. In a study performed inside the CEC PAGIS project and also for a french expert group (Goguel group) which carried out a methodologic work for the national site selection procedure, results concerning the quantification of the radiological consequences of a human intrusion have been obtained without attempting at the evaluation of its probability. The intrusion time ranged from 1 000 to 100 000 years and different contamination scenarios were taken into account. It was assumed that the intrusion led to the creation of a 100 cubic meters edge cubic cavity in the immediate vicinity to the repository. Using the description of the Auriat site realized for PAGIS, the calculation was performed in three steps: - calculation of the evolution of the repository until the intrusion time, - computation of the supposed instantaneous new flow distribution after the intrusion, - computation of the dose rate, using the mean volumic activity in the cavity walls and the outgoing flow rate. Three exposure scenarios were considered: - a worker in the mine exposed to by external irradiation and contaminated by inhalation of radioactive materials, -an animal drinking in the vicinity during the mining operation, - gardening after the closure of the mine. With the exception of the worker scenario (the dose rate may reach 10-2 Sv/year, which is comparable with the normal exposure in a granite mine), the other dose rates were found to be quite low

1989-06-05

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Neoproterozoic granites of the Lajeado intrusive suite, north-center Brazil: A late Ediacaran remelting of a Paleoproterozoic crust  

Science.gov (United States)

In north-central Brazil, a number of granite plutons, which intrude Paleoproterozoic gneiss-granulite terrains of the Goiás Massif, crop out along a thermal axis parallel to the Transbrasiliano Lineament. Single zircon lead evaporation ages from three granitic bodies span between 552 and 545 Ma. Sm-Nd model ages (TDM) vary between 2.1 and 1.7 Ga and negative ?Nd(0.55 Ga) values between -10 and -13 show that Paleoproterozoic crust was involved in the genesis of these granites. These plutons, which form the Lajeado Intrusive Suite are part of an important Ediacaran magmatic event in central-northern of the Tocantins Tectonic Province, composed of metaluminous to slightly peraluminous granites with geochemical characteristics similar to A-type granites, whose crystallization occurred under low water activity during magmatic emplacement. The granitic intrusive bodies are related to a crustal extensional/transtensional tectonic event at the end of the Neoproterozoic. They may have connection with the granitic plutons of similar age (0.56-0.52 Ga) in northwestern Ceará state, on the other side of the Paleozoic Parnaíba Basin in northwest of Borborema Province, along the Transbrasiliano Lineament.

de Sousa Gorayeb, Paulo Sergio; Chaves, César Lisboa; Moura, Candido Augusto Veloso; da Silva Lobo, Luciano Ricardo

2013-08-01

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Kuznechensky intrusion of K-rich porphyric granites: U-Pb data and tectonic position (Baltic shield)  

International Nuclear Information System (INIS)

For studying the conditions and age range of formation of the Kuznechensky intrusion (Baltic shield) the U-Pb isotope dating of zircon and monazite within granites of the intrusion mentioned was performed. Bearing in mind the morphological characteristics of the zircon studied, suggesting its magmatic origin, the age value obtained, equal to 1874 ± 4 mln. years, is referred to the time of the massif crystallization. The monazite age (1851 ± 5 mln. years) reflects the period of its U-Pb system closing and corresponds to metamorphism time

2004-10-01

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Characteristics of pegmatoidal granite exposed near Bayalan, Ajmer district, Rajasthan  

Science.gov (United States)

The study involves the characterization of pegmatoidal granite, southeast of Beawar, Ajmer district, Rajasthan. Earlier researchers had described this granite as part of the BGC, basement to the Bhim Group of the Delhi Super Group rocks. However, the present study indicates that it is younger than the rocks of Bhim Group of South Delhi Fold Belt, into which it is intrusive. The intrusion is structurally controlled and the outcrop pattern is phacolithic. The granite had intruded post-D2 deformation of the Delhi orogeny along the axial planes of D2 folds. The intrusion has also resulted in the formation of a contact aureole about the calc gneisses.

Dasgupta, Nilanjan; Pal, Taritwan; Sen, Joydeep; Ghosh, Tamoghno

2011-08-01

15

Interactions between extensional shear zones and syn-tectonic granitic intrusions: the example of Ikaria Island (Cyclades, Greece)  

Science.gov (United States)

The Aegean domain is an ideal place to investigate the development of Metamorphic Core Complex (MCC) and to study the role of syn-tectonic granites on their development. MCCs of the Aegean domain are dynamically associated with a few major detachments, especially the North Cycladic Detachment System (NCDS) and the West Cycladic Detachment System (WCDS), which have accommodated a large part of the crustal thinning during the Oligocene and Miocene. The NCDS extends toward the East within the Simav Detachment that has exhumed the northern high-temperature part of the Menderes massif. The transition between the NCDS and the Simav Detachments is located above a major tear in the Aegean slab whose effects on lithospheric deformation are far from understood. The Aegean granitoids were emplaced during the Middle Miocene within a zone of high-temperature during the episode of slab tearing and recorded increments of extensional tectonics within this complex zone. Ikaria Island (Cyclades, Greece) is a metamorphic dome intruded by three Miocene granitoid plutons (one I-type intrusion, two S-type ones) including the largest pluton of the Aegean domain. However, geometry, structures and kinematics are still debated with several recent yet conflicting studies. We have reconsidered the geology of Ikaria to settle the geological and structural context of these plutons. The intrusion depth of the Raches granite has been estimated at 10-15 km by the Al-in-hornblende barometer. Our field study has led to the identification of two major structures: the Gialiskari and Kalamos detachments, which we interpret as belonging to the NCDS. A study of deformation in the granites has highlighted a continuum during cooling that can be described in three stages: i) magmatic deformation, ii) high-temperature ductile deformation from late magmatic stage until complete crystallization of the granite, iii) low-temperature brittle deformation. Throughout this evolution, the same top-to-the-NE shearing deformation was active below the Gialiskari and Kalamos detachments with a progressive localization of strain. A scenario of this deformation continuum below the Gialiskari-Kalamos detachments through the ductile-brittle transition is proposed. The granites were emplaced while the exhumation of the Ikaria high-temperature metamorphic dome was already underway. We conclude that the crustal-scale detachment has controlled the localization of the intrusion and not the opposite.

Laurent, Valentin; Beaudoin, Alexandre; Jolivet, Laurent; Arbaret, Laurent; Augier, Romain; Rabillard, Aurelien

2014-05-01

16

Deep-seated geology of the granite intrusions at the Soultz EGS site based on data from 5 km-deep boreholes  

Energy Technology Data Exchange (ETDEWEB)

The petrographic model for the deep-seated geology at the Soultz-sous-Forets Enhanced Geothermal System (EGS) site in the Rhine Graben, France, was revised on the basis of data from 5 km-deep wells. Several types of granite and sub-facies were characterized through thin-section analysis of drill cuttings. Various datalogs were studied to correlate them with petrography. The new geological model of the Soultz site is made up of a massive porphyritic granite that shows some paleo-weathering at its top, overlain by about 1400 m of Mesozoic and Tertiary sediments. Between 2700 and 3200 m depth, the same granite is highly fractured and hydrothermally altered. Below this zone, the granite is less fractured and is very rich in biotite and amphibole. Starting at 4700 m depth is a younger, fine-grained, two-mica and amphibole-rich granite that intrudes into the porphyritic granite. (author)

Hooijkaas, Gerridina R. [Departments of Petrology and Isotope Geochemistry, Institute of Earth Sciences, Vrije Universiteit, De Boelelaan 1085, NL 1081 HV, Amsterdam (Netherlands); Genter, Albert; Dezayes, Chrystel [French Geological Survey, BRGM, 3 Avenue Claude Guillemin, BP6009, F-45060 Orleans Cedex 2 (France)

2006-10-15

17

Gravimetric modeling of the Parguaza granitic intrusion, Guyana Precambrian Shield, southwestern Venezuela using geochronological constraints  

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Full Text Available A combined gravimetric and geochronological interpretation of the Parguaza intrusion in the Guayana shield, southwestern Venezuela, indicates that there is a pattern of inverse cooling within this pluton. Based on a positive correlation between Rb/Sr whole rock apparent ages and residual Bouguer anomaly, density contrasts over the Parguaza intrusion are linked to temperature and crystallization of mineral phases. This hypothesis is supported by density measurements on hand samples and by independent geochemical evidence. A simple 2D gravity model is constrained by surface geology, Rb/Sr apparent ages (whole rock and residual Bouguer anomalies. Gravimetric modeling implies a model of horsts and grabens that accounts for inverse zoning of the intrusion as a result of geological and age contrasts across the faults.

Oscar Mirón-Valdespino

2004-12-01

18

Contact metamorphism, partial melting and fluid flow in the granitic footwall of the South Kawishiwi Intrusion, Duluth Complex, USA  

Science.gov (United States)

The footwall of the South Kawishiwi Intrusion (SKI) a part of the Mesoproterozoic (1.1 Ga) Duluth Complex consists of Archean granite-gneiss, diorite, granodiorite (Giant Range Batholith), thin condensed sequences of Paleoproterozoic shale (Virginia Fm.), as well as banded iron formation (Biwabik Iron Fm). Detailed (re)logging and petrographic analysis of granitic footwall rocks in the NM-57 drillhole from the Dunka Pit area has been performed to understand metamorphic processes, partial melting, deformation and geochemical characteristics of de-volatilization or influx of fluids. In the studied drillhole the footwall consists of foliated metagranite that is intersected by mafic (dioritic) dykes of older age than the SKI. In the proximal contact zones, in the mafic dykes, the orthopyroxene+clinopyroxene+plagioclase+quartz+Fe-Ti-oxide+hornblende±biotite porphyroblasts embedded in a plagioclase+K-feldspar+orthopyroxene+apatite matrix indicate pyroxene-hornfels facies conditions. Migmatitization is revealed by the euhedral crystal faces of plagioclase and pyroxene against anhedral quartz crystals in the in-situ leucosome and by the presence of abundant in-source plagioclase±biotite leucosome veinlets. Amphibole in the melanosome of mafic dykes was formed with breakdown of biotite and implies addition of H2O to the system during partial melting. Towards the deeper zones, the partially melted metatexite-granite can be characterized by K-feldspar+plagioclase+quartz+ortho/clinopyroxene+biotite+Fe-Ti-oxide+apatite mineral assemblage. The felsic veins with either pegmatitic or aplititic textures display sharp contact both to the granite and the mafic veins. They are characterized by K-feldspar+quartz±plagioclase±muscovite mineral assemblage. Sporadic occurrence of muscovite suggest local fluid saturated conditions. Emplacement of gabbroic rocks of the SKI generated intense shear in some zones of the granitic footwall resulting in formation of biotite-rich mylonites with lepidoblastic texture. High modal content of syn-tectonic biotite in these shear zones indicate involvement of large amount of fluids during deformation. Apatite is an omnipresent accessory mineral in all rock types, with up to 1-3% modal proportion. Crystal habit is columnar or rarely needle-like. XCl/XF and XOH/XF ratios of apatite were compared with depth in the drillhole and in relation to the host rock type. Apatite in the metagranite and in the mafic dyke is fluorine-rich (XFgranite?1,27-1,63; XFmafic dyke?1,51-1,83) and their XCl/XFgranite?0,083 to 0,051 and XCl/XFmafic dyke?0,051 to 0,044 ratios decrease towards the distal parts of the contact. Apatite in biotite-rich mylonite, as well as in the porphyroblasts of mafic dykes, is extremely depleted in chlorine- and hydroxyl-anions (XCl/XFmylonite?0,02 and XOH/XFmylonite?0,14), whereas apatite in felsic dykes and in the in-source leucosome are enriched in hydroxyl and chlorine relative to fluorine (XCl/XFfelsic vein?0,21 and XOH/XFfelsic vein?0,37). These variations suggest release of chlorine enriched fluids from the partially melted contact zones and movement and enrichments of these fluids in migration channels of partial melts. It has been for a long time accepted that fluids emerging from the metamorphosed Virginia Formation played an essential role in the formation of the Cu-Ni sulphide and PGE mineralization at the bottom of the gabbroic intrusions in the northwestern marginal zones of the Duluth Complex. Our study proves that the granitic footwall was also an important source of fluids and melts. We acknowledge the Austrian Science Found (FWF P23157-N21) to A. Mogessie for the financial support.

Benko, Z.; Mogessie, A.; Molnar, F.; Severson, M.; Hauck, S.; Lechler, P.; Arehart, G.

2012-04-01

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The Blackwater Intrusion of the Grampian Orogeny: Implications for the Younger Basics and the Tectonic-Metamorphic Zonation of the Grampian Terrane, NE Scotland  

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The Dalradian Supergroup of NE Scotland hosts the classic Buchan low-pressure high-temperature metamorphic domain, as well as a suite of substantial ~470Myr syn-orogenic mafic intrusions (the 'Younger Basics') and a set of major, steeply-inclined shear zones which deform both the Dalradian country rocks and the Younger Basics. The Blackwater mafic intrusion is situated within one such shear zone, the Portsoy-Duchray Hill Lineament (PDHL), which runs SW inland from the coast at Portsoy and corresponds with the westernmost limit of Buchan metamorphism. Occupying a position between the Appin and Argyll Groups, the Blackwater Intrusion is emplaced at a deeper structural level than other more extensively studied Younger Basics to the East towards Aberdeen (such as the Insch Intrusion) and North along the PDHL (such as the Portsoy Gabbro). Uniquely for a Younger Basic mass, it is also in contact with older Dalradian meta-basic rocks, the somewhat enigmatic Blackwater Formation. A well as examining the Blackwater Intrusion, this study presents new evidence pertaining to the history of the Younger Basics and the PDHL, and their place within the Grampian Orogeny. The Blackwater Intrusion has an elongate shape roughly parallel to the strike of the surrounding Dalradian rocks, covers ~9km2 and mainly comprises blue-grey gabbro with scattered serpentinised ultramafic zones. Both the gabbro and serpentinite generally have massive texture, although some evidence of cm-scale modal layering (interpreted as cumulate texture) is present the north of the intrusion. It is in contact to the east with psammites, schists and meta-basic extrusives of the Argyll Group Blackwater Formation, and to the west with the Appin Group Glenfiddich Pelite Formation. Evidence for shearing is widespread, with sheared microstructures in pelites and meta-basites, mylonitised meta-sediments adjacent and parallel to the NW contact of the gabbro and vertical/sub-vertical NE-SW trending shear zones within the gabbro and serpentinite. Also, several apparently sheared m-scale pegmatite dykes cross-cut the gabbro, also with a NE-SW orientation. There is no evidence for significant hornfelsing adjacent to the intrusion. Collectively, this evidence suggests that the mass is largely tectonically emplaced, and that the PDHL was active both during and after emplacement of the Blackwater Gabbro. Meta-basic rocks of the Blackwater Formation have been interpreted as pillow basalts erupted from a submarine rift associated with the breakup of Rodinia. Vesicles are abundant in some outcrops, consistent with an extrusive origin. Determination of ?34S values in sulphide minerals and REE element profiles of the meta-basalts should further test the origin of these undated units. I will also present fluid inclusion data from mylonites adjacent to the intrusion and Cr-spinel-specific elemental data bearing on the nature of the original ultramafic melt composition, the mantle peridotite source, and tectonic setting of the Younger Basic bodies.

Webb, Gareth; Raub, Timothy

2014-05-01

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From explosive breccia to unidirectional solidification textures: magmatic evolution of a phosphorus- and fluorine-rich granite system (Podlesí, Krušné hory Mts., Czech Republic)  

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The Podlesí granite stock in western Krušné hory Mts. represents the most highly fractionated part of the late Variscan Nejdek-Eibenstock pluton. Internal fabric of the stock has been studied in several boreholes up to 350 m deep. The stock is composed of two tongue-like bodies of albite-protolithionite-topaz granite (stock granite) coalesced at depth, which were emplaced into Ordovician phyllite and biotite granite of younger intrusive complex (YIC) of the Nejdek pluton. The uppermost par...

Breiter K

2002-01-01

 
 
 
 
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Feldspathization in the Loket monzogranite - possible influence of granites of the younger intrusive complex (Karlovy Vary intrusion). In: MAEG - 10 Challenges to Chemical Geology. Abstracts.  

Czech Academy of Sciences Publication Activity Database

. ?eská geologická spole?nost. Ro?. 42, ?. 3 (1997), s. 66. ISSN 1210-8197.[Meeting Association of European Geological Societies /10./ Challenges to Chemical Geology. 01.09.1997-05.09.1997, Karlovy Vary]Grant CEP: GA ?R GA205/93/0343

Novák, Ji?í Karel; Tvrdý, J.; Novák, M. (ed.); Janoušek, V. (ed.); Košler, J. (ed.)

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Determination of concentrations and isotopic ratio of uranium in groundwaters drawn from two deep wells drilled in granitic rocks belonging to Itu intrusive suite  

International Nuclear Information System (INIS)

This paper presents the first results obtained in the determination of dissolved uranium concentrations and (234U/238U) activity ratios of groundwaters drawn from two deep wells drilled in granitic rocks belonging to Itu Intrusive Suite, which is located at eastern Sao Paulo State. One of the wells, whose groundwaters have been analyzed, is located in Salto Town, while the other one is located in Itu Town. The groundwater sampling is monthly and begun on September, 2004, in order to investigate possible sazonal variations. The alpha spectrometry technique, associated with isotopic dilution method, has been used for these determinations. The data obtained up to now show that the groundwaters from Salto present uranium concentrations significantly lower ((0.098 ± 0.007) - (0.17 ± 0.01) ng/g) than those from Itu ((0.22 ± 0.02) - (0.31 ± 0.02) ng/g). The 234U and 238U isotopes of the investigated groundwaters from both wells are in radioactive disequilibrium, with (234U/238U) activity ratios systematically higher than unity. Although the groundwaters from Salto well are characterized by low 234U and 238U specific activities they present higher (234U/238U) activity ratios than those from Itu. The observed differences on the behavior of uranium concentrations and (234U/238U) activity ratios in the groundwaters from the two wells are very probably due to the large variety of granitic rocks from Itu Intrusive Suite, which are characterized by distinct uranium abundances. (author)

2005-09-02

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Cryogenian transpression and granite intrusion along the western margin of Rodinia (Mt. Abu region): Magnetic fabric and geochemical inferences on Neoproterozoic geodynamics of the NW Indian block  

Science.gov (United States)

The Mt. Abu batholith in NW India comprises variably deformed porphyritic, granophyric to medium-grained granites and granite gneisses. They are intruded by rhyolitic and mafic dykes; the latter also mark the terminal magmatic phase in this batholith. Granitoids and rhyolitic dykes form a coherent group; petrographic and geochemical characteristics indicate high level intrusion of felsic magma generated from high temperature melting of a lower crustal source. Geochemical similarity, spatial contiguity and coeval emplacement (766 to 763 Ma) of Mt. Abu granitoids with the Neoproterozoic (770 to 750 Ma) Malani Igneous Suite (MIS) underline that both are related to the same thermal event with Mt. Abu batholith as southeastern continuity of the MIS. Anisotropy of magnetic susceptibility data shows parallel fabric orientation in all granitoid types (NE trend, steep SW dip) as well as in a prominent shear zone (Delwara Shear Zone) along the western margin of the batholith with continued deformation during and after the emplacement of granitic magma as inferred from deformation of late-stage mafic dykes. Including coeval shear zones and associated melting in the region NE of Mt. Abu shear-controlled magma generation and ascent along a > 50 km NE trending corridor (Mt. Abu-Sirohi fault zone) is inferred. Structural elements and microstructural criteria (steep foliations, vertical lineations, dextral displacement) indicate a transpressional setting for this Cryogenian event. In regional geodynamic context the Mt. Abu-MIS can be regarded as northeastern continuation of the Neoproterozoic (800-700 Ma) magmatic belt extending from northern Madagascar, the Seychelles into NW India. This magmatic belt, located along the western margin of supercontinent Rodinia, was formed during eastward subduction of the Mozambique Ocean. Transpressional forces responsible for shaping the structural architecture in the Mt. Abu-Sirohi region were most likely induced during closure of the Mozambique Ocean and related translation of the Marwar craton.

de Wall, Helga; Pandit, Manoj K.; Dotzler, Ramona; Just, Jana

2012-07-01

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234U and 238U behavior in groundwaters extracted from fractured granitic bodies of Itu intrusive suite (SP-Brazil)  

International Nuclear Information System (INIS)

In this work the first results of the determination of dissolved uranium concentrations, as well as (234U/238U) activity ratios of groundwaters extracted from deep wells drilled in fractured rocks of Itu Intrusive Suite (Sao Paulo State) are presented. The analytical method used in this study is alpha spectrometry, that allows determining uranium activity concentrations, as well as (234U/238U) activity ratios with high precision and accuracy levels. (author)

2007-10-05

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Occurrence of ? 1Ga Jambugoda granite in Aravali Craton, a tectonic significance  

International Nuclear Information System (INIS)

The granites and gneisses of southern parts of Aravali Mountain Belt (AMB), NW India, are referred to as Godhra Granite and Gneiss and have an intrusive relationship with the surrounding metasedimentary rocks, which belong to the Lunavada Group in the north and Champaner Group in the south (Fig.1). These two groups comprise the younger part of the Aravali Supergroup. Two granite varieties, coarse and fine, are commonly observed and occupy an area of about 5000 km2. The coarse-grained granite is grayish and porphyritic in nature. It consists phenocrysts of feldspar and quartz, and abundant biotite. Fine grained granite is commonly found to occur in association with coarse grained granite; at places, the former is seen to have an intrusive relationship with the latter. Available age data information is scant, and is mainly based on Rb-Sr wholerock methods. In spite of these limitations, the available data indicate that the granitoids might comprise two or more age groupings. Published Rb-Sr ages for various plutons include Mt. Abu granite 735 ± 15 Ma , Godhra granite 955 ± 20 Ma, Sendra granite 966 ± 250 Ma, and Ambaji granite ?1228 Ma. Godhra granite assumes importance due to its proximity to the Son-Narmada North Fault (SnF) and is believed to have formed during the growth of the Indian shield in Mesoproterozoic times. Further ?1 Ga granites play a vital role in global tectonics therefore an attempt has been made to decipher various episodes of granitic evolutionary events in these parts of the subcontinent

2009-11-01

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The Veikkola granite area in southern Finland: emplacement of a 1.83-1.82 Ga plutonic sequence in an extensional regime  

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Full Text Available Four granite intrusions and coeval small enderbite intrusions, belonging to the lateorogenic (1850–1820 Ma magmatism of the Svecofennian orogeny, are described in the Veikkola area of southern Finland. The granites are leucocratic, heterogeneous and characterizedby abundant garnet. The oldest granite is layered whereas the younger ones are more homogeneous. Geochemically the granites are peraluminous and have high contents of SiO2 (71–76 wt.%. Their major and minor element composition varies significantly but the REE patterns are fairly similar. Garnet mainly crystallized from melt but some garnet in the granites may be restitic. Garnet composition is relatively constant implying slow equilibration with the melt. In addition to garnet-bearing felsic layers in the oldest granite, the granites are crosscut by garnet-bearing dikes and veins. The layers, dikes and veins are higher in REE and Fe/Mg than the host granites and are considered partial melts from the granites. The abundant garnet in the felsic layers, dikes and veins crystallized from melt. Thermobarometry calculations indicate 3.5 – 5 kbar and ~650–700 °C estimates for crystallization of the felsic layers in the oldest granite whereas the host granite yields ~1.5 kbar higher pressure. The granites were probably derived by dehydration melting of layered, metagreywacke-dominated rocks. Melting was fluid-absent both during generation of the granites and during formation of the felsic layers, dikes and veins. The oldest granite (1850 Ma was emplaced at mid-crustal depth before extensional deformation. Layering in the oldest granite is regarded as the result of deformation-induced remelting of the host granite at a higher crustal level, during protracted extension and progressive regional metamorphism. The otherthree granites and the enderbite were emplaced at a late stage of extension, at or close to the peak of metamorphism (1.83 – 1.82 Ga.

Matti Kurhila

2008-01-01

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Extreme U-Th disequilibrium in rift-related basalts, rhyolites and granophyric granite and the timescale of rhyolite generation, intrusion and crystallization at Alid volcanic center, Eritrea  

Science.gov (United States)

Rhyolite pumices and co-erupted granophyric (granite) xenoliths yield evidence for rapid magma generation and crystallization prior to their eruption at 15.2 ?? 2.9 ka at the Alid volcanic center in the Danikil Depression, Eritrea. Whole-rock U and Th isotopic analyses show 230 Th excesses up to 50% in basalts <10 000 years old from the surrounding Oss lava fields. The 15 ka rhyolites also have 30-40% 230Th excesses. Similarity in U-Th disequilibrium, and in Sr, Nd, and Pb isotopic values, implies that the rhyolites are mostly differentiated from the local basaltic magma. Given the (230 Th/232Th) ratio of the young basalts, and presumably the underlying mantle, the (230Th/232Th) ratio of the rhyolites upon eruption could be generated by in situ decay in about 50 000 years. Limited (???5%) assimilation of old crust would hasten the lowering of (230Th/232Th) and allow the process to take place in as little as 30 000 years. Final crystallization of the Alid granophyre occurred rapidly and at shallow depths at ???20-25 ka, as confirmed by analyses of mineral separates and ion microprobe data on individual zircons. Evidently, 30 000-50 000 years were required for extraction of basalt from its mantle source region, subsequent crystallization and melt extraction to form silicic magmas, and final crystallization of the shallow intrusion. The granophyre was then ejected during eruption of the comagmatic rhyolites. ?? 2006 Oxford University Press.

Lowenstern, J. B.; Charlier, B. L. A.; Clynne, M. A.; Wooden, J. L.

2006-01-01

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Uranium and thorium distribution in the Contreberg granite, Darling  

International Nuclear Information System (INIS)

Two plutons of young granite, intrusive into other members of the Cape Granite suite, occur to the northwest and southeast of Darling, Western Cape Province. In spite of their comparable temporal and structural positions in the granite series, the two granites differ considerably in textural and compositional properties, making a comparative study desirable. Thus the Contreberg granite was compared with the Klipberg granite. The average radioelement content was lower in the Contreberg granite than in the Klipberg granite. For the Contreberg granite the average values are 6,0 ppm U_3O_8 and 28 ppm ThO_2

1984-07-09

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Quartz And Zircon as markers of the magmatic-hydrothermal evolution of the Antônio Vicente Granite, Velho Guilherme Intrusive Suite, Carajás Province  

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Full Text Available the Antônio Vicente Granite, Carajás Province, by scanning electron microscope-cathodoluminescence (SEM-CL images. In the lessevolved rocks, containing amphibole and biotite, well developed anhedral to subhedral, luminescent and intensely fractured crystalsdominate, named Qz1. Hydrothermal fluids that percolated the granite modified the magmatic quartz (Qz1 into Qz2 and Qz3 throughprocesses of alteration, dissolution and recrystallization, with these changes much more evident in the intensely altered syenograniterocks. Qz4 constitute medium-to-coarse grained crystals, usually luminescent and comparatively little fractured. Its occurrence is restrictedto strongly hydrotermalized syenogranite rocks and bodies of greisens, suggesting the beginning of the greisenization process.In the greisens, medium-to-coarse grained euhedral, concentrically zoned quartz crystals dominate, with typical features of hydrothermalorigin (Qz5. Fine crystals of zoned cassiterite (? 100 ?m are common and fill cavities in the types Qz4 and Qz5. Zircon crystalsdominantly anhedral, corroded, with the highest contents of Hf and the lower Zr/Hf ratios belong to more evolved and hydrothermallyaltered rocks and to associated greisens, both carriers of Sn mineralization. This fact suggests that the geochemical signature of zircon,especially Zr/Hf ratio, can be used for the preliminary assessment of metallogenic potential of tin granites.

Claudio Nery Lamarão

2013-06-01

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Magmatic evolution of topaz-bearing granite stocks within the Wiborg rapakivi granite batholith  

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This study brings new insights into the magmatic evolution of natural F-enriched peraluminous granitic systems. The Artjärvi, Sääskjärvi and Kymi granite stocks within the 1.64 Ga Wiborg rapakivi granite batholith have been investigated by petrographic, geochemical, experimental and melt inclusion methods. These stocks represent late-stage leucocratic and weakly peraluminous intrusive phases typical of rapakivi granites worldwide. The Artjärvi and Sääskjärvi stocks are multiphase intr...

Lukkari, Sari

2007-01-01

31

Geochronology of the Schurwedraai Alkali Granite and associated nepheline syenite and implications for the origin of the Vredefort structure  

International Nuclear Information System (INIS)

New Rb-Sr and Pb-Pb whole-rock and mineral age determinations indicate ages close to 2,2 Ga for the Schurwedraai Alkali Granite and associated nepheline syenite from the northwestern part of the collar around the Vredefort dome. The 2,2 Ga age is consistent with existing age data from another intrusion in the rim of the Vredefort structure and represents a significant upward revision of the age previously accepted for the Schurwedraai Granite. As such it removes the important constraint imposed by the synchronicity of the alkali magmatism and the Vredefort event on meteorite impact theories for the origin of the Vredefort structure. The younger overprint at approximately 2050 Ma can be interpreted to reflect either the age of the Vredefort event and associated deformation/alteration of the alkali intrusives or a thermal overprint related to the emplacement of the Bushveld Complex at this time. 48 refs., 9 figs., 2 tabs

1991-01-01

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Hepburn intrusive suite: Peraluminous plutonism within a closing back-arc basin, Wopmay orogen, Canada  

Science.gov (United States)

Within the Hepburn metamorphic-plutonic internal zone of the Wopmay orogen (Northwest Territories, Canada) there are two chronologically and petrologically distinct plutonic associations. The more voluminous of the two, the older 1.885 Ga Hepburn intrusive suite, includes rocks ranging in composition from gabbro to granite, peraluminous granite dominating. The younger 1.855 Ga neighboring Bishop intrusive suite (also gabbro to granite) represents the waning stages of a well-documented calc-alkaline arc, the Great Bear magmatic zone. The petrological distinctions between the two suites are all late-acquired features imposed primarily by contrasting environments of emplacement. Hepburn magmas were intruded within a closing, dominantly sedimentary, back-arc basin. Magma emplacement was synchronous with crustal imbrication, regional metamorphism, and translation of the basin-fill units onto Archean crust. Significant assimilation of sedimentary host rocks by the rising Hepburn magmas occurred, whereas the postregional metamorphism emplacement of the Bishop magmas precluded similar assimilation. The gabbroic contribution observed in the Hepburn intrusive suite is interpreted to reflect a mantle-derived precursor inherited from the back-arc rifting event that immediately preceded emplacement of the suite.

Lalonde, André E.

1989-03-01

33

High precision ages from the Torres del Paine Intrusion, Chile  

Science.gov (United States)

The upper crustal bimodal Torres del Paine Intrusion, southern Chile, consists of the lower Paine-Mafic- Complex and the upper Paine-Granite. Geochronologically this bimodal complex is not well studied except for a few existing data from Halpern (1973) and Sanchez (2006). The aim of this study is to supplement the existing data and to constrain the age relations between the major magmatic pulses by applying high precision U-Pb dating on accessory zircons and 40Ar/39Ar-laser-step-heating-ages on biotites from the Torres del Paine Intrusion. The magmatic rocks from mafic complex are fine to medium-grained and vary in composition from quartz- monzonites to granodiorites and gabbros. Coarse-grained olivine gabbros have intruded these rocks in the west. The granitic body is represented by a peraluminous, biotite-orthoclase-granite and a more evolved leucocratic granite in the outer parts towards the host-rock. Field observations suggest a feeder-zone for the granite in the west and that the granite postdates the mafic complex. Two granite samples of the outermost margins in the Northeast and South were analyzed. The zircons were dated by precise isotope-dilution U-Pb techniques of chemically abraded single grains. The data are concordant within the analytical error and define weighted mean 206/238U ages of 12.59 ± 0.03 Ma and 12.58 ± 0.01 Ma for the two samples respectively. A 40Ar/39Ar-age for the second sample yield a date of 12.37 ± 0.11 Ma. Three 40Ar/39Ar -ages of biotites were obtained for rocks belonging to the mafic complex. A hbl-bio- granodiorite from the central part, approximately 150 m below the subhorizontal contact with the granite, gives an age of 12.81 ± 0.11 Ma. A hbl-bio-granodiorite and an olivine-gabbro west of the feeder-zone date at 12.42 ± 0.14 Ma and 12.49 ± 0.11 Ma, respectively. The obtained older age of 12.81 Ma for the granodiorite in the central part is consistent with structural relationships of brittle fracturing of the mafic complex by the granite and we conclude that some parts of the mafic complex were emplaced before the granite. The well defined 206/238U-age for zircons and the slightly younger 40Ar/39Ar -ages for biotites of both rock suites show that emplacement and cooling of the Torres del Paine Intrusion took place in a relatively short time-frame. Halpern, 1973, Geological Society of America Bulletin, 84/7: 2407-2422. Sanchez et.al., 2006. V SSAGI, Punta del Este, April 2006.

Michel, J.; Baumgartner, L.; Cosca, M.; Ovtcharova, M.; Putlitz, B.; Schaltegger, U.

2006-12-01

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The mafic - granitic connection of the Torres del Paine laccolith, Patagonia  

Science.gov (United States)

We have conducted a field, petrological and geochronological study of a bimodal intrusive complex from the Torres del Paine laccolith, Patagonia, Chile. The goal of this study is to understand how various types of mafic rocks evolve at shallow pressure and how they are related in space and time to the various granitic sheets. From field relations it is evident that the granite intruded as a series of sheets, with the oldest pulse on top and the youngest at the base of the laccolith. High precision U-Pb dating on single zircons (Michel et al. Geology 2008) is in agreement with field relations and yielded 12.59±0.02 for the oldest and 12.51±0.03 for the youngest granite dated. The granites are underlain by a series of mafic sills composed of hornblende-gabbros and diorites. We distinguish two types of hornblende gabbros that are chemically similar but clearly different with respect to their mineral crystallization sequence. However, the contacts between the different mafic rocks are ductile as illustrated by mafic enclaves in diorite or ascent of small diorite diapirs into overlaying hornblende gabbros, indicating (near-) simultaneous emplacement of most of the mafic rocks. Bulk rock chemistry suggests that the mafic and granitic rocks follow a high - K calcalkaline to shoshonitic differentiation trend. Liquid compositions calculated from Laser Ablation ICP-MS trace element analysis of cumulate minerals indicate that the mafic rocks crystallized from a K-rich basaltic to shoshonitic magma. Intercumulus minerals show equilibrium with a granodioritic to granitic melt, that is similar to Paine granites. Preliminary isotope dilution - thermal ionization mass spectrometry on zircons from one gabbro and one diorite yielded 12.40±0.04 and 12.447±0.013 Ma, which is about 60'000 years younger than the youngest granite dated so far. This would suggest that a large volume of the laccolith grows downwards, with younger and more mafic sheets at the bottom of the complex. The youngest granites that cut the entire complex, however, await precise dating. Michel et al. (2008), Geology 36/6, 459-462

Leuthold, J.; Muntener, O.; Baumgartner, L.; Putlitz, B.; Ovtcharova, M.; Schaltegger, U.; Chiaradia, M.

2009-12-01

35

Ad Duwayhi, Saudi Arabia: Geology and geochronology of a neoproterozoic intrusion-related gold system in the Arabian shield  

Science.gov (United States)

The Ad Duwayhi gold deposit, located in the east-central part of the Arabian shield, is the newest gold discovery in Saudi Arabia. Exploration to date has identified a gold resource of greater than 1 million ounces (oz) with significant potential for expansion. Gold mineralization was closely associated, in time and space, with emplacement of a late- to postorogenic, intracrustal, northwest-oriented granite body (659 ?? 7 Ma) and comagmatic square quartz porphyry (646 ?? 11 Ma), a hypabyssal and perhaps younger phase of the granite. Mineralization was largely confined to northeast-striking, southeast-dipping fault zones. Hydrothermal alteration consisted of early biotitic alteration overprinted by sericitic alteration. Sericitic alteration was coincident with gold mineralization and produced a quartz-sericite-carbonate-pyrite-rutile mineral assemblage, found both as vein fill and wall-rock alteration products. Mineralization styles, in the following general paragenetic sequence, include (1) quartz-molybdenite veins in and near the granite stock, (2) low-grade gold-bearing quartz vein breccia in and along the margins of the granite stock, (3) gold-bearing stockwork and sheeted quartz veins, and (4) massive to banded gold-rich tabular quartz veins. The gold-bearing stockwork, sheeted, and tabular veins are generally spatially associated with square quartz porphyry dikes and more distal to the granite stock. Mineralized zones at Ad Duwayhi are characterized by low sulfide and base metal content and gold/silver ratios of approximately 6/1. Gold shows no significant correlation with other metals, except lead, and moderate correlation with silver. Re-Os dating of molybdenite from a quartz-molybdenite vein and a tabular quartz vein with cogenetic gold produced robust ages of 655.6 ?? 2.7 and 649.9 ?? 2.3 Ma, respectively, documenting that gold mineralization and crystallization of granite and square quartz porphyry were, within uncertainty, coeval events. This age correlation combined with granite textural features, the presence of unidirectional solidification textures in granite and square quartz porphyry, and the nature and time-space distribution of mineralization styles, all indicate that mineralization evolved in and near the interface between a crystallizing magma and the surrounding rocks and, thus, is consistent with an intrusion-related genesis. In light of our findings at Ad Duwayhi, a reassessment of similar intrusion-hosted deposits in the Arabian shield is warranted, and areas of late- to postorogenic plutonism, particularly in the Afif composite terrane, should be considered prospective for intrusion-related gold systems. ??2004 by Economic Geology.

Doebrich, J. L.; Zahony, S. G.; Leavitt, J. D.; Portacio, Jr. , J. S.; Siddiqui, A. A.; Wooden, J. L.; Fleck, R. J.; Stein, H. J.

2004-01-01

36

Petrochemistry and Rb-Sr isotopic study of bandal granites, district Kulu, Himachal Pradesh  

International Nuclear Information System (INIS)

Bandal granites which form the subject matter of the present study occur as a concordant body of batholithic size and cover an area of about 500 sq. km. consider these granites to be the result of granitization of arkose and pelitie rocks. Whereas treats them as intrusive into the Banjar Formation, recognized two components i.e. foliated and non-foliated which made the Bandal pluton the latter is intrusive into the former. This gave an isochron age of 1220±100 Ma for the foliated granite. This paper presents the results of a petrochemical and Rb-Sr isotopic studies of these granites with a view to understand their petrogenesis

2004-10-01

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Maurim intrusive suite: a calc-alkacic batholite zoned of catarinense shield  

International Nuclear Information System (INIS)

The geological survey of the Florianopolis Sheet (SG.22-Z-D-V) identified and characterized a calc-alkacic multi-intrusive and polydiapiric suite that occurs as a granitic batholite roughly concentric in texture and composition. This co-magmatic plutonic sequence is intrusive in the granite-gneissic basement of amphibolite facies, with which it was formerly confounded. The initial magmatic terms, put-in-place at the marginal portions of the batholite, are represented by quartz-diorites and tonalites (Forquilha Tonalites), followed by granodiorites (alto da Varginha Granodiorite), granodiorites to monzonites (Rio das Antas Granite) and completed by an inner portions of porphyritic monzonites (Sao Pedro de Alcantara Granite). The identifications of the compositional zoning that results from the development of the magmatic chamber is based on the examination of 74 rock samples that were analysed for major and minor oxides and trace elements (Ba, F, Li, Mo, Sn, W, Y, Rb, Nb, Zr and Sr). The treatment of these data shows the portions where mantle fractions predominate as well as the others where crustal meltings dominate, what demonstrates an origin by in situ differentiation processes, fractioning and different degrees of magmatic mixing. Geochronologic dating by Rb/Sr, K/Ar and U/Pb methods show isochronic and conventional ages of 600 to 700 m.y. that roughly are in accord with the temporal progress towards the younger felsic phases, putting this suite in the Upper Proterozoic age. The initial Sr sup(87) / Sr sup(86) ratios, around 0.710, point to a crustal origin with variable mantle contribution to these rocks. (author)

1990-11-01

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Zircon geochronology and Hf-O isotope geochemistry from granites in the Iapetus Suture Zone in Ireland and the Isle of Man  

Science.gov (United States)

Late Caledonian syn- to post-orogenic granites located in the Iapetus Suture Zone (ISZ) in Ireland and Britain have been related to A-type subduction and possible slab breakoff [1] following the Laurentia-Avalonian collision. Lack of reliable age data (especially in Ireland) has inhibited petrogenetic investigations of these rocks. Hence, ion microprobe U-Pb and oxygen isotope analyses as well as LA-MC-ICPMS Lu-Hf isotopic measurements on zircons from Irish and Isle of Man granites have been undertaken to provide better constraints on this enigmatic episode of the Caledonian Orogeny. Four stages of Late Caledonian granitic magmatism (c. 435, 417, 410 and 394 Ma) are indicated by U-Pb dating of oscillatory-zoned magmatic zircons. The Crossdoney, Kentstown, Drogheda and Ballynamuddagh granites together with a rhyolite from Glenamaddy have yielded U-Pb concordia ages, interpreted as intrusion-ages, between 419.9 ± 4.3 Ma (Glenamaddy) and 415.8 ± 2.0 Ma (Crossdoney) with a weighted average of 417.5 ± 0.9 Ma (MSWD = 1.3). The Glenamaddy Granite - which intruded the Glenamaddy Rhyolite - yielded an age of 410 ± 2.1 Ma. In addition, the Rockabill Granite yielded a younger age of 393.9 ± 1.9 Ma, whereas the Carnsore Granite yielded an older age of 434.6 ± 1.9 Ma. Inherited zircons (487 to 453 Ma) occur in several of the granites, and are interpreted to have been derived from Ordovician arc magmatic rocks accreted within the ISZ. A younger group of c. 440 Ma inherited zircons occurs in the c. 417 Ma Crossdoney and Ballynamuddagh granites. These grains could be related to continued or renewed Silurian arc magmatism. Hf-O isotopic measurements on the dated zircon grains range between -2 and +7 ?Hfi units and 5.5 to 8.5 o ?18O. These are interpreted to indicate the contribution of juvenile mantle melts - possibly derived from the Ordovician arc - to some of the granites. Significant heterogeneities in zircon oxygen isotopes in at least four of the granites further suggest the involvement of isotopically distinct protoliths. The Dhoon and Foxdale granites in the Isle of Man were previously regarded to be of Late Caledonian age. Surprisingly, zircons from these granites yielded concordant U-Pb ages of 455.6 ± 2.1 Ma (Dhoon) and 455.9 ± 2.1 Ma (Foxdale), respectively. Inherited cores are of Meso- and Palaeoproterozoic age. Hafnium isotopic analyses of the dated magmatic zircon rims from both intrusions are slightly more radiogenic than those from the Late Caledonian granites. Their ?18O values range between 5.5 to 7.5 o. The Isle of Man granites are now suggested to be the plutonic equivalents of a Late Ordovician (Caradocian) volcanic arc generated in the Iapetus Ocean. [1] Atherton & Ghani (2002), Lithos 62, 65-85.

Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; McConnell, Brian; Buhre, Stephan

2014-05-01

39

Analysis of microporous structure in granite  

Energy Technology Data Exchange (ETDEWEB)

The water saturation method and the mercury intrusion porosimetry were applied to the characterization of micropores in granite. Although these techniques have been commonly used to characterize pores in rocks, special cares are needed for precise measurement of the porosity and the pore size of low-porosity rocks. The water saturation method uses water-saturated weight, submerged weight and dry weight of the rock samples to calculate the porosity. The errors accompanied in the measurements of the water-saturated weight often bring about significant errors in determination of the porosity. Analysis of drying curves of water-saturated weight enabled precise measurements of porosity. In the mercury intrusion porosimetry, a major part of the error in the porosity determination is due to rough surfaces of the sample. For the porosity determination described in this paper, the rock sample was cut into rectangular parallelepipeds, instead of crushing, to reduce the surface roughness. The detection limit of the mercury intrusion is also a cause for the error for low-porosity samples. Five samples whose total volume was 6ml were simultaneously put in the measurement cell of the porosimeter to increase the amount of intruding mercury. These effort made reliable characterization of pores in a granite from Inada, Ibaraki, Japan and pores in a granite from the Underground Research Laboratory (URL) of Atomic Energy of Canada Limited, Manitoba, Canada. The distribution of the pore diameter of these granites were nearly logarithmic normal. The porosity of Inada granite was determined to be (0.49{+-}0.07)% with the modal diameter of 160nm. The micropores of a few tens to a few hundred nanometers in width were observed by SEM. The URL granite had the porosity of (0.40{+-}0.10)% and the modal diameter of 340nm. The assumptions in applying the Fickian diffusion theory to the diffusion of ions in porous materials were confirmed for these granites. (J.P.N.)

Yamaguchi, Tetsuji; Isobe, Hiroshi; Nakayama, Shinichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-03-01

40

Analysis of microporous structure in granite  

International Nuclear Information System (INIS)

The water saturation method and the mercury intrusion porosimetry were applied to the characterization of micropores in granite. Although these techniques have been commonly used to characterize pores in rocks, special cares are needed for precise measurement of the porosity and the pore size of low-porosity rocks. The water saturation method uses water-saturated weight, submerged weight and dry weight of the rock samples to calculate the porosity. The errors accompanied in the measurements of the water-saturated weight often bring about significant errors in determination of the porosity. Analysis of drying curves of water-saturated weight enabled precise measurements of porosity. In the mercury intrusion porosimetry, a major part of the error in the porosity determination is due to rough surfaces of the sample. For the porosity determination described in this paper, the rock sample was cut into rectangular parallelepipeds, instead of crushing, to reduce the surface roughness. The detection limit of the mercury intrusion is also a cause for the error for low-porosity samples. Five samples whose total volume was 6ml were simultaneously put in the measurement cell of the porosimeter to increase the amount of intruding mercury. These effort made reliable characterization of pores in a granite from Inada, Ibaraki, Japan and pores in a granite from the Underground Research Laboratory (URL) of Atomic Energy of Canada Limited, Manitoba, Canada. The distribution of the pore diameter of these granites were nearly logarithmic normal. The porosity of Inada granite was determined to be (0.49±0.07)% with the modal diameter of 160nm. The micropores of a few tens to a few hundred nanometers in width were observed by SEM. The URL granite had the porosity of (0.40±0.10)% and the modal diameter of 340nm. The assumptions in applying the Fickian diffusion theory to the diffusion of ions in porous materials were confirmed for these granites. (J.P.N.)

1997-03-01

 
 
 
 
41

Pórfiro granítico Mojotoro (Salta: ¿Una cúpula intrusiva o un dique en el ciclo pampeano? The Mojotoro granitic porphyry (Salta: An intrusive roaf or a dike in the Pampean Cycle?  

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Full Text Available El pórfiro granítico Mojotoro, constituye la cúpula de un plutón epizonal, emplazado en un área geológica bien conocida, de la Formación Puncoviscana, en las inmediaciones de la ciudad de Salta (24º47´44,9"S - 65º21´35,9"W, 1.304 m s.n.m.. Sin bien se carece de determinaciones geocronológicas, los caracteres geológicos regionales y situación estratigráfica de no alcanzar los niveles del Grupo Mesón, sugieren edades pampeanas, correspondientes a la orogenia tilcárica. Los caracteres petrográficos corresponden a pórfiros graníticos, con fenocristales de feldespato potásico, acompañados por cuarzo, plagioclasa y biotita. Las rocas han sufrido intensa sericitización, caolinización y limonitización. Asimismo muestra esferulitas recristalizadas, inclusiones fluidas y fragmentos de granófiro, que indican emplazamiento somero, con rápido intercrecimiento conjunto de cuarzo en una masa de feldespato alcalino hipersolvus. La susceptibilidad magnética es baja con valores de 0,11 x 10-3 SI, típicos para granitos corticales formados a partir de protolitos metasedimentarios.The Mojotoro porphyritic granite is located close to the city of Salta (24°47´44,9"S - 65°21´35,9"W, 1304 m.a.s.l., at Cerro Mojotoro in the Eastern Cordillera. The pluton is emplaced in the Puncoviscana Formation (Late Precambrian-Early Cambrian, a lithological unit composed mainly of greenish pelites. The Puncoviscana Formation is covered unconformably by Cambrian quartzites of the Meson Group. Stratigraphic relationships of the granite indicate a Pampean age and emplacement during the Tilcaric orogenic phase. Petrographically it is a porphyritic granite with K-feldspar phenocrysts accompanied by quartz, plagioclase and biotite. The rock is strongly altered by sericitization, kaolinization, and limonitization. Likewise, the granite exhibits recrystalized spherules, fluid inclusions and granophyric fragments, indicative of shallow emplacement, with fast intergrowth of quartz in a mass of K-feldspar hypersolvus. Low magnetic susceptibility, with values of 0.11x10-3 SI, is typical of cortical granite that was formed from a metasedimentary protolith.

A.J. Toselli

2005-06-01

42

Magmatic constraints on localization of natural stone deposits in the Vehmaa rapakivi granite batholith, southwestern Finland  

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Full Text Available The 1580–1570 Ma old Vehmaa rapakivi granite batholith was studied with the aim to define the geological constraints for localization of natural stone deposits in the batholith. The batholith comprises four roughly concentric granite intrusions from the margin inwards: pyterlite, coarse-grained porphyritic rapakivi granite and two types of medium-grained porphyritic rapakivi granite. Also porphyry aplite and even-grained rapakivi granite occur. The batholith has intruded as a succession of pulses of subhorizontal sheet-like intrusions conceivably through repeated cauldron subsidence. Natural stone quarries are confined only to certain intrusions within the batholith. We show that the medium-grained porphyritic granite body in the centre of the batholith comprises two almost identical but different intrusions, with only slightly different appearances: the inner (IG and the outer (OG granite. The quarries are confined to the outer intrusion which has an appearance more attractive to the market than that of the inner intrusion. The localization of the natural stone deposits in the Vehmaa batholith is a result of the magmatic history of the batholith, producing intrusions of different appearances with different commercial potential.

