Geochemical Identification of Windblown Dust Deposits in the Upper Permian Brushy Canyon Formation, Southern New Mexico

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Tice, M. M.; Motanated, K.; Weiss, R.

2009-12-01

Windblown dust is a potentially important but difficult-to-quantify source of siliciclastics for sedimentary basins worldwide. Positively identifying windblown deposits requires distinguishing them from other low density suspension transport deposits. For instance, laminated very fine grained sandstones and siltstones of the Upper Permian Brushy Canyon Formation have been variously interpreted as 1) the deposits of slow-moving, low-density turbidity currents, 2) distal overbank deposits of turbidity currents, 3) the deposits of turbulent suspensions transported across a pycnocline (interflows), and 4) windblown dust. This facies forms the bulk of Brushy Canyon Formation slope deposits, so understanding its origin is critical to understanding the evolution of the basin as a whole. We use a geochemical mapping technique (x-ray fluorescence microscopy) to show that these rocks are up to two times enriched in very fine sand sized zircon and rutile grains relative to Bouma A divisions of interbedded turbidites, suggesting substantial turbulence during transport. However, in contrast with the A divisions, the laminated sandstones and siltstones never show evidence of scour or amalgamation, implying that flow turbulence did not interact with underlying beds. Moreover, proximal loess deposits are often characterized by elevated Zr/Al2O3. These observations are most consistent with windblown interpretations for Brushy Canyon Formation slope sediments, and suggest that evolution of this early deepwater slope system was controlled largely by short-distance aeolian transport of very fine sand and silt from the coast. Heavy mineral incorporation into Brushy Canyon Formation slope deposits as reflected in laminae-scale bulk Zr and Ti abundances may preserve a long-term record of local wind intensity during the Upper Permian.

Sedimentology and stratigraphy of Neoproterozoic-lower Paleozoic carbonate-siliciclastic succession of the southwesternmost Amazon Craton, state of Rondônia, Brazil

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Jhon Willy Lopes Afonso

2018-02-01

Full Text Available ABSTRACT: Facies and stratigraphic analysis were carried out in Neoproterozoic-Lower Paleozoic carbonate-siliciclastic deposits of Cacoal and Pimenta Bueno formations exposed on basement rocks and into the Pimenta Bueno Graben, northwestern portion of Parecis Basin, southwesternmost Amazon Craton. The redescription and redefinion of this succession confirmed the previous interpretation for the Cacoal Formation as a Marinoan (~ 635 Ma cap carbonate. The Cacoal Formation is subdivided here in two units separate by sharp contact found exclusively overlying Mesoproterozoic crystalline basement rocks: 1 a homonymous formation characterized by diamictites, sandstones and siltstones with dropstones interpreted as glacio-marine deposits; and 2 the Espigão d’Oeste Formation that consists of dolostone, dolomitic stromatolites, dolostone-siltstone rhythmite and siltstone interpreted as shallow to moderately deep platform deposits. The Ordovician to Silurian Pimenta Bueno Formation is a filling of Pimenta Bueno graben and overlies locally the Meso and Neoproterozoic rocks. This unit consists in diamictites, sandstones, siltstones and pelites interpreted as glacial-marine and tide- to storm-influenced platform deposits, recording a glacio-eustatic regressive-transgressive event. This new stratigraphic proposal modify the current stratigraphy for the Parecis Basin and suggest, at least, two levels of glaciation exposed in the sothwesternmost Amazon Craton related to the Marinoan and Late Ordovician-Early Silurian events.

Slope-apron deposition in an ordovician arc-related setting: The Vuelta de Las Tolas Member (Suri Formation), Famatina Basin, northwest Argentina

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Mangano, M.G.; Buatois, L.A.

1997-01-01

The Ordovician Suri Formation is part of the infill of the Famatina Basin of northwest Argentina, which formed in an active setting along the western margin of early Paleozoic Gondwana. The lower part of this formation, the Vuelta de Las Tolas Member, records sedimentation on a slope apron formed in an intra-arc basin situated on a flooded continental arc platform. The coincidence of a thick Arenig-Llanvirn sedimentary succession and volcanic-plutonic arc rocks suggests an extensional or transtensional arc setting, and is consistent with evidence of an extensional regime within the volcanic arc in the northern Puna region. The studied stratigraphic sections consist of volcanic rocks and six sedimentary facies. The facies can be clustered into four facies associations. Association 1, composed of facies A (laminated siltstones and mudstones) and B (massive mudstones and siltstones), is interpreted to have accumulated from silty-muddy high-and low-density turbidity currents and highly fluid, silty debris flows, with subsequent reworking by bottom currents, and to a lesser extent, hemipelagic suspension in an open-slope setting. Facies association 2 is dominated by facies C (current-rippled siltstones) strata. These deposits are interpreted to record overbank sedimentation from fine-grained turbidity currents. Facies E (matrix-supported volcanic breccias) interbedded with andesitic lava units comprises facies association 3. Deposition was contemporaneous with subaqueous volcanic activity, and accumulated from cohesive debris flows in a coarse-grained wedge at the base of slope. Facies association 4 is typified by facies D (vitric fine-grained sandstones and siltstones) and F (channelized and graded volcanic conglomerates and breccias) deposits. These strata commonly display thinning-and fining-upward trends, indicating sedimentation from highly-concentrated volcaniclastic turbidity currents in a channelized system. The general characteristics of these deposits of fresh

Primary uranium mineralization in paleochannels of the Um Bogma formation at Allouga Southwestern Sinai

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Bisher, A. H.

2012-12-01

The Um Bogama formation in the Allouga area is within a major Graben trending NNW-SSE. The formation is composed mainly of sandy dolostone. Lactomicin marl, siltstone and carbonaceous shale with a high content of organic matter. The black carbonaceous shale represents the redox-front (reduced facies) at which hexavalent uranium can reduce to the presence state, resulting in the redeposition of uranium mineral. The presence of uranium minerals are increased with an increasing amount of carbonaceous matter in the paleochannels of the Allouga area. Small-scale fault planes also show an increase in the uranium content. The present study reveals the presence of the primary uranium contents, uranium, pitch blends and coffinite, which are recorded for the first time in the area. (Author)

Stratigraphic and structural data for the Conasauga Group and the Rome Formation on the Copper Creek fault block near Oak Ridge, Tennessee: preliminary results from test borehole ORNL-JOY No. 2

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Haase, C.S.; Walls, E.C.; Farmer, C.D.

1985-06-01

To resolve long-standing problems with the stratigraphy of the Conasauga Group and the Rome Formation on the Copper Creek fault block near Oak Ridge National Laboratory (ORNL), an 828.5-m-deep test borehole was drilled. Continuous rock core was recovered from the 17.7- to 828.5-m-deep interval; temperature, caliper, neutron, gamma-ray, and acoustic (velocity and televiewer) logs were obtained. The Conasauga Group at the study site is 572.4 m thick and comprises six formations that are - in descending stratigraphic order - Maynardville Limestone (98.8 m), Nolichucky Shale (167.9 m), Maryville Limestone (141.1 m), Rogersville Shale (39.6 m), Rutledge Limestone (30.8 m), and Pumpkin Valley Shale (94.2 m). The formations are lithologically complex, ranging from clastics that consist of shales, mudstones, and siltstones to carbonates that consist of micrites, wackestones, packstones, and conglomerates. The Rome Formation is 188.1 m thick and consists of variably bedded mudstones, siltstones, and sandstones. The Rome Formation thickness represents 88.1 m of relatively undeformed section and 100.0 m of highly deformed, jumbled, and partially repeated section. The bottom of the Rome Formation is marked by a tectonic disconformity that occurs within a 46-m-thick, intensely deformed interval caused by motion along the Copper Creek fault. Results from this study establish the stratigraphy and the lithology of the Conasauga Group and the Rome Formation near ORNL and, for the first time, allow for the unambiguous correlation of cores and geophysical logs from boreholes elsewhere in the ORNL vicinity. 45 refs., 26 figs., 2 tabs

Distribution of uranium in the carbonate rock of Um Bogma formation, Southwest, Sinai, Egypt

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El-AAssy, I.E.; Ahmed, F.Y.; Morsy, A.M.; El-Fawal, F.M.; Mansour, M.Gh.

1998-01-01

The lower carboniferous Um bogma Formation is a potential source for Mn, Cu and U. it is mainly composed of dolostone and limestone with few clastic different interbeds of clay stone, siltstone and sandstone. The different diagenetic processes which affected this formation are mainly, compaction, cementation, neomorphism, dissolution, dolomitization, silicification and filling the veins and pores. The distribution of uranium and thorium within the three members and their correlation with the iron oxides and organic matter, were studied. The channel porosity and intercrystalline spaces which resulted from dolomitization acted as pathways for uraniferous solutions in the carbonate rocks. On the other hand, the shales and clay stones underneath the carbonates of Um bogma formation acted as barriers and good depositional environment for the accumulation of uranium on the surfaces of joints and fractures.The accumulated uranium minerals in the carbonate rocks are most likely of the efflorescent deposits

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

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

2017-10-01

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

Araçatuba Formation: palustrine deposits from the initial sedimentation phase of the Bauru Basin

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Fernandes Luiz A.

2003-01-01

Full Text Available The Bauru Basin (Upper Cretaceous accumulated an essentially sandy continental sedimentary sequence. In a first desertic phase the basaltic substratum was covered by a widespread and homogeneous aeolian sand unit with minor loess intercalations. The substratum relief favored the formation of an endorheic drainage system under semi-arid climate, a process that started the development of the Araçatuba Paleoswamp. The palustrine deposits (Araçatuba Formation comprise siltstone and tipically greenish gray narrow tabular strata of sandstone cemented by carbonate. Moulds and gypsite and dolomite pseudomorphs were identified. The moulds seem to be genetically associated with desiccation cracks, root marks and climbing ripple lamination levels, that, on the whole, indicate calm shallow saline waters undergoing phases of subaerial exposition. At the boundaries of the study area, sand units may exhibit sigmoidal features and convolute bedding structure, which is characteristic of marginal deltaic deposits. The Araçatuba Formation is enclosed in and later overlaid by the aeolian deposits of the Vale do Rio do Peixe Formation.

Calcareous nannofossil biostratigraphy of Sarcheshmeh and Sanganeh formations at Qaleh Jegh and Yazdan Abad sections (West of Kopet-Dagh Basin

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Azam Gholami Fard

2017-03-01

Full Text Available 1-    Introduction Kopet Dagh Basin is located on the northeast of Iran, extending over Iran, Turkmenistan and Afghanistan with a west-northwest to east-southeast trend. The Iranian part of the basin is located between 61°14ˊ and 54°00ˊE and 38°15ˊ and 35°38ˊ N. It constitutes the second most important hydrocarbon province of Iran after Zagros Basin. Cretaceous sediments are well developed and extensively exposed in this basin. In order to study the Biostratigraphy of Sarcheshme and Sanganeh Formations, the calcareous nannofossil assemblages have been investigated in two stratigraphic sections. Shokri (2000, Hadavi and Shokri (2000, Hadavi and Bodaghi (2000 & 2009, Dehghan (2002, Mahanipour et al. (2011a,b & 2012 and Mahanipour and Kani (2015 studied the calcareous nannofossil biostratigraphy of Sarcheshme or Sanganeh Formation.   2-    Material & Methods The studied sections, the Qaleh Jegh section (located at a distance of 35 km to the northeast of Bojnord, on the Baba Boland mountain; N37°47ˊ57˝ and E57°16ˊ53˝ and Yazdan Abad section (located at north of Yazdan Abad village; N37°55ˊ34˝ and E57°35ˊ10˝. Sarcheshmeh Formation conformably overlies the Tirgan Formation and is in turn overlain by the Sanganeh Formation in both sections and Atamir Formation conformably overlies the Sanganeh Formation. Sarcheshmeh Formation measures 2660 m in Qaleh Jegh section and comprises argillaceous limestone (with limestone intercalations in lower part and shale (with limestone intercalation in upper part. A  fossiliferous limestone separates the Sarcheshmeh and Sanganeh. Sanganeh Formation measures 1400 m and consists of siltstones (with sandstone, shale or limestone intercalation in lower part and shale containing chert nodules (with siltstone intercalation in upper part. At Yazadn Abad section the 655 m thick succession of Sarcheshmeh Formation consists of alternating argillaceous limestone and limestone in lower part and

Lithostratigraphy of Upper Ordovician strata exposed in Kentucky

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Weir, Gordon Whitney; Peterson, Warren Lee; Swadley, W.C.

1984-01-01

Ordovician formations above the Lexington Limestone crop out in the Blue Grass region of Kentucky and along the Cumberland River and its tributaries. The formations are all conformable and in places intertongue and intergrade. The major Ordovician units above the Lexington Limestone in the Blue Grass region are: The Clays Ferry Formation, the Kope Formation, the Garrard Siltstone, the Fairview Formation, the Calloway Creek Limestone, the Grant Lake Limestone, the Ashlock Formation, the Bull Fork Formation, and the Drakes Formation. The Clays Ferry Formation is made up of subequal amounts of fossiliferous limestone and shale and minor siltstone; the Clays Ferry is as much as 300 ft thick and intertongues with the Lexington Limestone and the Kope Formation. The Kope Formation resembles the partly equivalent Clays Ferry but has a higher shale content (60-80 percent) and thicker layers of shale; the Kope, as much as 275 ft thick, is mostly restricted to the northern part of the State. The Garrard Siltstone, which consists of very calcitic siltstone and minor shale, overlies the Clays Ferry Formation in the southeastern part of the Blue Grass region; the Garrard, as much as 100 ft thick, feathers out into the upper part of the Clays Ferry in southern central and northern east-central Kentucky. The Fairview Formation is characterized by even-bedded limestone interlayered with nearly equal amounts of shale and minor siltstone. The Fairview crops out in the northern part of the Blue Grass region, where it generally overlies the Kope Formation or the Garrard Siltstone; it grades southward into the Calloway Creek Limestone. The Calloway Creek contains more limestone (generally at least 70 percent) and is more irregularly and thinner bedded than the Fairview. The Grant Lake Limestone is composed of nodular-bedded limestone (70-90 percent), interlayered and intermixed with shale; it overlies the Fairview Formation in the northern part of the Blue Grass region and the Calloway

A micropalaeontological and palynological insight into Early Carboniferous floodplain environments

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Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John; Reeves, Emma

2016-04-01

Romer's Gap, the interval following the end Devonian mass extinction, is traditionally considered to be depauperate in tetrapod and fish fossils. A major research project (TW:eed -Tetrapod World: early evolution and diversification) focusing on the Tournaisian Ballagan Formation of Scotland is investigating how early Carboniferous ecosystems rebuilt following the extinction. A multi-proxy approach, combining sedimentology, micropalaeontology and palynology, is used to investigate the different floodplain environments in which tetrapods, fish, arthropods and molluscs lived. The formation is characterised by an overbank facies association of siltstone, sandstone and palaeosols, interbedded with dolostone and evaporite units, and cut by fluvial sandstone facies associations of fining-upwards conglomerate lags, cross-bedded sandstone and rippled siltstone. Macrofossils are identified from 326 horizons within a 520 metre thick Ballagan Formation field section at Burnmouth, near Berwick-upon-Tweed, Scottish Borders. Common fauna are ostracods, bivalves, arthropods, sarcopterygians, dipnoans, acanthodians, tetrapods and chondrichthyans. Quantitative microfossil picking of the three sedimentary rock types in which tetrapods occur was undertaken to gain further insight into the palaeoecology. The sediments are; 1) laminated grey siltstones, deposited in floodplain lakes; 2) sandy siltstones, grey siltstones with millimetre size clasts. 71% of these beds overlie palaeosols or desiccated surfaces and are formed in small-scale flooding events; 3) conglomerates, mostly lags at the base of thick sandstones, with centimetre sized siltstone, sandstone and dolostone clasts. Grey siltstones contain a microfauna of common plant fragments, megaspores and sparse actinopterygian and rhizodont fragments. Sandy siltstones have the highest fossil diversity and contain microfossil fragments of plants, megaspores, charcoal, ostracods, actinopterygians, rhizodonts, eurypterids and rarer non

The magnetic polarity stratigraphy of the Mauch Chunk Formation, Pennsylvania.

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Opdyke, Neil D; DiVenere, Victor J

2004-09-14

Three sections of Chesterian Mauch Chunk Formation in Pennsylvania have been studied paleomagnetically to determine a Late Mississippian magnetic polarity stratigraphy. The upper section at Lavelle includes a conglomerate with abundant red siltstone rip-up clasts that yielded a positive conglomerate test. All samples were subjected to progressive thermal demagnetization to temperatures as high as 700 degrees C. Two components of magnetization were isolated: a synfolding "B" component and the prefolding "C" component. The conglomerate test is positive, indicating that the C component was acquired very early in the history of the sediment. A coherent pattern of magnetic polarity reversals was identified. Five magnetozones were identified in the upper Lavelle section, which yields a pattern that is an excellent match with the pattern of reversals obtained from the upper Mauch Chunk at the original type section of the Mississippian/Pennsylvanian boundary at Pottsville, PA. The frequency of reversals in the upper Mississippian, as identified in the Mauch Chunk Formation, is approximately one to two per million years, which is an average for field reversal through time.

Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Moyer, T.C.; Geslin, J.K.

1995-01-01

Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff

Lithostratigraphy of the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) at Yucca Mountain, Nevada

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Moyer, T.C.; Geslin, J.K. [Science Applications International Corp., Las Vegas, NV (United States)

1995-07-01

Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff.

Mineralogical investigations of the area to the North-West of Qattara Depression, Western Desert, Egypt

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Tosson, S.; Roshdy, H.M.K.

2000-01-01

Petrophysical and mineralogical investigations are given for subsurface samples from this area. The paper deals with mineralogical investigations of Middle Jurassic, Lower Cretaceous and Upper Cretaceous sedimentary rocks. It includes thin section examinations for 14 samples of sandstone, siltstone and carbonates, and x-ray powder diffraction analyses of some argillaceous samples, untreated and glycolated. It was found that the kaolinite group is the main clay mineral recorded in the argillaceous sandstone and siltstone samples. Illite and montmorillonite are identified in the shale sample representing the Kharita Formation. Siderite was also recorded in the sample. Illite and montmorillonite were recorded as well as kaolinite in two siltstone samples. (Author)

Organic-rich shale lithofacies geophysical prediction: A case study in the fifth organic-matter-rich interval of Paleogene Hetaoyuan Formation, Biyang Depression

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Fei, S.; Xinong, X.

2017-12-01

The fifth organic-matter-rich interval (ORI 5) in the He-third Member of the Paleogene Hetaoyuan Formation is believed to be the main exploration target for shale oil in Biyang Depression, eastern China. An important part of successful explorating and producing shale oil is to identify and predict organic-rich shale lithofacies with different reservoir capacities and rock geomechanical properties, which are related to organic matter content and mineral components. In this study, shale lithofacies are defined by core analysis data, well-logging and seismic data, and the spatial-temporal distribution of various lithologies are predicted qualitatively by seismic attribute technology and quantitatively by geostatistical inversion analysis, and the prediction results are confirmed by the logging data and geological background. ORI 5 is present in lacustrine expanding system tract and can be further divided into four parasequence sets based on the analysis of conventional logs, TOC content and wavelet transform. Calcareous shale, dolomitic shale, argillaceous shale, silty shale and muddy siltstone are defined within ORI 5, and can be separated and predicted in regional-scale by root mean square amplitude (RMS) analysis and wave impedance. The results indicate that in the early expansion system tract, dolomitic shale and calcareous shale widely developed in the study area, and argillaceous shale, silty shale, and muddy siltstone only developed in periphery of deep depression. With the lake level rising, argillaceous shale and calcareous shale are well developed, and argillaceous shale interbeded with silty shale or muddy siltstone developed in deep or semi-deep lake. In the late expansion system tract, argillaceous shale is widely deposited in the deepest depression, calcareous shale presented band distribution in the east of the depression. Actual test results indicate that these methods are feasible to predict the spatial distribution of shale lithofacies.

LITHOSTRATIGRAPHY, CONODONT BIOSTRATIGRAPHY AND DEPOSITIONAL ENVIRONMENT OF THE MIDDLE DEVONIAN (GIVETIAN TO EARLY CARBONIFEROUS (TOURNAISIAN LIPAK FORMATION IN THE PIN VALLEY OF SPITI (NW INDIA

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ERICH DRAGANITS

2002-03-01

Full Text Available Bed-by-bed lithostratigraphic sections combined with sequence stratigraphy and conodont biostratigraphy provide new information on the depositional environment and age of the Lipak Formation in the Pin Valley (Spiti. The formation comprises mixed siliciclastic and calcareous sediments at lower levels, richly fossiliferous limestones with two distinct sandstone incursions at higher levels, and dark mudstones followed by a thin siltstone interval. The upper limit of the Lipak Formation is defined by the angular unconformity below the sandstones of the Permian Gechang Formation. Lithologic correlation with sections in upper Lahaul indicates that, in the Pin Valley, the formation has been truncated just below its characteristic gypsum horizon. The lower boundary of the Lipak Formation is gradational from coastal arenites of the Muth Formation; the mappable boundary is drawn at the first appearance of dark carbonaceous, argillaceous siltstone and shale.Sedimentary structures, microfacies and conodont faunas indicate a general shallow marine depositional environment of the Lipak Formation in the Pin Valley; five sequence stratigraphic units have been distinguished. Conodont data demonstrate that the lowest 33 m of the Lipak Formation of the Pin Valley is mid to late Early varcus Subzone with characteristic species of Icriodus and Bipennatus. A previously unrecognised hiatus at c. 33 m above the base, at the boundary of sequence stratigraphic units S1 and S2, represents the interval Middle varcus Subzone to at least the end of the late Famennian Early expansa Zone. Because this hiatus does not correspond to a mappable boundary, no division of the Lipak Formation into named stratigraphic units is suggested, but we refer informally to the sediments represented by cycle S1 as Lipak A, and the sediments represented by cycles S2-S5 as Lipak B. Determination of S1 as Early varcus Subzone provides a maximum age for the gradationally underlying Muth Formation

Sedimentary and tectonic history of the Holowilena Ironstone, a Neoproterozoic iron formation in South Australia

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Lechte, Maxwell Alexander; Wallace, Malcolm William

2015-11-01

The Holowilena Ironstone is a Neoproterozoic iron formation in South Australia associated with glacial deposits of the Sturtian glaciation. Through a comprehensive field study coupled with optical and scanning electron microscopy, X-ray fluorescence, and X-ray diffraction, a detailed description of the stratigraphy, sedimentology, mineralogy, and structure of the Holowilena Ironstone was obtained. The Holowilena Ironstone comprises ferruginous shales, siltstones, diamictites, and is largely made up of hematite and jasper, early diagenetic replacement minerals of precursor iron oxyhydroxides, and silica. These chemical precipitates are variably influenced by turbidites and debris flows contributing clastic detritus to the depositional system. Structural and stratigraphic evidence suggests deposition within a synsedimentary half-graben. A model for the Holowilena Ironstone is proposed, in which dense oxic fluids expelled during sea ice formation in the Cryogenian pool in the depression of the half-graben, allowing for long-lived mixing with the ferruginous seawater and the deposition of iron oxides. This combination of glacial dynamics, tectonism, and ocean chemistry may explain the return of iron formations in the Neoproterozoic.

Nanggulan Formation and Its Problem As a Basement in Kulonprogo Basin, Yogyakarta

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Hill Gendoet Hartono

2017-03-01

Full Text Available DOI: 10.17014/ijog.4.2.71-80Nanggulan Formation consists of the oldest clastic rock sequence exposed in Kulonprogo area, Yogyakarta. This paper discusses the position of Nanggulan Formation as a basement. The method used in this research is surface and subsurface investigations based on gravity surveys. The rock assemblage is exposed and distributed partly in the east flank of Kulonprogo Mountains with weak undulated morphology. The rock sequence is composed of sand to clay grain sizes such as sandstone, quartz sandstone, calcareous sandstone, claystone, fossiliferous claystone, calcareous claystone, siltstone, and coal seam intercalations. The total thickness of the sequence is less than 200 m. Based on the fossil and palynology investigations, previous investigators concluded the age of the rock was Eocene to Middle Miocene. The geological structures developed in the rocks are the lithological stratification, fractures, folding, and faulting. The subsurface interpretation based on gravity data revealed the rock was located under the andesite breccias with 2.44 g/cc density. The density of the rock sequence was 2.63 g/cc. The gravity interpretation shows a strong indication that Nanggulan Formation underlies the andesitic breccias presumably associated with Old Andesite Formation exposed in Kulonprogo Mountains. The limited distribution, the thickness, and the closed environmental deposition of Nanggulan Formation found in the present investigation raised problems on the position of the formation as the basement of Old Andesite Formation occurring in the Kulonprogo Mountain.

Soft-sediment deformation structures from an ice-marginal storm-tide interactive system, Permo-Carboniferous Talchir Formation, Talchir Coalbasin, India

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Bhattacharya, H. N.; Bhattacharya, Biplab

2010-01-01

Permo-Carboniferous Talchir Formation, Talchir Coalbasin, India, records sedimentation during a phase of climatic amelioration in an ice-marginal storm-affected shelf. Evidences of subtidal processes are preserved only under thick mud drapes deposited during waning storm phases. Various soft-sediment deformation structures in some sandstone/siltstone-mudstone interbeds, like syn-sedimentary faults, deformed laminations, sand-silt flows, convolute laminations and various flame structures, suggest liquefaction and fluidization of the beds due to passage of syn-depositional seismic shocks. In the Late Paleozoic ice-marginal shelf, such earthquake tremors could be generated by crustal movements in response to glacioisostatic adjustments of the basin floor.

Petrological-geochemical characteristics of coarse-grained clastic sedimentary rocks of Quantou Formation, Cretaceous in Songliao basin and their geological significance

International Nuclear Information System (INIS)

Wang Gan; Zhang Bangtong

2005-01-01

Clastic sedimentary rocks of Quantou Formation, Cretaceous in Qing-an area, Songliao basin are mainly composed of sandstone, mudstone and siltstone. The petrological-chemical analysis of clastic sedimentary rocks from Quantou Formation, Cretaceous indicates that their lithology mainly consists of arkose, shale and minor rock debris sandstone and greywacke by chemical classification of bulk elements. REE distribution pattern displays the apparent enrichment of LREE and negative anomaly of Eu and is similar to that of NASC and PAAS. The ratio of trace-element in sedimentary rocks to that of upper crust shows gentle character. All the above features indicate that these sedimentary rocks were slowly deposited under weakly active tectonic setting. They are sediments typical for passive continental margin and active continental margin. It is suggested that material source of clastic sediments of Quantou Formation, Cretaceous in Qing-an area, Songliao basin was originated from Hercynian granite of Zhangguangchai Mountain, and the granite was originated from upper crust. (authors)

Permian storm current-produced offshore bars from an ancient shelf sequence : Northwestern Karoo basin, republic of South Africa

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Smith, A. M.; Zawada, P. K.

The Ecca-Beaufort transition zone from the Karoo Basin comprises upward-coarsening sequences which are interpreted as prograding, storm-produced offshore bars. Eight facies are recognised: (A) dark-grey shale, (B) thinly interbedded siltstone and mudstone, (C) thinly interbedded siltstone and very fine-grained sandstone, (D) blue-grey coarse-grained siltstone, (E) low-angle truncated and flat-laminated sandstone, (F) wave-rippled sandstone, (G) planar cross-bedded sandstone, (H) intraformational clay-pellet conglomerate. Four sub-environments are recognised, these being: (1) the bar crest which comprises proximal tempestites, (2) the bar slope consisting of soft-sediment deformed siltstone, (3) the bar fringe/ margin which is composed of storm layers and offshore siltstones and (4) the interbar/offshore environment comprising siltstone and distal storm layers. These bars formed in response to wave and storm processes and migrated across a muddy shelf environment. The orientation of bars was probably coast-parallel to subparallel with respect to the inferred north-northwest-south-southeast coastline. These proposed, storm-produced bars acted as major depo-centres within the shelf setting of the study area. As shelf sediments are recorded from almost the entire northwestern Karoo Basin it is anticipated that bar formation was an important sedimentary factor in the deposition of the sediments now referred to as the Ecca-Beaufort transition zone.

Utilizing borehole electrical images to interpret lithofacies of fan-delta: A case study of Lower Triassic Baikouquan Formation in Mahu Depression, Junggar Basin, China

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Yuan Rui

2017-11-01

Full Text Available Large-scale conglomerate fan-delta aprons were typical deposits on the slope of Mahu Depression during the Early Triassic. Without outcrops, it is difficult to study the lithofacies only by examining the limited cores from the main oil-bearing interval of the Baikouquan Formation. Borehole electrical imaging log provides abundant high-resolution geologic information that is obtainable only from real rocks previously. Referring to the lithology and sedimentary structure of cores, a case study of fan-deltas in the Lower Triassic Baikouquan Formation of the Mahu Depression presents a methodology for interpreting the complicated lithofacies utilizing borehole electrical images. Eleven types of lithologies and five types of sedimentary structures are summarized in borehole electrical images. The sediments are fining upward from gravel to silt and clay in the Baikouquan Formation. Fine-pebbles and granules are the main deposits in T1b1 and T1b2, but sandstones, siltstones and mudstones are more developed in T1b3. The main sedimentary textures are massive beddings, cross beddings and scour-and-fill structures. Parallel and horizontal beddings are more developed in T1b3 relatively. On integrated analysis of the lithology and sedimentary structure, eight lithofacies from electrical images, referred to as image lithofacies, is established for the fan-deltas. Granules to coarse-pebbles within massive beddings, granules to coarse-pebbles within cross and parallel beddings, siltstones within horizontal and massive beddings are the most developed lithofacies respectively in T1b1, T1b2 and T1b3. It indicates a gradual rise of the lake level of Mahu depression during the Early Triassic, with the fan-delta aprons retrograding towards to the margin of the basin. Therefore, the borehole electrical imaging log compensate for the limitation of cores of the Baikouquan Formation, providing an effective new approach to interpret the lithofacies of fan-delta.

Utilizing borehole electrical images to interpret lithofacies of fan-delta: A case study of Lower Triassic Baikouquan Formation in Mahu Depression, Junggar Basin, China

Science.gov (United States)

Yuan, Rui; Zhang, Changmin; Tang, Yong; Qu, Jianhua; Guo, Xudong; Sun, Yuqiu; Zhu, Rui; Zhou, Yuanquan (Nancy)

2017-11-01

Large-scale conglomerate fan-delta aprons were typical deposits on the slope of Mahu Depression during the Early Triassic. Without outcrops, it is difficult to study the lithofacies only by examining the limited cores from the main oil-bearing interval of the Baikouquan Formation. Borehole electrical imaging log provides abundant high-resolution geologic information that is obtainable only from real rocks previously. Referring to the lithology and sedimentary structure of cores, a case study of fan-deltas in the Lower Triassic Baikouquan Formation of the Mahu Depression presents a methodology for interpreting the complicated lithofacies utilizing borehole electrical images. Eleven types of lithologies and five types of sedimentary structures are summarized in borehole electrical images. The sediments are fining upward from gravel to silt and clay in the Baikouquan Formation. Fine-pebbles and granules are the main deposits in T1b1 and T1b2, but sandstones, siltstones and mudstones are more developed in T1b3. The main sedimentary textures are massive beddings, cross beddings and scour-and-fill structures. Parallel and horizontal beddings are more developed in T1b3 relatively. On integrated analysis of the lithology and sedimentary structure, eight lithofacies from electrical images, referred to as image lithofacies, is established for the fan-deltas. Granules to coarse-pebbles within massive beddings, granules to coarse-pebbles within cross and parallel beddings, siltstones within horizontal and massive beddings are the most developed lithofacies respectively in T1b1, T1b2 and T1b3. It indicates a gradual rise of the lake level of Mahu depression during the Early Triassic, with the fan-delta aprons retrograding towards to the margin of the basin. Therefore, the borehole electrical imaging log compensate for the limitation of cores of the Baikouquan Formation, providing an effective new approach to interpret the lithofacies of fan-delta.

The Petäjäskoski Formation, a new lithostratigraphic unit in the Paleoproterozoic Peräpohja Belt, northern Finland

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Markus Kyläkoski

2012-12-01

Full Text Available This paper gives the first description of a newly-recognized, basin-wide metasedimentary unit in the Paleoproterozoic (~2.4–1.9 Ga Peräpohja Belt, northern Finland. The unit, which is named the Petäjäskoski Formation (PFm after the single location where the rocks are known to be exposed, is situated stratigraphically in the middle part of the Kivalo Group between the quartzites of the>2.22 Ga Palokivalo Formation and the mafic volcanic rocks of the ~2.1 Ga Jouttiaapa Formation.The bulk of the PFm comprises phlogopitic-sericitic and albitic schists with abundant hematite as a diagnostic feature. Quartzite and dolomite interbeds are common. Based on drillcore and geophysical data, the succession is several hundreds of meters thick. The unit has prograde, chiefly lower greenschist facies mineral assemblages and, though being commonly intensely deformed, shows well-preserved sedimentary structures that imply deposition in shallow-water tosubaerial environments. Based on the original lithological features, the Petäjäskoski Formation can be defined as a claystone-siltstone-sandstone-dolostone association. On the geochemical and stratigraphic basis, the albite schists likely represent albitized equivalents of the micaceous claystones and siltstones. They are intercalated with stratabound collapse breccias, up to tens of meters in thickness, with clasts composed mainly of bordering albite schist. A mafic sill intruding the Petäjäskoski Formation yielded a U-Pb zircon age of 2140 ± 11 Ma. The older, c. 2220 Ma, differentiated sills are not known to reach the stratigraphic level of thePetäjäskoski Formation and hence, the depositional age of the PFm sediments can be bracketed between c. 2220 and 2140 Ma. Detrital zircon grains dated from a quartzitic sample from the PFmshow an Archean (c. 2650–3470 Ma provenance.The moderate to high MgO (~6–13 wt.%, K2O (~3–8 wt.% and FeOtot(8–15 wt.% contents, low CaO and Na2O contents, and abundant

The Shublik Formation and adjacent strata in northeastern Alaska description, minor elements, depositional environments and diagenesis

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Tourtelot, Harry Allison; Tailleur, Irvin L.