Olavi Selonen

2011-08-01

43

Uranium in granites  

International Nuclear Information System (INIS)

Recent research activities of the Canadian Uranium in Granites Study are presented in 18 papers and 3 abstracts. 'Granites' is used as a generic term for granitoids, granitic rocks, and plutonic rocks

1980-11-25

44

Gamma-spectrometric surveys in differentiated granites. II: the Joaquim Murtinho Granite in the Cunhaporanga Granitic Complex, Parana, SE Brazil  

International Nuclear Information System (INIS)

Detailed mapping at the NW corner of the large Neo proterozoic Cunhaporanga Granitic Complex (CGC), Parana state, SE Brazil, redefined the Joaquim Murtinho Granite (JMG), a late intrusion in CGC with an exposed area of about 10 km2, made up mainly by evolved 'alaskites' (alkali-feldspar leuco granites). This unit is in tectonic contact with the Neoproterozoic-Eocambrian volcano-sedimentary Castro Group, to the W, and is intrusive into other less evolved granitic units of the CGC to the E. Petrographically, JMG shows mainly mesoperthite and quartz, with subordinate amounts of altered micas and some accessory phases, mainly zircon. The equi to inequigranular granites are usually deformed with cataclastic textures, are often brecciated, and may have miarolitic structures. Formation of late albite, sericite, carbonate and hematite was caused by deuteric and hydrothermal alteration. A gamma-ray spectrometric survey at 231 stations which measured total counts (TC), Ueq K%, eU ppm and eTh ppm was used to construct several direct and derived maps. Compared to neighboring units the JMG has significant anomalies, especially in the TC, %K, eTh and eU maps, although the differences are less obvious in some derived maps. These evolved granites are enriched in these three elements. Geochemical behavior of K, Th and U is used to analyse the results observed in maps. Enhanced weathering under a subtropical climate with moderate to high average temperatures and heavy rainfall affects mainly feldspars and biotite, and may also destabilize most U and Th-bearing accessory phases. Th is most likely retained in restite minerals in soils, being relatively immobile, while part of U may migrate as uranyl ion in oxidizing media. K is especially affected by feldspar alteration to K-free clays (mainly kaolinite), and may be completely leached. Gamma-ray spectrometric methods are valid tools to study facies in granitic rocks, especially in those that are enriched in K, Th and U. (author)

2009-01-01

45

Host minerals for uranium and thorium in the Cape granite  

International Nuclear Information System (INIS)

The uranium and thorium in Cape granite reside chiefly in trace minerals. The principle host minerals differ much from pluton to pluton. The large composite Khubus pluton in the Richterveld is composed of a central body of syenite surrounded by various types of granite. The granites are usually very low in dark minerals. According to autoradiographic results, the bulk of the uranium and thorium in the Khubus pluton is situated in the zircon, rather than in the sphene, apatite and fluorite. In many intrusives of the Cape granite suite most of the uranium is situated in a single host mineral such a zircon, xenotime, sphene or even uraninte. The most important thorium host mineral is monazite. The radio-element host mineral spectrum is unique for each different intrusive

1986-11-01

46

Melting granites to make granites  

Science.gov (United States)

Large-scale partial melting in the continental crust is widely attributed to fluid-absent incongruent breakdown of hydrous minerals in the case of pelites, greywackes and meta-mafic rocks. Granite is a far more common rock in the continental crust, but fluid-absent hydrate-breakdown melting is unlikely to result in significant melting in granites because of their low modal abundance of mica or amphibole. Experiments show that fluid-present melting can produce ~30% melt at low temperatures (690°C). Thus, granites and leucogranites can be very fertile if H2O-present melting occurs via reactions such as plagioclase + quartz + K-feldspar + H2O = melt, because of their high modal proportions of the reactant phases. Our study investigates the Kinawa Migmatite in the São Francisco Craton, southeastern Brazil. This migmatite is derived from an Archaean TTG sequence and can be divided into; 1) pink diatexites, 2) leucosomes, 3) grey gneisses and 4) amphibolites. The migmatite records upper-amphibolite to beginning of granulite facies metamorphism in a P-T range from 5.1-6.6 kbar and ~650-780°C. Pink diatexites are the most abundant rocks, and their appearance varies depending on the amount of melt they contained. Three types are recognised: residual diatexites (low melt fraction (Mf)), schlieren diatexites (moderate Mf) and homogeneous diatexites (high Mf). They are very closely related spatially in the field, with mostly transitional contacts. There is a sequence with progressive loss of ferromagnesian minerals, schollen and schlieren through the sequence to the most melt-rich parts of the diatexites as magmatic flow became more intense. There are fewer ferromagnesian minerals, thus the melt becomes cleaner (more leucocratic) and, because the schlieren have disaggregated the aspect is more homogeneous. These parts are texturally similar to leucogranites in which the biotite is randomly distributed and pre-melting structures are completely destroyed. The likely protolith for the migmatites was a leucocratic granodiorite (with modal K-feldspar up to 30% and biotite up to 5%), and from geochemical modelling the degree of partial melting ranged from 0.21 to 0.25. Furthermore, the residual diatexites show a complementary low modal proportion, or even absence, of K-feldspar, but an increase in modal plagioclase, quartz (up to 56 and 37% respectively) and biotite (5-16%). This suggests that the melting reaction did not involve biotite and that plagioclase and quartz were in excess. As result the melt generated is fairly leucocratic, and most of the mafic phases in it are inherited. Anatectic melts in the Kinawa Migmatite were mildly metaluminous and distinctly leucocratic (A/CNK from 0.97 to 1.01; SiO2 from 72.8 to 75.65%; (FeOT+MgO+TiO2) from 0.49 to 2.3%). Since most granites have a higher (FeOT+MgO+TiO2), additional processes must add the "mafic component" to these melts before they form plutons.

Carvalho, Bruna B.; Sawyer, Edward W.; Janasi, Valdecir de A.

2014-05-01

47

Review of engineering, hydrogeological and vadose zone hydrological aspects of the Lanseria Gneiss, Goudplaats-Hout River Gneiss and Nelspruit Suite Granite (South Africa)  

Science.gov (United States)

Three major basement granites of South Africa, viz. the Lanseria Gneiss of the Johannesburg Dome Granite, the Goudplaats-Hout River Gneiss and the Nelspruit Suite, are compared in terms of existing and new geotechnical and hydrogeological data. Typical weathering profiles based on landform and climate are deduced, denoting typical engineering and hydrogeological behaviour. Finally, the vadose zone behaviour of the basement granites are described with the aim on better understanding of the behaviour of these systems under variable saturation. Ephemeral hillslope wetlands, seepage lines and catenas are specifically addressed as associated hydrological influences, as well as the associated processes of translocation forming duplex soils and pedogenesis forming ferricrete. The final summarised findings depict low plasticity and expansiveness of granites with the most notable geotechnical influences being collapsibility, dispersive behaviour, seepage and difficult excavation. Hydrologically, secondary porosity prevails and younger structures or intrusions govern groundwater occurrence. The vadose zone comprises thick fractured rock to be included in modelling with the soil zone having saturated conductivity typically in the order of 1 × 10-4 to 1 × 10-5 m/d.

Dippenaar, Matthys A.; van Rooy, J. Louis

2014-03-01

48

Petrography and geochemistry of the topaz-bearing granite stocks in Artjärvi and Sääskjärvi, western margin of the Wiborg rapakivi granite batholith  

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Full Text Available The Artjärvi and Sääskjärvi granite stocks at the western margin of the Wiborg rapakivi batholith are multiphase rapakivi granite intrusions in which the most evolved phase is topaz-bearing granite. The Artjärvi stock is composed of porphyritic and even-grained biotite granite and even-grained topaz granite, and the Sääskjärvi stock comprises even-grained biotite granite and porphyritic topazgranite. The granites are metaluminous to peraluminous A-type granites, showing within-plate (WPG geochemical characteristics. The topaz granites from the Artjärvi and Sääskjärvi stocks are petrographically and geochemically similar to other topaz-bearing rapakivi granites in Finland. The anomalous geochemistry of the topaz granite is essentially magmatic; postmagmatic reactions have only slightly modified its composition. Greisen veins, some of which are mineralized, are widely found associated with the Artjärvi and Sääskjärvi stocks.The most characteristic feature of the Artjärvi granite stock is a stockscheider at the roof contact of the topaz granite. The stockscheider is composed of schlieren layering and pegmatite layers parallel to the contact. The most probable mechanism for the formation of the schlieren layering is velocity-gradient sorting parallel to the flow, which led to accumulation of mafic minerals along the upper contact of the topaz granite. Cooling and contraction of the topaz granite formed fractures parallel to the roof contact and the residual pegmatite magmas were injected along the fractures forming pegmatite layers. Textures like graphic intergrowths, aplitic groundmass and fan-shaped alkali feldspar crystals associated with the Artjärvi porphyritic biotite granite and pegmatite indicatecrystallization from undercooled magma. Miarolitic cavities found in the porphyritic biotite granite and topaz granite indicate at least local volatile saturation.

Sari Lukkari

2002-01-01

49

Rb-Sr, K-Ar and fission track ages for granites from Penang Island, West Malaysia: an interpretation model for Rb-Sr whole-rock and for actual and experimental mica data  

Science.gov (United States)

Penang Island represents the northwestern extension of the western magmatic belt of Peninsular Malaysia. Thirty-one samples of highly evolved biotite-and biotite-muscovite granites were used in an integrated study to unravel the complex magmatic, tectonic and cooling histories of these rocks. Highly distorted Rb-Sr whole-rock age patterns are evident. These are attributed to the partial post-magmatic Sr homogenization within the granite batholith which led to the rotation of isochrons towards younger ages and higher (87/86)Sr intercepts. The recognition of this mechanism allowed the establishment of a new Rb-Sr interpretation model. The intrusion ages of the granites can be extrapolated based on the evolutionary trend of the initial (87/86)Sr. Including the data of Bignell and Snelling, three episodes of granite emplacement at 307±8 Ma, 251±7 Ma and 211±2 Ma are suggested for Penang and the NW Main Range. The late-Triassic intrusive induced a hydrothermal conductive convection system which affected all the granites. It is considered to be responsible for the Rb-Sr whole-rock age distortion, the Rb-Sr and K-Ar biotite age resetting and the textural and mineralogical changes in the granites. The duration of the hydrothermal convections, deduced from the Rb-Sr whole rock ages, is about 6 Ma and 20 Ma in the northern and southern parts of Penang respectively. Fast regional cooling to 350±50°C within a time span of 1 3 Ma is recognized for the late-Triassic Feringgi intrusive from the mica ages, followed by a generally slow cooling rate of about 1°C/Ma. Fission track ages, in addition, indicate blockwise uplift along the N-S and NW-SE tending faults, thus resulting in the exposure of deeper crustal levels in southern and eastern Penang. A change in the tensional regime since Oligocene/Miocene, accompanied by a southwest tilting of the island, is indicated by the fission track apatite ages. Variable sometimes younger K-Ar, respectively Rb-Sr biotite ages mainly depend on the degree of hydrothermal overprint at different crustal levels. An increase of the reaction surface by grain size reduction influences Rb-Sr and K-Ar mica ages in similar ways, as has been demonstrated by experimental data.

Kwan, T. S.; Krähenbühl, R.; Jager, E.

1992-09-01

50

Mineral chemistry, petrology and geochemistry of the Sebago granite-pegmatite system, southern Maine, USA  

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The Permian (293 ± 2 Ma) Sebago Pluton is a homogeneous, two-mica granite situated in the Oxford pegmatite field, southwestern Maine. Surrounding the pluton is an area designated as the Sebago Migmatite Domain (SMD) dominated by metapelitic migmatites and diatexites with subordinate intrusions of heterogeneous, two-mica and biotite granites, pegmatitic leucogranites and granitic pegmatites. The Sebago Pluton plus the SMD formerly defined the extent of the Sebago Batholith. Mo...

Wise M; Brown C D

2010-01-01

51

EXPLOITATION OF GRANITE BOULDER  

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Full Text Available The processes of forming, petrography, features, properties and exploitation of granite boulders are described. The directional drilling and black powder blasting is the succesful method in exploitation of granite boulders (boulder technology.

Ivan Cotman

1994-12-01

52

U-Pb zircon ages of members of the Salem Granatic Suite along the northern edge of the Central Damaran Granite Belt  

International Nuclear Information System (INIS)

Porphyric Salem Suite granite rocks in the low-grade Northern Zone and adjoining portion of the high-grade Central Zone give respective ages of 589+- 40 and 546+- 30 m.y. (2 omnicron) which are indistinguishable within the limit of uncertainty. A complex, diachronous tectonic history is evident. Ages of deformation and granite intrusion in the Northern Zone and the coastal region of the Huab and Ugab Rivers appear to be similar. Deposition of the Mulden Group, the single intense phase of deformation and the low-grade metamorphism of the Northern Zone were completed between 550 and 600 m.y. ago and prior to the first granite intrusions. This was between 54 and 140 m.y. before completion of deformation in the adjoining, fundamentally different, high-grade, tectonically complex, granite-rich Central Zone. D1 in the southern Central Zone is older than 595 m.y. D2 may have been coeval in both the Northern and Central Zones, but a northward decrease in age across the Central Zone cannot be ruled out. D3 decreases in age northwards across the Central Zone and is at least 20 m.y. and may be as much as 120 m.y. younger in the north. The peak of metamorphism could have been coeval in the Northern and Central Zones. D3 in the northern Central Zone (479+- 16 m.y.) is the youngest major deformation event in the orogen. The Central Zone was finally thrust against and over the Northern Zone subsequent to D3 in the former

1983-01-01

53

Rb-Sr and Pb-Pb geochronological studies on the granite gneiss of Kuilapal, Purulia-Bankura Midnapore district, West Bengal  

International Nuclear Information System (INIS)

The number of younger granite plutons intruding the Singhbhum Mobile Belt (SMB) surrounding the Singhbhum-Orissa Craton, viz. Kuilapal granite on the East, Mayurbhanj granite, Soda granite, Arkasoni granite, Chakradharpur granite gneiss and Tamper kola granite on the west. Of these Kuilapal granite body is the largest. Besides small granite bodies intruding the low-grade meta sediments and meta volcanics which occur north of the Dalma volcanic belt. Petrographic and geochemical characters of the minor granite bodies south of Dalma volcanics are similar to those of Kuilapal granite, which is inferred to have been produced by shallow-level fractional crystallisation of a crustally derived granodiorite melt. Dominance of xenoliths in the Kuilapal granite suggest large-scale assimilation of crustal rocks. The radiometric ages vis-a-vis isotope geochemistry of the various granitoid plutons occurring within the mobile belt were used to constrain the evolutionary history of the SMB supracrustals. The Singhbhum Shear Zone which marks the boundary of the SMB with Singhbhum-Orissa Craton, shows multiple reactivation, the oldest being at ? 3.09Ga. Further phases of granite plutonism and/or shearing and mineralisation have been reported along this shear zone occurred in Palaeo-to Mesoproterozoic periods at ? 2.2, 1.8, 1.6-1.5, 1.4 and 1.0 Ga respectively. The present work pertains to the Rb-Sr and Pb-Pb whole rock geochronological studies on Kuilapal granite, which are intrusive into the metasediments of Singhbhum group in the tectonic setup of north Singhbhum Mobile Belt. Fourteen samples were collected, finely powdered form the homgenised representative which were processed further. The dissolution of the rock carried out in a class-100 clean chemical laboratory, followed by the elemental separation using exchange chromatography. The separated pure fractions of the elements were analysed on VG354 Thermal Ionisation Mass spectrometer for their isotopic ratios. The Rb-Sr data on ten samples define an isochron age of 1792±98 Ma, with an initial 87Sr/86Sr of 0.7064±0.0069 (MSWD = 13). The Pb isotopic data on these samples define a Pb-Pb isochron age of 1863 ± 80Ma (MlSWD =11.3) with a model ?1 value of 8.53±0.27. Both the Rb-Sr and the Pb-Pb ages are in agreement within the limits of experimental errors. Since the 87Sr/86Sr initial ratio and model ?1 value are higher than the contemporary mantle sources, the data indicate involvement of enriched crustal sources. This age obtained on Kuilapal granite can be taken as the age of one of those periods of reactivation which occurred during Palaeo-to Mesoproterozoic periods. (author)

2011-10-19

54

Thorite in an Apollo 12 granite fragment and age determination using the electron microprobe  

Science.gov (United States)

We present the first quantitative compositional analysis of thorite in a lunar sample. The sample, a granitic assemblage, also contains monazite and yttrobetafite grains, all with concentrations of U, Th, and Pb sufficiently high to determine reliably with the electron microprobe. The assemblage represents the first documented occurrence of these three minerals together and only the second reported occurrence of thorite in a lunar rock. Sample 12023,147-10 is a small, monomict rock fragment recovered from an Apollo 12 regolith sample. It comprises graphic intergrowths of K-feldspar and quartz, and plagioclase and quartz, along with minor or accessory hedenbergite, fayalite, ilmenite, zircon, yttrobetafite, thorite, monazite, and Fe metal. Thorite, ideally ThSiO4, occurs in the assemblage adjacent to quartz and plagioclase, and includes a 12% xenotime ([Y,HREE]PO4) component. From quantitative electron-probe microanalysis (EPMA) of Th, U, and Pb in thorite, assuming that all of the measured Pb is radiogenic, we calculate an age of 3.87 ± 0.03 Ga. Yttrobetafite and monazite, which contain lesser concentrations of U, Th, and Pb than the thorite, yield ages of 3.78 ± 0.06 Ga and 3.9 ± 0.3 Ga, respectively. These dates are consistent with formation of the granitic material around 3.8-3.9 Ga, possibly associated with, or after, the formation of the Imbrium basin. This age falls within a group of younger ages for granitic samples, measured mainly by ion microprobe analysis of zircon, compared to a suite of older ages, ca. 4.20-4.32 Ga, also from zircons (Meyer et al., 1996). A 3.8-3.9 Ga age may reflect an origin following the Imbrium event whereby granitic melt formed as a result of heating and melting, and was mobilized and emplaced along an Imbrium-related ring-fracture system. Silicic volcanic or exposed intrusive materials occur in several circum-Imbrium locations such as the Mairan and Gruithuisen Domes and in ejecta excavated by Aristarchus crater. Perhaps sample 12023,147-10 and some of the other granitic materials sampled at the Apollo 12 site represent rocks similar to the rocks that make up these large silicic rock occurrences.

Seddio, Stephen M.; Jolliff, Bradley L.; Korotev, Randy L.; Carpenter, Paul K.

2014-06-01

55

Earth's youngest exposed granite and its tectonic implications: the 10-0.8 Ma Kurobegawa Granite.  

Science.gov (United States)

Although the quest for Earth's oldest rock is of great importance, identifying the youngest exposed pluton on Earth is also of interest. A pluton is a body of intrusive igneous rock that crystallized from slowly cooling magma at depths of several kilometers beneath the surface of the Earth. Therefore, the youngest exposed pluton represents the most recent tectonic uplift and highest exhumation. The youngest exposed pluton reported to date is the Takidani Granodiorite (~ 1.4 Ma) in the Hida Mountain Range of central Japan. Using LA-ICP-MS and SHRIMP U-Pb zircon dating methods, this study demonstrates that the Kurobegawa Granite, also situated in the Hida Mountain Range, is as young as ~ 0.8 Ma. In addition, data indicate multiple intrusion episodes in this pluton since 10 Ma with a ~ 2-million-year period of quiescence; hence, a future intrusion event is likely within 1 million years. PMID:23419636

Ito, Hisatoshi; Yamada, Ryuji; Tamura, Akihiro; Arai, Shoji; Horie, Kenji; Hokada, Tomokazu

2013-01-01

56

Petrology and geochemistry of the Los Cuartos granite, Tafi del Valle, Tucuman, northwest of Argentina: its integration to the regional magmatic layout  

International Nuclear Information System (INIS)

Los Cuartos Granite crops out on the western flank of the Cumbres Calchaquies, east of Tafi del Valle, Tucuman Province, Argentina. It has a granitic to granodioritic composition, of two micas, being biotite dominant. The granite is medium grained and inequigranular, with rare K-feldspar megacrysts. It contains host-rock xenoliths with different degrees of assimilation. The granite intrusion produced contact metamorphism in the surrounding basement, with development of andalucite porphyroblasts and poikiloblastic biotite. The granite is calk-alkaline and peraluminous, and is K- and P-rich and Ca- and Napoor compared to other granitoids of the region. The pluton shows late-tectonic features with regard to the regional deformation. The granite possibly intruded during the Ordovician (Famatinian Cycle) and its emplacement was structurally controlled by the Tafi Megafracture. Los Cuartos Granite and other intrusive bodies of the region share similar petrographical, geochemical, structural and geochronological characteristics. (Author).

2010-01-01

57

Intrusion Detection Systems  

CERN Document Server

In our world of ever-increasing Internet connectivity, there is an on-going threat of intrusion, denial of service attacks, or countless other abuses of computer and network resources. In particular, these threats continue to persist due to the flaws of current commercial intrusion detection systems (IDSs). Intrusion Detection Systems is an edited volume by world class leaders in this field. This edited volume sheds new light on defense alert systems against computer and network intrusions. It also covers integrating intrusion alerts within security policy framework for intrusion response, rel

Pietro, Roberto Di

2008-01-01

58

Nuclide sorption on granite  

International Nuclear Information System (INIS)

Some equilibrium sorption experiments were made to evaluate surface and bulk reactions of granite. The nuclides examined are Cs and Np. The granite samples are sliced as thin as 0.7 to 1.3 mm and crushed samples (< 0.105 mm) are also used. The nuclide amount sorbed on granite of unit weight is dependent on the thickness of samples for both Cs and Np. The model that diffusion porosity decreases with the distance from the wall was proposed to explain these experimental results. Also, the error of measurements was examined. (author)

1984-01-01

59

Human intrusion: New ideas?  

International Nuclear Information System (INIS)

Inadvertent human intrusion has been an issue for the disposal of solid radioactive waste for many years. This paper discusses proposals for an approach for evaluating the radiological significance of human intrusion as put forward by ICRP with contribution from work at IAEA. The approach focuses on the consequences of the intrusion. Protective actions could, however, include steps to reduce the probability of human intrusion as well as the consequences. (author)

2002-06-01

60

SHRIMP zircon U-Pb dating of the mafic and felsic intrusive rocks of the Saza area in the Lupa goldfields, southwestern Tanzania: Implication for gold mineralization  

Directory of Open Access Journals (Sweden)

Full Text Available The Lupa Goldfield (LGF is one of the eight structural terranes in the NW – SE striking Ubendian Belt of SW Tanzania. The LGF is comprised of granitic gneisses with bands of amphibolites which are intruded by mafic intrusions including gabbros, granodiorites, diorites; and various granites as well as metavol-canics. These rocks are cross-cut by narrow mafic dykes and aplites. SHRIMP zircon U-Pb data are presented for the granodiorite and a mafic dyke that cross-cut the granodiorites in the Saza area of the LGF, with the aim of constraining the mafic and felsic magmatism and their implication to gold mineralization. The zircon U-Pb data shows that the Saza granodiorites were emplaced at 1924 ± 13 Ma (MSWD = 2.6 whereas the cross-cutting mafic dyke yielded a zircon U-Pb age of 1758 ± 33 Ma (MSWD = 0.88. The dated granodiorite sample was in sheared contact with an altered mafic intrusive rock, most likely a diorite, along which an auriferous quartz vein occurs. The 1924 ± 13 Ma age of granodiorites is within error of the reported molybdenite Re-Os age of 1937 Ma determined for the gold mineralization event in Lupa Goldfields. Although auriferous quartz veins are younger than the granodiorites, the more or less similar ages between the emplacement of granodiorites and the mineralizing event indicate that the granodiorites might be the heat source (or driver of hydrothermal fluids responsible for gold mineralization in the Lupa goldfields. This would further suggest that gold mineralization in the LGF is intrusion-related type. The mafic dykes represent the youngest rocks to have been emplaced in the area and hence the 1758 ± 33 Ma age of the mafic dykes conclude the magmatic evolution in the Lupa goldfields during the Palaeoproterozoic.

Shukrani Manya

2012-09-01

 
 
 
 
61

Lung Cancer in Younger Patients  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Carcinoma of the lung is rare in younger patients, but occasional reports of this condition have appeared in the literature. This article reviews the clinical and pathological patterns of bronchogenic carcinoma in 96 patients, 40 years old or younger seen at UCLA (University of California, Los Angeles) Hospital between 1956 and 1976. This review confirms the finding in other reports of a higher proportion of women among younger patients with lung cancer as well as a relatively low incidence o...

Ganz, Patricia A.; Vernon, Stephen E.; Preston, Dale; Coulson, Walter F.

1980-01-01

62

A-type granite and the Red Sea opening  

Science.gov (United States)

Miocene-Oligocene A-type granite intrudes the eastern side of the Red Sea margin within the zone of extension from Jiddah, Saudi Arabia south to Yemen. The intrusions developed in the early stages of continental extension as Arabia began to move slowly away from Africa (around 30-20 Ma). Within the narrow zone of extension silicic magmas formed dikes, sills, small plutons and extrusive equivalents. In the Jabal Tirf area of Saudi Arabia these rocks occur in an elongate zone consisting of late Precambrian basement to the east, which is gradually invaded by mafic dikes. The number of dikes increases westward until an igneous complex is produced parallel to the present Red Sea axis. The Jabal Tirf igneous complex consists of diabase and rhyolite-granophyre sills (20-24 Ma). Although these are intrusine intrusive rocks their textures indicate shallow depths of intrusion (< 1 km). To the south, in the Yemen, contemporaneous with alkali basaltic eruptions (26-30 Ma) and later silicic eruptions, small plutons, dikes, and stocks of alkali granite invaded thick (1500 m) volcanic series, at various levels and times. Erosion within the uplifted margin of Yemen suggests that the maximum depth of intrusion was less than 1-2 km. Granophyric intrusions (20-30 Ma) within mafic dike swarms similar to the Jabal Tirf complex are present along the western edge of the Yemen volcanic plateau, marking a north-south zone of continental extension. The alkali granites of Yemen consist primarily of perthitic feldspar and quartz with some minor alkali amphiboles and acmite. These granites represent water-poor, hypersolvus magmas generated from parent alkali basalt magmas. The granophyric, two-feldspar granites associated with the mafic dike swarms and layered gabbros formed by fractional crystallization from tholeiitic basalt parent developed in the early stages of extension. Initial 87Sr/86Sr ratios of these rocks and their bulk chemistry indicate that production of peralkaline and metaluminous granitic magmas involved both fractio??nation and partial melting as they ascended through the late Precambrian crust of the Arabian plate. ?? 1992.

Coleman, R. G.; DeBari, S.; Peterman, Z.

1992-01-01

63

Research on metallogenic specialization and metallogenic prognosis of granite in Nanling region: a case study of hydrothermal uranium deposit and hydrothermal tungsten-tin deposit  

International Nuclear Information System (INIS)

According to the principles of remote sensing information model and stepwise discriminant analysis, the metallogenic specialization discrimnant model of the intrusions rich in uranium and tungsten-tin was established, based on the data of 339 granite samples which consist of 99 granite samples rich in uranium, 89 granite samples rich in tungsten-tin and 151 granite under estimation in Nanling region. F test results showed that this model was applicable and highly significant for the intrusion estimation. The model was used to judge the uranium bearing or tungsten-tin bearing potential of the under estimated intrusions, and supplied a evidence for the further estimation of metallogenic intrusions. The built model has objectivity and operability, implements the quantitative evaluation for metallogenic specialization, and should play an important role on metallogenic specialization researches. (authors)

2010-11-01

64

Chemical characteristics of zircon from A-type granites and comparison to zircon of S-type granites  

Science.gov (United States)

The trace element content in zircons from A-type granites and rhyolites was investigated by using back-scattered electron images and electron microprobe analyses. The studied Proterozoic (Wiborg batholith, Finland and Pará, Amazonas and Goiás states, Brazil) and Variscan (Krušné Hory/Erzgebirge, Czech Republic and Germany) plutons cover a wide range of rocks, from large rapakivi-textured geochemically primitive plutons to small intrusions of F-, Li-, Sn-, Nb-, Ta-, and U-enriched rare-metal granites. While zircon is one of the first crystallized minerals in less fractionated metaluminous and peraluminous granites, it is a late-crystallized phase in peralkaline granites and in evolved granites that may crystallize during the whole process of magma solidification. The early crystals are included in mica, quartz, and feldspar; the late grains are included in fluorite or cryolite or are interstitial. The zircon in hornblende–biotite and biotite granites from the non-mineralized plutons is poor in minor and trace elements; the zircon in moderately fractionated granite varieties is slightly enriched in Hf, Th, U, Y, and HREEs; whereas the zircon in highly fractionated ore-bearing granites may be strongly enriched in Hf (up to 10 wt.% HfO2), Th (up to 10 wt.% ThO2), U (up to 10 wt.% UO2), Y (up to 12 wt.% Y2O3), Sc (up to 3 wt.% Sc2O3), Nb (up to 5 wt.% Nb2O5), Ta (up to 1 wt.% Ta2O5), W (up to 3 wt.% WO3), F (up to 2.5 wt.% F), P (up to 11 wt.% P2O5), and As (up to 1 wt.% As2O5). Metamictized zircons may also be enriched in Bi, Ca, Fe, and Al. The increase in the Hf content coupled with the decrease in the Zr/Hf value in zircon is one of the most reliable indicators of granitic magma evolution. In the zircon of A-type granites, the Zr/Hf value decreases from 41–67 (porphyritic granite) to 16–19 (equigranular granite) in the Kymi stock, Finland, and from 49–52 (biotite granite) to 18–36 (leucogranite) in the Pedra Branca pluton, Brazil. In the in situ strongly fractionated Cínovec cupola (Erzgebirge), the Zr/Hf value decreases from 33–51 in the protolithionite granite at a depth of 1255 m to 7.5–25 in the zinnwaldite granite at a depth of 40 m. At the scale of individual crystals, the Zr/Hf value decreases from 86 to 68 from the cores to the rims of the zircons from the Teplice rhyolite and from 64 to 33 in the zircons from the biotite granite at Krupka, Erzgebirge. The contents of Hf and U in zircon are dependent mainly on the degree of granite fractionation and the nature and volume of the volatile phases and are independent of the A- or S-character of the parental melt. The zircon Zr/Hf ratios 55 and 25 are proposed to approximately distinguish common, moderately evolved and highly evolved granites. Zircons from the moderately and highly evolved granites of A- and S-type can be discriminated on the basis of their HREE content and the U/Th ratios. Nb, Ta, and W are present in zircon from the highly evolved granites from all studied areas, while high As, Bi, and Sc contents are typical only for the Erzgebirge.

Breiter, Karel; Lamarão, Claudio Nery; Borges, Régis Munhoz Krás; Dall'Agnol, Roberto

2014-04-01

65

Hydrogen isotope ratios of biotite and hornblende from some granitic masses in the Abukuma Plateau, Japan  

International Nuclear Information System (INIS)

D/H ratios and X sub(Fe)(Fe/(Fe + Mg)) values of coexisting biotite and hornblende from ''older'' and ''younger'' granitic rocks in the northern Abukuma Plateau were measured. These data show that both granitic rocks are the typical equilibrium type of Kuroda et al. (1978). However, delta D is higher and X sub(Fe) is lower for ''older'' granitic rocks than for ''younger'' granitic rocks. This difference may depend on the silica content of the whole rocks; e.g., that of ''older'' rocks is lower than that of ''younger'' ones. delta D value of ''aqueous fluid'' in the magma of these rocks can be estimated to be -3.0 -- -3.4%, which is the same to that for the Cretaceous granitic rocks in the Kitakami mountainous district. Hornblende in the gabbroic rocks associated with these granitic rocks was also investigated and it can be considered that the hornblendes were equilibrated with the water of ''aqueous fluid'' of the granitic magma. On the other hand, the biotite-hornblende pairs from the Samegawa, Ishikawa and Miyamoto masses do not show the simple equilibrium type but the disequilibrium or complicated type. This may be related to older ages (Paleozoic time) and poly-cyclic activities in terms of hydrogen isotope exchange equilibrium in these masses. (author)

1980-01-01

66

Heater test 1, Climax Stock granite, Nevada  

International Nuclear Information System (INIS)

We conducted a series of in-situ tests in the Climax Stock, an intrusive granite formation at the Nevada Test Site, to validate the concept of housing a nuclear waste repository in granitic crystalline rock. The thermal properties of the granite were measured with resistance heaters and thermocouple frames that had been emplaced in drilled holes in the floor of a drift 420 m below the surface. Data analysis was performed primarily by comparing the measured and calculated temperature histories, varying conductivity and diffusivity in the calculations until reasonable agreement was achieved. The best-fit value for in-situ conductivity was approximately 3.1 W/m x K, and the deduced value for in-situ diffusivity was approximately 1.2 mm"2/s. Anisotropic effects in the thermal field were less than 10%. Permeability was determined by sealing off portions of the drilled holes, using inflatable rubber packers and an air-pressurization system. We then compared the resulting decay in pressure with analytic solutions of the pressure loss from a cylindrical source in an infinite isotropic medium, obtaining a permeability of approximately 1 nanodarcy (nD) at about 30"0C. As the temperature increased, the permeability decreased to about 0.2 nD at about 50"0C and became too small to measure (<0.02 nD) at higher temperatures. These tests provided new data on the in-situ properties of a granite typical of the Basin and Range province and significantly advanced our understanding of and ability to perform in-situ thermal and permeability measurements. This knowledge will be of considerable value for future spent-fuel tests

1984-01-01

67

Metasomatism of ferroan granites in the northern Aravalli orogen, NW India: geochemical and isotopic constraints, and its metallogenic significance  

Science.gov (United States)

The late Palaeoproterozoic (1.72-1.70 Ga) ferroan granites of the Khetri complex, northern Aravalli orogen, NW India, were extensively metasomatised ~900 Ma after their emplacement, at around 850-830 Ma by low-temperature (ca. 400 °C) meteoric fluids that attained metamorphic character after exchanging oxygen with the surrounding metamorphic rocks. Albitisation is the dominant metasomatic process that was accompanied by Mg and Ca metasomatism. A two-stage metasomatic model is applicable to all the altered ferroan intrusives. The stage I is represented by a metasomatic reaction interface that developed as a result of transformation of the original microcline-oligoclase (An12-14) granite to microcline-albite (An1-3) granite, and this stage is rarely preserved. In contrast, the stage II metasomatic reaction front, where the microcline-bearing albite granite has been transformed to microcline-free albite granite, is readily recognisable in the field and present in most of the intrusives. Some of them lack an obvious reaction interface due to the presence of stage II albite granites only. When studied in isolation, these intrusives were incorrectly classified and their tectonic setting was misinterpreted. Furthermore, our results show that the mafic mineralogy of metasomatised granites has a significant impact on the characterisation of such rocks in the magmatic classification and discrimination diagrams. Nevertheless, the stage I metasomatised granites can be appropriately characterised in these diagrams, whereas the characterisation of the stage II granites will lead to erroneous interpretations. The close spatial association of these high heat producing ferroan granites with iron oxide-copper-gold (IOCG), U and REE mineralisation in the region indicates a genetic link between the metasomatism and the mineralisation. World-class IOCG, U and REE deposits are associated with metasomatised ferroan granites, suggesting that such a relationship may act as a critical first-order exploration target for undiscovered mineral deposits.

Kaur, Parampreet; Chaudhri, Naveen; Hofmann, Albrecht W.; Raczek, Ingrid; Okrusch, Martin; Skora, Susanne; Koepke, Jürgen

2014-06-01

68

Interior intrusion detection systems  

International Nuclear Information System (INIS)

The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs

1991-01-01

69

Intrusion detection sensors  

International Nuclear Information System (INIS)

Intrusion detection sensors are an integral part of most physical security systems. Under the sponsorship of the U.S. Department of Energy, Office of Safeguards and Security, Sandia Laboratories has conducted a survey of available intrusion detection sensors and has tested a number of different sensors. An overview of these sensors is provided. This overview includes (1) the operating principles of each type of sensor, (2) unique sensor characteristics, (3) desired sensor improvements which must be considered in planning an intrusion detection system, and (4) the site characteristics which affect the performance of both exterior and interior sensors. Techniques which have been developed to evaluate various intrusion detection sensors are also discussed

1978-09-14

70

The assessment of human intrusion into underground repositories for radioactive waste Volume 2: Appendices  

International Nuclear Information System (INIS)

This report has been prepared with the primary objective of establishing a methodology for the assessment of human intrusion into deep underground repositories for radioactive wastes. The disposal concepts considered are those studied in the performance assessment studies Pagis and Pacoma, coordinated by the CEC. These comprise four types of host rock, namely: clay, granite, salt and the sub-seabed. Following a review of previous assessments of human intrusion, a list of relevant human activities is derived. This forms the basis for detailed characterization of groundwater abstraction and of exploitation of mineral and other resources. Approaches to assessment of intrusion are reviewed and consideration is given to the estimation of probabilities for specific types of intrusion events. Calculational schemes are derived for specific intrusion events and dosimetric factors are presented. A review is also presented of the capacity for reduction of the risks associated with intrusions. Finally, conclusions from the study are presented

1990-01-01

71

Angle closure in younger patients.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PURPOSE: Angle-closure glaucoma is rare in children and young adults. Only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients in our database aged 40 or younger with angle closure. METHODS: Our database was searched for patients with angle closure who were 40 years old or younger. Data recorded included age at initial consultation; age at the time of diagnosis; gender; results of slit-lamp examination, gonioscopy, and ultrasoun...

Chang, Brian M.; Liebmann, Jeffrey M.; Ritch, Robert

2002-01-01

72

PETROGRAFÍA, GEOQUÍMICA Y GEOCRONOLOGÍA DEL GRANITO DE PARGUAZA EN COLOMBIA / PETROGRAPHY, GEOCHEMISTRY AND GEOCHRONOLOGY OF PARGUAZA GRANITE IN COLOMBIA  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish El Granito de Parguaza aflora en el departamento de Vichada-(Colombia), hacia la margen del río Orinoco y es parte del gran batolito descrito en Venezuela como Granito del Parguaza. Este cuerpo en Colombia aflora como cerros aislados tipo inselberg y serranías de poca extensión con pendientes abrupt [...] as que sobresalen entre las extensas llanuras terciarias. Representa uno de los granitos anorogénicos aflorantes más grandes del mundo y puede ser distinguido como una de las unidades colombianas más antiguas (Mesoproterozoico) que no han sufrido deformación. Se caracteriza por presentar textura rapakivi tipo wiborgita y piterlita, su composición es granítica a granítica de feldespato alcalino. Además de las variaciones composicionales y texturales, se encuentran zonas de grano fino, diques pegmatíticos, aplíticos y venas de cuarzo. Geoquímicamente se clasifica como un granito tipo A, metaluminoso a peralcalino, formado en ambiente post-colisional a anorogénico. Nuevas mediciones de U/Pb con LA-ICP-MS en circones indican nuevas edades concordantes de 1.392 ± 5 Ma y 1.402 ± 2 Ma para las partes más distales, respectivamente, mucho más jóvenes que edades propuestas anteriormente en territorio venezolano 1.545 Ma, lo cual puede ser interpretado como un intrusivo más complejo o como procesos de cristalización muy lentos de núcleo a borde. Por otro lado, estas edades son correlacionadas con granitos anorogénicos similares en el W del Cratón Amazónico en Brasil y con otros afloramientos rapakivi estudiados en el departamento de Guainía al SE de Colombia. Abstract in english The Parguaza Granite outcrops in the Vichada department of Colombia, towards the Orinoco River margin, where it conforms a portion of the large batholith described in Venezuela as Granito de El Parguaza. This intrusion outcrops in Colombia as isolated inselberg hills and moderately extended mountain [...] chains with abrupt slopes that protrude through Tertiary plains. It represents one of largest anorogenic granites worldwide and is one of the oldest colombian units (Mesoproterozoic) without tectonic deformation. The granite exhibits both typical Wiborgite and Pyterlite rapakivi texture, with a monzogranitic to alkali feldspar granitic composition. Among the compositional and textural variations, we find fine-grain zones, pegmatitic and aplitic dikes as well as quartz veins. Geochemically, it conforms a metaluminous to peralkaline A-type granite, intruded under post-collisional to rifting anorogenic conditions. New U/Pb measurements with LA-ICP-MS in zircons show hither to unknown concordant ages of 1392 ± 5 My to 1402 ± 2 My, respectively in the more distal zones; much younger than 1545 My ages reported in Venezuela, which may be explained or by a more complex intrusion and crystallization history or by a very slow crystallization process from the core to the edge; on the other hand, these ages are in concordance to similar anorogenic granites from the W Amazonian Craton in Brazil and with other rapakivi outcrops studied in the Guainía Department in the south-east of Colombia.

Bonilla-Pérez, Amed; Frantz, José Carlos; Charão-Marques, Juliana; Cramer, Thomas; Franco-Victoria, José A.; Mulocher, Elise; Amaya-Perea, Zeze.

73

Sr-Nd isotope geology and tectonomagmatic setting of the Dehsalm intrusives (Lut Block, Eastern Iran)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Dehsalm porphyritic shallow intrusives belong to the Lut Block volcanic-plutonic belt (central eastern Iran). Previous research on alteration, mineralization and hydrothermal fluids indicates that a Cu-Mo porphyry type mineralization system is related with these intrusives (Arjmandzadeh et al., 2012). The rocks studied in this work range in composition from gabbro-diorite to granite, with dominance of monzonites and quartz monzonites, and have geochemical features of high-K calc alkaline ...

Arjmandzadeh, R.; Santos, J. F.; Ribeiro, S.

2013-01-01

74

The GRANIT spectrometer  

International Nuclear Information System (INIS)

The existence of quantum states of matter in a gravitational field was demonstrated recently in the Institut Laue-Langevin (ILL), Grenoble, in a series of experiments with ultra cold neutrons (UCN). UCN in low quantum states is an excellent probe for fundamental physics, in particular for constraining extra short-range forces; as well as a tool in quantum optics and surface physics. The GRANIT is a follow-up project based on a second-generation spectrometer with ultra-high energy resolution, permanently installed in ILL. It will become operational in 2011. The spectrometer consists of several neutron-optics elements and UCN detectors installed on a massive granite table in an aluminium vacuum chamber with a volume of about 1.5 m3. 3 types of detectors will be used at the first stage of the GRANIT experiment: 3He gaseous proportional counters with extremely low background, position-sensitive nuclear-track UCN detectors will be used to study the spatial distribution in quantum states, and real-time position-sensitive detectors with a resolution of a few hundred microns to measure velocity distributions of neutrons in quantum states. The key elements of the GRANIT spectrometer is a set of mirrors to shape/analyze neutron spectra and to store neutrons in quantum states

2010-10-01

75

Caracterización geoquímica del granito El Durazno, extremo norte de la sierra de Velasco, La Rioja / Geochemical characterization of El Durazno granite, Northern Sierrra de Velasco, La Rioja  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish El área de estudio se ubica en el norte de la sierra de Velasco, en la provincia de La Rioja. Está compuesta principalmente por rocas graníticas que cristalizaron durante dos eventos magmáticos principales en el Ordovícico y el Carbonífero. Los granitos más antiguos presentan diferentes grados de de [...] formación y los más jóvenes no están deformados. Los granitos datados como carboníferos hasta el presente en este sector son Asha y San Blas. Este último presenta una zona central más evolucionada químicamente, asociado a mineralizaciones de Sn. El granito El Durazno aflora al sureste del granito San Blas, no está deformado e intruye al ortogneis Antinaco, compuesto por rocas deformadas del Ordovícico. Es un granito postorogénico, peraluminoso y fuertemente diferenciado, con contenidos de Na2O>K2O. Presenta altos contenidos en Rb, Li, W, Cs, Nb y Ta y bajos en Ba, Sr, Y, Zr y Ce. El índice de caracterización geoquímica (GCI) para granitos asociados a mineralizaciones de W da valores positivos mayores que 4. Las tierras raras presentan contenidos totales bajos, entre 5,3 y 15,3 ppm, anomalía negativa de Eu y efecto tetrada convexo. En el borde norte del granito El Durazno existen vetas de cuarzo con wolframita y hematita distribuidas irregularmente que intruyen al ortogneis Antinaco. Tienen rumbo aproximado N-S y una corrida irregular. La ausencia de deformación, relaciones de campo y características geoquímicas indican que el granito El Durazno es un intrusivo muy diferenciado asociado a mineralización de W y de posible edad carbonífera. Abstract in english The studied area is located in the north of the sierra de Velasco, La Rioja province. It is mainly composed of granitic rocks that crystallized during two main magmatic events in the Ordovician and Carboniferous. The older granites have different types of deformation whereas the younger granites are [...] not deformed. Two Carboniferous granites have been dated in this area: Asha and San Blas. The latter has a chemically evolved central zone related to Sn mineralization. The El Durazno undeformed granite outcrops southeast of the San Blas granite, and intrudes into the deformed Ordovician Antinaco orthogneiss. It is a postorogenic, peraluminous and strongly differentiated granite, with contents of Na2O>K2O. It has high values of Rb, Li, W, Cs, Nb and Ta, and low values of Ba, Sr, Y, Zr and Ce. The geochemical characterization index (GCI) for W-bearing differentiated granites is positive with values greater than 4. The REE show low total contents, between 5,3 and 15,3 ppm, negative Eu anomalies and a convex tetrad effect. At the northern border of the El Durazno granite, quartz veins with irregularly distributed wolframite and hematite cross-cut the Antinaco orthogneiss. The veins have irregular north-south strike. The absence of deformation, field relations and geochemical characteristics indicate that the El Durazno granite is a highly differentiated intrusive associated with W mineralization and of possible Carboniferous age.

Báez, Miguel A; Fogliata, Ana S; Hagemann, Steffen; Sardi, Fernando G.

76

The Fanos granite: structure, emplacement and geodynamic significance (Eastern Axios/Vardar Zone, Northern Greece)  

Science.gov (United States)

The Fanos granite occurs in the Peonia Subzone of the Eastern Axios-Vardar Zone in Northern Greece. It is a Late Jurassic (158±1 Ma), N-S trending granite, intruding the Mesozoic back-arc Geuvgeuli ophiolitic complex (Peonia Subzone). It is composed of three main rock types namely aplitic granite, granite and microgranite evolved by fractional crystallization. At the eastern contact of the Fanos granite with the host ophiolitic rocks the initial intrusion character of the granitic bodies is well preserved. On the other hand, the western contact is overprinted by a few meters thick, westward-vergent semiductile thrust zone, probably of Late Jurassic-Early Cretaceous age. For the better understanding of the geotectonic evolution of the broader area, the Fanos granite is compared with the Mid-Late Jurassic Kastaneri volcano-sedimentary formation allocated on the eastern part of the Paikon Massif, on which the Guevgeuli ophiolites were obducted. In our study we address three major topics: a) the origin of the Fanos granite, b) the geochemical correlation between Fanos granite and Kastaneri formation and c) the relationship of the granite with the remnants of an oceanic island-arc or an active continental margin geotectonic setting situated in the Neotethys (=Axios/Vardar ocean). The collected rock samples are granites, aplitic granites, microgranites, rhyolites, quartz diorites, migmatites and amphibolites. These samples were analysed by X-ray fluorence for major and trace elements. The granite shows peraluminous characteristics, high-K calc-alkaline affinities and I-type features. The Sr initial isotopic ratios of the granite range between 0.70519 and 0.70559, while the Nd initial isotopic ratios range between 0.51236 and 0.51239, reflecting EM-I (Enriched Mantle-I) component. The trace element patterns along with the isotopic composition of the rocks indicate absence of continental crustal material contamination. Moreover, the geochemical data imply a common origin between the Fanos granite and the Kastaneri formation. Taking into account our structural and geochemical data along with the existing isotopic and geotectonic data of the broader Axios/Vardar Zone, we suggest that the studied granitic rocks were formed during an intraoceanic-subduction within the Neotethys ocean, approximately at the same time with the amphibolite sole formation, rather than during the evolution of an active continental margin. In the Late Jurassic, a general westward ophiolite obduction on the Pelagonian continental margin, resulted to the thrusting of the Fanos granite together with the obducted ophiolites.

Michail, Maria; Kilias, Adamantios; Koroneos, Antonios; Ntaflos, Theodoros; Pipera, Kyriaki

2014-05-01

77

Geochronologic and Sr-isotopic studies of certain units in the Barberton granite-greenstone terrane, Swaziland  

International Nuclear Information System (INIS)

Rb-Sr whole rock and mineral isotopic analyses of granitoid units in Swaziland have yielded the following ages: A. Granodiorite Suite - 3 350 plus minus 57 Ma; B. Mponono Intrusive Suite - approximately 2 100 Ma; C. Sphene-bearing Orthogneiss - 2 734 plus minus 266 Ma; D. Ngwempisi Granite - 2 802 plus minus 56 Ma; E. Sinceni Granite - approximately 2 800 Ma; F. Kwetta Granite - 2 520 plus minus 422 Ma; G. Mhlosheni Granite - approximately 2 290 Ma; H. Hlatikulu Granite - approximately 2 420 Ma; I. Nhlangano Gneiss - approximately 2 240 Ma. Of these ages, only those from the Granodiorite Suite, sphene-bearing orthogneiss and Kwetta Granite are defined by whole rock isochrons. The age for the Ngwempisi Granite is a biotite-whole rock age. The other ages are defined by whole rock errorchrons and are believed to reflect times of imperfect Sr isotopic homogenization in magmas or during metamorphism. The ages of the Granodiorite Suite, sphene-bearing orthogneiss and Ngwempisi, Sinceni, Kwetta, Mhlosheni and Hlatikulu granites are believed to reflect times of emplacement. The ages of the Mponono Intrusive Suite and Nhlangano Gneiss are believed to reflect metamorphism. As such, these age data suggest that a major, previously unrecognized, tectonic event (or events) affected the Precambrian rocks in southern Swaziland between about 2 500 Ma and about 2 100 Ma ago. The full significance of this event has yet to be evaluated

1983-01-01

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The missing link between granites and granitic pegmatites  

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Full Text Available In this contribution we provide evidence for the extraction of volatile and incompatible element enriched melts from common granites. This provides a mechanism showing that at least a large proportion of granitic pegmatites could be genetically directly connected to a main granite body. In granites there are often two principal types of melt inclusions: (i those that represent the bulk chemistry of the granite and (ii those with very different compositions. In the Variscan Erzgebirge granites, the second type is characterized by the abundance of fluorine. However, in other geodynamic settings inclusions in granites can contain high concentrations of other elements which may take over the function of fluorine. From textural relationships the second inclusion type represents intergranular melts enriched in all elements incompatible with the ideal haplogranite system. Due to the high volatile content of such melts, the viscosity can be several orders of magnitude lower than the quasi-solid bulk system and can therefore move rapidly through the partially or totally crystallized host, and flow together into a separate system forming pegmatite bodies inside or outside the granite body. Another important effect of the high volatile content is the phase separation resulting from the speciation changes OH- ? H2O or CO32- ? CO2 due to temperature and/or pressure changes at different locations within the granite-intergranular melt system. Since melt inclusions provide a means of conserving original un-degassed compositions, they provide important evidence for closing the gap between granites and granitic pegmatites.The paper is dedicated to two Czech colleagues - Petr ?erný and Milan Novák - who have devoted their lives to the study of granitic pegmatites.

Thomas R

2013-07-01

79

Magnetic fabric and emplacement mechanisms in a co-mingled mafic and felsic magma chamber: the Espinharas granite (Borborema Province, NE Brasil)  

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The Espinharas granite is a co-mingled mafic and felsic magmatic complex forming part of the widespread Brasiliano plutonism that affected the Borborema Province during the Neoproterozoic. Syenogranite is mixed and mingled with diorite generating a range of aluminous shoshonitic hybrid rocks containing mafic microgranular enclaves (MME) of various shapes and orientations. Geochemical modelling shows that the pluton originated by upper-mantle magma underplating and fault-assisted intrusion of diorite, which would supply heat for partial melting of the crust and formation of syenogranite. The Espinharas granite comprises syenogranites and diorites associated with quartz-monzonites, monzodiorites and syenites mainly deformed in the magmatic state. The pluton is emplaced within Paleoproterozoic augen gneisses from the basement and is bounded by high-temperature NE-trending mylonitic shear zones at its western and eastern borders. To the south, the pluton is in contact with the E-trending high-grade transpressional Patos shear zone. Magmatic foliations can be observed throughout the syenogranite and in the felsic rocks, being defined by a SPO of feldspars and quartz. However, they appear to be absent in the diorite. The microgranular enclaves display irregular contacts with the host syenogranite and may be often aligned in agreement with the magmatic foliation; they are also randomly dispersed and disrupted by monzo- to syenogranitic veins. The Anisotropy of Magnetic Susceptibility (AMS) technique was employed in order to investigate the mechanical relationships between mingled mafic and felsic magmas, as well as their emplacement mechanisms. Susceptibilities are usually high (k > 1.3 mSI), suggesting that Ti-magnetite is the main carrier of the magnetic signal. The magnetic lineation plunges shallowly to NE, parallel to the pluton main elongation axis. Zircons from diorite and syenogranite yield U-Pb (SHRIMP) ages of ~ 620 Ma, which are attributed to the crystallization of the granite and are younger than the main metamorphic event in the Seridó Belt (~ 575 Ma). These data suggest that the magnetic fabric of the Espinharas granite records the high-temperature deformation observed in the Seridó Belt. This deformation was active during a prolonged time range (~ 100 Ma) in a hybrid magmatic chamber emplaced in the middle- to shallow continental crust. These conditions indicate that the Patos shear zone controlled the development of the magmatic- to solid-state fabric of the Espinharas granite, highlighting the contribution of strain partitioning in the mechanical mingling of magmas in the continental crust.

Viegas, G.; Gouveia, F.; Archanjo, C.; Hollanda, M.