1971-01-01

The Shublik Formation (Middle and Late Triassic) is widespread in the surface and subsurface of northern Alaska. Four stratigraphic sections along about 70 miles of the front of the northeastern Brooks Range east of the Canning giver were examined and sampled in detail in 1968. These sections and six-step spectrographic and carbon analyses of the samples combined with other data to provide a preliminary local description of the highly organic unit and of the paleoenvironments. Thicknesses measured between the overlying Kingak Shale of Jurassic age and the underlying Sadlerochit Formation of Permian and Triassic age range from 400 to more than 800 feet but the 400 feet, obtained from the most completely exposed section, may be closer to the real thickness across the region. The sections consist of organic-rich, phosphatic, and fossiliferous muddy, silty, or carbonate rocks. The general sequence consists, from the bottom up, of a lower unit of phosphatic siltstone, a middle unit of phosphatic carbonate rocks, and an upper unit of shale and carbonate rocks near the Canning River and shale, carbonate rocks, and sandstone to the east. Although previously designated a basal member of the Kingak Shale (Jurassic), the upper unit is here included with the Shublik on the basis of its regional lithologic relation. The minor element compositions of the samples of the Shublik Formation are consistent with their carbonaceous and phosphatic natures in that relatively large amounts of copper, molybdenum, nickel, vanadium and rare earths are present. The predominantly sandy rocks of the underlying Sadlerochit Formation (Permian and Triassic) have low contents of most minor elements. The compositions of samples of Kingak Shale have a wide range not readily explicable by the nature of the rock: an efflorescent sulfate salt contains 1,500 ppm nickel and 1,500 ppm zinc and large amounts of other metals derived from weathering of pyrite and leaching of local shale. The only recorded

Subsurface-controlled geological maps for the Y-12 plant and adjacent areas of Bear Creek Valley

International Nuclear Information System (INIS)

King, H.L.; Haase, C.S.

1987-04-01

Bear Creek Valley in the vicinity of the US Department of Energy Y-12 Plant is underlain by Middle to Late Cambrian strata of the Conasauga Group. The group consists of interbedded limestones, shales, mudstones, and siltstones, and it can be divided into six discrete formations. Bear Creek Valley is bordered on the north by Pine Ridge, which is underlain by sandstones, siltstones, and shales of the Rome Formation, and on the south by Chestnut Ridge, which is underlain by dolostones of the Knox Group. Subsurface-controlled geological maps illustrating stratigraphic data and formational contacts for the formations within the Conasauga Group have been prepared for the Y-12 Plant vicinity and selected areas in Bear Creek Valley westward from the plant. The maps are consistent with all available surface and subsurface data for areas where sufficient data exist to make map construction feasible. 13 refs

Calcite Twinning in the Ordovician Martinsburg Formation, Delaware Water Gap, New Jersey, USA: Implications for Cleavage Formation and Tectonic Shortening in the Appalachian Piedmont Province

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John P. Craddock

2016-02-01

Full Text Available A traverse across the Stone Church syncline in the Ordovician Martinsburg turbidites reveals an axial planar cleavage (N40°E, SE dips in regional thrust-related folds (N40°E, shallow plunges and five phases of sparry calcite. Calcite fillings are bedding-parallel, cleavage-parallel, and one vein set cross-cuts both earlier phases; the youngest calcite filling is a bedding-parallel fault gouge that crosscuts the cleavage and preserves top-down-to-the-southeast normal fault kinematics. Calcite veins unique to disharmonically-folded calcareous siltstones (Maxwell, 1962 were also analyzed. Stable isotopic analysis (O, C of all of the calcite phases indicates a uniform fluid source (δ13C −2.0, δ18O −13.3 VPDB and, potentially, a similar precipitation and mechanical twinning age. The twinning strains (n = 1341; average Δσ = −32 MPa; average ε1 = −2.9% in the calcite suite are consistent with SE-NW thrust shortening, and sub-horizontal shortening perpendicular to evolving axial planar cleavage planes in the Stone Church syncline. Calcareous siltstone layers within the Martinsburg Fm. turbidites share concordant bedding planes and are unique, chemically (XRF, but folded and cleaved differently than the surrounding clay-rich Martinsburg turbidites. Neither sediment type yielded detrital zircons. Electron backscatter X-ray diffraction (EBSD and calcite twinning results in a folded calcareous siltstone layer preserving a layer-normal SE-NW shortening strain and Lattice Preferred Orientation (LPO. Shortening axes for the five-phase calcite suite trends ~N40°W, consistent with tectonic transport associated with crystalline nappe emplacement of the Reading Prong within the Piedmont province.

Mapping Bedrock Topography using Electromagnetic Profiling ...

African Journals Online (AJOL)

Mapping Bedrock Topography using Electromagnetic Profiling. ... will be constructed The area under study is within the Abakaliki Shales Geologic Formation. ... micaceous sandstone; micaceous siltstone, sandy shales and shelly limestone.

Geological mapping and analysis in determining resource recitivity limestone rocks in the village of Mersip and surrounding areas, district Limun, Sorolangun Regency, Jambi Province

Science.gov (United States)

Dona, Obie Mario; Ibrahim, Eddy; Susilo, Budhi Kuswan

2017-11-01

The research objective is to describe potential, to analyze the quality and quantity of limestone, and to know the limit distribution of rocks based on the value of resistivity, the pattern of distribution of rocks by drilling, the influence mineral growing on rock against resistivity values, the model deposition of limestone based on the value resistivity of rock and drilling, and the comparison between the interpretation resistivity values based on petrographic studies by drilling. Geologic Formations study area consists of assays consisting of altered sandstone, phyllite, slate, siltstone, grewake, and inset limestone. Local quartz sandstone, schist, genealogy, which is Member of Mersip Stylists Formation, consists of limestone that formed in shallow seas. Stylists Formation consists of slate, shale, siltstone and sandstone. This research methodology is quantitative using experimental observation by survey. This type of research methodology by its nature is descriptive analysis.

Applying of the Artificial Neural Networks (ANN) to Identify and Characterize Sweet Spots in Shale Gas Formations

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Puskarczyk, Edyta

2018-03-01

The main goal of the study was to enhance and improve information about the Ordovician and Silurian gas-saturated shale formations. Author focused on: firstly, identification of the shale gas formations, especially the sweet spots horizons, secondly, classification and thirdly, the accurate characterization of divisional intervals. Data set comprised of standard well logs from the selected well. Shale formations are represented mainly by claystones, siltstones, and mudstones. The formations are also partially rich in organic matter. During the calculations, information about lithology of stratigraphy weren't taken into account. In the analysis, selforganizing neural network - Kohonen Algorithm (ANN) was used for sweet spots identification. Different networks and different software were tested and the best network was used for application and interpretation. As a results of Kohonen networks, groups corresponding to the gas-bearing intervals were found. The analysis showed diversification between gas-bearing formations and surrounding beds. It is also shown that internal diversification in sweet spots is present. Kohonen algorithm was also used for geological interpretation of well log data and electrofacies prediction. Reliable characteristic into groups shows that Ja Mb and Sa Fm which are usually treated as potential sweet spots only partially have good reservoir conditions. It is concluded that ANN appears to be useful and quick tool for preliminary classification of members and sweet spots identification.

Soft-Sediment Deformation Structures Interpreted as Seismites in the Kolankaya Formation, Denizli Basin (SW Turkey)

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Topal, Savaş; Özkul, Mehmet

2014-01-01

The NW-trending Denizli basin of the SW Turkey is one of the neotectonic grabens in the Aegean extensional province. It is bounded by normal faults on both southern and northern margins. The basin is filled by Neogene and Quaternary terrestrial deposits. Late Miocene- Late Pliocene aged Kolankaya formation crops out along the NW trending Karakova uplift in the Denizli basin. It is a typical fluviolacustrine succession that thickens and coarsens upward, comprising poorly consolidated sand, gravelly sand, siltstone and marl. Various soft-sediment deformation structures occur in the formation, especially in fine- to medium grained sands, silts and marls: load structures, flame structures, clastic dikes (sand and gravely-sand dike), disturbed layers, laminated convolute beds, slumps and synsedimentary faulting. The deformation mechanism and driving force for the soft-sediment deformation are related essentially to gravitational instability, dewatering, liquefaction-liquidization, and brittle deformation. Field data and the wide lateral extent of the structures as well as regional geological data show that most of the deformation is related to seismicity and the structures are interpreted as seismites. The existence of seismites in the Kolankaya Formation is evidence for continuing tectonic activity in the study area during the Neogene and is consistent with the occurrence of the paleoearthquakes of magnitude >5. PMID:25152909

Depositional environments of the uranium bearing Cutler Formations, Lisbon Valley, Utah

International Nuclear Information System (INIS)

Campbell, J.A.; Steele-Mallory, B.A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67 0 W. on the average, whereas marine currents moved sediment S. 36 0 E. and N. 24 0 W., and wind transported sand S. 80 0 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little

Depositional environments of the uranium-bearing Cutler Formations, Lisbon Valley, Utah

Science.gov (United States)

Campbell, John A.; Steele-Mallory, Brenda A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67? W. on the the average, whereas marine currents moved sediment S. 36? E. and N. 24? W., and wind transported sand S. 800 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little.

Depositional environment of the Fort Member of the Jurasic Jaisalmer Formation (western Rajasthan, India), as revealed from lithofacies and grain-size analysis

International Nuclear Information System (INIS)

Ahmad, F.; Quasim, M.; Ghaznavi, A.; Khan, Z.; Ahmad, A.H.M.

2017-01-01

Lithofacies and granulometric analysis were carried out to decipher the depositional environment of the Fort Member of the Jurassic Jaisalmer Formation. Based on field data nine lithofacies have been identified including trough cross-bedded sandstones, planar cross-bedded sandstones, matrix supported conglomerates, thinly bedded siltstone and sandstones, herringbone cross-bedded sandstones, wave rippled sandstones, laminated sandstones, hummocky cross-bedded sandstones, limestones and shales. Granulometric analysis of the sandstones samples has been carried out for their statistical and textural parameters. Bivariant plots of textural parameters such as graphic skewness versus graphic standard deviation and kewness versus standard deviation confirm the high energy (beach) origin of sandstones. These results suggest a wide spectrum of marine environments ranging from inner shelf to upper shoreface for the Fort Member sandstones.

Preliminary environmental analysis of Gondwana in Candiota Region, Rio Grande do Sul

International Nuclear Information System (INIS)

Silveira Fontes, L.C. da; Cava, L.T.

1980-10-01

The geological results obtained in the Candiota Region by NUCLEBRAS, during the evaluation of the uranium economic potential from basal Gondwana Sequence - Itarare Group and Rio Bonito Formation - at South-East of the Parana Sedimentary Basin, are studied. The analysis of 18 geologic sections (scales 1:5.000 x 1:500), 21 drill holes and fotogeologic interpretation in the scale 1:50.000, are included. The Itarare Group sedimentation was conditioned by paleo - relief with valleys formed from differential erosion on 'horst - graben' structures. The deposition of its rhythmites, diamictites and siltstones was made in periglacial and marine environments. The sedimentation of the Rio Bonito Formation is related to the main Itarare Group depositional axes. The typical lithologies are: sandstones, siltstones, mudstones and coals, representing progradational fluvial sediments over coastal - plain areas. (Author) [pt

SOME INOZOID SPONGES FROM UPPER TRIASSIC (NORIAN-RHAETIAN NAYBAND FORMATION OF CENTRAL IRAN

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BABA SENOWBARI-DARYAN

1997-11-01

Full Text Available Some small-scaled Norian-Rhaetian reefs and reef mounds are imbedded within the shales, siltstones and siliciclastic-carbonate deposits of the Nayband Formation in central Iran. These deposits belong to the central Iranian plate as part of the Cimmerian Continent. Most of the biogenic rocks have a biostromal geometry, biohermal constructions are rare. Inozoid, sphinctozoid, and chaetetid sponges are, beside of corals and other reef builders, the most important reef organisms within these bioconstructions. In some reefs a variety of hexactinellid sponges also occur. The following inozoid sponges are described in this paper: Radiofibra norica n. sp., Permocorynella maxima n. sp., ?Sestrostomella robusta, Marawandia iranica, n. gen., n. sp. and Enaulofungia? triassica n. sp. The first four taxa are among the most abundant sponges within the Nayband Formation where it is exposed in several localities in central Iran. Enaulofungia? triassica, however, is not an abundant sponge there. These inozoid sponges have never been reported from the Triassic deposits of this region. Radiofibra, until now known only from the Upper Permian of Djebel Tebaga (Tunisia, is reported here for the first time from Triassic rocks. The stratigraphic as well as the paleogeographic distribution of all the genera are discussed.   

Depositional Architecture of Late Cambrian-Early Ordovician Siliciclastic Barik Formation; Al Huqf Area, Oman

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Abbasi, Iftikhar Ahmed

2017-04-01

Early Paleozoic siliciclastics sediments of the Haima Supergroup are subdivided into a number of formations and members based on lithological characteristics of various rock sequences. One of the distinct sandstone sequence, the Barik Formation (Late Cambrian-Early Ordovician) of the Andam Group is a major deep gas reservoir in central Oman. The sandstone bodies are prospective reservoir rocks while thick shale and clay interbeds act as effective seal. Part of the Barik Formation (lower and middle part) is exposed in isolated outcrops in Al Huqf area as interbedded multistoried sandstone, and green and red shale. The sandstone bodies are up to 2 meters thick and can be traced laterally for 300 m to over 1 km. Most of sandstone bodies show both lateral and vertical stacking. Two types of sandstone lithofacies are identified on the basis of field characteristics; a plane-bedded sandstone lithofacies capping thick red and green color shale beds, and a cross-bedded sandstone lithofacies overlying the plane-bedded sandstone defining coarsening upward sequences. The plane-bedded sandstone at places contains Cruziana ichnofacies and bivalve fragments indicating deposition by shoreface processes. Thick cross-bedded sandstone is interpreted to be deposited by the fluvial dominated deltaic processes. Load-casts, climbing ripples and flaser-bedding in siltstone and red shale indicate influence of tidal processes at times during the deposition of the formation. This paper summarizes results of a study carried out in Al Huqf area outcrops to analyze the characteristics of the sandstone-body geometry, internal architecture, provenance and diagenetic changes in the lower and middle part of the formation. The study shows build-up of a delta complex and its progradation over a broad, low-angle shelf where fluvial processes operate beside shoreface processes in a vegetation free setting. Keywords: Andam Group, Barik Formation, Ordovician sandstone, Al Huqf, Central Oman,

Aquifer Characterization and Groundwater Potential Evaluation in Sedimentary Rock Formation

Science.gov (United States)

Ashraf, M. A. M.; Yusoh, R.; Sazalil, M. A.; Abidin, M. H. Z.

2018-04-01

This study was conducted to characterize the aquifer and evaluate the ground water potential in the formation of sedimentary rocks. Electrical resistivity and drilling methods were used to develop subsurface soil profile for determining suitable location for tube well construction. The electrical resistivity method was used to infer the subsurface soil layer by use of three types of arrays, namely, the pole–dipole, Wenner, and Schlumberger arrays. The surveys were conducted using ABEM Terrameter LS System, and the results were analyzed using 2D resistivity inversion program (RES2DINV) software. The survey alignments were performed with maximum electrode spreads of 400 and 800 m by employing two different resistivity survey lines at the targeted zone. The images were presented in the form of 2D resistivity profiles to provide a clear view of the distribution of interbedded sandstone, siltstone, and shale as well as the potential groundwater zones. The potential groundwater zones identified from the resistivity results were confirmed using pumping, step drawdown, and recovery tests. The combination among the three arrays and the correlation between the well log and pumping test are reliable and successful in identifying potential favorable zones for obtaining groundwater in the study area.

Deposits of the Peruvian Pisco Formation compared to layered deposits on Mars

Science.gov (United States)

Sowe, M.; Bishop, J. L.; Gross, C.; Walter, S.

2013-09-01

Deposits of the Peruvian Pisco Formation are morphologically similar to the mounds of Juventae Chasma at the equatorial region on Mars (Fig. 1). By analyzing these deposits, we hope to gain information about the environmental conditions that prevailed during sediment deposition and erosion, hence conditions that might be applicable to the Martian layered and hydrated deposits. Mariner 9 data of the Martian mid-latitudes have already shown evidence of the wind-sculptured landforms that display the powerful prevailing eolian regime [1]. In addition, [2] reported on similarities between Martian erosional landforms and those of the rainless coastal desert of central Peru from the Paracas peninsula to the Rio Ica. As indicated by similar erosional patterns, hyper-arid conditions and unidirectional winds must have dominated at least after deposition of the sediments, which are intermixed volcaniclastic materials and evaporate minerals at both locations. Likewise, variations in composition are displayed by alternating layers of different competence. The Pisco formation bears yardangs on siltstones, sandstones and clays with volcaniclastic admixtures [3] whereas the presence of sulphate minerals and the omnipresent mafic mineralogy has been reported for the layered mounds of Juventae Chasma equally [4]. Likewise, a volcanic airfall deposition and lacustrine formation have been proposed for the sulphate-rich deposits of Juventae Chasma [5,6]. In order to find out about potential spectral similarities, we performed a detailed spectral analysis of the surface by using LANDSAT and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) VNIR/ SWIR data (visible to near-infrared and shortwave infrared region).

Weddellian marine/coastal vertebrates diversity from a basal horizon (Ypresian, Eocene of the Cucullaea I Allomember, La Meseta formation, Seymour (Marambio Island, Antarctica

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Marcelo A. Reguero

2013-06-01

Full Text Available The La Meseta Formation crops out in Seymour/Marambio Island, Weddell Sea, northeast of the Antarctic Peninsula and contains one of the world's most diverse assemblages of Weddellian marine/coastal verte-brates of Early Eocene (Ypresian age. The La Meseta Formation is composed of poorly consolidated, marine sandstones and siltstones which were deposited in a coastal, deltaic and/or estuarine environment. It includes marine invertebrates and vertebrates as well as terrestrial vertebrates and plants. The highly fossiliferous basal horizon (Cucullaeashell bed, Telm 4 of Sadler 1988 of the CucullaeaI Allomember is a laterally extensive shell bed with sandy matrix. The fish remains, including 35 species from 26 families, of the Ypresian Cucullaeabed represent one of the most abundant and diverse fossil vertebrate faunas yet recorded in southern latitudes. Stratigraphic distribution and phylogenetic relationships of the Weddellian sphenisciforms are consistent with a first radiation of this group in the Early Eocene. The first inquestionable archaeocete from Antarctica is recorded in this unit and is referred to a new taxon.

Tertiary lithofacies and paleo-geographic framework and interlayer oxidation zone sandstone uranium deposits in Longjiang-Zhaozhou area

International Nuclear Information System (INIS)

Zhang Zhenqiang

2003-01-01

The main points of views for the experiment are: (1) Yi'an formation is mainly composed of limnetic facies of siltstone and fine sandstone, due to weak surface water, limited sedimentation and simple material source; (2) strengthened surface water and enormous material brought from north and west-north and enlarged sedimentation from north to south, the major deposition during Da'an period are channel facies of conglomerate and river bed facies of sandstone; (3) stronger surface water during Taikang period, led alluvial-flood plain facies brown-yellow conglomerate to develop along western margin of the basin, the channel facies of conglomerate and river bed facies of grey-green sandstone, pelitic siltstone were widely formed southward and eastward; (4) according to the lithofacies criterion for in-situ leachable sandstone uranium ore, Taikang formation is an ideal horizon, river bed facies is suitable for interlayer oxidation type uranium deposit. (author)

Cathodoluminescence investigations on quartz cement in the sandstones of Khabour Formation from Iraqi Kurdistan Region, Northern Iraq

Science.gov (United States)

Omer, Muhamed F.; Friis, Henrik

2014-03-01

The Ordovician deltaic to shallow marine Khabour Formation in Northern Iraq consists mainly of sandstone with minor siltstone and interbedded shale. The sandstones are pervasively cemented by quartz that resulted in very little preserved primary porosity. Cathodoluminescence and petrographic studies showed that the silica cementation occurred in five successive phases which can be distinguished by their luminescence pattern. The precipitations of two phases have predated the major compaction process while the other phases are younger. The successive phases represent a sequence of changes in silica supply which were classified as very early and early, derived from dissolved biogenic silica that precipitated as opal/microquartz, possibly pre-compactional and of non-luminescent quartz overgrowth type. This was followed by phases whose silica supply derived from pressure solution of quartz, dissolution of feldspar, and hydrothermal fluids related to major thrust fault event. These successive quartz cement phases showed an increase in luminescence and the development of complicated zonation pattern in late-stage quartz cementation.

Leslie Cemetery and Francisco distributary fluvial channels in the Petersburg Formation (Pennsylvanian) of Gibson County, Indiana, USA

Energy Technology Data Exchange (ETDEWEB)

Eggert, D L

1984-01-01

The Leslie Cemetery Channel is a small distributary fluvial channel that is partly contemporaneous with the Springfield Coal member of the Petersburg Formation (Pennsylvanian) and splits the seam into two seams. This channel is 1-6 miles (1.6-10 km) wide and extends 30 miles (48 km) in the subsurface. Overbank and channel fill deposits consisting of sandstone, siltstone, and mudstone split the coal into two seams up to 40-50 ft (12-15 m) apart in places. The lower seam is a low-sulphur coal. Adjacent to this channel is the unsplit coal, which is as much as 9 ft (3 m) thick. Beneath the Leslie Cemetery Channel and the Springfield coal is the slightly older Francisco Channel (new name), which is younger than the next lower coal. This channel is filled with a fining-upward sandstone as much as 75 ft (23 m) thick. The positions of these stacked channels were determined by the differential compaction of earlier sediments. 20 references.

Sedimentology of SPICE (Steptoean positive carbon isotope excursion): A high-resolution trace fossil and microfabric analysis of the middle to late Cambrian Alum Shale Formation, southern Sweden

Science.gov (United States)

Egenhoff, Sven; Fishman, Neil; Ahlberg, Per; Maletz, Jorg; Jackson, Allison; Kolte, Ketki; Lowers, Heather; Mackie, James; Newby, Warren; Petrowsky, Matthew

2015-01-01

The Cambrian Alum Shale Formation in the Andrarum-3 core from Scania, southern Sweden, consists of black siliciclastic mudstone with minor carbonate intercalations. Four facies comprise three siliciclastic mudstones and one fine-grained carbonate. The facies reflect deposition along a transect from deep ramp to basin on a Cambrian shelf. The three mudstone facies contain abundant clay clasts and laterally variable siltstone laminae. Bed-load transport processes seem to have dominated deposition on this deep shelf. These sedimentary rocks record mainly event deposition, and only relatively few, thin laminae probably resulted from suspension settling. The Alum Shale Formation deep shelf did not show a bioturbation gradient, but fecal strings are common and Planolites burrows are rare in all mudstone facies. Evidence for biotic colonization indicates that this mudstone environment was not persistently anoxic, but rather was most likely intermittently dysoxic. The Alum Shale Formation in the Andrarum-3 core shows an overall decrease of grain size, preserved energy indicators, and carbonate content upsection interpreted to reflect a deepening upward. The succession can also be divided into four small-scale fining-upward cycles that represent deepening, and four overlying coarsening-upward cycles that represent upward shallowing.

Anatomy and dimensions of fluvial crevasse-splay deposits: Examples from the Cretaceous Castlegate Sandstone and Neslen Formation, Utah, U.S.A.

Science.gov (United States)

Burns, C. E.; Mountney, N. P.; Hodgson, D. M.; Colombera, L.

2017-04-01

Crevasse-splay deposits form a volumetrically significant component of many fluvial overbank successions (up to 90% in some successions).Yet the relationships between the morphological form of accumulated splay bodies and their internal facies composition remains poorly documented from ancient successions. This work quantifies lithofacies distributions and dimensions of exhumed crevasse-splay architectural elements in the Campanian Castlegate Sandstone and Neslen Formation, Mesaverde Group, Utah, USA, to develop a depositional model. Fluvial crevasse-splay bodies thin from 2.1 m (average) to 0.8 m (average) and fine from a coarsest recorded grain size of lower-fine sand to fine silt away from major trunk channel bodies. Internally, the preserved deposits of splays comprise laterally and vertically variable sandstone and siltstone facies associations: proximal parts are dominated by sharp and erosional-based sandstone-prone units, which may be structureless or may comprise primary current lineation on beds and erosional gutter casts; medial parts comprise sets of climbing-ripple strata and small scale deformed beds; distal parts comprise sets of lower-stage plane beds and complex styles of lateral grading into fine-grained floodbasin siltstones and coals. Lithofacies arrangements are used to establish the following: (i) recognition criteria for crevasse-splay elements; (ii) criteria for the differentiation between distal parts of crevasse-splay bodies and floodplain fines; and (iii) empirical relationships with which to establish the extent (ca. 500 m long by 1000 m wide) and overall semi-elliptical planform shape of crevasse-splay bodies. These relationships have been established by high-resolution stratigraphic correlation and palaeocurrent analysis to identify outcrop orientation with respect to splay orientation. This permits lateral changes in crevasse-splay facies architecture to be resolved. Facies models describing the sedimentology and architecture of

Depositional environment, sand provenance, and diagenesis of the Basal Salina Formation (lower Eocene), northwestern Peru

Science.gov (United States)

Marsaglia, K. M.; Carozzi, A. V.

The Basal Salina Formation is a lower Eocene transgressive sequence consisting of interbedded shales, siltstones, and conglomeratic sandstones. This formation occurs in the Talara basin of northwestern Peru and is one of a series of complexly faulted hydrocarbon-producing formations within this extensional forearc basin. These sediments were probably deposited in a fan-delta complex that developed along the ancestral Amotape Mountains during the early Eocene. Most of the sediment was derived from the low-grade metamorphic and plutonic rocks that comprise the Amotape Mountains, and their sedimentary cover. Detrital modes of these sandstones reflect the complex tectonic history of the area, rather than the overall forearc setting. Unlike most forearc sediments, these are highly quartzose, with only minor percentages of volcanic detritus. This sand is variably indurated and cemented by chlorite, quartz, calcite, and kaolinite. Clay-mineral matrix assemblages show gradational changes with depth, from primarily detrital kaolinite to diagenetic chlorite and mixed-layered illite/smectite. Basal Salina sandstones exhibit a paragenetic sequence that may be tied to early meteoric influx or late-stage influx of thermally driven brines associated with hydrocarbon migration. Much of the porosity is secondary, resulting from a first-stage dissolution of silicic constituents (volcanic lithic fragments, feldspar, and fibrous quartz) and a later dissolution of surrounding carbonate cement. Types of pores include skeletal grains, grain molds, elongate pores, and fracture porosity. Measured porosity values range up to 24% and coarser samples tend to be more porous. Permeability is enhanced by fractures and deterred by clay-mineral cements and alteration residues.

The crazy hollow formation (Eocene) of central Utah

Science.gov (United States)

Weiss, M.P.; Warner, K.N.

2001-01-01

The Late Eocene Crazy Hollow Formation is a fluviatile and lacustrine unit that was deposited locally in the southwest arm of Lake Uinta during and after the last stages of the lake the deposited the Green River Formation. Most exposures of the Crazy Hollow are located in Sanpete and Sevier Counties. The unit is characterized by a large variety of rock types, rapid facies changes within fairly short distances, and different lithofacies in the several areas where outcrops of the remnants of the formation are concentrated. Mudstone is dominant, volumetrically, but siltstone, shale, sandstone, conglomerate and several varieties of limestone are also present. The fine-grained rocks are mostly highly colored, especially in shades of yellow, orange and red. Sand grains, pebbles and small cobbles of well-rounded black chert are widespread, and "salt-and-pepper sandstone" is the conspicuous characteristic of the Crazy Hollow. The salt-and-pepper sandstone consists of grains of black chert, white chert, quartz and minor feldspar. The limestone beds and lenses are paludal and lacustrine in origin; some are fossiliferous, and contain the same fauna found in the Green River Formation. With trivial exceptions, the Crazy Hollow Formation lies on the upper, limestone member of the Green River Formation, and the beds of the two units are always accordant in attitude. The nature of the contact differs locally: at some sites there is gradation from the Green River to the Crazy Hollow; at others, rocks typical of the two units intertongue; elsewhere there is a disconformity between the two. A variety of bedrock units overlie the Crazy Hollow at different sites. In the southeasternmost districts it is overlain by the late Eocene formation of Aurora; in western Sevier County it is overlain by the Miocene-Pliocene Sevier River Formation; in northernmost Sanpete County it is overlain by the Oligocene volcanics of the Moroni Formation. At many sites bordering Sanpete and Sevier Valleys

Taphonomy of Early Triassic fish fossils of the Vega-Phroso Siltstone Member of the Sulphur Mountain Formation near Wapiti Lake, British Columbia, Canada

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Karen Anderson

2013-10-01

Full Text Available The taphonomy of fishes living in lacustrine environments has been extensively studied in both the laboratory and the fossil record; the taphonomy of marine fishes, however, is poorly known. Triassic marine fishes with heavy ganoid and cosmoid scales, which provided protection from rapid taphonomic loss, offer a means to examine marine fish taphonomy in the fossil record. Four genera of Early Triassic fishes (the ray-finned actinopterygians Albertonia, Bobasatrania, Boreosomus, and the lobe-finned coelacanth (sarcopterygian, Whiteia from the Wapiti Lake, British Columbia locality of the Lower Triassic Sulphur Mountain Formation were examined in order to gain a better understanding of the taphonomy of fish in marine environments, determine ambient environmental conditions in the region during the Early Triassic, and ascertain the habitat and mode of life of the fish. Results indicate that environmental conditions that contributed to the preservation of the fossil fishes of the current study included deposition in deep, quiet waters, which reduced the odds of disarticulation, colder waters under higher pressure, which slowed decay and limited postmortem floatation, and waters that were anoxic, which discouraged predators and scavengers. In addition, the thickness of the primitive ganoid and cosmoid scales of the fossil fishes also increased their preservation potential. Taphonomic, physiological and environmental indicators suggest that Whiteia, Albertonia, and possibly Bobasatrania lived in deep, cold waters near the oxygen minimum zone, while Boreosomus lived higher in the water column. While the anatomical and physiological characteristics of modern fishes will likely continue to inhibit marine taphonomy studies, examination of ancient fish, particularly those with ganoid or cosmoid scales, may provide future avenues of research to gain a better understanding of marine fish taphonomy and provide a powerful tool to examine ancient fish behavior

Multi-element neutron activation analysis and solution of classification problems using multidimensional statistics

International Nuclear Information System (INIS)

Vaganov, P.A.; Kol'tsov, A.A.; Kulikov, V.D.; Mejer, V.A.

1983-01-01

The multi-element instrumental neutron activation analysis of samples of mountain rocks (sandstones, aleurolites and shales of one of gold deposits) is performed. The spectra of irradiated samples are measured by Ge(Li) detector of the volume of 35 mm 3 . The content of 22 chemical elements is determined in each sample. The results of analysis serve as reliable basis for multi-dimensional statistic information processing, they constitute the basis for the generalized characteristics of rocks which brings about the solution of classification problem for rocks of different deposits

A new pterosaur tracksite from the Jurassic Summerville formation, near Ferron, Utah

Science.gov (United States)

Mickelson, Debra L.; Lockley, Martin G.; Bishop, John; Kirkland, James I.

2003-01-01

Pterosaur tracks (cf. Pteraichnus) from the Summerville Formation of the Ferron area of central Utah add to the growing record of Pteraichnus tracksites in the Late Jurassic Summerville Formation and time-equivalent, or near time-equivalent, deposits. The site is typical in revealing high pterosaur track densities, but low ichnodiversity suggesting congregations or “flocks” of many individuals. Footprint length varies from 2.0 to 7.0 cms. The ratio of well-preserved pes:manus tracks is about 1:3.4. This reflects a bias in favor of preservation of manus tracks due to the greater weight-bearing role of the front limbs, as noted in other pterosaur track assemblages. The sample also reveals a number of well-preserved trackways including one suggestive of pes-only progression that might be associated with take off or landing, and another that shows pronounced lengthening of stride indicating acceleration.One well-preserved medium-sized theropod trackway (Therangospodus) and other larger theropod track casts (cf. Megalosauripus) are associated with what otherwise appears to be a nearly monospecific pterosaur track assemblage. However, traces of a fifth pes digit suggest some tracks are of rhamphorynchoid rather than pterodactyloid origin, as usually inferred for Pteraichnus. The tracks occur at several horizons in a thin stratigraphic interval of ripple marked sandstones and siltstones. Overall the assemblage is similar to others found in the same time interval in the Western Interior from central and eastern Utah through central and southern Wyoming, Colorado, northeastern Arizona, and western Oklahoma. This vast “Pteraichnusichnofacies,” with associated saurischian tracks, remains the only ichnological evidence of pre-Cretaceous pterosaurs in North America and sheds important light on the vertebrate ecology of the Summerville Formation and contiguous deposits.