2013-12-01

80

Rb-Sr and K-Ar geochronology and petrogenesis of the Aji Granite in the eastern Sanuki district, Ryoke Belt, southwest Japan  

International Nuclear Information System (INIS)

The Rb-Sr and K-Ar geochronological study was made for the Aji Granite in the eastern Sanuki district, one of the fine-grained granites in the Ryoke Belt. This granite is divided into hornblende-free and hornblende-bearing facies. The former gives a Rb-Sr whole-rock isochron age of 82.9±8.0 Ma with SrI of 0.70773±0.00007 which is interpreted as the intrusive age of the Aji Granite and therefore the final plutonism in the eastern Sanuki district. Biotites separated from six samples give K-Ar biotite ages between 80.4 Ma and 79.4 Ma. K-Ar hornblende age is of 83.5 Ma. These age data suggest rapid cooling after the emplacement of the granite. The initial Sr and Nd ratios of the Aji Granite fall within the range of the Ryoke granitoids. They are close to those of the Fine-grained in the Awaji Island, but differ from those of the Busetsu, Kadoshima and Otagiri Granites in the Chubu district. The Aji Granite and Fine-grained Granite in the Awaji Island have I-type granite chemical characteristics, whereas other fine-grained granites in the Ryoke Belt have S-type characteristics. This suggests varying source characteristics for the fine-grained granitic magmas in the Ryoke Belt. (author)

2003-02-01

 
 
 
 
81

Geochronology and geochemistry of Hamaerwula granitic porphyry in Inner Mongolia of China  

Science.gov (United States)

Hamaerwula granitic porphyry is located in the active continental margin of the Late Paleozoic at the southeastern edge of Erguna-Xingan blocks,and also lies in the middle parts of Tongxing-Baoshi volcanic rock zone within the Daxinganling volcanic rock belts of the Mesozoic. Daxinganling is the major tectonic-magmatic activity belts in the eastern China.. The Hamaerwula granitic porphyry is exposed in approximately 33.29 km2, which occurred as a intrusion in the late Jurassic volcanic - sedimentary strata, indicating that the intrusion was formed after the Late Jurassic. U-Pb isochron determination shows that the weighted average of the apparent ages of the granitic porphyry is 124.9±2.5Ma.The granitic porphyry geochemisty is characterized by high SiO2(with a mean value of 74.48% ranging 71.262%-77.61%) , rich alkali (K2O+Na2O)( with mean value of 7.46% ranging 6.32%-8.77%) , and high K2O/Na2O ratio (1.1-2.2). The granitic porphyry is rich in Al, and poor in Ca,Fe,and Mg, belonging to potassium-rich calc-alkaline rock series. Sr,Rb,Th and Ce are enriched, and Zr, Hf, Sm, Y and Yb are relatively depleted. The chondrite-normalized patterns of rare earth elements(REE) show that light REE are concentrated and well fractionated, heavy REE are relative deficient and poorly fractionated, and negative Eu anomaly is highly strong. The tectonic settings discrimination analysis of the granitic porphyry with REE and trace elements suggested that the granitic porphyry is of the late orogenic granite porphyry. The orogenesis in Daxinganling area had been finished before Mesozoic, the continental volcanic-sedimentary strata were developed in Mesozoic, the magmatic activity was abnormally strong in Mid- and late Mesozoic.The field geological features showed that the granitic porphyry in this area was formed in the late orogenic period. A large number of studies confirmed that K-rich calc-alkaline granites were formed in tensional tectonic environment. Geochronology and geochemistry characteristics show that (1)the granite porphyry in Hamaerwula was formed in the early Cretaceous(K1),the zircon U-Pb age was 124.9 ± 2.5Ma;(2) SiO2 in Hamaerwula granitic porphyry was saturated,and aluminum supersaturated;(3) the Hamaerwula granitic porphyry belonged to the late orogenic granitoids.

Xu, X.; Zhao, Q.; Zheng, C.; Sinoprobe Program of China

2011-12-01

82

Long-lived Paleoproterozoic granitic magmatism in the Seridó-Jaguaribe domain, Borborema Province-NE Brazil  

Science.gov (United States)

The northeastern part of the Borborema Province is dominated by Paleoproterozoic migmatitic tonalitic to granitic orthogneisses (Caicó Complex) that are the basement for younger, metavolcanosedimentary rock assemblages. Within this complex gneissified, porphyritic metagranitoid rocks (the G2-type augen gneisses) are fairly common and supposed to define a synorogenic magmatism at c. 2.0 Ga. New U-Pb (SHRIMP) on zircons and Sm-Nd data shows that these augen gneisses do not differ significantly from the metaplutonic rocks of the basement complex regarding their nature and emplacement age of the primary magmas. U-Pb ages cluster in a time interval between 2.17 and 2.25 Ga and are correlated with Nd parameters (older tDM model ages and negative initial ?Nd values) indicating an origin from recycling of an older, probably Neoarchean crust. The regional host rocks that accommodate the augen gneiss could be c. 2.4-2.3 Ga supracrustal sequences presently preserved as small remnants in the Caicó Complex. The Paleoproterozoic magmatic activity extends to the Late Paleoproterozoic with the intrusion of the Serra Negra pluton (now a coarse augen gneiss) which yielded a (semi) concordant U-Pb age of c. 1.75 Ga. This magmatic activity, until now unsuspected in the Caicó Complex, was probably related to crustal extension and rifting over large areas that include the NE Brazil and the Nigerian shield in Africa.

Hollanda, Maria Helena B. M.; Archanjo, Carlos J.; Souza, Laécio C.; Dunyi, Liu; Armstrong, Richard

2011-12-01

83

Uranium distribution in the Um Samra-Um Bakra granitic plutons and associated pegmatites, Central Eastern Desert, Egypt  

International Nuclear Information System (INIS)

Um Samra -Um Bakra granitic plutons are located in the central Eastern Desert between latitudes 25 degree 15 and 25 degree 19 N and longitudes 34 degree 03 and 34 deg 11 E. The younger granites in the studied area are subdivided into two varieties, monzogranites and syenogranites. The syenogranites could be considered as uraniferous (fertile) granites, originated from highly fractionated, U-rich magma. They contain from 15.5 to 24.5 ppm uranium and from 20.5 to 25.0 ppm thorium. Both U and Th were essentially concentrated during the magmatic stage in accessory minerals as apatite, fluorite and zircon. The secondary processes as fracturing and alteration processes allowed the meteoric water and hydrothermal solutions to liberate labile uranium and redeposited their loads along micro fractures. Pegmatites show higher U-contents relative to both types of the studied younger granites. Pegmatites could be classified into two separate groups: 1) mineralized pegmatites which are located near the contact of Um Samra younger granites; they possess U-mineralization (kasolite) and 2) non-mineralized pegmatites which are distributed within Um Bakra younger granites themselves; they show lower U-contents relative to the first type. (author)

2004-12-04

84

Contribution to the uranium geochemistry on granites in Ecuador  

International Nuclear Information System (INIS)

This work aims to define the position of two of Ecuador granitic deposits within the field of the geochemistry of granites in general and of the geochemistry of uranium in particular. The regions concerned are: The Bonita and ABITAGUA. For each range the petrochemical framework is first of all determined and then the degree of chemical homogeneity of rocks is evaluated. In the petrochemical groups thus obtained the geochemical behaviour of the uranium is studied. From the viewpoint of the geochemistry of the granites under investigation, a comparison of the laws of distribution of the mayor elements in two ranges shows up a covergence of average composition which was not anticipated by geological and petrografic considerations alone. The statistical and geochemical distribution laws of the total uranium as a function of petrochemical variations are established. A study of chemical forms of uranium in the rocks has drawn an attention to the qualitative and quantitative importance of the faction of uranium soluble in delute acids. We have therefore reconsidered on the one hand, the laws of distribution of the insoluble and we have justified on the other hand the interest presented by the soluble post magmatic phenomena which makes possible to find a genetic connection between the uraniferous deposits and the intrusive massifs. Finally we have given tables of analytic composition total of the granites. (Author)

1995-01-01

85

The GRANIT spectrometer  

International Nuclear Information System (INIS)

The existence of quantum states of matter in a gravitational field was demonstrated recently in the Institut Laue-Langevin (ILL), Grenoble, in a series of experiments with ultra cold neutrons (UCN). UCN in low quantum states is an excellent probe for fundamental physics, in particular for constraining extra short-range forces; as well as a tool in quantum optics and surface physics. The GRANIT is a follow-up project based on a second-generation spectrometer with ultra-high energy resolution, permanently installed in ILL. It has been constructed in framework of an ANR grant; and will become operational in 2011.

2011-10-01

86

The U-fertility criteria applied to the El Sela granite, Eastern Desert, Egypt  

International Nuclear Information System (INIS)

El Sela area is located in the southern Eastern Desert of Egypt, between Latitudes 22 deg. 13' and 22. deg 19' N and Longitudes 36 deg. 11' and 36 deg. 15' E, about 30 km south west of Abu Ramad City. It occupies about 73.5 km2. For a long time the granite massifs have been considered as resulting from the diapiric emplacement of large magma bodies. Recent studies increasingly show that most granite plutons in fact results from successive accretion of multiple injections of highly variable sizes, not always co-genetic and with highly variable metallogenic potential. Such a conception has very important consequences in exploration because the mineralization may be genetically related only to specific magma intrusion within the large granite complex as shown in Kab Amiri granite central Eastern Desert of Egypt for episyenites and in the Saint Sylvestre granite in the French Massif Central for vein type uranium mineralization. Therefore, detailed mapping and characterization of the different granite phases is decisive to define the most fertile parts of granite plutons for the occurrence of mineralization on which the exploration has to be focused. Such a concept is particularly applicable in the granite plutons of the Eastern Desert of Egypt where outcropping conditions are excellent. The fertility of a granitic pluton is mostly related to the extent of the overlap between the magmatic uranium enrichment, hydrothermal reworking through open fracture system and the existence of a suitable reservoir for the leached metals and followed eventually by a supergene enrichment phase. The northern part of El Sela granite complex was identified as the most fertile part where many granite intrusions are crosscut by long and wide shear zones associated with a series of alteration processes. The studied example is the ENE-WSW shear zone located in the northern part of El Sela granite pluton. The uranium mineralizations are the result of a succession of reactions between the rocks or minerals and the fluids. Hence, we have carried out detailed geologic and tectonic mapping coupled with laboratory mineralogical and geochemical studies. Field observations has shown that Gabal El Sela granites are highly weathered, cavernous and exposed as low to moderately separated hills which forms the remnants of a circular shaped granite pluton composed of at least two main different granite intrusions. The detailed geological and tectonic studies have shown that El Sela area was affected by at least nine successive tectonic events. These events are reflected by the high fracture intensity and consequently the intense weathering of the granite. It was proposed that the complex magmatic and tectonic history of the northern part of the El Sela granitic complex is highly fertile and represent a promising target for the occurrence of uranium ore deposits which are must be tested by a drilling program to complete the geophysical subsurface studies

2005-06-20

87

U-Pb ages and Nd isotope characteristics of the lateorogenic, migmatizing microcline granites in southwestern Finland  

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Full Text Available U-Pb ages and whole-rock Nd isotope data have been obtained from the Paleoproterozoic lateorogenic migmatizing microcline granites of southwestern Finland. Isotope dilution and ion microprobe U-Pb data on zircons and monazites show that the age spectrum of these granites is at least 1.85-1.82 Ga. Commonly, zircons and monazites record the same ages. The age variation in the Veikkola granite area is of the order of 25 Ma and indicates that this seemingly homogeneous granite consists of two separate intrusions. The zircons of the lateorogenic granites are pervasively altered and conventional U-Pb results are commonly discordant. The ion microprobe studies reveal that the granites contain very few inherited zircons with preserved original U-Pb isotope ratios, with the exception of the Oripää granite. Initial ?Nd values, mostly in the range of ?0.5 to ?1.0, imply a moderate input of older crustal material into most of the lateorogenic granites. A shift from more juvenile to less radiogenic Nd isotope composition is observed from north to south, and the variation pattern of ?Nd values of the lateorogenic granites is thus similar to that of the surrounding synorogenic granitoid rocks.

Matti Kurhila

2005-01-01

88

Identifying granite sources by SHRIMP U-Pb zircon geochronology: an application to the Lachlan foldbelt  

Science.gov (United States)

The potential genetic link between granites and their host sediments can be assessed using zircon age inheritance patterns. In the Lachlan fold belt, southeastern Australia, granites and associated high-grade metasedimentary rocks intrude low-grade Ordovician country rock. This relationship is well-exposed in the Tallangatta region, northeast Victoria (part of the Wagga-Omeo Metamorphic Complex). In this region granites (two I-types and two S-types) have intruded during the mid-late Silurian between approximately 410-430 Ma based on the ages of magmatic zircons. The age spectra for inherited zircons from the granites have been compared with those of detrital zircons from the enclosing low- and high-grade metasediments. In broad terms, both for detrital zircons in all four sediments and for inherited zircons in three of the four granites, the dominant ages are early Paleozoic and Late Precambrian, with sporadic older Precambrian ages extending up to 3.5 Ga. The ages of the youngest detrital zircons from the low-grade Lockhart and Talgarno terranes limit the time of sedimentation to ca. 466 Ma or younger. The youngest detrital zircons from two samples of the high-grade Gundowring terrane are 473 Ma, making these sediments Ordovician or younger, not Cambrian as originally suggested. However, the individual age spectra for the four selected metasediments are not well matched when closely examined. The age spectra of the inherited zircons in the granites also do not adequately match those in any of the metasediments. Thus, the metasediments might not be representative of the actual source rocks of the granites. While the exact source of the granites cannot be identified from the analysed samples, the existence of a large population of ca. 495 Ma inherited zircon grains in the S-type granites requires that the granite source contains a significant proportion of Cambrian or younger material. This does not preclude the existence of a Precambrian basement to the Lachlan fold belt but indicates that at the level of S-type magma generation, a Cambrian and/or younger protolith is required.

Keay, Sue; Steele, David; Compston, William

1999-12-01

89

Autonomic Intrusion Response System  

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Full Text Available Intrusion Response Systems (IRS counter attacks the attempts to compromise the integrity, confidentiality or availability of a resource. Most of the IRS requires human intervention to perform their response activities, which is time consuming, whereas, Autonomic Intrusion Response Systems (AIRS are self-healing systems inheriting their behavior from the natural immune system. Such self-healing autonomic systems are required to safeguard the network and resources and also to provide consistent service with high quality. This paper presents the state of the art of some existing intrusion response systems along with their comparative study. It also proposes a high level architectural organization and the essential features for an ideal AIRS. It also spotlights the application of autonomic response system in agriculture –SMARTAGRI.

G.Yamini

2011-02-01

90

The Torres del Paine intrusion as a model for a shallow magma chamber  

Science.gov (United States)

The shallow magmatic Torres del Paine Intrusive Complex (TPIC) belongs to a series of sub-volcanic and plutonic igneous bodies in Southern Chile and Argentina. This trench-parallel belt is located in a transitional position between the Patagonia Batholith in the West, and the alkaline Cenozoic plateau lavas in the East. While volumetrically small amounts of magmatism started around 28 my ago in the Torres del Paine area, and a second period occurred between 17-16 Ma, it peaked with the TPIC 12.59-12.43 Ma ago. The spectacular cliffs of the Torres del Paine National park provide a unique opportunity to study the evolution of a very shallow magma chamber and the interaction with its host rocks. Intrusion depth can be estimated based on contact metamorphic assemblages and granite solidus thermobarometry to 750±250 bars, corresponding to an intrusion depth of ca. 3km, ca. 500m above the base of the intrusion. Hornblende thermobarometry in mafic rocks agrees well with these estimates (Leuthold et al., 2014). The TPIC is composed of a granitic laccolith emplaced over 90ka (Michel et al., 2008) in 3 major, several 100m thick sheets, forming an overall thickness of nearly 2 km. Contacts are sharp between sheets, with the oldest sheet on the top and the youngest on the bottom (Michel et al., 2008). The granitic laccolith is under-plated by a ca. 400m thick mafic laccolith, built up over ca. 50ka (Leuthold et al. 2012), constructed from the bottom up. Granitic and mafic sheets are themselves composed of multiple metric to decametric pulses, mostly with ductile contacts between them, resulting in outcrop patterns resembling braided stream sediments. The contact of the TPIC with the Cretaceous flysch sediments document intrusion mechanism. Pre-existing sub-horizontal fold axes are rotated in the roof of the TPIC, clearly demonstrating ballooning of the roof; no ballooning was observed in the footwall of the intrusion. Extension during ballooning of the roof is indicated by dykes emanating from the roof of the intrusion into the host rocks. The dykes are perpendicular to the contact, radially shooting into the country rocks. Since the oldest granite is found in the roof, it is also permeated by dykes of successive intrusions. Contact metamorphism can be used to constrain the granite intrusion temperature to ca. 1000°C. Intrusion occurred in multiple pulses along the granite-host rock contact, in rapid succession, before significant cooling occurred in the aureole. Hydration of the biotite and feldspar of the immature sediments in the outer aureole contributed significantly to the overall thermal signature of the host-rock-TPIC system. In contrast, stable isotopes do not document significant fluid circulation. Leuthold, J., Müntener, O., Baumgartner, L., Putlitz, B., Ovtcharova, M., Schaltegger, U. (2012) Time resolved construction of a granitic to mafic laccolith (Torres del Paine, Patagonia). Earth Plan Sci Lett. 325. 85-92 Leuthold J., Müntener O., Baumgartner L.P., Putlitz B., (2014) Recycling of mafic crystal mush, transport and emplacement in the Torres del Paine mafic complex (Patagonia). J. Petrology; accepted pending revision Michel, J., Baumgartner, L.P. Putlitz, B., Ovtcharova, M., Schaltegger, U. (2008) Incremental growth of a shallow crustal laccolith over 80 kyrs: the Torres del Paine Granite, Patagonia. Geology vol. 36, 459-462

Baumgartner, Lukas; Bodner, Robert; Leuthold, Julien; Muntener, Othmar; Putlitz, Benita; Vennemann, Torsten

2014-05-01

91

Geochemistry of pegmatites associated with the Cape Coast granite complex of southern Ghana  

International Nuclear Information System (INIS)

The Cape Coast granite complex, which is associated with the metasedimentary basin rocks of Birimian in Ghana are, also referred to as the basin - type granitoids, and forms part of the two major types of Eburan granitoids in Ghana. The Cape Coast granite complex is characterized by various intrusions such as acid intrusion and pegmatites. The pegmatites associated with the Cape Coast granite complex are noted to be related to the margin of the granite batholiths. The mineralogical characteristics of the pegmatites have been documented, but there is little published information on the geochemical characteristics, source and tectonic settings and mode of emplacement of these pegmatites as compared to the Cape Coast granite complex. The objectives of this project were therefore to determine the compositions and geochemistry of the pegmatite and use the data to infer the possible source of these pegmatites. The geochemical data indicates that the pegmatites of the Egyaa, Saltpond and Akim Oda areas consist of a low to high-K, S-type characteristics, with three samples from Saltpond having metaluminous character. Lower values of molar CaO/ (MgO + FeOtot) coupled with higher values of molar Al2O3/ MgO + Fetot) suggest their derivation from partial melting from metabalistic source. The data suggests the rocks so have emplaced in a volcanic arc and ocean ridge geotectonic environment. (au)

2010-01-01

92

New U/Pb ages from granite and granite gneiss in the Ruby geanticline and southern Brooks Range, Alaska ( USA).  

Science.gov (United States)

New U/Pb zircon ages from the Ray Mountains of central Alaska clarify the plutonic history of the Ruby geanticline and support earlier suggestions that the Ruby geanticline and S Brooks Range were once parts of the same tectonostratigraphic terrane. U/Pb zircon ages of 109 to 112 Ma from the Ray Mountains pluton confirm previously reported mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid-Cretaceous K/Ar ages and rule out the possibility that the earliest intrusive phase of the pluton is older than mid- Cretaceous. New U/Pb zircon ages from 4 granite gneiss samples in the Ray Mountains indicate a Devonian protolith age of 390+ or -12 Ma and suggest that the Ruby geanticline, like the S Brooks Range, underwent a major plutonic event in mid-Paleozoic time.-Authors

Patton, Jr, W. W.; Stern, T. W.; Arth, J. G.; Carlson, C.

1987-01-01

93

Li in minerals from the Ilimaussaq alkaline intrusion, South Greenland  

International Nuclear Information System (INIS)

Li was analysed by instrumental neutron activation analysis and Cerenkov counting in 120 mineral samples (30 species) from the Ilimaussaq alkaline intrusion, South Greenland. More than 0.23 wt.% Li (0.5 wt.% Li_2O) is found in polylitionite, meptunite, riebeckite, Na-cookeite, ephesite, arfvedsonite, gerasimovskite and astrophyllite. Arfvedsonite (200-2500 ppm Li) carreis the bulk of Li in most of the highly alkaline rocks. Li-Mg and Li-F relations indicate that the distribution of Li is controlled by the structure of minerals, their absolute contents of Mg and F and the fractionation stage within the intrusion. Li is probably linked with F in the fluid state and this linkage continues into crystallising phases where Li occupies sites which also accommodate Mg. Li/Mg and LI/F ratios of Ilimaussaq rocks and minerals are higher than in equivalent materials from the Lovozero intrusion (Kola, Russia). The Li-Mg-Fe"2"+ geochemical association at Ilimaussaq (Fe"2"+>>Mg) and Lovozero (Fe"2"+mG) contrasts with the commercially important Li-rich but Mg-Fe"2"+-poor association found in certain granite pegmatites and greisenised granites. (au) (43 refs.)

1993-12-01

94

Petrology and geochemistry of the Los Cuartos granite, Tafi del Valle, Tucuman, northwest of Argentina: its integration to the regional magmatic layout; Petrologia y geoquimica del granito Los Cuartos, Tafi del Valle, Tucuman, noroeste de Argentina: integracion al esquema magmatico regional  

Energy Technology Data Exchange (ETDEWEB)

Los Cuartos Granite crops out on the western flank of the Cumbres Calchaquies, east of Tafi del Valle, Tucuman Province, Argentina. It has a granitic to granodioritic composition, of two micas, being biotite dominant. The granite is medium grained and inequigranular, with rare K-feldspar megacrysts. It contains host-rock xenoliths with different degrees of assimilation. The granite intrusion produced contact metamorphism in the surrounding basement, with development of andalucite porphyroblasts and poikiloblastic biotite. The granite is calk-alkaline and peraluminous, and is K- and P-rich and Ca- and Napoor compared to other granitoids of the region. The pluton shows late-tectonic features with regard to the regional deformation. The granite possibly intruded during the Ordovician (Famatinian Cycle) and its emplacement was structurally controlled by the Tafi Megafracture. Los Cuartos Granite and other intrusive bodies of the region share similar petrographical, geochemical, structural and geochronological characteristics. (Author).

Lopez, J.P.; Bellos, L.I.

2010-07-01

95

Petrology and petrogenesis of the older and younger granitoids of Wadi Beizah area, Central Eastern Desert, Egypt  

Science.gov (United States)

The studied granitoids of Wadi Beizah area, Central Eastern Desert, Egypt, are represented by older arc-granitoids intruded by a post-collisional stock of younger pink granite. The arc-granitoids (I-type) cover a wide compositional spectrum from meladiorites, diorites, quartzdiorites/monzodiorites and tonalites, to leucogranodiorites. Their distribution pattern is unimodal dominated by diorites. They are of low-K calc-alkaline character and represent the plutonic rocks of the mature, ensimatic island arc stage. Three models for the geotectonic environment of the younger granites of the Eastern Desert of Egypt have been suggested: (1) Within-plate, rifting, tensional environment similar to the Oslo Rift of Norway (Greenberg, 1981) Stern et al., 1984, 1986), (2) Extensive crustal anatexis during collisional tectonics, compression, thickening of the crust and thrust imbrication (Hussein et al., 1982; Ragab, 1987b), (3) Active continental margin geotectonic environment (Abdel-Rahman and Martin, 1987). These three models are discussed in detail. The present workers believe that the Younger Granites in general are the products of extensive crustal anatexis at the culmination of the Pan-African orogenic cycle when arc-arc suturing is complete. Recent studies revealed a low-angle thrust event in the Central Eastern Desert followed the initial arc-arc collision and continued after the deposition of the molasse-type sediments (Ries et al., 1983; El-Ramly et al., 1984; Greiling et al., 1984; Habib et al., 1985; Greiling and El-Ramly, 1985) which indicate thickening of the crust and compression regime at the time of emplacement of the Younger Granites. The dominance of ?granite minimum? composition of these late orogenic granites suggests extensive crustal anatexis. Their low Nb-content (< 40 ppm) precludes within-plate hot-spot related magma, in comparison with: (1) The post-Pan-African (400-100 M.a.) granitic rocks from the NE Sudan which on a geochemical evidence are the products of within-continental plate ?hot-spot? magmatism with Nb-content of about 50-300 ppm (Gass, 1979); (2) The Oslo Rift within-plate granites with Nb-content of 226 ppm (Pearce et al., 1984). A post-collision model showing the formation of the ?petrotectonic assemblage? of this stage (molasse-type sediments deposited in fault-bounded troughs, and calc-alkaline bimodal intermediate and felsic magmas) as well as the heat sources in the geotectonic environment of thrust imbrication and the mode of formation of the Younger Granites by crustal anatexis is suggested. K/Ar dating of a younger granite sample gave an age of 584 ± 5 M.a. which is compatible with several similar ages of younger pink granites in the Eastern Desert of Egypt. An older granite sample gave an age of 591 ± 7 M.a. (K/Ar method) indicating resetting of its isotopic clocks probably as a result of the extensive crustal anatexis event.

Ragab, A. I.; Menesy, M. Y.; Diab, M. M.

96

Artificial weathering of granite  

Directory of Open Access Journals (Sweden)

Full Text Available This article summarizes a series of artificial weathering tests run on granite designed to: simulate the action of weathering agents on buildings and identify the underlying mechanisms, determine the salt resistance of different types of rock; evaluate consolidation and water-repellent treatment durability; and confirm hypotheses about the origin of salts such as gypsum that are often found in granite buildings. Salt crystallization tests were also conducted, using sodium chloride, sodium sulphate, calcium sulphate and seawater solutions. One of these tests was conducted in a chamber specifically designed to simulate salt spray weathering and another in an SO2 chamber to ascertain whether granite is subject to sulphation. The test results are analyzed and discussed, along with the shortcomings of each type of trial as a method for simulating the decay observed in monuments. The effect of factors such as wet-dry conditions, type of saline solution and the position of the planes of weakness on the type of decay is also addressed.En este trabajo se hace una síntesis de varios ensayos de alteración artificial realizados con rocas graníticas. Estos ensayos tenían distintos objetivos: reproducir las formas de alteración encontradas en los edificios para llegar a conocer los mecanismos que las generan, determinar la resistencia de las diferentes rocas a la acción de las sales, evaluar la durabilidad de tratamientos de consolidación e hidrofugación y constatar hipótesis acerca del origen de algunas sales, como el yeso, que aparecen frecuentemente en edificios graníticos. En los ensayos de cristalización de sales se utilizaron disoluciones de cloruro de sodio, sulfato de sodio, sulfato de calcio y agua de mar. Uno de estos ensayos se llevó a cabo en una cámara especialmente diseñada para reproducir la alteración por aerosol marino y otro se realizó en una cámara de SO2, con el objeto de comprobar si en rocas graníticas se puede producir sulfatación. Se analizan los resultados obtenidos en cada ensayo y se discuten las limitaciones de los mismos para reproducir las patologías desarrolladas en los monumentos así como la influencia que pueden tener en dichas patologías aspectos como las condiciones de humectación y secado, el tipo de disolución salina (mixta-simple y la influencia de los planos de debilidad de las rocas en el desarrollo de unas u otras formas de alteración.

Silva Hermo, B.

2008-06-01

97

Geology of the Northern part of the Strath Ossian Granite, Scotland  

International Nuclear Information System (INIS)

The Strath Ossian Granite is made up of granodiorite, dark, variable 'granodiorites' interpreted as mobilised diorite or basic material, appinite and porphyritic granodiorite. Huge rafts of psammitic metasediments occur within the mass and three fracture-zones and numerous dykes, dominantly of porphyrite, cut across it in a north-easterly direction. Granite emplacement may have occurred in stages, early batches being xenolith-rich and later ones xenolith-poor. New batches were intruded centrally, which created strong radial stresses, sufficiently strong to make room for the intrusion by forcing the metasedimentary country rocks downwards and aside. (author)

1982-01-01

98

Dirty or Tidy ? Contrasting peraluminous granites in a collapsing Orogen: Examples from the French Massif Central  

Science.gov (United States)

Post collisional collapse commonly enhances crustal melting. Such melting typically produces peraluminous granitic magmas. In the French Massif Central, a mid-crustal segment of the western Variscan belt, two large granitic bodies were produced during the collapse of the Variscan Belt. The St Sylvestre Leucogranitic Complex (SSyL) in the western part of the Massif Central and the Velay Migmatitic Complex (VMC) in the Eastern part. Although these two complexes are formed in similar geodynamic context they present meaningful petrological and geochemical differences. The VMC (~305 Ma) is clearly intrusive in migmatitic terranes. The migmatitic host recorded two successive melting events M3 (720 °C and 5kb) dated between 335 and 315 Ma and M4 (850°C and 4 kb) dated at 305 Ma. The compositions of the VMC are strictly H2O-undersaturated and ranges from leucogranitic to granodioritic. Three main successive granite types have been distinguished (1) A heterogeneous banded biotite granite, (2) A main biotite-cordierite granite, where cordierite can be prismatic, as cockade or pseudomorphic (3) a late magmatic with large K-feldspar phenocryst and prismatic cordierite. The compositions of the VMC granites are quite similar to typical Australian S-type granites in the sense that they also show a positive correlation between ferromagnesian abundance and aluminosity. The SSyL (~320 Ma) is intrusive in upper greenschist facies to upper amphibolite migmatitic metasediment and orthogneiss (~3kb). The compositional variety observed in the SSyL suggests a continuous trend from a moderately mafic, peraluminous magma (cd- and sill- granite) to a H2O saturated granite ("two-mica" granite) facies and finally to an extremely felsic, H2O-saturated magma. Three granitic units have been recognized in the SSyL: (1) the western "Brame Unit" composed of the less evolved cd- and sill- granite facies (2) the central "St Sylvestre Unit", composed mainly by U-rich two-mica granite, intruded by two synchronously emplaced fine grained granites to its western margin: "Fanay" (biotite dominant) and "Sagne" (Li-muscovite only) (3) the eastern "St Goussaud Unit" mostly composed of a muscovite-dominant leucogranite surrounded by Sn-W mineralization. The compositions in the SSyL have a weak ferromagnesian character, negatively correlated with aluminosity and are quite similar in composition to High Himalayan syn-collisionnal peraluminous granite (e.g. Manaslu) Compositional trend of the VMC granite can be easily mimicked by the addition of peritectic material (i.e. produced during incongruent biotite melting) to experimental melts produced through the melting of metasediments (Dirty). Compositions of the SSyL are similar to experimental melt only (Tidy). Such differences in composition could be the results of different processes: 1) Different melting reactions as a consequence of different conditions of melting (e.g. different source composition, temperature). 2) The peritectic phases remained "trapped" in the source during melt extraction due to the structuration of the source or a lower melt viscosity (e.g. higher F, Li, H2O contents). Interestingly, while within dirty granites, peritectic phase entrainment controls compositional variability, Tidy granites display original melt compositional variability as well as the potential effects of late magmatic processes.

Villaros, Arnaud; Pichavant, Michel; Moyen, Jean-François; Cuney, Michel; Deveaud, Sarah; Gloaguen, Eric; Melleton, Jérémie

2013-04-01

99

Uranium enriched granites in Sweden  

International Nuclear Information System (INIS)

Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by (1) the anatexis of continental crust (2) processes occurring at a much greater depth. They commonly show enrichement in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (Authors)

1979-12-01

100

K-Ar ages of granitic inclusions from the Futamata and Tomuraushi pyroclastic flow deposits in central Hokkaido, Japan  

International Nuclear Information System (INIS)

The pliocene Futamata and Tomuraushi pyroclastic flow deposits and their granitic inclusions in central Hokkaido, form a series of volcano-plutonic association. The newly obtained K-Ar ages of the granitic inclusions are 1.1-1.2 Ma for whole rocks. These K-Ar ages are much younger than the ages which are expected from stratigraphic correlation. This discrepancy in age suggests loss of radiogenic "4"0Ar from the pyroclastic flow deposits and their granitic inclusions during thermal event of subsequent volcanism. (author)

1985-01-01

 
 
 
 
101

Granites and granitoids of the southern region - Granite molybdenite system  

International Nuclear Information System (INIS)

Economic concentrations of molybdenum are genetically closely associated with acidic and moderately acid granitoids-granites, granodiorites, monzonites and diorites, and are located in two geotectonic settings: subduction-related and rift-related. The aim of this paper is twofold, first succinctly approach the geology, tectonic setting and chemical parameters of the 'granite molybdenite system' as defined by Mutschler and/or alcali granite porphyry bodies emplaced in the North American continent for occasion of a Mesozoic-Fanerozoic extensile event; second to relate the computer-assisted evaluation of 422 major element chemical analysis of granites and granitoids of southern region of Brazil, using chemical fingerprints (SiO_2 ? 74. Owt%, Na_2O ? 3.6wt%, K_2O ? 4.5wt%), and K_2O/Na_2O ratio > 1.5 developed and testified from North American and Finnish occurrences, may locate molybdenite-bearing granite bodies with high exploration potential. These techniques suggest that some late Precambrian to early Paleozoic granite-rhyolite assemblages inserted at domains of the SG. 22/23 Curitiba/Iguape, SH. 21/22 Uruguaiana/Porto Alegre and SI.22 Lagoa Mirim Sheets, have exploration potential for molybdenum. (author)

1987-11-02

102

Geophysical model of geological discontinuities in a granitic aquifer: Analyzing small scale variability of electrical resistivity for groundwater occurrences  

Science.gov (United States)

Geological discontinuities such as quartz reef, a common geological feature in hard rock terrain occurring as an intrusive body, has been investigated using geophysical methods in order to explore and map the potential aquifer. Electrical resistivity response of quartz reef intrusive in granite host rock has been studied using synthetic simulation for different physical conditions such as: (1) fresh intrusive body with no alteration at contacts, (2) fresh intrusive body with weathered-fissured contacts, and (3) also fissured intrusive body with weathered-fissured contacts. Electrical Resistivity Tomography (ERT) was carried out traversing across and along the quartz reef at Kothur village, Hyderabad, India. Based on the ERT results 11 bore wells have been drilled followed by yield measurement, litholog collection, and electrical resistivity logging. Geomorphology, ERT images, lithologs, resistivity logs and yield of the wells are found corroborating with each other. Deepening of the weathering fronts are confirmed along the contacts of the quartz reef and granite, which may qualify suitable sites for groundwater occurrence. This has been finally validated from the drilling results, where high yielding (18 m 3/h) bore well found at low resistive zones within the quartz reef. The study has helped in preparing a 2D section of the structural set up of the quartz reef in granite host medium and finally revealed that the quartz reefs may provide potential groundwater zone. The distribution of electrical resistivity of the geological discontinuity is useful providing promising input to the groundwater flow model particularly in three dimensional.

Chandra, Subash; Dewandel, Benoit; Dutta, Sushobhan; Ahmed, Shakeel

2010-08-01

103

Labile uranium in granitic rocks  

International Nuclear Information System (INIS)

Labile uranium in granitic rocks has been proposed as the source for many ore deposits. Tests of this hypothesis or development of commercial in-situ leaching of uranium from crystalline rocks will require analytical techniques that can be used to identify granites that contain labile uranium. U-Th-Pb isotopic systematics can be used to obtain quantitative or semi-quantitative data on the timing and extent of uranium mobilization, but the technique is limited to Precambrian rocks and is too expensive for general use as an exploration tool. Granite from the Granite Mountains, Wyoming, has been shown to contain labile uranium, and it is proposed that several characteristics of this granite may be typical of other granites that are possible uranium source rocks. Important characteristics for uranium source rocks are inferred to be (1) alkalic affinity and high (>70%) silica content, (2) high Th content, and (3) disequilibria between pairs of long-lived radiogenic daughter products within the 238U-decay chain. This last characteristic may possibly be identified by comparing RaeqU values (radium equivalent uranium obtained by ?-ray spectrometry) with chemical uranium contents. (author)

1976-04-02

104

WLAN Intrusion Detection System  

Directory of Open Access Journals (Sweden)

Full Text Available This is an implementation of the Wireless LAN Intrusion Detection System (WIDS using clock-skews as a fingerprinting property as suggested by Jana-Kasera [1]. Our objective is to detect the presence of a fake access point (AP in a Wireless LAN (WLAN. Use of clock -skew enables us to effectively detect Medium Access Control (MAC Address spoofing. The principle used in this project is that clock s k e w s remain consistent over time for the same AP but vary significantly across AP’s. We have also tried to exploreprobable points of failure and implemented algorithms to overcome these problems. Advantage of this implementation is that fake AP can be detected very quickly as WLAN Intrusion Detection System needs only 100 -200 packets in most cases.

Ms. Sushama Shirke

2011-08-01

105

Intrusion detecting device  

International Nuclear Information System (INIS)

An intrusion detecting device comprises a grid of tubes spaced apart by a distance d sufficient to impede an intruding body. Each tube contains a radioactive luminescent source which transmits radiation that is confined to a narrow beam by a series of aligned apertured masks. A detector receives the radiation and provides an input to an AND-gate connected to alarm circuitry. The radiation is diverted from the detector if the respective tube is deformed or deflected hence providing a signal to indicate an intrusion. The tubes may form part of a device for preventing an intruder from gaining access to a security zone. Alternatively, the tubes may be flexible to enable the passage of, e.g. fish to be counted. An alternative embodiment employs intercommunicating tubes with mirrors for guiding radiation from a common source to a common radiation detector. (author)

1985-04-24

106

Interior intrusion alarm systems  

International Nuclear Information System (INIS)

In meeting the requirements for the safeguarding of special nuclear material and the physical protection of licensed facilities, the licensee is required to design a physical security system that will meet minimum performance requirements. An integral part of any physical security system is the interior intrusion alarm system. The purpose of this report is to provide the potential user of an interior intrusion alarm system with information on the various types, components, and performance capabilities available so that he can design and install the optimum alarm system for his particular environment. In addition, maintenance and testing procedures are discussed and recommended which, if followed, will help the user obtain the optimum results from his system

1978-01-01

107

Perimeter intrusion sensors  

International Nuclear Information System (INIS)

To obtain an effective perimeter intrusion detection system requires careful sensor selection, procurement, and installation. The selection process involves a thorough understanding of the unique site features and how these features affect the performance of each type of sensor. It is necessary to develop procurement specifications to establish acceptable sensor performance limits. Careful explanation and inspection of critical installation dimensions is required during on-site construction. The implementation of these activities at a particular site is discussed

1977-01-01

108

Wireless Intrusion Prevention Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The wireless networks have changed the way organizations work and offered a new range of possibilities, but at the same time they introduced new security threats. While an attacker needs physical access to a wired network in order to launch an attack, a wireless network allows anyone within its range to passively monitor the traffic or even start an attack. One of the countermeasures can be the use of Wireless Intrusion Prevention Systems.

Timofte, Jack

2008-01-01

109

Geothermal potential of Caledonian granites underlying Upper Palaeozoic sedimentary basins astride the Iapetus Suture Zone in Ireland  

Science.gov (United States)

Upper Palaeozoic sedimentary basins in Ireland overlie crystalline rocks within the Caledonian Iapetus Suture Zone. Beneath these basins, Lower Palaeozoic rocks, formed and deformed during the Caledonian orogenic cycle, were intruded by c. 420-390 Ma late-tectonic granites at various tectonic levels. These include the subsurface Kentstown and Glenamaddy granites discovered by mineral exploration drilling. While these granites comprise actual targets for Enhanced Geothermal System (EGS) exploration, several others likely exist based on geophysical considerations. In order to test the regional geothermal potential, the buried granites as well as analogue exposed rocks are being investigated geochemically. The geothermal potential of the intrusives depends on their heat production rate (HPR), which is calculated using rock density and concentrations of the heat producing elements (HPE) uranium, thorium and potassium. In spite of their close spacing and similar ages, the whole-rock geochemistry of the granites varies significantly, but with no obvious geographical control (Fritschle et al., 2013; 2014). The granite HPR values range from 1.4 ?W/m3 for the Dhoon Granite (Isle of Man) to 4.9 ?W/m3 for the Drogheda Granite (Ireland). This compares with the average HPR for a 'typical' granite of 2.7 ?W/m3 (Goldstein et al., 2009). It is demonstrated that an elevated HPR of a granite can be related to enrichment in one of the HPE alone (e.g., uranium-enrichment in the Foxdale Granite (Isle of Man), or thorium-enrichment in the Drogheda Granite). Enrichment in HPE in a granite may occur due to different reasons including hydrothermal (re-) distribution of uranium, or the assimilation of thorium-rich wall-rocks. Hence, the distribution of the HPE in particular minerals, veins and source lithologies, along with the petrophysical characteristics of the sedimentary basins and the granites' petrogenesis, are currently being investigated as possible mechanisms controlling their heat production budget. Fritschle, T., Daly, J.S., Whitehouse, M.J., McConnell, B., Buhre, S., 2013. U-Pb Zircon Ages from Granites in the Iapetus Suture Zone in Ireland and the Isle of Man. Mineralogical Magazine, 77(5): 1115. Fritschle, T., Daly, J.S., Whitehouse, M.J., McConnell, B., Buhre, S., 2014. Zircon geochronology and Hf-O isotope geochemistry from granites in the Iapetus Suture Zone in Ireland and the Isle of Man. This issue. Goldstein, B.A., Hill, A.J., Long, A., Budd, A.R., Ayling, B., Malavazos, M., 2009. Hot rocks down under - evolution of a new energy industry. Geothermal Resources Council Transactions, 33: 185-198.

Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; McConnell, Brian; Buhre, Stephan

2014-05-01

110

Experimental strategies for the investigation of low temperature properties in granitic and pegmatitic melts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The physical behavior of silicate melts during the final stages of intrusion in the earth's crust are poorly understood. In particular, the low temperature limit of igneous petrogenesis is poorly constrained. The extreme differentiates of granitic magmatism that lead to pegmatite genesis span a very large range of composition not normally considered to be within the domain of igneous melt compositions. This combination of very low petrogenetic temperatures and extreme chemistries requires a c...

Dingwell, Donald B.

1993-01-01

111

Geochemical, petrological, geo dynamic and radiometric age dating investigation of Aqdarreh intrusion massive (north of Takab) northwest of Iran  

International Nuclear Information System (INIS)

Aqdarreh intrusi body with an area of 30 km 2 is located in 34 km north of Takab, northwest of Iran. This batholith is situated in Central Iran, cutting Paleozoic rocks. Radiometric age of Aqdarreh batholith by K-Ar method is 48.38 m. a.,corresponding to Eocene magmatism. Aqdarreh intrusive body consists of tonalite, granodiorite, alkali feldspar granite and monzogranite in which the main mafic mineral is biotite. Further more, there is not any enclave in these rocks. Study of the investigated samples shows that Aqdarreh intrusive rocks have two different generations. Part of the collected samples belongs to I-type granite (calc-alkaline) and others represent the A-type granite (alkaline). It seems that this process is created by the contamination of alkaline magma by crustal materials. Geochemistry of the rare earth elements shows that the tectonic setting of the body is compatible with Post Orogenic Granitoids

2005-01-01

112

Uranium deposits in granitic rocks  

International Nuclear Information System (INIS)

This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

1977-01-01

113

Contrasting episodic emplacement and growth modes of the dumbbell-shaped Guposhan-Huashan twin granitic plutons in Nanling Range of south China  

Science.gov (United States)

The Guposhan-Huashan twin plutons occur as a complex batholith in the Middle Mesozoic Central Nanling Range granitic belt in south China. Both plutons show concentric zoning patterns and are composed of two distinctive emplacement sequences separated by an approximately 9 m.y. magmatic lull, based on field mapping and observations, geochronology, and geochemistry. The earlier sequence is the 160 -163-Ma Niumiao-Lisong-Wanggao sequence and the later one is the 148 - 151-Ma Xinlu-Huamei sequence. Assisted by dominant vertical heat flow and uplifting of the roofs, the Niumiao-Lisong-Wanggao-sequence magmas were episodically emplaced in an over-accretion style as distinguishable incremental intrusive units during an approximately 3 m.y. span. Gravity data, observations of field relationships, as well as analysis of finite strain and country rock rheology confirm that both plutons became thickened considerably due to largely vertical assembling and growth, and most of their space was created by vertical displacement of their country rocks. However the coeval twin plutons show contrasting development and growth modes during their assembling and thickening process. The Guposhan pluton was built on an "outward building" mode with a "reverse-zoning" pattern while the Huashan pluton on an "inward building" mode with a "normal-zoning" pattern. We propose that the contrasting modes largely resulted from their divergent thermal evolution path. For example, the incremental inward building mode helped retain thermal energy and maintain a high temperature of the pluton, which facilitated subsequent inward building of later incremental intrusive units. However, due to evolving crustal thermal and rheological conditions, the younger Xinlu-Huamei-sequence magmas were controlled by shallower brittle faults and emplaced within the early-sequence plutons as stocks and dykes by a dyke-propagation mechanism.

WANG, C.; Feng, Z.; Zhang, M.; Liang, J.

2011-12-01

114

Speciation in granitic melts  

Energy Technology Data Exchange (ETDEWEB)

Refinement of the cryoscopic equations for the major granitic melt components, NaAlSi/sub 3/O/sub 8/(ab), CaAl/sub 2/O/sub 8/(an), KAlSi/sub 3/O/sub 8/(or), and Si/sub 4/O/sub 8/(qz), has led to the recognition of several major speciation reactions in anhydrous and hydrous melts of the system Ab-An-Or-Qz-H/sub 2/O. These reactions involve either dissociation of the feldspar-like components, as in incongruent melting, or interaction between them and qz. In all cases of interaction, one of the speciation products has the stoichiometry of dpy or py (pyrophyllite) (Al/sub 1.455/Si/sub 2.91/O/sub 8/ +/- 0.73H/sub 2/O), in which Al is presumed to be in either fivefold (dpy) or sixfold (py) coordination. The py component also is a major product of speciation by interaction between sil (Al/sub 3.2/Si/sub 1.6/O/sub 8/) and qz in peraluminous melts of the system Ab-Or-Qz-Sil-H/sub 2/O; as a consequence, the quartz liquidus field boundary is shifted to lower temperatures and toward qz. There is no evidence in peraluminous haplogranite melts for the existence of a muscovite-like species. Application of the refined thermodynamic model to the system Ab-Qz-Eu - H/sub 2/O at 2.0 kbar predicts the occurrence of a eu and qz-consuming reaction that produces a petalite-like species and a consequent dramatic shift in liquidus field boundaries. Higher pressures favor conversion of pe to qz + sp. In the spodumene-like species, sp, Al presumably is six-coordinated.

Burnham, C.W.; Nekvasil, H.

1985-01-01

115

Petrochemical characteristics of Serra do Meio alkaline granite (Campo Alegre de Lourdes - Bahia State)  

International Nuclear Information System (INIS)

The Serra do Meio granite outcrops near the town of Campo Alegre de Lourdes, north-northeast of Bahia State. The granite is intrusive into micachists, which are correlatives of the Salgueiro-Cachoeirinha Group (Early Proterozoic), during early to the syn-tectonic shear phase. The geological setting also comprises a phosphatic rock-bearing carbonatitic complex and gabbroid complexes with one of the main world resources of Fe-Ti-V. The granite mineralogical composition grades from Aegerine-augite alkali-feldspar granite/syenites to Leuco alcali-feldspar granite. The geochemical analysis shows SiO_2-enrichment (67 to 76%), in alkalis (Na_2+K_2O, 7,5 to 12,5%), Nb (up to 680ppm), Zr (up to 2,390ppm), Y (up to 250ppm) e REE (up to 796ppm). The geochemical behaviour is peculiar to alkaline series, denoting a silica-oversaturated, potassium-rich, magma. The chondrite-normalized REE patterns display a first group with smooth slopes from the La to Lu, and a second one with negative slopes. Negative Eu anomalies are displayed in all the patterns. The first group is HREE-enriched, with low fractionation ratios. Samples with milonytic fabrics and higher fractionation ratios are related to the second group, suggesting the interaction of metassomatic fluids and the alkaline magma. Discriminant diagrams for Nb, Y and Rb, coupled with geophysical data, point to an intrusive granite in an extensional within a plate tectonic setting of attenuated continental crust. (author)

1989-10-01

116

The Rb-Sr age of the Sundsta granite in the Western Pregothian tectonic mega-unit, south-western Sweden  

International Nuclear Information System (INIS)

The Sundsta granite is a reddish, acidic granite, situated in the Western Pregothian mega-unit in Vaermland, south-western Sweden. Its Rb-Sr whole-rock age is 1566+-39 Ma with an initial ratio 0f 0.705 +-0.003. The region is dominated by grey, migmatized granitoids presumably belonging to the Aamaal-I group which has ages of 1650-1700 Ma. The marked difference in degree of migmatization between these two rock-units may indicate that the intrusion of the Sundsta granite post-dates the main migmatization phase of the Aamaal-I granitoid in this region. (Authors)

1982-10-25

117

Intrusive growth of sclerenchyma fibers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intrusive growth is a type of cell elongation when the rate of its longitudinal growth is higher than that of surrounding cells; therefore, these cells intrude between the neighboring cells penetrating the middle lamella. The review considers the classical example of intrusive growth, e.g., elongation of sclerenchyma fibers when the cells achieve the length of several centimeters. We sum the published results of investigations of plant fiber intrusive growth and present some features of intru...

Snegireva, A. V.; Ageeva, M. V.; Amenitskii, S. I.; Chernova, T. E.; Ebskamp, M.; Gorshkova, T. A.

2010-01-01

118

Release of uranium through cataclastic deformation of Mansehra granite gneiss and its precipitation in the overlying intramontane basin in northern Pakistan  

International Nuclear Information System (INIS)

The Mansehra pluton belongs to a discontinuous belt of two mica granites of the Lesser Himalayas. The Mansehra granite is generally foliated except in the area around Mansehra. Several phases of granitic activity have been reported from the Mansehra Complex. Shams and Rahman have demonstrated that the younger phases tend to be enriched in Na2O. Ashraf extensively studied minor bodies ranging from albitites through aplites to pegmatites and suggested a late stage albitization event. The northern edge of this sheet-like granitic mass has undergone extensive cataclastic deformation, resulting in the formation of shear zones, mylonites and cataclasites. A chemical comparison of crushed granite with granite outside the shear zone suggests little chemical reconstitution in terms of major elements during cataclastic deformation. A huge shear zone in albitized granite gneiss has yielded secondary uranium minerals at water seepages, suggesting a liberation of uranium. Hydrogeochemical surveys of the crushed granite and adjoining areas suggest that uranium from crushed granite was easily leachable in comparison with rocks outside the shear zone. The uranium thus liberated was trapped in a Pleistocene sequence of clays and unsorted fluviatile sand overlying the granite and country rock metamorphics. (author). 17 refs, 2 figs, 2 tabs

1986-10-03

119

Petrophysical properties of granite from the Melechov Massif, Czech Republic  

Science.gov (United States)

The Melechov Massif is a granitic massif constituting the northernmost part of the Central Moldanubian Pluton, which belongs to the Moldanubian zone of the variscan belt in the Bohemian Massif. On an area of cca 100 km2 it is formed by 4 types of granite which are disposed in a concentric manner and are distinguished mainly by their grain size. All the granites are two-mica S-granites considered to be product of polyphase intrusion of magma issued from partial melting of the surrounding variscan metasediments. Relative to the variscan orogeny, the granites are considered to be post-orogenic and are related to isothermic decompression of upper- to middle-crust during collapse of the orogeny-thickened lithosphere. Ages of cooling derived from radiometric dating on monazites give values for all of the types 315 ± 10 Ma. The granite massif suffered brittle deformation related to cooling and induced volume contraction creating systems of joints and, in a lesser measure, faults. The Melechov massif was intensely studied during the last two decades, mainly because it has been established as a testing locality by the radioactive waste repository authority (RAWRA) of the Czech Republic. We have the intention to complement the studies done so far by detailed petrophysical and microstructural analysis of samples taken with respect to macroscopic brittle structures. Several methods are employed to reveal important differences in rock samples collected from distinct geological setting from surface outcrops, quarries and a borehole. The concerned petrophysical properties and/or related experimental methods are namely: thermal conductivity, permeability, porosity, P-wave velocity measurements; in most cases the anisotropy of these quantities is crucial. Preliminary analyses of permeability and porosity show low porosity ranging from 3,8 % for coarse-grained variety to 1,3 % for fine-grained variety and very low permeability ranging from X.10-18 m2 for fine-grained variety to X.10-20 m2 for coarse-grained variety. Preliminary analyses of P-wave velocity at low confining pressures (increase of about 10 %. To specify and to increase the confidence of our results on borehole samples, which are suspect to be critically too small relative to the prerequisities of the used TC method, we will investigate the influence of volumetric dimensions of sample on the TC values as well as the possible error induced by measurement on a cylindrical surface as compared to measurement on an „infinite' sample.

Stanek, Martin; Ulrich, Stanislav; Geraud, Yves

2010-05-01

120

Geochemistry of biotite granites from the Lamas de Olo Pluton, northern Portugal  

Science.gov (United States)

In the Central Iberian Zone (CIZ) extensive crustal recycling occurred during the post-thickening extension stage of the Variscan orogeny (~330-290 Ma). After the ductile deformation phase D3 (~320-300 Ma), characterized by the intrusion of large volumes of highly peraluminous granitic magmas, rapid and drastic tectonic changes at about 300 Ma gave rise to the brittle phase of deformation D4 that controlled the emplacement of Fe-K subalkaline granites (296-290 Ma; Dias et al. 1998). The Lamas de Olo Pluton (LOP) is controlled by NE-SW and NW-SE fracture systems, probably related to the Régua-Verin fault zone (Pereira, 1989). The LOP is a medium to coarse-grained, porphyritic biotite granite, accompanied by medium- to fine grained, porphyritic biotite granite (Alto dos Cabeços- AC) and a more leucocratic, fine-grained, slightly porphyritic biotite-muscovite granite (Barragens- BA). The contacts between LO and AC are generally diffuse, whereas those to BA are sharp. In fact, the BA granite can occur in dykes and sills cutting LO and AC. Microgranular enclaves and xenoliths are very rare. The LOP intrudes the Douro Group, presumably of Precambrian to Cambrian age, and two-mica granites from the Vila Real composite massif. The LOP granites consist of quartz, microcline, plagioclase, biotite, zircon, titanite, tourmaline apatite, fluorite, ilmenite, magnetite, and rutile, with muscovite in BA granite and rare allanite in the LO and AC granites. The plagioclase composition is of oligoclase (An12) - andesine (An35) for LO granite, albite (An9) - andesine (An30) for CA granite and albite (An5) - oligoclase (An20) for BA granite. There are decreases in: a) anorthite content from phenocryst to matrix plagioclase; b) Ba content from phenocryst to matrix microcline in all granites. The Fe2+ biotite has a composition similar to that of biotite from calc-alkaline to sub-alkaline rock series. The LO and AC granites are meta- to peraluminous with ASI variable between 1.05 and 1.21, and display isotopic signatures of (87Sr/86Sr)i = 0.7044-0.7077 and Nd = -2.2 to -1.1. Six samples of LO define a whole rock isochron age of 285±15 Ma with (87Sr/86Sr)i = 0.7051±0.001 (MSWD = 0.11). Two monazite analyses for the LO granite yield an weighted average 207Pb/235U age of 297.19±0.73 Ma, consistent with the preliminary ID-TIMS U-Pb analyses of two transparent and euhedral prisms of zircon that define a concordia age of 296.37 ±0.52 Ma (MSWD = 0.66). The linear trends of major and trace elements variation diagrams of LO and AC granites and their similar mean values of (87Sr/86Sr)i point, at this stage, to an involvement of mid-crustal sources, probably mixed with asthenospheric material. Therefore, LOP consists of post-D3 biotite granites installed in higher structural crustal levels, testifying the occurrence of a crustal growth episode after the major recycling processes that occurred during the deformation phase D3. We thank Prof. J.F. Santos and Dr. S. Ribeiro and Petrochron project (PTDC/CTE-GIX/112561/2009) for the Rb-Sr isotopic data obtained at LGI of University of Aveiro, Portugal. Dias, G. et al. 1998. Lithos, 45, 349-369. Pereira, E., 1989. Serviços Geológicos de Portugal.

Fernandes, Susana; Gomes, Maria; Teixeira, Rui; Corfu, Fernando

2013-04-01

 
 
 
 
121

DRM – Intrusion or Solution?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

DRM could be the solution to the content industry’s P2P dilemma, but content owners’ desire to monitor and control the consumer’s use of content can be perceived as an intrusion of privacy. High control makes consumers less active and low control invites them to experiment and to gain experience. Digital music files can easily be spread. Therefore legal services prefer keeping control over the music. This study reveals that consumers are one step ahead of the content industry, finding w...

Blomqvist, Ulf; Fritzell, Michael; Olofsson, Marcus

2005-01-01

122

Distributed Intrusion Detection System  

Science.gov (United States)

Internet worms and other malicious code often scan firewalls to determine which ports are unprotected. While firewall users have access to their port scanning data in the form of log files, most do not make use of it. The Distributed Intrusion Detection System remotely monitors trends in worldwide port scanning, and the data it has collected is available at this site. The data can be used by Internet professionals for early detection of worms or for implementing improved security measures. Firewall users can contribute to this project by downloading the free DShield Client, which automatically sends log reports for inclusion in worldwide data or by submitting logs online via a Web interface.

123

Acoustic emission intrusion detector  

International Nuclear Information System (INIS)

An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal

1980-01-01

124

Origin of postcollisional intrusions in NW Anatolia, Turkey: Implications for magma chamber processes  

Science.gov (United States)

Post-collisional magmatic activities of NW Anatolia are represented by a series of granitic intrusions and volcanic successions in the Biga Peninsula, NW Turkey. These plutonic rocks have distinct textures, chemical compositions and Sr-Nd isotope characteristics. They consist of coarse grained, equigranular and/or hypidiomorphic textured granite, gronodiorite, monzogranite, quartz-monzonite, pyroxene-monzonite and leucocratic alkali feldspar granites. These intrusions are composed of quartz, K-feldspar, plagioclase, hornblende, pyroxene and biotite. However, leucocratic facies rocks contain tourmaline with minor amount of mafic minerals. Accessory phases are represented by zircon, apatite, monozite, magnetite, sphene and rarely allanite. ASI values of the plutonic rocks vary between 0.7 and 1.24. These intrusive rocks are therefore classified as metaluminous-peraluminous with I-type affinity. K2O contents show that the intrusive rock samples show calc-alkaline, high K-calc-alkaline and shoshonitic character. Initial 87Sr/86Sr(t) (0.69980-0.70835), 143Nd/144Nd(t) (0.51238-0.51247) isotope ratios and negative ?Nd(t) (-4.4 - -2.6) values imply that these intrusive rocks could have been derived from enriched mantle sources. N-MORB normalized spidergrams of NW Anatolian plutonic rocks display enrichments in large ion lithophile elements (LILE), light rare earth elements (LREE) and depletion in high field strength elements (HFSE) indicating hydrous melting of a mantle wedge in a subduction zone and/or enrichment of the mantle source with an inherited subduction component from an ancient arc magmatism. Chondrite-normalized Rare Earth Element spidergrams are indicative of the importance of plagioclase and amphibole fractionation. On tectonic discrimination diagrams, all granite samples fall into the volcanic arc granite, syn and post-collisional granite fields. The geochemical data also indicate that a number of magma chamber processes involving magma mixing, fractional crystallization (FC) and assimilation with fractional crystallization (AFC, EC-AFC) might have been operational during the magma chamber evolution. These stocks were dated by using K/Ar method on hornblende, biotite and whole rock samples and U/Pb LA-ICP-MS zircon dating, yielding ages between 20.2±0,9 Ma and 27.89±0,17 Ma (Upper Oligocene - Lower Miocene). The widespread Upper Oligocene - Lower Miocene plutonism in NW Turkey is thought to be linked to crustal thinning resulted from slab roll-back and syn-convergent extensional regime after the collision between the Sakarya Zone and Anatolide-Tauride platform.

Aysal, Nam?k

2013-04-01

125

Molybdenite in Pomona Island Granite at Lake Manapouri, Fiordland  

International Nuclear Information System (INIS)

A small occurrence of molybdenite (MoS2) mineralisation has been discovered in the weakly A-type Pomona Island Granite on the shorelines of Lake Manapouri in eastern Fiordland. The disseminated appearance of molybdenite and the absence of quartz veins indicates that mineralisation is probably the product of magmatic and/or hydrothermal activity related to pluton crystallisation at c. 157 Ma, and not younger (c.128-116 Ma) shear zone-related mesothermal mineralisation as has been recently described from the Murchison Mountains to the north and Stewart Island to the south. Although apparently not of economic grade, the Pomona Island Granite locality is regionally important because it is the first direct pluton-related Mo-mineralisation event to be recognised in eastern Fiordland. This occurrence adds to the growing number and known styles of base metal occurrences within the Jurassic-Cretaceous magmatic arc (Outboard Median Batholith) that formed on or near the New Zealand Gondwana margin. Furthermore, the wide distribution of essentially uninvestigated A-type granites in the Outboard Median Batholith means that there may be further Mo-mineralised localities awaiting discovery. (author). 20 refs., 3 figs., 1 tab.

2011-09-01

126

Re-Os molybdenite dating of granite-related Sn-W-Mo mineralization at Hnilec, Gemeric Superunit, Slovakia  

International Nuclear Information System (INIS)

Re-Os molybdenite ages from the exocontact of the Hnilec granite-greisen body provide temporal constraints for tin, tungsten and molybdenite mineralization in the Gemeric Superunit, Slovakia. Two molybdenite separates were taken from a representative sample of the Sn-W-Mo mineralization at Hnilec and their Re-Os ages of 262.2 ± 0.9 and 263.8 ± 0.8 Ma (2-sigma) are in excellent agreement. The obtained Re-Os molybdenite ages are similar to recent but less precise electron microprobe monazite (276 ± 13 Ma) and U-Pb single zircon (250 ± 18 Ma) ages from the Hnilec granite intrusion, supporting a granite-related greisen origin for the Sn-W-Mo mineralization. Our precise Re-Os molybdenite ages resolve the long time controversy over the timing of high-temperature mineralization in the Gemeric Superunit. These Permian ages eliminate suggestions of an Alpine age. The sulphur isotope composition of the studied molybdenite is ?34S(CDT) = 1.71 ± 0.2 %o and is consistent with a magmatic sulphur source. Field observations indicate the lack of a broad contact aureole in the vicinity of the Hnilec granite body. Shallow level granite emplacement in schistose host rocks was accompanied by alteration and formation of tin-tungsten greisen in the upper part of the granite and exocontact molybdenite mineralization, both commonly lacking in other granite bodies within the Gemeric Superunit. (author)

2005-01-01

127

Spatial and temporal relationships between granites and porphyry copper deposits in northern Chile  

Science.gov (United States)

Chile is the leading copper producing country in the world, hosting ~30% of known worldwide copper reserves. Subduction-related magmatism in Chile has been ongoing since at least Mesozoic time, with progressive inland migration of the magmatic arc from the Jurassic coast eastward to the active western cordillera in the high Andes. Porphyry copper deposits (PCDs) in Chile are spatially and temporally related to emplacement of shallow, felsic to intermediate composition plutons that sourced the ore-forming magmas and mineralising fluids. However, not every such intrusion in Chile is associated with a mineralised deposit, suggesting that there are other controls on whether or not an intrusion hosts a PCD. Models for porphyry copper formation typically assume emplacement of these felsic to intermediate intrusions at shallow crustal levels (5-15 km depth) [1], but absolute constraints on emplacement depths for both mineralised and barren systems are lacking. In order to explore the relationship between granite emplacement depths and occurrences of PCDs in northern Chile, we have created a geospatial database that compares the age, geochemistry, and depth of mapped felsic to intermediate plutons (e.g. granites, tonalities, and diorites) with the locations of known PCDs, as well as major fault zones and volcanic centres. Emplacement depths have been calculated from published geochemical analyses using existing calibrations of the Al-in-hornblende barometer, which is widely used for calc-alkaline granitic rocks [2]. We are also developing a new experimental calibration of the barometer using a combination of piston cylinder experiments (5, 7, and 10 kbar), externally heated pressure vessel experiments (0.5-2 kbar), and electron microprobe analyses on a granitic sample of the Lluta batholith, collected in northern Chile. This improved Al-in-hornblende barometer, calibrated for shallow intrusions, will provide a viable alternative to estimating depths of PCD formation from fluid inclusions, which is often hampered by alternations between lithostatic and hydrostatic pressure. Furthermore, the results of this study will be broadly applicable to investigating the potential links between intrusion depth, PCD formation, and parameters such as regional tectonic patterns and fluid/melt interactions. References: [1] Sillitoe, 2010, Porphyry Copper Systems, Ec. Geol., 105, 3-41. [2] Anderson et al., 2008, Thermometers and Thermobarometers in Granitic Systems, Rev. Min. Geochem., 69, 121-142.

Jiskoot, Courtney; Mutch, Euan; Cooper, Frances; Tattitch, Brian; Matjuschkin, Vladimir; Blundy, Jon

2014-05-01

128

Groundwater evolution of the granite area, Korea  

International Nuclear Information System (INIS)

The geochemistry and environmental isotopes of groundwater in the Cretaceous granite of the Yeongcheon area has been investigated. The hydrochemistry of groundwater belongs to the Ca-HCO_3 type. The oxygen-18 and deuterium data are clustered along the meteoric water line, indicating that the groundwater is of meteoric water origin. Tritium data show that the groundwaters were mostly recharged before pre-thermonuclear period and have been mixed with younger surface water flowing rapidly along fractured zones. Based on the mass balance and reaction simulation approaches using both the hydrochemistry of groundwater and the secondary mineralogy of fracture-filling materials, the low-temperature hydrogeochemical evolution of groundwater in the area has been modeled. The results of geochemical simulation show that the concentrations of Ca, Na and HCO_3 and pH of waters increase progressively owing to the dissolution of reactive minerals in flow paths. The concentrations of Mg and K first increase with the dissolution of reactant minerals, but later decrease when montmorillonite and illitic material are precipitated respectively. The continuous adding of reactive minerals, i. e. the progressively larger degrees of water/rock interaction, causes the formation of secondary minerals with the following sequence: hematite > gibbsite > kaolinite > montmorillonite > illitic material > microcline. The results of reaction simulation agree well with the observed water chemistry and secondary mineralogy, indicating the successful applicability of this simulation technique to delineate the complex hydrogeochemistry of bedrock groundwaters. (author)

2001-02-01

129

Younger Adults Hit Hardest This Flu Season  

Science.gov (United States)

... on this page, please enable JavaScript. Younger Adults Hit Hardest This Flu Season Although H1N1 strain predominates, ... aren't yet available. As in 2009, H1N1 hit younger adults harder than the elderly. Of the ...

130

MORPHOMETRY OF ZIRCON FROM BETLIAR GRANITE  

Directory of Open Access Journals (Sweden)

Full Text Available Morphometrical analyse has been provided, using the method of [10] , on zircon from granite porphyry at Betliar. The result of this investigation indicate a comagmatic origin of Betliar and other granite bodies in the Gemericum. The source materila for at the granite magma formation originated by hybridization of crust-mantle rocks.

Jakabská Katarína

1997-10-01

131

Intrusion detection sensor testing tools  

Energy Technology Data Exchange (ETDEWEB)

Intrusion detection sensors must be frequently tested to verify that they are operational, and they must be periodically tested to verify that they are functioning at required performance levels. Concerns involving this testing can include: The significant amount of manpower required, inconsistent results due to variability in methods and personnel, exposure of personnel to hazardous environments, and difficulty in obtaining access to the areas containing some of the intrusion sensors. To address these concerns, the Department of Energy directed Sandia National Labs. to develop intrusion detection sensor testing tools. Over the past two years Sandia has developed several sensor testing tool prototypes. This paper describes the evolution of an exterior intrusion detection sensor tester and automatic data logger, and also describes various interior intrusion detection sensor test fixtures that can be remotely activated to simulate an intruder.

Hayward, D.R.

1994-08-01

132

Geochronological and geological studies on a granite of higher Himalaya, North-East of Manikaran, Himachal Pradesh  

International Nuclear Information System (INIS)

Rb-Sr whole-rock data is presented for a biotite-granite of Central Crystallines. The whole-rock isochron age is found to be 467 +- 45 m.y. This should represent the time of intrusion of the granite. A brief account of the geology and petrography is also presented. The age of the biotite is found to be 8.8 +- 2.0 m.y., which is the youngest Rb-Sr age reported so far for a mineral from the Himalaya. This fixes the period when the rocks of this area, after being heated and uplifted, cooled to a temperature of about 3000C. (author)

1979-02-01

133

A long-lived mid-crustal magma chamber beneath a ring intrusion  

Science.gov (United States)

The Åva ring intrusion is one of four post-collisional shoshonitic ring intrusions situated in the archipelago of SW Finland. The Åva ring intrusion is about 7 km in diameter, and contains hundreds of ring dykes varying in width between 10 cm and 5 meters. These consist principally of coarse K-feldspar-phenocrystic granite, mingled in places with even-grained monzonite, although some of the rings consist of even-grained granites. The whole ring structure is cut by lamprophyric and granitic radial dykes. One of these phenocrystic granite radial dykes is found more than 8 km from the ring center. The ring rocks form a shoshonitic rock series with SiO2 contents between 45 and 78 wt-%. All rocks have elevated concentrations of Ba, Sr and LILE, while the even-grained granite has the highest Rb content of all rocks. Brittle emplacement structures in the country rocks can be traced around the whole ring intrusion, in places filled with granitic melts. The country rock also forms a dome structure into which the ring dykes intruded, consisting of reactivated gneisses and palingenic granites with ages overlapping those of the ring rocks. Texturally controlled PT and age determinations from the phenocrystic granite, the monzonite and the lamprophyres have shown that a mineral assemblage, including the K-feldspar phenocrysts, formed in a differentiating mid-crustal magma chamber (4 - 7 kbar) some 30-35 m.y. before emplacement in the upper crust. The deep mineral assemblages started to crystallise at ~1800 Ma, while emplacement in the upper crust occurred at ~1766 Ma (Eklund & Shebanov, 2005). Zircons from the even grained granite have bright CL-cores, either sharply or gradually grading to CL-dark rims. Some grains contain textural evidence of partial resorption on some crystal faces, however oscillatory zoning patterns consistently indicate (semi-)continuous crystallisation under evolving conditions. A new laser-ICP-MS survey of these zircons shows a spread of 207Pb/206Pb ages from 1808 Ma to as little as 1717 Ma. Results indicate a continuous period of crystallisation within a differentiating mid-crustal magma chamber for a period of at least 40 m.y. Crystal growth continued (semi-)continuously until magma emplacement in the upper crust. The youngest of these ages deviate slightly from discordia, which likely is a result of post-emplacement lead loss from zircon rims. New structural and age data and re-interpretation of the geometry of the ring-intrusion give a complementary version of the history of the Åva ring intrusion. The plastic structures with palingenic melts in the country rock surrounding Åva were formed by doming of the country rock above a slowly ascending, fractionating magma chamber containing a large amount of volatiles. When the volatile saturation was reached, due to cooling and decompression, the fluid pressure in the magma chamber caused a forceful emplacement in the upper crust forming the ring structure and the brittle deformation in the pre-existing dome.

Woodard, J.; Eklund, O.; Andersen, T.

2012-04-01

134

Molybdenum isotopes in granitic rocks  

Science.gov (United States)

Over the last decade, molybdenum (Mo) isotopes have been intensively studied to determine ocean (paleo-)redox conditions. However, gaps in our knowledge of the global Mo isotope budgets remain. As a ubiquitous constituent of the upper continental crust, granitoid rocks presents a significant terrestrial reservoir for Mo. Very little is known about the Mo isotopic composition and systematics of granitoid rocks. This study aims to constrain the Mo isotope composition of this important Mo reservoir and to determine the processes controlling it. A representative suite of well-characterized Phanerozoic I-, S-type granitoid samples from Australia was analysed for this purpose1. S-type granites show a significantly wider range Mo isotope compositions (-0.04 to 0.31permil) than I-type granites (0.13 to 0.35permil) on ?98/95Mo (+-Hekla volcano (Iceland) - covering basalts, andesites, dacites and rhyolites sequentially developed from differentiation in a magma chamber - were analysed. All Hekla samples have identical Mo isotope compositions within error (-0.08±0.1‰ to +0.02±0.1‰) and show no correlation with silica content3. This indicates that resolvable fractionation of Mo isotopes during magmatic differentiation is unlikely (although it cannot be ruled out for other settings). Provided the processes of magmatic differentiation contribute insignificant effects to Mo isotopes, granites formed by melting of or assimilation of a sedimentary source could preserve their Mo isotopic signature and thus differ from those derived from purely igneous sources. The observed diversity of ?98/95Mo in S-type granites, therefore, might indicate variation in the (sedimentary) sources of S-type granites. 1Chappell B. W. and White A. J. R. (2001) Aust. J.Earth Sci. 48, 489-500. 2Siebert et al. (2001) Geochemistry, Geophysics, Geosystems 2, 2000GC000124. 3Savage, P. et al. (2011) GCA 75, 6124-6139.

Yang, J.; Siebert, C.; Liang, Y.; Halliday, A.

2012-12-01

135

Emanation of radon from household granite.  

Science.gov (United States)

Emanation of radon (222Rn) from granite used for countertops and mantels was measured with continuous and integrating radon monitors. Each of the 24 granite samples emitted a measurable amount of radon. Of the two analytical methods that utilized electret-based detectors, one measured the flux of radon from the granite surfaces, and the other one measured radon levels in a glass jar containing granite cores. Additional methods that were applied utilized alpha-scintillation cells and a continuous radon monitor. Measured radon flux from the granites ranged from 2 to 310 mBq m-2 s-1, with most granites emitting <20 mBq m-2 s-1. Emanation of radon from granites encapsulated in airtight containers produced equilibrium concentrations ranging from <0.01 to 11 Bq kg-1 when alpha-scintillation cells were used, and from <0.01 to 4.0 Bq kg-1 when the continuous radon monitor was used. PMID:19276708

Kitto, Michael E; Haines, Douglas K; Arauzo, Hernando Diaz

2009-04-01

136

Network Intrusion Forensic Analysis Using Intrusion Detection System  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The need for computer intrusion forensics arises from the alarming increase in the number of computer crimes that are committed annually. After a computer system has been breached and an intrusion has been detected, there is a need for a computer forensics investigation to follow. Computer forensics is used to bring to justice, those responsible for conducting attacks on computer systems throughout the world. Because of this the law must be follow precisely when conducting a forensics investi...

2011-01-01

137

Geology and geochemistry of the Redrock Granite and anorthosite xenoliths (Proterozoic in the northern Burro Mountains, Grant County, New Mexico, USA  

Directory of Open Access Journals (Sweden)

Full Text Available Mineral ages from the A-type granites and anorthosite xenoliths in the Redrock area in the northwestern Burro Mountains in southwestern New Mexico cluster around ~1220–1225 Ma and provide yet another example of bimodal igneous activity during this time period in the southwestern United States. The metaluminous to peraluminous, marginally alkaline to subalkaline Redrock Granite exhibits the textural, mineralogical, and geochemical features of A-type granitethat was emplaced at a relatively high crustal level. Field relationships, whole rock and mineral geochemical and isotopic trends suggest that the four phases of the Redrock Granite are genetically related, with the miarolitic biotite/alkali feldspar granite being the youngest phase. Spatial relationships and geochemical data suggest that the anorthosite xenoliths were coeval with the RedrockGranite, which is consistent with the anorthosite being derived from the upper mantle, possibly due to deep mantle upwellings, and the Redrock Granite from the lower crust. The process involved melting in the upper mantle, emplacement of anorthosite in the crust resulting in partial crustal melting and thinning, and, finally, intrusion of shallow silicic plutons, the Redrock Granite. The Redrock Granite and anorthosite were presumably derived from sources characterized by subtle, long-term LREE depletion, with ?Nd (at 1220 Ma values on theorder of +1 to +2.

Virginia T. McLemore

2002-01-01

138

Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites  

International Nuclear Information System (INIS)

Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR

1987-01-01

139

Southern complex: geology, geochemistry, mineralogy, and mineral chemistry of selected uranium- and thorium-rich granites  

Energy Technology Data Exchange (ETDEWEB)

Four major rock groups are defined in the Southern Complex: the Bell Creek Granite (BCG), the Clotted Granitoids (CGR), the Albite Granite (AGR), and the Migmatite Complex. Metatexites of the Migmatite Complex are the oldest rocks and include paleosome of a metasedimentary and metavolcanic protolith represented by Banded Iron Formation, Banded Amphibolite, and Banded Gneisses, and interlayered or crosscutting leucogranites. The CGR span the range from metatexite to diatexite and represent in-situ partial melting of metapelitic layers in the protolith during intrusion of the BCG. The BCG cuts the migmatites, is locally cut by the CGR, and was derived by partial melting of a dominantly metasedimentary protolith at some depth below the presently exposed migmatites during a regional tectonothermal event. The Albite Granite is a 2km diameter, muscovite-fluorite-columbite-bearing intrusive stock that cuts all other major units. The thorium history of the BCG is a function of the history of monazite. The thorium history of the CGR is also dominated by monazite but the thorium content of this unit cannot be entirely accounted for by original restite monazite. The uranium history of the BCG and CGR was dominated by magmatic differentiation and post magmatic, metamorphic and supergene redistributions and is largely independent of the thorium history. The thorium and uranium history of the AGR was dominated by magmatic/deuteric processes unlike the BCG and CGR.

Hoffman, M.A.

1987-01-01

140

Localisation of deformation in the thermal contrast at a granite batholith margin, New Zealand  

Science.gov (United States)

The Wainui Shear Zone is a ? 1.2 km wide steeply dipping ductile shear zone that is intimately associated with the western margin of a very extensive granite batholith in central New Zealand. Shear sense indicators and lineation orientations within the central high-strain portion of shear zone consistently show a reverse dip-slip east-side-up sense of motion. Shallower foliation in the margins of the shear zone is interpreted to pre-date the central high-strain zone. However, U-Pb and Ar-Ar data reveal that all ductile deformation occurred between ?114 and 109 Ma (and probably between 114 and 111 Ma) requiring: (1) that deformation kinematics within the shear zone changed over a short time period, and (2) the shear fabrics formed immediately after emplacement of the voluminous granite batholith. The temporal and spatial link between the deformation and plutonism is hypothesised to be a result of thermal weakening of the cooler Paleozoic crust by Cretaceous granite intrusion, which promoted localisation of deformation onto the intrusive contact. Deformation was initially distributed over a wide zone but became focused into a central mylonite zone. Continental-scale shortening is recorded as a network of ductile shear zones that formed on thermal contrasts within the upper, middle and lower crust along the New Zealand Gondwana margin.

Scott, J. M.; Borcovsky, D. A.; Palin, J. M.; Toy, V. G.

2014-07-01

 
 
 
 
141

Relations of zoned pegmatites to other pegmatites, granite, and metamorphic rocks in the southern Black Hills, South Dakota  

Science.gov (United States)

The pegmatite field and the Harney Peak Granite of the southern Black Hills, South Dakota, form an igneous system that progresses from slightly biotitic muscovite granite through layered pegmatitic granite, with alternating sodic and potassic rocks, to simple plagioclase-quartz-perthite pegmatites, and on to zoned pegmatites. Most of the country rocks are Lower Proterozoic mica schists. At 1700 Ga, intrusion of the Harney Peak Granite created a large dome in these rocks, a thermal aureole with a staurolite, a first sillimanite isograd, and a small area of metamorphism above the second sillimanite isograd. The zoned pegmatites have a strong tendency to occur in clusters, and the types of pegmatites are different in different clusters. A less obvious tendency is a regional zonation in which rare-mineral pegmatites become more abundant and muscovite pegmatites less abundant toward the outskirts of the region. The composition of the granite indicates that its magma originated by partial melting of metasedimentary mica schists similar to those at the present surface. The pegmatitic nature of most of the granite probably reflects exsolution of an aqueous phase. -from Authors

Norton, J. J.; Redden, J. A.

1990-01-01

142

Jakob Granit | Staff at SEI  

... & Birkman, J. (Eds.), Coping with Global Environmental Change, Disaster and Security. Threats, Challenges, Vulnerabilities and Risks. Hexagon Series on Human and Environmental Security and Peace (HESP Vol. 5). Berlin, Heidelberg, New York: Springer-Verlag. Granit. J. & Lindström. A. (2011). Constraints and Opportunities in Meeting the Increasing Use of Water for Energy Production. In Proceedings of the ESF Strategic Workshop on Accounting for water scarcity and pollution in ...

143

Intrusion Detection A Machine Learning Approach  

CERN Multimedia

This important book introduces the concept of intrusion detection, discusses various approaches for intrusion detection systems (IDS), and presents the architecture and implementation of IDS. It emphasizes on the prediction and learning algorithms for intrusion detection and highlights techniques for intrusion detection of wired computer networks and wireless sensor networks. The performance comparison of various IDS via simulation will also be included.

Tsai, Jeffrey JP

2011-01-01

144

Human intrusion in geologic disposal  

International Nuclear Information System (INIS)

This report discusses the possibility of human intrusion into the WIPP facility, an undergound disposal facility for alpha-bearing wastes. The probability of exploratory drilling occurring at the site is described

1993-11-14

145

Human intrusion in geologic disposal  

Energy Technology Data Exchange (ETDEWEB)

This report discusses the possibility of human intrusion into the WIPP facility, an undergound disposal facility for alpha-bearing wastes. The probability of exploratory drilling occurring at the site is described.

1993-12-31

146

INTRUSION DETECTION ON CLOUD APPLICATIONS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cloud computing has grown from being a promising business concept to one of the fastestgrowing segments of the IT industry. So, cloud environment always remains vulnerable to attacks. Theframework serves as an excellent platform for making cloud services intrusion tolerant. The feasibility of theframework has been tested by making cloud’s Infrastructure as a Service (IaaS) and Data Storage Serviceintrusion tolerant. The proposed framework has been validated by integratingIntrusion Tolerance...

2013-01-01

147

FIPS: FIRST Intrusion Prevention System  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intrusion Prevention Systems try to actively disarm attacks on computer systems and networks. In this work, we introduce the network based FIRST Intrusion Prevention System (FIPS) which is capable of detecting novel attacks and contain them effectively. This inline device operates by redirecting anomalous packets to a specially hardened shadow system or logging them to a so-called forensic sink for further examination. Both the offline and real life evaluation of the implementation shows that...

2010-01-01

148

Extra-terrestrial igneous granites and related rocks: A review of their occurrence and petrogenesis  

Science.gov (United States)

The telluric planets and the asteroid belt display the same internal structure with a metallic inner core and a silicate outer shell. Experimental data and petrological evidence in silicate systems show that granite can be produced by extreme igneous differentiation through various types of igneous processes. On Moon, 4.4-3.9 Ga granite clasts display dry mineral assemblages. They correspond to at least 8 discrete intrusive events. Large K/Ca enrichment and low REE abundances in granite relative to KREEP are consistent with silicate liquid immiscibility, a process observed in melt inclusions within olivine of lunar basalts and in lunar meteorites. Steep-sided domes identified by remote sensing can represent intrusive or extrusive felsic formations. On Mars, black-and-white rhythmic layers observed on the Tharsis rise along the flanks of the peripheral scarps of the Tharsis Montes giant volcanoes suggest the possible eruption of felsic pyroclastites. Though no true granites were found so far in the Martian SNC meteorites, felsic glasses and mesostases were identified and a component close to terrestrial continental (granitic) crust is inferred from trace element and isotope systematics. Venus has suffered extensive volcanic resurfacing, whereas folded and faulted areas resemble terrestrial continents. Near large shield volcanoes, with dominant basaltic compositions, steep-sided domes have been interpreted as non-degassed silicic extrusions. The hypothesis of a granitic component is "tantalising". Extra-terrestrial granite is frequently found as clasts and mesostases in asteroidal meteorites. Porphyritic textures, with alkali feldspar crystals up to several centimetres in size, were observed in silicate enclaves within iron meteorites. In the chondrite clan, polymict breccias can contain granitic clasts, whose provenance is debated. One clast from the Adzhi-Bogdo meteorite yields a 4.53 ± 0.03 Ga Pb-Pb age, making it the oldest known granite in the solar system. The vast majority of granitic materials recognised so far in the extra-terrestrial record are characterised by ferroan A-type compositions, characterised by high to very high K2O and medium CaO contents, sodic varieties being exceedingly rare. Textural evidence of graphic quartz-alkali feldspar intergrowths within crystallised products suggests that they are igneous in origin and crystallised quickly from a liquid. In water-depleted to water-free environments, fluorine and chlorine can play significant roles, as their effects on liquidus temperatures and crystallising assemblages are nearly identical to those of water. The distribution of alkalis and alkaline earths cannot be related only to extensive crystal fractionation, but is likely induced by supplementary silicate liquid immiscibility. Medium-temperature silicate liquid immiscibility is well known as a mode of differentiation in experimental petrology studies at very low pressures on systems dominated by Fe, Ti, K, and P as major elements. The ultimate question is, therefore, not whether granite (s.l.) occurs in any given planetary body, but if sufficient volumes of granitic materials could have been produced to constitute stable continental nuclei.

Bonin, Bernard

2012-11-01

149

Natural radionuclide distribution in Brazilian commercial granites  

International Nuclear Information System (INIS)

The dimension stones sector in Brazil produces several varieties of granites, marbles, slates and basalts. More than half of this production corresponds to around 200 different commercial types of granites with specific names, geographical and geological origins and mineral compositions. The well-known natural radioactivity present in rocks, where high radiation levels are associated with igneous rocks such as granite, can be used to determine their general petrologic features. This subject is important in environmental radiological protection, since granites are widely used as building and ornamental stones. In this paper, it is applied to correlate the petrographic characteristics of commercial granites with their corresponding dose rates for natural radioactivity. Amounts of thorium, uranium and potassium concentrations have been reported in several Brazilian commercial granite samples

2005-06-01

150

A strontium isotope study on the Neu granitic pluton and its mafic inclusion, San'in zone, Southwest Japan  

International Nuclear Information System (INIS)

The mafic inclusions and the host granites of the Neu granitic pluton were studied mainly from a view point of Sr isotopes. All of the analysed data are plotted on a definite isochron, yielding as age of 65.0 +- 0.3 Ma with an initial ratio of 0.70475 +- 0.00001. The Neu pluton has the lowest initial ratio among Cretaceous to Paleogene intrusive rocks in the San'in zone, which usually have the ratios lower than 0.706. The result is consistent with an interpretation that the magma for the Neu pluton was derived from upper mantle or lower crust without much contamination with the upper crustal materials. A cognate origin for the granite and the mafic inclusion is suggested by geological, petrographical and isotopic evidences. (author)

1984-01-01

151

Strontium isotope study on the Neu granitic pluton and its mafic inclusion, San'in zone, Southwest Japan  

Energy Technology Data Exchange (ETDEWEB)

The mafic inclusions and the host granites of the Neu granitic pluton were studied mainly from a viewpoint of Sr isotopes. All of the analysed data are plotted on a definite isochron, yielding as age of 65.0 +- 0.3 Ma with an initial ratio of 0.70475 +- 0.00001. The Neu pluton has the lowest initial ratio among Cretaceous to Paleogene intrusive rocks in the San'in zone, which usually have the ratios lower than 0.706. The result is consistent with an interpretation that the magma for the Neu pluton was derived from upper mantle or lower crust without much contamination with the upper crustal materials. A cognate origin for the granite and the mafic inclusion is suggested by geological, petrographical and isotopic evidences.

Iizumi, Shigeru; Mishima, Hozumi (Shimane Univ., Matsue (Japan)); Okamoto, Yasunari; Honma, Hiroji

1984-03-01

152

Granite Sludge Reuse in Mortar and Concrete  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The disposal of solid wastes produced in granite industry to the environment without any treatment cause not only economical but also serious environmental problems. In this study Granite Powder (GP) which produced as solid waste from the cutting and polishing of granite rocks was reused as additive to mortar and concrete cement. Incorporation of GP in mortar and concrete in ratios of 10, 20, 30 wt.% improved mortar and concrete compressive strengths and the concrete workability. The experime...

Al- Hamaiedeh, Husam D.; Khushefati, Waleed H.

2013-01-01

153

Age of granites of Wrangel Island metamorphic complex  

Science.gov (United States)

Within huge arctic shelf of Eastern-Siberian and Chukchi seas the metamorphic basement (Wrangel complex, Berri Formation) is exposed only on the Wrangel Island. There are different points of views on the age of metamorphic rocks of Wrangel complex (Berri Formation): (1) Neoproterozoic (Kameneva, 1970; Ageev, 1979; Kos'ko et al., 1993, 2003), (2) Devonian (Til'man et al., 1964, 1970; Ganelin, 1989). Metamorphic basement is represented by stratified complex, composed of dislocated metavolcanic, metavolcaniclastic and metasedimentary rocks (schists, metasandstones, metaconglomerated) with single lenses and layers of carbonate rocks (Wrangel Island…, 2003). Among basement rocks in the central part of Wrangel Island there are felsic intrusive bodies. They form small tabular bodies from tens centimeters to 70-80 meters in thickness, rarely dikes and small stocks (up to 20 x 30 m) and are composed of granite-porphyres, rarely muscovite porphyr-like granites and granosyenites (Wrangel Island…, 2003). The age of intrusions allow to determine the age of basement formation. Earlier the age of intrusions was determined by different methods and correlated to the boundary between Neoproterozoic and Paleozoic: K-Ar 570-603 Ma, Pb-Pb 590±50 Ma (S.M. Pavlov, Institute of Precambrian Geology and Geochronology, USSR Academy of Sciences), Rb-Sr 475±31 Ma (I.M.Vasil'eva, Institute of Precambrian Geology and Geochronology, USSR Academy of Sciences), U-Pb 609, 633, 677 Ma (Geological Survey of Canada) (Wrangel Island…, 2003; Kos'ko et al., 1993; Cecile et al., 1991). In the lower part of metamorphic rocks of Wrangel complex there are conformable tabular bodies of gneissosed and foliated granitoides. The latter are meramorphosed and transformed in biotite-muscovite-feldspar-quartz-sericite and muscovite-feldspar-quartz-sericite gneisses and schists, where relics of primary minerals (quartz, plagioclase, potassium feldspar, rarely biotite and muscovite) and equigranular granitic texture are preserved. Accessory minerals of granitoides are zircon, sphene, apatite. During field work of 2006 year the probes for U-Pb SHRIMP zircon datings were collected (upper reaches of Khishchnikov River). Dating was carried out on SHRIMP-II in the Center of Isotopic Studies of Federal State Unitary Enterprize "A.P.Karpinsky Russian Geological Research Institute". Wheited mean ages of zircons from three probes are: 702±3 Ma (N=19), 701±7 Ma (N=3), 707±4 Ma (N=25). They indicate Neoproterozoic age of granitoides. Furthermore, some zircons contain inherited cores, for which following datings were obtained: 1.1; 1,21; 1.107; 1.2-1,4; 1.58; 1.8; 2.6 Ga. These data allow supposing the presence of ancient (Neoproterozoic-Mesoproterozoic) rocks in the basement of Wrangel Island and their participation in the melting process during granite magmas formation. The work was supported by Russian Fund of Basic Researhes projects 13-05-00249, 14-05-00031, Scientific school NSh-2981.2014.5.

Luchitskaya, Marina; Sergeev, Sergey; Sokolov, Sergey; Tuchkova, Marianna

2014-05-01

154

Geochemistry and petrogenesis of the proterozoic granites from Jhabua and Dhar districts, Madhya Pradesh, India and their bearing on uranium mineralisation  

International Nuclear Information System (INIS)

In the western part of Madhya Pradesh a number of small plutonic granites occur as intrusive into the gneisses and Aravalli metasediments. Granites are of grey, pink colour and gneissic varieties. Mineralogically, the granites are two mica bearing. Chemically they are K2O rich, calc-alkaline, metaluminous to peraluminous and differentiated in nature. Tectonically they are volcanic arc types with an affinity to syn-collisional setup. Basement reactivation may be the cause of the emplacement of these granites as the area is traversed by a number of basement lineaments. They are enriched in light REE with Ce/Yb ratio ranging from 1.4 to 8.4. Negative Eu anomaly (Eu/Eu* 0.2 to 0.8) suggests that they are fractionated. High Th/U ratio (1-18) indicates that uranium has been leached out. Hence the overlying infratrappeans hold potential for litho/structural controlled uranium mineralisation.(author)

2004-12-01

155

Geology and mineralization of the Jabalat alkali-feldspar granite, northern Asir region, Kingdom of Saudi Arabia  

Science.gov (United States)

The Jabalat post-tectonic granite pluton is composed of albite- and oligoclase-bearing, low-calcium, F-, Sn- and Rb-rich subsolvus granites. These granites display evidence of late-magmatic, granitophile- and metallic-element specialization, resulting ultimately in the development of post-magmatic, metalliferous hydrothermal systems characterized by a Mo sbnd Sn sbnd Cu sbnd Pb sbnd Zn sbnd Bi sbnd Ag sbnd F signature. Two main types of mineralization are present within the pluton and its environs: (1) weakly mineralized felsic and aplitic dikes and veins enhanced in Mo, Bi, Ag, Pb and Cu; and (2) pyrite—molybdenite—chalcopyrite-bearing quartz and quartz—feldspar veins rich in Mo, Sn, Bi, Cu, Zn and Ag. A satellite stock, 3 km north of the main intrusion, is composed of fine-grained, miarolitic, muscovite—albite—microcline (microperthite) granite. The flanks of this intrusion and adjacent dioritic rocks are greisenized and highly enriched in Sn, Bi and Ag. Quartz veins which transect the satellite stock contain molybdenite and stannite.

Al Tayyar, Jaffar; Jackson, Norman J.; Al-Yazidi, Saeed

156

IGSC perspective on human intrusion  

International Nuclear Information System (INIS)

Hiroyuki Umeki, Chairman of the IGSC, indicated that when updating its programme of work, in 2007, the IGSC raised a number of issues that the group recommended RWMC-RF to consider for further discussion. The conclusions from different IGSC studies were that there is agreement at a conceptual level on the treatment of human intrusion, but a range of approaches are adopted for addressing it in safety assessment, and the degree to which these are specified in regulations also varies considerably among national programmes. The requirements and constraints for considering human intrusion are stylised and, therefore, are largely specified in regulations; in many national programmes, relatively few (or no) aspects are left to the discretion of the implementer. Human intrusion is considered as a sensitive issue for many programmes since it can be an issue of high interest to stakeholders and decisions on approaches are normally undertaken after extensive consultation; those who have already taken decisions are generally satisfied with the outcome and would not welcome work that might undermine or re-open the issue. Thus, a detailed re-examination of safety assessment of human intrusion and of the conclusions that have been reached previously is not a priority. This issue remains of interest to IGSC, however, as it must be addressed in some fashion within all safety cases. The key questions are: - Should regulations require measures to reduce the likelihood or consequences of human intrusion? What 'credit' can be taken for such measures? Is there new thinking or methods in terms of memory and markers? - What types of stylised human intrusion should be considered in a safety case? What are the roles of the regulator and implementer in doing so? - What consequences should be considered? What are the protection criteria against which to assess human intrusion scenarios? - Are the answers to any of these questions site-, culture-, concept- or waste-specific? A concluding question may be: Is there still consensus on the areas of agreement, or has thinking evolved?

2009-01-20

157

Contrasting Structures and Deformational History of Syntectonic Granites of Campina Grande and Serra Redonda, Borborema Province, NE Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available The Campina Grande and Serra Redonda Granites are intrusive along the contact of the Paleoproterozoic basement(Alto Moxotó Domain with the Tonian gneisses (Alto Pajeú Domain of the Borborema Province (northeast Brazil. TheCampina Grande Granite (U-Pb age = 581± 2 Ma shows a concentric oval-shaped structure whereas the Serra RedondaGranite (U-Pb age = 576 ± 3 Ma has a tabular shape, elongated in the NE-SW direction. The plutons are separated bythe left-lateral Galante transcurrent shear zone. In this study, the anisotropy of magnetic susceptibility (AMS was appliedto 64 outcrops of granites to determine the internal structures of these plutons and to explore the relationship betweenmagmatism and deformation in an orogenic setting. The magnetic fabrics are concordant with the metamorphic structure ofthe host rocks. Strike-slip shear zones controlled the emplacement of the Serra Redonda Granite, as indicated by sigmoidalfoliation, defining shear bands associated with the Galante shear zone. In contrast, the magmatic/magnetic fabric of theCampina Grande granite seems to have been produced by body (ascensional forces. The pluton displays an inward dipping, concentric planar fabric parallel to the wall rock contact and lineations highly oblique to the foliation trend. The fabric of the Campina Grande pluton is consistent with a magma moving over a ramp dipping to southwest, with the lineation at high angle to the NE-trending flow direction. The contrasting structures of the plutons reflect the episodic nature of orogenic deformation, which was punctuated by the alternation of weak and strong strains, affecting the fabric development of the syntectonic intrusions.

Sérgio Wilians de Oliveira Rodrigues

2011-04-01

158

Rb-Sr age of Godhra and related granites, Gujrat, India  

International Nuclear Information System (INIS)

Rubidium and strontium determinations are reported for Godhra and geographically related granites from central Gujarat. The whole rock data define a Rb-Sr isochron corresponding to a common age of 955 +- 2O m.y. and initial Sr ratio of 0.7130 +- 0.0O1. This age is distinctly older than the age of 735 m.y. reported for the Erinpura suite of rocks from Mount Abu in western Rajasthan and from Idar in nothern Gujarat. There are at least two generations of post-Delhi intrusive rocks in the Gujarat precambrian. Boitites associated with these granites have the same age as the whole-rocks within experimental error indicating the absence of significant metamorphic heating since the time of emplacement. It is significant that rocks of similar age occur in the Rajasthan Precambrian mainly in the axial zone of the Aravalli Mountains. (author)

1979-03-01

159

INTRUSION DETECTION ON CLOUD APPLICATIONS  

Directory of Open Access Journals (Sweden)

Full Text Available Cloud computing has grown from being a promising business concept to one of the fastestgrowing segments of the IT industry. So, cloud environment always remains vulnerable to attacks. Theframework serves as an excellent platform for making cloud services intrusion tolerant. The feasibility of theframework has been tested by making cloud’s Infrastructure as a Service (IaaS and Data Storage Serviceintrusion tolerant. The proposed framework has been validated by integratingIntrusion Tolerance via Threshold Cryptography (ITTC mechanism in the simulated cloud’s IaaS. For this,the data centre authentication key is distributed among the hosts using Shamir Secret Sharing algorithm.Performance of the new simulated service model is measured using various performance metrics such astotal execution time, intrusion detection time, recovery time, number of cloudlets etc. It involves, usingproposed Cloud Intrusion Tolerance framework for securing cloud Data Storage. The correctness of user’sdata is ensured by using erasure-correcting code in the file distribution preparation to provide redundancyparity vectors. Performance analysis using erasure-correcting code for securing data storage is also done. Weare also implementing the different networks such as SHIM (System Health and Intrusion Monitoring isused as an exemplary host-based IDS to validate our approach, DRCP (Dynamic Registration andConfiguration Protocol is an auto configuration protocol in mobile AdHoc networks, OLSR (Optimized LinkState Routing protocol is a proactive, table-driven routing protocol in MANETs.

A. Venkat Reddy

2013-09-01

160

Gravity data inversion as a probe for the 3D shape at depth of granitic bodies  

International Nuclear Information System (INIS)

Granitic intrusions represent potential sites for waste disposal. A well constrained determination of their geometry at depth is of importance to evaluate possible leakage and seepage within the surroundings. Among geophysical techniques, gravity remains the best suited method to investigate the 3D shape of the granitic bodies at depth. During uranium exploration programmes, many plutons emplaced within different geochemical and tectonic environment have been surveyed. The quality of gravity surveying depends on the intrinsic accuracy of the measurements, and also on their density of coverage. A regularly spaced and dense coverage (about 1 point/km2) of measurements over the whole pluton and its nearby surroundings is needed to represent the gravity effect of density variations. This yields a lateral resolution of about 0.5 kilometer, or less depending on depth and roughness of the floor, for the interpretation of the Bouguer anomaly map. We recommend the use of a 3D iterative method of data inversion, simpler to run when the geometry and distribution of the sources are already constrained by surface data. This method must take into account the various density changes within the granite and its surroundings, as well as the regional effect of deep regional sources. A total error in the input data (measurements, densities, regional field) is estimated at 6%. We estimate that the total uncertainty on the calculated depth values does not exceed ± 15%. Because of good coverage of gravity measurements, the overall shape of the pluton is certainly better constrained than the depth values themselves. We present several examples of gravity data inversion over granitic intrusions displaying various 3D morphologies. At a smaller scale mineralizations are also observed above or close to the root zones. Those examples demonstrate the adequacy of joint studies in constraining the mode of magma emplacement before further studies focussing to environmental problems. 59 refs, 9 figs

1995-10-01

 
 
 
 
161

Integration of remote sensing data and ground data as an aid to exploration for granite related mineralization, Salamanca Province, W Spain  

International Nuclear Information System (INIS)

This paper reports that the major geological features associated with the Los Santos tungsten skarn are: vicinity of the intrusive granite contact: geochemical zoning within the granite; anomalous width of the contact aureole; presence of fault zones; development of limonitic soil; presence of limestone horizons. Digital image processing techniques are applied to recognize and enhance these features in satellite images and airborne geophysical datasets. In satellite images the granites are textually distinct from other terrains, due to a higher degree of variation between adjoining pixels and a higher density of lineaments. Supervised classification of TM-bands 3,4,5 and 7 allows discrimination of granite and regional metamorphic terrain, while contact-metamorphic and limonitic soils are classified better using bands 1,3,4 and 7. Airborne magnetometry discriminates well between granites and sediments. The magnetization of the sedimentary rocks in the contact aureole is reset due to thermal and chemical overprinting. This is visible in the magnetic image. Large faults are detected. Radiometric data allow distinction between granite and sediments and recognition of the geochemical zoning within the granite

1991-05-02

162

Intrusion Detection using unsupervised learning  

Directory of Open Access Journals (Sweden)

Full Text Available Clustering is the one of the efficient datamining techniques for intrusion detection. In clustering algorithm kmean clustering is widely used for intrusion detection. Because it gives efficient results incase of huge datasets. But sometime kmean clustering fails to give best result because of class dominance problem and no class problem. So for removing these problems we are proposing two new algorithms for cluster to class assignment. According to our experimental results the proposed algorithm are having high precision and recall for low class instances.

Kusum bharti

2010-08-01

163

P-T path fluid evolution in the Gross Spitzkoppe granite stock, Namibia  

Directory of Open Access Journals (Sweden)

Full Text Available The Gross Spitzkoppe granite stock (GSS is a zoned 30 km^2 epizonal intrusion that consists of three main granites: 1 medium-grained biotite granite (marginal, 2 a coarse-grained biotite granite, and 3 a central, porphyritic granite. The stock contains pegmatites as banded marginal stockscheiders and isolated pockets composed of large alkali feldspar and quartz, dark mica, interstitial fluorite, and euhedral topaz and beryl crystals. In the porphyritic granite there are local wolframite-bearing greisens and hydrothermal fluorite and topaz-rich veins.Fluid inclusion studies were conducted on: 1 topaz and quartz crystals from the marginal stockscheider; 2 quartz, topaz, fluorite and beryl crystals from isolated pegmatites; 3 topaz from a miarolitic pegmatite; 4 beryl and quartz veins from greisenized porphyritic granite; and 5 fluorite from a late fluorite vein inthe coarse-grained biotite granite. Preliminary data indicate the presence of three compositionally distinct primary and pseudosecondary inclusion types that are of late magmatic-hydrothermal origin.Type 1. Low salinity (0–10 eq. wt% NaCl H2O (± CO2 inclusions that homogenize to the liquid phase in the temperature range of 300 to 550?C. These inclusions are from quartz, topaz and beryl. Inclusions in fluorite from the fluorite vein homogenize at ~170?C and have a salinity of ca. 1–2 eq. wt% NaCl.Type 2. Saline (25–30 eq. wt% NaCl halite-bearing H2O (± CO2 inclusions that homogenize to the liquid phase in the temperature range of 300 to 400?C. These inclusions are from quartz.Type 3. Low salinity (0–3 eq. wt% NaCl H2O-CO2 inclusions that homogenize to vapor phase in the temperature range of 330 to 550?C. These inclusions are from quartz and topaz.Hydrothermal fluids from greisen minerals are represented by type 1 and type 2 H2O inclusions. They are predominantly of low salinity (~8 eq. wt% NaCl and homogenize to the liquid phase in the temperature range of 300 to 500?C. Isochores for contemporaneous type 2 and type 3 inclusions with homogenization temperature range of 330 to 400?C indicate a maximum trapping pressure of about 900 bar for the marginal stockscheider.

Stephen Frindt

2002-01-01

164

Category-Based Intrusion Detection Using PCA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Existing Intrusion Detection Systems (IDS) examine all the network features to detect intrusion or misuse patterns. In feature-based intrusion detection, some selected features may found to be redundant, useless or less important than the rest. This paper proposes a category-based selection of effective parameters for intrusion detection using Principal Components Analysis (PCA). In this paper, 32 basic features from TCP/IP header, and 116 derived features from TCP dump are selected in a netw...

Gholam Reza Zargar; Tania Baghaie

2012-01-01

165

VISUALIZATION TECHNIQUES FOR INTRUSION DETECTION – A SURVEY  

Directory of Open Access Journals (Sweden)

Full Text Available In traditional intrusion detection system (IDS environments, little activity has been applied to usingvisual analysis as an aid to intrusion detection. With more information systems being attacked and attacktechniques evolving, the task of detecting intrusions is becoming an increasingly difficult. Efficientinformation visualization is an important element required for urgent detection of intruders.This paper presents a survey on using visualization techniques in intrusion detection system.Finally authors proposed a framework for visualization system for ID.