Edad de la formación vijes en el pozo v3a, oligoceno del piedemonte oriental de la cordillera occidental, departamento del valle del cauca, colombia

OpenAIRE

Dueñas, Hernando; Navarrete, Rosa Esther; Mojica, Jairo; Pardo, Mauricio; Camargo, Roger

2012-01-01

Outcrops of the Vijes Formation are restricted to the Vijes and Mulaló areas, which are located in the northwestern part of the Valle del Cauca Basin. Based on its micro-paleontological content (palynomorphs and forams) an Oligocene age has been assigned for this Marine Unit for long time considered as an Eocene to Miocene Formation. The Vijes Formation, has a thickness close to 180 m. It is made up of limestones, dirty sandstones and calcareous siltstones, that allow to sub-divide it in four...

Catahoula formation as a source of sedimentary uranium deposits in east Texas

International Nuclear Information System (INIS)

Ledger, E.B.; Tieh, T.T.

1983-01-01

Volcanic glass-rich mudstone and siltstone samples from the Oligocene/Miocene Catahoula formation of Jasper County, Texas, and coeval volcaniclastic rock samples from Trans-Pecos, Texas, have been compared as to U, Th, Zr, Ti, K, Rb, and Sr contents. Uranium is slightly greater in the distal ash (5.85 ppM U) compared to the Trans-Pecos samples (average 5.41 ppM U). Diagenetic and pedogenetic alteration of Catahoula volcanic glass releases uranium to solution and, under favorable conditions, this uranium may accumulate to form ore bodies. Uranium has been produced from such ore bodies in south Texas, but economic deposits are not known in east Texas. Significant differences between south and east Texas include: (1) a greater amount of volcanic debris delivered to south Texas, both as air-fall ash and stream-transported material, (2) delivery of only air-fill ash to east Texas, (3) the possibility of more petroleum-related reductants such as H 2 S in south Texas, and (4) pervasive glass alteration with subsequent uranium release in south Texas due to late calichification. These differences argue against economic deposits of the south Texas type being found in east Texas. If economic deposits occur they are likely to be far downdip making exploration difficult and expensive

Stratigraphy and structural setting of Upper Cretaceous Frontier Formation, western Centennial Mountains, southwestern Montana and southeastern Idaho

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Dyman, T.S.; Tysdal, R.G.; Perry, W.J.; Nichols, D.J.; Obradovich, J.D.

2008-01-01

Stratigraphic, sedimentologic, and palynologic data were used to correlate the Frontier Formation of the western Centennial Mountains with time-equivalent rocks in the Lima Peaks area and other nearby areas in southwestern Montana. The stratigraphic interval studied is in the middle and upper parts (but not uppermost) of the formation based on a comparison of sandstone petrography, palynologic age data, and our interpretation of the structure using a seismic line along the frontal zone of the Centennial Mountains and the adjacent Centennial Valley. The Frontier Formation is comprised of sandstone, siltstone, mudstone, limestone, and silty shale in fluvial and coastal depositional settings. A distinctive characteristic of these strata in the western Centennial Mountains is the absence of conglomerate and conglomeratic sandstone beds. Absence of conglomerate beds may be due to lateral facies changes associated with fluvial systems, a distal fining of grain size, and the absence of both uppermost and lower Frontier rocks in the study area. Palynostratigraphic data indicate a Coniacian age for the Frontier Formation in the western Centennial Mountains. These data are supported by a geochronologic age from the middle part of the Frontier at Lima Peaks indicating a possible late Coniacian-early Santonian age (86.25 ?? 0.38 Ma) for the middle Frontier there. The Frontier Formation in the western Centennial Mountains is comparable in age and thickness to part of the Frontier at Lima Peaks. These rocks represent one of the thickest known sequences of Frontier strata in the Rocky Mountain region. Deposition was from about 95 to 86 Ma (middle Cenomanian to at least early Santonian), during which time, shoreface sandstone of the Telegraph Creek Formation and marine shale of the Cody Shale were deposited to the east in the area now occupied by the Madison Range in southwestern Montana. Frontier strata in the western Centennial Mountains are structurally isolated from other

Stratigraphy and geologic age of the Neogene Shimajiri Group in Kumejima Island, Ryukyu Islands, southwestern Japan

International Nuclear Information System (INIS)

Nakamura, Yodai; Asahara, Yoshihiro; Ozawa, Tomowo; Kameo, Koji

1999-01-01

The Neogene Shimajiri Group is distributed sporadically in the Ryukyu islands. This study focuses on the Shimajiri Group in Kumejima Island, central Ryukyu, and clarifies its stratigraphy and geologic age on the basis of 1) lithostratigraphy, 2) calcareous nannofossil biostratigraphy, and 3) strontium isotope stratigraphy. The Shimajiri Group in Kumejima Island unconformably overlies the middle Miocene Aradake Formation, and is overlain by the Pleistocene Ryukyu Group. The group is divided into three formations, namely the Maja, the Aka and the Uegusukudake Formations in ascending order, and the first two are redefined in this paper based on the new geologic evidence. The Maja Formation consists mainly of fine-grained sandstone, sandy siltstone and alternating beds of them. The Aka Formation is mainly composed of cross-stratified sandstone, pumiceous sandstone and tuffaceous siltstone, and unconformably overlies the Maja Formation. The Uegusukudake Formation, conformably overlying the Aka Formation, consists of basaltic lava, tuff breccia and andesite. On the basis of calcareous nannofossil biostratigraphy, the Maja and Aka Formations can be assigned to Zone CN9 and Zone CN12b of Okada and Bukry (1980) respectively. Strontium isotope ages of the molluscan fossil specimens obtained from the Maja and Aka Formations revealed that the Maja Formation is assigned to the late Miocene (ca. 7.8-7.2 Ma) and the Aka Formation is assigned to the late Pliocene (ca. 3.2-3.1 Ma). These ages are concordant with the nannofossil biostratigraphy. The upper Miocene Maja Formation yields many molluscan fossils in which the characteristic species of the Kakegawa Fauna, such as Amussiopecten praesignis and Mimachlamys satoi are contained. The molluscan fauna of the Maja Formation is significant in understanding the origin of the Kakegawa Fauna, as the characteristic species of the Plio-Pleistocene Kakegawa Fauna already appeared in the Ryukyu Islands in the late Miocene. (author)

Prograding coastal facies associations in the Vryheid formation (Permian) at Effingham quarries near Durban, South Africa

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Tavener-Smith, R.

1982-05-01

This paper describes and interprets a flat-lying, sandstone—siltstone sequence 70 m thick in three disused quarries. The beds comprise the lowest part of the Vryheid Formation (middle Ecca) in the Durban vicinity. The sequence is conveniently divisible into two parts: the Lower Division constitutes a prograding beach barrier association, while the upper one represents a back barrier lagoonal complex. Fourteen sedimentary facies are described and interpreted to represent a range of depositional environments including open water shelf silts, sandy shoreface and littoral deposits, organic-rich muds and peats of lagoonal origin, a tidal inlet, washover fans and a fluvial channel sand. Among the conclusions reached are that the local middle Ecca coastline extended in a northwest to southeast direction and that progradation was towards the southwest; that the coastline was microtidal and that stormy conditions were common with prevalent palaeowinds from the northwest. The absence of invertebrate body fossils in these strata is attributed to penecontemporaneous solution of shelly remains. This is the first time that a coastal sequence has been identified on the southeast margin of the Main Karoo Basin of South Africa

The Lower Cretaceous Way Group of northern Chile: An alluvial fan-fan delta complex

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Flint, S.; Clemmey, H.; Turner, P.

1986-01-01

Alluvial fan sediments of the Lower Cretaceous Coloso Basin in northern Chile were deposited in a half-graben and derived from andesitic volcanics of a former island arc. Transport directions were towards the east, away from the present-day Peru-Chile trench. Grain flow, density modified grain flow and sheetflow processes were responsible for most of the sediment deposition with cohesive debris flows playing only a minor part. An early phase of conglomerate deposition (Coloso Formation) into a restricted basin records the transition from proximal fan facies with abundant grain flows and remobilized screes to mid-fan facies dominated by sheetflows. Stratiform copper mineralization near the top of the lower conglomerates is related to the unroofing of the Jurassic island arc. This mineralization comprises copper sulphide-cemented sands and gravels and formed by the reaction of mineralized detritus with diagenetic and hydrothermal solutions. A later phase of deposition (Lombriz Formation) includes sandstones, siltstones and conglomerates with a source area different from the Coloso Formation. This change in source may be related to strike-slip tectonics as the basin extended. The Lombriz conglomerates pass distally (eastwards) into red sandstones and purple siltstones with thin limestones deposited under marine conditions. This sequence is interpreted as a major fan delta complex. It passes conformably into marine carbonates of the Tableado Formation signifying the complete drowning of the basin in lower Cretaceous times.

Sr isotope evidence for a lacustrine origin for the upper Miocene to Pliocene Bouse Formation, lower Colorado River trough, and implications for timing of Colorado Plateau uplift

Science.gov (United States)

Spencer, J.E.; Patchett, P.J.

1997-01-01

The upper Miocene to Pliocene Bouse Formation in the lower Colorado River trough, which consists largely of siltstone with basal tufa and marl, has been interpreted as estuarine on the basis of paleontology. This interpretation requires abrupt marine inundation that has been linked to early rifting in the Gulf of California and Salton trough. New strontium isotope measurements reported here from carbonates and invertebrate shells in the Bouse Formation reveal no evidence of marine water, but are consistent with deposition in a lake or chain of lakes fed by the Colorado River. Furthermore, the absence of a southward decrease in 87Sr/86Sr within the Bouse Formation does not support the estuarine model in which low 87Sr/86Sr marine Sr would have dominated the mouth of the hypothetical Bouse estuary. Elevation of originally marine 87Sr/86Sr in the Bouse Formation to its present level, due to postdepositional interaction with ground water, is unlikely because Sr from secondary calcite above, below, and within the Bouse Formation is consistently less radiogenic, not more, than Bouse marl and shells. In contrast to Bouse Sr, strontium from mollusks in tidal-flat and delta-front paleoenvironments in the contemporaneous Imperial Formation in the Salton trough and from the subsurface south of Yuma was derived from sea water and confirms the dominance of marine strontium near or at the mouth of the late Miocene to early Pliocene Colorado River. Inferred post-early Pliocene uplift of the Bouse Formation from below sea level to modern elevations of up to 550 m has been used to support a late Cenozoic uplift age for the nearby Colorado Plateau. This constraint on uplift timing is eliminated if the Bouse Formation is lacustrine.

Preliminary study of the favorability for uranium in the Madera Limestone, and Cutler and Chinle Formations of the Sierra Nacimiento-Jemez Mountains area, New Mexico

International Nuclear Information System (INIS)

Vizcaino, H.P.; O'Neill, A.J.; Dotterer, F.E.

1978-01-01

Small, surficial, secondary uranium deposits are present in several formations in the Sierra Nacimiento-Jemez Mountains region, but none of significant size are known. Field surveys indicate that the deposits are laterally discontinuous and are, in most cases, associated with carbonaceous debris. Mineral contents of as much as 0.18 percent U 3 O 8 are recorded. There are 2 known deposits in the Pennsylvanian Madera Limestone, 18 in the Permian Cutler Formation, and 3 in the Triassic Chinle Formation. The Madera Limestone consists of a lower and an upper member. The lower member is predominantly a dense limestone and is lithologically unfavorable. The upper member, which consists of several arkosic units interbedded with cherty limestone, is not a favorable host rock because of its thin arkosic units, the paucity of carbonaceous debris, and its lithologically unfavorable limestone. The Cutler Formation consists mostly of interfingering siltstones and fine- to coarse-grained feldspathic and arkosic sandstones of fluvial origin. The sandstones are generally lenticular, average about 40 ft in thickness, and are favorable. Cutler equivalents south of lat 36 0 N. (Abo and Yeso Formations) were not included in this study. The Chinle Formation in the project area consists of five members. The Agua Zarca Member, medium-grained to conglomeratic sandstone with beds that average 30 ft in thickness, is the only unit in the Chinle considered favorable. The stratigraphic units under consideration have been eroded and deformed; beds dip steeply. Upturned and deeply dissected beds afford access to infiltrating waters; oxidation and flushing of pre-existing uranium deposits is therefore suspected. The uranium deposits in the Madera, Cutler, and Chinle are likely to be remnants, and the probability of locating any large deposits within the area is therefore low

Investigation on the upper Paleozoic Strata in Tang-e-Zakeen, and introducing Zakeen formation, Kuh-e Faraghan Zagros Basin, South Iran

International Nuclear Information System (INIS)

Ghavidel-Syooki, M.

1998-01-01

A thick clastic sequence is well-developed in Tang-e-Zakeen, Kuh-e-Faraghan, being situated approximately 80 Km north of Bandar Abbas. The sequence is 340 m. thick and mainly consists of sandstone, siltstone, shale and subordinate dolomitic beds. So far, this clastic sequence has been called Faraghan Formation. This rock unit lacks marine fauna and based on stratigraphic position, it was assigned to the Early Permian (Szabo and Kheradpir, 1978). Since then, a detailed palynological study has been carried out on the Faraghan Formation by the author. These studies resulted identification of numerous palynomorph taxa, including miospore and acritarch species. The known palynomorph taxa indicated that, a major part of Faraghan Formation belongs to the Devonian Period, while the rest is Early Permian. As a result, the National Iranian Stratigraphic Committee decided and agreed upon to divide the Faraghan Formation into two rock units, namely, the Zakeen Formation, embracing the Devonian strata, and Faraghan Formation for the Early Permian sequence in the Zagros Basin respectively. The Zakeen Formation derives from the Zakeen Village which is located in the southern flank of Kuh-e-Faraghan, about 80 km north of Bandar Abbas. The type section of Zakeen Formation attains a thickness of 285m. in Tang-e-Zakeen, Kuh-e-Faraghan, approximately 23 Km from the Zakeen village. It disconformably rests on the Sarchahan Formation, while it too, disconformably overlain by the Faraghan Formation. A total of 100 samples from the Zakeen Formation were selected and treated in the palynological laboratory of the Exploration Division of National Iranian Oil Company. 63 palynomorph taxa were encountered from the Zakeen Formation. The known species were arranged in five local stratigraphic assemblage zones. Zones I and II occur in a thickness of 96 m. of the Zakeen Formation, in ascending order, suggesting the Early Devonian whereas Zones III and IV occur Within 156 m. interval of the Zakeen

Marine Jurassic lithostratigraphy of Thailand

Science.gov (United States)

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

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

PECULIAR FEATURES PERTAINING TO SOIL DEPOSIT FORMATION IN THE MESOPOTAMIA ZONE OF IRAQ

Directory of Open Access Journals (Sweden)

A. Al-Robai Ali

2013-01-01

Full Text Available The paper considers geological conditions for sedimentary mantle formation. In the geological past limestone deposits and sedimentation rock mass from fragmentary materials brought by water flows were formed in the southern part of the stretched geosyncline which had been submerged by shallow sea. By lapse of time deposits were transferred into sandstone, siltstone and mudstone that represented the bottom part of rock mass. Continental conditions were established as a result of orogenic process which took place nearly 30–50 million years ago. Erosional activity of wind and flowing waters was observed on the surface for a long period of time.The top part of soil rock mass is represented by alluvial deposits of the rivers Tigris and Euphrates. During the process of sediment deposition more full-flowing Tigris caused more complicated dynamics of water channels  including meandering and changeability of inter-bedding.Engineering and geological investigations have been carried out with the purpose to study structure of soil rock mass in various regions of the country (Al-Diwaniya, Khidr, Al-Nasiriya and Khila. Specific drill columns have been selected on the basis of analysis of soil rock masses.  Theses drill columns may serve for further selection of rational types of foundations (shallow foundation, piles foundation or creation of artificial foundations (cementing, armoring etc.. 

Provenance and tectonic setting of the Neoproterozoic clastic rocks hosting the Banana Zone Cu-Ag mineralisation, northwest Botswana

Science.gov (United States)

Kelepile, Tebogo; Bineli Betsi, Thierry; Franchi, Fulvio; Shemang, Elisha; Suh, Cheo Emmanuel

2017-05-01

Petrographic and geochemical data were combined in order to decipher the petrogenesis of the Neoproterozoic sedimentary succession associated with the Banana Zone Cu-Ag mineralisation (northwest Botswana), in the Kalahari Copperbelt. The investigated Neoproterozoic sedimentary succession is composed of two formations including the Ngwako Pan and the D'kar Formations. The Ngwako Pan Formation is made up of continental siliciclastic sediments, mainly sandstones interbedded with siltstones and mudstones, whereas the D'kar Formation is comprised of shallow marine laminated siltstones, sandstones and mudstones, with subordinate limestone. Copper-Ag mineralisation is essentially confined at the base of the D'kar Formation, which bears reduced organic components, likely to have controlled Cu-Ag precipitation. Sandstones of both the Ngwako Pan and the D'kar Formations are arkoses and subarkoses, composed of quartz (Q), feldspars (F) and lithic fragments (L). Moreover, geochemically the sandstones are considered as potassic and classified as arkoses. On the other hand, mudrocks of the D'kar Formation are finely laminated and are dominated by muscovite, sericite, chlorite and quartz. The modified chemical index of weathering (CIW‧) values indicated an intense chemical weathering of the source rock. The dominance of detrital quartz and feldspar grains coupled with Al2O3/TiO2 ratios (average 29.67 and 24.52 for Ngwako Pan and D'kar Formations, respectively) and Ni and Cr depletion in the sandstones, suggest a dominant felsic source. However, high concentrations of Ni and Cr and a low Al2O3/TiO2 ratio (block and deposited in a continental rift setting (passive margin) in a humid environment. The source rocks might have been the Palaeoproterozoic basement rocks (granitoids and granitic gneiss) and the Mesoproterozoic Kgwebe volcanic rocks exposed north of the study area.

Precambrian cyclic rhythmites: solar-climatic or tidal signatures?

International Nuclear Information System (INIS)

Williams, G.E.

1990-01-01

For more than 60 years geologists have sought evidence of solar-climatic cyclicity in rhythmically laminated sedimentary rocks, but claims in general have not been persuasive. Three Precambrian rhythmite sequences in Australia that comprise varve-like laminae recently have received attention, however, as their conspicuous cycles of ca. 10-14 and/or 20-25 laminae have been ascribed a sunspot-cycle origin. They are the 2500 Ma old Weeli Wolli Formation, the 1750 Ma old Wollogorang Formation and the 650 Ma old Elatina Formation. New observations for the Weeli Wolli Formation, a siliceous banded iron-formation, suggest a cycle period exceeding the 23 microband couplets proposed by Trendall, casting doubt on the solar interpretation. The Weeli Wolli cyclicity may record Earth-tidal rhythms that modulated the discharge and composition of silica- and iron-bearing fumarolic waters. The structure of the cycles of silty dolomite and mudstone in the Wollogorang Formation does not support a sunspot-cycle origin, and a tidal control on sedimentation should be considered. The Elatina sequence of cyclic sandstone and siltstone laminae displays several empirical similarities to the sunspot series. The discovery of thicker, more complex lamina-cycles in the correlative Reynella Siltstone has, however, caused reappraisal of the solar interpretation of the Elatina rhythmites. The Elatina series may encode unique information on lunar orbital periods and the Earth's palaeorotation: the data indicate ca. 30.5 days per lunar month, 13.1 lunar months and ca. 400 days per year, and lunar apsides and lunar nodal cycles of 9.7 and ca. 19.5 years respectively some 650 Ma ago. (author)

Fractured-aquifer hydrogeology from geophysical logs; the passaic formation, New Jersey

Science.gov (United States)

Morin, R.H.; Carleton, G.B.; Poirier, S.

1997-01-01

The Passaic Formation consists of gradational sequences of mudstone, siltstone, and sandstone, and is a principal aquifer in central New Jersey. Ground-water flow is primarily controlled by fractures interspersed throughout these sedimentary rocks and characterizing these fractures in terms of type, orientation, spatial distribution, frequency, and transmissivity is fundamental towards understanding local fluid-transport processes. To obtain this information, a comprehensive suite of geophysical logs was collected in 10 wells roughly 46 m in depth and located within a .05 km2 area in Hopewell Township, New Jersey. A seemingly complex, heterogeneous network of fractures identified with an acoustic televiewer was statistically reduced to two principal subsets corresponding to two distinct fracture types: (1) bedding-plane partings and (2) high-angle fractures. Bedding-plane partings are the most numerous and have an average strike of N84??W and dip of 20??N. The high-angle fractures are oriented subparallel to these features, with an average strike of N79??E and dip of 71??S, making the two fracture types roughly orthogonal. Their intersections form linear features that also retain this approximately east-west strike. Inspection of fluid temperature and conductance logs in conjunction with flowmeter measurements obtained during pumping allows the transmissive fractures to be distinguished from the general fracture population. These results show that, within the resolution capabilities of the logging tools, approximately 51 (or 18 percent) of the 280 total fractures are water producing. The bedding-plane partings exhibit transmissivities that average roughly 5 m2/day and that generally diminish in magnitude and frequency with depth. The high-angle fractures have average transmissivities that are about half those of the bedding-plane partings and show no apparent dependence upon depth. The geophysical logging results allow us to infer a distinct hydrogeologic structure

Demonstration of a Fractured Rock Geophysical Toolbox (FRGT) for Characterization and Monitoring of DNAPL Biodegradation in Fractured Rock Aquifers

Science.gov (United States)

2015-09-29

is characterized by dark gray slate or phyllite, alternating with thin layers of light gray siltstone or sandstone . Table 1 summarizes the primary...sedimentary rocks of the Newark Basin. Competent rocks are primarily mudstones and sandstones of the Lockatong and Stockton Formations. Fill, weathered silt... sandstone , and characterized by water bearing bedding plane fractures. An array of open boreholes in the source area that were drilled for the 2002

In-situ Substrate Addition to Create Reactive Zones for Treatment of Chlorinated Aliphatic Hydrocarbons: Vandenberg Air Force Base

Science.gov (United States)

2004-12-17

the diatomite and diatomaceous siltstone of the Sisquoc formation. This aquifer configuration affords an effective bottom to the unconfined aquifer and...dissolved phase (Suthersan 2002). Given the low TOC of the soils , this effect would be expected to be slight. The rise was approximately concurrent with... effects of molasses are not largely a “ soil washing” effect ? A mass balance approach seems essential. Please discuss this general concern, and

Stratigraphy and structure of the Miners Mountain area, Wayne County, Utah

Science.gov (United States)

Luedke, Robert G.

1953-01-01

The Miners Mountain area includes about 85 square miles in Wayne County, south-central Utah. The area is semiarid and characterized by cliffs and deep canyons. Formations range in age from Permian to Upper Jurassic and have an aggregate thickness of about 3,500 feet. Permian formations are the buff Coconino sandstone and the overlying white, limy, shert-containing Kaibab limestone. Unconformably overlying the Kaihab is the lower Triassic Moenkopi formation of reddish-brown and yellow mudstone, siltstone, and sandstone; it contains the Sinbad limestone member (?) in the lower part. Thin, lenticular Shinarump conglomerate unconformably overlies the Moenkopi, but grades upward into the Upper Triassic Chinle formation of variegated mudstone with some interbedded sandstone and limestone lenses. Uncomformably overlying the Chinle are the Wingate sandstone, Kayenta formation, and Navajo sandstone of the Jurassic (?) Glen Canyon group, which consist of red to white sandstone. Only the lower part of the Carmel formation of the Upper Jurassic San Rafael group is exposed in the area; it consists of variegated siltstone, sandstone, limestone, and gypsum. The conspicuous structural feature in the area is the Teasdale anticline which trends northwest, is about 14 miles long, and is asymmetric with a steeper west flank. Bounding the anticline on the northeast and east is the Capitol Reef monocline, the northern part of the Waterpocket Fold. Strata in the area are broken by steeply-dipping normal faults with small displacements, except for the Teasdale fault which has a maximum displacement of over 1,000 feet. Jointing is prominent in some formations. The major orogenic movement in the area is believed to be late Upper Cretaceous to early Tertiary. Epeirogenic uplift occurred intermittently throughout Tertiary and perhaps Quaternary time.

Preliminary stratigraphy and facies analysis of the Upper Cretaceous Kaguyak Formation, including a brief summary of newly discovered oil stain, upper Alaska Peninsula

Science.gov (United States)

Wartes, Marwan A.; Decker, Paul L.; Stanley, Richard G.; Herriott, Trystan M.; Helmold, Kenneth P.; Gillis, Robert J.

2013-01-01

The Alaska Division of Geological and Geophysical Surveys has an ongoing program aimed at evaluating the Mesozoic forearc stratigraphy, structure, and petroleum systems of lower Cook Inlet. Most of our field studies have focused on the Jurassic component of the petroleum system (this report). However, in late July and early August of 2012, we initiated a study of the stratigraphy and reservoir potential of the Upper Cretaceous Kaguyak Formation. The Kaguyak Formation is locally well exposed on the upper Alaska Peninsula (fig. 25) and was named by Keller and Reiser (1959) for a sequence of interbedded siltstone and sandstone of upper Campanian to Maastrichtian age that they estimated to be 1,450 m thick.Subsequent work by Detterman and Miller (1985) examined 900 m of section and interpreted the unit as the record of a prograding submarine fan.This interpretation of deep-water deposition contrasts with other Upper Cretaceous rocks exposed along the Alaska Peninsula and lower Cook Inlet that are generally described as nonmarine to shallow marine (Detterman and others, 1996; LePain and others, 2012).Based on foraminifera and palynomorphs from the COST No. 1 well, Magoon (1986) concluded that the Upper Cretaceous rocks were deposited in a variety of water depths and environments ranging from upper bathyal to nonmarine. During our recent fieldwork west and south of Fourpeaked Mountain, we similarly encountered markedly varying lithofacies in the Kaguyak Formation (fig. 25), and we also found oil-stained rocks that are consistent with the existence of an active petroleum system in Upper Cretaceous rocks on the upper Alaska Peninsula and in lower Cook Inlet. These field observations are summarized below.

Oligocene Fluvio-Deltaic Depositional Environments Salin Sub-Basin, Central Myanmar

Science.gov (United States)

Gough, A.; Hall, R.

2017-12-01

A recent increase in accessibility for research in Myanmar has allowed rapid advancements in the understanding of the geology of the country. Evolving depositional environments can be reconstructed in largely unstudied Oligocene deposits of the Salin sub-basin, of the Central Myanmar Basin. Data has been collected through a fieldwork campaign to target well-exposed sediments along the western margin of the basin. The studied outcrops span approximately one hundred kilometres from north to south, and a series of sedimentary logs, palaeocurrent data, 2D panel diagrams, and samples for petrographical analysis have been collected and interpreted. The Oligocene formations studied include the Shwezetaw, Paduang, and Okhmintaung, each of which show a broadly southwards-trending fluvio-deltaic environment of deposition. Towards the north, the lower Rupelian Shwezetaw Formation comprises thick fluviatile sandstones which grade southwards through macrotidal-dominated fluvio-deltaic interbedded siltstones and rare sandstones, into marine sandstones. Overlying this, the upper Rupelian Paduang Formation grades rapidly from rare fluvial sandstones towards the north of the basin into deltaic and marine interbedded sandstones and siltstones to the south. This formation is more marine in nature, suggesting a minor transgression throughout the lower Oligocene. By the time of deposition of the Okhmintaung Formation in the Chattian the observed deposits solely represent a tidally-influenced deltaic depositional environment, with very little temporal variation, suggesting a stable sea level. Despite the relatively unchanging depositional environment, the formations are approximately 4000 m thick, suggesting that sedimentation kept pace with relatively rapid subsidence. This current study, which will combine depositional environment reconstruction, provenance, and sediment routing analysis, will provide important insights into both the tectonic setting and the huge sediment accumulation

Paleomagnetic results of Neogene strata in Eastern Vietnam and their paleogeographic Implications

Science.gov (United States)

Weiwei, C.; Zhao, X.; Liu, Z.; Dong Pha, P.

2017-12-01

Neogene paleomagnetic data from the Vietnam, southeastern margin of the Indochina Block, are essential to reconstruct post-collisional paleogeography. This is key to understanding the evolution of the western South China Sea and verifying the model of extrusion tectonic. Mid-Miocene siltstone of the Song Ba Formation and Pliocene basalt were sampled from Phu Tue area, eastern Vietnam. Paleomagnetic samples were collected using a gasoline-powered drill and a magnetic compass mounted on an orienting device. We corrected for the effect of local magnetic anomalies on magnetic orientation by taking solar azimuths using a sun compass. For most samples, the discrepancy between the two compass readings is within 3°. Remanent magnetization measurements were carried out with 2G-755-4K cryogenic magnetometers, installed in the Plaleomagnetism Laboratory, Tongji University, Shanghai. All the instruments are located in a shielded room with residual fields less than 200 nT. The anisotropy of magnetic susceptibility (AMS) results of four siltstone sites (sites 2, 6, 9, 10) indicate the siltstone preserve a normal sedimentary magnetic fabric. The other sites of the AMS (including basalt sites) show that the directions of K1, K2, K3 are scattered without any regulation. The thermal demagnetization and AF demagnetization were performed on specimens and stepwise demagnetization up to 600°C or 150 mT. ChRM directions were determined for all the specimens using principal component analysis. The directions obtained from Neogene rocks are far from the present geomagnetic field (PGF) and include antipodal dual polarities, suggesting a primary origin. A visible fluctuation in paleomagnetic direction from one site to another is evident from the results. Shallow inclination are obtained from most samples which range of 7.4° to 21.5°. The siltstone declination range of 16.8° to 34.5° while the basalt declination rang of 178.3° to 335.0°. This wide range of direction fluctuation

Geochemical characteristics of crude oil from a tight oil reservoir in the Lucaogou Formation, Jimusar Sag, Junggar Basin

Science.gov (United States)

Cao, Z.

2015-12-01

Jimusar Sag, which lies in the Junggar Basin,is one of the most typical tight oil study areas in China. However, the properties and origin of the crude oil and the geochemical characteristics of the tight oil from the Lucaogou Formation have not yet been studied. In the present study, 23 crude oilsfrom the Lucaogou Formation were collected for analysis, such as physical properties, bulk composition, saturated hydrocarbon gas chromatography-mass spectrometry (GC-MS), and the calculation of various biomarker parameters. In addition,source rock evaluation and porosity permeability analysis were applied to the mudstones and siltstones. Biomarkers of suitable source rocks (TOC>1, S1+S2>6mg/g, 0.7%formation of crude oil in the lower section when compared with the upper section of the Lucaogou Formation. Oil-source correlations demonstrated that not all mudstones within the Lucaogou Formation contributed to oil accumulation.Crude oil from the upper and lower sections originated from thin-bedded mudstones interbedded within sweet spot sand bodies. A good coincidence of filling history and hydrocarbon generation history indicated that the Lucaogou reservoir is a typical in situ reservoir. The mudstones over or beneath the sweet spot bodies consisted of natural caprocks and prevented the vertical movement of oil by capillary forces. Despite being thicker, the thick-bedded mudstone between the upper and lower sweet spots had no obvious contribution to

Sedimentary paleoenvironments of the Candeleros Formation(Rio Limay Subgroup)upper cretaceous, Ezequiel Ramos Mexia, Neuquen, Argentina daming west, Argentina

International Nuclear Information System (INIS)

Sanchez, M.

2004-01-01

Sedimentary facies from the Candeleros Formation (Rio Limay Subgroup), cropping out at the El Escondido creek, at the Ezequiel Ramos Mexia dam, are analyzed and interpreted in this paper. A sedimentological detailed section was measured to get the main goal of this paper which is the sedimentary paleoenvironment. The outcroppings were pictured and a section was measured, geometries and espacial relation between them were analyzed. Eight lithofacies were identified which are: coarse sandstone facies (Se), sandstones (Sm, St, Sp, Sh t Sr), siltstones and shales (Fl and Fr). These lithofacies were agrupated into eight facies associations (FA). AFA constitutes the registration of multiepisodic events of sheet floods; AFB, C and D are product of the depositation in a braided channel belt, AFE represents units of lateral accretion, AFF is assigned deposits of crevasse splay and AFG and H are assigned to plain of flood. The distribution of these associations in the column defines an terminal fan paleoenvironment where is represented of base to top: distal (AFA, B and G) and proximal area (AFD and G) of the distributary plain; zone of feeding of the system (AFC, And, F and G), media-proximal distributary plain (AFD and F), proximal distributary plain (AFC, And, F and G); and flood basin (AFF, G and H) [es

Shallow marine event sedimentation in a volcanic arc-related setting: The Ordovician Suri Formation, Famatina range, northwest Argentina

Science.gov (United States)

Mangano, M.G.; Buatois, L.A.