Ibrahim Elhenawy

2011-09-01

166

Data Mining for Intrusion Detection  

Science.gov (United States)

Data Mining Techniques have been successfully applied in many different fields including marketing, manufacturing, fraud detection and network management. Over the past years there is a lot of interest in security technologies such as intrusion detection, cryptography, authentication and firewalls. This chapter discusses the application of Data Mining techniques to computer security. Conclusions are drawn and directions for future research are suggested.

Singhal, Anoop; Jajodia, Sushil

167

Final OSWER Vapor Intrusion Guidance  

Science.gov (United States)

EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

168

Rb-Sr age of Gaik granite, Ladakh Batholith, northwest Himalaya  

Energy Technology Data Exchange (ETDEWEB)

The Gaik Granite is a part of Ladakh batholith outcropping between Gaik and Kiari in NW Himalaya. This is a pink porphyritic granite rich in biotite and poor in hornblende. Rb-Sr analyses have been made on six whole-rock samples of the Gaik Granite. Though the samples are poorly enriched in radiogenic Sr, they define a reliable isochron corresponding to an age of 235+-13(2sigma) m.y. and initial /sup 87/Sr//sup 86/Sr ratio of 0.7081+-0.0004 (2sigma), Biotite, plagioclase and potash feldspar fractions separated from two of the samples have yielded a much younger mineral isochron at 30+-1.5 m.y. indicating a nearly complete redistribution of Sr isotopes between mineral phases at a time much later than the primary emplacement of the granite. The present results show that at least some components of the Ladakh batholith are of Permo-Triassic aqe. These rocks were isotopically re-equilibrated on a mineral scale during Upper Oligocene in response to the Himalayan orogeny.

Trivedi, J.R.; Gopalan, K. (Physical Research Lab., Ahmedabad (India)); Sharma, K.K.; Gupta, K.R.; Choubey, V.M. (Wadia Inst. of Himalayan Geology, Dehra Dun (India))

1982-03-01

169

Rb-Sr age of Gaik granite, Ladakh Batholith, northwest Himalaya  

International Nuclear Information System (INIS)

The Gaik Granite is a part of Ladakh batholith outcropping between Gaik and Kiari in NW Himalaya. This is a pink porphyritic granite rich in biotite and poor in hornblende. Rb-Sr analyses have been made on six whole-rock samples of the Gaik Granite. Though the samples are poorly enriched in radiogenic Sr, they define a reliable isochron corresponding to an age of 235+-13(2sigma) m.y. and initial 87Sr/86Sr ratio of 0.7081+-0.0004 (2sigma), Biotite, plagioclase and potash feldspar fractions separated from two of the samples have yielded a much younger mineral isochron at 30+-1.5 m.y. indicating a nearly complete redistribution of Sr isotopes between mineral phases at a time much later than the primary emplacement of the granite. The present results show that at least some components of the Ladakh batholith are of Permo-Triassic aqe. These rocks were isotopically re-equilibrated on a mineral scale during Upper Oligocene in response to the Himalayan orogeny. (author)

1982-01-01

170

Intrusion of orthographic knowledge on phoneme awareness: Strong in normal readers, weak in dyslexic readers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In three typical phonological awareness tasks it was found that children with normal reading development sometimes give responses that are based on orthographic rather than phonological information. In dyslexic children, the number of occurrences of such orthographic intrusions was significantly lower. This effect cannot be explained by positing a lower degree of orthographic knowledge in dyslexic children since a group of younger children who had the same spelling level as the dyslexics also...

Landerl, K.; Frith, U.; Wimmer, H.

1996-01-01

171

Meltwater routing and the Younger Dryas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Younger Dryas—the last major cold episode on Earth—is generally considered to have been triggered by a meltwater flood into the North Atlantic. The prevailing hypothesis, proposed by Broecker et al. [1989 Nature 341:318–321] more than two decades ago, suggests that an abrupt rerouting of Lake Agassiz overflow through the Great Lakes and St. Lawrence Valley inhibited deep water formation in the subpolar North Atlantic and weakened the strength of the Atlantic Meridional Overturning C...

Condron, Alan; Winsor, Peter

2012-01-01

172

A Younger Age for the Universe  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The age of the universe in the Big Bang model can be calculated from three parameters: Hubble's constant, h; the mass density of the universe, Omega_m; and the cosmological constant, Omega_lambda. Recent observations of the cosmic microwave background and six other cosmological measurements reduce the uncertainty in these three parameters, yielding an age for the universe of 13.4 +/- 1.6 billion years, which is a billion years younger than other recent age estimates. A diffe...

Lineweaver, Charles H.

1999-01-01

173

Framing Effects in Younger and Older Adults  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A growing literature on decision making in older adults suggests that they are more likely to use heuristic processing than are younger adults. We assessed this tendency in the context of a framing effect, a decision-making phenomenon whereby the language used to describe options greatly influences the decision maker’s choice. We compared decision making under a standard (“heuristic”) condition and also under a “justification” condition known to reduce reliance on heuristics. In the...

Kim, Sunghan; Goldstein, David; Hasher, Lynn; Zacks, Rose T.

2005-01-01

174

Granite emplacement during contemporary shortening and normal faulting: structural and magnetic study of the Veiga Massif (NW Spain)  

Science.gov (United States)

The Veiga Massif belongs to the calc-alkaline series of Hercynian granitic rocks of the Ibero-Armorican arc The Veiga granodiorite intruded during the Upper Carboniferous into the core of the WNW-ESE N-verging 'Ollo de Sapo' antiform, formed by Precambrian and Palaeozoic metasediments. Internal fabrics show that magma intrusion was contemporary with shortening. Measurements of feldspars orientations and anisotropy of magnetic susceptibility (AMS) throughout the granite are consistent and indicate a foliation striking WNW-ESE (parallel-to-folding), with a constant dip of 75-85 °N. The zonation of bulk low-field susceptibility is related to mineral content and indicates a more basic composition at the southern and western borders. The difference in elevation between outcrops (more than 600 m) allows us to infer the three-dimensional attitude of granite fabrics throughout the Massif. Syn-magmatic fabric folds are preserved in the inner part of the igneous body. The highest degree of magnetic anisotropy is observed in areas located near the bottom and top of the intrusion. At the scale of the Massif, foliation is convergent toward the bottom of the intrusion, along a line located at its northern border, where the magma source is interpreted to be located. In the western border of the Massif, the presence of C and S structures indicates that magma cooling was coeval with movement of the Chandoiro fault, a N-S striking normal fault with a N290E hanging wall displacement direction. These results indicate that emplacement of the Veiga granite is coeval with NNE-SSW shortening and with an WNW-ESE extension direction, parallel to the trend of the late folds.

Roman-Berdiel, T.; Pueyo-Morer, E. L.; Casas-Sainz, A. M.

1995-12-01

175

Shoshonitic intrusion magmatism in Pajeu-Paraiba belt: the Bom Jardim complex  

International Nuclear Information System (INIS)

The Bom Jardim complex is a multi phase intrusion emplaced within the basement of the Pajeu-Paraiba belt, in the Borborema province, N.E., Brazil, during the Pan African (Brasiliano) orogeny, 600 Ma ago. The Bom Jardim complex is primarily composed of monzonites and syenites with subordinated granites. The major and trace elements geochemistry has established a shoshonitic affinity for the monzonite-syenite assemblages, whereas the granites are clearly of a high-K calc-alkaline character. The main geochemical trends determined for the complex are the result of fractionation of mainly amphibole, biotite, alkali feldspar ±clinopyroxene within the developing magmas. The enrichment in transition metal elements, LILE and high LILE/HSFE ratios, coupled with an initial Sr sup(87)/Sr sup(86) ratio of 0.70709 is consistent with a subduction related magma source. (author)

1990-11-01

176

The origin and evolution of low-?18O magma recorded by multi-growth zircons in granite  

Science.gov (United States)

We for the first time reported low-?18O granites within craton in Bengbu uplift, southeast margin of North China Craton. Integrated ion microprobe study of ?18O and U-Pb age on single zircon grains and zircon populations, gives direct evidence for the origin and later magmatic evolution of the low-?18O granites. Three types of zircon domains are recognized: inherited magmatic core (Type I), inherited metamorphic core/mantle (Type II) and overgrown magmatic rim (Type III). Type I zircons were formed in Neoproterozoic, and have the average ?18O values of 5.3±0.6‰ around mantle value. Triassic Type II zircons have extremely low and highly heterogeneous ?18O values ranging from -9.4‰ to 8.6‰, consistent with the values and variations exhibited by metamorphic zircons from Dabie-Sulu orogen. This feature argues for a Triassic metamorphic origin for the 18O-depletion signature of zircons from ultrahigh pressure metamorphic rocks in Dabie-Sulu orogen. Jurassic Type III zircons have isotopically homogeneous ?18O values of 3.3±0.5‰. Collectively, zircon populations recorded the ?18O variations from source to low-?18O granite. The primary protolith of Jurassic granites in Bengbu uplift is a Neoproterozoic granitic intrusion in South China Block. Later high-temperature meteoric hydrothermal alteration has lowered the whole-rock ?18O values in various degrees. The low-?18O protolith was then buried to the middle-lower crust by Triassic continental subduction and Jurassic anatexis produced the low-?18O granitic magma. Moreover, ?18O values of Type III zircons are isotopically lighter than previously reported values of magmatic garnets in Jurassic granites, indicating later magmatic evolution of low-?18O magma toward high ?18O values probably as a result of infiltration of high-?18O fluid from wall-rocks.

Wang, Shui-Jiong; Li, Shu-Guang; Liu, Sheng-Ao

2013-07-01

177

Radionuclide migration through fractured granite  

International Nuclear Information System (INIS)

Radionuclide migration has been studied in natural fractures in granite blocks of up to 30 cm in length. Results are reported for four migration experiments involving synthetic groundwaters containing tritiated water, "9"5"mTc, "7"5Se, "1"3"7Cs, or "6"0Co-labelled natural colloids, which were injected into the fractures at flow rates of 0.4-0.45 mL/h, giving residence times in the fractures of up to 15 h. Also presented are the results of the post-experiment analyses, including an autoradiograph of one of the fracture surfaces, and the spatial distribution of the sorbed radionuclides determined by ?-scanning and selective chemical extractions

1988-06-13

178

AMS studies in Portuguese variscan granites  

Science.gov (United States)

A large volume of Variscan granitic rocks outcrop in Central Iberian Zone which are well documented concerning geological mapping, petrography and geochemistry but whose magnetic characteristics and fabric remain unknown. In this study we summarize the available AMS data from approximately 644 sampling stations (5152 samples) on different massifs of Variscan Portuguese granites. Despite their different geological, petrographic and geochemical characteristics, magnetic susceptibility (K) values obtained for the majority of the studied granites range from 15 to 300 × 10-6 SI. The dominant paramagnetic behaviour of the granite bodies reflects the presence of ilmenite as the main iron oxide. This feature indicates the reduced conditions involved in the granite melt formation during the Variscan orogeny. The two-mica granites show K values ranging between 15 to 70 × 10-6 SI which are lower than values displayed by the biotite-rich facies scattered within the interval of 70 and 300 × 10-6 SI. The magnetite-bearing granites are scarce but represented in Lavadores, Gerês and Manteigas. Even so, only the Lavadores body could be considered as a true magnetite-type granite (K >3.0 × 10-3 SI) in face of its K, comprised between 1550 and 19303 × 10-6 SI. Magnetic anisotropy can be used as a "marker" for the deformation experienced by granite mushes during their crustal emplacement and further cooling. Magnetic anisotropy can thus be correlated with the finite deformation of a rock, as record by mineral fabrics. Post-tectonic granites, such as those from Vila Pouca de Aguiar, Pedras Salgadas, Caria, Vila da Ponte, Chaves and Lamas de Olo, have a magnetic anisotropy Castelo Branco, Mangualde-Trancoso or Serra da Estrela, the magnetic anisotropy falls within the 2.5% and 5% range. The magnetic anisotropy of the Lavadores granite is always higher than 10%. This feature, however, reflects the presence of rough alignments of magnetite co-existent with magmatic to submagmatic microstructures. The shape parameter T is quite variable; however, the average values, for all the massifs, are always higher than zero, suggesting the presence of oblate AMS ellipsoids due to the magnetocrystalline anisotropy of biotite. The values of magnetic susceptibility and magnetic anisotropy allowed a petrophysical characterization of the paramagnetic Variscan granites as was proposed by Sant'Ovaia & Noronha (2005).

Sant'Ovaia, Helena; Martins, Helena; Noronha, Fernando

2014-05-01

179

Fission track ages of some Cenozoic acidic intrusive rocks from Ryukyu Island  

International Nuclear Information System (INIS)

The fission track ages of zircon have been measured in nine acidic intrusive rocks from the Ryukyu Islands by the arranged fix-area population method and the external-surface external-detecter grain-by-grain method. The ages are as follows: Kuchinoerabujima xenolith (granodiorite), 15.0 ± 1.2 Ma; Okinoerabujima granodiorite, 32.9 ± 2.7 Ma; Okinawajima tonalite, 30.0 ± 4.7 Ma; Okinawajima quartzporphyry, 15.7 ± 1.3 Ma, 15.3 ± 1.5 Ma, and 15.8 ± 1.7 Ma; Ishigakijima Omoto granite, 28.7 ± 0.9 Ma, 29.9 ± 0.9 Ma and 29.9 ± 1.1 Ma. These fission track ages indicate that the acidic intrusive rocks were emplaced in late Oligocene and early to middle Miocene times. (author)

1986-01-01

180

Mineralogical study of Sibolga granite as an uranium source  

International Nuclear Information System (INIS)

Mineralogical study of Sibolga granite as an uranium source. Exploration for uranium mineralization associated with granite is frequently based on the concept of genetic models of granite. S type granite commonly are uranium carrier, it is genetically ascribed to crustal anatexis of sediment because of compression in the geosyncline or in the continental arc. The granite is characterized by relatively low Na2O, with high of Al23, SiO2 and K2O. The accessory minerals are biotite, garnet, muskovite, and ilmenite. Sibolga granite partially is an alkaline granite relatively high in SiO2, Al2O3 and it contains biotite, monazite, zircon, fluorite, apatite, ilmenite, magnetite, pyrite, and small amounts of muscovite. Uranium content in the granite is relatively high, it is found in uraninite, pyrochlore, and other accessory minerals. Uranium in the granite is recognized partially as leachable uranium, which is distinctive for uranium source granite. (author). 8 figs.; 9 refs

1989-01-01

 
 
 
 
181

Adaptive Intrusion Data System (AIDS)  

International Nuclear Information System (INIS)

The adaptive intrusion data system (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique data system which uses computer controlled data systems, video cameras and recorders, analog-to-digital conversion, environmental sensors, and digital recorders to collect sensor data. The data can be viewed either manually or with a special computerized data-reduction system which adds new data to a data base stored on a magnetic disc recorder. This report provides a synoptic account of the AIDS as it presently exists. Modifications to the purchased subsystems are described, and references are made to publications which describe the Sandia-designed subsystems

1980-01-01

182

Adaptive Intrusion Data System (AIDS)  

Energy Technology Data Exchange (ETDEWEB)

The adaptive intrusion data system (AIDS) was developed to collect data from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique data system which uses computer controlled data systems, video cameras and recorders, analog-to-digital conversion, environmental sensors, and digital recorders to collect sensor data. The data can be viewed either manually or with a special computerized data-reduction system which adds new data to a data base stored on a magnetic disc recorder. This report provides a synoptic account of the AIDS as it presently exists. Modifications to the purchased subsystems are described, and references are made to publications which describe the Sandia-designed subsystems.

Corlis, N. E.

1980-05-01

183

Determination of dispersity of crushed granite  

International Nuclear Information System (INIS)

The experimental crushed granite column breakthrough curves, using 99Tc as spike tracer and 3H as invariant tracer, are analyzed by different linear regression techniques. Dispersity of crushed granite and retardation factor of 99TcO4- on the crushed granite are determined simultaneously by one linear regression technique. Dispersity of crushed granite is also obtained with 3H as invariant tracer by the other linear regression technique. The dispersities found by spike source and invariant source methods are compared. The experimental results show that the dispersity found by spike source method is close to that found by invariant source method. It indicates that dispersity is only the characteristic of dispersion medium

2004-05-01

184

Determination of dispersity of crushed granite  

International Nuclear Information System (INIS)

Experimental crushed granite column breakthrough curves, using 99Tc as spike tracer and 3H as invariant tracer, were analyzed by different linear regression techniques. Dispersity of crushed granite and the retardation factor of 99TcO4- on the crushed granite were determined simultaneously by one linear regression. Dispersity of crushed granite was also obtained with 3H as invariant tracer by the other linear regression. The dispersities found by spike source and invariant source methods are compared. Experimental results show that the dispersity found by the spike source method is close to that found by the invariant source method. This indicates that dispersity is only a characteristic of the dispersion medium. (author)

2005-06-01

185

Uranium in the Carnmenellis Granite, Cornwall, England.  

Science.gov (United States)

Samples from a 30 meter core from the Rosemanowas quarry in the Carnmenellis granite in Cornwall, England were analyzed by induced fission track detection, delayed neutron detection, backscattered electron imaging in a SEM, and energy dispersive x-ray spe...

M. W. Keith

1984-01-01

186

Intrusive rocks and tectono-metamorphic evolution of the Mako Paleoproterozoic belt (Eastern Senegal, West Africa)  

Science.gov (United States)

The Kedougou Kenieba Inlier (KKI) (Paleoproterozoic of Eastern Senegal) is a portion of the West African Craton (WAC) containing a granite-greenstone terrain that experienced three distinct periods of magmatic activity, peaking at 2200, 2160-2130 and 2100-2070 Ma. In the Inlier, Paleoproterozoic granitoids and large-scale transcurrent shear zones are spatially associated, suggesting a genetic link between magma bodies and shear zones. Granitic intrusions are associated with all the volcanic episodes and phases of deformation, and have been used to constrain the age of many of these events. Our structural data and deformation sequence indicate that the Mako Greenstone Belt and the adjacent granitoid complexes have undergone a multi-phase evolutionary history that is spread over a prolonged period. The available geochronological data and field studies allowed classification of the granitoids of the KKI into four generations GI, GII, GIII and GIV. The current data suggest that the oldest rocks in the KKI, the Badon granites (2198 ± 2 Ma) and the tonalitic gneisses from Tonkouto (2200-2198 Ma) (GI), could be correlated with an early Birimian magmatic event. The gneisses, crystallized at depth, record the earliest deformation and in contrast to other tonalites, do not appear to have intruded volcanic rocks. The second manifestation of magmatism was intrusion of mafic diorite - the Gabbro Sandikounda Layered Igneous Complex type (GII) and development of the Laminia Kaourou Plutonic Complex (LKPC) (2160-2130 Ma). These bodies pre-date or are sometimes synchronous with a major deformational episode, and may, therefore, have formed very early in convergent Birimian orogenesis. The third major peak of magmatic activity occurred after the above major episode with the development of the oval shaped Diombalou and Bouroumbourou plutons (GIII). The orientation of these plutons parallel to the regional strike of the schistosity indicates structural control on granite emplacement. Eburnean magmatism was terminated in the Mako Belt following compressional Eburnean deformation, with the emplacement of the Tinkoto, Mamakono plutons (GIV) in the east of the complex and continued in the Dialé-Daléma supergroup with the syntectonic emplacement of the Saraya batholith. Garnitiferous granites of crustal derivation were emplaced in the final period of extensional activity around 2080 Ma. Field observations suggest the early plutons of the complex granitic (Kakadian) batholith intruded during convergent deformation whereas later igneous activity accompanied regional orogen-parallel extension, followed by exhumation. In the Mako Belt, thickening of the crust was proposed to have caused heating and the 'apparent diapiric rise' of the Diombalou and Bouroumbourou plutons.

Gueye, Mamadou; Ngom, Papa Malick; Diène, Mouhamadane; Thiam, Yaouba; Siegesmund, Siegfried; Wemmer, Klaus; Pawlig, Sabine

2008-02-01

187

The Maua granitic massif, Central Ribeira Belt, Sao Paulo, Brazil: petrography, geochemistry and U-Pb dating  

Energy Technology Data Exchange (ETDEWEB)

The Maua granitic massif is an elongated body dominated by a porphyritic biotite monzogranite which grades, in its southwestern extremity, to lighter equi granular granite and greisenized (tourmaline)-biotite-muscovite leuco granite. Abundant enclaves can be divided in three types: grey micro granular enclaves, with rounded shapes and igneous textures, are compositionally similar to the enclosing porphyritic granites; dark, rounded, micaceous enclaves have high K/Na, and may correspond to highly assimilated meta sedimentary xenoliths; and angulous gneiss xenoliths seem to be fragments of an unexposed type of country rock. The primitive magmas that formed the massif were Zr, P and LREE-saturated, and became progressively enriched in U, Cs, Y, HREE, F and possibly Ta. Geochemical data show that most of the observed compositional variation can be a reflection of crystal fractionation at the level of emplacement. However, other processes such as magma mixing, contamination and post-magmatic alteration seem to respond for local chemical variations. U-Pb monazite dating point to a crystallization age of 588 {+-} 2 Ma which is ca. 20 myr. younger than those of nearby crust-derived syn-orogenic granites. (author)

Filipov, Marcelo [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia de Minas]. E-mail: filipov@usp.br; Janasi, Valdecir de Assis [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias]. E-mail: vajanasi@usp.br

2001-09-01

188

Geochemical and Sr-isotopic signatures in the 2.6 B.Y. Lepakshi granite, Anantapur district, Andhra Pradesh: implications for its origin and evolution  

International Nuclear Information System (INIS)

The predominantly leucocratic 2.6 b.y. old Lepakshi granite (a suite of granite, granodiorite and quartz-monzonite), near Hindupur in the Anantapur district of Andhra Pradesh is intrusive into the Archaean schistose rocks and contains xenolithic patches of amphibolite. Compositionally, it is predominantly quartz-monzonitic with granodiorite and granite variants. The relatively low initial 87Sr/86Sr (Sri = 0.7026) of this Lepakshi granite implies its derivation from a juvenile crustal source with very limited crustal residence time, indicating the absence of involvement of any metasedimentary source. The source also appears to have fair amount of mafic component. A volcanic arc type tectonic setting, along with the collision processes and the associated tectonic activity operating in tandem, resulting in an increased P-T regime, granulite facies metamorphism and anatectic melting at mid- to lower crustal levels is suggested for the origin of this granite. The large ion lithophile (LIL) elements removed from the lower crust (due to granulite facies metamorphism and the associated fluid activity) were incorporated in the granites of the Lepakshi type. (author). 45 refs., 12 figs., 2 tabs

1992-01-01

189

Magmatic Evolution of the REE-rich, Strange Lake A-type Peralkaline Granite  

Science.gov (United States)

Although A-type granitic peralkaline complexes are widely distributed in anorogenic tectonic settings and many of them contain elevated concentrations of the REE and other HFSE, their evolution, and particularly the processes controlling the concentration of the REE/HFSE, is still poorly understood. The 1240 Ma (Miller et al., 1997) Strange Lake peralkaline granitic pluton, northern Québec-Labrador, Canada is an extraordinary example of hyper-enrichment of the REE, Zr, and Nb in an A-type granite, and an ideal setting in which to study late stage granitic melt evolution. At least four intrusive phases are distinguishable in the six km diameter cylindrical pluton, based on grain-size, mineralogical composition, and crystallization sequence deduced from petrographic examination. The first and least evolved phase, a hypersolvus granite, is characterized by a high proportion of early crystallizing perthite and subordinate proportions of late crystallizing arfvedsonite and quartz. The subsequent subsolvus granite is distinguished from the hypersolvus granite by early crystallizing arfvedsonite and quartz, and the occurrence of discrete albite and microcline crystals rather than perthite. A third, porphyritic granite type occurs as a quenched zone between the hypersolvus and subsolvus granites, and it shows features of both granite types. Pegmatites, emplaced as sheets at the top of the pluton were the last igneous phase to form and are of special interest because they host the bulk of the mineralization. A model is proposed in which the first step was evolution of the hypersolvus granite by crystallization of alkali feldspar, as proposed previously by Boily and Williams-Jones (1994). This evolution is manifested by trends of decreasing whole-rock concentrations of K2O with Al2O3 and corresponding increases in REE, HFSE and F. The second step was marked by a change in the magma evolution due to the appearance of arfvedsonite as a liquidus mineral in place of perthite. This led to a decrease in Fe accompanied by a continued increase in HFSE, REE and F; the co-crystallization of quartz had the effect of increasing the concentrations of all elements except Si. Significantly, the arfvedsonite contains appreciable concentrations of REE (up to 1 wt. %) and F (up to 3.4 wt. %). Indeed local cumulates of arfvedsonite may contain whole-rock concentrations of up to 1.4 wt. % TREO and 0.5 wt. % ZrO2. However, the concentrations of HFSE and REE increased in the melt despite the fractional crystallization of arfvedsonite. This was due to the greater proportions of minerals free of REE and HFSE that were crystallizing (feldspar and quartz). The hyper-enrichment in REE and HFSE in the pegmatites is interpreted to have been due to the incompatible nature of these elements, the small proportion of the residual liquid forming the pegmatites, the extreme alkalinity of this liquid and the complexation of the REE and HFSE with fluorine. Miller, R.R., Heaman, L.M., and Birkett, T.C. (1997) Precambrian Research, 81, 67-72 Boily, M. and Williams-Jones, A.E. (1994) Contributions to Mineralogy and Petrology, 118(1), 33-47

Siegel, K.; Williams-Jones, A. E.

2013-12-01

190

The Lagoa Real subalkaline granitic complex (south Bahia, Brazil): a source for uranium mineralizations associated with Na-Ca metasomatism  

International Nuclear Information System (INIS)

In the central zone of the Sao Francisco Craton (South Bahia), the lower Proterozoic Lagoa Real granites and orthogneisses overthrust to the West the younger Urandi and Espinhaco metamorphic series, probably a late Brazilian event. This thrust is related to the regional metamorphism (amphibolite facies) of the Lagoa Real granites and induces a reverse HP metamorphism in the over thrusted series. Undeformed granites (sao Timoeto type) present two feldspars, perthitic orthoclase largely predominant over plagioclase (oligoclase ? albite), blue quartz, Fe-rich amphibole and biotite ± clinopyroxene assemblages, ilmenite ? magnetite, zircon, apatite, allanite and Nb ± Ti-REE oxides and silicates. The crystallization of the granites begins at high temperature and under low fO2 and PH2O conditions. Fractional crystallization of pyroxene and plagioclase leads to silica enrichment during magmatic differentiation. Increasing fO2 and PH2O are observed during this evolution. Orthogneisses show strongly recrystallized paragenesis: equal abundance of non-perthitic microcline and plagioclase (oligoclase ? albite), quartz, more Al-rich amphibole and biotite, magnetite, sphene, zircon, allanite, Nb ± Ti-REE oxides and silicates, and ± apatite. HT Na and Ca metasomatism occurs 330 Ma later than granite emplacement and is synchronous with important uranium mineralizations. Major elements and trace-elements geochemistry of the granites and orthogneisses indicate subalkaline to alkaline typology. Incompatible behaviour of Th, REE, Y, Zr, Nb, and F points out a convergence with alkaline magmatism. CI, F, Th, Y, REE, NB enrichments and Ba, Sr depletions are also related to a late magmatic stage. U-Th-rich and metamict accessory minerals of the granites represent a favorabl source for the Lagoa Real uranium ore-deposits

1987-01-01

191

Rn-222 release to the environment: comparison between different granite sources  

International Nuclear Information System (INIS)

In this work three different types of granites were studied, namely: pure granite, alkali granite and altered (hydrated) alkali granite. General radioactivity of the granites was studied along with the potential for 222Rn emanation. The study indicated that altered alkali granite releases, relatively, the highest 222Rn emanation to the surrounding air while alkali granite emits the more intense gamma radiation of the three granites. Hence, altered alkali granite can be used as a laboratory source for 222Rn.

2004-02-24

192

Lead-isotopic and geochemical evidence for distinct granite sources and basement terranes in New England  

Energy Technology Data Exchange (ETDEWEB)

Three fundamentally distinct sources of Devonian granitic rocks in Maine are shown by lead isotopic data on plutons of the Avalonian (A), Central Maine (CM), and North American craton (NAC) regions. Feldspar and whole rock from plutons and country rocks along a broad traverse across the Appalachians from Penobscot Bay to the Chain Lakes Massif, Maine, were analyzed for Pb, U, and Th. A broad gradient is formed by the three isotopic groups: upper continental crustal values for granites in A, orogenic values for CM, and relatively unradiogenic values for NAC. Granites from all groups have higher radiogenic lead values than those found in oceanic basalt. Plutons in A, south of the Norumbega fault zone, show the most heterogeneous lead values suggesting that A may consist of additional isotopically distinguishable domains. This suggestion is consistent with the wide range in initial Sr and O in the petrographically and bulk-chemically diverse intrusives in A. The diversity in lead isotopic compositions is consistent with the lack of gradients in bulk composition, and of initial Sr and O. The chemical differences probably reflect sources in each of the three regions that had different ages and evolutionary histories which were juxtaposed before magma formation and pluton emplacement.

Ayuso, R.A.

1985-01-01

193

Mineralogy, chemistry, and age of granitic veins at Nicholson's Point, South Coast, Natal  

International Nuclear Information System (INIS)

Undeformed granitic veins exposed at Nicholson's Point, southern Natal, intrude nearly all the foliated rock types between Drakes Beach and Leisure Bay and therefore appear to post-date the major deformation episodes. The veins define an en echelon array and appear to have been emplaced syn-tectonically to post-tectonically. In addition to quartz and feldspar, the veins are characterized by variable ferro magnesian minerals, namely, tourmaline, magnetite, dumortierite, and biotite. A Rb/Sr isotope study yields a date of 960 ± 32 Ma which is within error of the date of the nearby deformed Glenmore Granite. These results imply that much of the deformation history recorded in the southern sector of Natal Structural and Metamorphic Province either occurred within a relatively short period or that the age of the Glenmore Granite is a reset age. The veins represent one of the youngest events recognized in the tectonic and intrusive history of the Natal Structural and Metamorphic Province. 18 refs., 7 figs., 5 tabs

1992-08-01

194

Mixed Caledonian appinite magmas: implications for lamprophyre fractionation and high Ba-Sr granite genesis  

Science.gov (United States)

Ach'Uaine Hybrid appinites represent a rare example of lamprophyric magmas that were demonstrably exactly contemporaneous with felsic differentiates, preserved within a suite of minor, hypabyssal intrusions emplaced at the end of the Caledonian orogeny in northern Scotland. Numerous small stocks, bosses and dykes show outcrop-scale relationships characteristic of mingling between lamprophyric and syenitic magmas, and are commonly cut by sharp-sided granite veins. The mafic rocks are characterised by Ni and Cr abundances and MgO sufficiently high to signal derivation from a mantle source within which radiogenic 87Sr/86Sr and nonradiogenic 143Nd/144Nd ratios require significant time-integrated incompatible element enrichment. This is manifest in high Ba, Sr and light REE abundances and incompatible element ratios in the derived magmas directly comparable with those of high Ba-Sr granitoids and related rocks. Quantitative major element, trace element, radiogenic and stable isotope modelling is consistent with early fractionation of clinopyroxene and biotite, accompanied by minor crustal assimilation, having driven the evolving lamprophyric magma to cogenetic syenite. Subsequent derivation of granite required a major change to feldspar-dominated crystal fractionation with continued, still minor contamination. The elemental and isotopic characteristics of the granitic terminus are so similar to high Ba-Sr granitoids both locally and worldwide, that these too may have had large mantle components and represent significant juvenile additions to the crust.

Fowler, M. B.; Henney, P. J.

1996-12-01

195

Head and neck malignancies in younger patients  

International Nuclear Information System (INIS)

We treated 23 (1.4% of all our primary cases) younger patients who are from 15 years old to 29 years old with head and neck malignancies at the Department of Head and Neck Surgery of the Miyagi Cancer Center Hospital for the past 12 years. There were 12 male and 11 female, and the sex ratio was approximately 1:1. There were 12 oral cancer patients, 6 epipharyngeal cancer patients and so on. There were 14 squamous cell carcinomas, 3 nasopharyngeal carcinomas and so on. 60% of all cases were squamous cell carcinomas. Clinically, advanced stage (stage III and IV) was diagnosed in 70% of patients at presentation. Although 19 patients had no past history, 2 patients had bronchial asthma, one had schizophrenia, and one had psychological disorder. Radical treatment was performed in 20 of 23 examples. The estimated Kaplan-Meier 5-year cause-specific survival rates for all patients were 76% and the 10-year cause-specific survival rates were 63%, respectively. It was thought that survival consequence was excellent in the whole. The problems of head and neck tumor treatment in a younger patient were thought about with late effect by radioactive rays and genital disorder by cancer chemotherapy. (author)

2006-09-01

196

Meltwater routing and the Younger Dryas  

Science.gov (United States)

The Younger Dryas—the last major cold episode on Earth—is generally considered to have been triggered by a meltwater flood into the North Atlantic. The prevailing hypothesis, proposed by Broecker et al. [1989 Nature 341:318–321] more than two decades ago, suggests that an abrupt rerouting of Lake Agassiz overflow through the Great Lakes and St. Lawrence Valley inhibited deep water formation in the subpolar North Atlantic and weakened the strength of the Atlantic Meridional Overturning Circulation (AMOC). More recently, Tarasov and Peltier [2005 Nature 435:662–665] showed that meltwater could have discharged into the Arctic Ocean via the Mackenzie Valley ?4,000 km northwest of the St. Lawrence outlet. Here we use a sophisticated, high-resolution, ocean sea-ice model to study the delivery of meltwater from the two drainage outlets to the deep water formation regions in the North Atlantic. Unlike the hypothesis of Broecker et al., freshwater from the St. Lawrence Valley advects into the subtropical gyre ?3,000 km south of the North Atlantic deep water formation regions and weakens the AMOC by 30%. We conclude that meltwater discharge from the Arctic, rather than the St. Lawrence Valley, was more likely to have triggered the Younger Dryas cooling.

Condron, Alan; Winsor, Peter

2012-01-01

197

Meltwater routing and the Younger Dryas.  

Science.gov (United States)

The Younger Dryas--the last major cold episode on Earth--is generally considered to have been triggered by a meltwater flood into the North Atlantic. The prevailing hypothesis, proposed by Broecker et al. [1989 Nature 341:318-321] more than two decades ago, suggests that an abrupt rerouting of Lake Agassiz overflow through the Great Lakes and St. Lawrence Valley inhibited deep water formation in the subpolar North Atlantic and weakened the strength of the Atlantic Meridional Overturning Circulation (AMOC). More recently, Tarasov and Peltier [2005 Nature 435:662-665] showed that meltwater could have discharged into the Arctic Ocean via the Mackenzie Valley ~4,000 km northwest of the St. Lawrence outlet. Here we use a sophisticated, high-resolution, ocean sea-ice model to study the delivery of meltwater from the two drainage outlets to the deep water formation regions in the North Atlantic. Unlike the hypothesis of Broecker et al., freshwater from the St. Lawrence Valley advects into the subtropical gyre ~3,000 km south of the North Atlantic deep water formation regions and weakens the AMOC by 30%. We conclude that meltwater discharge from the Arctic, rather than the St. Lawrence Valley, was more likely to have triggered the Younger Dryas cooling. PMID:23129657

Condron, Alan; Winsor, Peter

2012-12-01

198

CDC Vital Signs: Preventing Pregnancies in Younger Teens  

Science.gov (United States)

... Vital Signs Share Compartir Preventing Pregnancies in Younger Teens April 2014 1 in 4 More than 1 ... including HIV/AIDS. Issue Details Problem Many younger teens give birth at ages 15 to 17. More ...

199

Intrusion Detection Using Data Mining Technique  

Directory of Open Access Journals (Sweden)

Full Text Available In reality it is not possible to prevent security breaches completely using the existing security technologies. The intrusion detection plays an important role in network security and information system. However, many current intrusion detection systems (IDSs are signature based systems. The signature based IDS also known as misuse detection looks for a specific signature to match, and identify an intrusion. When the signatures or patterns are provided, they can detect all known attack patterns, but there are some problems for unknown attacks. The rate of false positives is very low but these types of systems are poor at detecting new attacks, variation of known attacks or attacks that act as normal behavior. Statistical Based Intrusion detection System (SBIDS can overcome many of the aforementioned limitations of signature based intrusion detection systems. Statistical based intrusion detection systems performs better than signature based intrusion detection system for novelty detection i.e. detection of new attack is very important for intrusion detection system. Researchers have implemented various classification algorithms for intrusion detection. This dissertation evaluates a decision tree classifier over a benchmark dataset. It will help intrusion detection system in novelty detection i.e. detection of new attacks. KDD99 dataset is used as the training data set

Stuti Singh

2013-03-01

200

Towards an Effective Intrusion Response Engine Combined with Intrusion Detection in Ad Hoc Networks  

CERN Multimedia

In this paper, we present an effective intrusion response engine combined with intrusion detection in ad hoc networks. The intrusion response engine is composed of a secure communication module, a local and a global response module. Its function is based on an innovative tree-based key agreement protocol while the intrusion detection engine is based on a class of neural networks called eSOM. The proposed intrusion response model and the tree-based protocol, it is based on, are analyzed concerning key secrecy while the intrusion detection engine is evaluated for MANET under different traffic conditions and mobility patterns. The results show a high detection rate for packet dropping attacks.

Mitrokotsa, Aikaterini; Douligeris, Christos

2008-01-01

 
 
 
 
201

Wireless Intrusion Detection and Logging System  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion detection is the security patrol, and become the eyes and ears of the network, alerting the potential vulnerabilities and intrusion attempts. Monitoring can help to spot problems in the network, as well as identify performance problems, but watching every second of traffic that passes through the network, manually searching for attacks, would be impossible. This is why there is need of specialized network intrusion detection software. This software inspects all network traffic, looking for potential attacks and intrusions. Wireless Intrusion Detection System (WIDS is wireless network sniffing tool. It is used for securing the WLAN. And it generates the alarms to the administrator as soon as something goes wrong in the WLAN.WIDS attempts to identify computers system, network intrusions and misuse by gathering and analyzing data.WIDS can monitor and analyze user and system activities. It generates the alerts based either on predefined signatures or on anomalies in the traffic.

SURAJ KENDHEY

2013-03-01

202

Corrective nasal surgery in the younger patient.  

Science.gov (United States)

IMPORTANCE To describe clinical parameters for the management of the pediatric patient with nasal anatomical deformity or functional impairment. OBJECTIVES To review the authors' experience with corrective nasal surgery in pediatric patients and make recommendations regarding indications for surgery and surgical techniques. DESIGN, SETTING, AND PARTICIPANTS A retrospective medical chart review was performed for all male patients younger than 16 years and female patients younger than 14 years seen by the senior author (F.G.F.) at a tertiary referral center between August 1996 and August 2012. The database was searched for patients who underwent septoplasty or corrective nasal surgery by the senior author. EXPOSURES Patients included in the study underwent either septoplasty or corrective nasal surgery by the senior author. MAIN OUTCOMES AND MEASURES Age, indication for surgery, surgery performed, and last follow-up appointment was recorded for each patient. In addition, any complications or need for revision surgical or adjunct procedures were noted. RESULTS Demographics and outcomes for 54 pediatric patients were included in the study. The most common indications for surgery were posttraumatic deformities (n = 36) and severe airway obstruction (n = 48). Fifteen patients with severe nasal airway obstruction did not have a documented history of trauma. The mean follow-up period was 646 days (approximately 21 months), with a range of 8 to 4062 days. Five patients underwent a staged procedure, and no patients underwent a revision procedure for unsatisfactory results. CONCLUSIONS AND RELEVANCE Children with nasal obstruction and deformity can safely undergo nasal corrective surgery prior to adolescence. Special considerations include preserving normal structures and the judicious use of grafts. The recommended approaches to managing the pediatric septoplasty and nasal surgery patient are described herein through a series of representative cases. PMID:24503713

Adil, Eelam; Goyal, Neerav; Fedok, Fred G

2014-01-01

203

Intrusion scenarios in fusion waste disposal sites  

International Nuclear Information System (INIS)

Results of analyses on human intrusions into repositories of fusion radioactive waste are presented. The main topics are: duration of the institutional control, occurrence of intrusion, intrusion scenarios, acceptable risk limits and probabilistic data. Application to fusion waste repositories is implemented with a computational model: wells drilling is considered as the possible scenario. Doses and risks to intruder for different SEAFP-2 cases turn out to be very small. No intervention to reduce the hazard is necessary. (authors)

1998-09-07

204

Sorption behaviour of granite for radionuclides in groundwater condition  

International Nuclear Information System (INIS)

The sorption behavior of granite for Cs and Nd in the underground water condition was investigated as the function of mineralogical alteration of granite and particle size. The physicochemical characterization of the granite samples was carried out in terms of mineral phase, pore structure and elements eluted by soft acid treatment as the function of alteration of the granite. The increase of porosity of granite, and phase change of biotite and plagioclase into chlorite and illite, respectively were observed with the increase of alteration degree. The sorption capacities of the series of granites slightly increased with the increase of alteration degree. (authors)

2009-01-01

205

Regional and contact metamorphism within the Moy Intrusive Complex, Grampian Highlands, Scotland  

Science.gov (United States)

In central Scotland, the Moy Intrusive Complex consists of (1) the Main Phase — syntectonic peraluminous granodiorite to granite emplaced at c. 455 Ma, intruded by (2) the Finglack Alaskite — post-tectonic leucocratic granite emplaced at 407+/-5 Ma. The Main Phase was emplaced into country rocks at amphibolite facies temperatures. Rb-Sr dates and a compositional spectrum of decreasing celadonite content in Main Phase muscovite suggest the persistence of c. 550° C temperatures for c. 30 Ma but with a declining pressure regime, i.e. isothermal uplift. The Finglack Alaskite was intruded at high structural level, leading to the development of a contact metamorphic aureole in the Main Phase. The thermal effects of contact metamorphism include intergrowths of andalusite, biotite and feldspar in pseudomorphs after muscovite. This is associated with recrystallized granoblastic quartz. Muscovite breakdown and reaction with adjacent biotite, quartz and feldspar, i.e. a function of local mineral assemblage rather than bulk rock composition, is postulated to explain the occurrence of metamorphic andalusite in a granitoid rock. The Main Phase pluton of the Moy Intrusive Complex lies within a NNE trending belt of c. 450 Ma Caledonian tectonic and magmatic activity paralleling the Moine Thrust, and extending from northern Scotland to the Highland Boundary Fault. Syntectonic ‘S-type’ magmatism with upper crustal source areas implies crustal thickening and suggests an intracratonic orogeny.

Zaleski, E.

1985-04-01

206

Intrusion Preventing System using Intrusion Detection System Decision Tree Data Mining  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: To distinguish the activities of the network traffic that the intrusion and normal is very difficult and to need much time consuming. An analyst must review all the data that large and wide to find the sequence of intrusion on the network connection. Therefore, it needs a way that can detect network intrusion to reflect the current network traffics. Approach: In this study, a novel method to find intrusion characteristic for IDS using decision tree machine lea...

Syurahbil; Noraziah Ahmad; Zolkipli, M. F.; Abdalla, Ahmed N.

2009-01-01

207

Regional S-type granites in the Ecuadorian Andes: Possible remnants of the breakup of western Gondwana  

Science.gov (United States)

Reconnaissance geological mapping of the Ecuadorian Cordillera Real has established the presence of a previously unrecognized regional suite of variably deformed granitoids for which poorly constrained Rb?Sr whole-rock data indicate a minimum Early Jurassic age of 200 ± 12 Ma (initial ratio = 0.7120). This suite, which is associated with low- to medium-grade, semipelitic metamorphic rocks, is dominated by peraluminous monzogranites containing biotite ± garnet ± muscovite. Geochemically, these granites are S-types and can be readily distinguished from juxtaposed I-type granitoids of the Middle-Upper Jurassic Zamora, Abitagua, and Azafrán batholiths located immediately to the east. Intrusion of these S-type granites may be related to the breakup of western Gondwana.

Aspden, J. A.; Fortey, N.; Litherland, M.; Viteri, F.; Harrison, S. M.

1992-10-01

208

Radiometric analysis of Chinese commercial granites  

International Nuclear Information System (INIS)

Due to the widespread use of granites as building and ornamental materials, measurements of 226Ra, 232Th and 40K activities in commercial granites have been carried out using a NaI(Tl) ?-ray spectrometer with a matrix-inversion-based spectral stripping technique. The concentrations of 226Ra, 232Th and 40K in Chinese commercial granite range from 14.5 to 204.7 Bq x kg-1, 16.7 to 186.7 Bq x kg-1 and 185.7 to 1745.6 Bq x kg-1, respectively. The mean values of the activity concentrations of 226Ra, 232Th and 40K in red and pink commercial granites are all higher than those in black and gray commercial ones. The radium equivalent activity (Raeq), the external hazard index (Hex), the internal hazard index (Hin ) and the annual gonadal dose equivalent (AGDE) were also calculated and compared to the international recommended values. Six types of red commercial granites (CBR, MLR, QXR, PBR, JXR, LQR, YDR and TSR) of China do not satisfy the universal standards. (author)

2006-03-01

209

Mantle-crustal Source of Mafic-felsic Magmas in the Dubr-Igla Intrusive Complex, Egypt: Inference from Geochemistry and Sr-Nd Isotopic Study ????? ??????????? ???????? ?????????? - ????????? ?????????? - ???????? ????? ???? - ???? ???????? ???? : ???? ??????? ?????? - ????? ???????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Dubr-Igla intrusive complex (DIC) is a composite batholith intruded into the Pan-African terrain of the Egyptian basement complex. It represents an uplifted tectonic block, comprising a diverse rock association ranging from gabbro to granite. These rocks belong to two distinct suites; the gabbroid-diorite (maficintermediate) and granodiorite-monzogranite (felsic) suites. The gabbroid- diorite suite has a calc-alkaline affinity and an overall depletion of Nb, Y, K, and Rb with slightly fra...

MOHAMED HASSANEN

1999-01-01

210

The GRANIT project: Status and Perspectives  

CERN Document Server

The GRANIT project is the follow-up of the pioneering experiments that first observed the quantum states of neutrons trapped in the earth's gravitational field at the Institute Laue Langevin (ILL). Due to the weakness of the gravitational force, these quantum states exhibit most unusual properties: peV energies and spatial extensions of order 10 $\\mu$m. Whereas the first series of observations aimed at measuring the properties of the wave functions, the GRANIT experiment will induce resonant transitions between states thus accessing to spectroscopic measurements. After a brief reminder of achieved results, the principle and the status of the experiment, presently under commissioning at the ILL, will be given. In the second part, we will discuss the potential of GRANIT to search for new physics, in particular to a modified Newton law in the micrometer range.

ler, Stephan Baeß; Grigorieva, Ludmilla; Kreuz, Michael; Naraghi, Fabrice; Nesvizhevsky, Valery; Pignol, Guillaume; Protassov, Konstantin; Rebreyend, Dominique; Vezzu, Francis; Voronin, Alexei

2012-01-01

211

Fluid inclusion planes and paleofluid records in the Podlesí granite, Krušné hory Mts., Czech Republic  

Directory of Open Access Journals (Sweden)

Full Text Available Three generations of fluid inclusion planes (FIP were distinguished in rocks of the PTP-3 borehole from the Podlesí granite stock (Krušné hory Mts.. The oldest generation of FIP is believed to have followed the propagation of proto-tectonic subhorizontal aplite dykes and steep veinlets of greisen mineralization, at temperatures of about 400 °C and pressures less than 100 MPa. The later FIP contain fluid inclusions with homogenization temperatures from 140 to 270 °C, and likely represent hydrothermal fluids associated with the repeated opening of fractures during the late stages of intrusive complex development.

Dobeš P

2005-06-01

212

What controls chemical variation in granitic magmas?  

Science.gov (United States)

Consideration of the models that have been applied to explain the chemical variations within granitic rock suites shows that most are inadequate to account for the main variations. This stems from a variety of model deficiencies, ranging from physical or energetic inadequacies to incompatibility with the chemical data or internal inconsistency between models based on, for example, isotope or trace-element data and major-element data. We contend that any model that fails any of these tests of internal consistency cannot be considered further. Thus, although we can point to examples in which many of the traditionally accepted mechanisms have played secondary roles in producing variation, there presently remains but one viable choice for the primary mechanism by which most granitic magmas acquire compositions beyond the range defined by the compositions of crustal melts. That primary mechanism is peritectic assemblage entrainment (PAE). We infer that once a partial melt has formed in a crustal protolith it may segregate from its complementary solid residue carrying small crystals of the peritectic phase assemblage formed in the melting reaction, and that the ratios of individual peritectic minerals in the entrained assemblage remains fixed in the ratio decreed by the stoichiometry of the melting reaction. For those elements with low solubilities in granitic melts, PAE (in varying degrees), accompanied by co-entrainment of accessory minerals, is responsible for most of the primary elemental variation in granitic magmas. In contrast, the concentrations of elements with high solubilities in silicic melts reflect the protolith compositions in a simple and direct way. The source is the primary control on granite magma chemistry; it dictates what is available to dissolve in the melt and what will be formed as the entrainable peritectic assemblage. The apparent complexity in granitic rock suites is largely a consequence of these processes in the source. All other mechanisms contribute only as a secondary overlay.

Clemens, J. D.; Stevens, G.

2012-03-01

213

Sorption behavior of americium on granite  

International Nuclear Information System (INIS)

In this paper, the sorption behavior of Am on granite and its rock-forming minerals in Beishan groundwater under the aerobic and anoxic conditions was studied by batch experiment. The equilibrium time was determined firstly and effects of some factors such as concentration of Am, pH value of aqueous and the presence of humic acid were investigated, and sorption mechanism was discussed simply. The results of the experiment show that granite has great adsorptive capacity of Am, and pyrite plays an important part in the sorption behavior. (authors)

2009-08-01

214

10 CFR 63.322 - Human intrusion scenario.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Human intrusion scenario. 63.322 Section 63.322...Health and Environmental Standards Human Intrusion Standard § 63.322 Human intrusion scenario. For the purposes of the...

2010-01-01

215

Iron content and reducing capacity of granites and bentonite  

International Nuclear Information System (INIS)

The iron contents in various granites and in bentonite have been determined. For granites, the content is usually in the range 1-9% (weight) and 2.5-3% for bentonite. Most of the iron is divalent in the granites (70-90%); in bentonite the divalent fraction is 25-50%. A large part of the divalent iron in the granites appears to be accessible for the reduction of dissolved oxygen in an aqueous system. (author)

1983-01-01

216

Self-adaptive web intrusion detection system  

CERN Document Server

The evolution of the web server contents and the emergence of new kinds of intrusions make necessary the adaptation of the intrusion detection systems (IDS). Nowadays, the adaptation of the IDS requires manual -- tedious and unreactive -- actions from system administrators. In this paper, we present a self-adaptive intrusion detection system which relies on a set of local model-based diagnosers. The redundancy of diagnoses is exploited, online, by a meta-diagnoser to check the consistency of computed partial diagnoses, and to trigger the adaptation of defective diagnoser models (or signatures) in case of inconsistency. This system is applied to the intrusion detection from a stream of HTTP requests. Our results show that our system 1) detects intrusion occurrences sensitively and precisely, 2) accurately self-adapts diagnoser model, thus improving its detection accuracy.

Guyet, Thomas; Wang, Wei; Cordier, Marie-Odile

2009-01-01

217

Intrusion-Aware Alert Validation Algorithm for Cooperative Distributed Intrusion Detection Schemes of Wireless Sensor Networks  

Directory of Open Access Journals (Sweden)

Full Text Available Existing anomaly and intrusion detection schemes of wireless sensor networks have mainly focused on the detection of intrusions. Once the intrusion is detected, an alerts or claims will be generated. However, any unidentified malicious nodes in the network could send faulty anomaly and intrusion claims about the legitimate nodes to the other nodes. Verifying the validity of such claims is a critical and challenging issue that is not considered in the existing cooperative-based distributed anomaly and intrusion detection schemes of wireless sensor networks. In this paper, we propose a validation algorithm that addresses this problem. This algorithm utilizes the concept of intrusion-aware reliability that helps to provide adequate reliability at a modest communication cost. In this paper, we also provide a security resiliency analysis of the proposed intrusion-aware alert validation algorithm.

Young-Jae Song

2009-07-01

218

Intrusion Preventing System using Intrusion Detection System Decision Tree Data Mining  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: To distinguish the activities of the network traffic that the intrusion and normal is very difficult and to need much time consuming. An analyst must review all the data that large and wide to find the sequence of intrusion on the network connection. Therefore, it needs a way that can detect network intrusion to reflect the current network traffics. Approach: In this study, a novel method to find intrusion characteristic for IDS using decision tree machine learning of data mining technique was proposed. Method used to generate of rules is classification by ID3 algorithm of decision tree. Results: These rules can determine of intrusion characteristics then to implement in the firewall policy rules as prevention. Conclusion: Combination of IDS and firewall so-called the IPS, so that besides detecting the existence of intrusion also can execute by doing deny of intrusion as prevention.

Syurahbil

2009-01-01

219

Intrusion-aware Alert Validation Algorithm for Cooperative Distributed Intrusion Detection Schemes of Wireless Sensor Networks  

CERN Document Server

Existing anomaly and intrusion detection schemes of wireless sensor networks have mainly focused on the detection of intrusions. Once the intrusion is detected, an alerts or claims will be generated. However, any unidentified malicious nodes in the network could send faulty anomaly and intrusion claims about the legitimate nodes to the other nodes. Verifying the validity of such claims is a critical and challenging issue that is not considered in the existing cooperative-based distributed anomaly and intrusion detection schemes of wireless sensor networks. In this paper, we propose a validation algorithm that addresses this problem. This algorithm utilizes the concept of intrusion-aware reliability that helps to provide adequate reliability at a modest communication cost. In this paper, we also provide a security resiliency analysis of the proposed intrusion-aware alert validation algorithm.

Shaikh, Riaz Ahmed; Auriol, Brian J d; Lee, Heejo; Lee, Sungyoung; Song, Young-Jae; 10.3390/s90805989

2009-01-01

220

Igneous origin of K-feldspar Megacrysts in Granitic Rocks of the Sierra Nevada Batholith  

Science.gov (United States)

Study of the four principal K-feldspar megacrystic granitic plutons and related porphyrys in the Sierra Nevada composite batholith indicates that the included megacrysts are phenocrysts that grew in contact with granitic melt in long-lasting magma chambers. These 89-83 Ma plutons or intrusions are the youngest in the range, and represent the culminating magmatic phase of the batholith. They are the: Granodiorite of Topaz Lake; Cathedral Peak Granodiorite, Mono Creek Granite, Whitney Granodiorite, Johnson Granite Porphyry, and Golden Bear Dike. The zoned megacrysts in each of these igneous bodies attain 4-10 cm in length and all display oscillatory zoning with each zone beginning with a sharp increase followed by a gradual decrease in the concentration of BaO - commonly from 3 to 1 weight percent. Some of the more pronounced zones overlie resorption and channeling features on the underlying zone. Trains of small mineral inclusions (plagioclase, biotite, hornblende, quartz, sphene, and accessory minerals) are parallel to the BaO-delineated zones. The long axes of the inclusions are preferentially aligned parallel to the zone boundaries and inclusions are sorted by size from zone to zone. The growth temperature of sphene included in K-feldspar megacrysts is estimated by use of a Zr-in-sphene geothermometer. The sphene grains all yield igneous temperatures, mainly 735 - 760 °C. Sphene grains in the granodiorite host marginal to the megacrysts range to lower growth temperatures, in some instances into the subsolidus range. The zoning of the megacrysts, their presence in quenched porphry dikes, and the limited range and igneous values of growth temperatures of sphene inclusions within them, support the interpretation that the megacrysts formed as igneous sanidine phenocrysts, and that intrusion temperatures varied by only small amounts while the megacrysts grew. Each Ba- enriched zone was apparently formed by a repeated surge of new, hot melt injected into the large magma chamber represented by the plutons. Each recharge of hot magma offset cooling, maintained the partially molten or mushy character of the chamber, and induced convective currents that would loft settling megacrysts back up into the chamber. These processes continued long enough to provide the necessary conditions for the growth of these extraordinarily large K-feldspar phenocrysts.

Moore, J. G.; Sisson, T. W.

2007-12-01

 
 
 
 
221

A Survey on Intrusion Detection using Data Mining Techniques  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intrusions are the activities that violate the security policy of system. Intrusion Detection is the process used to identify intrusions. Network security is to be considered as a major issue in recent years, since the computer network keeps on extending dramatically. Information Systems and Networks are subject to electronic attacks and the possibilities of intrusion are very high.  An Intrusion Detection System (IDS) is a system for detecting intrusions and reporting to the authority or...

Venkatesan, R.

2012-01-01

222

A Distributed Network Intrusion Detection System with Active Surveillance Agent  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A distributed network intrusion detection system (IDS) called SA-NIDS is proposed based on the network-based intrusion detection architecture. It includes three basic components, Local Intrusion Detection Monitor (LIDM), Global Intrusion Detection Controller (GIDC), and Surveillance Agent (SA). Basically, the LIDM is used to do packets capturing, packets de-multiplexing, local intrusion detection and intrusion inferring. The GIDC is installed in administration center for communicating and man...

Bin Zeng; Lu Yao; Rui Wang

2013-01-01

223

Radioactivity and Geochemistry of Jasperoid Veins in Gabal Al-AGLAB Granitic Pluton, North Eastern Desert, Egypt  

International Nuclear Information System (INIS)

Al-Aglab granitic pluton hosts jasperoid as vein type mineralization. This mineralization are structurally controlled by faults and their feather joints, which are associated with NE-SW to ENE- WSW joints and micro-fractures,widespread silicification, and to a lesser extent kaolinitization and sericitization as well as other alterations accompanying the uranium mineralization. Petrologically, the studied younger granites are classified as syenogranites and texturally asperthitic leucogranites. They are originated from per aluminous, calc-alkaline, highly fractionated magma. The studied granites showed higher U and Th contents and lower Th/U ratios than those of the normal granites. They are considered as uraniferous granites originated from highly fractionated U rich magma with trapping high concentrations of uranium in the higher quotient of the radioactive accessory minerals (e.g. zircon, apatite and sphene). Uranium is concentrated at the central parts of the jasperoid veins, following the NE trend and dipping SE direction, due to their intersection with the WNW sinistral fault. Some of the anomalies are associated with visible secondary uranium minerals mainly uranophane and beta-uranophane. The high levels of radioactivity are mainly due to the high U and Th contents in jasperoid veins and the uranium content reached to 843 ppm and thorium 206 ppm. Gabal Al-Aglab uranium occurrence is considered as an example for a simple uranium vein type mineralization. It is closely associated with and restricted to the younger granite itself that affected by hydrothermal alteration. The uranium bearing late magmatic fluids could be derived from the same magma that originates the granitic pluton itself at the late stage of the magmatic activity. Geochemically, XRF and ESEM (environmental scanning electron microscope) analyses showed that Gabal Al-Aglab jasperoid veins were enriched in Th, U, Zr, W and LREE (Ce and La). The separated heavy fractions of jasperoid veins showed the presence of alunogen Al2(SO4)3.17H2O and pahasapite (Ca, Li) 11 Li 8Be 24(PO4)24.38H2O

2012-01-01

224

Zircon geochronology of Berach granite of Chittorgarh, Rajasthan  

International Nuclear Information System (INIS)

Discordant ages of zircons from Berach granite suggest that this granite crystallized around 2610 m.y. ago and lost lead during an episodic event around 710 m.y. The 710 m.y. date probably reflects a response to a regional thermal event also recorded in the 730 m.y. zircon age for the Mt. Abu 'Erinpura type' granite. (author)

1982-01-01

225

AGCM experiments on the Younger Dryas climate  

Energy Technology Data Exchange (ETDEWEB)

The Younger Dryas (YD) cooling ({proportional_to}12.5-11.5 thousand years before present) signified an interruption of the warming during the transition from the last glacial to the present interglacial. Since the mechanism responsible for this cooling is still uncertain, a numerical simulation of the YD climate has been undertaken to obtain some additional insight into this event. Three experiments with the ECHAM3 atmospheric general circulation model at T42 resolution were carried out to study the YD climate. In a first experiment only the North Atlantic surface conditions were altered according to geological evidence. In a second and third experiment additional boundary conditions were altered, as ice-sheets were introduced in North America and Scandinavia and the insolation and CO{sub 2} concentration were changed. The third simulation was identical to the second, except for an additional North Pacific cooling. The experimental outcomes were compared with that of a control simulation of present climate. The main deviations in the results were found around the North Atlantic Ocean. In the YD experiments the mean annual temperature was a few degrees lower over the continents, although the difference was larger in the vicinity of newly defined ice-sheets. An intensified atmospheric circulation was simulated. Deviations from the control climate were compared with climate reconstructions based on geological evidence. The reconstructed cooling in Europe during YD was larger than in the simulations, especially during the northern hemisphere (NH) winter. During the NH summer the reconstructions showed a large temperature gradient going inland which was consistent with the experiments. Improvements in the N-Atlantic sea surface conditions were proposed, since they were the most important factor controlling deviations. (orig.)

Renssen, H. [Netherlands Centre for Geo-Ecological Research (ICG), Utrecht (Netherlands)]|[Rijksuniversiteit Utrecht (Netherlands). Dept. of Physical Geography; Lautenschlager, M. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Bengtsson, L. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Schulzweida, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

1995-09-01

226

Episodic granite plutonism in the Scottish Caledonides  

International Nuclear Information System (INIS)

Boulders from a Lower Devonian conglomerate complete the record of a phase of Ordovician plutonism associated with island arcs and blue schist metamorphism, indicating high angle subduction. Following a phase of sedimentary accretion, late Silurian plutonism was the result of low angle subduction. The two granite suites have distinct isotopic trends. (author)

1981-05-14

227

Gamma radiation measurements in Brazilian commercial granites  

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Gamma radiation from radionuclides which are characterized by half lives comparable to the age of the earth, such as 40 K and the radionuclides from the 238 U and 232 Th series, and their decay products, represent the main terrestrial source of irradiation to the human body. Their concentrations vary for different types of rocks, where high radiation levels are associated with igneous rocks such as granite. Thorium, uranium and potassium concentrations of granitic rocks are intimately related to their mineral compositions and general petrologic features. Then, these features associated with effects of weathering and metamorphism produce expressive alterations in the relationship between the natural radionuclides (Th, U, K, Th/U and Th/K). Consequently, the measurements of thorium, uranium, and potassium concentrations of different granite samples result on individual differentiation sequences. From the 232 Th, 238 U and 40 K activity concentrations obtained for each sample, it is possible to evaluate their respective dose rates in air, when these stones are used as tiling rocks. These results are of great interest in the environmental radiological protection study, since granites are widely used as building and ornamental materials, including as indoor covering. In this way, the Laboratory of Radioecology (L.A.R.A.) of the Physics Institute of the Universidade Federal Fluminense (I.F. -U.F.F.) has been performing analyzes on more than one hundred differ ent types of the main Brazilian commercial granites in last two years [1]. Using NaI and HP Ge gamma-ray spectrometers to determine the concentration of natural radionuclides in these samples, the annual effective dose rates and the gamma activity concentration index have been evaluated and compared to the limits proposed by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and European Commission (E.C.). In addition, the correlations between thorium, uranium and potassium have been obtained with the aim of correlating the petrographic characteristics of commercial granites with their corresponding dose rates for natural radioactivity. Our results show, contrary to what some works have reported in international literature, that the Brazilian granites are not composed by minerals which could produce high levels of dose rates when used as covering material. (authors)

Anjos, R.M.; Veiga, R.; Mosquera, B.; Carvalho, C.; Macario, K. [Universidade Federal Fluminense, Niteroi (Brazil)

2006-07-01

228

Gamma radiation measurements in Brazilian commercial granites  

International Nuclear Information System (INIS)

Full text of publication follows: Gamma radiation from radionuclides which are characterized by half lives comparable to the age of the earth, such as 40 K and the radionuclides from the 238 U and 232 Th series, and their decay products, represent the main terrestrial source of irradiation to the human body. Their concentrations vary for different types of rocks, where high radiation levels are associated with igneous rocks such as granite. Thorium, uranium and potassium concentrations of granitic rocks are intimately related to their mineral compositions and general petrologic features. Then, these features associated with effects of weathering and metamorphism produce expressive alterations in the relationship between the natural radionuclides (Th, U, K, Th/U and Th/K). Consequently, the measurements of thorium, uranium, and potassium concentrations of different granite samples result on individual differentiation sequences. From the 232 Th, 238 U and 40 K activity concentrations obtained for each sample, it is possible to evaluate their respective dose rates in air, when these stones are used as tiling rocks. These results are of great interest in the environmental radiological protection study, since granites are widely used as building and ornamental materials, including as indoor covering. In this way, the Laboratory of Radioecology (L.A.R.A.) of the Physics Institute of the Universidade Federal Fluminense (I.F. -U.F.F.) has been performing analyzes on more than one hundred differ ent types of the main Brazilian commercial granites in last two years [1]. Using NaI and HP Ge gamma-ray spectrometers to determine the concentration of natural radionuclides in these samples, the annual effective dose rates and the gamma activity concentration index have been evaluated and compared to the limits proposed by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and European Commission (E.C.). In addition, the correlations between thorium, uranium and potassium have been obtained with the aim of correlating the petrographic characteristics of commercial granites with their corresponding dose rates for natural radioactivity. Our results show, contrary to what some works have reported in international literature, that the Brazilian granites are not composed by minerals which could produce high levels of dose rates when used as covering material. (authors)

2006-05-15

229

Petrology, composition, and age of intrusive rocks associated with the Quartz Hill molybdenite deposit, southeastern Alaska.  

Science.gov (United States)

A large porphyry molybdenum deposit (Quartz Hill deposit) was recently discovered in the heart of the Coast Range batholithic complex about 70 km E of Ketchikan, SE Alaska. Intrusive rocks associated with the mineral deposit form two composite epizonal to hypabyssal stocks and many dikes in country rocks. All observed metallization and alteration is within the Quartz Hill stock. Molybdenite forms fracture coatings and occurs in veins with quartz. Alteration is widespread and includes development of secondary quartz, pyrite, K-feldspar, biotite, white mica, chlorite, and zeolite. Field relations indicate that the stocks were emplaced after regional uplift and erosion of the Coast Range batholithic complex, and K-Ar data show that intrusion and alteration took place in late Oligocene time, about 27 to 30 Ma ago. Data from the Ketchikan quadrangle indicate that porphyry molybdenum metallization in the Coast Range batholithic complex is associated with regionally extensive but spotty, middle Tertiary or younger, felsic magmatism. -from Authors

Hudson, T.; Smith, J. G.; Elliott, R. L.

1979-01-01

230

Re-Os and U-Th-Pb dating of the Rochovce granite and its mineralization (Western Carpathians, Slovakia)  

Science.gov (United States)

The subsurface Rochovce granite intrusion was emplaced into the contact zone between two principal tectonic units (the Veporic Unit and the Gemeric Unit) of the Central Western Carpathians (CWC), Slovakia. The Cretaceous age of this granite and its Mo-W mineralization is shown using two independent methods: U-Pb on zircon and Re-Os on molybdenite. The studied zircons have a typical homogeneous character with oscillatory zoning and scarce restite cores. SHRIMP U-Pb data provide an age of 81.5 ± 0.7 Ma, whereas restite cores suggest a latest Neoproterozoic-Ediacaran age (~565 Ma) source. Zircon ?Hf(81) values -5.2 to + 0.2 suggest a lower crustal source, whereas one from the Neoproterozoic core ?Hf(565)= + 7.4 call for the mantle influenced old precursor. Two molybdenite- bearing samples of very different character affirm a genetic relation between W-Mo mineralization and the Rochovce granite. One sample, a quartz-molybdenite vein from the exocontact (altered quartz-sericite schist of the Ochtiná Formation), provides a Re-Os age of 81.4 ± 0.3 Ma. The second molybdenite occurs as 1-2 mm disseminations in finegrained granite, and provides an age of 81.6 ± 0.3 Ma. Both Re-Os ages are identical within their 2-sigma analytical uncertainty and suggest rapid exhumation as a consequence of post-collisional, orogen-parallel extension and unroofing. The Rochovce granite represents the northernmost occurrence of Cretaceous calc-alkaline magmatism with Mo-W mineralization associated with the Alpine-Balkan-Carpathian-Dinaride metallogenic belt.

Kohút, Milan; Stein, Holly; Uher, Pavel; Aimmerman, Aaron; Hraško, L'ubomír

2013-02-01

231

Identification of Granite Varieties from Colour Spectrum Data  

Directory of Open Access Journals (Sweden)

Full Text Available The granite processing sector of the northwest of Spain handles many varieties of granite with specific technical and aesthetic properties that command different prices in the natural stone market. Hence, correct granite identification and classification from the outset of processing to the end-product stage optimizes the management and control of stocks of granite slabs and tiles and facilitates the operation of traceability systems. We describe a methodology for automatically identifying granite varieties by processing spectral information captured by a spectrophotometer at various stages of processing using functional machine learning techniques.

José Antonio Vilán

2010-09-01

232

Identification of granite varieties from colour spectrum data.  

Science.gov (United States)

The granite processing sector of the northwest of Spain handles many varieties of granite with specific technical and aesthetic properties that command different prices in the natural stone market. Hence, correct granite identification and classification from the outset of processing to the end-product stage optimizes the management and control of stocks of granite slabs and tiles and facilitates the operation of traceability systems. We describe a methodology for automatically identifying granite varieties by processing spectral information captured by a spectrophotometer at various stages of processing using functional machine learning techniques. PMID:22163673

Araújo, María; Martínez, Javier; Ordóñez, Celestino; Vilán, José Antonio

2010-01-01

233

Rb-Sr geochronology and petrogenesis of granitoids from the Chhotanagpur granite gneiss complex of Raikera-Kunkuri region, Central India  

International Nuclear Information System (INIS)

The Precambrian Chhotanagpur granite gneiss complex (CGGC) terrain covers more than 80,000 sq km area, and is dominated by granitoid gneisses and migmatites. Recent geochronological data indicate that the CGGC terrain has witnessed five tectonomagmatic thermal events at: (i) 2.5-2.4 Ga, (ii) 2.2-2.0 Ga (iii)1.6-1.4 Ga (iv) 1.2-1.0 Ga and (v) 0.9-0.8 Ga. Of these, the third and the fourth events are widespread. The whole-rock Rb-Sr isotopic analysis of twenty granite samples from the CGGC of Raikera-Kunkuri region, Jashpur district, Chhattisgarh, Central India yields two distinct isochrons. The eleven samples of grey granites define an isochron age of 1005±51 Ma with moderate initial 87Sr/86Sr ratio of 0.7047±0.0065, which corresponds to the fourth tectonomagmatic event. On the other hand, the nine samples of pink granites indicate younger isochron age of 815±47 Ma with a higher initial 87Sr/86Sr ratio of 0.7539±0.0066 that matches with the fifth phase of the thermal event. The data suggest emplacement of large bodies of grey granite at ?1005 Ma that evolved possibly from precursors of tonalitic-granodioritic composition. Furthermore, the younger age (? 815 Ma) suggests the age of metasomatism, involving isotopic resetting, that resulted in genesis of pink granite bodies of limited areal extent. By analogy, the age of metasomatism (?815 Ma) may also be taken to represent the age of Y-mineralisation in the Raikera-Kunkuri region of the CGGC terrain. (author)

2009-08-01

234

Assessment of radiological hazard of commercial granites from Extremadura (Spain).  

Science.gov (United States)

The term "commercial granite" comprises different natural stones with different mineralogical components. In Extremadura, western Spain, "commercial granites" can be classified in three types: granite s.s. (sensus stricti), granodiorite, and diorite. The content of naturally occurring radionuclides depended of the mineralogy. Thus, the (40)K content increased as the relative content of alkaline feldspar increased but decreased as the plagioclase content increased. The radioactive content decreased in the following order: granite s.s. > granodiorite > diorite. In this work, the radiological hazard of these granites as building material was analyzed in terms of external irradiation and radon exposure. External irradiation was estimated based on the "I" index, ranged between 0.073 and 1.36. Therefore, these granites can be use as superficial building materials with no restriction. Radon exposure was estimated using the surface exhalation rates in polished granites. The exhalation rate in granites depends of their superficial finishes (different roughness). For distinct mechanical finishes of granite (polish, diamond sawed, bush-hammered and flamed), the surface exhalation rate increased with the roughness of the finishes. Thermal finish presented the highest exhalation rate, because the high temperatures applied to the granite may increase the number of fissures within it. The exhalation rates in polished granites varied from 0.013 to 10.4 Bq m(-2) h(-1). PMID:24583635

Guillén, J; Tejado, J J; Baeza, A; Corbacho, J A; Muñoz, J G

2014-06-01

235

Signature Based Intrusion Detection System Using SNORT  

Directory of Open Access Journals (Sweden)

Full Text Available Now a day’s Intrusion Detection systems plays very important role in Network security. As the use of internet is growing rapidly the possibility of attack is also increasing in that ratio. People are using signature based IDS’s. Snort is mostly used signature based IDS because of it is open source software. World widely it is used in intrusion detection and prevention domain. Basic analysis and security engine (BASE is also used to see the alerts generated by Snort. In the paper we have implementation the signature based intrusion detection using Snort. Our work will help to novel user to understand the concept of Snort based IDS.

Vinod Kumar

2012-11-01

236

Advanced technologies for perimeter intrusion detection sensors  

Energy Technology Data Exchange (ETDEWEB)

The development of integrated circuit fabrication techniques and the resulting devices have contributed more to the advancement of exterior intrusion detectors and alarm assessment devices than any other technology. The availability of this technology has led to the improvements in and further development of smaller more powerful computers, microprocessors, solid state memories, solid state cameras, thermal imagers, low-power lasers, and shorter pulse width and higher frequency electronic circuitry. This paper presents information on planning a perimeter intrusion detection system, identifies the site characteristics that affect its performance, and describes improvements to perimeter intrusion detection sensors and assessment devices that have been achieved by using integrated circuit technology.

Williams, J.D.

1995-03-01

237

A Novel Approach for Intrusion Detection  

Directory of Open Access Journals (Sweden)

Full Text Available Research in the field of computer and network science demands for tools and methodology to test their security effectively. Intrusion Detection System is used to perform the same with a fact that an intruder's behavior will be noticeably different from that of a legitimate user and would exploit security vulnerabilities. Proposed here is a novel intrusion detection approach with the application of Generalized Regression Neural Network and the MIT's KDD Cup 99 dataset. The result clearly demonstrates an efficient way for intrusion feature selection and detection and promises a good scope for further research.

Vikram Chopra

2011-07-01

238

Effect of Bacillus subtilis on Granite Weathering: A Laboratory Experiment  

Science.gov (United States)

We performed a comparative experiment to investigate how the ubiquitous soil bacterium Bacillus subtilis weathers granite and which granite-forming minerals weather more rapidly via biological processes. Batch type experiments (granite specimen in a 500 ml solution including NaCl, glucose, yeast extract and bacteria Bacillus subtilis at 27°E C) were carried out for 30 days. Granite surfaces were observed by SEM before and after the experiment. Bacillus subtilis had a strong influence on granite weathering by forming pits. There were 2.4 times as many pits and micropores were 2.3 times wider in granite exposed to Bacillus subtilis when compared with bacteria-free samples. Bacillus subtilis appear to preferentially select an optimum place to adhere to the mineral and dissolve essential elements from the mineral to live. Plagioclase was more vulnerable to bacterial weathering than biotite among the granite composing minerals.

Song, W.; Ogawa, N.; Oguchi, C. T.; Hatta, T.; Matsukura, Y.

2006-12-01

239

Granite suites and supersuites of eastern Australia  

International Nuclear Information System (INIS)

Separate granite plutons in southeastern Australia can commonly be grouped into suites on the basis of shared similarities in field, petrographic and compositional data. Granites in different plutons of the same suite share common properties or exhibit a sequence of such features Rocks of the same suite are co genetic, but the details of their genesis need not be known or agreed on, to group granite units in such a way. These rocks are co genetic in the sense that they shared a similar petrogenesis and were derived from source materials of essentially the same composition, whereas differences between suites reflect analogous differences in their source rocks. The term suite is lithologic or lithodemic in a stratigraphic sense and is closely analogous to the lithostratigraphic term group As such, the plutons within a suite need not be of the same age, and age is not a factor in recognising a suite. However, the fact that the petrogenesis of the components of a suite resulted in such similar products means that their ages are likely to be similar Granite plutons that share many similar features, but which also show distinct differences and which may be assigned to more than one suite, may be grouped into supersuites. The allocation of granites to suites is fundamental to understanding their petrogenesis. Suites vary in the complexity of their compositional variation. Simple suites show variations in element abundances that are highly correlated and the dispersion of composition within such suites is considered to result from varying degrees of fractionation of entrained restite from a melt. Intricate suites vary in composition in more complex ways and their variation is considered to be a consequence of processes such as fractional crystallisation. Any mineralisation is generally associated with intricate suites, and the occurrence of mineralisation and its precise character is generally specific to particular suites. If isotopic compositional dispersion within a granite suite is observed, a process of magma mixing or mingling is commonly invoked. A particular case where isotopic dispersion would occur is that when a mantle-derived component partly melts and then mingles with a crustal magma (Barbarin 1991); the more felsic rocks would be isotopically more evolved than the mafic ones. Granite derived from heterogeneous source rocks, particularly granites formed from relatively low degrees of partial melting from metasedimentary rocks, might be expected to reflect that lack of isotopic uniformity in their source compositions. For example, Chappell et al. (1999) noted that the initial 87Sr/86Sr values for 10 granites sampled from various parts of the Jillamatong pluton show a range of 0.0039, approximately 50-fold that of analytical uncertainty. For this very mafic unit of the S-type Bullenbalong Suite, there is no systematic variation of strontium isotopic composition with SiO2, although samples of more felsic members of the Bullenbalong Suite and Supersuite show a systematic decrease in initial 87Sr/86Sr with increase in SiO2. This observation indicates that variation in initial isotope ratios is here source related, and not magma-mingling related. Copyright (2001) Geological Society of Australia

2001-08-01

240

The Younger Dryas impact hypothesis: A requiem  

Science.gov (United States)

The Younger Dryas (YD) impact hypothesis is a recent theory that suggests that a cometary or meteoritic body or bodies hit and/or exploded over North America 12,900 years ago, causing the YD climate episode, extinction of Pleistocene megafauna, demise of the Clovis archeological culture, and a range of other effects. Since gaining widespread attention in 2007, substantial research has focused on testing the 12 main signatures presented as evidence of a catastrophic extraterrestrial event 12,900 years ago. Here we present a review of the impact hypothesis, including its evolution and current variants, and of efforts to test and corroborate the hypothesis. The physical evidence interpreted as signatures of an impact event can be separated into two groups. The first group consists of evidence that has been largely rejected by the scientific community and is no longer in widespread discussion, including: particle tracks in archeological chert; magnetic nodules in Pleistocene bones; impact origin of the Carolina Bays; and elevated concentrations of radioactivity, iridium, and fullerenes enriched in 3He. The second group consists of evidence that has been active in recent research and discussions: carbon spheres and elongates, magnetic grains and magnetic spherules, byproducts of catastrophic wildfire, and nanodiamonds. Over time, however, these signatures have also seen contrary evidence rather than support. Recent studies have shown that carbon spheres and elongates do not represent extraterrestrial carbon nor impact-induced megafires, but are indistinguishable from fungal sclerotia and arthropod fecal material that are a small but common component of many terrestrial deposits. Magnetic grains and spherules are heterogeneously distributed in sediments, but reported measurements of unique peaks in concentrations at the YD onset have yet to be reproduced. The magnetic grains are certainly just iron-rich detrital grains, whereas reported YD magnetic spherules are consistent with the diffuse, non-catastrophic input of micrometeorite ablation fallout, probably augmented by anthropogenic and other terrestrial spherular grains. Results here also show considerable subjectivity in the reported sampling methods that may explain the purported YD spherule concentration peaks. Fire is a pervasive earth-surface process, and reanalyses of the original YD sites and of coeval records show episodic fire on the landscape through the latest Pleistocene, with no unique fire event at the onset of the YD. Lastly, with YD impact proponents increasingly retreating to nanodiamonds (cubic, hexagonal [lonsdaleite], and the proposed n-diamond) as evidence of impact, those data have been called into question. The presence of lonsdaleite was reported as proof of impact-related shock processes, but the evidence presented was inconsistent with lonsdaleite and consistent instead with polycrystalline aggregates of graphene and graphane mixtures that are ubiquitous in carbon forms isolated from sediments ranging from modern to pre-YD age. Important questions remain regarding the origins and distribution of other diamond forms (e.g., cubic nanodiamonds). In summary, none of the original YD impact signatures have been subsequently corroborated by independent tests. Of the 12 original lines of evidence, seven have so far proven to be non-reproducible. The remaining signatures instead seem to represent either (1) non-catastrophic mechanisms, and/or (2) terrestrial rather than extraterrestrial or impact-related sources. In all of these cases, sparse but ubiquitous materials seem to have been misreported and misinterpreted as singular peaks at the onset of the YD. Throughout the arc of this hypothesis, recognized and expected impact markers were not found, leading to proposed YD impactors and impact processes that were novel, self-contradictory, rapidly changing, and sometimes defying the laws of physics. The YD impact hypothesis provides a cautionary tale for researchers, the scientific community, the press, and the broader public.

Pinter, Nicholas; Scott, Andrew C.; Daulton, Tyrone L.; Podoll, Andrew; Koeberl, Christian; Anderson, R. Scott; Ishman, Scott E.

2011-06-01

 
 
 
 
241

A New Method for Intrusion Detection using Manifold Learning Algorithm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Computer and network security has received and will still receive much attention. Any unexpected intrusion will damage the network. It is therefore imperative to detect the network intrusion to ensure the normal operation of the internet. There are many studies in the intrusion detection and intrusion patter recognition. The artificial neural n...

Guoping Hou; Xuan Ma; Yuelei Zhang

2013-01-01

242

STATISTICAL TECHNIQUES IN ANOMALY INTRUSION DETECTION SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we analyze an anomaly based intrusion detection system (IDS for outlier detection in hardware profile using statistical techniques: Chi-square distribution, Gaussian mixture distribution and Principal component analysis. Anomaly detection based methods can detect new intrusions but they suffer from false alarms. Host based Intrusion Detection Systems (HIDSs use anomaly detection to identify malicious attacks i.e. intrusion. The features are shown by large set of dimensions and the system becomes extremely slow during processing this huge amount of data (especially, host based. We show the comparative results using three different approaches: Principal Component Analysis (PCA, Chi-square distribution and cluster with Gaussian mixture distribution. We get good results using these techniques.

Hari Om

2012-11-01

243

Perimeter intrusion detection and assessment system  

Energy Technology Data Exchange (ETDEWEB)

The key elements of the system considered at a materials storage site are intrusion sensors, alarm assessment, and system control and display. Three papers discussing each of these topics are compiled. They are abstracted individually. (JSR)

Eaton, M.J.; Jacobs, J.; McGovern, D.E.

1977-01-01

244

Policies Based Intrusion Response System for DBMS  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion detection systems play an important role in detectingonline intrusions and provide necessary alerts. Intrusion detectioncan also be done for relational databases. Intrusion responsesystem for a relational database is essential to protect it fromexternal and internal attacks. We propose a new intrusionresponse system for relational databases based on the databaseresponse policies. We have developed an interactive languagethat helps database administrators to determine the responses tobe provided by the response system based on the maliciousrequests encountered by relational database. We also maintain apolicy database that maintains policies with respect to responsesystem. For searching the suitable policies algorithms aredesigned and implemented. Matching the right policies andpolicy administration are the two problems that are addressed inthis paper to ensure faster action and prevent any maliciouschanges to be made to policy objects. Cryptography is also usedin the process of protecting the relational database from attacks.The experimental results reveal that the proposed responsesystem is effective and useful.

Fatima Nayeem

2012-12-01

245

Intrusion Detection System Using Advanced Honeypots  

CERN Multimedia

The exponential growth of Internet traffic has made public servers increasingly vulnerable to unauthorized accesses and intrusions. In addition to maintaining low latency for the client, filtering unauthorized accesses has become one of the major concerns of a server maintainer. This implementation of an Intrusion Detection System distinguishes between the traffic coming from clients and the traffic originated from the attackers, in an attempt to simultaneously mitigate the problems of both latency and security. We then present the results of a series of stress and scalability tests, and suggest a number of potential uses for such a system. As computer attacks are becoming more and more difficult to identify the need for better and more efficient intrusion detection systems increases. The main problem with current intrusion detection systems is high rate of false alarms. Using honeypots provides effective solution to increase the security.

Singh, Ram Kumar

2009-01-01

246

Intrusion Detection Architecture Utilizing Graphics Processors  

Directory of Open Access Journals (Sweden)

Full Text Available With the thriving technology and the great increase in the usage of computer networks, the risk of having these network to be under attacks have been increased. Number of techniques have been created and designed to help in detecting and/or preventing such attacks. One common technique is the use of Intrusion Detection Systems (IDS. Today, number of open sources and commercial IDS are available to match enterprises requirements. However, the performance of these systems is still the main concern. This paper examines perceptions of intrusion detection architecture implementation, resulting from the use of graphics processor. It discusses recent research activities, developments and problems of operating systems security. Some exploratory evidence is presented that shows capabilities of using graphical processors and intrusion detection systems. The focus is on how knowledge experienced throughout the graphics processor inclusion has played out in the design of intrusion detection architecture that is seen as an opportunity to strengthen research expertise.

Branislav Madoš

2012-12-01

247

A phased approach to network intrusion detection  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the design and development of a prototype intrusion detection system for the Los Alamos National Laboratory's Integrated Computing Network (ICN). The development of this system is based on three basic assumptions: (1) that statistical analysis of computer system and user activates may be used to characterize normal system and user behavior, and that given the resulting statistical profiles, behavior which deviates beyond certain bounds can be detected, (2) that expert system techniques can be applied to security auditing and intrusion detection, and (3) that successful intrusion detection may take place while monitoring a limited set of network activities. The Network Anomaly Detection and Intrusion Reporter (NADIR) design intent was to duplicate and improve the audit record review activities which had previously been undertaken by security personnel, to replace the manual review of audit logs with a near realtime expert system.

Jackson, K.A.; DuBois, D.H.; Stallings, C.A.

1991-01-01

248

Performance assessment of geological isolation systems for radioactive waste. Disposal in granite formations  

International Nuclear Information System (INIS)

In the framework of the PAGIS project of the CEC Research Programme on radioactive wastes, a performance assessment of a repository of vitrified HLW in granite was carried out. Three disposal sites were considered: the reference site Auriat and two alternative sites, Barfleur and a site in the U.K. The report describes the methodology adopted (a deterministic and a stochastic approach) with the corresponding data base and the models used. A parametric study of sub-systems (near field, far field and biosphere) was carried out by CEA-ANDRA using AQUARIUS, DIMITRIO and BIOS. A global evaluation of the performances was carried out by CEA-IPSN using MELODIE code. The results of deterministic calculations showed for Auriat a maximum dose equivalent evaluated at 6.10-3m Sv/a arising 3 millions years after disposal. Results of human intrusion scenario analyses, uncertainty analyses and global sensitivity analyses are presented. This document is one of a set of 5 reports covering a relevant project of the European Community on a nuclear safety subject having very wide interest. The five volumes are: the summary (EUR 11775-EN), the clay (EUR 11776-EN), the granite (EUR 11777-FR), the salt (EUR 11778-EN) and the sub-seabed (EUR 11779-EN)

1988-01-01

249

Using Jquery with Snort to Visualize Intrusion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The explosive growth of malicious activities on worldwide communication networks, such as the Internet, has highlighted the need for efficient intrusion detection systems. The efficiency of traditional intrusion detection systems is limited by their inability to effectively relay relevant information due to their lack of interactive / immersive technologies. Visualized information is a technique that can encode large amounts of complex interrelated data, being at the same time easily quantifi...

Alaa El - Din Riad; Ibrahim Elhenawy; Ahmed Hassan; Nancy Awadallah

2012-01-01

250

Intrusion problematic during water supply systems’ operation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intrusion through leaks occurrence is a phenomenon when external fluid comes into water pipe systems. This phenomenon can cause contamination problems in drinking pipe systems. Hence, this paper focuses on the entry of external fluids across small leaks during normal operation conditions. This situation is especially important in elevated points of the pipe profile. Pressure variations can origin water volume losses and intrusion of contaminants into the drinking water pipes. This work focuse...

Jesus Mora-rodriguez, P. Amparo Lo?pez-jimenez

2011-01-01

251

Improving Intrusion Detection Using Genetic Algorithm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Intrusion Detection System (IDS) is one of the key security components in today’s networking environment. A great deal of attention has been recently paid to anomaly detection to accomplish intrusion detection. However, a major problem with this approach is maximizing detection rate and accuracy, as well as minimizing false alarm i.e., inability to correctly discover particular types of attacks. To overcome this problem, a genetic algorithm approach is proposed. Genetic Algorithm (GA) is mo...

Moraveji Hashemi, V.; Muda, Z.; Yassin, W.

2013-01-01

252

Unsupervised Genetic Algorithm Deployed for Intrusion Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper represents the first step in an on-going work for designing an unsupervised method based on genetic algorithm for intrusion detection. Its main role in a broader system is to notify of an unusual traffic and in that way provide the possibility of detecting unknown attacks. Most of the machinelearning techniques deployed for intrusion detection are supervised as these techniques are generally more accurate, but this implies the need of labeling the data for training and testing whic...

Bankovic, Zorana; Bojanic, Slobodan; Nieto-taladriz Garci?a, Octavio; Badii, Atta

2008-01-01

253

A Novel Approach for Intrusion Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Research in the field of computer and network science demands for tools and methodology to test their security effectively. Intrusion Detection System is used to perform the same with a fact that an intruder's behavior will be noticeably different from that of a legitimate user and would exploit security vulnerabilities. Proposed here is a novel intrusion detection approach with the application of Generalized Regression Neural Network and the MIT's KDD Cup 99 dataset. The result clearly demon...

Vikram Chopra; Sunil Saini; Amit Kumar Choudhary

2011-01-01

254

Mobile Agents in Intrusion Detection System: Review and Analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion Detection System (IDS is used to detect intrusion and then alert the system administrator about the intrusion. This is what traditional IDS is all about. It is then up to the system administrator to deal with the intrusion. Human intervention is still needed when it comes to dealing with intrusion. This is because traditional IDS could only detect the intrusion but could not, on its own respond towards the intrusion. IDS is only able to alert the system administrator when it detects an intrusion. How and when the intrusion is dealt with is up to the system administrator. Human intervention when dealing with intrusion is not a problem if the person assigned to that task is always reliable. Therefore, this paper analyzes the evolution of IDS and how mobile agents such as SNORT could increase the integrity of traditional systems without human intervention.

Kamaruzaman Maskat

2011-11-01

255

Cluster based Intrusion Detection System for Manets  

Directory of Open Access Journals (Sweden)

Full Text Available Manets are the ad hoc networks that are build on demand or instantly when some mobile nodes come in the mobility range of each other and decide to cooperate for data transfer and communication. Therefore there is no defined topology for Manets. They communicate in dynamic topology which continuously changes as nodes are not stable. Due to this lack of infrastructure and distributed nature they are more vulnerable for attacks and provide a good scope to malicious users to become part of the network. To prevent the security of mobile ad hoc networks many security measures are designed such as encryption algorithms, firewalls etc. But still there is some scope of malicious actions. So, Intrusion detection systems are proposed to detect any intruder in the network and its malicious activities. Cluster based intrusion detection system is also designed to restrict the intruders activities in clusters of mobile nodes. In clusters each node run some intrusion detection code to detect local as well as global intrusion. In this paper we have taken insight of intrusion detection systems and different attacks on Manet security. Then we proposed how overhead involved in cluster based intrusion detection system can be reduced.

Nisha Dang

2012-07-01

256

Network Intrusion Detection using Support Vector Regression  

Directory of Open Access Journals (Sweden)

Full Text Available Data Mining is the use of algorithms to extract the information and patterns derived by the knowledge discovery in databases process. Classification maps data into predefined groups or classes. It is often referred to as supervised learning because the classes are determined before examining the data. This paper addresses using ensemble approach of Support Vector Regression for intrusion detection. Due to increasing incidents of cyber attacks, building effective intrusion detection systems (IDS are essential for protecting information systems security, and yet it remains an elusive goal and a great challenge. The feasibility and the benefits of the proposed approach are demonstrated by means of data mining problem: Network Intrusion Detection. Intrusion detection systems help network administrators prepare for and deal with network security attacks. These systems collect information from a variety of systems and network sources, and analyze them for signs of intrusion and misuse.  We show that proposed ensemble of Support Vector Regression is superior to individual approach for intrusion detection in terms of classification rate.

Govindarajan Muthukumarasamy

2011-04-01

257

Diffusion interfaces of fractures in granitic rocks  

International Nuclear Information System (INIS)

The report presents a method to describe pore space around the major fractures in granitic rocks. The method is based on conventional technique, such as microscopy, porosity measurements and chemical analyses. The results are presented as profiles perpendicular to the fracture surface. Two types of open fracture and a partially filled carbonate fracture. In the examined cases, about 80 - 90 % of the range of variations in porosity and chemical contents were related to the first 4 - 5 mm from the fracture surface into the rock matrix. Porosity of the interface was decreased down to the reported average porosity of granites (5.2 - 0.4 % vol) within 10 - 20 mm from the fracture surface. Porosity profiles were not, however, completely stabilized within this distance. The marked trends in chemical profiles are caused by both deformation history of the rock and recent interaction between rock and water in pore space. Porosity and geochemical profiles are observed fracture specific

1990-01-01

258

Sorption of U(VI) on granite  

International Nuclear Information System (INIS)

The sorption-desorption of U(VI) on granite was studied using a batch technique. The sorption coefficients varied between 8.0 and 0.4 ml/g and sorption was not fully reversible. The data could be fitted to a Freundlich isotherm. By fitting the data with the Dubinin-Radushkevich equation, a mean energy of sorption of 10.7 kJ/mol was calculated, which corresponds to the energy of ion exchange reactions. The kinetic data could be interpreted by assuming diffusion into the crushed granite particles. The calculated pore diffusion coefficient was between 2.0 · 10-11-7.7 · 10-11 m2/s. (author) 34 refs.; 4 figs

1989-01-01

259

Les granites varisques du Massif Armoricain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Un important magmatisme intrusif a affecté le massif armoricain entre la fin du Dévonien et le début du Permien. Ce plutonisme a été décrit dans le passé sur la base de différents critères. Nous le présentons ici pour la première fois sur la seule base pétro-géochimique. Ce seul critère permet de mettre en évidence 5 associations plutoniques de nature et d'origine différentes. 1) Une association calco-alcaline allant des gabbros aux granites à biotite et hornblende, de compos...

Capdevila, Ramon

2010-01-01

260

Comparison of specularly reflecting mirrors for GRANIT  

International Nuclear Information System (INIS)

The specularity of ultracold neutron reflection was compared for different 'promising' surfaces, including sapphire, silica, silica with carbon (diamond-like), and copper coatings with very small roughness. The probability of total losses of ultracold neutrons (UCN) from a specular trajectory was dominated by diffusive (non-specular) elastic scattering of UCN. In all the cases considered the quality of reflection was sufficiently high for storage of UCN at specular trajectories for the first stage of GRANIT experiment

2007-08-01

 
 
 
 
261

Radioactivity of some imported granite and marble  

International Nuclear Information System (INIS)

The results of gamma spectrometry analysis of some imported marble and granite samples are presented. The measurements were provided by HP Ge detector and multichannel analyzer, using Genie 2000 software. Activities of radionuclides in the examined samples are found in the range that gives gamma index below 1 (except in two cases), so that these materials can be used at indoor and outdoor building construction. (author)

2007-09-01

262

Geochronological and geochemical study of the Pan African intrusive rocks along the Najd Fault system in El Wajh area, Saudi Arabia  

Science.gov (United States)

In the active tectonic regions, shear zones play an important role to re-configure the structure of the lithosphere. One of the largest shear zones on the Earth is the Najd Fault system of the Arabian-Nubian Shield. Literature data record the main active phase of this shear zone during the last stages of the Pan-African Orogeny (ca. 650-550 Ma). Compilation of new geochronological and geochemical data in addition to field relation is used to figure the tectonic history of the Najd Fault system. Different relationships between igneous intrusions and the Najd Fault System are observed. Some igneous bodies predate the activity of the shear zone, others intruded during the shearing process and a later phase intruded after the activity of the Najd Fault system ceased. The intrusive rocks in the study area show a geochemical and compositional diversity. Intrusives with dioritic composition were derived from a metaluminous tholeiitic magma around 700 Ma, and granodiorite-tonalite intrusions have calcalkaline characters and display a metaluminous to peraluminous character (ca. 740 and 660 Ma) then the magmatic activity terminated with peraluminous calcalkaline intrusives which formed granitic rocks with intrusion ages of 605-580 Ma. These magmatic events are identical for the Arabian-Nubian Shield but contamination from the crust or different rates of fractionation are recorded in our samples which are responsible for variations in the geochemical signature of the intrusive rocks. Based on field observations and contact relations, the intrusive rocks within the Ajjaj shear zone were studied in details in order to determine the age and the tectonic history of this shear zone that marks the termination of the Najd System against the eastern margin of the Red Sea. The provided zircon U-Pb dating by LA-ICP-MS and field relationships confine the activation age of the Ajjaj shear zone in limited period between 605 Ma and 580 Ma.

Hassan, Mahmoud; Abu-Alam, Tamer; Hauzenberger, Christoph; Stüwe, Kurt; Tiepolo, Massimo

2014-05-01

263

Diffusion of uranium in the granite rock  

International Nuclear Information System (INIS)

In the safety assessment of high level radioactive waste disposal, a significant retardation factor of radionuclides leaking from an underground repository can be expected. When radionuclides released from an underground repository are transported with the moving groundwater along cracks in the rock, the radionuclides will be retarded by not only adsorption on the surface of the cracks but also by process diffusion into submicron pores of rock matrix. In this experiments have been performed by process diffusion of uranium in water saturated granite. The measured penetration profile of uranium was composed of two parts. This profile was successfully explained by considering two diffusion paths in granite rock. One diffusion path was possibly a fissure with a width of few microns and another was a submicron pores of granite rock. The orders of magnitude of diffusivities for uranium were 10"-"1"2 m"2/sec through the fissure and 10"15 m"2/sec through the submicron pores. The difference between the diffusivities of two path is thought to be caused by small geometrical factor of submicron pores, if to compared with fissures. (author)

1996-06-01

264

SILICOSIS FROM QUARRYING AND WORKING OF GRANITE  

Science.gov (United States)

Previous knowledge of silicosis in the Swedish granite industry suggested that the disease was neither common nor severe. In recent years, however, changes in working methods have involved a considerably increased formation of dust, and it was considered likely that the risk of contracting silicosis was increased. Reports from other countries supported this conjecture. The 34 known cases of silicosis caused by quarrying and working of granite in Sweden were therefore reviewed. The mean duration of exposure to siliceous dust when stage I silicosis was diagnosed was 32 years, and the mean age at diagnosis was 55 years. Despite the relatively long `prediagnosis' exposure to dust, the disease showed a pronounced tendency to progression, and six cases were complicated by pulmonary tuberculosis. Eighty per cent of the men were awarded disablement benefit because of their pulmonary lesions, and four men died from silicosis alone or in combination with tuberculosis. In Swedish granite works there is room for considerable improvement in dust suppression. Careful checks of such preventive measures and periodic medical examination of exposed persons are strongly advocated.

Ahlmark, A.; Bruce, T.; Nystrom, A

1965-01-01

265

Zircon U-Pb and Hf-Nd isotopic constraints on the genesis of granites from the vicinity of Bosumtwi crater  

Science.gov (United States)

The well preserved Bosumtwi crater (Ghana), 10.5 km in diameter and 1.07 Myr old (e.g., Koeberl and Reimold 2005), was excavated in rocks of the Early Proterozoic Birimian Supergroup. These rocks were deposited 2.1-2.15 Gyr ago in a volcanic arc environment and were metamorphosed to greenschist facies during the Eburnean tectono-thermal event (e.g., Jones et al. 1981, Feybesse et al. 2006). The Birimian Supergroup mainly consists of two contemporary units: volcanic belts and sedimentary basins aligned in multiple parallel features. Additionally, numerous granitoid intrusions were emplaced within the Birimian Supergroup (Wright et al. 1985). Two main types of granitoid intrusions are recognized in Ghana: belt granitoids and basin granitoids (Leube et al. 1990). Both types can be distinguished according to petrology, chemistry, and age. Whereas previous studies of target rocks from the Bosumtwi crater focused on metasedimentary rocks (e.g., Karikari et al. 2007), in this study we investigate felsic intrusive bodies. This work will also provide more data on the geological evolution of the Kumasi basin and Ashanti belt regions in Ghana. We analyzed thirteen samples for their major- and trace element compositions, as well as their U-Pb, Lu-Hf, and Sm-Nd systematics. Twelve samples come from three different felsic intrusive bodies. Two intrusions are located to the north of the crater, previously described as basin-type granitoids, whereas one intrusion was classified as belt-type granite (Koeberl and Reimold 2005). One sample represents a mafic (diabase) dyke. Analyses were performed using optical microscopy, XRF, and INAA at the University of Vienna, as well as by MC-ICPMS at the University of Bonn. Additional zircon U-Pb ages were obtained with VG Sector-54 multicollector TIMS at the Massachusetts Institute of Technology. Zircon ages for samples from four different intrusive bodies vary within a narrow range between 2091.96 ± 7 Ma and 2097.70 ± 7 Ma. A whole-rock 147Sm-143Nd regression line, defined by six samples coming from all sampled bodies, correlates to an age of 2048±63 Ma, in accordance with the U-Pb data for zircons. Notably, a sample from a mafic intrusion plots also on the regression line. Whole-rock 176Lu-176Hf data define a regression line yielding no meaningful geological age, possibly due to inherited old zircons from the source. Our first results suggest that, despite previous research (Koeberl and Reimold 2005), all studied intrusions genetically belong to the basin-type intrusions. All intrusions share common geochemical and petrologic properties, and were emplaced at approximately the same time.

Losiak, A.; Schulz, T.; Koeberl, C.

2012-04-01

266

Transition from oceanic to continental lithosphere subduction in southern Tibet: Evidence from the Late Cretaceous–Early Oligocene (~ 91–30 Ma) intrusive rocks in the Chanang–Zedong area, southern Gangdese  

Science.gov (United States)

Little is known about the detailed processes associated with the transition from oceanic to continental lithosphere subduction in the Gangdese Belt of southern Tibet (GBST). Here, we report zircon U–Pb age, major and trace element and Sr–Nd–Hf isotopic data for Late Cretaceous–Early Oligocene (~ 91–30 Ma) intermediate-acid intrusive rocks in the Chanang–Zedong area immediately north of the Yarlung–Tsangpo suture zone. These rocks represent five magmatic episodes at ~ 91, ~ 77, ~ 62, ~ 48, and ~ 30 Ma, respectively. The 91–48 Ma rocks have slightly lower initial 87Sr/86Sr (0.7037 to 0.7047), and higher ?Nd(t) (+ 1.8 to + 4.3) and ?Hf(t) (+ 3.5 to + 14.7) values in comparison with those (0.7057 to 0.7062, ? 3.3 to ? 2.5 and + 2.2 to + 6.6) of the ~ 30 Ma intrusive rocks. The ~ 91, ~ 62 and ~ 30 Ma rocks are geochemically similar to slab-derived adakites. The ~ 91 Ma Somka adakitic granodiorites were likely derived by partial melting of the subducting Neo-Tethyan oceanic crust with minor oceanic sediments, and the ~ 91 Ma Somka dioritic rocks with a geochemical affinity of adakitic magnesian andesites likely resulted from interactions between adakitic magmas and overlying mantle wedge peridotite. The ~ 77 Ma Luomu diorites were probably generated by partial melting of juvenile basaltic lower crust. The ~ 62 Ma Naika and Zedong adakitic diorites and granodiorites were likely generated mainly by partial melting of thickened juvenile mafic lower crust but the source region of the Zedong adakitic rocks also contained enriched components corresponding to Indian continental crust. The ~ 48 Ma Lamda granites were possibly generated by melting of a juvenile basaltic crust. The younger (~ 30 Ma) Chongmuda adakitic quartz monzonites and minor granodiorites were most probably derived by partial melting of Early Oligocene northward-subducted Indian lower crust beneath the southern Lhasa Block. Taking into account the regional tectonic and magmatic data, we suggest that the Gangdese Belt of southern Tibet (GBST) underwent a tectonodynamic transition from oceanic subduction to continental subduction between 100 and 30 Ma. It evolved through four stages: 100–65 Ma roll-back of subducted Neo-Tethyan oceanic lithosphere; 65–60 Ma initial collision between Indian and Asian continents; 60–40 Ma breakoff of subducted Neo-Tethyan oceanic lithosphere; and ~ 30 Ma northward subduction of the Indian continent.