1996-01-01

The Loma del Kilome??tro Member of the Lower Ordovician Suri Formation records arc-related shelf sedimentation in the Famatina Basin of northwest Argentina. Nine facies, grouped into three facies assemblages, are recognized. Facies assemblage 1 [massive and parallel-laminated mudstones (facies A) locally punctuated by normally graded or parallel-laminated silty sandstones (facies B] records deposition from suspension fall-out and episodic storm-induced turbidity currents in an outer shelf setting. Facies assemblage 2 [massive and parallel-laminated mudstones (facies A) interbedded with rippled-top very fine-grained sandstones (facies D)] is interpreted as the product of background sedimentation alternating with distal storm events in a middle shelf environment. Facies assemblage 3 [normally graded coarse to fine-grained sandstones (facies C); parallel-laminated to low angle cross-stratified sandstones (facies E); hummocky cross-stratified sandstones and siltstones (facies F); interstratified fine-grained sandstones and mudstones (facies G); massive muddy siltstones and sandstones (facies H); tuffaceous sandstones (facies I); and interbedded thin units of massive and parallel-laminated mudstones (facies A)] is thought to represent volcaniclastic mass flow and storm deposition coupled with subordinated suspension fall-out in an inner-shelf to lower-shoreface setting. The Loma del Kilo??metro Member records regressive-transgressive sedimentation in a storm- and mass flow-dominated high-gradient shelf. Volcano-tectonic activity was the important control on shelf morphology, while relative sea-level change influenced sedimentation. The lower part of the succession is attributed to mud blanketing during high stand and volcanic quiescence. Progradation of the inner shelf to lower shoreface facies assemblage in the middle part represents an abrupt basinward shoreline migration. An erosive-based, non-volcaniclastic, turbidite unit at the base of this package suggests a sea

Radioactivity of rocks from the geological formations belonging to the Tibagi River hydrographic basin

International Nuclear Information System (INIS)

Bastos, Rodrigo Oliveira

2008-01-01

This work is a study of the 40 K and the 238 U and 232 Th series radioactivity in rocks measured with high resolution gamma ray spectrometry. The rocks were taken from the geologic formations in the region of the Tibagi river hydrographic basin. The course of this river cuts through the Paleozoic and Mesozoic stratigraphic sequences of the Parana sedimentary basin. In order to take into account the background radiation attenuation by the samples, a technique was developed that eliminated the need to measure a blank sample. The effects of the radiation's self-attenuation in the sample matrix were taken into account by using a gamma ray direct transmission method. The results for 87 rock samples, taken from 14 distinct formations, and their corresponding radioactivity variations are presented and discussed according to the possible geological processes from which they originated. Among the most discussed results are: an outcrop that profiles shale, limestone and rhythmite in the Irati Formation; a sandstone and siltstone sequence from the Rio do Rasto Formation; and a profile sampled in a coal mine located in the Rio Bonito Formation. The calculations of the rocks' contributions to the outdoor gamma radiation dose rate agree with the values presented by other authors for similar rocks. The highest dose values were obtained from felsic rocks (rhyolite of the Castro group, 129.8 ± 3.7 nGy.h -1 , and Cunhaporanga granite, 167 ± 37 nGy.h -1 ). The other highest values correspond to the shale rocks from the Irati Formation (109 ± 16 nGy.h -1 ) and the siltic shale rocks from the Ponta Grossa Formation (107.9 ± 0.7 nGy.h -1 ). The most recent geological formations presented the lowest dose values (e.g. the Botucatu sandstone, 3.3 ± 0.6 nGy.h -1 ). The average value for sedimentary rocks from seven other formations is equal to 59 ± 26 nGy.h -1 . The Rio Bonito Formation presented the highest dose value (334 ± 193 nGy.h -1 ) mainly due to the anomalous 226 Ra

Cyclostratigraphic constraints on the duration of the Datangpo Formation and the onset age of the Nantuo (Marinoan) glaciation in South China

Science.gov (United States)

Bao, Xiujuan; Zhang, Shihong; Jiang, Ganqing; Wu, Huaichun; Li, Haiyan; Wang, Xinqiang; An, Zhengze; Yang, Tianshui

2018-02-01

Constructing an accurate timeline is critical for reconstructing the Earth systems through critical transitions in climate, geochemistry, and life. Existing dates constrain synchronous initiation (ca. 717 Ma) and termination (ca. 660 Ma) of the Sturtian glaciation from multiple continents. The termination of the younger Marinoan glaciation is also well dated at ca. 635 Ma, but the onset of this glaciation is only roughly constrained as ≤ ca. 654 Ma (South China) and ≥ ca. 639 Ma (Namibia). To test if the Marinoan glaciation started close to ca. 654 Ma or ca. 639 Ma, we have conducted a cyclostratigraphic study on the Cryogenian non-glacial Datangpo Formation that conformably overlies and underlies Sturtian and Marinoan glacial diamictites, respectively, in a deep-water basin section in South China. A total of 28,765 magnetic susceptibility (MS) measurements from a drillcore of the 292-m-thick, muddy siltstone- and shale-dominated Datangpo Formation are used for cyclostratigraphic analysis. The results reveal significant decameter- to meter-scale sedimentary cycles of 16-12 m, 3.6-3.0 m, 1.0-0.8 m, and 0.6-0.4 m. The ratios of these cycle wavelengths match well with those of the Milankovitch cycles calibrated for the Cryogenian Period. The established astrochronologic time scale suggests that the duration of the Datangpo Formation is about 9.8 million years. Together with the radiometric age of ca. 660 Ma for the termination of the Sturtian glaciation, the cyclostratigraphic data suggest that the Nantuo (Marinoan) glaciation in South China initiated at ca. 650 Ma, which is slightly younger than but consistent with the ca. 654 Ma U-Pb age from the top of the Datangpo Formation in shelf sections. This age, however, is significantly older than the ages obtained from Marinoan-age glacial diamictites in South China (ca. 636 Ma) and Namibia (ca. 639 Ma). Given that most of the shelf sections may have suffered from glacial erosion, obtaining the onset age of the

MESOZOIC BASALTIC MAGMATISM OF THE SIDI SAID MAACHOU BASIN (WESTERN MESETA, MOROCCO): PETROGRAPHY, GEOCHEMISTRY AND GEODYNAMIC IMPLICATIONS.

OpenAIRE

Abdelkbir Hminna; Hafid Saber; Abdelouahed Lagnaoui.

2017-01-01

The late Triassic-early Jurassic volcanism of Sidi Sa?d Maachou basin belongs to the costalMeseta and the Central Atlantic Magmatic Province (CAMP). The volcanic pile conformably overlies the red siltstones of Machraa Boujamaa Formation. This set includes a stack of several lava flows 40 to 80 m thick. The petrographic study shows that the textures vary from porphyritic to microlitic porphyritic. These igneous rocks have the geochemical characteristics of an intra-continental tholeiitic serie...

Stratigraphy, age, and depositional setting of the Miocene Barstow Formation at Harvard Hill, central Mojave Desert, California

Science.gov (United States)

Leslie, Shannon R.; Miller, David M.; Wooden, Joseph L.; Vazquez, Jorge A.

2010-01-01

New detailed geologic mapping and geochronology of the Barstow Formation at Harvard Hill, 30 km east of Barstow, CA, help to constrain Miocene paleogeography and tectonics of the central Mojave Desert. A northern strand of the Quaternary ENE-striking, sinistral Manix fault divides the Barstow Formation at Harvard Hill into two distinct lithologic assemblages. Strata north of the fault consist of: a green rhyolitic tuff, informally named the Shamrock tuff; lacustrine sandstone; partially silicified thin-bedded to massive limestone; and alluvial sandstone to pebble conglomerate. Strata south of the fault consist of: lacustrine siltstone and sandstone; a rhyolitic tuff dated at 19.1 Ma (U-Pb); rock-avalanche breccia deposits; partially silicified well-bedded to massive limestone; and alluvial sandstone and conglomerate. Our U-Pb zircon dating of the Shamrock tuff by SHRIMP-RG yields a peak probability age of 18.7 ± 0.1 Ma. Distinctive outcrop characteristics, mineralogy, remanent magnetization, and zircon geochemistry (Th/U) suggest that the Shamrock tuff represents a lacustrine facies of the regionally extensive Peach Spring Tuff (PST). Here we compare zircon age and geochemical analyses from the Shamrock tuff with those of the PST at Stoddard Wash and provide new insight into the age of zircon crystallization in the PST rhyolite. Results of our field studies show that Miocene strata at Harvard Hill mostly accumulated in a lacustrine environment, although depositional environments varied from a relatively deep lake to a very shallow lake or even onshore setting. Rock-avalanche breccias and alluvial deposits near the base of the exposed section indicate proximity to a steep basin margin and detrital studies suggest a southern source for coarse-grained deposits; therefore, we may infer a southern basin-margin setting at Harvard Hill during the early Miocene. Our geochronology demonstrates that deposition of the Barstow Formation at Harvard Hill extended from before

Geologic map of the Fraser 7.5-minute quadrangle, Grand County, Colorado

Science.gov (United States)

Shroba, Ralph R.; Bryant, Bruce; Kellogg, Karl S.; Theobald, Paul K.; Brandt, Theodore R.

2010-01-01

The geologic map of the Fraser quadrangle, Grand County, Colo., portrays the geology along the western boundary of the Front Range and the eastern part of the Fraser basin near the towns of Fraser and Winter Park. The oldest rocks in the quadrangle include gneiss, schist, and plutonic rocks of Paleoproterozoic age that are intruded by younger plutonic rocks of Mesoproterozoic age. These basement rocks are exposed along the southern, eastern, and northern margins of the quadrangle. Fluvial claystone, mudstone, and sandstone of the Upper Jurassic Morrison Formation, and fluvial sandstone and conglomeratic sandstone of the Lower Cretaceous Dakota Group, overlie Proterozoic rocks in a small area near the southwest corner of the quadrangle. Oligocene rhyolite tuff is preserved in deep paleovalleys cut into Proterozoic rocks near the southeast corner of the quadrangle. Generally, weakly consolidated siltstone and minor unconsolidated sediments of the upper Oligocene to upper Miocene Troublesome Formation are preserved in the post-Laramide Fraser basin. Massive bedding and abundant silt suggest that loess or loess-rich alluvium is a major component of the siltstone in the Troublesome Formation. A small unnamed fault about one kilometer northeast of the town of Winter Park has the youngest known displacement in the quadrangle, displacing beds of the Troublesome Formation. Surficial deposits of Pleistocene and Holocene age are widespread in the Fraser quadrangle, particularly in major valleys and on slopes underlain by the Troublesome Formation. Deposits include glacial outwash and alluvium of non-glacial origin; mass-movement deposits transported by creep, debris flow, landsliding, and rockfall; pediment deposits; tills deposited during the Pinedale and Bull Lake glaciations; and sparse diamictons that may be pre-Bull Lake till or debris-flow deposits. Some of the oldest surficial deposits may be as old as Pliocene.

Computer model for determining fracture porosity and permeability in the Conasauga Group, Oak Ridge National Laboratory, Tennessee

International Nuclear Information System (INIS)

Sledz, J.J.; Huff, D.D.

1981-04-01

Joint orientations for the shale and siltstone beds of the Conasauga Group were measured from outcrop exposures on the Oak Ridge National Laboratory Reservation. The data collected from two strike belts (structural trends) were analyzed with the use of the computer and subdivided into individual joint sets. The joint set patterns in the Northern outcrop belt were too complex for orientation prediction; joint formation is believed to be influenced by polyphase deformation. The Southern Conasauga Belt contains an orthogonal joint set consisting of strike and a-c joints in all outcrops measured. These are believed to be tension joints formed during thrust sheet emplacement. Joint length and spacing, measured in the field, were found to be extremely variable within each exposure and highly dependent upon surficial weathering. The measurements from all locations were combined for detailed analysis and trend prediction. Results showed that the joint length and spacing increased with increasing bed thickness in the siltstone, while the bed thickness variations in the shale had little effect on the joints. A computer model was developed by combining the joint orientation, joint spacing, and joint length data collected in the field with subsurface drill core information for the purpose of calculating the fracture porosity and permeability of the rocks. The joint gap width was measured from both outcrop and subsurface samples with ranges from 0.1 mm to 0.7 mm in the siltstones and less than 0.2 mm in the shales. The value for the joint gap width was found to be the major factor in the fracture porosity and permeability calculation

The Cannery Formation--Devonian to Early Permian arc-marginal deposits within the Alexander Terrane, Southeastern Alaska

Science.gov (United States)

Karl, Susan M.; Layer, Paul W.; Harris, Anita G.; Haeussler, Peter J.; Murchey, Benita L.

2011-01-01

The Cannery Formation consists of green, red, and gray ribbon chert, siliceous siltstone, graywacke-chert turbidites, and volcaniclastic sandstone. Because it contains early Permian fossils at and near its type area in Cannery Cove, on Admiralty Island in southeastern Alaska, the formation was originally defined as a Permian stratigraphic unit. Similar rocks exposed in Windfall Harbor on Admiralty Island contain early Permian bryozoans and brachiopods, as well as Mississippian through Permian radiolarians. Black and green bedded chert with subordinate lenses of limestone, basalt, and graywacke near Kake on Kupreanof Island was initially correlated with the Cannery Formation on the basis of similar lithology but was later determined to contain Late Devonian conodonts. Permian conglomerate in Keku Strait contains chert cobbles inferred to be derived from the Cannery Formation that yielded Devonian and Mississippian radiolarians. On the basis of fossils recovered from a limestone lens near Kake and chert cobbles in the Keku Strait area, the age of the Cannery Formation was revised to Devonian and Mississippian, but this revision excludes rocks in the type locality, in addition to excluding bedded chert on Kupreanof Island east of Kake that contains radiolarians of Late Pennsylvanian and early Permian age. The black chert near Kake that yielded Late Devonian conodonts is nearly contemporaneous with black chert interbedded with limestone that also contains Late Devonian conodonts in the Saginaw Bay Formation on Kuiu Island. The chert cobbles in the conglomerate in Keku Strait may be derived from either the Cannery Formation or the Saginaw Bay Formation and need not restrict the age of the Cannery Formation, regardless of their source. The minimum age of the Cannery Formation on both Admiralty Island and Kupreanof Island is constrained by the stratigraphically overlying fossiliferous Pybus Formation, of late early and early late Permian age. Because bedded radiolarian

Hydrogeological Modelling of Some Geothermal Waters of Ivrindi, Havran and Gönen in the Province Capital of Balikesir, Western Anatolia, Turkey

Science.gov (United States)

Özgür, Nevzat; Ugurlu, Zehra; Memis, Ümit; Aydemir, Eda

2017-12-01

In this study, hydrogeological, hydrogeochemical and isotope geochemical features of Havran, Gönen and Ivrindi within the province capital of Balıkesir, Turkey were investigated in detail. The Early Triassic Karakaya formation in the study area of Havran forms the oldest rocks consisting of spilitic basalts, diabases, gabbros, mudstones, cherts and radiolarites. There are limestone blocks in this formation with intercalations with sandstones and with feldspar contents, quartzite, conglomerates and siltstones. Oligocene to Miocene granodiorite intrusions were generated in association with intensively volcanic events in the area. Between Upper Oligocene and Early Miocene, andesitic and dacitic pyroclastic rocks cropped out due to intensively volcanism. Later, conglomerates, sandstones, claystones, marls and limestones as lacustrine sediments formed from Middle to Upper Miocene in the study area. In the study area of Gönen, the Lower Triassic Karakaya formation consists of basalts, diabases, gabbros, mudstones, cherts and radiolarites and forms the basement rocks overlain by Upper Jurassic to Lower Cretaceous sandy limestones. Upper and Middle Miocene volcanics which can be considered intensive Biga Peninsula volcanos outcrop in the area. These andesitic lava flows are of black, gray and red color with intensive fissures. Neogene lacustrine sediments consist of conglomerates, sandstones, marl, claystone and clayey limestones. Upper Miocene to Pliocene rhyolitic pyroclastics and dacitic lava flows are the volcanic rocks which are overlain by Pliocene conglomerates, sandstones and claystones. In the study area of Ivrindi, the Çaldağ limestones are the oldest formation in Permian age. Çavdartepe metamorphic rocks are of Lower Triassic in which can be observed marbles sporadically. The Kınık formation consisting of conglomerates, sandstones, siltstones and limestones are of Lower Triassic age and display a lateral Stratigraphic progress with volcanic rocks. Upper

Brackish to hypersaline lake dolostones of the Mississippian

Science.gov (United States)

Bennett, Carys; Kearsey, Timothy; Davies, Sarah; Millward, David; Marshall, John

2016-04-01

Flat-lying ferroan dolomite beds are common in the Mississippian and occur along the southern margin of Laurassia, from Kentucky USA to Poland. These rocks are important as they record shallow marine to coastal plain environments that may have acted as a pathway or refugia for animals that were radiating into freshwaters such as tetrapods, fish, molluscs and arthropods. This study is a contribution to the TW:eed Project (Tetrapod World: early evolution and diversification), that examines the rebuilding of Carboniferous ecosystems following a mass extinction at the end of the Devonian. The project focuses on the Tournaisian Ballagan Formation of Scotland, which contains rare fish and tetrapod fossils. The formation is characterised by an overbank facies association of siltstone, sandstone and palaeosols, interbedded with dolostone and evaporite units, and cut by fluvial sandstone facies associations of fining-upwards conglomerate lags, cross-bedded sandstone and rippled siltstone. Two sites are used as a case study to describe the sedimentological, faunal and ichnofaunal diversity of these dolostones. More than 270 dolostone beds are recorded in each of the 500 metre depth Norham Core (near Berwick-upon-Tweed) and from a 520 metre thick field section at Burnmouth. The beds are laterally extensive, over ˜1 km, although individual units do not appear to correlate between the core and the field site. In the Norham Core dolostones comprise up to 14% of the succession. 17% of the beds contain marginal marine fossils: Spirorbis, rare orthocones, brachiopods and putative marine sharks. More common fauna include ostracods, bivalves, plants, eurypterids, gastropods and sarcopterygian fish, which are interpreted as brackish to freshwater tolerant. Bioturbation is fairly common with Serpula colonies within dolostone beds and Chondrites burrowing down from the base of dolostone beds. Some rare units in the field section have a bulbous bed surface and preserve tree root traces

The Jurassic of Denmark and Greenland: Shallow marine syn-rift sedimentation: Middle Jurassic Pelion Formation, Jameson Land, East Greenland

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Engkilde, Michael

2003-10-01

Full Text Available The Middle Jurassic Pelion Formation – Fossilbjerget Formation couplet of Jameson Land, East Greenland, is a well-exposed example of the Middle Jurassic inshore–offshore successions characteristicof the rifted seaways in the Northwest European – North Atlantic region. Early Jurassic deposition took place under relatively quiet tectonic conditions following Late Permian – earliest Triassic and Early Triassic rift phases and the Lower Jurassic stratal package shows an overall layer-cake geometry. A long-term extensional phase was initiated in Middle Jurassic (Late Bajocian time, culminated in the Late Jurassic (Kimmeridgian–Volgian, and petered out in the earliest Cretaceous (Valanginian. The Upper Bajocian – Middle Callovian early-rift succession comprises shallow marine sandstones of the Pelion Formation and correlative offshore siltstones of theFossilbjerget Formation. Deposition was initiated by southwards progradation of shallow marine sands of the Pelion Formation in the Late Bajocian followed by major backstepping in Bathonian–Callovian times and drowning of the sandy depositional system in the Middle–Late Callovian. Six facies associations are recognised in the Pelion–Fossilbjerget couplet, representing estuarine, shoreface, offshore transition zone and offshore environments. The north–southtrendingaxis of the Jameson Land Basin had a low inclination, and deposition was sensitive to even small changes in relative sea level which caused the shorelines to advance or retreat over tens to several hundreds of kilometres. Eight composite sequences, termed P1–P8, are recognised and are subdivided into a total of 28 depositional sequences. The duration of the two orders of sequences was about 1–2 Ma and 360,000 years, respectively. The Upper Bajocian P1–2 sequencesinclude the most basinally positioned shallow marine sandstones, deposited during major sealevel lowstands. The lowstands were terminated by significant marine

Hydraulic evolution of high-density turbidity currents from the Brushy Canyon Formation, Eddy County, New Mexico inferred by comparison to settling and sorting experiments

Science.gov (United States)

Motanated, Kannipa; Tice, Michael M.

2016-05-01

Hydraulic transformations in turbidity currents are commonly driven by or reflected in changes in suspended sediment concentrations, but changes preceding transformations can be difficult to diagnose because they do not produce qualitative changes in resultant deposits. This study integrates particle settling experiments and in situ detection of hydraulically contrasting particles in turbidites in order to infer changes in suspended sediment concentration during deposition of massive (Bouma Ta) sandstone divisions. Because grains of contrasting density are differentially sorted during hindered settling from dense suspensions, relative grading patterns can be used to estimate suspended sediment concentrations and interpret hydraulic evolution of the depositing turbidity currents. Differential settling of dense particles (aluminum ballotini) through suspensions of hydraulically coarser light particles (silica ballotini) with volumetric concentration, Cv, were studied in a thin vessel by using particle-image-velocimetry. At high Cv, aluminum particles were less retarded than co-sedimenting silica particles, and effectively settled as hydraulically coarser grains. This was because particles were entrained into clusters dominated by the settling behavior of the silica particles. Terminal settling velocities of both particles converged at Cv ≥ 25%, and particle sorting was diminished. The results of settling experiments were applied to understand settling of analogous feldspar and zircon grains in natural turbidity flows. Distributions of light and heavy mineral grains in massive sandstones, Bouma Ta divisions, of turbidites from the Middle Permian Brushy Canyon Formation were observed in situ by X-ray fluorescence microscopy (μXRF). Hydraulic sorting of these grains resulted in characteristic patterns of zirconium abundance that decreased from base to top within Ta divisions. These profiles resulted from upward fining of zircon grains with respect to co

Basic results and tasks of exploratory work at the Samgorskiy area of the Georgian SSR

Energy Technology Data Exchange (ETDEWEB)

Konavalov, V I; Gordiyenko, Yu I; Serkin, V G; Yalovenko, V I

1979-01-01

In 1974 in well 7 at the Samgorskiy field, an influx of oil was obtained from the middle Eocene deposits. As a result of exploratory and operational drilling, it was established that oil in the deposit is confined to volcanic and volcanogenic-sedimentary formations of the middle Eocene age. It was revealed by wells at depth 2250-3050 m. The upper part of the section is represented by limestones, marls, peat-origin sandstones, aleurolites, etc. Secondary cavities are noted which are opened and filled with mineral substance or bitumen of the crack. The porosity of the middle Eocene rocks changes from 0.4 to 13.8%, gas permeability from 0.001 to 0.41 mdarcy. Permeability of the working intervals equals 0.26-160 mdarcy. The output of the well reaches 500 T/day. These samplings are guaranteed by filtering mainly in the open microfractures. Currently 32 wells are in operation which are operating with anhydrous oil. In the wells not all the revealed interval of middle Eocene deposits is operating, but 14-57%. Information has been obtained on the type of rocks, their collector properties, hydrodynamics of the formation, etc. However because of the preparation of the oil formation for calculation of the reserves, the shortage of information makes it difficult to have a qualitative fulfillment of this work. A sufficient number of core samples and the use of methods of neutron-neutron, density and acoustic logging are necessary. In calculating the reserves of hydrocarbon, in addition to the volumetric method, it is desirable to use the method of material balance. Additional information can be obtained with the use of a drilling core lifter. It is necessary in uniformly arranged wells to perform by-interval testing of objects with the use of cemented liners.

Basic data report for Drillhole ERDA 10 (Waste Isolation Pilot Plant - WIPP)

International Nuclear Information System (INIS)

1983-02-01

Borehole ERDA 10 was drilled to obtain information on possible dissolution of halite within the Castile Formation and on the hydrologic characteristics of the fluid-bearing zones in the Bell Canyon Formation. The borehole is located in Section 34, T23S,R30E in southern Eddy County, New Mexico. ERDA 10 was drilled to a depth of 4431.5 ft. Cores from the Castile were taken to obtain direct information which was supplemented by geophysical logging. Based on preliminary analysis of the data, the ERDA 10 stratigraphic section is interpreted as a sequence of sandstones, siltstones, claystones, and evaporites normal for the area. No evidence of dissolution of significant amounts of halite was observed

Geology and ground water in north-central Santa Cruz County, California

Science.gov (United States)

Johnson, Michael J.

1980-01-01

North-central Santa Cruz County is underlain mainly by folded sedimentary rocks of Tertiary and Cretaceous age that have been highly fractured by movements in the San Andreas fault system. Ground water is stored in fractures within shale and mudstone formations and in intergranular pore spaces within fine- to very fine-grained sandstone and siltstone formations. Fewer than 10% of the wells yield more than 15 gallons of water per minute. The water in most wells is moderately hard to very hard, is generally of a sodium bicarbonate or calcium bicarbonate type, and commonly has excessive concentrations of iron or manganese. Of the many geologic units in the study area, only the Purisima Formation of Pliocene age has the potential to sustain well yields greater than 100 gallons per minute. (USGS)

The Frasnian-Famennian boundary (Upper Devonian) within the Hanover-Dunkirk transition, northern Appalachian basin, western New York state

Energy Technology Data Exchange (ETDEWEB)

Over, D.J. (State Univ. of New York, Geneseo, NY (United States))

1993-03-01

In western New York State interbedded pyritic silty green and dark grey shales and siltstone of the Hanover Member, Java Formation, West Falls Group, are overlain by thick pyritic dark grey-black shale of the Dunkirk Member of the Canadaway formation. The dark shales in the upper Hanover and Dunkirk contain a diverse and well preserved conodont fauna which allows precise placement of the Frasnian-Famennian boundary at several described sections. At Pt. Gratiot, in far western New York State, the contact between the Hanover and Dunkirk is disconformable. The Frasnian-Famennian boundary is marked by a pyritic lag deposit at the base of the Dunkirk which contains Palmatolepis triangularis and Pa. subperlobata. The underlying upper Hanover is characterized by Pa. bogartensis , Pa. cf. Pa. rhenana, Pa. winchelli, and Ancyrognathus (asymmetricus/calvini) Eastward, in the direction of the paleo-source area, the Frasnian-Famennian boundary is within the upper Hanover Member. At Irish Gulf the boundary is recognized within a 10 cm thick laminated pyritic dark grey shale bed 3.0 m below the base of the Dunkirk. Palmatolepis triangularis and Pa. subperlobata occur below a conodont-rich lag layer in the upper 2 cm of the bed. Palmatolepis bogartensis , Pa. cf. Pa. rhenana, Ancyrodella curvata, and Icriodus alternatus occur in the underlying 8 cm. Palmatolepis triangularis and Pa. winchelli occur in an underlying dark shale bed separated from the boundary bed by a hummocky cross-bedded siltstone layer.

Paleozoic stratigraphy and tectonics in northernmost Nevada: Implications for the nature of the Antler orogeny

Energy Technology Data Exchange (ETDEWEB)

Ketner, K.B. (Geological Survey, Denver, CO (United States)); Ehman, K.D. (Exxon Production Research Co., Houston, TX (United States)); Repetski, J.E.; Stamm, R.G.; Wardlaw, B.R. (Geological Survey, Reston, VA (United States))

1993-04-01

Recent mapping and revised ages have clarified geologic relations in northern Nevada. In the Bull Run Mountains-Copper Mountains area, Proterozoic quartzite, phyllite, marble, and greenstone are overlain successively, depositionally, and nearly concordantly by the Cambrian Prospect Mountain Quartzite, Pioche Shale, and Eldorado Dolomite; the Cambrian to Ordovician Tennessee Mountain Formation composed of limestone, siltstone, and greenstone; the Ordovician Valmy Formation composed of a lower member of greenstone, limestone, mudstone, and chert, and an upper member of quartzite and argillite; and, disconformably by a Mississippian sequence of interbedded conglomerate, limestone, siltstone, and greenstone. The Prospect Mountain, Pioche, and Eldorado form a relatively shallow-water, shelf sequence containing trilobites and displaying cross-bedding, ooliths, oncolites, and fenestral fabric. The overlying Tennessee Mountain and Valmy are devoid of such features and contain many black, finely laminated, and graded strata, suggesting a deeper-water environment. This upper Proterozoic to Permian sequence is interpreted as indicating: (1) increased tectonic subsidence or sea-level rise in the latter part of the Cambrian; (2) elevation above sea level and erosion of Devonian, Silurian, and Upper Ordovician rocks in earliest Mississippian; (3) subsidence below sea level in later Early Mississippian; (4) elevation above sea level with sporadic, moderate deformation, and local, deep erosion in medial Pennsylvanian; (5) subsidence below sea level in medial Pennsylvanian or later; (6) intermittent eruption of basic volcanics peaking in Early Ordovician and again in Mississippian. The disconformable relation between the Valmy Formation and overlying Mississippian strata indicates that the Antler orogeny of earliest Mississippian age, here consisted primarily of uplift and deep erosion. Evidence of strong Early Mississippian folding and contractional faulting is not apparent.

Impact of solid second phases on deformation mechanisms of naturally deformed salt rocks (Kuh-e-Namak, Dashti, Iran) and rheological stratification of the Hormuz Salt Formation

Science.gov (United States)

Závada, P.; Desbois, G.; Urai, J. L.; Schulmann, K.; Rahmati, M.; Lexa, O.; Wollenberg, U.

2015-05-01

Viscosity contrasts displayed in flow structures of a mountain namakier (Kuh-e-Namak - Dashti), between 'weak' second phase bearing rock salt and 'strong' pure rock salt types are studied for deformation mechanisms using detailed quantitative microstructural study. While the solid inclusions rich ("dirty") rock salts contain disaggregated siltstone and dolomite interlayers, "clean" salts reveal microscopic hematite and remnants of abundant fluid inclusions in non-recrystallized cores of porphyroclasts. Although the flow in both, the recrystallized "dirty" and "clean" salt types is accommodated by combined mechanisms of pressure-solution creep (PS), grain boundary sliding (GBS), transgranular microcracking and dislocation creep accommodated grain boundary migration (GBM), their viscosity contrasts observed in the field outcrops are explained by: 1) enhanced ductility of "dirty" salts due to increased diffusion rates along the solid inclusion-halite contacts than along halite-halite contacts, and 2) slow rates of intergranular diffusion due to dissolved iron and inhibited dislocation creep due to hematite inclusions for "clean" salt types Rheological contrasts inferred by microstructural analysis between both salt rock classes apply in general for the "dirty" salt forming Lower Hormuz and the "clean" salt forming the Upper Hormuz of the Hormuz Formation and imply strain rate gradients or decoupling along horizons of mobilized salt types of different composition and microstructure.

Geologic Reconnaissance of the Antelope-Ashwood Area, North-Central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age

Science.gov (United States)

Peck, Dallas L.