Jiang, Zi-Qi; Wang, Qiang; Wyman, Derek A.; Li, Zheng-Xiang; Yang, Jin-Hui; Shi, Xiao-Bing; Ma, Lin; Tang, Gong-Jian; Gou, Guo-Ning; Jia, Xiao-Hui; Guo, Hai-Feng

2014-05-01

267

U-Th-Pb systematics in hydrothermally altered granites from the Granite Mountains, Wyoming  

International Nuclear Information System (INIS)

U-Th-Pb systematics were investigated in 15 samples representing two types of deuterically altered Archean granite from Wyoming. The loss of K-feldspar during both types of deuteric alteration was accompanied by an extreme reduction of Pb content from roughly 40 ppm to less than 12 ppm in the most altered samples. Nine of the 15 samples yield anomalously young whole-rock Pb-Pb and Th-Pb ages compared to concordia ages for zircons and to whole-rock Pb-Pb and Th-Pb ages for samples of unaltered granite. The young ages are interpreted to be the result of radiogenic Pb loss during a middle Proterozoic metamorphism that disturbed several isotopic systems in the unaltered granite. The results are discussed. (author)

1981-01-01

268

Natural radioactivity of granites used as building materials  

International Nuclear Information System (INIS)

Sixteen kinds of different granites, used as building materials, imported to Greece mainly from Spain and Brazil, were sampled and their natural radioactivity was measured by gamma-ray spectrometry. The activity concentrations of 238U, 226Ra, 232Th and 4K of granites are presented and compared to those of other building materials as well as other granite types used all over the world. In order to assess the radiological impact from the granites investigated, the absorbed and the effective doses were determined. Although the annual effective dose is higher than the limit of 1 mSv y-1 for some studied granites, they could be used safely as building materials, considering that their contribution in most of the house constructions is very low. An attempt to correlate the relatively high level of natural radioactivity, shown by some of the granites, with their constituent radioactive minerals and their chemical composition, was also made

2006-01-01

269

Novel Approach for Hybrid Intrusion Detection System  

Directory of Open Access Journals (Sweden)

Full Text Available This Paper titled “Novel Approach for Intrusion Detection System” is an intrusion detection system (IDS proposed by analyzing the principle of the intrusion detection system based on host and network. Basically this paper is to develop host based cum network based intrusion detection system for Microsoft Windows XP environment. Proposed concept that had used in this was applying intrusion detection rule matching technique on the Security Log File and Event Log File in Microsoft Windows XP for the Host based IDS module. The intrusion had identified when there was finding of attacks that is creating with these two file in Microsoft Windows XP. In Network based IDS module DOS, U2R, Rejected (RST attacks are finding during packet capturing in network. Moreover, the security and performance of the proposed IDS is also estimated. The proposed IDS approve the effectiveness of the proposed method, and it shows advantages of host based as well as network based security. The proposed model of hybrid IDSs offers several advantages over alternative systems. First of all it provided higher security, it supported high availability and scalability, and most important thing it produced good results in terms of normal and abnormal behaviors of arrived packet. The proposed model includes integration of individual components to produced batter results. It supports to a system/network administrator the privileges for finding the intrusions which is reliable, secure and fast. The proposed model of hybrid IDS implemented in short time and at a low cost. It also provides a best user interface.

Ravi Kishore Sharma, Mr. Gajendra Singh Chandel

2012-11-01

270

The Phalaborwa Syenite Intrusions along the West-Central Boundary of the Kruger National Park  

Directory of Open Access Journals (Sweden)

Full Text Available The geology of the Phalaborwa Complex is described and emphasis placed on the distribution of the large number of syenite intrusions. The petrography of the different textural types of syenites is discussed and it is shown that porphyritic, granular, gneissic and hypidiomorphic syenites are present. The petrography shows that the deformation textures, which are present in some of the syenites, may have formed during the emplacement of syenitic magmas which contained a high concentration of crystals. The geochemistry of the syenites is discussed and it is shown that they were not derived from an alkali basaltic magma through fractional crystallisation, but that they may rather represent alkali basaltic magmas which were contaminated by granitic material. The mode of emplacement of the Phalaborwa Complex is discussed and the relationship between the pyroxenites is explained.

C. Frick

1986-12-01

271

Younger Adults' Communication Experiences and Contact with Elders and Peers.  

Science.gov (United States)

Surveys 100 younger adults' satisfying/dissatisfying experiences with elders, comparing them with peers. Finds positivity of experiences and contact increased from nonfamily to family elders and to peers. (PA)

Ng, Suk Hung; Liu, James H.; Weatherall, Ann; Loong, Cynthia S. F.

1997-01-01

272

Younger Blacks on Dialysis Fare Worse in Poor Neighborhoods  

Science.gov (United States)

... this page, please enable JavaScript. Younger Blacks on Dialysis Fare Worse in Poor Neighborhoods: Study Racial difference ... 16, 2014 Related MedlinePlus Pages African American Health Dialysis Health Disparities MONDAY, June 16, 2014 (HealthDay News) -- ...

273

Depression Doubles Odds of Heart Attack for Younger Women  

Science.gov (United States)

... sharing features on this page, please enable JavaScript. Depression Doubles Odds of Heart Attack for Younger Women: ... 2014) Wednesday, June 18, 2014 Related MedlinePlus Pages Depression Heart Disease in Women WEDNESDAY, June 18, 2014 ( ...

274

Insomnia May Raise Stroke Risk, Especially for Younger Adults  

Science.gov (United States)

... sharing features on this page, please enable JavaScript. Insomnia May Raise Stroke Risk, Especially for Younger Adults ... 2014) Thursday, April 3, 2014 Related MedlinePlus Pages Insomnia Stroke THURSDAY, April 3, 2014 (HealthDay News) -- People ...

275

Gypsum-induced decay in granite monuments in Northwestern Spain  

Digital Repository Infrastructure Vision for European Research (DRIVER)

One of the most common forms of decay in granite monuments is the detachment of the superficial layer of the stone (plaques, plaquettes and scales). Previous studies of granite monuments in the northwest Iberian Peninsula revealed a direct relation between this type of weathering and the presence of calcium sulphate, and a mechanism whereby the salt causes this type of decay was suggested. In the present study, various hypotheses as regards the origin of the gypsum found in granite monuments ...

Silva Hermo, B.; Prieto Lamas, B.; Rivas Brea, T.; Pereira Pardo, L.

2010-01-01

276

A Distributed Network Intrusion Detection System with Active Surveillance Agent  

Directory of Open Access Journals (Sweden)

Full Text Available A distributed network intrusion detection system (IDS called SA-NIDS is proposed based on the network-based intrusion detection architecture. It includes three basic components, Local Intrusion Detection Monitor (LIDM, Global Intrusion Detection Controller (GIDC, and Surveillance Agent (SA. Basically, the LIDM is used to do packets capturing, packets de-multiplexing, local intrusion detection and intrusion inferring. The GIDC is installed in administration center for communicating and managing LIDMs, it can also do the intrusion detection and intrusion inferring. The SA contains several optional functions for information gathering. After an attack behavior is discovered, the SA may be used to launch some kinds of information gathering to the attacker, so that the proposed SA-NIDS has the active surveillance ability. For the intrusion inferring, the pattern matching and the statistical approach are applied in SA-NIDS. The experimental results can satisfy the needs of network information safety.    

Bin Zeng

2013-10-01

277

Diffusion experiment of a radionuclide in granitic rock cores  

International Nuclear Information System (INIS)

An effective diffusion coefficient of neptunium-237 which is one of hazardous long-lived radionuclide including high level radioactive waste was determined by using 40 mm diameter and 5 mm thick disks under an aerobic condition. An alpha autoradiography was performed for cross sections of a 20 mm thick granite disk to study the penetrated neptunium into granite. The effective diffusion coefficient of neptunium diffused through a water saturated granite was about 2.5 x 10"-"1"3 m"2/sec. The autoradiograph of solid state track detectors clearly showed that biotite constituting granite has storage pores and keep diffusing species in it. (author)

1990-01-01

278

Portuguese granites associated with Sn-W and Au mineralizations  

Directory of Open Access Journals (Sweden)

Full Text Available In northern and central Portugal, there are different tin-bearing granites. Most of them are of S-type, others have mixed characteristics of I-type and S-type granites and a few are of I-type. Tin-tungsten deposits are commonly associated with Hercynian tin-bearing S-type granites. Some quartz veins with wolframite are associated with an I-type granite, which has a low Sn content. In suites of tin-bearing S-type granitic rocks, Sn content increases as a function of the degree of fractional crystallization. Greisenizations of two-mica S-type granites associated with tin-tungsten mineralizations are accompanied by an increase in SiO2, H2O+, Sn, W, Nb, Ta, Rb, Zn, and Pb and decrease in MgO, Na2O, V, Sc,Zr, and Sr. The granite associated with the Jales gold deposit is of S-type and strongly differentiated like the tin-bearing S-type granites, but it has a very low Sn content. During fractional crystallization, Si, Rb, Sn, Pb, Au, As, Sb, and S increase. During increasing degree of hydrothermal alteration of this granite at the gold-quartz vein walls, there are progressive increases in K2O, H2O+, Sn, Cs, Cu, Pb, Au, Sb, As, and S.

Ana M.R. Neiva

2002-01-01

279

The link between hydrothermal epigenetic copper mineralization and the Caçapava Granite of the Brasiliano Cycle in southern Brazil  

Science.gov (United States)

Base-metal deposits in the Caçapava do Sul Copper Province are hosted by both volcanosedimentary rocks of the Bom Jardim Group and by metamorphic rocks of the Passo Feio Formation, and show a spatial relationship to the Caçapava Granite. These associations have led to much controversy about the genesis of the base-metal deposits, which has been at least partly resolved by precise dating using SHRIMP (Sensitive High Resolution Ion Microprobe) U/Pb zircon studies combined with S, Pb, and Sr isotope trace studies. The Passo Feio Formation is Neoproterozoic in age and was derived from a complex continental source, as shown by the presence of xenocryst zircons of Archaean, Paleoproterozoic, and Neoproterozoic ages. It was metamorphosed at ca. 700 Ma. The syntectonic Caçapava Granite that intruded the supracrustal rocks of the Passo Feio Formation at 562 Ma was derived from an old sialic basement. Lead-isotope data are consistent with a 562 Ma age for the base-metal sulphide deposits sited in the Passo Feio Formation. The least-radiogenic compositions lie between the field of the isotopic compositions of the Caçapava Granite and rocks of the Passo Feio Formation, suggesting that Pb in the sulphide deposits may have been derived from both sources. The Pb, like that in the Caçapava Granite and Passo Feio Formation, was derived from a primitive crustal source. Sulphur isotope data from the base-metal sulphide deposits in the Passo Feio Formation are compatible with a mixed sedimentary and magmatic source. The most logical model for ore genesis, based on the isotopic data and spatial relationships, is that magmatic metal-bearing fluids from Caçapava Granite leached metals from the Passo Feio Formation and that the deposited sulphides therefore show mixed isotopic signatures. However, there is also some isotopic evidence from the Caçapava Granite itself that suggests assimilation of S-bearing rocks of the Passo Feio Formation during emplacement. Thus, isotopic signatures could have been inherited from assimilated metal sulphides at this stage, and deposition could have been entirely from Caçapava Granite-derived magmatic fluids. Importantly, the inferred 562±8 Ma age for the deposits in the Passo Feio Formation is younger than the well-constrained age of 594±5 Ma for the Camaquã/Santa Maria deposits. Thus, the epigenetic sulphides in the Passo Feio Formation cannot be the source of these deposits as previously suggested. Other isotopic data also argue against such a model.

Remus, M. V. D.; Hartmann, L. A.; McNaughton, N. J.; Groves, D. I.; Fletcher, I. R.

2000-07-01

280

A New Method for Intrusion Detection using Manifold Learning Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Computer and network security has received and will still receive much attention. Any unexpected intrusion will damage the network. It is therefore imperative to detect the network intrusion to ensure the normal operation of the internet. There are many studies in the intrusion detection and intrusion patter recognition. The artificial neural network (ANN has proven to be powerful for the intrusion detection. However, very little work has discussed the optimization of the input intrusion features for the ANN. Generally, the intrusion features contain a certain number of useless features, which is useless for the intrusion detection. Large dimensions of the feature data will also affect the intrusion detection performance of the ANN. In order to improve the ANN performance, a new approach for network intrusion detection based on nonlinear feature dimension reduction and ANN is proposed in this work. The manifold learning algorithm was used to reduce the intrusion feature vector. Then an ANN classifier was employed to identify the intrusion. The efficiency of the proposed method was evaluated with the real intrusion data. The test result shows that the proposed approach has good intrusion detection performance.

Guoping Hou

2013-07-01

 
 
 
 
281

NETWORK INTRUSION DETECTION SYSTEM USING FUZZY LOGIC  

Directory of Open Access Journals (Sweden)

Full Text Available IDS which are increasingly a key part of system defense are used to identify abnormal activities in a computer system. In general, the traditional intrusion detection relies on the extensive knowledge of security experts, in particular, on their familiarity with the computer system to be protected. To reduce this dependence, variousdata-mining and machine learning techniques have been used in the literature. In the proposed system, we have designed fuzzy logic-based system for effectively identifying the intrusion activities within a network. The proposed fuzzy logic-based system can be able to detect an intrusion behavior of the networks since the rule base contains a better set of rules. Here, we have used automated strategy for generation of fuzzy rules, which are obtained from the definite rules using frequent items. The experiments and evaluations of the proposed intrusion detection system are performed with the KDD Cup 99 intrusion detection dataset. The experimentalresults clearly show that the proposed system achieved higher precision in identifying whether the records are normal or attack one.

R. Shanmugavadivu

2011-02-01

282

Tourmaline occurrences within the Penamacor-Monsanto granitic pluton and host-rocks (Central Portugal): genetic implications of crystal-chemical and isotopic features  

Science.gov (United States)

Tourmalinization associated with peraluminous granitic intrusions in metapelitic host-rocks has been widely recorded in the Iberian Peninsula, given the importance of tourmaline as a tracer of granite magma evolution and potential indicator of Sn-W mineralizations. In the Penamacor-Monsanto granite pluton (Central Eastern Portugal, Central Iberian Zone), tourmaline occurs: (1) as accessory phase in two-mica granitic rocks, muscovite-granites and aplites, (2) in quartz (±mica)-tourmaline rocks (tourmalinites) in several exocontact locations, and (3) as a rare detrital phase in contact zone hornfels and metapelitic host-rocks. Electron microprobe and stable isotope (?18O, ?D, ?11B) data provide clear distinctions between tourmaline populations from these different settings: (a) schorl-oxyschorl tourmalines from granitic rocks have variable foititic component (X? = 17-57 %) and Mg/(Mg + Fe) ratios (0.19-0.50 in two-mica granitic rocks, and 0.05-0.19 in the more differentiated muscovite-granite and aplites); granitic tourmalines have constant ?18O values (12.1 ± 0.1 ‰), with wider-ranging ?D (-78.2 ± 4.7 ‰) and ?11B (-10.7 to -9.0 ‰) values; (b) vein/breccia oxyschorl [Mg/(Mg + Fe) = 0.31-0.44] results from late, B- and Fe-enriched magma-derived fluids and is characterized by ?18O = 12.4 ‰, ?D = -29.5 ‰, and ?11B = -9.3 ‰, while replacement tourmalines have more dravitic compositions [Mg/(Mg + Fe) = 0.26-0.64], close to that of detrital tourmaline in the surrounding metapelitic rocks, and yield relatively constant ?18O values (13.1-13.3 ‰), though wider-ranging ?D (-58.5 to -36.5 ‰) and ?11B (-10.2 to -8.8 ‰) values; and (c) detrital tourmaline in contact rocks and regional host metasediments is mainly dravite [Mg/(Mg + Fe) = 0.35-0.78] and oxydravite [Mg/(Mg + Fe) = 0.51-0.58], respectively. Boron contents of the granitic rocks are low (tourmaline saturation in granitic melts, implying loss of B and other volatiles to the surrounding host-rocks during the late-magmatic stages. This process was responsible for tourmalinization at the exocontact of the Penamacor-Monsanto pluton, either as direct tourmaline precipitation in cavities and fractures crossing the pluton margin (vein/breccia tourmalinites), or as replacement of mafic minerals (chlorite or biotite) in the host-rocks (replacement tourmalinites) along the exocontact of the granite. Thermometry based on 18O equilibrium fractionation between tourmaline and fluid indicates that a late, B-enriched magmatic aqueous fluid (av. ?18O ~12.1 ‰, at ~600 °C) precipitated the vein/breccia tourmaline (?18O ~12.4 ‰) at ~500-550 °C, and later interacted with the cooler surrounding host-rocks to produce tourmaline at lower temperatures (400-450 °C), and an average ?18O ~13.2 ‰, closer to the values for the host-rock. Although B-metasomatism associated with some granitic plutons in the Iberian Peninsula seems to be relatively confined in space, extending integrated studies such as this to a larger number of granitic plutons may afford us a better understanding of Variscan magmatism and related mineralizations.

da Costa, I. Ribeiro; Mourão, C.; Récio, C.; Guimarães, F.; Antunes, I. M.; Ramos, J. Farinha; Barriga, F. J. A. S.; Palmer, M. R.; Milton, J. A.

2014-04-01

283

A-type and I-type granitoids and mylonitic granites of Hassan Salaran area of SE Saqqez, Kurdistan, Iran  

Science.gov (United States)

The Hassan Salarn area is located 20km to southeast of Saqqez city in Kurdistan Province, western Iran. In this area there are two distinct granitic rock suites consisting A-type and I-type granites and also mylonitic granites. These A-type and I-type granites have various petrological and geochemical characteristics. They also have different origins and petrogenesis. A-type granitoids comprise alkali feldspar granite, syenogranite and quartz alkali feldspar syenite, whereas I-type granitoids are composed of monzogranite, granodiorite and tonalite. Geochemically, A-type granitoids are peralkaline and acmite-normative but I-type granitoids are subalkaline (calc-alkaline), metaluminous and diopside-normative. A-type granitoids are also ferroan alkali and ferroan alkali-calcic whereas I-type granitoids are magnesian and calcic. A-type granitoids resemble to within plate granites and post-orogenic granites whereas I-type granitoids resemble to volcanic arc granites. A-type granitoids contain higher concentrations of alkalies, Zr, Rb, Nb, Y, Th, Ce, high FeO/MgO ratios and lower concentrations of Mg, Ca and Sr, resembling post-orogenic A-type granites. It is possible that heat from a mantle-derived magma which intruded into the lower crust, and/or rapid crustal extension have been essential generation of approriate melts producing A-type granitoids. Thus we can conclude that A-type granitoids were generated from a mixed mantle-crust source. Negative Nb anomalies and low contents of Ti and P probably indicate a subduction-related origin for protolith of I-type granitoids. Negative Nb anomalies and enrichment in Ce relative to its adjacent elements can be related to involvement of continental crust in magmatic processes. I-type granitoids are also enriched in Rb, Ba, K, Th, Ce and depleted in Nb, Zr and Y, indicating that they have had interacted with crust. I-type granitoids may result from contamination of mantle-derived magmas by continental crust during a subduction event. The mylonitic granites are elongated masses with a NE-SW trend and their contacts with the A-type and I-type granitoids are fault contact. Hand specimens have a layered appearance with green bands made from chlorite and epidote and grey to white bands with quartz and feldspar. These rocks contain plagioclase, quartz and orthoclase under the microscope. Also fine-grained minerals such as quartz, sericite, epidote, chlorite and opaque minerals make the groundmass wrapping the porphyroclasts. Pressure shadows around porphyroclasts of plagioclase and quartz and crystallization of fine-grained quartz and sericite in these places along with intense alteration of plagioclase to epidote and sericite, existence of quartz with different sizes, andaluse extinction in quartz crystals, and elongation of chlorites, resulted from dynamic recrystallisation of biotites all indicate effect of stresses on the rocks. Considering the similar mineralogical composition of the mylonitic rocks with I-type granitoid, it could be concluded that the granodioritic magma, after intrusion and solidification, is changed to mylonite in a shear zone due to tectonical forces.

Abdullah, Fakhraddin Mohammad; Saeed Ahmad, Sheler

2014-05-01

284

Geochronology, petrogenesis and tectonic significance of the Jitang granitic pluton in eastern Tibet, SW China  

Science.gov (United States)

The Jitang granitic pluton, which is situated in the southern margin of the North Qiangtang block in eastern Tibet, may provide critical information about the source and derivation of the North Qiangtang block during Gondwana breakup and dispersion. In this paper we report relevant data such as zircon U-Pb age, whole-rock major and trace element abundances, and Sr-Nd isotopes for the Jitang pluton. The major rock types of the pluton are granodiorite and biotite granite. Whole-rock major element data reveal that the Jitang pluton is a peraluminous S-type granitic pluton. The U-Pb age of zircons from the pluton is 219.1 ± 1.7 Ma, which is ~ 10 Ma younger than the age of high-pressure metamorphism in the Longmu Co-Shuanghu collisional suture between the North and South Qiangtang blocks. The Jitang granitoids show pronounced negative Ba-Eu-Sr anomalies, high initial 87Sr/86Sr ratios from 0.7266 to 0.7389 and low ?Nd(t) values for from - 11.1 to - 13.2, which are remarkably similar to the gneisses and meta-sedimentary rocks from the Indian craton as well as the North Qiangtang block. The results from this study indicate that the Jitang granitoids formed by melts derived from a crustal source with Sr-Nd isotopic compositions similar to those of the Indian cratonic crust. We concur with the previous interpretation based on detrital zircon records that the North Qiangtang block was derived from the Indian Gondwana.

Tao, Yan; Bi, Xianwu; Li, Chusi; Hu, Ruizhong; Li, Yubang; Liao, Mingyang

2014-01-01

285

Sm/Nd and whole rock geochemistry characterization of the Serra Branca granite: evidence of Archean crust in the Pajeu Paraiba fold belt  

International Nuclear Information System (INIS)

This work presents and discusses the geochemical and Samarium-Neodymium (SM/Nd) isotopic data for the Serra Branca granite. The Serra Branca granite constitutes one among several brasiliano (=Pan African) intrusions of the transversal zone of the Borborema Tectonica Province, northeastern of Brazil. It is intruded into gneisses and migmatites from the Alto Pajeu Terrain (TAP). The Alto Pajeu Terrain comprises mainly metasediments with minor volcanic contributions and the brasiliano magmatism is restrict to the TAP. After presenting the geological and petrographical considerations, the study shows the Sm-Nd data and concludes that the geochemical and Sm-Nd isotopic signatures of the Serra Branca complex point to a magma generation in the contact zone between an Archean and a Tranzamazonian crust, during decompression, which followed the Brasiliano collisional event

1997-11-16

286

Pan-African alkali granites and syenites of Kerala as imprints of taphrogenic magmatism in the South Indian shield  

Science.gov (United States)

Granite and syenite plutons with alkaline affinities ranging in age from 550 to 750 Ma sporadically puncture the Precambrian granulites of the Kerala region. All the bodies are small (20 to 60 sq km), E-W to NW-SE elongated elliptical intrusives with sharp contacts and lie on or close to major late Proterozoic lineaments. Geochemical plots of A-F-M and An-Ab-Or relations show an apparent alkali enrichment trend on the former, but the plutons define relatively distinct fields on the latter. Most of the plutons are adamellitic to granitic by chemistry. The variations of SiO2 with log sub 10 K2O/MgO (1) brings out the distinct alkaline nature of the plutons. Some of the granites are extremely potassic, like the Peralimala pluton, which shows up to 11.8 percent K2O. On a SiO2-Al2O3-Na2O+K2O (mol percent) plot, the plutons vary from peraluminous to peralkaline, but none are nepheline normative. Low MgO, low to moderate CaO and high Fe2O3/FeO values are other common characteristics. Among trace elements, depletion of Ba, Sr and Rb with high K/Ba and K/Rb values are typical. Overall, the plutons show a trend of decreasing K/Rb ratio with increasing K content. Individual plutons show more clearly defined trends similar to those from granitic masses characterized by plagioclase fractionation.

Santosh, M.; Drury, S. A.; Iyer, S. S.

1988-01-01

287

Petrogenesis of the mineralized granitic intrusion near Los Santos, Western Spain, and remote sensing and data integration as a tool in regional exploration for granite related mineralization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ground based metal exploration is labour intensive and thus expensive. Data acquisition by satellite and aircraft, and subsequent image processing seem to offer a cheaper and attractive strategy to replace some of this effort, notably in the screening phase of a new project. However, realizing this promise requires considerably more than an image processing system and some satellite data. A vital component is a calibration area with known mineralization where the geology is suffic...

Goossens, M. A.

1992-01-01

288

Effective analysis of cloud based intrusion detection system  

Directory of Open Access Journals (Sweden)

Full Text Available The goal of IDS is to analyze events on the network and identify attacks. The increasing number of network security related incidents makes it necessary for organizations to actively protect their sensitive data with the installation of intrusion detection systems (IDS. People are paid more attention on intrusion detection which as an important computer network security technology. According to the development trend of intrusion detection, detecting all kinds of intrusions effectively requires a global view of the monitored network, Here, discuss about new intrusion detection mechanism based on cloud computing, which can make up for the deficiency of traditional intrusion detection, and proved to be great scalable.

Sanjay Ram

2012-08-01

289

An overview to Software Architecture in Intrusion Detection System  

CERN Multimedia

Network intrusion detection systems provide proactive defense against security threats by detecting and blocking attack-related traffic. This task can be highly complex, and therefore, software based network intrusion detection systems have difficulty in handling high speed links. This paper reviews of many type of software architecture in intrusion detection systems and describes the design and implementation of a high-performance network intrusion detection system that combines the use of software-based network intrusion detection sensors and a network processor board. The network processor acts as a customized load balancing splitter that cooperates with a set of modified content-based network intrusion detection sensors in processing network traffic.

Bahrami, Mehdi

2012-01-01

290

Monoclinal bending of strata over laccolithic intrusions  

Science.gov (United States)

Sedimentary strata on top of some laccolithic intrusions are nearly horizontal and little deformed, but are bent into steeply dipping monoclinal flexures over the peripheries of these intrusions. This form of bending is not explained by previous theories of laccolithic intrusion, which predict either horizontal undeformed strata over the center and faulted strata around the periphery, or strata bent continuously into a dome. However, a slight generalization of these theories accomodates the observed form and contains the previous forms as special cases. A critical assumption is that the strength of contacts within a multilayered overburden is overcome locally by layer-parallel shear. If this strength is less than the strength of the layers themselves, then layers over the center remain bonded together and display negligible bending, whereas layers over the periphery slip over one another and are readily bent into a monoclinal flexure. ?? 1981.

Koch, F. G.; Johnson, A. M.; Pollard, D. D.

1981-01-01

291

Multidimensional Network Monitoring for Intrusion Detection  

CERN Multimedia

An approach for real-time network monitoring in terms of numerical time-dependant functions of protocol parameters is suggested. Applying complex systems theory for information f{l}ow analysis of networks, the information traffic is described as a trajectory in multi-dimensional parameter-time space with about 10-12 dimensions. The network traffic description is synthesized by applying methods of theoretical physics and complex systems theory, to provide a robust approach for network monitoring that detects known intrusions, and supports developing real systems for detection of unknown intrusions. The methods of data analysis and pattern recognition presented are the basis of a technology study for an automatic intrusion detection system that detects the attack in the reconnaissance stage.

Gudkov, V; Gudkov, Vladimir; Johnson, Joseph E.

2002-01-01

292

Developing Mobile Agent for Intrusion Detection  

Directory of Open Access Journals (Sweden)

Full Text Available Mobile agent is a certain agent actively able to move from one computer to another or even travel acrossnetwork to perform the task assigned. This research aimed to develop mobile agent model to detectdistributed intrusion (Distributed Intrusion Detection System.It was expected that the produced model was able to perform its task in nearly real time manner, to beimmune against attack, and also fairly small overhead at the host, either in memory consumption or CPUusage. In this research, the Aglets concept was also developed to aid intrusion detection. This approachwas also maintained to solve certain issues such as scalability, reliability, and configurability. Hence, theadvantages and limitations of agent-based approaches will be when it is applied in real world.

Bambang Sugiantoro

2013-05-01

293

Resaturation of backfilled tunnels in granite  

International Nuclear Information System (INIS)

Highly compacted bentonite clay is proposed for use as a backfill material around high level waste overpacks to be placed in excavated tunnels in the crystalline bedrock of Northern Switzerland. Initially the bentonite will have a low residual water content and with time the bentonite will resaturate due to the influx of water from the crystalline rock. The time and degree of bentonite saturation are important for safety assessment because of their effect on the corrosion of the waste overpack, on the leaching of the waste matrix, and on the radionuclide transport in the backfill. A three-dimensional, two-phase flow model (FAMOS) is used to quantify the expected resaturation under the conditions outlined above. The time required for complete saturation simulated using FAMOS ranges from less than 100 to more than 1000 years. These results are comparable to the results of diffusive models of bentonite saturation when using a diffusion coefficient of 3x10"-"1"0 m"2s"-"1. The time depends on the hydraulic properties of the bentonite as well as the saturated hydraulic conductivity of the crystalline rock. At saturated granite hydraulic conductivities of the order of 10"-"9 ms"-"1 the bentonite becomes fully saturated in less than 100 years. For saturated granite hydraulic conductivities of the order of 10"-"1"2 ms"-"1 the bentonite becomes fully saturated in several hundred to over 1000 years. For a given granite hydraulic conductivity the degree of saturation depends on the bentonite capillary pressure versus water saturation characteristic relationships. For high capillary pressures (of the order of 10"5 kPa) the bentonite saturates relatively quickly; with lower capillary pressures the time for complete saturation increases

1986-01-01

294

Characterization of Climax granite ground water  

International Nuclear Information System (INIS)

The Climax ground water fails to match the commonly held views regarding the nature of deep granitic ground waters. It is neither dilute nor in equilibrium with the granite. Ground-water samples were taken for chemical analysis from five sites in the fractured Climax granite at the Nevada Test Site. The waters are high in total dissolved solids (1200 to 2160 mg/L) and rich in sodium (56 to 250 mg/L), calcium (114 to 283 mg/L) and sulfate (325 to 1060 mg/L). Two of the samples contained relatively high amounts of uranium (1.8 and 18.5 mg/L), whereas the other three contained uranium below the level of detection (< 0.1 mg/L). The pH is in the neutral range (7.3 to 8.2). The differences in composition between samples (as seen in the wide range of values for the major constituents and total dissolved solids) suggest the samples came from different, independent fracture systems. However, the apparent trend of increasing sodium with depth at the expense of calcium and magnesium suggests a common evolutionary chemical process, if not an interconnected system. The waters appear to be less oxidizing with depth (+ 410 mV at 420 m below the surface vs + 86 mV at 565 m). However, with Eh measurements on only two samples, this correlation is questionable. Isotopic analyses show that the waters are of meteoric origin and that the source of the sulfate is probably the pyrite in the fracture-fill material. Analysis of the measured water characteristics using the chemical equilibrium computer program EQ3 indicates that the waters are not in equilibrium with the local mineral assemblage. The solutions appear to be supersaturated with respect to the mineral calcite, quartz, kaolinite, muscovite, k-feldspar, and many others

1982-01-01

295

Simulation of bentonite colloid migration through granite  

International Nuclear Information System (INIS)

Document available in extended abstract form only. Full text of publication follows: Colloidal bentonite particles generate at the interface of buffer and host rock in spent nuclear fuel repository due to an erosion process and migrate through granite by the water flow. Stability of these colloids and their migration possibilities have been studied on account of radionuclide transport possibility as colloid could carry adsorbed radionuclides in groundwater through granite. That is why a simulation of bentonite colloid migration in the surrounding of a repository might be requested. According to chemical condition as ionic strength and pH, the colloidal particles coagulate into clusters and that influence the migration of particles. The coagulation kinetics of natural bentonite colloids were experimentally studied in many articles, for example by light scattering techniques. We created a model of coagulation of bentonite colloids and simulation of a chosen experiment with use of the multicomponent reactive transport equation. The coagulation model describes clustering of particles due to attractive van der Waals forces as result of collision of particles due to heat fluctuation and different velocity of particles during sedimentation and velocity gradient of water flow. Next, the model includes influence of repulsive electrostatic forces among colloidal particles leading to stability of particles provided high surface charge of colloids. In the model, each group of clusters is transported as one solution component and the kinetics of coagulation are implemented as reactions between the components: a shift of particles among groups of particles with similar migration properties, according to size of the clusters of colloids. The simulation of migration of bentonite colloid through granite using the coagulation model was calibrated according to experiment results. On the basis of the simulation, one can estimate the basic processes that occur during bentonite colloid migration. That could be useful for prediction of spent nuclear fuel repository safety with the help of model of bentonite colloid behavior during migration. (authors)

2012-10-01

296

GRANITE CHIEF WILDERNESS STUDY AREA, CALIFORNIA.  

Science.gov (United States)

The Granite Chief Wilderness study area encompasses 57 sq mi near the crest of the Sierra Nevada 6 mi west of Tahoe City, California. Geologic, geochemical, and mines and prospect studies were carried out to assess the mineral-resource potential of the area. On the basis of the mineral-resource survey, it is concluded that the area has little promise for the occurrence of precious or base metals, oil, gas, coal, or geothermal resources. Sand, gravel, and glacial till suitable for construction materials occur in the area, but inaccessability and remoteness from available markets preclude their being shown on the map as a potential resource.

Harwood, David, S.; Federspiel, Francis, E.

1984-01-01

297

Thermoluminescence of the mineral components in granite  

International Nuclear Information System (INIS)

The thermoluminescence (TL) of the minerals in Climax Stock (Nevada, USA) granite has been studied. The principal mineral constituents are plagioclase, quartz, potassium feldspar and biotite. Pyrite, sphene apatite and zircon occur at one percent or less. All exhibit TL except biotite. The TL kinetics were determined for plagioclase, quartz, potassium feldspar and pyrite. Plagioclase and potassium feldspar exhibit second order and pyrite first orker kinetics. Natural TL of quartz follows second order and artificial TL first order kinetics. However, in these four minerals unrealistic kinetic parameters are often obtained; thus more general kinetics, e.g. interactive kinetics, may apply. 8 figures

1982-07-01

298

GRANITE- A steroscopic imaging Chernkov telescope system  

International Nuclear Information System (INIS)

A second 10 meter class imaging telescope was constructed on Mt. Hopkins, Arizona, the site of the original 10 meter Whipple Cherenkov telescope. The twin telescope system with a 140 meter base line will allow both a reduction in the energy threshold and an improvement in the rejection of the hardonic background. The new telescope started operation in December 1991. With the final completion of the first installation stage (GRANITE I) during spring 92, it is now operating simultaneously with the orginal reflector. We describe in this paper design and construction of the new instrument and demonstrate the capability of the experiment to record coincident events

1993-07-05

299

Characterization of mechanical damage in granite  

Directory of Open Access Journals (Sweden)

Full Text Available This paper aims to illustrate the use of infrared thermography as a non-destructive and non-contact technique to observe the phenomenological manifestation of damage in granite under unconfined compression. It allows records and observations in real time of heat patterns produced by the dissipation of energy generated by plasticity. The experimental results show that this technique, which couples mechanical and thermal energy, can be used for illustrating the onset of damage mechanism by stress concentration in weakness zones.

Minh-Phong Luong

2014-01-01

300

IRETHERM: The geothermal energy potential of Irish radiothermal granites  

Science.gov (United States)

The IRETHERM project is developing a strategic understanding of Ireland's deep geothermal energy potential through integrated modelling of new and existing geophysical and geological data. One aspect of IRETHERM's research focuses on Ireland's radiothermal granites, where increased concentrations of radioelements provide elevated heat-production (HP), surface heat-flow (SHF) and subsurface temperatures. An understanding of the contribution of granites to the thermal field of Ireland is important to assessing the geothermal energy potential of this low-enthalpy setting. This study focuses on the Galway granite in western Ireland, and the Leinster and the buried Kentstown granites in eastern Ireland. Shallow (production is measured at 2.4 ?Wm-3 in core samples taken from the weathered top 30 m of the granite. The core of this study consists of a program of magnetotelluric (MT) and audio-magnetotelluric (AMT) data acquisition across the three granite bodies, over three fieldwork seasons. MT and AMT data were collected at 59 locations along two profiles over the Leinster granite. Preliminary results show that the northern units of the Leinster granite (40 km SW of Dublin) extend to depths of 2-5 km. Preliminary results from the southern profile suggest a greater thickness of granite to a depth of 6-9 km beneath the Tullow pluton, 75 km SW of Dublin. Over the Galway granite, MT and AMT data have been collected at a total of 75 sites (33 consist of only AMT data acquisition, with both MT and AMT recorded at the remaining 42). Preliminary results show a deep resistor extending to depths of 15-20 km beneath the central block, with the resistive upper layer extending to depths of 3.5-7 km west of the Shannawona fault, a major structure that cuts the batholith. MT and AMT data acquired along a profile at 22 locations over the Kentstown granite suggests that this buried granite is at a depth of 400 m beneath the centre of the gravity anomaly. The MT and AMT data will be integrated with gravity and seismic refraction data (in the case of the Leinster granite) to identify deeply penetrating faults, which may provide conduits for hydrothermal fluids, and to produce a robust estimation of the volumetric extent of the granites, which is crucial in defining their geothermal energy potential. Thermal conductivity and geochemical data will be incorporated to constrain the heat contribution of granites to the Irish crust.

Farrell, Thomas; Jones, Alan; Muller, Mark; Feely, Martin; Brock, Andrew; Long, Mike; Waters, Tim

2014-05-01

 
 
 
 
301

Adaptive intrusion data system (AIDS) software routines  

International Nuclear Information System (INIS)

An Adaptive Intrusion Data System (AIDS) was developed to collect information from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data-compression, storage, and formatting system; it also incorporates a capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be used for the collection of environmental, bilevel, analog, and video data. This report describes the software routines that control the different AIDS data-collection modes, the diagnostic programs to test the operating hardware, and the data format. Sample data printouts are also included

1980-01-01

302

ANOMALY INTRUSION DETECTION SYSTEM USING NEURAL NETWORK?  

Directory of Open Access Journals (Sweden)

Full Text Available As human body remain secure from various environmental anomalies so as our computers alsohave security from the network intrusions. This paper proposes a new technique to intrusion detection systemthat can be effectively find and classify different afflictions. This system has to identify dynamic behaviour ofsystems. There are several techniques to help IDS to identify and get the changing behaviour of system. Inthis paper we are going to use artificial neural network ANN to get system changes. To get desired result wecan use KDD'99 data set in our IDS system.

Ms. Vrushali D Mane

2013-08-01

303

Adaptive intrusion data system (AIDS) software routines  

Energy Technology Data Exchange (ETDEWEB)

An Adaptive Intrusion Data System (AIDS) was developed to collect information from intrusion alarm sensors as part of an evaluation system to improve sensor performance. AIDS is a unique digital data-compression, storage, and formatting system; it also incorporates a capability for video selection and recording for assessment of the sensors monitored by the system. The system is software reprogrammable to numerous configurations that may be used for the collection of environmental, bilevel, analog, and video data. This report describes the software routines that control the different AIDS data-collection modes, the diagnostic programs to test the operating hardware, and the data format. Sample data printouts are also included.

Corlis, N.E.

1980-07-01

304

Intrusion Detection Using Cost-Sensitive Classification  

CERN Multimedia

Intrusion Detection is an invaluable part of computer networks defense. An important consideration is the fact that raising false alarms carries a significantly lower cost than not detecting at- tacks. For this reason, we examine how cost-sensitive classification methods can be used in Intrusion Detection systems. The performance of the approach is evaluated under different experimental conditions, cost matrices and different classification models, in terms of expected cost, as well as detection and false alarm rates. We find that even under unfavourable conditions, cost-sensitive classification can improve performance significantly, if only slightly.

Mitrokotsa, Aikaterini; Douligeris, Christos

2008-01-01

305

Hydrothermal alteration of granite by meteoric fluid: an example from the Carnmenellis Granite, United Kingdom  

Science.gov (United States)

The interaction of granitic rock with meteoric fluid is instrumental in determining the chemistry of pore fluids and alteration mineralogy in downflow portions of convective groundwater circulation cells associated with many hydrothermal systems in the continental crust. Hydrothermal experiments and a detailed mineralogical study have been carried out to investigate the hydrothermal alteration of the Carnmenellis Granite, Cornwall, UK. Samples of drill chippings from a borehole 2 km deep in the Carnmenellis Granite have been reacted with a dilute Na-HCO3-Cl fluid in hydrothermal solution equipment at temperatures of 80°, 150° and 250° C and a pressure of 50 MPa, with a water/rock mass ratio of 10, for experiment durations up to 200 days. Fluid samples were analysed for seventeen different chemical components, and solids were examined prior to, and after reaction using SEM, electron microprobe and conventional light optic techniques. Experimental fluids were mildly alkaline (pH 7 8.5) and of low salinity (TDS laumontite (at 150° C), wairakite and anhydrite (at 250° C). Final fluids were saturated with respect to quartz and fluorite. Certain trace elements (Li, B, Sr) were either incorporated into solids precipitated during the experiments or sorbed onto mineral surfaces and cannot be considered as ‘conservative’ (partitioned into the fluid phase) elements. Concentrations of all analysed chemical components showed net increases during the experiments except for Ca (at 250° C) and Mg (at all temperatures). A comparison of the alteration mineralogy observed in the experiments with that present as natural fracture infills in drillcore from the Carnmenellis Granite reveals that the solid products from the experiments correspond closely to mineral assemblages identified as occurring during the later stages of hydrothermal circulation associated with the emplacement of the granite.

Savage, David; Cave, Mark R.; Milodowski, Antoni E.; George, Ian

1987-07-01

306

The intrusive complexof the Island of Giglio: geomagnetic characteristics of plutonic facies with low susceptibility contrast  

Directory of Open Access Journals (Sweden)

Full Text Available Two main plutonic facies characterize the intrusive complex of the Island of Giglio, and the trend of their contact at depth has been modelled using a 2D½ analysis based on a detailed geomagnetic survey in order to verify the geological hypothesis of the subsurface geometry of this contact. The magnetic anomaly connected with the discontinuity is quite low, due to the small difference between the magnetic susceptibilities of the two granitic facies. Development of this model of inversion of the magnetic field, which is in good agreement with the geological interpretation, was made possible by: 1 accurate control of the geomagnetic time variations and consequent temporal reduction, 2 a very low level of the artificial magnetic noise, 3 high density of the magnetic survey, 4 detailed knowledge of the mapped geologic contact between facies and of their petrologic characteristics, and 5 direct local measurements of the magnetic susceptibilities of the key lithologies. The model shows the trends of the geological contact, as projected in three E-W sections, that dips eastward in the range between 210 and 540, supporting the geologic hypothesis that the Pietrabona facies represents an external shell of the shallowly emplaced Giglio monzogranite intrusion.

R. Cavallini

1998-06-01

307

Natural radioactivity of granite rocks in Wadi Qena  

Science.gov (United States)

Compressed powdered granite samples brought from G. El Missikat and G. El Garra with different ages were analyzed by low-level ? spectrometry. The contents of U, Th and K were determined and the dependence on age was tested. U/Th and U/K ratios for young and old granite samples were evaluated. Results were discussed and compared with other experiments.

Saied, M. H.; Abbady, A.; El-Kamel, A. H.; El-Arabi, A.

1994-07-01

308

Visualization of water permeation into granite by neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Neutron radiography experiments were performed to visualize water permeation into granite. Four types of cubic granite samples, 40 mm in length, were placed on a wet sponge, and neutron radiographs were taken every {approx}10 min. The developments of water permeation front could be observed by subtracting the brightness of the two consecutive images.

Cho, A. [Institute for Geo-Resources and Environment, AIST, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8567 (Japan)], E-mail: akio.cho@aist.go.jp; Matsubayashi, M. [Quantum Beam Science Directorate, JAEA, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Hasegawa, S. [Haguro Stone Producers' Cooperative Association, 958, Tomobe, Sakuragawa, Ibaraki 309-1453 (Japan)

2009-06-21

309

Geology and Petrogenesis of the Southern Closepet Granite.  

Science.gov (United States)

The Archaean Closepet Granite is a polyphase body intruding the Peninsular Gneiss Complex and the associated supracrustal rocks. The granite out-crop runs for nearly 500 km with an approximate width of 20 to 25 km and cut across the regional metamorphic s...

M. Jayananda B. Mahabaleswar K. A. Oak C. R. L. Friend

1988-01-01

310

Large Meteorite Impacts and Genesis of Precambrian Granites  

Science.gov (United States)

The earth scientists have been in pursuit for long to resolve granite genesis enigma. The Precambrian Dhala granites and Malani Rhyolites of India have their origin due to impact. It is thus proposed to find relation of impact and silicic provinces.

Sisodia, M. S.

2013-08-01

311

The 'Granite' collegial mission of dialogue. Report  

International Nuclear Information System (INIS)

The aim of the 'Granite' collegial mission of dialogue is to inform the French authorities, associations and population about the project of construction of an underground laboratory for the study of the disposal of high level and long-life radioactive wastes in a granitic environment. The aim of the dialogue was not to select a site but to collect the public reactions and advices about such a project. However, such a dialogue has partially failed because of a misunderstanding of the population about the aims of the mission. However, the mission has collected many point of views and questions which are developed in this report. The first and second chapters recall the process of the mission and its progress, while a third chapter stresses on the questions asked by the public and which concern the fear of nuclear wastes and the incompatibility between the disposal of wastes and the socio-economical development of the region concerned. Thanks to the lessons drawn from this experience, the mission has formulated some recommendations (chapter 4) concerning the need for a better information of the population about any topic in relation with the radioactive wastes. Some complementary information is provided in appendixes. (J.S.)

2000-01-01

312

In-situ experiments in granite  

International Nuclear Information System (INIS)

In-stitu experiments in granite were started in 1983 as a three-year plan of research and development of the experimental techniques to aime at development of a site assessment methodology and to provide the data for the safety assessment of the disposal of radioactive waste. At the test site of granite, an experimental room was excavated for exclusive use and heater test, migration test and corrosion test were performed. The heater test showed good agreement between measured and calculated temperatures in the rock where no fracture was found, however, in fractured zone it showed that the heat transfer by the ground water could not be disregarded. Rock deformation and permiability change were found near the heater in the fractured zone. Nuclide transport along the fracture is much faster than the transport in the rock matrix, besides dispersion in the rock matrix has very important role from the migration test. Corrosion test used sensitized specimens showed that some samples have susceptibilities to stress corrosion cracking after 12 months. (author)

1986-01-01

313

Warren Hunt to test granite well  

Energy Technology Data Exchange (ETDEWEB)

Various theories which purport to explain the existence of the Alberta oil sands, were discussed briefly. One theory, held among others by Warren Hunt, speculates that oil is formed deep in the Precambrian basement and not in the higher sedimentary rock. According to this theory, methane in the crust is the abiogenic product that results from hydrogen reacting with silicon carbide in the lower mantle. As it rises through the fractures, it encounters the microbiota, and hydrogen is stripped away making larger molecules until only bitumen remains. Hunt and other adherents of this theory believe that hydrocarbon reservoirs are replenished as oil is produced, hence there is no end to the world`s oil supply. This theory is about to be tested by retesting a granite well near Fort McMurray, which was suspended in September 1994, when funding dried up. Kaleeda Enterprises, owners of the well, believe that the well bottom is currently in a granite pool, and oil will be found by deepening the well to 2,150 metres from the current 1,650 metres. While this is not universally accepted, if true, the abiogenic theory would go a long way towards explaining the origin of the oil sands.

Harvie, W.

1996-07-08

314

Warren Hunt to test granite well  

International Nuclear Information System (INIS)

Various theories which purport to explain the existence of the Alberta oil sands, were discussed briefly. One theory, held among others by Warren Hunt, speculates that oil is formed deep in the Precambrian basement and not in the higher sedimentary rock. According to this theory, methane in the crust is the abiogenic product that results from hydrogen reacting with silicon carbide in the lower mantle. As it rises through the fractures, it encounters the microbiota, and hydrogen is stripped away making larger molecules until only bitumen remains. Hunt and other adherents of this theory believe that hydrocarbon reservoirs are replenished as oil is produced, hence there is no end to the world's oil supply. This theory is about to be tested by retesting a granite well near Fort McMurray, which was suspended in September 1994, when funding dried up. Kaleeda Enterprises, owners of the well, believe that the well bottom is currently in a granite pool, and oil will be found by deepening the well to 2,150 metres from the current 1,650 metres. While this is not universally accepted, if true, the abiogenic theory would go a long way towards explaining the origin of the oil sands

1996-07-08

315

Uranium in the Carnmenellis granite, Cornwall, England  

International Nuclear Information System (INIS)

Samples from a 30 meter core from the Rosemanowas quarry in the Carnmenellis granite in Cornwall, England were analyzed by induced fission track detection, delayed neutron detection, backscattered electron imaging in a SEM, and energy dispersive x-ray spectrometry. Uranium occurs mainly in: (1) primary accessory minerals; (2) alteration and replacement phases, and (3) microcrack-sealing phases. Zircon, monazite, and apatite are common uraniferous primary accessory minerals. Uraniferous alteration phases include hematite, rutile and pyrolusite. Hematite is a common uraniferous replacement phase. Most sealed microcracks contain uranium. Hematite and pyrolusite are ubiquitous uraniferous crack-sealing phases. Autunite and churchite are occasional uraniferous crack-sealing phases. Whole rock uranium concentrations are extremely variable. High uranium contents result from high percentages of uraniferous primary accessory phases and/or rutile. Hydrothermal activity, such as hematization, can result in depleted whole rock uranium concentrations. Results of this study indicate that uranium and light rare earth elements have been mobilized and redistributed in this section of the Carnmenellis granite by postmagmatic processes. 28 refs., 13 figs. 2 tabs

1984-01-01

316

BTSC VAPOR INSTRUSION PRIMER "VAPOR INTRUSION CONSIDERATION FOR REDEVELOPMENT"  

Science.gov (United States)

This primer is designed for brownfields stakeholders concerned about vapor intrusion, including property owners, real estate developers, and contractors performing environmental site investigations. It provides an overview of the vapor intrusion issue and how it can impact the ap...

317

A Novel Datamining Based Approach for Remote Intrusion Detection  

Directory of Open Access Journals (Sweden)

Full Text Available Today, as information systems are more open to the Internet,attacks and intrusions are also increasing rapidly so the importance of secure networks is also vital. New intelligent Intrusion Detection Systems which are based on sophisticated algorithms are in demand.Intrusion Detection System (IDS is an important detection used as a countermeasure to preserve data integrity and system availability from attacks. It is a combination of software and hardware that attempts to perform intrusion detection.In data mining based intrusion detection system, we should make use of particular domain knowledge in relation to intrusion detection in order to efficiently extract relative rules from large amounts of records.This paper proposes boosting method for intrusion detection and it is possible to detect the intrusions in all the Systems, without installing the Software in client System (like client-server via Web service (Apache tomcat by using the ip address of the client system.

Renu Deepti.S, Loshma.G

2012-06-01

318

A network-based realtime intrusion detection system  

International Nuclear Information System (INIS)

The author first reviews the background of Intrusion Detection (ID), then discusses the models and classifications of Intrusion Detection System (IDS). After detail the basic concepts to realize network-based realtime IDS, the analysis of authors' work are presented

2000-09-07

319

Automated electronic intruder simulator for evaluation of ultrasonic intrusion detectors  

Energy Technology Data Exchange (ETDEWEB)

An automated electronic intruder simulator for testing ultrasonic intrusion detectors is described. This simulator is primarily intended for use in environmental chambers to determine the effects of temperature and humidity on the operation of ultrasonic intrusion detectors.

1979-01-01

320

Airborne vs ground magnetics for intrusion delineation in the Hunter  

Energy Technology Data Exchange (ETDEWEB)

The way in which ground magnetic surveys can reliably detect typical basaltic Hunter Valley intrusions is discussed. The effectiveness of magnetic methods in detecting intrusions of particular depth and thickness is considered. Comparisons with magnetic surveys are made. 2 tabs.