1964-01-01

This report briefly describes the geology of an area of about 750 square miles in Jefferson, Wasco, Crook, and Wheeler Counties, Oregon. About 16,000 feet of strata that range in age from pre-Tertiary to Quaternary are exposed. These include the following units: pre-Tertiary slate, graywacke, conglomerate, and meta-andesite; Clarno Formation of Eocene age - lava flows, volcanic breccia, tuff, and tuffaceous mudstone, chiefly of andesitic composition; John Day Formation of late Oligocene and early Miocene age - pyroclastic rocks, flows, and domes, chiefly of rhyolitic composition; Columbia River Basalt of middle Miocene age - thick, columnar jointed flows of very fine grained dense dark-gray basalt; Dalles Formation of Pliocene age - bedded tuffaceous sandstone, siltstone, and conglomerate; basalt of Pliocene or Pleistocene age - lava flows of porous-textured olivine basalt; and Quaternary loess, landslide debris, and alluvium. Unconformities separate pre-Tertiary rocks and Clarno Formation, Clarno and John Day Formations, John Day Formation and Columbia River Basalt, and Columbia River Basalt and Dalles Formation. The John Day Formation, the only unit studied in detail, consists of about 4,000 feet of tuff, lapilli tuff, strongly to weakly welded rhyolite ash flows, and less abundant trachyandesite flows and rhyolite flows and domes. The formation was divided into nine mappable members in part of the area, primarily on the basis of distinctive ledge-forming welded ash-flow sheets. Most of the sheets are composed of stony rhyolite containing abundant lithophysae and sparse phenocrysts. One sheet contains 10 to 20 percent phenocrysts, mostly cryptoperthitic soda sanidine, but including less abundant quartz, myrmekitic intergrowths of quartz and sanidine, and oligoclase. The rhyolitic ash flows and lava flows were extruded from nearby vents, in contrast to some of the interbedded air-fall tuff and lapilli tuff of dacitic and andesitic composition that may have been

Preliminary Assessment McGhee - Tyson ANGB, McGhee - Tyson Municipal Airport, Knoxville, Tennessee

Science.gov (United States)

1988-06-01

shales and siltstones are 700.2000 .0 brown, brownish gray, medium to dark gray. lossililerous. calcareous: limestones are argillaceous to pure , gray...shale. PUMPKIN Shale and siltstone, reddish-brown to qsoyish-red. gteenish~gtary and 100-750 VALLEY SHALE oliv*egray: with thin sandstones. limestones...Rogersville shale Wrt..............Cambrian Rutledge limestone Ipv ..............Cambrian Pumpkin Valley ................... Cambrian Rome Figure 111.2

On the presence of upper paleocene rocks in the foreland succession at Cabo Nariz, Tierra del Fuego, Chile: Geology and new palynological and U-Pb data

International Nuclear Information System (INIS)

Sanchez, Alejandro; Pavlishina, Polina; Godoy, Estanislao; Herve, Francisco; Fanning, C.Mark

2010-01-01

On the west coast of Tierra del Fuego, south of Cabo Nariz, in Chile, Upper Cretaceous to Paleocene sedimentary successions of the Magallanes foreland basin crop out. The presence of dinoflagellate cysts, as well as radiometric U-Pb SHPJMP dating of detrital zircons, indicate that this succession ranges from the Campanian to Thanetian (Late Paleocene) in age. The base of the exposed sedimentary succession comprises siltstones of external platform facies (Cerro Cuchilla Formation), which are thrust over the Cabo Nariz Beds. The latter fonnation is divided into two members: a lower siltstone-dominated turbidite facies member and an upper member of sandstone-dominated turbidites, with sandstone and conglomerate channel facies. The presence of dinocysts in the Cerro Cuchilla Formation suggests a late Campanian to early Danian age. The fossil content in the Cabo Nariz Beds indicate a Selandian (Middle Paleocene) depositional age in accordance with the detrital zircon ages which provide a maximum possible Campanian age (76.5±0.7 Ma), and very close to the Thanetian (Late Paleocene) (57.6±1 Ma) depositional ages for the lower and upper member, respectively. The sedimentary succession of Cabo Nariz Beds, is interpreted as a north-northwest prograding submarine fan of middle to Late Paleocene age. It is considered to represent the deposition of detritus derived from an uplifting orogen located to the south. The detrital zircon age spectra suggest that there was a period of low intensity of magmatic activity in the source area around the K-T boundary

Organic geochemistry of the Dongsheng sedimentary uranium ore deposits, China

International Nuclear Information System (INIS)

Tuo Jincai; Ma Wanyun; Zhang Mingfeng; Wang Xianbin

2007-01-01

Organic matter (OM) associated with the Dongsheng sedimentary U ore hosting sandstone/siltstone was characterized by Rock-Eval, gas chromatography-mass spectrometry and stable C isotope analysis and compared to other OM in the sandstone/siltstone interbedded organic matter-rich strata. The OM in all of the analyzed samples is Type III with Ro less than 0.6%, indicating that the OM associated with these U ore deposits can be classified as a poor hydrocarbon source potential for oil and gas. n-Alkanes in the organic-rich strata are characterized by a higher relative abundance of high-molecular-weight (HMW) homologues and are dominated by C 25 , C 27 or C 29 with distinct odd-to-even C number predominances from C 23 to C 29 . In contrast, in the sandstone/siltstone samples, the n-alkanes have a higher relative abundance of medium-molecular-weight homologues and are dominated by C 22 with no or only slight odd-to-even C number predominances from C 23 to C 29 . Methyl alkanoates in the sandstone/siltstone extracts range from C 14 to C 30 , maximizing at C 16 , with a strong even C number predominance, but in the organic-rich layers the HMW homologues are higher, maximizing at C 24 , C 26 or C 28 , also with an even predominance above C 22 . n-Alkanes in the sandstone/siltstone sequence are significantly depleted in 13 C relative to n-alkanes in most of the organic-rich strata. Diasterenes, ββ-hopanes and hopenes are present in nearly all the organic-rich sediments but in the sandstone/siltstone samples they occur as the geologically mature isomers. All the results indicate that the OM in the Dongsheng U ore body is derived from different kinds of source materials. The organic compounds in the organic-rich strata are mainly terrestrial, whereas, in the sand/siltstones, they are derived mainly from aquatic biota. Similar distribution patterns and consistent δ 13 C variations between n-alkanes and methyl alkanoates in corresponding samples suggest they are derived from

Recent Compositional Trends within the Murray Formation, Gale Crater, Mars, as seen by APXS: Implications for Sedimentary, Diagenetic and Alteration History.

Science.gov (United States)

Thompson, L. M.; Yen, A.; Spray, J. G.; Johnson, J. R.; Fraeman, A. A.; Berger, J. A.; Gellert, R.; Boyd, N.; Desouza, E.; O'Connell-Cooper, C.; VanBommel, S.

2017-12-01

The >230 m thick Murray Formation is the lower-most unit of the Mount Sharp Group, and interpreted as primarily lacustrine. Representative mudstone, siltstone and fine sandstone targets, encountered above -4330 m elevation, trend to lower Si, Al, Ti, Cr and Ca, and higher Fe, Mn, Zn, P and Mg than the Murray below. Less common, distinctive, coarser grained sandstone lenses tend to exhibit slightly different compositions to the more typical Murray but, overall, show similar elemental trends with elevation, albeit exaggerated. This suggests that the variations observed with elevation in Al, Ti, Cr, K, Fe, Mn, Zn and P within both the coarser sandstones and finer grained Murray are the result of diagenetic and/or alteration processes rather than provenance or physical sedimentary processes such as sorting. This is supported by the chemistry of obvious diagenetic, dark grey nodules, and other potential diagenetic/alteration features within this section, which show variations in the same element concentrations (i.e., P, Mn, Fe, Zn, Mg, Ca and S), distinct from diagenetic features lower down in the stratigraphy, indicating mobility of these elements within this section and changing fluid chemistry. Trends in FeO/MnO generally mimic the presence of ferric absorption features observed in visible/near infrared passive spectra from the ChemCam instrument and from CRISM orbital data, which may be consistent with changes in redox conditions as we climb up section towards Vera Rubin Ridge (Hematite Ridge). Layer-parallel CaSO4 is also common, and not observed below -4330 m. This may represent syndepositional evaporite layers, or late bedding/laminae parallel veins emplaced after lithification, in conjunction with cross-cutting veins. The overall differences in composition between the sandstone targets and finer grained Murray are attributed to distinct provenances and/or sorting during transport. We will discuss the implications of the trends and composition of the Murray above

Stratigraphy of Eocene Sediments in the Soutwest Thrace

Directory of Open Access Journals (Sweden)

Muhsin SÜMENGEN

1991-06-01

siltstone, mudstone, and conglomerate, which become thick bedded and coarser upward (Korudağ formation and fining upward sequences (Keşan formation. These are submarine fan deposits of turbiditic origin. The basin became shallower again towards the end of Upper Eocene. During this period, rock units made up of mudstone, siltstone, sandstone, and conglomerate were deposited. This sequence deposited in a deltaic environment has been named differently, the Kanlıbent formation in the Gelibolu peninsula and the Yenimuhacir formation between Keşan and Tekirdağ, due to its diverse local features. The basin as a whole became a continent during the Oligocene (? and alluvial deposits that consist of mudstone, sandstone, and conglomerate formed (Armuttepe formation.

Coalbed methane potential of the Upper Cretaceous Mesaverde and Meeteetse formations, Wind River Reservation, Wyoming

Science.gov (United States)

Johnson, R.C.; Clark, A.C.; Barker, C.E.; Crysdale, B.L.; Higley, D.K.; Szmajter, R.J.; Finn, T.M.

1993-01-01

The environments of deposition of the uppermost part of the Cody Shale and the Mesaverde and Meeteetse Formations of Late Cretaceous age were studied on outcrop in the Shotgun Butte area in the north-central part of the Wind River Reservation. A shoreface sandstone occurs in the lower part of the Mesaverde Formation at all localities studied, and is directly overlain by a coaly interval. Repetitive coarsening-upward cycles of mudstone, siltstone, and sandstone occur in the 200 ft interval of the upper part of the Cody Shale below the shoreface sandstone. These Cody sandstones are typically hummocky cross stratified with symmetrical ripples near the top, indicating that they are largely storm surge deposits that were later reworked. Channel-form sandstones from 10 to 20 ft thick, with abundant locally derived clayey clasts, occur in a 75 ft thick interval below the shoreface at one locality. These unusual sandstones are largely confined to a narrow area of the outcrop and grade laterally into more typical storm surge deposits. They may be unusually large storm surge channels created when high-energy flow conditions were localized to a limited area of the shelf.The Mesaverde Formation above the shoreface sandstone is divided into a middle member and the Teapot Sandstone Member. The lower part of the middle member is everywhere coaly. Erosional-based sandstones in this coaly interval are highly variable in thickness and architecture. Thin, single channel sandstone bodies were deposited by moderate to high sinuosity streams, and thick, multistory channel sandstone bodies were deposited by rapidly switching fluvial channel systems that remained relatively stationary for extended periods of time. The architecture of the fluvial channel sandstones in the overlying noncoaly interval appears to be highly variable as well, with complex multistory sandstones occurring at different stratigraphic levels at different localities. This distribution may be explained by long term

Bedrock cores from 89° North: Implications for the geologic framework and Neogene paleoceanography of Lomonosov Ridge and a tie to the Barents shelf

Science.gov (United States)

Grantz, Arthur; Pease, Victoria L.; Willard, Debra A.; Phillips, R.L.; Clark, David L.

2001-01-01

Two piston cores from the Eurasian flank of Lomonosov Ridge near lat 88.9°N, long 140°E provide the first samples of bedrock from this high-standing trans-Arctic ridge. Core 94-PC27 sampled nonmarine siltstone similar in facies and age to uppermost Triassic to lower Lower Jurassic and mid– Lower Cretaceous beds in the 4 to > 5 km Mesozoic section on Franz Josef Land, on the outer Barents shelf. A ca. 250 Ma peak in the cumulative frequency curve of detrital zircons from the siltstone, dated by U- Th-Pb analysis, suggests a source in the post-tectonic syenites of northern Taymyr and nearby islands in the Kara Sea. Textural trends reported in the literature indicate that the Lower Jurassic nonmarine strata of Franz Josef Land coarsen to the southeast; this suggests the existence of a sedimentary system in which detrital zircons could be transported from the northern Taymyr Peninsula to the outer Barents shelf near the position of core 94-PC27 prior to opening of the Eurasia Basin. Correlation of the coaly siltstone in core 94-PC27 with part of the Mesozoic section on Franz Josef Land is compatible with the strong evidence from seafloor magnetic anomalies and bathymetry that Lomonosov Ridge is a continental fragment rifted from the Barents shelf during the Cenozoic. It also suggests that Lomonosov Ridge near the North Pole is underlain by a substantial section of unmetamorphosed Mesozoic marine and nonmarine sedimentary strata. Core 94-PC29 sampled cyclical deposits containing ice-rafted debris (IRD) overlying weakly consolidated laminated olive-black anoxic Neogene siltstone and mudstone with an average total organic carbon (TOC) of 4.1 wt%. The high TOC content of the mudstone indicates that during the Neogene, prior to the introduction of IRD into the Arctic seas about 3.3 Ma (early late Pliocene), the shallow waters of the central Arctic Ocean supported significant primary photosynthetic organic production near the North Pole. These deposits also contain fine

Uranium laterite from Ipora/Amorinopolis region- Goias, Brazil

International Nuclear Information System (INIS)

Fernandes, S.M.

1983-01-01

The present study gives an account of the uranium bearing laterite in the district of Amorinopolis, GO. Emphasis is given in the study of its mineralogy and of the mineralization controls. The uranium mineralization is chiefly found within the arkosic sandstones at the base of the Devonian Ponta Grossa Formation. The ore is tabular and concordant with the bedding, the controls being simultaneously litho-stratigraphic and biochemical. Narrow permeable horizons of arkosic sandstone lie between impermeable shale an siltstone layers. Within the permeable horizon fossil remains (probably brachiopods) are replaced by uranium minerals. The oxidized iron minerals may have acted to insulate and preserve the secondary soluble uranium minerals. (author)

Geologic characterization report for the Paradox Basin Study Region, Utah Study Areas. Volume 6: Salt Valley

Science.gov (United States)

1984-12-01

Surface landforms in the Salt Valley Area are generally a function of the Salt Valley anticline and are characterized by parallel and subparallel cuestaform ridges and hogbacks and flat valley floors. The most prominent structure in the Area is the Salt Valley anticline. Erosion resulting from the Tertiary uplift of the Colorado Plateau led to salt dissolution and subsequent collapse along the crest of the anticline. Continued erosion removed the collapse material, forming an axial valley along the crest of the anticline. Paleozoic rocks beneath the salt bearing Paradox Formation consist of limestone, dolomite, sandstone, siltstone and shale. The salt beds of the Paradox formation occur in distinct cycles separated by an interbed sequence of anhydrite, carbonate, and clastic rocks. The Paradox Formation is overlain by Pennsylvanian limestone; Permian sandstone; and Mesozoic sandstone, mudstone, conglomerate and shale. No earthquakes have been reported in the area during the period of the historic record and contemporary seismicity appears to be diffusely distributed, of low level and small magnitude. The upper unit includes the Permian strata and upper Honaker trail formation.

Ways of increasing safety in mining at the Berezovskii-1 surface mine

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, N N; Malyarenko, V I

1986-12-01

Methods are descrubed wgucg were developed to alleviate or prevent the effects of landslides in a Kansk-Achinsk surface mine. Such a landslide took place in 1983 at the Berezovskii-1 mine when 250 m of an excavation trench suffered a collapse involving 680,000 mT of materials. Surveys revealed large zones of flooded ground with high proportions of argillites and aleurolites which swell in the presence of water. To keep costs down, a method using gravity is proposed for safety of re-excavation work near spoil banks. In this method a pillar of rock is left at the base of the spoil bank, the edge of the slope of which is moved back from the trench. Hard rock is placed at the leading edge of the spoil bank. The stability factor of the trench side may be raised from 0.87 to 1.12, and this is accompanied by savings in labor and costs.

Assessment of the potential for karst in the Rustler Formation at the WIPP site

International Nuclear Information System (INIS)

Lorenz, John Clay

2006-01-01

This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

Assessment of the potential for karst in the Rustler Formation at the WIPP site.

Energy Technology Data Exchange (ETDEWEB)

Lorenz, John Clay

2006-01-01

This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

Geologic map of the Strawberry Butte 7.5’ quadrangle, Meagher County, Montana

Science.gov (United States)

Reynolds, Mitchell W.; Brandt, Theodore R.

2017-06-19

The 7.5′ Strawberry Butte quadrangle in Meagher County, Montana near the southwest margin of the Little Belt Mountains, encompasses two sharply different geologic terranes.  The northern three-quarters of the quadrangle are underlain mainly by Paleoproterozoic granite gneiss, across which Middle Cambrian sedimentary rocks rest unconformably.  An ancestral valley of probable late Eocene age, eroded northwest across the granite gneiss terrane, is filled with Oligocene basalt and overlying Miocene and Oligocene sandstone, siltstone, tuffaceous siltstone, and conglomerate.  The southern quarter of the quadrangle is underlain principally by deformed Mesoproterozoic sedimentary rocks of the Newland Formation, which are intruded by Eocene biotite hornblende dacite dikes.  In this southern terrane, Tertiary strata are exposed only in a limited area near the southeast margin of the quadrangle.  The distinct terranes are juxtaposed along the Volcano Valley fault zone—a zone of recurrent crustal movement beginning possibly in Mesoproterozoic time and certainly established from Neoproterozoic–Early Cambrian to late Tertiary time.  Movement along the fault zone has included normal faulting, the southern terrane faulted down relative to the northern terrane, some reverse faulting as the southern terrane later moved up against the northern terrane, and lateral movement during which the southern terrane likely moved west relative to the northern terrane.  Near the eastern margin of the quadrangle, the Newland Formation is locally the host of stratabound sulfide mineralization adjacent to the fault zone; west along the fault zone across the remainder of the quadrangle are significant areas and bands of hematite and iron-silicate mineral concentrations related to apparent alteration of iron sulfides.  The map defines the distribution of a variety of surficial deposits, including the distribution of hematite-rich colluvium and iron-silicate boulders.  The southeast

Physicochemical Properties, Micromorphology and Clay Mineralogy of Soils Affected by Geological Formations, Geomorphology and Climate

Directory of Open Access Journals (Sweden)

A. Bayat

2017-01-01

Full Text Available Introduction: Soil genesis and development in arid and semi-arid areas are strongly affected by geological formations and geomorphic surfaces. Various morphological, physical, and geochemical soil properties at different geomorphic positions are usually attributed to different soil forming factors including parent material and climate. Due to variations in climate, geological formations (Quaternary, Neogene and Cretaceous and geomorphology, the aim of the present research was the study of genesis, development, clay mineralogy, and micromorphology of soils affected by climate, geology and geomorphology in Bardsir area, Kerman Province. Materials and Methods: The study area, 25000 ha, starts from Bardsir and extends to Khanesorkh elevations close to Sirjan city. The climate of the area is warm and semi-arid with mean annual temperature and precipitation of 14.9 °C and 199 mm, respectively. Soil moisture and temperature regimes of the area are aridic and mesic due to 1:2500000 map, provided by Soil and Water Research Institute. Moving to west and southwest, soil moisture regime of the area changes to xeric with increasing elevation. Using topography and geology maps (1:100000 together with Google Earth images, geomorphic surfaces and geologic formations of the area were investigated. Mantled pediment (pedons 1, 3, 7, and 8, rock pediment (pedon 2, semi-stable alluvial plain (pedon 6, unstable alluvial plain (pedon 5, piedmont plain (pedons 9 and 11, intermediate surface of alluvial plain and pediment (pedon 4, and old river terrace (pedon 10 are among geomorphic surfaces investigated in the area. Mantled pediment is composed of young Quaternary sediments and Cretaceous marls. Rock pediments are mainly formed by Cretaceous marls. Quaternary formations are dominant in alluvial plains. Alluvial terraces and intermediate surface of alluvial plain and pediment are dominated by Neogene conglomerates. Siltstone, sandstone, and Neogene marls together with

Densities and Kinematic Viscosities for the Systems Benzene + Methyl Formate, Benzene + Ethyl Formate, Benzene + Propyl Formate, and Benzene + Butyl Formate

DEFF Research Database (Denmark)

Emmerling, Uwe; Rasmussen, Peter

1998-01-01

a Redlich-Kister type of expression with temperature-independent parameters and the data for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate with temperature-dependent parameters. The viscosities have furthermore been compared to values predicted by means of the GC......Densities and kinematic viscosities have been measured for the system benzene + methyl formate at 20°C and for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate from 20°C to 50°C. The results for the system benzene + methyl formate have been correlated using...

Mineralogical, chemical, and petrographic analysis of selected rock samples

International Nuclear Information System (INIS)

Roy, D.M.

1976-01-01

I. The majority of rocks examined from the NTS were found to be siltstones, varying from coarse into the very fine siltstone range, and containing > 60% quartz, usually much higher. Samples of the UEIL series of cores, in contrast, had a large clay mineral fraction, as well as some carbonate present. A few were intermediate silty claystones or argillites. Microphotographs are included to illustrate the variations in texture observed, while most of the data obtained are summarized in tabular form. II. Seven Michigan Salina evaporite specimens were analyzed

Sedimentary uranium deposit of the Ipora/Amorinopolis region, state of Goias, Brazil

International Nuclear Information System (INIS)

Fernandes, S.M.; Leonardos, O.H.

1984-01-01

The uranium mineralization is chiefly found within arkosic sandstones at the base of the Devonian Ponta Grossa Formation. The ore is tabular and concordant with the bedding, the controls being simultaneously litho-stratigraphical and biochemical. Narrow permeable horizons of arkosic sandstone lie between impermeable shale and siltstone layers. Within the permeable horizon, the fossil remains (probably brachiopods) are replaced by uranium minerals. The oxidized iron minerals may have acted as to insulate and preserve the secondary soluble uranium minerals. The mineral paragenesis is represented by renardite, meta - autunite I, fourmarierite, Koninckite, ranquilite, meta-uranocircite II, barite, apatite, calophane, wavelite, varscite, an unnamed uranium mineral, quartz, calcedony, goethite, lepidocrocite and hematite. (Author) [pt

Petrographic and geochemical characterization and isotope analysis of U-PB (SHRIMP) in tuffaceous siltstone, Salitre formation, Sao Francisco supergroup, BA, Brazil; Caracterizacao petrografica, geoquimica e analises isotopicas U-PB (SRIMP) em siltito tufaceo, formacao Salitre Supergrupo Sao Francisco, Bahia

Energy Technology Data Exchange (ETDEWEB)

Santana, Ana; Chemale Junior, Farid, E-mail: ana.santana.geo@gmail.com [Universidade de Brasilia (UnB), DF (Brazil); Sherer, Claiton Marlon dos Santos [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil)

2015-07-01

The Salitre Formation consists of neoproterozoic carbonate sequence overlying the Sao Francisco Craton (SFC) in Bahia. Data on the origin of such training are scarce, mainly due to their nature, essentially carbonate. In this study, from the petrographic characterization and geochemical thin levels of terrigenous, it was identified the contribution of volcanic material. Isotopic analysis of U-Pb, SHRIMP, indicate the existence of young grain, aged 669 ± 14 Ma (Cryogenian) - probable volcanism associated with the building of neoproterozoic mobile belts surrounding the SFC - and inherited zircons with the main population in the Paleoproterozoic and corresponding to the source area of the crystalline basement. Detrital zircons with ages between Statherian and Tonian have also been reported and have the source area the metasedimentary rocks of the Espinhaco Supergroup. (author)

Traces in the dark: sedimentary processes and facies gradients in the upper shale member of the Upper Devonian-Lower Mississippian Bakken Formation, Williston Basin, North Dakota, U.S.A.

Science.gov (United States)

Egenhoff, Sven O.; Fishman, Neil S.

2013-01-01

Black, organic-rich rocks of the upper shale member of the Upper Devonian–Lower Mississippian Bakken Formation, a world-class petroleum source rock in the Williston Basin of the United States and Canada, contain a diverse suite of mudstone lithofacies that were deposited in distinct facies belts. The succession consists of three discrete facies associations (FAs). These comprise: 1) siliceous mudstones; 2) quartz- and carbonate-bearing, laminated mudstones; and 3) macrofossil-debris-bearing massive mudstones. These FAs were deposited in three facies belts that reflect proximal to distal relationships in this mudstone system. The macrofossil-debris-bearing massive mudstones (FA 3) occur in the proximal facies belt and contain erosion surfaces, some with overlying conodont and phosphate–lithoclast lag deposits, mudstones with abundant millimeter-scale siltstone laminae showing irregular lateral thickness changes, and shell debris. In the medial facies belt, quartz- and carbonate-bearing, laminated mudstones dominate, exhibiting sub-millimeter-thick siltstone layers with variable lateral thicknesses and localized mudstone ripples. In the distal siliceous mudstone facies belt, radiolarites, radiolarian-bearing mudstones, and quartz- and carbonate-bearing, laminated mudstones dominate. Overall, total organic carbon (TOC) contents range between about 3 and 10 wt %, with a general proximal to distal decrease in TOC content. Abundant evidence of bioturbation exists in all FAs, and the lithological and TOC variations are paralleled by changes in burrowing style and trace-fossil abundance. While two horizontal traces and two types of fecal strings are recognized in the proximal facies belt, only a single horizontal trace fossil and one type of fecal string characterize mudstones in the distal facies belt. Radiolarites intercalated into the most distal mudstones are devoid of traces and fecal strings. Bedload transport processes, likely caused by storm-induced turbidity

Formate Formation and Formate Conversion in Biological Fuels Production

Directory of Open Access Journals (Sweden)

Bryan R. Crable

2011-01-01

Full Text Available Biomethanation is a mature technology for fuel production. Fourth generation biofuels research will focus on sequestering CO2 and providing carbon-neutral or carbon-negative strategies to cope with dwindling fossil fuel supplies and environmental impact. Formate is an important intermediate in the methanogenic breakdown of complex organic material and serves as an important precursor for biological fuels production in the form of methane, hydrogen, and potentially methanol. Formate is produced by either CoA-dependent cleavage of pyruvate or enzymatic reduction of CO2 in an NADH- or ferredoxin-dependent manner. Formate is consumed through oxidation to CO2 and H2 or can be further reduced via the Wood-Ljungdahl pathway for carbon fixation or industrially for the production of methanol. Here, we review the enzymes involved in the interconversion of formate and discuss potential applications for biofuels production.

The Jurassic of Denmark and Greenland: An offshore transgressive–regressive mudstone-dominated succession from the Sinemurian of Skåne, Sweden

Directory of Open Access Journals (Sweden)

Surlyk, Finn

2003-10-01

Full Text Available A Sinemurian mudstone-dominated succession was exposed until recently in the Gantofta quarry in Skåne, southern Sweden. The deposits are placed in the Döshult and Pankarp Members of the Sinemurian–Aalenian Rya Formation. Similar facies of the same age are widespread in the Danish Basin where they constitute the F-Ib unit (F-I member of the Fjerritslev Formation. The Gantofta succession thus represents the easternmost extension of the environment characteristic of the Fjerritslev Formation and is essentially the only locality where it has been possible tostudy the facies of this formation in outcrop. Sedimentation seems to have taken place under relatively quiet tectonic conditions except for the possible fault-control of the basin margin. Thelower part of the Gantofta section is of Early and early Late Sinemurian age. It represents the upper part of the Döshult Member and consists of muddy, lower shoreface sandstones, abruptlyoverlain by dark, bioturbated, fossiliferous mudstones with thin storm siltstones and sandstones. They are overlain by the Upper Sinemurian Pankarp Member which comprises red-brown, restricted marine calcareous mudstones with an upwards increasing number of storm siltstones and sandstones reflecting general shallowing and shoreline progradation.The succession spans the greater part of two simple sequences with a distal sequence boundary located at the boundary between the Döshult Member and the Pankarp Member. The exposed part of the lower sequence includes a thick transgressive systems tract and a very thin highstand systems tract. The upper sequence is represented by an undifferentiated transgressive and highstand systems tract. An Early Sinemurian sea-level rise, a late Early Sinemurian highstand, an early Late Sinemurian fall and a Late Sinemurian minor rise and a major fall are recognised. Nearby boreholes show evidence for an end-Sinemurian – Early Pliensbachian major rise. This evolution corresponds well with

Use of total organic carbon, spectral gamma ray and bioturbation as tools in the identification of source rock; Carbono organico total, gamaespectrometria e bioturbacao como ferramentas na busca de possiveis horizontes geradores de hidrocarbonetos

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Anderson S.; Pereira, Egberto [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Faculdade de Geologia. Dept. de Estratigrafia e Paleontologia

2008-07-01

This work presents the result obtained for the gamaespectrometric study of a borehole situated in north of Parana Basin, concerning sediments of the Ponta Grossa Formation. The Total Radioactivity data and the concentrations of Potassium (K), Uranium (U), Thorium (Th) have been compared to the Total Organic Carbon (TOC) and to the degree of bioturbation intensity. The mentioned formation is composed of basal sandstones deposited in shoreface conditions, which pass to siltstones and black shales deposited in offshore conditions. Nine sedimentary facies were identified based on sedimentological characteristics and sedimentary structures. The bioturbation intensity indicates the modification degree of the initial arrangement of sedimentary beds by the action of organisms. High TOC values in the intervals in addition to the increase of the radioactivity values indicate anoxic conditions. These conditions are ideal for the organic matter concentration and preservation, reflecting favorable intervals to the hydrocarbons (HC) generation. Thus, with the integrated use of diverse tools it was possible to confirm that the Givetian-Frasnian interval of the Ponta Grossa Formation presents the best potential of HC generation of the section analyzed. (author)

Copper mineralization geology of Mandacaru, State of Piaui, Brazil

International Nuclear Information System (INIS)

Parente, C.V.

1984-01-01

The Mandacaru area, Sao Juliao county, Piaui, comprises a Precambrian crystalline basement of granitic to quartaz dioritic gneisses overlain by several younger units of low grade metamorphics, volcanic and sedimentary rocks. The late Proterozoic Sao Juliao sequence comprises folded epicontinental marine metasediments of rank greenschist facies, including phyllite marble, metarkose and quartzite. The Eopaleozoic Catole Formation is represented by continental volcanic material (basalt, andesitic basalt, dacite, rhyolite, pyroclastics) and sedimentary rocks (conglomerate, arkosic wacke, felspathic sandstone, silt-stone), intruded by the post-tectonic Mandacaru Granite and related dykes and apophyses of granophyre, quartz porphyry, and other felsic subvolcanic roks. The intrusive rocks display subalkaline to slightly alkaline (potassic) trends. Rb-Sr isotope determinations yielded a reference isochron of 550+-8 my, Ri=0,70924+-0,0010. Eopaleozoic volcanism, sedimentation and granite introsion are controlled by faulting and graben-like strucutures, the evolution of which culminated with the deposition of polymictic conglomerate and breccia of the Tamboril Formation. AII the previous units are unconformably overlain by the Silurian Serra Grande Formation at the eastern border of the Parnaiba Basin. (Author) [pt

Radioactivity of rocks from the geological formations belonging to the Tibagi River hydrographic basin; Radioatividade de rochas provenientes das formacoes geologicas pertencentes a bacia hidrografica do Rio Tibagi

Energy Technology Data Exchange (ETDEWEB)

Bastos, Rodrigo Oliveira

2008-07-01

This work is a study of the {sup 40}K and the {sup 238}U and {sup 232}Th series radioactivity in rocks measured with high resolution gamma ray spectrometry. The rocks were taken from the geologic formations in the region of the Tibagi river hydrographic basin. The course of this river cuts through the Paleozoic and Mesozoic stratigraphic sequences of the Parana sedimentary basin. In order to take into account the background radiation attenuation by the samples, a technique was developed that eliminated the need to measure a blank sample. The effects of the radiation's self-attenuation in the sample matrix were taken into account by using a gamma ray direct transmission method. The results for 87 rock samples, taken from 14 distinct formations, and their corresponding radioactivity variations are presented and discussed according to the possible geological processes from which they originated. Among the most discussed results are: an outcrop that profiles shale, limestone and rhythmite in the Irati Formation; a sandstone and siltstone sequence from the Rio do Rasto Formation; and a profile sampled in a coal mine located in the Rio Bonito Formation. The calculations of the rocks' contributions to the outdoor gamma radiation dose rate agree with the values presented by other authors for similar rocks. The highest dose values were obtained from felsic rocks (rhyolite of the Castro group, 129.8 {+-} 3.7 nGy.h{sup -1}, and Cunhaporanga granite, 167 {+-} 37 nGy.h{sup -1}). The other highest values correspond to the shale rocks from the Irati Formation (109 {+-} 16 nGy.h{sup -1}) and the siltic shale rocks from the Ponta Grossa Formation (107.9 {+-} 0.7 nGy.h{sup -1}). The most recent geological formations presented the lowest dose values (e.g. the Botucatu sandstone, 3.3 {+-} 0.6 nGy.h{sup -1}). The average value for sedimentary rocks from seven other formations is equal to 59 {+-} 26 nGy.h{sup -1}. The Rio Bonito Formation presented the highest dose value (334

Influence of heterogeneity on rock strength and stiffness using discrete element method and parallel bond model

Directory of Open Access Journals (Sweden)

Spyridon Liakas

2017-08-01

Full Text Available The particulate discrete element method (DEM can be employed to capture the response of rock, provided that appropriate bonding models are used to cement the particles to each other. Simulations of laboratory tests are important to establish the extent to which those models can capture realistic rock behaviors. Hitherto the focus in such comparison studies has either been on homogeneous specimens or use of two-dimensional (2D models. In situ rock formations are often heterogeneous, thus exploring the ability of this type of models to capture heterogeneous material behavior is important to facilitate their use in design analysis. In situ stress states are basically three-dimensional (3D, and therefore it is important to develop 3D models for this purpose. This paper revisits an earlier experimental study on heterogeneous specimens, of which the relative proportions of weaker material (siltstone and stronger, harder material (sandstone were varied in a controlled manner. Using a 3D DEM model with the parallel bond model, virtual heterogeneous specimens were created. The overall responses in terms of variations in strength and stiffness with different percentages of weaker material (siltstone were shown to agree with the experimental observations. There was also a good qualitative agreement in the failure patterns observed in the experiments and the simulations, suggesting that the DEM data enabled analysis of the initiation of localizations and micro fractures in the specimens.

The sedimentology and mineralogy of the river uranium deposit near Phuthaditjhaba, Qwa-Qwa

International Nuclear Information System (INIS)

Brynard, H.J.; Le Roux, J.P.

1982-08-01

A sedimentological and mineralogical investigation was carried out on the River deposit discovered by Mining Corporation (Pty) Ltd in Qwa-Qwa, 15 km south-west of Phuthaditjhaba. The orebody is located in fluvial sandstones of the upper Elliot Formation. Palaeocurrent directions reflect a low- to very low-sinuosity river system with a vector mean azimuth towards 062 degrees. A study of sedimentary structures and grain sizes in cliff sections was supplemented by an analysis of borehole logs, which disclosed the sedimentary environment as a braided river of the Donjek type. Uranium mineralisation at the River prospect is unusually thick, averaging almost 2 m, but lower overall grade than the southern Karoo deposits. Almost 30% of the uranium is present in mudstone and siltstone, and the fact that mineralisation in the sandstone is of similar grade and thickness to that of the former two lithological types suggests that grain sizes played a minor role in the dispersion of the ore fluids. The rocks are mainly of three types, viz. lithic graaywackes, feldspathic graywackes and siltstones, of which calcareous and carbonaceous varieties of the former two occur. Uranium mineralisation is associated mainly with organic carbon which occurs in various modes. A small amount of uranium is present as secondary beta-uranophane which occurs interstitially to detrital grains and in the pores of the clayey matrix and lithic fragments. Uranium is the only trace element of economic significance

Galaxy formation

International Nuclear Information System (INIS)

Silk, J.; Di Cintio, A.; Dvorkin, I.