McClelland, P. [Ultramag Geophysics Pty Ltd, Marks Point, NSW (Australia)

1999-07-01

 
 
 
 
321

Automated electronic intruder simulator for evaluation of ultrasonic intrusion detectors  

International Nuclear Information System (INIS)

An automated electronic intruder simulator for testing ultrasonic intrusion detectors is described. This simulator is primarily intended for use in environmental chambers to determine the effects of temperature and humidity on the operation of ultrasonic intrusion detectors

1979-01-01

322

Adsorption behavior of Am(III) on granite  

International Nuclear Information System (INIS)

The adsorption behavior of Am(III) on granite (sampled from drilling well BS01 at Beishan (BS) area--a potential candidate site for China's high-level radioactive waste repository, the granite sample's depth about 300 m) was studied in BS03 well groundwater by a batch technique at (25±1) degree C. The influences of pH, sulphate ion, total carbonate ion, humic acid, and concentration of the Am(III) on the adsorption behavior were also studied, and the possible adsorption mechanism was discussed. Experimental results show that the adsorption distribution rate of Am(III) on granite increases with increasing pH of aqueous phase. The chemical composition of the groundwater is the main factor which influences the species of Am(III) and adsorption behavior. The adsorption mechanism of Am(III) on granite is surface complexation. The adsorption isotherm of Am(III) on granite can be described by Freundlich's equation. (authors)

2009-03-01

323

Territorial intrusion risk and antipredator behaviour: a mathematical model.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In territorial animals that hide to avoid predators, a predatory attack creates a conflict because a hiding animal cannot defend its territory from conspecific intruders. When intruders are persistent, a past conspecific intrusion informs a territorial resident that future intrusions by the same animal are likely. Using a mathematical model, I examine the effects that past territorial intrusions can have on antipredator behaviour. Past territorial intrusions rarely affect a resident animal's ...

Di?az-uriarte, R.

2001-01-01

324

A Frequency-Based Approach to Intrusion Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Research on network security and intrusion detection strategies presents many challenging issues to both theoreticians and practitioners. Hackers apply an array of intrusion and exploit techniques to cause disruption of normal system operations, but on the defense, firewalls and intrusion detection systems (IDS) are typically only effective in defending known intrusion types using their signatures, and are far less than mature when faced with novel attacks. In this paper, we adapt the frequen...

Mian Zhou; Sheau-Dong Lang

2004-01-01

325

An overview to Software Architecture in Intrusion Detection System  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Network intrusion detection systems provide proactive defense against security threats by detecting and blocking attack-related traffic. This task can be highly complex, and therefore, software-based network intrusion detection systems have difficulty in handling high speed links. This paper reviews of many type of software architecture in intrusion detection systems and describes the design and implementation of a high-performance network intrusion detection system that combines the use of s...

Mehdi Bahrami 1; Mohammad Bahrami

2011-01-01

326

Effective analysis of cloud based intrusion detection system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The goal of IDS is to analyze events on the network and identify attacks. The increasing number of network security related incidents makes it necessary for organizations to actively protect their sensitive data with the installation of intrusion detection systems (IDS). People are paid more attention on intrusion detection which as an important computer network security technology. According to the development trend of intrusion detection, detecting all kinds of intrusions effectively requir...

Sanjay Ram

2012-01-01

327

Simulation of network intrusion detection system with GPenSim  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In recent years, network has penetrated into every aspect of our life with its rapid growth and popularization. More and more serious network security problems have occurred together with this process, especially network intrusion problem. It has seriously affected the normal use of network, so research of network intrusion detection has become one of the hottest research areas. This thesis simulated a network intrusion detection system based on particle filter to solve the network intrusion ...

Liu, Bo

2011-01-01

328

Classification of the intrusion of terrigenous rocks into coal beds  

Energy Technology Data Exchange (ETDEWEB)

For predicting the increase in the intrusion of terrigenous rocks and for working out measures to prevent their harmful effect, the following classification of the intrusion forms was employed: Y-shaped, V-shaped, cup-shaped, downward expanding form ( a - with a visible inlet channel of material), b- without an inlet channel), band-shaped ( a - without a break in the intrusion continuity, b - with break in the intrusion continuity).

Shulga, V.F.; Vashenko, V.I.

1981-01-01

329

Chemical Observations of a Polar Vortex Intrusion  

Science.gov (United States)

An intrusion of vortex edge air in D the interior of the Arctic polar vortex was observed on the January 31,2005 flight of the NASA DC-8 aircraft. This intrusion was identified as anomalously high values of ozone by the AROTAL and DIAL lidars. Our analysis shows that this intrusion formed when a blocking feature near Iceland collapsed, allowing edge air to sweep into the vortex interior. along the DC-8 flight track also shows the intrusion in both ozone and HNO3. Polar Stratospheric Clouds (PSCs) were observed by the DIAL lidar on the DC-8. The spatial variability of the PSCs can be explained using MLS HNO3 and H2O observations and meteorological analysis temperatures. We also estimate vortex denitrification using the relationship between N2O and HNO3. Reverse domain fill back trajectory calculations are used to focus on the features in the MLS data. The trajectory results improve the agreement between lidar measured ozone and MLS ozone and also improve the agreement between the HNO3 measurements PSC locations. The back trajectory calculations allow us to compute the local denitrification rate and reduction of HCl within the filament. We estimate a denitrification rate of about lO%/day after exposure to below PSC formation temperature. Analysis of Aura MLS observations made

Schoeberl, M. R.; Kawa, S. R.; Douglass, A. R.; McGee, T. J.; Browell, E.; Waters, J.; Livesey, N.; Read, W.; Froidevaux, L.

2006-01-01

330

Distributed Approach of Intrusion Detection System: Survey  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion Detection Systems (IDS are now becoming one of burning issue for any organization’s network. Intruders always search for vulnerabilities or flaws in target system and attack using different techniques. An intrusion detection system (IDS is needed to detect and respond effectively whenever the confidentiality, integrity, and availability of computer resources are under attack. Today, number of open sources and commercial Intrusion Detection Systems are available to match organization’s requirements but the performance of these Intrusion Detection Systems is still the main concern. In this paper, we have analyzed the performance and applicability of the well knows IDS system based on mobile agent with their pros and cons. Mobile agent is efficient way to find out the intruder in distributed system. The main features of mobile agents are intelligence and mobility which is the core motivation to us to designed cost. The aim of this review work is to help to select appropriate IDS systems as per their requirement and application.

Vineet Richariya , Uday Pratap Singh , Renu Mishra

2012-12-01

331

Evolutionary Design of Intrusion Detection Programs  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion detection is the process of monitoring the events occurring in a computer system or network and analyzing them for signs of intrusions, defined as attempts to compromise the confidentiality, integrity, availability, or to bypass the security mechanisms of a computer or network. This paper proposes the development of an Intrusion Detection Program (IDP which could detect known attack patterns. An IDP does not eliminate the use of any preventive mechanism but it works as the last defensive mechanism in securing the system. Three variants of genetic programming techniques namely Linear Genetic Programming (LGP, Multi-Expression Programming (MEP and Gene Expression Programming (GEP were evaluated to design IDP. Several indices are used for comparisons and a detailed analysis of MEP technique is provided. Empirical results reveal that genetic programming technique could play a major role in develop- ing IDP, which are light weight and accurate when compared to some of the conventional intrusion detection systems based on machine learning paradigms.

Ajith Abraham

2007-05-01

332

An Adaptive Database Intrusion Detection System  

Science.gov (United States)

Intrusion detection is difficult to accomplish when attempting to employ current methodologies when considering the database and the authorized entity. It is a common understanding that current methodologies focus on the network architecture rather than the database, which is not an adequate solution when considering the insider threat. Recent…

Barrios, Rita M.

2011-01-01

333

How stratospheric are deep stratospheric intrusions?  

Directory of Open Access Journals (Sweden)

Full Text Available Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l. next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 and 2004. These investigations had been based on data filtering by using low relative humidity and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. For quantifying the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dew-point-mirror instrument at the Zugspitze summit station rarely registers relative humidity (RH values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are dryer by roughly one order of magnitude than indicated in the in-situ measurements. Even in thin layers frequently RH values clearly below 1% have been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO and, thus, the intrusion air mass originate in the shallow "mixing layer" around the thermal tropopause. The CO mixing ratio in these descending layers between 1990 and 2004 exhibits a slightly positive trend indicating some Asian influence on the lowermost stratosphere in the high-latitude source region of most intrusions reaching the station.

T. Trickl

2014-06-01

334

How stratospheric are deep stratospheric intrusions?  

Science.gov (United States)

Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l.) next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 and 2004. These investigations had been based on data filtering by using low relative humidity and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. For quantifying the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dew-point-mirror instrument at the Zugspitze summit station rarely registers relative humidity (RH) values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are dryer by roughly one order of magnitude than indicated in the in-situ measurements. Even in thin layers frequently RH values clearly below 1% have been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO and, thus, the intrusion air mass originate in the shallow "mixing layer" around the thermal tropopause. The CO mixing ratio in these descending layers between 1990 and 2004 exhibits a slightly positive trend indicating some Asian influence on the lowermost stratosphere in the high-latitude source region of most intrusions reaching the station.

Trickl, T.; Vogelmann, H.; Giehl, H.; Scheel, H.-E.; Sprenger, M.; Stohl, A.

2014-06-01

335

IRETHERM: Magnetotelluric Assessment of Geothermal Energy Potential of Hydrothermal Aquifer, Radiothermal Granite and Warm Spring Targets in Ireland  

Science.gov (United States)

IRETHERM (www.iretherm.ie) is an academic-government-industry, collaborative research project, funded by Science Foundation Ireland, with the overarching objective of developing a holistic understanding of Ireland's low-enthalpy geothermal energy potential through integrated modelling of new and existing geophysical and geological data. With the exception of Permo-Triassic basins in Northern Ireland, hosting geothermal aquifers of promising but currently poorly-defined potential, rocks with high primary porosity have not been identified elsewhere. Whether any major Irish shear zones/faults might host a geothermal aquifer at depth is also unknown, although clusters of warm-springs in the vicinity of two major shear zones are promising. IRETHERM's objectives over a four-year period are to: (i) Develop multi-parameter geophysical modelling and interpretation software tools that will enhance our ability to explore for and assess deep aquifers and granitic intrusions. (ii) Model and understand temperature variations in the upper-crust. Firstly, by building a 3-D model of crustal heat-production based on geochemical analysis of surface, borehole and mid- to lower-crustal xenolith samples. Secondly, by modelling, using a fully self-consistent 3-D approach, observed surface heat-flow variation as a function of variation in the structure and thermal properties of the crust and lithosphere, additionally constrained by surface elevation, geoid, gravity, seismic and magnetotelluric (MT) data. (iii) Test a strategic set of eight "type" geothermal targets with a systematic program of electromagnetic surveys (MT, CSEM) across ten target areas. During 2012, IRETHERM collected over 220 MT/AMT sites in the investigation of a range of different geothermal target types. Here we present preliminary electrical resistivity modelling results for each target investigated and discuss the implications of the models for geothermal energy potential: 1. Rathlin Basin The only sedimentary strata in Ireland known to provide reliable primary porosity, supporting deep hydrothermal aquifers, are found in the Triassic Sherwood Sandstone Group and in the upper-Permian, preserved in several basins in Northern Ireland. Our survey over the Rathlin Basin aims to map the geometry of these strata at depth and assess their porosity and permeability characteristics. 2. Kilbrook warm spring. Kilbrook warm spring is characterised by the warmest spring waters in Ireland (24.8°C) and highest Total Dissolved Solids concentration. Our high-resolution AMT survey over this occurrence aims to image the subsurface fluid conduit systems that bring these waters to surface. 3. Leinster and Galway granites Many of Ireland's exposed granites are associated with high radioactive element concentrations, high radiogenic heat production (HP) values and elevated surface heat-flow (SHF). Surveys over two of these granites - the Leinster granite (SHF: 80 mWm-2, HP: 2-3 µWm-3) and the Galway granite (SHF: 65-77 mWm-2, HP: 4-7 µWm-3) - aim to define the geometry, volume and local/regional heating effect of the granites and assess their suitability for energy provision using EGS. The models will also be assessed for indications of naturally occurring hydrothermal aquifers associated with either major faults that cross-cut the granites or the granite-country rock contacts.

Jones, Alan G.; Muller, Mark; Fullea, Javier; Vozar, Jan; Blake, Sarah; Delhaye, Robert; Farrell, Thomas

2013-04-01

336

What Caused the Younger Dryas? An Assessment of Existing Hypotheses  

Science.gov (United States)

The Younger Dryas cold event (~12.9-11.7 ka) has long been viewed as the canonical abrupt climate event. It was originally attributed to northward retreat of the southern Laurentide Ice Sheet (LIS) and eastward routing of Lake Agassiz from the Mississippi River to the St. Lawrence River, with the attendant freshening of the North Atlantic causing a reduction in Atlantic meridional overturning circulation (AMOC) strength. This original hypothesis has now been questioned based on 1) LIS model simulations that suggest an abrupt Arctic discharge of freshwater as the trigger, and 2) new dates from the outlets of Lake Agassiz, which are interpreted as indicating that the lake had no outlet during most of the Younger Dryas. With regards to Arctic freshwater forcing, one LIS model simulation produced a 0.09 Sverdrup (Sv) pulse of freshwater to the Arctic Ocean at the start of the Younger Dryas forced by a linearly interpolated Greenland ice-core climate scheme. However, this pulse lasted Agassiz outlets have mainly used minimum limiting radiocarbon dates, exclusively in the case of the eastern outlet where Lake Agassiz freshwater was supposedly routed during the Younger Dryas. A strict interpretation of these dates demonstrates, however, that they are not in conflict with the original routing hypothesis. The oldest minimum limiting macrofossil date constraining the southern outlet requires abandonment prior to ~12.8 ka, with the oldest macrofossil date from the eastern outlet indicating it was open prior to ~12.6 ka (potentially prior to ~13 ka based on the oldest bulk radiocarbon date). This chronology agrees with runoff proxies from the mouths of the Mississippi and St. Lawrence Rivers, where multiple planktonic oxygen-isotope records indicate the abandonment of the southern outlet and five independent geochemical runoff proxies record the routing of Lake Agassiz freshwater to the eastern outlet at the start of the Younger Dryas. Geochemical modeling of these latter proxies suggests freshwater discharge increases to the North Atlantic of 0.06-0.12 Sv for the duration of the Younger Dryas, which is sufficient forcing to explain this cold event. AMOC-sensitive proxy records show Younger Dryas-like events during earlier deglaciations that were forced by similar magnitude changes in boreal summer insolation as during the last deglaciation, arguing against a unique bolide forcing of the Younger Dryas.

Carlson, A. E.; Clark, P. U.

2009-12-01

337

Tracing the magmatic/hydrothermal transition in regional low-strain zones: The role of magma dynamics in strain localization at pluton roof, implications for intrusion-related gold deposits  

Science.gov (United States)

Structural controls are critical during magmatic-to-hydrothermal transition in the formation of intrusion-related gold deposits. They may explain why only some parts of intrusions are mineralized and why only very few intrusions host large deposits. Moreover, most of these gold deposits postdate peak regional metamorphism and were formed in zones of relatively low strain. Indeed, the efficiency of structural gold traps is highest along favourably oriented intrusion/host-rock contacts where mechanical instability maintains high permeability in the cracked thermal aureole. This may be reinforced by melt injections from an underlying root zone. We present a structural analysis of the deformation features of a granite-pluton roof; large-scale dykes and a network of gold veins are intensively developed in this roof, recording a succession of mechanical instabilities. Our gravity survey underlines the presence of a pluton feeder zone located just beneath the mineralized network. It is argued that interferences between regional stress and melt injection in the feeder zone favoured the development of the network by strain located close to the granite roof. This stresses the role of mechanical instabilities triggered by the combined effects of regional stress and melt dynamics in determining the location and size of this type of gold deposit.

Gloaguen, Eric; Branquet, Yannick; Chauvet, Alain; Bouchot, Vincent; Barbanson, Luc; Vigneresse, Jean-Louis

2014-01-01

338

U-Th-Pb age in hydrothermal monazite applied in geochronological tin mineralization from Greisen zone of the Palanqueta granitic system, Bom Futuro deposit, Rondonia, Brazil  

International Nuclear Information System (INIS)

The ages of hydrothermal events responsible for tin mineralization in the granitic systems from the Rondonia Tin Province are poorly defined so far. Available K-Ar dating in Li-micas of greisens and veins yielded values around 965 Ma, younger than the late mineralized granites ages, around 990 Ma. Electron microprobe U, Th and Pb dating of hydrothermal monazite from the greisen zones of the Palanqueta plutonic system, Bom Futuro tin deposit, yielded an age of 997±48 Ma. Considering that: the K-Ar method is influenced by increasing temperature; critical temperature of Ar retention in micas is 300 deg C; and fluid inclusions and ae 18O studies indicate, respectively, trapping temperature above 300 deg C and cassiterite crystallization temperature above 400 deg C, we suggest that the K-Ar dating in micas from Rondonia tin deposits are indicative of cooling and closure of the hydrothermal systems. Therefore, ages obtained from U-Th-Pb data in hydrothermal monazite from greisen can be considered a good reference for the tin ore formation in the Bom Futuro deposit, associated with late to post-magmatic processes, and coeval with the end of crystallization of albite granite in the Palanqueta granitic system. (author)

2005-03-01

339

Total exploitation of an ornamental granite quarry  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we propose a methodology to estimate the recovery percentage for each of the products which can be obtained from the exploitation of an ornamental granite quarry: block, semiblock, masonry-transverse stone, and the smaller materials that can be used to obtain construction aggregates. This methodology ensures that quarry exploitation is exhaustive, thereby minimising the production of spoils and the consequent negative impact on the environment. The analysis is based on a detailed and exhaustive compilation of discontinuity data from the research fronts, which are then interpreted statistically and projected over the three weakness planes that are a particular feature of ornamental granite deposits. Using this information, and bearing in mind the minimum commercially viable sizes for each kind of granite, the corresponding recovery rates are calculated for each material in each plane. The results are then integrated using spatial techniques, and the result is an evaluation of quarry contents with a view to total exploitation. This methodology was applied to a quarry in the opening phase in order to carry out an a priori assessment of the economic feasibility of the quarry.

En este trabajo se propone una metodología para estimar el porcentaje de recuperación de cada uno de los productos que se pueden obtener en la explotación de una cantera de granito ornamental: bloque, semibloque, manpostería y per piaños, y material restante destinado a la obtención de áridos. De esta manera se logra un aprovechamiento integral de la cantera, evitándose la generación de estériles y el subsiguiente impacto ambiental producido por éstos. La metodología de análisis se basa en la recopilación detallada y exhaustiva de datos de discontinuidades en los frentes de investigación, que se interpretan estadísticamente y se proyectan sobre los tres planos de debilidad propios del granito ornamental. Con esta información, y las dimensiones mínimas comerciales de referencia para cada tipo de material, se realiza el cálculo de las recuperaciones correspondientes de cada material en cada plano y los resultados de recuperación sobre estos tres planos se integran mediante técnicas espaciales; obteniéndose la evaluación de los recursos en la cantera para su aprovechamiento integral. La metodología ha sido aplicada a una cantera en fase de apertura para realizar una valoración inicial de su viabililidad económica.

Taboada, J.

2005-09-01

340

The Neoproterozoic Hongliujing A-type granite in Central Tianshan (NW China): LA-ICP-MS zircon U-Pb geochronology, geochemistry, Nd-Hf isotope and tectonic significance  

Science.gov (United States)

Located between the Turpan-Hami, Junggar and Tarim blocks, the Central Tianshan zone is an important component of the Central Asian Orogenic Belt (CAOB) and crucial linkage between the Siberian, Kazakhstan, Junggar, Turpan-Hami and Tarim blocks. The Hongliujing granite associated with Nb-Ta mineralization in the Central Tianshan zone, dated at ca. 740 Ma using zircon LA-ICP-MS dating, is the first reported Neoproterozoic intrusion with a reliable and precise age in the Chinese Central Tianshan. The Hongliujing granite shares all the characteristics of A-type granites. It contains predominant alkali feldspar, and is characterized by high contents of SiO2, Na2O + K2O, K2O and high field strength elements (such as Nb, Ta, Zr, Ga and Y), and low contents of CaO, MgO, Ba and Sr, with high FeOt/(FeOt + MgO) and Ga/Al ratios typical of A-type granites. Based on the geochemistry and zircon Hf isotope data, we propose that the Hongliujing granite was most likely produced by partial melting of basic rocks in the lower crust which may have been derived from mantle magmas. The Hongliujing granite belongs to A1-type granites, which indicate a rifting formation environment, suggesting that like the Tarim Block, the Central Tianshan zone recorded Neoproterozoic rift-related igneous events related to the breakup of the Rodinia supercontinent. Our study verifies that not only the Tarim Block is related to the breakup of the Rodinia supercontinent, but also it is true for some key blocks in CAOB such as the Central Tianshan. Our new geochemical and geochronologic data also support and strengthen the notion that the Central Tianshan zone may be a part of the Tarim Block.

Lei, Ru-Xiong; Wu, Chang-Zhi; Chi, Guo-Xiang; Gu, Lian-Xing; Dong, Lian-Hui; Qu, Xun; Jiang, Yao-Hui; Jiang, Shao-Yong

2013-09-01

 
 
 
 
341

Chemistry of deep groundwaters from granitic bedrock  

International Nuclear Information System (INIS)

Water analysis data from Fjaellveden, Gideaa, Svartboberget and Kamlunge (7 different drilling holes, 26 sampling levels at vertical depths between 100 and 600 m) are discussed. Most of the waters are Na(sup)+ -Ca2(sup)+ -HCO3(sup)- -dominated with a total salt content of 200-300 mg/1 and pH of 8-9. Intrusions of Na(sup)+ -Cl(sup)- -dominated saline waters (up to 650 mg/1) are observed at great depth. The conditions are generally strongly reducing. The presence of clayish material (kaolinite, smectities) and zeolites in the fractures appears to have a large influence on the cation concentration ratios. The contents of organics, largely fulvic acids of intermediate molecular weight (180 and deuterium) indicate a non-marine origin of the water and only minor exchanges with the surroundings. The presence of tritium is evidence of intrusions of young waters in some of the samples, probably due to the disturbances during drilling and sampling. (author)

1983-01-01

342

Petrology and geochemistry of the proterozoic A-type granite of Kanigiri, Prakasam dist., Andhra Pradesh, India: implications for rare metal mineralisation  

International Nuclear Information System (INIS)

The granite pluton (6.2x2.1 km2; 995±20 Ma) at Kanigiri, Prakasam district of Andhra Pradesh constitutes the southernmost part of the Prakasam alkaline complex (PAC). PAC lies to the east of the eastern margin of the Cuddapah basin, with the Dharwar schists and gneisses to its west and the eastern ghat mobile belt to its east, and is bound by two major deep faults. It comprises silica-undersaturated nepheline syenites at Elchuru, Purimetla, and Uppalapadu, saturated syenites at Settupalli, and oversaturated granitic rocks at Kanigiri and Podili. The Kanigiri granite (KG) occurs close to a major fault represented by the NW-SE flowing Mekeru river and is intrusive into the Dharwar schists, with xenoliths of the latter in the former. Petrographically, KG is a biotite granite (s.s.) with notable content of accessory minerals like fluorite and rare metal bearing minerals viz., columbite, samarskite, fergusonite, zircon, allanite, and thorite. Geochemically, it is a low Ca, metaluminous, highly fractionated alkali granite, with enrichment of Rb, Pb, Ga, Y, Zr, U, Th, Nb, and Ta, and depletion of Ba, Sr, Ti, and P. The field, petromineralogical, and geochemical aspects indicate KG as A-type (anorogenic; within plate), with (a) affinity to abortive rift-/hot spot-related continental epirogenic uplifted granitoid (CEUG) and (b) its parental melt derived by low degree partial melting of lower crustal mafic rocks at ca. 800 degC and emplaced with a near minimum melt composition at about 650 deg - 700 degC at PH2O of 5 kb (assumed). This neoproterozoic A-type CEUG is fertile for rare metals and soils derived from it are potential for polymetallic (Y, REE, Nb, and Ta) minerals. (author). 27 refs., 11 figs., 3 tabs

1996-10-01

343

Sorption of actinides in granitic rock  

International Nuclear Information System (INIS)

The sorption of americium (III), neptunium(V) and plutonium on geologic media under oxic conditions has been measured by a batch technique. The aqueous phase was a synthetic groundwater or 4M NaCl solution. The solid phase was a pure mineral, representative of igneous rocks, or granite. Altogether 40 different minerals and rocks were used. The effects of pH and the ionic strength of the aqueous phase as well as of the cation exchange capacity and the surface/mass ratio of the solid sorbent are discussed. Empirical equations giving the distribution coefficient as a function of pH in the environmental pH-range 7-9 are suggested. Some observations and conclusions concerning sorption mechanisms are given. (author)

1982-01-01

344

Alkaline lixiviation of uranium in granitic pegmatite  

International Nuclear Information System (INIS)

The work described herein concerns the determination of the experimental optimum conditions for the alkaline lixiviation of uranium based on the following parameters: time, pH, temperature, density and grane size. The samples were obtained from the Supamo complex, near the Currupia river in the Piar District of the Bolivar State in Venezuela. They have a granitic composition and graphitic texture. The uranium was found in them as a secondary oxidized mineral of green-yellow colour localized in fractures fissures, intergranular spaces and also in the mica as. Secondary uranitite. The lixiviation process was carried out using Na_2CO_3/NaHCO_3 buffer solution and for 100 gr. samples the best values for an efficient process were found by using 170 mesh grane size and 500 ml of pH buffer at 70"0C for a 24 hour time period. (author)

1980-01-01

345

Diffusion data in granite. Recommended values  

International Nuclear Information System (INIS)

Diffusion data for radionuclide transport in the porous matrix of rock are proposed for Swedish rock and ground waters, for performance assessment. Suggested data are based on an experimental diffusion study, where tritiated water was used as noninteracting diffusing species in stationary diffusion experiments in Aespoe fine grained granite and diorite. These data, for tritiated water, were used as reference in our study. For other species the effective diffusivities could be predicted from knowledge of the relative behaviour of these species to that of tritiated water. The behaviour is influenced by the difference in free water diffusivity and sometimes the existence of anion exclusion of surface diffusion. Apparent diffusivities are also calculated using sorption data, in addition to the effective diffusivities. Data are proposed for high saline and low saline ground water conditions

1997-01-01

346

Diffusion data in granite. Recommended values  

Energy Technology Data Exchange (ETDEWEB)

Diffusion data for radionuclide transport in the porous matrix of rock are proposed for Swedish rock and ground waters, for performance assessment. Suggested data are based on an experimental diffusion study, where tritiated water was used as noninteracting diffusing species in stationary diffusion experiments in Aespoe fine grained granite and diorite. These data, for tritiated water, were used as reference in our study. For other species the effective diffusivities could be predicted from knowledge of the relative behaviour of these species to that of tritiated water. The behaviour is influenced by the difference in free water diffusivity and sometimes the existence of anion exclusion of surface diffusion. Apparent diffusivities are also calculated using sorption data, in addition to the effective diffusivities. Data are proposed for high saline and low saline ground water conditions. 38 refs, 6 figs, 4 tabs.

Ohlsson, Yvonne; Neretniks, I. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

1997-10-01

347

Cognitive and affective empathy in younger and older individuals.  

Science.gov (United States)

Objective: We aimed to elucidate how cognitive and affective empathy differ across age groups and how these differences might relate to executive dysfunction. Methods: In study I, we assessed 108 healthy participants in three consecutive age groups (20-39 years/40-59 years/60-79 years) using a self-report measure of trait cognitive and affective empathy (interpersonal reactivity index: IRI). In study II, 54 younger (20-35 years) and 54 older (55-70 years) individuals completed a test of state cognitive and affective empathy (multifaceted empathy test: MET). Additionally, measures of cognitive flexibility, response inhibition, and working memory were administered. Results: Older and younger adults were comparable with regard to trait empathy (study I). Contrary to most previous findings, older adults did not show impaired state-cognitive empathy, but scored higher on subtests of state-affective empathy relative to the younger group, irrespective of the valence of the stimulus material (study II). Performance on the executive subtests was related to empathy in both studies. Discussion: While older and younger cohorts might not differ with regard to trait empathy, and state-cognitive empathy performance might be task-dependent, this investigation provides first evidence of potentially increased state affective empathic responding in older age. This might be related to executive dysfunction, in particular poor inhibitory control. PMID:24827596

Ze, Oksana; Thoma, Patrizia; Suchan, Boris

2014-09-01

348

Intrusion detection networks a key to collaborative security  

CERN Document Server

The rapidly increasing sophistication of cyber intrusions makes them nearly impossible to detect without the use of a collaborative intrusion detection network (IDN). Using overlay networks that allow an intrusion detection system (IDS) to exchange information, IDNs can dramatically improve your overall intrusion detection accuracy.Intrusion Detection Networks: A Key to Collaborative Security focuses on the design of IDNs and explains how to leverage effective and efficient collaboration between participant IDSs. Providing a complete introduction to IDSs and IDNs, it explains the benefits of b

Fung, Carol

2013-01-01

349

A Model of Intrusion Tolerant System Based on Game Theory  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusion tolerance is the rising third generation technology of network security. For the shortcomings of existing models, a model of intrusion tolerant system based on game theory is proposed. The intrusion tolerant system and the intruder are seen as the two sides of the game. The income functions of the two sides are designed basing on some given concepts. Through quantifying and analyzing the income functions, the optimum strategies of the intrusion tolerant system and the intruder are obtained, and the Nash equilibrium of the game system is achieved finally. The results of analysis show that, this proposed model of intrusion tolerant system is consistent with the practical system.

Huawang Qin

2009-04-01

350

Lithium Isotopes; a Potential aid to Understanding Granite Petrogenesis  

Science.gov (United States)

Significant enrichment in 6Li occurs during the weathering of continental crustal materials to clays, contributing to depleted ?7Li in the resultant sedimentary rocks. As such Li isotopes potentially provide a unique perspective on the nature of crustal components involved granite genesis. Carboniferous-Permian granites of the New England Batholith (NEB), Australia, emplaced in a Devonian-Triassic arc setting, are subdivided into 5 major supersuites1. Bundarra and Hillgrove are both S-types, interpreted to be derived from strongly weathered arc rocks1, and immature greywackes2, respectively. Moonbi, Uralla and Clarence River represent three distinct I-type supersuites. Moonbi granites are high-K and strongly oxidised. Uralla granites are medium-high-K, and more reduced. Clarence River are low-K, isotopically primitive granites, equivalent to arc magmas. Li isotopes were evaluated using MC-ICP-MS analysis under conditions of reduced RF power. This 'cool' plasma technique yields precision equivalent to TIMS (2\\sigma SD; 0.5‰ , 680W; 0.7‰ , 800W)3. Overall variations of ~10‰ ? 7Li are observed, greater than the differences observed in arc lavas worldwide (? 7Li = ~2 to 7‰ ). Clarence River granites typically have ?7Li > 4‰ , similar to lavas from sediment poor island arcs (e.g. Izu-Bonin and Kuriles). Bundarra granites have low ?7Li, consistent with involvement of more strongly weathered source components. The higher ?7Li (JAAS.

Bryant, C.; Chappell, B.; Bennett, V.

2002-12-01

351

Thermal Properties of Granite from KAERI Underground Research Tunnel (KURT)  

Energy Technology Data Exchange (ETDEWEB)

To obtain the input data for the design and long-term performance assessment of a high-level waste repository, the thermal properties of several granite rocks were measured. The granite rock samples were taken from the rock cores from the declined borehole. It was intended to propose the simple empirical correlation and quantitative model to predict the thermal properties of granite as a function of effective porosity and water content. For the dry samples, the thermal conductivities range from 2.12 W/mK for the rocks with a high porosity to 3.12 W/mK for the ones with a low porosity. Water-sorbed samples have greater thermal conductivities than dry samples of the same granite. The thermal conductivities range from 2.99 W/mK for granites with a high porosity to 3.62 W/mK for ones with a low porosity under saturated condition. An empirical correlation and quantitative model were proposed to predict the thermal conductivity and specific heat of granite as a function of porosity and water content. The correlation can predict the thermal conductivity and specific heat of granite with an estimated error below 10 % and 5 % respectively

Cho, Won Jin; Kwon, Sang Ki; Lee, Jae Owan [KAERI, Daejeon (Korea, Republic of)

2010-11-15

352

Granitic rocks from the southern Gyeongsang basin, southeastern Korea, (1)  

International Nuclear Information System (INIS)

In southern Gyeongsang basin, southeastern Korea, there are many granitic rock masses. They were divided into 7 groups according to their geological evidences. K-Ar age was determined on 36 samples obtained from the respective groups. Group A: pre-Gyeongsang granitic rock (Pre-Cretaceous), A_1 220 m.y., A_2 166 m.y.; group B: outer zone granitic rock (Cretaceous), 115-72 m.y.; group C: ditto (ditto), 97-70 m.y.; group D: ditto (ditto), 89-68 m.y.; group E: ditto (ditto), 82-68 m.y.; group F: inner zone granitic rock (Cretaceous), 75-74 m.y.; group G: Tertiary granitic rock, 63-41 m.y. The large part of the Cretaceous granitic masses show the double elongated ring form. Most of the Tertiary granitic rocks were probably emplaced in close relation with the Eonyang fault line and Ulsan fault line/or their extension line of the area. (J.P.N.)

1980-01-01

353

On Younger Stakeholders and Decommissioning of Nuclear Facilities  

International Nuclear Information System (INIS)

In modern democratic countries, information sharing and effective and open communication concerning dismantling and decommissioning of of nuclear facilities as well as the management of nuclear waste are essential for the task to build the confidence required for any further development of nuclear energy. At the same time, it is often perceived that all decision making processes about nuclear energy policies are probably increasingly influenced by public opinion. Nuclear and radiation safety Authorities have a clear role in this regard to provide unbiased information on any health and safety related issues. In order to meet this need, it is necessary for Authorities and others to understand the values and opinions of the citizens, and especially the younger ones. They hold the key to the future at the same time as their perspective on these issues is the least understood. The need of greater public participation in decision making is becoming increasingly recognised the scientific as well as the political community. Many activities are carried out in order to stimulate to higher levels of public involvement in decision making in this active research area. Younger citizens is a stakeholder group that is often excluded in decision- making processes. The existence of large gaps between the involvement of older and younger stakeholders in decision making processes needs to be addressed, since such imbalances might otherwise lead to unequal opportunities between generations and limit the future consumption level of the coming generations. Another demanding task for the present generation is to assure that appropriate financial resources are injected into the Swedish Nuclear Waste Fund. It will thereby be possible for coming generations to undertake efficient measures in the decommissioning and dismantling of older nuclear facilities. To undertake such measures in line with the environmental and health codex is essential. An appropriate balance in this regard must be based on a proper understanding of the values and value functions of younger citizens. Such information must thus be an integral part of the knowledge base to be used when plans and processes are being developed for dismantling and decommissioning of nuclear power plants and other older nuclear facilities. In the present project, empirical data have been collected and compiled in a survey of the values of younger citizens with regard to decommissioning and dismantling of older nuclear facilities. The survey constitutes a stratified sample from three towns in Poland. They are Lublin, Olsztyn and Gdansk. A total of 780 students in the age group 14-19 years participated in the Survey. The results are compared to those from a similar study in the County of Kalmar in Sweden in the year 2006. The results include some major lesson learned. These may be summarised as follows: - Younger citizens tend to base their values regarding decommissioning on safety, and environmental aspects. Aspects like future economic growth and technological processes are less influential on the values. - Younger citizens tend to express a lack of information and debate as a basis of their value functions. Likewise, they tend to express interest in the topic and are open to become more included in the processes. - Younger citizens have suggestions on how more information can be made accessible to the general public. - Younger citizens need to be better included in the stakeholder process. This can be achieved by allowances from the Swedish Nuclear Waste Fund to support groups of younger citizens to follow the Swedish process of research, development and demonstration of a concept for the management of spent nuclear fuel. Less than fully accessible information campaigns about nuclear power and associated nuclear waste may result in differences in confidence levels between different groups of stakeholders. By finding out more about the values of different stakeholders it will be possible for the Swedish Radiation Safety Authority as well as for Society as a whole to enhance the possibility t o de

2009-01-01

354

On Younger Stakeholders and Decommissioning of Nuclear Facilities  

Energy Technology Data Exchange (ETDEWEB)

In modern democratic countries, information sharing and effective and open communication concerning dismantling and decommissioning of of nuclear facilities as well as the management of nuclear waste are essential for the task to build the confidence required for any further development of nuclear energy. At the same time, it is often perceived that all decision making processes about nuclear energy policies are probably increasingly influenced by public opinion. Nuclear and radiation safety Authorities have a clear role in this regard to provide unbiased information on any health and safety related issues. In order to meet this need, it is necessary for Authorities and others to understand the values and opinions of the citizens, and especially the younger ones. They hold the key to the future at the same time as their perspective on these issues is the least understood. The need of greater public participation in decision making is becoming increasingly recognised the scientific as well as the political community. Many activities are carried out in order to stimulate to higher levels of public involvement in decision making in this active research area. Younger citizens is a stakeholder group that is often excluded in decision- making processes. The existence of large gaps between the involvement of older and younger stakeholders in decision making processes needs to be addressed, since such imbalances might otherwise lead to unequal opportunities between generations and limit the future consumption level of the coming generations. Another demanding task for the present generation is to assure that appropriate financial resources are injected into the Swedish Nuclear Waste Fund. It will thereby be possible for coming generations to undertake efficient measures in the decommissioning and dismantling of older nuclear facilities. To undertake such measures in line with the environmental and health codex is essential. An appropriate balance in this regard must be based on a proper understanding of the values and value functions of younger citizens. Such information must thus be an integral part of the knowledge base to be used when plans and processes are being developed for dismantling and decommissioning of nuclear power plants and other older nuclear facilities. In the present project, empirical data have been collected and compiled in a survey of the values of younger citizens with regard to decommissioning and dismantling of older nuclear facilities. The survey constitutes a stratified sample from three towns in Poland. They are Lublin, Olsztyn and Gdansk. A total of 780 students in the age group 14-19 years participated in the Survey. The results are compared to those from a similar study in the County of Kalmar in Sweden in the year 2006. The results include some major lesson learned. These may be summarised as follows: - Younger citizens tend to base their values regarding decommissioning on safety, and environmental aspects. Aspects like future economic growth and technological processes are less influential on the values. - Younger citizens tend to express a lack of information and debate as a basis of their value functions. Likewise, they tend to express interest in the topic and are open to become more included in the processes. - Younger citizens have suggestions on how more information can be made accessible to the general public. - Younger citizens need to be better included in the stakeholder process. This can be achieved by allowances from the Swedish Nuclear Waste Fund to support groups of younger citizens to follow the Swedish process of research, development and demonstration of a concept for the management of spent nuclear fuel. Less than fully accessible information campaigns about nuclear power and associated nuclear waste may result in differences in confidence levels between different groups of stakeholders. By finding out more about the values of different stakeholders it will be possible for the Swedish Radiation Safety Authority as well as for Society as a whole to enhance the possibility t o de

Tyszkiewicz, Bogumila; Labor, Bea

2009-08-15

355

Oxygen isotope use in the metallogenetic study of the Pedra Preta W mine, Musa Granite, Para State, Brazil  

International Nuclear Information System (INIS)

The Pedra Preta wolframite deposit constitutes the main reserve of the Amazonian region, Brazil. Recent metallogenetic studies realized in the mine, allowed to identify four hydrothermal events related to the precocious, late and final vein formation. The first are of the metamorphic origin and basically composed of quartz, topaz and sulfide; the late veins are related to the Musa granite intrusion and are composed of quartz, topaz, fluorite, micas, sulfides and oxides (principally wolframite); the final veins are essentially constituted by quartz. The paper determines the characteristics isotopic signatures of different minerals found in the Pedra Preta deposit. Fourteen samples were analysed, and the fluid isotopic composition were determined through the ?18 O measurement in quartz, micas and wolframite

1996-06-02

356

Clinical Analysis of Lung Cancer Patients Younger Than 30 Years  

Directory of Open Access Journals (Sweden)

Full Text Available Background and objective It is common recognized that young patients of lung cancer have poor prognosis due to relatively higher malignancy and more invasive growth. In the past most studies on young patients of lung cancer selected patients younger than 40 or 45 years old, and there were few clinical materials for younger patients under 30 years. This study retrospectively described the the disease history, stage, treatment and pathology features of lung cancer patients younger than 30 years and aimed to provide references for these patients. Methods Those patients younger than 30 years, once admitted in the General Hospital of the People's Liberation Army for lung cancer from 1993 to date, were sought in medical record system, and 53 patients were found in total. In this group, there were 34 non-small cell lung cancer (NSCLC patients and 19 small cell lung cacer (SCLC patients. The male/female ratio was 1.5:1. In the NSCLC patients, there were 27 adenocarcinomas, 6 squamous carcinomas and 1 adenosquamous carcinoma, with no large cell carcinoma involved. In these patients, 12 patients received operations while 38 patients got chemo- and/or radiotherapy and 3 quited any treatment. Results There was no death in hospital, however, in the 12 patients who got operation, only 8 patients got complete resection while 4 patients got palliative resection. Conclusion Lung cancer patients younger than 30 years had a high fraction of adenocarcinoma and small cell type pathologically and most of them were in late stage when presenting with symptoms in hospital and would have a dismal prognosis. The routine health examination and early diagnosis should be emphasized to improve the prognosis of these patients.

Guangjie HOU

2011-05-01

357

Comorbidities and Crash Involvement among Younger and Older Drivers  

Science.gov (United States)

Previous studies identified comorbidities as predictors of older driver performance and driving pattern, while the direct impact of comorbidities on road crash risk in elderly drivers is still unknown. The present study is a cross-sectional aimed at investigating the association between levels of comorbidity and crash involvement in adult and elderly drivers. 327 drivers were stratified according to age range in two groups: elderly drivers (age ?70 years old, referred as older) and adult drivers (age <70 years old, referred as younger). Driving information was obtained through a driving questionnaire. Distance traveled was categorized into low, medium and high on the basis of kilometers driven in a year. CIRS-illness severity (IS) and CIRS-comorbidity indices (CI) in all populations were calculated. Older drivers had a significantly higher crash involvements rate (p?=?.045) compared with the younger group based on the number of licensed drivers. Dividing comorbidity indices into tertiles among all licensed subjects, the number of current drivers significantly decreased (p<.0001) with increasing level of comorbidity. The number of current drivers among older subjects significantly decreased with increasing comorbidity level (p?=?.026) while no difference among younger group was found (p?=?.462). Among younger drivers with increasing comorbidity level, the number of road accidents significantly increased (p?=?.048) and the logistic regression analysis showed that comorbidity level significantly associated with crash involvement independent of gender and driving exposure. Older subjects with high level of comorbidity are able to self-regulate driving while comorbidity burden represents a significant risk factor for crash involvements among younger drivers.

Papa, Michela; Boccardi, Virginia; Prestano, Raffaele; Angellotti, Edith; Desiderio, Manuela; Marano, Luigi; Rizzo, Maria Rosaria; Paolisso, Giuseppe

2014-01-01

358

A Comprehensive Study in Data Mining Frameworks for Intrusion Detection  

Directory of Open Access Journals (Sweden)

Full Text Available Intrusions are the activities that violate the security policy of system. Intrusion Detection is the process used to identify intrusions. Network security is to be considered as a major issue in recent years, since the computer network keeps on expanding every day. An Intrusion Detection System (IDS is a system for detecting intrusions and reporting to the authority or to the network administration. Data mining techniques have been successfully applied in many fields like Network Management, Education, Science, Business, Manufacturing, Process control, and Fraud Detection. Data Mining for IDS is the technique which can be used mainly to identify unknown attacks and to raise alarms when security violations are detected. The purpose of this survey paper is to describe the methods/ techniques which are being used for Intrusion Detection based on Data mining concepts and the designed frame works for the same. We are also going to review the related works for intrusion detection.

R.Venkatesan, R. Ganesan, A. Arul Lawrence Selvakumar

2012-12-01

359

Intrusion Detection in Data Mining With Classification Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available In the research of intrusion detection there are so manyattacks in the real life and some IDS System to detect it like network-based IDS, host-based IDS and application-based IDS to detect the Intrusion. In this paper, one frame work is introduce to detect an intrusion data with the help of data mining, a framework for intrusion detection system for filtering data set to network attacks. We also talk about the basic data mining technology for finding intrusion data for the data set. Detection in the field of data mining for intrusion detection. We also discuss some of the common algorithms for intrusion detection, such as decision trees, Naive Bayes, Naive Bayes (CFSGSW, NBTree improved adaptive NBTree it.

PATEL HEMANT, BHARAT SARKHEDI, HIREN VAGHAMSHI

2013-07-01

360

Petrography and Geochemistry of the Dariyah Granite, Central Arabian Shield ????? ????? ???????????? ??????? ???? ???? ????? ??????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Dariyati granite, quarried for the use as a facade for the Holy Mosques in Makkah and AI-Madinah, belongs to the late-stage plutonics of the Arabian Shield (585 ± 8 Ma). It is a typicalleucocratic equigranular coarse-grained 'trans-solvus' granite formed dominantly of perthite, both orthoclase and microcline, quartz and 9ligoclase. Plagioclase crystallized first followed by potash feldspar then quartz. The granite is slightly peraluminous with low Ca, Mg, Fe and Ti contents. Its Ab-Qz-Or...

1992-01-01

 
 
 
 
361

The association of mafic ultramafic intrusions and A-type magmatism in the Tian Shan and Altay orogens, NW China: Implications for geodynamic evolution and potential for the discovery of new ore deposits  

Science.gov (United States)

The NW China region is characterised by tectonic and lithostratigraphic domains, such as the Tian Shan and Altay orogens, the Tarim, Junggar and Turpan Basins. The Tian Shan and Altay orogens are part of the Central Asian Orogenic Belt. The NW China region was affected by a series of thermal events that occurred between the Silurian and the Triassic, which resulted in the emplacement of numerous granitic plutons and mafic-ultramafic intrusions. A number of these granitic plutons are of A-type affiliation, which on the basis of the positive ?Nd values are likely to have been derived from mantle sources. In addition, at least two large igneous provinces (LIPs) can be recognised in NW China, namely the 345-325 Ma Tian Shan LIP and the ca. 270-280 Ma Tarim LIP. Age and field data suggest a spatial and temporal relationship between the mafic-ultramafic intrusions and A-type granites within the LIPs. In this paper we discuss mafic-ultramafic intrusions that host magmatic Ni-Cu sulphide deposits (Kalatongke in the Altay, Huangshan and Poyi-Poshi) in the eastern Tian Shan. These intrusions are typically zoned, characterised by an envelope of early gabbroic rocks that enclose later ultramafic units. These zoned mafic-ultramafic intrusions have some features that are comparable with Alaskan-type complexes. Taking into consideration the spatial-temporal relationship of the mafic, mafic-ultramafic rocks and A-type granites, we suggest that these magmatic events occurred during an extensional regime, possibly related to a mantle superplume event that affected much of central Asia during the Permian, of which the Siberian Traps and the Emeishan continental flood basalts of SW China are part. If the A-type felsic magmatism took place during a superplume event, we also suggest that these rocks may be conducive to host iron-oxide-copper-gold (IOCG) style mineralisation. We conclude with a model that attempts to explain the relationship between the zoned mafic-ultramafic intrusions and mantle plume activity in NW China during the Permian.

Pirajno, Franco; Mao, Jingwen; Zhang, Zhaochong; Zhang, Zuoheng; Chai, Fengmei

2008-03-01

362

Selective entrainment of peritectic garnet into S-type granitic magmas: Evidence from Archaean mid-crustal anatectites  

Science.gov (United States)

Entrainment of restite is commonly invoked to explain both the origin of relatively mafic granites and granodiorites, as well as the chemical connection between granite magmas and their sources. This concept has become linked to models for magma migration out of the source, as restite entrainment is considered to take place when diatexitic sources mobilise en masse. This is at odds with the common occurrence of relatively mafic granites as high level intrusions in the crust or their eruptive equivalents that must have formed from markedly water-undersaturated magmas that ascended through narrow conduits. We investigate pelitic migmatites from the Mkhondo Valley Metamorphic Suite (MVMS) in Swaziland, where a mid-crustal heating event produced metatexitic migmatites with minimal post-anatectic recrystallisation. In these rocks all the garnet is peritectic, having arisen through biotite fluid-absent melting, which produced garnet poikiloblasts characterised by inclusions of melt, quartz and biotite. Leucosomes that represent sites of melt transfer carry similar, smaller (typically < 1 mm), entrained garnet poikiloblasts, which were capable of amalgamating to form larger composite grains. In anatectic structures where melt was present for longer, entrained garnet was extensively recrystallised, via a dissolution-precipitation process, to adopt a more magmatic character. The peritectic garnet in the pelitic source appears to have grown out of equilibrium with feldspar and HREE-rich accessory phases, while the recrystallised garnet in the larger melt-filled structures became progressively better equilibrated with these minerals. Thus, peritectic garnet in the source grew sufficiently rapidly to prevent trace element equilibrium with the bulk-rock composition, and, concurrent rapid magma segregation prevented the development of diatexitic source conditions. The segregated magma consisted of melt, the peritectic assemblage (principally garnet) and the accessory minerals monazite and zircon. These rocks illustrate that mafic granites may arise purely as mixtures of melt and the peritectic assemblage produced by the incongruent melting reaction. Importantly, under the circumstances which produced the MVMS anatectites, peritectic garnet is entrained as < 1 mm poikiloblasts, demonstrating how mafic granitic magmas can migrate out of the source without the source becoming diatexitic.

Taylor, Jeanne; Stevens, Gary

2010-12-01

363

2005 dossier: granite. Tome: phenomenological evolution of the geologic disposal; Dossier 2005: Granite. Tome evolution phenomenologique du stockage geologique  

Energy Technology Data Exchange (ETDEWEB)

This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the phenomenological aspects of the geologic disposal of high-level and long-lived radioactive wastes (HLLL) in granite formations. Content: 1 - introduction: ANDRA's research program on disposal in granitic formation; 2 - the granitic environment: geologic history, French granites; 3 - HLLL wastes and disposal design concepts; 4 - identification, characterization and modeling of a granitic site: approach, geologic modeling, hydrologic and hydro-geochemical modeling, geomechanical and thermal modeling, long-term geologic evolution of a site; 5 - phenomenological evolution of a disposal: main aspects of the evolution of a repository with time, disposal infrastructures, B-type wastes disposal area, C-type wastes disposal area; spent fuels disposal area, radionuclides transfer and retention in the granitic environment; 6 - conclusions: available knowledge, methods and tools for the understanding and modeling of the phenomenological evolution of a granitic disposal site. (J.S.)

NONE

2005-07-01

364

Modernized Intrusion Detection Using Enhanced Apriori Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Communication networks are essential and it will create many crucial issues today. Nowadays, we consider that the firewalls are the first line of defense but that policies cannot meet the particular requirements of needed process to achieve security.Most of the research has been done in this area but we are lagging to achieve security needs. Already many models such as ADAM, DHP, LERAD and ENTROPHY are proposed to resolve security problems but we need an efficient model to detect new typesof various intrusions within the entire network. In this paper, we proposed to design a modernized intrusion detection system which consist of two methods such as anomaly and misuse detection. Both are integrated and also used to detect novel attacks. Our system proposed to discover temporal pattern of attacker behaviors, which is profiled using an algorithm EAA (Enhanced Apriori Algorithm. This is experimented with a simple interface to display the behaviors of attacks effectively.

Lalli

2013-05-01

365

Sensing Danger: Innate Immunology for Intrusion Detection  

CERN Document Server

The immune system provides an ideal metaphor for anomaly detection in general and computer security in particular. Based on this idea, artificial immune systems have been used for a number of years for intrusion detection, unfortunately so far with little success. However, these previous systems were largely based on immunological theory from the 1970s and 1980s and over the last decade our understanding of immunological processes has vastly improved. In this paper we present two new immune inspired algorithms based on the latest immunological discoveries, such as the behaviour of Dendritic Cells. The resultant algorithms are applied to real world intrusion problems and show encouraging results. Overall, we believe there is a bright future for these next generation artificial immune algorithms.

Uwe, Aickelin

2008-01-01

366

Data Reduction in Intrusion Alert Correlation  

CERN Multimedia

Network intrusion detection sensors are usually built around low level models of network traffic. This means that their output is of a similarly low level and as a consequence, is difficult to analyze. Intrusion alert correlation is the task of automating some of this analysis by grouping related alerts together. Attack graphs provide an intuitive model for such analysis. Unfortunately alert flooding att