2014-01-01

Galaxy formation is at the forefront of observation and theory in cosmology. An improved understanding is essential for improving our knowledge both of the cosmological parameters, of the contents of the universe, and of our origins. In these lectures intended for graduate students, galaxy formation theory is reviewed and confronted with recent observational issues. In lecture 1, the following topics are presented: star formation considerations, including IMF, star formation efficiency and star formation rate, the origin of the galaxy luminosity function, and feedback in dwarf galaxies. In lecture 2, we describe formation of disks and massive spheroids, including the growth of supermassive black holes, negative feedback in spheroids, the AGN-star formation connection, star formation rates at high redshift and the baryon fraction in galaxies.

Influence of the Eastern California Shear Zone on deposition of the Mio-Pliocene Bouse Formation: Insights from the Cibola area, Arizona

Science.gov (United States)

Dorsey, Rebecca J.; O'Connell, Brennan; Homan, Mindy B.; Bennett, Scott E. K.

2017-01-01

The Eastern California Shear Zone (ECSZ) is a wide zone of late Cenozoic strike-slip faults and related diffuse deformation that currently accommodates ~20–25% of relative Pacific–North America plate motion in the lower Colorado River region (Fig. 1A; Dokka and Travis, 1990; Miller et al., 2001; Guest et al., 2007; Mahan et al., 2009). The ECSZ is kinematically linked southward to dextral faults in the northern Gulf of California (Bennett et al., 2016a), and it may have initiated ca. 8 Ma when major strike-slip faults developed in the northern Gulf and Salton Trough region (Bennett et al., 2016b; Darin et al., 2016; Woodburne, 2017). Thus deformation related to the ECSZ occurred in the lower Colorado River region during deposition of the Bouse Formation, which is commonly bracketed between 6.0 and 4.8 Ma (House et al., 2008; Sarna-Wojcicki et al., 2011; Spencer et al., 2013) and may be as old as 6–7 Ma in the south (McDougall and Miranda Martínez, 2014, 2016). Post-4.5 Ma broad sagging is recognized along the lower Colorado River (Howard et al., 2015), but the possibility that faults of the ECSZ influenced local to regional subsidence patterns during deposition of the Bouse Formation has received little attention to date (e.g., Homan, 2014; O’Connell et al., 2016). The Bouse Formation is a widespread sequence of late Miocene to early Pliocene deposits exposed discontinuously along the lower Colorado River corridor (Fig. 1A). In the southern Blythe basin it consists of three regionally correlative members: (1) Basal Carbonate, consisting of supratidal and intertidal mud-flat marls, intertidal and shallow subtidal bioclastic grainstone and conglomerate, and subtidal marl; (2) Siliciclastic member, consisting of Colorado River-derived green claystone, red mudstone and siltstone, and cross-bedded river channel sandstone; and (3) Upper Bioclastic member fossiliferous sandy calcarenite, coarse pebbly grainstone, and calcareous-matrix conglomerate (Homan, 2014

Sequence stratigraphy of Taciba and Rio Bonito formations in Mafra, SC area, eastern Parana Basin, Brazil; Estratigrafia de sequencias das formacoes Taciba e Rio Bonito (Membro Triunfo) na regiao de Mafra/SC, leste da Bacia do Parana

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-05-01

The Taciba and Rio Bonito ('lower' Triunfo Mbr) formations are divided into six depositional sequences based on cores, gamma-ray and electrical logs from shallow drillings from northern Santa Catarina State, Brazil. Each sequence is formed by two systems tracts, a lower one, sandy (low stand) and an upper one, shaly (high stand). The Taciba Formation has three sequences, S{sub 0} to S{sub 2}; sequence S{sub 0} has a thick turbidite sandstone at the base (Rio Segredo Member) that pinches out towards the eastern margin and even disappears in the Mafra outcrop area. Sequence S{sub 1} varies from a thin fluvial-estuarine system to a thick turbidite sandstone of a channelled fan system; S{sub 1} upper shaly system tract is marine in well PP-11, and it is glacially influenced in well PP-10. Sequence S{sub 2} is a thick sandstone body of shallow marine origin, but restricted to one well (PP-11); its upper shaly tract is dominated by massive siltstones intercalated with thin, distal tempestites. The 'lower' Triunfo Member (or 'Taciba- Triunfo transition') begins with the arrival of deltaic clastics of sequence S{sub 3} lower tract, coarsening-up from medial- to proximal delta front sandstones. Sequence S{sub 4} is quite similar to S{sub 3}, both showing sandstone pro gradation from north to south, as opposed to the southwest-sourced transgressive diamictites. Sequence S{sub 5} consists of fluvial deposits at well PP-12, and two transgressive cycles from wells PP-11 to PP-9, each one of them composed of fluvial-estuarine to marine systems. Well PP-10 is an exception, where the lower cycle presents de glaciation to marine deposits. (author)

Depositional Environments of Late Danian Plant Localities: Chubut Provice, Patagonia, Argentina

Science.gov (United States)

Comer, E.; Slingerland, R. L.; Wilf, P.

2010-12-01

Diverse, well-preserved macroflora are observed within Cretaceous and Paleocene sediments of Chubut Province, Patagonia, Argentina. These macroflora are the most well preserved early Paleocene flora from Gondwana and add new insight into the diversity and environments of that epoch. Two major sites of fossil preservation, Palacio de los Loros and Parque Provincial Ormachea, sit near the top of the Late Danian (65.5-61.7 Ma) Salamanca Formation. Understanding the depositional history of the Salamanca is important in characterizing paleoenvironments in which these flora lived and relating these Patagonian macroflora to concurrent Paleocene flora within the Gondwanan supercontinent. During a two week field season, twenty stratigraphic sections were measured along the outcrop belt at Palacio de los Loros and Ormachea Park as well as two minor sites; Las Flores, and Rancho Grande. Photo mosaics, laser ranger data, and stratigraphic columns were merged with elevated geologic maps and imported into Fledermaus to generate a 3-D visualization of facies relationships. Rock samples were also collected and will be thin sectioned and analyzed for petrography and grain size. The Salamanca Fm. consists of 7 facies, listed here in stratigraphically ascending order: 1)Transgressive sands, 2)Wispy-bedded claystone, 3)Banco Verde, 4)White Cross bedded sandstone, 5)Accretion set siltstone, 6)Transitional silty claystone and 7)Banco Negro. Based on these facies, the Salamanca Fm. is interpreted as a marine-shelf to brackish, tide-dominated, estuarine deposit. The base of the Salamanca Fm. rests on an unconformity representing a marine flooding surface and lower sections of the Salamanca, facies 1 and 2, contain abundant glauconite and fossils indicative of a marine shelf environment. These facies give way upwards to bi-directional trough cross bedded sandstones interspersed with flaser bedded sandy siltstones (facies 3 and 4) indicating a less marine estuary with strong flow regimes

Stratigraphy and facies development of the marine Late Devonian near the Boulongour Reservoir, northwest Xinjiang, China

Science.gov (United States)

Suttner, Thomas J.; Kido, Erika; Chen, Xiuqin; Mawson, Ruth; Waters, Johnny A.; Frýda, Jiří; Mathieson, David; Molloy, Peter D.; Pickett, John; Webster, Gary D.; Frýdová, Barbora

2014-02-01

Late Devonian to Early Carboniferous stratigraphic units within the 'Zhulumute' Formation, Hongguleleng Formation (stratotype), 'Hebukehe' Formation and the Heishantou Formation near the Boulongour Reservoir in northwestern Xinjiang are fossil-rich. The Hongguleleng and 'Hebukehe' formations are biostratigraphically well constrained by microfossils from the latest Frasnian linguiformis to mid-Famennian trachytera conodont biozones. The Hongguleleng Formation (96.8 m) is characterized by bioclastic argillaceous limestones and marls (the dominant facies) intercalated with green spiculitic calcareous shales. It yields abundant and highly diverse faunas of bryozoans, brachiopods and crinoids with subordinate solitary rugose corals, ostracods, trilobites, conodonts and other fish teeth. The succeeding 'Hebukehe' Formation (95.7 m) consists of siltstones, mudstones, arenites and intervals of bioclastic limestone (e.g. 'Blastoid Hill') and cherts with radiolarians. A diverse ichnofauna, phacopid trilobites, echinoderms (crinoids and blastoids) together with brachiopods, ostracods, bryozoans and rare cephalopods have been collected from this interval. Analysis of geochemical data, microfacies and especially the distribution of marine organisms, which are not described in detail here, but used for facies analysis, indicate a deepening of the depositional environment at the Boulongour Reservoir section. Results presented here concern mainly the sedimentological and stratigraphical context of the investigated section. Additionally, one Late Devonian palaeo-oceanic and biotic event, the Upper Kellwasser Event is recognized near the section base.

Preliminary chronostratigraphy of the Tetagouche and Fournier groups in northern New Brunswick

International Nuclear Information System (INIS)

Sullivan, R.W.; VanStaal, C.R.

1996-01-01

Seven U-Pb zircon ages of volcanic rocks from northern New Brunswick are reported and a preliminary stratigraphy of the middle Ordovician Tetagouche and Fournier groups is presented. Deposition of the Tetagouche Group started with calcareous rocks of the Vallee Lourdes Formation in the Late Arenig (>470 Ma). Quartz- and feldspar-phyric felsic volcanic rocks of the immediately overlying Nepisiquit Falls Formation yielded U-Pb zircon ages between ca. 471 and 469 Ma. These volcanic rocks are time stratigraphic equivalents of the feldspar-phyric dacites of the Spruce Lake Formation, which yielded a U-Pb zircon age of ca. 470 Ma, and tholeiitic and alkalic pillow basalts of the structurally overlying Canoe Landing Lake Formation. The final phase of rhyolitic to dacitic volcanism is marked by the emplacement of distinct quartz- and feldspar-phyric dacitic porphyries at ca. 465 Ma, thus limiting silicic volcanism to the Late Arenig and llanvim. During the Ilandeilo and Caradoc (ca. 464-457 Ma) volcanic activity in the Tetagouche Group was characterized by extrusion of alkali basalts and minor comendites, interlayered with dark shales and siltstones of the Boucher Brook Formation. Oceanic crust of the Fournier Group was also formed during this period. (author). 29 refs., 1 tab., 10 figs

Preliminary chronostratigraphy of the Tetagouche and Fournier groups in northern New Brunswick

Energy Technology Data Exchange (ETDEWEB)

Sullivan, R W; VanStaal, C R [Geological Survey of Canada, Ottawa, ON (Canada)

1997-12-31

Seven U-Pb zircon ages of volcanic rocks from northern New Brunswick are reported and a preliminary stratigraphy of the middle Ordovician Tetagouche and Fournier groups is presented. Deposition of the Tetagouche Group started with calcareous rocks of the Vallee Lourdes Formation in the Late Arenig (>470 Ma). Quartz- and feldspar-phyric felsic volcanic rocks of the immediately overlying Nepisiquit Falls Formation yielded U-Pb zircon ages between ca. 471 and 469 Ma. These volcanic rocks are time stratigraphic equivalents of the feldspar-phyric dacites of the Spruce Lake Formation, which yielded a U-Pb zircon age of ca. 470 Ma, and tholeiitic and alkalic pillow basalts of the structurally overlying Canoe Landing Lake Formation. The final phase of rhyolitic to dacitic volcanism is marked by the emplacement of distinct quartz- and feldspar-phyric dacitic porphyries at ca. 465 Ma, thus limiting silicic volcanism to the Late Arenig and llanvim. During the Ilandeilo and Caradoc (ca. 464-457 Ma) volcanic activity in the Tetagouche Group was characterized by extrusion of alkali basalts and minor comendites, interlayered with dark shales and siltstones of the Boucher Brook Formation. Oceanic crust of the Fournier Group was also formed during this period. (author). 29 refs., 1 tab., 10 figs.

Stellar formation

CERN Document Server

Reddish, V C

1978-01-01

Stellar Formation brings together knowledge about the formation of stars. In seeking to determine the conditions necessary for star formation, this book examines questions such as how, where, and why stars form, and at what rate and with what properties. This text also considers whether the formation of a star is an accident or an integral part of the physical properties of matter. This book consists of 13 chapters divided into two sections and begins with an overview of theories that explain star formation as well as the state of knowledge of star formation in comparison to stellar structure

Uranium and main oxides in soil in the Northeast part of Parana basil

International Nuclear Information System (INIS)

Fagundes, I.C.; Bonotto, D.M.; Jimenez-Rueda, J.R.

2015-01-01

Uranium is a litophile element that migrates to crust together with other light silicates. This work evaluated the relationships among the concentrations of uranium, major oxides (SiO_2, Al_2O_3, Na_2O, K_2O, CaO, MgO, Fe_2O_3, MnO, TiO_2, P_2O_5) and organic matter in different horizons of a soil profile located over siltstone from Tatui Formation, Piracicaba River sub-basin, Sao Paulo State, Brazil. Different techniques were utilized for data acquisition, for instance, alpha spectrometry, X-ray fluorescence spectrometry and smectrophotometry. The major U concentrations were found in horizons enriched in Fe_2O_3, indicating its tending to be retained in iron oxides. (author)

Exploration of Uranium in Simpang Kanan, East Aceh, Preliminary Prospecting Stages

International Nuclear Information System (INIS)

Djalil, A; Sutriyono, A; Sajiyo

1998-01-01

Exploration of uranium in simpang kanan, east aceh, preliminary prospecting stages. The research has been carried out to obtain the knowledge of geology, radiometry and geochemistry in relation with U prospect development. Based on the similarity of lithology in takengon sector which indicates the existence of uranium mineralization. Research method consist of geological observation, radiometric measurements of outcrops, boulders and stream sediment and heavy mineral samples. Laboratory analysis consist of petrography, autoradiography and uranium content analysis of stream sediment and rock samples. The lithology consist of slate, quartzite, marble, granite, dacite, limestone, carbonaceous sandstone, black claystone, sandstone, siltstone, carbonaceous siltstone. This area found, has been folded with the folding axis direction of NW-SE. Fault structures are generally formed as strike slip fault and several location as normal fault and heavy minerals anomalous was interpreted from granite and sandstone- siltstone. Occurrences of the geochemical anomaly, lithology and geological structures, there has been shown that few location is being the prospect area covered about 70 km of 1800km prospecting area, so it is suggested that in those related prospect area should be performed further observation

Petrology of the Devonian gas-bearing shale along Lake Erie helps explain gas shows

Energy Technology Data Exchange (ETDEWEB)

Broadhead, R.F.; Potter, P.E.

1980-11-01

Comprehensive petrologic study of 136 thin sections of the Ohio Shale along Lake Erie, when combined with detailed stratigraphic study, helps explain the occurrence of its gas shows, most of which occur in the silty, greenish-gray, organic poor Chagrin Shale and Three Lick Bed. Both have thicker siltstone laminae and more siltstone beds than other members of the Ohio Shale and both units also contain more clayshales. The source of the gas in the Chagrin Shale and Three Lick Bed of the Ohio Shale is believed to be the bituminous-rich shales of the middle and lower parts of the underlying Huron Member of the Ohio Shale. Eleven petrographic types were recognized and extended descriptions are provided of the major ones - claystones, clayshales, mudshales, and bituminous shales plus laminated and unlaminated siltstones and very minor marlstones and sandstones. In addition three major types of lamination were identified and studied. Thirty-two shale samples were analyzed for organic carbon, whole rock hydrogen and whole rock nitrogen with a Perkin-Elmer 240 Elemental Analyzer and provided the data base for source rock evaluation of the Ohio Shale.

Satellite formation flying relative dynamics, formation design, fuel optimal maneuvers and formation maintenance

CERN Document Server

Wang, Danwei; Poh, Eng Kee

2017-01-01

This book systematically describes the concepts and principles for multi-satellite relative motion, passive and near passive formation designs, trajectory planning and control for fuel optimal formation maneuvers, and formation flying maintenance control design. As such, it provides a sound foundation for researchers and engineers in this field to develop further theories and pursue their implementations. Though satellite formation flying is widely considered to be a major advance in space technology, there are few systematic treatments of the topic in the literature. Addressing that gap, the book offers a valuable resource for academics, researchers, postgraduate students and practitioners in the field of satellite science and engineering.

Why adult formation

Directory of Open Access Journals (Sweden)

Andrej Justinek

1997-01-01

Full Text Available The article argues that the primary aim of adult formation is comprehensive personality development which is supposed to ensure quality existence in modern world. The article also suggests that formarion is a permanent process. Justinek puts special emphasis on adult formation methodology and defines fundamental formation styles which encourage independent action in individuals. Justinek differentiates between formation and education. methods and concludes that formation methods are related to the emotional sphere of personality, and education methods mostly to the rational. Justinek believes that formation of adults is based primarily on appropriate formation methodology.

Occurrence of tephra/volcanic tuff in the tertiary sediments of Himachal Himalaya from Tileli area, Mandi district, H.P.: implication for stratigraphy and uranium mineralization

International Nuclear Information System (INIS)

Pandey, Pradeep; Chabbra, Jyotsana; Joshi, G.B.; Parihar, P.S.

2014-01-01

Presence of Early Tertiary pyroclastic material (tephra) has been documented petrographically, for the first time, in the Mandi-Bilaspur Sector from Tileli area, Dharamsala basin of Himachal Pradesh. The tephra is reported from the red shale, identified as tuffaceous siltstone belonging to lower Dharamsala Formation that lies above the uraniferous sandstone body and occurs as thin layers of over 300m along the strike, close to the contact of lower and upper Dharamsala formations. The tuffaceous material shows crude but preferred orientation of minerals like biotite, muscovite, chlorite, clay, hematite and specularite. Various features indicating presence of tephra are, glass shards altered to clay but retaining 'U' shaped outline, spindle-shaped hematite with preferred orientation, spherical to sub-spherical clay and altered Fe oxide rich balls, clay groundmass with flow pattern, flaky minerals in association with clast depicting asymmetrical ramp structure. A zone of approximately 300 m length containing tuffaceous material has been established at Tileli overlying the uraniferous sandstone body. Identification of tephra at Tileli has significant implications as it enabled in demarcating the boundary between the upper and lower Dharamsala formations in central part of the basin in Bilaspur-Mandi Sector of HP Himalaya and also in guiding the uranium exploration programme in the lower Dharamsala Formation. (author)

Uranium and main oxides in soil in the Northeast part of Parana basil; Uranio e principais oxidos em solo na porcao nordeste da bacia do Parana, Brazil

Energy Technology Data Exchange (ETDEWEB)

Fagundes, I.C.; Bonotto, D.M.; Jimenez-Rueda, J.R., E-mail: fagundes.isabella@gmail.com, E-mail: dbonotto@rc.unesp.br, E-mail: jairorjr@rc.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Paulo, SP (Brazil)

2015-07-01

Uranium is a litophile element that migrates to crust together with other light silicates. This work evaluated the relationships among the concentrations of uranium, major oxides (SiO{sub 2}, Al{sub 2}O{sub 3}, Na{sub 2}O, K{sub 2}O, CaO, MgO, Fe{sub 2}O{sub 3}, MnO, TiO{sub 2}, P{sub 2}O{sub 5}) and organic matter in different horizons of a soil profile located over siltstone from Tatui Formation, Piracicaba River sub-basin, Sao Paulo State, Brazil. Different techniques were utilized for data acquisition, for instance, alpha spectrometry, X-ray fluorescence spectrometry and smectrophotometry. The major U concentrations were found in horizons enriched in Fe{sub 2}O{sub 3}, indicating its tending to be retained in iron oxides. (author)

Evaluation of the Cerro Solo nuclear ore, province of Chubut. Geological characteristics of the deposit and of the basin. Pt. 2

International Nuclear Information System (INIS)

Benitez, A.F.; Fuente, A.; Maloberti, A.; Landi, V.A.; Bianchi, R.E.; Marveggio de Bianchi, N.; Gayone, M.R.

1993-01-01

The Cerro Solo uranium ore deposit, is located 420 km west from Trelew city, Chubut province, in the extra-andean. The geologic environment belongs to the northwest edge portion of the intracratonic San Jorge Gulf Basin. The uraniferous district is named Pichinanes Ridge district. The mineralization lies 25 to 130 m depth, and is hosted by Los Adobes formation aged Aptian-Albian, made up by conglomerates, sandstones, coarse-sandstones and less abundant siltstones and claystones. The Cerro Solo ore deposit that belongs to the sandstone type-uranium occurrences are lenticular or tabular shaped, associated with organic material and pyrite, generally roughly parallel to the bedding (Trend-Type). The uranium minerals are uraninite and coffinite associated with organic material and pyrite, and frequently hematite, goethite, calcite, siderite and barite are observed. (Author)

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African Journals Online (AJOL)

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2 (2016). SEDIMENTOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF OUTCROP. SEDIMENTS OF ... Idowu (2012) and Nton and Okunade (2013). These studies ... and white sandstones, shale, siltstone, claystone, coaly units and ...

Sequence stratigraphy in a mixed carbonate-silicilastic depositional system (Middle Miocene; Styrian Basin, Austria)

Science.gov (United States)

Friebe, J. Georg

1993-07-01

The mixed carbonate-siliciclastic Weißenegg (Allo-) Formation records three depositional sequences corresponding approximately to the TB 2.3, TB 2.4 and TB 2.5 global cycles. Sea-level fluctuations were of the order of at least 30 m. Siliciclastic lowstand systems tracts comprise lignite deposits, reworked basement and tidal siltstones (above a tectonically enhanced sequence boundary) as well as coastal sand bars. Coastal sands of the transgressive systems tract contain distinct layers of well cemented nodules. They are interpreted as the first stage in hardground formation and record superimposed minor sea-level fluctuations. Coral patch reefs and rhodolith platforms developed during transgressive phases and were subsequently drowned and/or suffocated by siliciclastics during early highstand. Shallowing upwards siliciclastic parasequences, each terminated by a bank of rhodolith limestone, form the (late) highstand systems tract. The limestone beds record superimposed fourth-order transgressive pulses. Occasionally a carbonate highstand wedge developed. Lowstand carbonate shedding occurred where the top of a platform which suffered incipient drowning during highstand was near sealevel again during the following lowstand. Late highstand delta progradation is common.

Geologic characterization report for the Paradox Basin Study Region, Utah Study Areas. Volume 6. Salt Valley

International Nuclear Information System (INIS)

1984-12-01

Surface landforms in the Salt Valley Area are generally a function of the Salt Valley anticline and are characterized by parallel and subparallel cuestaform ridges and hogbacks and flat valley floors. The most prominent structure in the Area is the Salt Valley anticline. Erosion resulting from the Tertiary uplift of the Colorado Plateau led to salt dissolution and subsequent collapse along the crest of the anticline. Continued erosion removed the collapse material, forming an axial valley along the crest of the anticline. Paleozoic rocks beneath the salt bearing Paradox Formation consist of limestone, dolomite, sandstone, siltstone and shale. The salt beds of the Paradox Formation occur in distinct cycles separated by an interbed sequence of anhydrite, carbonate, and clastic rocks. The Paradox Formation is overlain by Pennsylvanian limestone; Permian sandstone; and Mesozoic sandstone, mudstone, conglomerate and shale. No earthquakes have been reported in the Area during the period of the historic record and contemporary seismicity appears to be diffusely distributed, of low level and small magnitude. The upper unit includes the Permian strata and upper Honaker Trail Formation. The current data base is insufficient to estimate ground-water flow rates and directions in this unit. The middle unit includes the evaporites in the Paradox Formation and no laterally extensive flow systems are apparent. The lower unit consists of the rocks below the Paradox Formation where permeabilities vary widely, and the apparent flow direction is toward the west. 108 refs., 39 figs., 9 tabs

Formation Design Strategy for SCOPE High-Elliptic Formation Flying Mission

Science.gov (United States)

Tsuda, Yuichi

2007-01-01

The new formation design strategy using simulated annealing (SA) optimization is presented. The SA algorithm is useful to survey a whole solution space of optimum formation, taking into account realistic constraints composed of continuous and discrete functions. It is revealed that this method is not only applicable for circular orbit, but also for high-elliptic orbit formation flying. The developed algorithm is first tested with a simple cart-wheel motion example, and then applied to the formation design for SCOPE. SCOPE is the next generation geomagnetotail observation mission planned in JAXA, utilizing a formation flying techonology in a high elliptic orbit. A distinctive and useful heuristics is found by investigating SA results, showing the effectiveness of the proposed design process.

comparison of authigenic minerals in sandstones and interbedded

African Journals Online (AJOL)

a

Mechanically compacted mudstones, siltstones and shales expelled large ... quartz, and (16) hydrocarbon migration; pyrite and apatite precipitation [1, 7, 12]. ... relationship of the authigenic minerals, burial history and fluid inclusions studies.

Regional paleohydrologic and paleoclimatic settings of wetland/lacustrine depositional systems in the Morrison Formation (Upper Jurassic), Western Interior, USA

Science.gov (United States)

Dunagan, S.P.; Turner, C.E.

2004-01-01

During deposition of the Upper Jurassic Morrison Formation, water that originated as precipitation in uplands to the west of the Western Interior depositional basin infiltrated regional aquifers that underlay the basin. This regional groundwater system delivered water into the otherwise dry continental interior basin where it discharged to form two major wetland/lacustrine successions. A freshwater carbonate wetland/lacustrine succession formed in the distal reaches of the basin, where regional groundwater discharged into the Denver-Julesburg Basin, which was a smaller structural basin within the more extensive Western Interior depositional basin. An alkaline-saline wetland/lacustrine complex (Lake T'oo'dichi') formed farther upstream, where shallower aquifers discharged into the San Juan/Paradox Basin, which was another small structural basin in the Western Interior depositional basin. These were both wetlands in the sense that groundwater was the major source of water. Input from surface and meteoric water was limited. In both basins, lacustrine conditions developed during episodes of increased input of surface water. Inclusion of wetlands in our interpretation of what had previously been considered largely lacustrine systems has important implications for paleohydrology and paleoclimatology. The distal carbonate wetland/lacustrine deposits are well developed in the Morrison Formation of east-central Colorado, occupying a stratigraphic interval that is equivalent to the "lower" Morrison but extends into the "upper" Morrison Formation. Sedimentologic, paleontologic, and isotopic evidence indicate that regional groundwater discharge maintained shallow, hydrologically open, well oxygenated, perennial carbonate wetlands and lakes despite the semi-arid climate. Wetland deposits include charophyte-rich wackestone and green mudstone. Lacustrine episodes, in which surface water input was significant, were times of carbonate and siliciclastic deposition in scarce deltaic

Lava and Life: New investigations into the Carson Volcanics, lower Kimberley Basin, north Western Australia

Science.gov (United States)

Orth, Karin; Phillips, Chris; Hollis, Julie

2014-05-01

The Carson Volcanics are the only volcanic unit in the Paleoproterozoic Kimberley Basin and are part of a poorly studied Large Igneous Province (LIP) that was active at 1790 Ma. New work focussing on this LIP in 2012 and 2013 involved helicopter-supported traverses and sampling of the Carson Volcanics in remote areas near Kalumburu in far north Western Australia's Kimberley region. The succession is widespread and flat lying to gently dipping. It consists of three to six basalt units with intercalated sandstone and siltstone. The basalts are 20-40 m thick, but can be traced up to 60 km along strike. The basalt can be massive or amygdaloidal and commonly display polygonal to subhorizontal and rare vertical columnar jointing. Features of the basalt include ropy lava tops and basal pipe vesicles consistent with pahoehoe lavas. The intercalated cross-bedded quartzofeldspathic sandstone and siltstone vary in thickness up to 40 m and can be traced up to 40 km along strike. Peperite is common and indicates interaction between wet, unconsolidated sediment and hot lava. Stromatolitic chert at the top of the formation represents the oldest life found within the Kimberley region. Mud cracks evident in the sedimentary rocks, and stromatolites suggest an emergent broad tidal flat environment. The volcanics were extruded onto a wide marginal margin setting subject to frequent flooding events. Thickening of the volcanic succession south and the palaeocurrents in the underlying King Leopold Sandstone and the overlying Warton Sandstone suggest that this shelf sloped to the south. The type of basalt and the basalt morphology indicate a low slope gradient of about 1°.

Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

Energy Technology Data Exchange (ETDEWEB)

Andrew G. Cole; George B. Asquith; Jose I. Guzman; Mark D. Barton; Mohammad A. Malik; Shirley P. Dutton; Sigrid J. Clift

1998-04-01

The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based enhanced oil recovery. The study focused on the Ford Geraldine unit, which produces from the upper Bell Canyon Formation (Ramsey sandstone). Reservoirs in this and other Delaware Mountain Group fields have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Outcrop analogs were studied to better interpret the depositional processes that formed the reservoirs at the Ford Geraldine unit and to determine the dimensions of reservoir sandstone bodies. Facies relationships and bedding architecture within a single genetic unit exposed in outcrop in Culberson County, Texas, suggest that the sandstones were deposited in a system of channels and levees with attached lobes that initially prograded basinward, aggraded, and then turned around and stepped back toward the shelf. Channel sandstones are 10 to 60 ft thick and 300 to 3,000 ft wide. The flanking levees have a wedge-shaped geometry and are composed of interbedded sandstone and siltstone; thickness varies from 3 to 20 ft and length from several hundred to several thousands of feet. The lobe sandstones are broad lens-shaped bodies; thicknesses range up to 30 ft with aspect ratios (width/thickness) of 100 to 10,000. Lobe sandstones may be interstratified with laminated siltstones.

Geology of the upper part of the Fort Union Group (Paleocene), Williston Basin, with reference to uranium

International Nuclear Information System (INIS)

Jacob, A.F.

1976-01-01

Tabular sandstone beds in the Sentinel Butte Formation are thicker (as much as 30 m thick), more laterally extensive (more than 2 km wide in many places), and more abundant than in the Tongue River Formation. This indicates that high-sinuosity streams were more abundant where the Sentinel Butte Formation was deposited, and the streams were deeper and occupied wider meander belts, as would be found on the landward part of the delta plain. Siltstone, claystone, lignite, and a small amount of limestone were deposited on natural levees, crevasse splays, and in flood basins. The vertical arrangement of the two formations indicates a progradation of a large deltaic complex into the sea in which the Cannonball Formation was deposited. Sandstone in the Tongue River Formation classifies mostly as carbonate litharenite, and the fine fraction of the formation consists mostly of mica-group minerals, some kaolinite-group minerals, and a little montmorillonite. Sandstone in the Sentinel Butte Formation classifies mostly as volcanic litharenite, and the fine fraction consists mostly of montmorillonite, some kaolinite-group minerals, and a little of the mica-group minerals. The highest-grade uranium deposits in North Dakota are in the Sentinel Butte Formation in the area of the Little Missouri River escarpment in eastern Billings and northwestern Stark Counties. Little uranium has been found in the Tongue River Formation. Uranium may be more abundant in the Sentinel Butte Formation because of the abundance of glassy volcanic matter, which has now been largely altered to montmorillonite, and the abundance of fragments of volcanic rock. Weathering of the upper part of the Sentinel Butte Formation during formation of the Eocene paleosol in the northern Great Plains may have mobilized uranium that was deposited in the formation below the paleosol before deposition of the overlying Oligocene and younger sediment

Rates of star formation

International Nuclear Information System (INIS)

Larson, R.B.

1977-01-01

It is illustrated that a theoretical understanding of the formation and evolution of galaxies depends on an understanding of star formation, and especially of the factors influencing the rate of star formation. Some of the theoretical problems of star formation in galaxies, some approaches that have been considered in models of galaxy evolution, and some possible observational tests that may help to clarify which processes or models are most relevant are reviewed. The material is presented under the following headings: power-law models for star formation, star formation processes (conditions required, ways of achieving these conditions), observational indications and tests, and measures of star formation rates in galaxies. 49 references

Exploring Opponent Formats

DEFF Research Database (Denmark)

Jensen, Mads Møller; Rasmussen, Majken; Grønbæk, Kaj

2013-01-01

of how the opponent format and relationships impact a game are almost absent in current research. Thus, this paper aims to elucidate how the perception of a competition differs, depending on the opponent format, by presenting a game mechanic framework. The paper furthermore presents an interactive...... football-training platform, as well as games designed to explore the different opponent formats. The games are qualitatively evaluated to illuminate the qualities of and distinctions between different types of opponent formats, proposed by the framework terminology....

ENDF/B format

International Nuclear Information System (INIS)

Khalil, M.A.; Lemmel, H.D.

1986-09-01

This document is a brief user's description of the format of ENDF/B. This format, originally designed for the US Evaluated Nuclear Data File, is recommended for international use. This summary is an aid to customers of the IAEA Nuclear Data Section when receiving data retrievals in ENDF/B format. For more detailed information the report BNL-NCS-50496 (ENDF 102) should be consulted. An Appendix to the present document gives a summary of the format differences between ENDF/B-4 and ENDF/B-5. (author)

The Gas-Phase Formation of Methyl Formate in Hot Molecular Cores

Science.gov (United States)

Horn, Anne; Møllendal, Harald; Sekiguchi, Osamu; Uggerud, Einar; Roberts, Helen; Herbst, Eric; Viggiano, A. A.; Fridgen, Travis D.

2004-08-01

Methyl formate, HCOOCH3, is a well-known interstellar molecule prominent in the spectra of hot molecular cores. The current view of its formation is that it occurs in the gas phase from precursor methanol, which is synthesized on the surfaces of grain mantles during a previous colder era and evaporates while temperatures increase during the process of high-mass star formation. The specific reaction sequence thought to form methyl formate, the ion-molecule reaction between protonated methanol and formaldehyde followed by dissociative recombination of the protonated ion [HCO(H)OCH3]+, has not been studied in detail in the laboratory. We present here the results of both a quantum chemical study of the ion-molecule reaction between [CH3OH2]+ and H2CO as well as new experimental work on the system. In addition, we report theoretical and experimental studies for a variety of other possible gas-phase reactions leading to ion precursors of methyl formate. The studied chemical processes leading to methyl formate are included in a chemical model of hot cores. Our results show that none of these gas-phase processes produces enough methyl formate to explain its observed abundance.

The Upper Jurassic Stanleyville Group of the eastern Congo Basin: An example of perennial lacustrine system

Science.gov (United States)

Caillaud, Alexis; Blanpied, Christian; Delvaux, Damien

2017-08-01

The intracratonic Congo Basin, located in the Democratic Republic of Congo (DRC), is the largest sedimentary basin of Africa. The Jurassic strata outcrop along its eastern margin, south of Kisangani (formerly Stanleyville). In the last century, the Upper Jurassic Stanleyville Group was described as a lacustrine series containing a thin basal marine limestone designed as the ;Lime Fine; beds. Since the proposal of this early model, the depositional environment of the Stanleyville Group, and especially the possible marine incursion, has been debated, but without re-examining the existing cores, outcrop samples and historical fossils from the type location near Kisangani that are available at the Royal Museum for Central Africa (MRAC/KMMA, Tervuren, Belgium). In order to refine the former sedimentology, a series of nine exploration cores drilled in the Kisangani sub-basin have been described. This study aims at integrating sedimentary facies in existing sedimentary models and to discuss the hypothesis of the presence of Kimmeridgian marine deposits along the Congo River near Kisangani, a region which lies in the middle of the African continent. Eight facies have been identified, which permit a reinterpretation of the depositional environment and paleogeography of the Stanleyville Group. The base of the Stanleyville Group is interpreted to represent a conglomeratic fluvial succession, which filled an inherited Triassic paleotopography. Above these conglomerates, a transition to a typically lacustrine system is interpreted, which includes: (1) a basal profundal, sublittoral (brown to dark fine-grained siltstones with microbial carbonates, i.e., the ;Lime Fine; beds) and littoral lacustrine series; covered by (2) a sublittoral to profundal interval (brown to dark organic-rich, fine-grained siltstones), which corresponds to the maximum extent of the paleo-lake; and, finally (3) a shallow lacustrine series (greenish calcareous siltstones and sandstones with red siltstones

Compositional variation of glauconites in Upper Cretaceous-Paleogene sedimentary iron-ore deposits in South-eastern Western Siberia

Science.gov (United States)

Rudmin, Maxim; Banerjee, Santanu; Mazurov, Aleksey

2017-06-01

Glauconite occurs either as unaltered greenish or as altered brownish variety in Upper Cretaceous-Palaeocene sediments in the southeastern corner of Western Siberia. Studied section within the Bakchar iron-ore deposit includes Ipatovo, Slavgorod, Gan'kino and Lyulinvor formations, which are represented by sandstones, siltstones, claystones and oolitic ironstones of coastal-marine facies. The origin of unaltered glauconite is explained by the ;verdissement theory;. Transgressions during Lower Coniacian, Santonian and Campanian favored the formation of unaltered glauconites in dysoxic to anoxic conditions. Subaerial exposure of glauconite resulted in leaching of potassium, oxidation of iron and formation of iron hydroxides in Upper Coniacian, Maastrichtian and Palaeocene. Glauconite ultimately converts to leptochlorite and hydrogoethite by this alteration. Abundant microscopic gold inclusions, besides sulphides, sulphates, oxides and silicates characterize this glauconite. Mineral inclusions include precious, rare metals and non-ferrous metals. The concentration of gold in glauconite may be as high as 42.9 ppb. Abundant inclusions of various compositions in glauconites indicate enrichment of marine sediments in precious and non-precious metals. While major element composition of glauconites is affected by subaerial exposure, the broadly similar micro-inclusions in both altered and unaltered varieties are possibly related to the comparatively immobile nature of REE and trace elements.

Alteration of uraniferous and native copper concretions in the Permian mudrocks of south Devon, United Kingdom

Energy Technology Data Exchange (ETDEWEB)

Milodowski, A.E.; Styles, M.T.; Horstwood, M.S.A.; Kemp, S.J. [British Geological Survey, Nottingham (United Kingdom)

2002-03-01

This report presents the results of a study of the mineralogy and alteration characteristics of unusual concretions containing sheets of native copper, and uranium-vanadium mineralised concretions, in mudstones and siltstones of the Pennian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The main objectives of the study were: 1. To investigate the corrosion characteristics of the native copper as a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of spent fuel and high-level radioactive waste (HLW). This study developed from an earlier pilot study, which demonstrated that the alteration of the native copper in the concretions from Littleham Cove was mineralogically and chemically complex. 2. To investigate the alteration and oxidation of minerals containing reduced species (e.g. ferrous iron) within the uranium-rich concretions as a natural analogue for the potential effects of oxidation induced by alpha-radiolysis of water in a HLW repository environment. Native copper-bearing concretions in the Littleham Mudstone Formation are very rare. They occur, as thin lenticular disks developed largely along bedding lamina and thin low-angle fractures cutting the bedding laminae the upper part of the formation, about 10 m below the top of the formation. This part of the sequence comprises laterally discontinuous, fine-grained sheet-flood and channel sandstones and siltstones. Some of these sandstones, are more extensively-cemented by copper sulphides (mainly chalcocite), copper arsenides, cobalt-nickel arsenides, and uranium silicate. The thin permeable sandstones and siltstones, and fractures zones around small faults appear to have acted as the conduits for the movement of mineralising fluids through the mudstones. The native copper sheets all show a similar pattern of corrosion and alteration. However, the intensity of alteration is

Free-format RPG IV the express guide to learning free format

CERN Document Server

Martin, Jim

2015-01-01

Focusing strictly on teaching free-format RPG programming methods, this book will help programmers wishing to upgrade their skills   This how-to guide offers a concise and thorough introduction to the increased productivity, better readability, and easier program maintenance that comes with the free-format style of programming in RPG IV. Although free-format information is available in IBM manuals, it is not separated from everything else, requiring hours of tedious research to track down the information needed. This book provides everything you need to know to write RPG IV in the free-format

Cyclicity and reservoir properties of Lower-Middle Miocene sediments of South Kirinsk oil and gas field

Science.gov (United States)

Kurdina, Nadezhda

2017-04-01

Exploration and additional exploration of oil and gas fields, connected with lithological traps, include the spreading forecast of sedimentary bodies with reservoir and seal properties. Genetic identification and forecast of geological bodies are possible in case of large-scale studies, based on the study of cyclicity, structural and textural features of rocks, their composition, lithofacies and depositional environments. Porosity and permeability evaluation of different reservoir groups is also an important part. Such studies have been successfully completed for productive terrigenous Dagi sediments (Lower-Middle Miocene) of the north-eastern shelf of Sakhalin. In order to identify distribution of Dagi reservoirs with different properties in section, core material of the one well of South Kirinsk field has been studied (depth interval from 2902,4 to 2810,5 m). Productive Dagi deposits are represented by gray-colored sandstones with subordinate siltstones and claystones (total thickness 90,5 m). Analysis of cyclicity is based on the concepts of Vassoevich (1977), who considered cycles as geological body, which is the physical result of processes that took place during the sedimentation cycle. Well section was divided into I-X units with different composition and set of genetic features due to layered core description and elementary cyclites identification. According to description of thin sections and results of cylindrical samples porosity and permeability studies five groups of reservoirs were determined. There are coarse-grained and fine-coarse-grained sandstones, fine-grained sandstones, fine-grained silty sandstones, sandy siltstones and siltstones. It was found, in Dagi section there is interval of fine-coarse-grained and coarse-grained sandstones with high petrophysical properties: permeability 3000 mD, porosity more than 25%, but rocks with such properties spread locally and their total thickness is 6 meters only. This interval was described in the IV unit

Digital Forensics Formats: Seeking a Digital Preservation Storage Container Format for Web Archiving

Directory of Open Access Journals (Sweden)

Yunhyong Kim

2012-12-01

Full Text Available In this paper we discuss archival storage container formats from the point of view of digital curation and preservation, an aspect of preservation overlooked by most other studies. Considering established approaches to data management as our jumping off point, we selected seven container format attributes that are core to the long term accessibility of digital materials. We have labeled these core preservation attributes. These attributes are then used as evaluation criteria to compare storage container formats belonging to five common categories: formats for archiving selected content (e.g. tar, WARC, disk image formats that capture data for recovery or installation (partimage, dd raw image, these two types combined with a selected compression algorithm (e.g. tar+gzip, formats that combine packing and compression (e.g. 7-zip, and forensic file formats for data analysis in criminal investigations (e.g. aff – Advanced Forensic File format. We present a general discussion of the storage container format landscape in terms of the attributes we discuss, and make a direct comparison between the three most promising archival formats: tar, WARC, and aff. We conclude by suggesting the next steps to take the research forward and to validate the observations we have made.

Connecting the Cosmic Star Formation Rate with the Local Star Formation

Science.gov (United States)

Gribel, Carolina; Miranda, Oswaldo D.; Williams Vilas-Boas, José

2017-11-01

We present a model that unifies the cosmic star formation rate (CSFR), obtained through the hierarchical structure formation scenario, with the (Galactic) local star formation rate (SFR). It is possible to use the SFR to generate a CSFR mapping through the density probability distribution functions commonly used to study the role of turbulence in the star-forming regions of the Galaxy. We obtain a consistent mapping from redshift z˜ 20 up to the present (z = 0). Our results show that the turbulence exhibits a dual character, providing high values for the star formation efficiency ( ˜ 0.32) in the redshift interval z˜ 3.5{--}20 and reducing its value to =0.021 at z = 0. The value of the Mach number ({{ M }}{crit}), from which rapidly decreases, is dependent on both the polytropic index (Γ) and the minimum density contrast of the gas. We also derive Larson’s first law associated with the velocity dispersion ( ) in the local star formation regions. Our model shows good agreement with Larson’s law in the ˜ 10{--}50 {pc} range, providing typical temperatures {T}0˜ 10{--}80 {{K}} for the gas associated with star formation. As a consequence, dark matter halos of great mass could contain a number of halos of much smaller mass, and be able to form structures similar to globular clusters. Thus, Larson’s law emerges as a result of the very formation of large-scale structures, which in turn would allow the formation of galactic systems, including our Galaxy.

Formative assessment : Enriching teaching and learning with formative assesment

NARCIS (Netherlands)

van Diggelen, M.R.; Morgan, C.M.; Funk, M.; Bruns, M.

2016-01-01

Formative assessment is a valuable aspect in teaching and learning, and is proven to be an e ective learning method. There is evidence that adding formative assessment to your teaching increases students’ learning results (Black and William, 1998), but in practice many of the possibilities are left

The Bakken - An Unconventional Petroleum and Reservoir System

Energy Technology Data Exchange (ETDEWEB)

Sarg, J.

2011-12-31

An integrated geologic and geophysical study of the Bakken Petroleum System, in the Williston basin of North Dakota and Montana indicates that: (1) dolomite is needed for good reservoir performance in the Middle Bakken; (2) regional and local fractures play a significant role in enhancing permeability and well production, and it is important to recognize both because local fractures will dominate in on-structure locations; and (3) the organic-rich Bakken shale serves as both a source and reservoir rock. The Middle Bakken Member of the Bakken Formation is the target for horizontal drilling. The mineralogy across all the Middle Bakken lithofacies is very similar and is dominated by dolomite, calcite, and quartz. This Member is comprised of six lithofacies: (A) muddy lime wackestone, (B) bioturbated, argillaceous, calcareous, very fine-grained siltstone/sandstone, (C) planar to symmetrically ripple to undulose laminated, shaly, very fine-grained siltstone/sandstone, (D) contorted to massive fine-grained sandstone, to low angle, planar cross-laminated sandstone with thin discontinuous shale laminations, (E) finely inter-laminated, bioturbated, dolomitic mudstone and dolomitic siltstone/sandstone to calcitic, whole fossil, dolomitic lime wackestone, and (F) bioturbated, shaly, dolomitic siltstone. Lithofacies B, C, D, and E can all be reservoirs, if quartz and dolomite-rich (facies D) or dolomitized (facies B, C, E). Porosity averages 4-8%, permeability averages 0.001-0.01 mD or less. Dolomitic facies porosity is intercrystalline and tends to be greater than 6%. Permeability may reach values of 0.15 mD or greater. This appears to be a determinant of high productive wells in Elm Coulee, Parshall, and Sanish fields. Lithofacies G is organic-rich, pyritic brown/black mudstone and comprises the Bakken shales. These shales are siliceous, which increases brittleness and enhances fracture potential. Mechanical properties of the Bakken reveal that the shales have similar

THE SPECIAL STATUS OF EXOGENOUS WORD-FORMATION WITHIN THE GERMAN WORD-FORMATION SYSTEM

Directory of Open Access Journals (Sweden)

Zhilyuk Sergey Aleksandrovich

2014-06-01

Full Text Available The article presents the properties of exogenous word-formation system taking into account the existence of two word-formation systems in modern German. On the basis of foreign research which reveal modern trends in German word-formation connected with the internationalization and the development of new European Latin language. The author defines key features of exogenous word-formation, i.e. foreign origin of wordformation units, unmotivated units, unmotivated interchange in base and affixes as well as limited distribution rules in combination with German word-formation. The article analyzes various approaches to word-division, as well as motivated and unmotivated interchange of consonants in bases and in affixes. Unmotivated interchange showcases a special status of the exogenous word-formation within German. Another item covered by the article is the issue of confix. The article has opinions of researchers about correctness of its separation and a list of its features. The author presents his definition of confix: a confix is a bound exogenous word-formation unit with a certain lexical and semantic meaning and joining other units directly or indirectly (through linking morpheme -o-, which is able to make a base. Moreover, some confixes are able to participate at word-combination and have unlimited distribution. So far, confix showcases the integration of exogenous word-formation and traditional German word-formation. The research proves the special status of exogenous word-formation in German. Its results can be used as a base for further analysis of co-existing word-formation systems in German and determination of their characteristic features.

Comet formation

Science.gov (United States)

Blum, J.

2014-07-01

There has been vast progress in our understanding of planetesimal formation over the past decades, owing to a number of laboratory experiments as well as to refined models of dust and ice agglomeration in protoplanetary disks. Coagulation rapidly forms cm-sized ''pebbles'' by direct sticking in collisions at low velocities (Güttler et al. 2010; Zsom et al. 2010). For the further growth, two model approaches are currently being discussed: (1) Local concentration of pebbles in nebular instabilities until gravitational instability occurs (Johansen et al. 2007). (2) A competition between fragmentation and mass transfer in collisions among the dusty bodies, in which a few ''lucky winners'' make it to planetesimal sizes (Windmark et al. 2012a,b; Garaud et al. 2013). Predictions of the physical properties of the resulting bodies in both models allow a distinction of the two formation scenarios of planetesimals. In particular, the tensile strength (i.e, the inner cohesion) of the planetesimals differ widely between the two models (Skorov & Blum 2012; Blum et al. 2014). While model (1) predicts tensile strengths on the order of ˜ 1 Pa, model (2) results in rather compactified dusty bodies with tensile strengths in the kPa regime. If comets are km-sized survivors of the planetesimal-formation era, they should in principle hold the secret of their formation process. Water ice is the prime volatile responsible for the activity of comets. Thermophysical models of the heat and mass transport close to the comet-nucleus surface predict water-ice sublimation temperatures that relate to maximum sublimation pressures well below the kPa regime predicted for formation scenario (2). Model (1), however, is in agreement with the observed dust and gas activity of comets. Thus, a formation scenario for cometesimals involving gravitational instability is favored (Blum et al. 2014).

Geology of the Golden Gate Highlands National Park

Directory of Open Access Journals (Sweden)

G.H. Groenewald

1986-11-01

Full Text Available The Golden Gate Highlands National Park is underlain by stratigraphic units belonging to the upper part of the Karoo Sequence. These units include part of the Beaufort Group and the Molteno, Elliot, Clarens and Drakensberg Formations. Dolerite dykes and sills are intruded into the succession while recent alluvium and scree cover the valley floors and mountain slopes. The Beaufort Group is represented by red mudstone and light brown fine-grained feldspathic sandstone of the Tarkastad Subgroup. The Molteno Formation consists of medium- to coarse-grained trough cross-bedded sandstone, while the Elliot Formation comprises a thick succession of red mudstone, siltstone and interlayered fine- to medium-grained, light yellow-brown sandstone. The most characteristic feature of the park is the yellowish sandstone cliffs of the Clarens Formation. Cave formation is caused by exudation, differential weathering due to different degrees of carbonate cementation and undercutting of the sandstone. The highest peaks are capped by numerous layers of amygdaloidal and massive varieties of basaltic lava of the Drakensberg Formation. A possible volcanic pipe occurs in the eastern part of the park. The Elliot and Clarens Formations are rich in vertebrate fossil remains, especially Massospondylus sp. Remains of Notochampsa sp., Pachygenelus monus, Clarencea gracilis, Lanasaurus scalpridens and a cluster of unidentified dinosaur eggs have also been found. The formations underlying the Golden Gate Highlands National Park were formed during the Late Triassic Epoch and the Jurassic Period (roughly 150 to 230 million years ago. The strata in the park show very little structural deformation and the only obvious structures are faults which are intruded by dolerite.

Cement Formation

DEFF Research Database (Denmark)

Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

2012-01-01

Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

Rock Slope Design Criteria

Science.gov (United States)

2010-06-01

Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary : rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, : and siltstones ...

Rock Slope Design Criteria : Executive Summary Report

Science.gov (United States)

2010-06-01

Based on the stratigraphy and the type of slope stability problems, the flat lying, Paleozoic age, sedimentary rocks of Ohio were divided into three design units: 1) competent rock design unit consisting of sandstones, limestones, and siltstones that...

Preliminary Result of Geophysical Some Studieson the Nariinsukhait Coal Deposit

Science.gov (United States)

Norov, B.; Purevjav, N.; Roy, D. K., Sr.

2017-12-01

Nariinsukhait coal deposit has a strategic importance on Mongolian national economic development. The deposit is located in Gurvan-tes of the Umnu-gobi province, as 849 km south-west away from Ulaanbaatar. The deposit in geographically, belongs to Gobi Altai region region of the Altai mountain region. The area contains Permian, Cretaceous, Jurassic, Triassic age of sediments. Sediments are red or sedimentary cover on some part of area (Minjin. Ch., Batnyam. D., Rentsendorj. S (Baatarkhuyag. A., Altantsetseg. D., 2015). The coal deposit is located in the center portion of the Nariinsukhait basin. The age of coal hosted sedimentary rock is Jurassic estimated by Paleo-botanic methodology, using examination of a total 59 kind of plants, 288 pollen grains (Baatarkhuyag. A., Altantsetseg. D., 2015). The thickness of coal hosted sedimentary sequence is approximately 1105.5m and named as Orgilohbulag formation. In case of geophysical exploration, preliminary interpretation of the coal basin has been done by 3 geophysical methodologies which commonly applying during exploration stage of coal. The interpretations are given below. Natural Gamma Sonde /NGRS 4140/: use to determine natural gamma activation on rock by radionuclides content (238U; 235U; 232Th; 40K). During measurements well contrasted coal bedding and, value indicate between 0-15cps. And depending on the rock type it has been changed, in case of siltstone, argillite, conglomerate value fluctuated between 15-40cps. However, those rocks natural gamma values are difference little, therefore not showing much contrast between rock types. Formation Density Sonde Version B /FDSB 4036/: The Nariinsukhait coal deposit Open holes and protective pipes of density is 0.5-1.5 g/cm3, 1.2-2.3 g/cm3 respectively. Not well contrasted during measurement due to some of sedimentary rock density range is so low as such sandstone, siltstone, and conglomerate. Therefore, applied resistivity methodology and done interpretation. DLL3

Seal evaluation and confinement screening criteria for beneficial carbon dioxide storage with enhanced coal bed methane recovery in the Pocahontas Basin, Virginia

Science.gov (United States)

Grimm, R.P.; Eriksson, K.A.; Ripepi, N.; Eble, C.; Greb, S.F.

2012-01-01

The geological storage of carbon dioxide in Appalachian basin coal seams is one possible sink for sequestration of greenhouse gases, with the added benefit of enhanced-coal bed methane (ECBM) recovery. The Pocahontas Basin (part of the central Appalachian Basin) of southwestern Virginia is a major coal bed methane (CBM) province with production mostly from coal beds in the Lower Pennsylvanian Pocahontas and New River formations. As part of the Southeast Regional Carbon Sequestration Partnership's Phase II research program, a CO 2-injection demonstration well was installed into Lower Pennsylvanian coal bed-methane producing strata in southwest Virginia. Samples of siliciclastic lithologies above coal beds in this Oakwood Field well, and from several other cores in the Nora Field were taken to establish a baseline of the basic confinement properties of overlying strata to test seal competency at local and regional scales.Strata above CBM-producing coal beds in the Pocahontas and New River formations consist of dark-gray shales; silty gray shales; heterolithic siltstones, sandstones, and shales; lithic sandstones, and quartzose sandstones. Standard measurements of porosity, permeability and petrography were used to evaluate potential leakage hazards and any possible secondary storage potential for typical lithologies. Both lithic- and quartz-rich sandstones exhibit only minor porosity, with generally low permeability (Member. Analyses of 1500 geophysical logs in southwest Virginia indicate that this unit is moderately thick (>50ft, 15m), laterally continuous (>3000km 2), and a homogenous shale, which coarsens upward into siltstone and sandstone, or is truncated by sandstone. Calculations from two mercury injection capillary porosimetry tests of the shale indicate that a displacement entry pressure of 207psi (1427kPa) would generate an estimated seal capacity of 1365ft (416m) of CO 2 before buoyant leakage. Scanning electron microscopy indicates a microfabric of narrow

Theory of aurora formation

International Nuclear Information System (INIS)

Hasegawa, Akira.

1975-04-01

A new theory of aurora formation is presented based on Alfven wave-electron interaction. The theory explains consistently 1) the electron acceleration process, 2) the formation of auroral layers and 3) the long wave formation in the longitudinal direction. (auth.)

THE SPECIAL STATUS OF EXOGENOUS WORD-FORMATION WITHIN THE GERMAN WORD-FORMATION SYSTEM

OpenAIRE

Zhilyuk Sergey Aleksandrovich

2014-01-01

The article presents the properties of exogenous word-formation system taking into account the existence of two word-formation systems in modern German. On the basis of foreign research which reveal modern trends in German word-formation connected with the internationalization and the development of new European Latin language. The author defines key features of exogenous word-formation, i.e. foreign origin of wordformation units, unmotivated units, unmotivated interchange in base and affixes...

Star formation

International Nuclear Information System (INIS)

Woodward, P.R.

1978-01-01

Theoretical models of star formation are discussed beginning with the earliest stages and ending in the formation of rotating, self-gravitating disks or rings. First a model of the implosion of very diffuse gas clouds is presented which relies upon a shock at the edge of a galactic spiral arm to drive the implosion. Second, models are presented for the formation of a second generation of massive stars in such a cloud once a first generation has formed. These models rely on the ionizing radiation from massive stars or on the supernova shocks produced when these stars explode. Finally, calculations of the gravitational collapse of rotating clouds are discussed with special focus on the question of whether rotating disks or rings are the result of such a collapse. 65 references

Geology of dolomite-hosted uranium deposits at the Pitch Mine, Saguache County, Colorado

International Nuclear Information System (INIS)

Nash, J.T.

1981-01-01

Newly documented uranium ore in the Pitch mine occurs chiefly in brecciated Mississippian Leadville Dolomite along the Chester upthrust zone, and to a lesser extent in sandstone, siltstone, and carbonaceous shale of the Pennsylvanian Belden Formation and in Precambrian granitic rocks and schist. Uranium-mineralized zones are generally thicker, more consistent, and of higher grade in dolomite than in other hosts, and roughly 50 percent of the new reserves are in dolomite. Strong physical control by dolomite is evident, as this is the only rock type that is pervasively brecciated within the fault slices that make up the footwall of the reverse-fault zone. Other rocks tended to either remain unbroken or undergo ductile deformation. Chemical controls on uranium deposition are subtle and appear chiefly to involve coprecipitation of FeS 2 as pyrite and marcasite, suggesting that sulfide ion may be the reductant

Vascular lumen formation.

Science.gov (United States)

Lammert, Eckhard; Axnick, Jennifer

2012-04-01

The vascular system developed early in evolution. It is required in large multicellular organisms for the transport of nutrients, oxygen, and waste products to and from tissues. The vascular system is composed of hollow tubes, which have a high level of complexity in vertebrates. Vasculogenesis describes the de novo formation of blood vessels, e.g., aorta formation in vertebrate embryogenesis. In contrast, angiogenesis is the formation of blood vessels from preexisting ones, e.g., sprouting of intersomitic blood vessels from the aorta. Importantly, the lumen of all blood vessels in vertebrates is lined and formed by endothelial cells. In both vasculogenesis and angiogenesis, lumen formation takes place in a cord of endothelial cells. It involves a complex molecular mechanism composed of endothelial cell repulsion at the cell-cell contacts within the endothelial cell cords, junctional rearrangement, and endothelial cell shape change. As the vascular system also participates in the course of many diseases, such as cancer, stroke, and myocardial infarction, it is important to understand and make use of the molecular mechanisms of blood vessel formation to better understand and manipulate the pathomechanisms involved.

Isothermal Martensite Formation

DEFF Research Database (Denmark)

Villa, Matteo

Isothermal (i.e. time dependent) martensite formation in steel was first observed in the 40ies of the XXth century and is still treated as an anomaly in the description of martensite formation which is considered as a-thermal (i.e. independent of time). Recently, the clarification of the mechanism...... of lattice strains provided fundamental information on the state of stress in the material and clarified the role of the strain energy on martensite formation. Electron backscatter diffraction revealed that the microstructure of the material and the morphology of martensite were independent on the cooling...... leading to isothermal kinetics acquired new practical relevance because of the identification of isothermal martensite formation as the most likely process responsible for enhanced performances of sub-zero Celsius treated high carbon steel products. In the present work, different iron based alloys...

Petrophysics and hydrocarbon potential of Paleozoic rocks in Kuwait

Science.gov (United States)

Abdullah, Fowzia; Shaaban, Fouad; Khalaf, Fikry; Bahaman, Fatma; Akbar, Bibi; Al-Khamiss, Awatif

2017-10-01

Well logs from nine deep exploratory and development wells in Kuwaiti oil fields have been used to study petrophysical characteristics and their effect on the reservoir quality of the subsurface Paleozoic Khuff and Unayzah formations. Petrophysical log data have been calibrated with core analysis available at some intervals. The study indicates a complex lithological facies of the Khuff Formation that is composed mainly of dolomite and anhydrite interbeds with dispersed argillaceous materials and few limestone intercalations. This facies greatly lowered the formation matrix porosity and permeability index. The porosity is fully saturated with water, which is reflected by the low resistivity logs responses, except at some intervals where few hydrocarbon shows are recorded. The impermeable anhydrites, massive (low-permeability) carbonate rock and shale at the lower part of the formation combine to form intraformational seals for the clastic reservoirs of the underlying Unayzah Formation. By contrast, the log interpretation revealed clastic lithological nature of the Unayzah Formation with cycles of conglomerate, sandstone, siltstone, mudstone and shales. The recorded argillaceous materials are mainly of disseminated habit, which control, for some extent, the matrix porosity, that ranges from 2% to 15% with water saturation ranges from 65% to 100%. Cementation, dissolution, compaction and clay mineral authigenesis are the most significant diagenetic processes affecting the reservoir quality. Calibration with the available core analysis at some intervals of the formation indicates that the siliciclastic sequence is a fluvial with more than one climatic cycle changes from humid, semi-arid to arid condition and displays the impact of both physical and chemical diagenesis. In general, the study revealed that the Unyazah Formation has a better reservoir quality than the Khuff Formation and possible gas bearing zones.

Data format translation routines

International Nuclear Information System (INIS)

Burris, R.D.

1981-02-01

To enable the effective connection of several dissimilar computers into a network, modification of the data being passed from one computer to another may become necessary. This document describes a package of routines which permit the translation of data in PDP-8 formats to PDP-11 or DECsystem-10 formats or from PDP-11 format to DECsystem-10 format. Additional routines are described which permit the effective use of the translation routines in the environment of the Fusion Energy Division (FED) network and the Elmo Bumpy Torus (EBT) data base

From Sermon Formation to Preacher Formation

DEFF Research Database (Denmark)

Gaarden, Marianne

2016-01-01

today is less about exercising the authority of an office and more about embodying authenticity. I argue that traditional homiletic education can benefit from implementing a learner-centered approach to teaching moving from sermon formation towards preacher formation, in order to develop and train...... preachers. This involves a learning strategy to ministry where theological skills, pastoral competences, and own personality are interwoven. Teaching here means facilitating a room of learning where teacher’s power and control is reduced, allowing the preacher to reflect upon own practice without being...... judged, evaluated, or critiqued. In this paper, I explain how a learner-centered approach to education works in practice and show how pastors experience the teaching method and the congregations’ positive response to their improvements. I shall present the results of a focus-group interview with pastors...

Feedback in formative OSCEs: comparison between direct observation and video-based formats

Science.gov (United States)

Junod Perron, Noëlle; Louis-Simonet, Martine; Cerutti, Bernard; Pfarrwaller, Eva; Sommer, Johanna; Nendaz, Mathieu

2016-01-01

Introduction Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1) direct observation of an encounter followed by verbal feedback (direct feedback) and 2) subsequent review of the videotaped encounter by both student and supervisor (video-based feedback). The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback) using a 21-item feedback scale. Results Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor). When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively). Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009). Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on the educational

Feedback in formative OSCEs: comparison between direct observation and video-based formats

Directory of Open Access Journals (Sweden)

Noëlle Junod Perron

2016-11-01

Full Text Available Introduction: Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1 direct observation of an encounter followed by verbal feedback (direct feedback and 2 subsequent review of the videotaped encounter by both student and supervisor (video-based feedback. The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods: In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback using a 21-item feedback scale. Results: Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor. When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively. Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009. Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion: Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on

Galaxy Formation

DEFF Research Database (Denmark)

Sparre, Martin

Galaxy formation is an enormously complex discipline due to the many physical processes that play a role in shaping galaxies. The objective of this thesis is to study galaxy formation with two different approaches: First, numerical simulations are used to study the structure of dark matter and how...... galaxies form stars throughout the history of the Universe, and secondly it is shown that observations of gamma-ray bursts (GRBs) can be used to probe galaxies with active star formation in the early Universe. A conclusion from the hydrodynamical simulations is that the galaxies from the stateof...... is important, since it helps constraining chemical evolution models at high redshift. A new project studying how the population of galaxies hosting GRBs relate to other galaxy population is outlined in the conclusion of this thesis. The core of this project will be to quantify how the stellar mass function...

Geology and metallogeny of the volcanic complex of Rio Blanco Ullum. Province of San Juan. Republica Argentina

International Nuclear Information System (INIS)

Mendoza, N.; Weidmann, N.; Puigdomenech, H.; Weidmann, R.

2007-01-01

Preliminary results of a research carried out at the Complejo Rio Blanco de Ullum, San Juan. Argentina are summarized in the present paper. These studies are focused on geological and metallogenic features o f this unit. The study area is located 20 km. WNW of San Juan city with geographic coordinates of 31grades 30' South latitude and 68 grades 52' West longitude. The older rocks aotcroping in the area correspond to limestones of Ordovician San Juan Formation, the chronologic succession continues with sales and siltstones of Silurian Tambolar Formation, pelites and subgraywackes of Devonian Punta Negra Formation and finally a 1500 m thick package of piroclastics and sediments of Albarracin Formation of Tertiary age. Albarracin Formation is composed pf a Basal Member (sandstones and stilstones), a Tuffaceous Member (tuffs, tuffites and oligomictic breccia s with conglomerate interbed dings in the upper part) and a Conglomeratic Member (polimictic para conglomerates). According to piroclastics facies, relationships and spreading area of piroclastics deposits a c olapsed dome and avalanche model is proposed to be the main process for the piroclastics package outcropping in the area.Sedimentary and piroclastics rocks are intruded by five sub volcanic units as noted by Leveratto (1968) which are composed by different lithologies such as: Altered Da cite - Rhyolite, Ullum Da cite, Cerro Blanco de Zonda Andesite, Ullum Andesite and Hybrid Andesite.Detailed work on alteration assemblages and metallogenic features in the southwestern sector of the Complejo resulted in the identification of three alteration zones with characteric features of potassic, argillic and propyllitic signature. (author)

Reconsidering formative measurement.

Science.gov (United States)

Howell, Roy D; Breivik, Einar; Wilcox, James B

2007-06-01

The relationship between observable responses and the latent constructs they are purported to measure has received considerable attention recently, with particular focus on what has become known as formative measurement. This alternative to reflective measurement in the area of theory-testing research is examined in the context of the potential for interpretational confounding and a construct's ability to function as a point variable within a larger model. Although these issues have been addressed in the traditional reflective measurement context, the authors suggest that they are particularly relevant in evaluating formative measurement models. On the basis of this analysis, the authors conclude that formative measurement is not an equally attractive alternative to reflective measurement and that whenever possible, in developing new measures or choosing among alternative existing measures, researchers should opt for reflective measurement. In addition, the authors provide guidelines for researchers dealing with existing formative measures. Copyright 2007 APA, all rights reserved.

Usage Record Format Recommendation

CERN Document Server

Nilsen, J.K.; Muller-Pfeerkorn, R

2013-01-01

For resources to be shared, sites must be able to exchange basic accounting and usage data in a common format. This document describes a common format which enables the exchange of basic accounting and usage data from different resources. This record format is intended to facilitate the sharing of usage information, particularly in the area of the accounting of jobs, computing, memory, storage and cloud usage but with a structure that allows an easy extension to other resources. This document describes the Usage Record components both in natural language form and annotated XML. This document does not address how these records should be used, nor does it attempt to dictate the format in which the accounting records are stored. Instead, it denes a common exchange format. Furthermore, nothing is said regarding the communication mechanisms employed to exchange the records, i.e. transport layer, framing, authentication, integrity, etc.

Stages of ores formation

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1988-01-01

Deposit formation (especially endogenous) is the complicated, multi-stage and long process. Establishment of deposit formation succession, age-specific correlations of minerals and aggregates have a high importance at solving genetic questions. Studying of minerals correlations and mineral aggregates, succession of their crystallization and other observations let restore the history of deposit formation, pick up in it different on duration and physical and chemical conditions stages

Television Format As a Site of Cultural Negotiation: Studying the Structures, Agencies and Practices of Format Adaptation

NARCIS (Netherlands)

Keinonen, Heidi

2016-01-01

abstractDespite the growing number of publications on television formats, specific theorisations regarding formats and format adaptation, in particular, are still rare. In this article, I introduce a synthesizing approach for studying format appropriation. Drawing on format study, media industry

Blistering and bubble formation

International Nuclear Information System (INIS)

Roth, J.

1976-01-01

Blister formation in metals has been observed during bombardment with inert-gas ions in the energy range between 1 and 2000 keV at doses of about 10 17 to 10 19 cm -2 . The changes in surface topography and the erosion yields were mainly studied in the scanning electron microscope (SEM). Additionally the release of the implanted gas during blister formation was observed. Recently measurements on single crystals were performed determining simultaneously the implantation profile, the total amount of trapped ions, the depth distribution of the induced lattice damage and the thickness of the covers of the blisters. In several stages of the formation process of blisters the implanted layer was observed in the transmission electron microscope (TEM) showing the formation of gas bubbles. Using the results of all these measurements in this review an attempt is made to develop a model of blister formation combining the effects of hydrostatic pressure in the gas bubbles and lateral stress due to volume swelling. (author)

Fracturing formations in wells

Energy Technology Data Exchange (ETDEWEB)

Daroza, R A

1964-05-15

This well stimulation method comprises introducing through the well bore a low-penetrating, dilatant fluid, and subjecting the fluid to sufficient pressure to produce fractures in the formation. The fluid is permitted to remain in contact with the formation so as to become diluted by the formation fluids, and thereby lose its properties of dilatancy. Also, a penetrating fluid, containing a propping agent suspended therein, in introduced into contact with the fractures at a pressure substantially reduced with respect to that pressure which would have been required, prior to the fracturing operation performed using the low-penetrating dilatant fluid. The propping agent is deposited within the fractures, and thereafter, fluid production is resumed from the fractured formation. (2 claims)

'TV Format Protection through Marketing Strategies?'

OpenAIRE

Singh, Sukhpreet

2008-01-01

Commercially successful programme ideas are often imitated or adapted. Television formats, in particular, are routinely copied. Starting from radio formats in the 1950s to game shows and reality programme formats of today, producers have accused others of “stealing”. Although formats constitute one of the most important exports for British TV producers, there is still no certainty about the legal protection of TV formats from copycat versions. Since TV formats fail to fall neatly within the d...

Dislocation processes in quasicrystals-Kink-pair formation control or jog-pair formation control

International Nuclear Information System (INIS)

Takeuchi, Shin

2005-01-01

A computer simulation of dislocation in a model quasiperiodic lattice indicates that the dislocation feels a large Peierls potential when oriented in particular directions. For a dislocation with a high Peierls potential, the glide velocity and the climb velocity of the dislocation can be described almost in parallel in terms of the kink-pair formation followed by kink motion and the jog-pair formation followed by jog motion, respectively. The activation enthalpy of the kink-pair formation is the sum of the kink-pair formation enthalpy and the atomic jump activation enthalpy, while the activation enthalpy of the jog-pair formation involves the jog-pair enthalpy and the self-diffusion enthalpy. Since the kink-pair energy can be considerably larger than the jog-pair energy, the climb velocity can be faster than the glide velocity, so that the plastic deformation of quasicrystals can be brought not by dislocation glide but by dislocation climb at high temperatures

Solubility studies of oxovanadium(V) formate and vanadyl formate in aqueous medium

International Nuclear Information System (INIS)

Tripathi, V.S.; Bairwa, K.K.; Naik, D.B.; Raje, N.H.; Bera, S.

2014-01-01

The solubility of oxovanadium(V) formate and vanadyl formate in aqueous medium has been determined. These compounds are important for preparation of strong reducing V(II) compounds which are used in stainless steel based nuclear power plants for decontamination

Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

Directory of Open Access Journals (Sweden)

S. Soto-Caban

2013-08-01

Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

Planet formation in Binaries

OpenAIRE

Thebault, Ph.; Haghighipour, N.

2014-01-01

Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review her...

What Determines Star Formation Rates?

Science.gov (United States)

Evans, Neal John

2017-06-01

The relations between star formation and gas have received renewed attention. We combine studies on scales ranging from local (within 0.5 kpc) to distant galaxies to assess what factors contribute to star formation. These include studies of star forming regions in the Milky Way, the LMC, nearby galaxies with spatially resolved star formation, and integrated galaxy studies. We test whether total molecular gas or dense gas provides the best predictor of star formation rate. The star formation ``efficiency," defined as star formation rate divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all the molecular gas. We suggest ways to further develop the concept of "dense gas" to incorporate other factors, such as turbulence.

Package Formats for Preserved Digital Material

DEFF Research Database (Denmark)

Zierau, Eld

2012-01-01

This paper presents an investigation of the best suitable package formats for long term digital preservation. The choice of a package format for preservation is crucial for future access, thus a thorough analysis of choice is important. The investigation presented here covers setting up requireme......This paper presents an investigation of the best suitable package formats for long term digital preservation. The choice of a package format for preservation is crucial for future access, thus a thorough analysis of choice is important. The investigation presented here covers setting up...... requirements for package formats used for long term preserved digital material, and using these requirements as the basis for analysing a range of package formats. The result of the concrete investigation is that the WARC format is the package format best suited for the listed requirements. Fulfilling...

FORMATE-BASED FLUIDS: FORMULATION AND APPLICATION

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

2008-12-01

Full Text Available Formate-based fluids has been successfully used in over hunders HPHT well operations since they introduced in field practice. They have many advantages when compared with conventional HPHT drilling and completion fluids such as: minimal formation damage, maintenance of additve properties at high temperatures, reduced hydraulic flow resistance, low potential for differential sticking, naturally lubricating, very low corrosion rates, biodegradable and pose little risk to the environment etc. Formate-based fluids can be applied during deep slim hole drilling, shale drilling, reservoir drilling, salt and gas hydrate formations drilling. The laboratory research was carried out to evaluate the rheological behavior of formate-based fluids as a function of temperature. Formate-based fluids were formulated using potassium formate brine, xanthan polymer, PAC, starch and calcium carbonate. Experimental results show that potassium formate improves the thermal stability of polymers.

Radiogeochemical features of hydrothermal metasomatic formations

International Nuclear Information System (INIS)

Plyushchev, E.V.; Ryabova, L.A.; Shatov, V.V.

1978-01-01

Considered are the most general peculiarities of uranium and thorium distributions in hydrothermal-metasomatic formations of three levels of substance formation: 1) in hydrothermal minerals; 2) in natural associations of these minerals (in the altered rocks, metasomatites, ores, etc.); 3) ordened series of zonally and in stage conjugated hydrothermal-metasomatic formations. Statistically stable recurrence of natural combinations of hydrothermal-metasomatic formations points out conjugation of their formation in the directed evolution in the general hydrothermal process. Series of metasomatic formations, the initial members of which are potassium metasomatites, mostly result in accumulation up to industrial concentrations of radioactive elements in final members of these formations. Development of midlow-temperature propylitic alterations in highly radiative rocks causes the same accumulation

ENDF/B Format

International Nuclear Information System (INIS)

Khalil, M.A.

1975-01-01

This document is a brief user's description of the format of ENDF/B, the evaluated neutron nuclear data library of the US National Nuclear Data Center. This summary is an aid to customers of the IAEA Nuclear Data Section when receiving data retrievals in ENDF/B format. For more detailed information the report BNL-50274 (ENDF-102) should be consulted. (author)

Geological factors of deposit formation

International Nuclear Information System (INIS)

Grushevoj, G.V.

1980-01-01

Geologic factors of hydrogenic uranium deposit formation are considered. Structural, formation and lithological-facies factors of deposit formation, connected with zones of stratal oxidation, are characterized. Peculiarities of deposit localization, connected with orogenic structures of Mesozoic and lenozoic age, are described. It is noted that deposits of anagenous group are widely spread in Paleozoic formations, infiltration uranium deposits are localized mainly in Cenozoic sediments, while uranium mineralization both anagenous and infiltration groups are widely developed in Mesozoic sediments. Anagenous deposits were formed in non-oxygen situation, their age varies from 200 to 55 mln years. Infiltration deposit formation is determined by asymmetric oxidation zonation, their age varies from 10 - 40 mln years to dozens of thousand years [ru

Designing for informed group formation

DEFF Research Database (Denmark)

Nicolajsen, Hanne Westh; Juel Jacobsen, Alice; Riis, Marianne

2012-01-01

A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive...

FORMATION CONSTANTS AND THERMODYNAMIC ...

African Journals Online (AJOL)

KEY WORDS: Metal complexes, Schiff base ligand, Formation constant, DFT calculation ... best values for the formation constants of the proposed equilibrium model by .... to its positive charge distribution and the ligand deformation geometry.

A fluvioglacial and gaciolacustrine deltaic depositional model for Permo-Carboniferous coals of the northeastern Karoo Basin, South Africa

Energy Technology Data Exchange (ETDEWEB)

Smith G, Le Blanc; Eriksson, K A

1979-01-01

With the northward retreat of the late Palaeozoic Gondwana ice sheet a series of glacial valleys, partially filled with diamictite, dominated the landscape along the northern edge of the Karoo basin in South Africa. Consequent outwash sediments accumulated as fluvioglacial and glaciolacustrine deltaic deposits. Density underflow generated turbidity currents from which bottomset sediments were deposited. These comprise distal varved siltstones and shales, stratified pebbly-mudstone with dropstones, and proximal ripple drift cross-laminated sandstones and siltstones. Overlying outwash plain conglomerates and sandstones constitute the topset deposits. Upon abandonment of the outwash plain, shallow-rooted Arctic vegetation developed. Resulting peats exceeded 10 m in thickness and constituted precursors to coal seams in which variations in ash content are attributed to overbank splaying from recognisable anastomosing channels within the coal swamps. This study has illustrated a characteristic paraglacial sedimentation sequence, maximum depositional rates occur immediately after glacial retreat followed by decelerating sedimentation rates through time, leading finally to the development of extensive peats. (29 refs.)

Stacked Star Formation Rate Profiles of Bursty Galaxies Exhibit “Coherent” Star Formation

Science.gov (United States)

Orr, Matthew E.; Hayward, Christopher C.; Nelson, Erica J.; Hopkins, Philip F.; Faucher-Giguère, Claude-André; Kereš, Dušan; Chan, T. K.; Schmitz, Denise M.; Miller, Tim B.

2017-11-01

In a recent work based on 3200 stacked Hα maps of galaxies at z˜ 1, Nelson et al. find evidence for “coherent star formation”: the stacked star formation rate (SFR) profiles of galaxies above (below) the “star formation main sequence” (MS) are above (below) that of galaxies on the MS at all radii. One might interpret this result as inconsistent with highly bursty star formation and evidence that galaxies evolve smoothly along the MS rather than crossing it many times. We analyze six simulated galaxies at z˜ 1 from the Feedback in Realistic Environments (FIRE) project in a manner analogous to the observations to test whether the above interpretations are correct. The trends in stacked SFR profiles are qualitatively consistent with those observed. However, SFR profiles of individual galaxies are much more complex than the stacked profiles: the former can be flat or even peak at large radii because of the highly clustered nature of star formation in the simulations. Moreover, the SFR profiles of individual galaxies above (below) the MS are not systematically above (below) those of MS galaxies at all radii. We conclude that the time-averaged coherent star formation evident stacks of observed galaxies is consistent with highly bursty, clumpy star formation of individual galaxies and is not evidence that galaxies evolve smoothly along the MS.

Manuel UNIMARC format bibliographique

CERN Document Server

2007-01-01

This manual is the French translation of the second edition of UNIMARC Manual: bibliographic format published in English in 1994 and completed by 5 updates published from 1996 to 2005. This 5th French edition is composite. It reproduces identically a part of the 4th edition published in 2002 and, for the fields of the format modified in the Update 5, it offers a new more structured presentation. This is a handbook dedicated to French-speaking users of the UNIMARC format for bibliographic descriptions.

Earth formation porosity log

International Nuclear Information System (INIS)

Smith, H.D.; Smith, M.P.; Schultz, W.E.

1977-01-01

A method for determining the porosity of earth formations in the vicinity of a cased well borehole is described, comprising the steps of: irradiating the earth formations in the vicinity of the cased well borehole with fast neutrons from a source of fast neutrons passed into the borehole; and generating a signal representative of the fast neutron population present in the well borehole at a location in the borehole, the signal is functionally related to the porosity of the earth formations in the vicinity of the borehole

Merging formation of FRC and its application to high-beta ST formation

International Nuclear Information System (INIS)

Ono, Y.; Inomoto, M.; Ueda, Y.; Matsuyama, T.; Ohshima, Y.; Katsurai, M.

2001-01-01

Merging formation of field-reversed configuration (FRC) explored not only a new scenario of highly-efficient FRC formation/amplification experiment but also a new boundary research between FRC, spheromak and spherical tokamak (ST). A new finding is that the produced FRC is transformed stably into an ultra-high-β ST by applying external toroidal field B t,ext . The toroidal field was observed to vanish around magnetic axis after the B t,ext application to the FRC, indicating formation of diamagnetic ST. The hollow current profile of FRC was maintained during the equilibrium transition, eliminating a need for the difficult hollow-current-formation process of start-up discharge of high-β ST. The energy-conversion effect of merging transformed the force-free merging spheromaks with paramagnetic current into the FRC with diamagnetic current and the further application of B t,ext did the FRC into the ultra-high-β (>60%)/diamagnetic ST, indicating the close relationship between FRC and ST in second stability. (author)

Restoring formation after leaching process

International Nuclear Information System (INIS)

Barrett, R.B.

1983-01-01

A method of restoring a formation which had uranium and other mineral values extracted by an alkaline lixiviant comprises introducing a source of phosphate in an amount sufficient to lower the level of soluble uranium compounds below that previously existing in the formation by the formation of insoluble uranium phosphate compounds

Formative Research in Educational Media.

Science.gov (United States)

Hodapp, Timothy

This paper distinguishes between basic research, applied research, and evaluation. Evaluation is broken down into two types: summative and formative. The limitations of formative research are presented, followed by a discussion of the value of the formative researcher participating in the product planning process. The types of data which formative…

Meningococcal biofilm formation

DEFF Research Database (Denmark)

Lappann, M.; Haagensen, Janus Anders Juul; Claus, H.

2006-01-01

We show that in a standardized in vitro flow system unencapsulated variants of genetically diverse lineages of Neisseria meningitidis formed biofilms, that could be maintained for more than 96 h. Biofilm cells were resistant to penicillin, but not to rifampin or ciprofloxacin. For some strains......, microcolony formation within biofilms was observed. Microcolony formation in strain MC58 depended on a functional copy of the pilE gene encoding the pilus subunit pilin, and was associated with twitching of cells. Nevertheless, unpiliated pilE mutants formed biofilms showing that attachment and accumulation......X alleles was identified among genetically diverse meningococcal strains. PilX alleles differed in their propensity to support autoaggregation of cells in suspension, but not in their ability to support microcolony formation within biofilms in the continuous flow system....

Tritiated ammonia formation

International Nuclear Information System (INIS)

Heung, L.K.

1995-01-01

When nitrogen was selected as the glovebox atmosphere for the Replacement Tritium Facility (RTF) at the Savannah River Site (SRS), a concern was raised as to the possibility of tritiated ammonia formation in the gloveboxes. Experimental data were produced to study the tritiated ammonia formation rate in a tritium and nitrogen mixture. A rate equation that closely simulates the experimental data was developed. This rate equation can be used to calculate the formation of tritiated ammonia from different concentrations of tritium and nitrogen. The reaction of T 2 and N 2 to form NT 3 is a slow process, particularly when the tritium concentration is low. The reaction requires weeks or months to reach radiochemical equilibrium dependent on the concentrations of the reactants. 4 refs., 6 figs., 1 tab

The NeXus data format

OpenAIRE

Könnecke, Mark; Akeroyd, Frederick A.; Osborn, Raymond; Peterson, Peter F.; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim; Bernstein, Herbert J.; Brewster, Aaron S.; Campbell, Stuart I.; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe

2015-01-01

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamlin...

Inside-out Planet Formation. IV. Pebble Evolution and Planet Formation Timescales

Science.gov (United States)

Hu, Xiao; Tan, Jonathan C.; Zhu, Zhaohuan; Chatterjee, Sourav; Birnstiel, Tilman; Youdin, Andrew N.; Mohanty, Subhanjoy

2018-04-01

Systems with tightly packed inner planets (STIPs) are very common. Chatterjee & Tan proposed Inside-out Planet Formation (IOPF), an in situ formation theory, to explain these planets. IOPF involves sequential planet formation from pebble-rich rings that are fed from the outer disk and trapped at the pressure maximum associated with the dead zone inner boundary (DZIB). Planet masses are set by their ability to open a gap and cause the DZIB to retreat outwards. We present models for the disk density and temperature structures that are relevant to the conditions of IOPF. For a wide range of DZIB conditions, we evaluate the gap-opening masses of planets in these disks that are expected to lead to the truncation of pebble accretion onto the forming planet. We then consider the evolution of dust and pebbles in the disk, estimating that pebbles typically grow to sizes of a few centimeters during their radial drift from several tens of astronomical units to the inner, ≲1 au scale disk. A large fraction of the accretion flux of solids is expected to be in such pebbles. This allows us to estimate the timescales for individual planet formation and the entire planetary system formation in the IOPF scenario. We find that to produce realistic STIPs within reasonable timescales similar to disk lifetimes requires disk accretion rates of ∼10‑9 M ⊙ yr‑1 and relatively low viscosity conditions in the DZIB region, i.e., a Shakura–Sunyaev parameter of α ∼ 10‑4.

PCF File Format.

Energy Technology Data Exchange (ETDEWEB)

Thoreson, Gregory G [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-08-01

PCF files are binary files designed to contain gamma spectra and neutron count rates from radiation sensors. It is the native format for the GAmma Detector Response and Analysis Software (GADRAS) package [1]. It can contain multiple spectra and information about each spectrum such as energy calibration. This document outlines the format of the file that would allow one to write a computer program to parse and write such files.

Two dimentional modeling of subsurface structure over upper Benue ...

African Journals Online (AJOL)

The subsurface lithology obtained from 2D modelling of the residual field showed the presence of two lithological units. The sedimentary rock unit underlined by the basement rock consists of shales, sandstones, limestones, siltstones, clay and non-marine facies. The Basement rock units were composed of pegmatite, ...

76 FR 73658 - Notice of Intent to Repatriate Cultural Items: Tennessee Valley Authority and the University of...

Science.gov (United States)

2011-11-29

...; six shell pendants; three pieces of glass; three samples of red ochre; three mink skull fragments; one... made from iron, brass, pewter, silver and lead; three glass mirrors or mirror fragments; six glass... piece of smelted lead; four steatite pipes; one catlinite pipe; two clay siltstone pipes; three...

Spatially-resolved star formation histories of CALIFA galaxies. Implications for galaxy formation

Science.gov (United States)

González Delgado, R. M.; Pérez, E.; Cid Fernandes, R.; García-Benito, R.; López Fernández, R.; Vale Asari, N.; Cortijo-Ferrero, C.; de Amorim, A. L.; Lacerda, E. A. D.; Sánchez, S. F.; Lehnert, M. D.; Walcher, C. J.

2017-11-01

This paper presents the spatially resolved star formation history (SFH) of nearby galaxies with the aim of furthering our understanding of the different processes involved in the formation and evolution of galaxies. To this end, we apply the fossil record method of stellar population synthesis to a rich and diverse data set of 436 galaxies observed with integral field spectroscopy in the CALIFA survey. The sample covers a wide range of Hubble types, with stellar masses ranging from M⋆ 109 to 7 × 1011 M⊙. Spectral synthesis techniques are applied to the datacubes to retrieve the spatially resolved time evolution of the star formation rate (SFR), its intensity (ΣSFR), and other descriptors of the 2D SFH in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd) and five bins of stellar mass. Our main results are that (a) galaxies form very fast independently of their current stellar mass, with the peak of star formation at high redshift (z > 2). Subsequent star formation is driven by M⋆ and morphology, with less massive and later type spirals showing more prolonged periods of star formation. (b) At any epoch in the past, the SFR is proportional to M⋆, with most massive galaxies having the highest absolute (but lowest specific) SFRs. (c) While today, the ΣSFR is similar for all spirals and significantly lower in early-type galaxies (ETG), in the past, the ΣSFR scales well with morphology. The central regions of today's ETGs are where the ΣSFR reached the highest values (> 103 M⊙ Gyr-1 pc-2), similar to those measured in high-redshift star-forming galaxies. (d) The evolution of ΣSFR in Sbc systems matches that of models for Milky Way-like galaxies, suggesting that the formation of a thick disk may be a common phase in spirals at early epochs. (e) The SFR and ΣSFR in outer regions of E and S0 galaxies show that they have undergone an extended phase of growth in mass between z = 2 and 0.4. The mass assembled in this phase is in agreement with

Formation of multiple networks

DEFF Research Database (Denmark)

Magnani, Matteo; Rossi, Luca

2013-01-01

we introduce the first network formation model for multiple networks. Network formation models are among the most popular tools in traditional network studies, because of both their practical and theoretical impact. However, existing models are not sufficient to describe the generation of multiple...

Autonomous Formations of Multi-Agent Systems

Science.gov (United States)

Dhali, Sanjana; Joshi, Suresh M.

2013-01-01

Autonomous formation control of multi-agent dynamic systems has a number of applications that include ground-based and aerial robots and satellite formations. For air vehicles, formation flight ("flocking") has the potential to significantly increase airspace utilization as well as fuel efficiency. This presentation addresses two main problems in multi-agent formations: optimal role assignment to minimize the total cost (e.g., combined distance traveled by all agents); and maintaining formation geometry during flock motion. The Kuhn-Munkres ("Hungarian") algorithm is used for optimal assignment, and consensus-based leader-follower type control architecture is used to maintain formation shape despite the leader s independent movements. The methods are demonstrated by animated simulations.

GMC Collisions as Triggers of Star Formation. III. Density and Magnetically Regulated Star Formation

Energy Technology Data Exchange (ETDEWEB)

Wu, Benjamin [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Tan, Jonathan C. [Department of Physics, University of Florida, Gainesville, FL 32611 (United States); Christie, Duncan [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Nakamura, Fumitaka [National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Van Loo, Sven [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Collins, David, E-mail: ben.wu@nao.ac.jp [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

2017-06-01

We study giant molecular cloud (GMC) collisions and their ability to trigger star cluster formation. We further develop our three-dimensional magnetized, turbulent, colliding GMC simulations by implementing star formation subgrid models. Two such models are explored: (1) “Density-Regulated,” i.e., fixed efficiency per free-fall time above a set density threshold and (2) “Magnetically Regulated,” i.e., fixed efficiency per free-fall time in regions that are magnetically supercritical. Variations of parameters associated with these models are also explored. In the non-colliding simulations, the overall level of star formation is sensitive to model parameter choices that relate to effective density thresholds. In the GMC collision simulations, the final star formation rates and efficiencies are relatively independent of these parameters. Between the non-colliding and colliding cases, we compare the morphologies of the resulting star clusters, properties of star-forming gas, time evolution of the star formation rate (SFR), spatial clustering of the stars, and resulting kinematics of the stars in comparison to the natal gas. We find that typical collisions, by creating larger amounts of dense gas, trigger earlier and enhanced star formation, resulting in 10 times higher SFRs and efficiencies. The star clusters formed from GMC collisions show greater spatial substructure and more disturbed kinematics.

A format for phylogenetic placements.

Directory of Open Access Journals (Sweden)

Frederick A Matsen

Full Text Available We have developed a unified format for phylogenetic placements, that is, mappings of environmental sequence data (e.g., short reads into a phylogenetic tree. We are motivated to do so by the growing number of tools for computing and post-processing phylogenetic placements, and the lack of an established standard for storing them. The format is lightweight, versatile, extensible, and is based on the JSON format, which can be parsed by most modern programming languages. Our format is already implemented in several tools for computing and post-processing parsimony- and likelihood-based phylogenetic placements and has worked well in practice. We believe that establishing a standard format for analyzing read placements at this early stage will lead to a more efficient development of powerful and portable post-analysis tools for the growing applications of phylogenetic placement.

Uranium logging in earth formations

International Nuclear Information System (INIS)

Givens, W.W.

1979-01-01

A technique is provided for assaying the formations surrounding a borehole for uranium. A borehole logging tool cyclically irradiates the formations with neutrons and responds to neutron fluxes produced during the period of time that prompt neutrons are being produced by the neutron fission of uranium in the formations. A borehole calibration tool employs a steady-state (continuous output) neutron source, firstly, to produce a response to neutron fluxes in models having known concentrations of uranium and, secondly, to to produce a response to neutron fluxes in the formations surrounding the borehole. The neutron flux responses of the borehole calibration tool in both the model and the formations surrounding the borehole are utilized to correct the neutron flux response of the borehole logging tool for the effects of epithermal/thermal neutron moderation, scattering, and absorption within the borehole itself

Alteration of uraniferous and native copper concretions in the Permian mudrocks of south Devon, United Kingdom

International Nuclear Information System (INIS)

Milodowski, A.E.; Styles, M.T.; Horstwood, M.S.A.; Kemp, S.J.

2002-03-01

This report presents the results of a study of the mineralogy and alteration characteristics of unusual concretions containing sheets of native copper, and uranium-vanadium mineralised concretions, in mudstones and siltstones of the Pennian Littleham Mudstone Formation, at Littleham Cove, south Devon, England. The main objectives of the study were: 1. To investigate the corrosion characteristics of the native copper as a natural analogue for the long-term behaviour of copper canisters, sealed in a compacted clay (bentonite) backfill, that will be used for the deep geological disposal of spent fuel and high-level radioactive waste (HLW). This study developed from an earlier pilot study, which demonstrated that the alteration of the native copper in the concretions from Littleham Cove was mineralogically and chemically complex. 2. To investigate the alteration and oxidation of minerals containing reduced species (e.g. ferrous iron) within the uranium-rich concretions as a natural analogue for the potential effects of oxidation induced by alpha-radiolysis of water in a HLW repository environment. Native copper-bearing concretions in the Littleham Mudstone Formation are very rare. They occur, as thin lenticular disks developed largely along bedding lamina and thin low-angle fractures cutting the bedding laminae the upper part of the formation, about 10 m below the top of the formation. This part of the sequence comprises laterally discontinuous, fine-grained sheet-flood and channel sandstones and siltstones. Some of these sandstones, are more extensively-cemented by copper sulphides (mainly chalcocite), copper arsenides, cobalt-nickel arsenides, and uranium silicate. The thin permeable sandstones and siltstones, and fractures zones around small faults appear to have acted as the conduits for the movement of mineralising fluids through the mudstones. The native copper sheets all show a similar pattern of corrosion and alteration. However, the intensity of alteration is

Free-format RPG IV

CERN Document Server

Martin, Jim

2013-01-01

This how-to guide offers a concise and thorough introduction to the increased productivity, better readability, and easier program maintenance that comes with the free-format style of programming in RPG IV. Although free-format information is available in IBM manuals, it is not separated from everything else, thereby requiring hours of tedious research to track down the information needed. This book provides everything one needs to know to write RPG IV in the free-format style, and author Jim Martin not only teaches rules and syntax but also explains how this new style of coding has the pot

Clay minerals in uraniferous deposit of Imouraren (Tim Mersoi basin, Niger): implications on genesis of deposit and on ore treatment process

International Nuclear Information System (INIS)

Billon, Sophie

2014-01-01

Nigerian uraniferous deposits are located in carboniferous and Jurassic formations of Tim Mersoi basin. AREVA is shareholder of 3 mine sites in this area: SOMAIR and COMINAK, both in exploitation since 1960's and IMOURAREN, 80 km further South, whose exploitation is planned for 2015. Mineralization of Imouraren deposit is included in the fluvial formation of Tchirezrine 2 (Jurassic), composed of channels and flood plains. Facies of channel in-fillings range from coarse sandstones to siltstones, while overflow facies are composed of analcimolites. Secondary mineralogy was acquired during 2 stages: 1- diagenesis, with formation of clay minerals, analcime, secondary quartz and albites, and 2- stage of fluids circulations, which induced alteration of detrital and diagenetic minerals, formation of new phases and uranium deposition. A mineralogical zoning, at the scale of deposit resulted from this alteration. The heterogeneity of Tchirezrine 2, at the level of both facies and mineralogy, is also evidenced during ore treatment, as ore reacts differently depending on its source, with sometimes problems of U recovery. Ore treatment tests showed that analcimes and chlorites were both penalizing minerals, because of 1- the sequestration of U-bearing minerals into analcimes, 2- their dissolution which trends to move away from U solubilization conditions (pH and Eh) and to form numerous sulfates, and 3- problems of percolation. A detection method of analcime-rich ores, based on infrared spectroscopy, was developed in order to optimize ore blending and so to reduce negative effects during ore treatment process. (author)

Implications of diapir-derived detritus and gypsic paleosols in Lower Triassic strata near the Castle Valley salt wall, Paradox Basin, Utah

Science.gov (United States)

Lawton, Timothy F.; Buck, Brenda J.

2006-10-01

Gypsum-bearing growth strata and sedimentary facies of the Moenkopi Formation on the crest and NE flank of the Castle Valley salt wall in the Paradox Basin record salt rise, evaporite exposure, and salt-withdrawal subsidence during the Early Triassic. Detrital gypsum and dolomite clasts derived from the middle Pennsylvanian Paradox Formation were deposited in strata within a few kilometers of the salt wall and indicate that salt rise rates roughly balanced sediment accumulation, resulting in long-term exposure of mobile evaporite. Deposition took place primarily in flood-basin or inland sabkha settings that alternated between shallow subaqueous and subaerial conditions in a hyperarid climate. Matrix-supported and clast-supported conglomerates with gypsum fragments represent debris-flow deposits and reworked debris-flow deposits, respectively, interbedded with flood-basin sandstone and siltstone during development of diapiric topography. Mudstone-rich flood-basin deposits with numerous stage I to III gypsic paleosols capped by eolian gypsum sand sheets accumulated during waning salt-withdrawal subsidence. Association of detrital gypsum, eolian gypsum, and gypsic paleosols suggests that the salt wall provided a common source for gypsum in the surrounding strata. This study documents a previously unrecognized salt weld with associated growth strata containing diapir-derived detritus and gypsic palesols that can be used to interpret halokinesis.

Reflections about the mathematics teachers' formation

Directory of Open Access Journals (Sweden)

Maria José de Freitas Mendes

2010-06-01

Full Text Available This paper brings some reflections about the formation of the math teacher that made part of my marsters paper and that aimed to investigate the process of formation of the math teacher. The focus of this study incided at the contributions of teaching practice in the teacher's formation above the new paradigms of formation, as a professional development and as a reflexive teacher. These reflections, from the learning and teaching process and from the meaning of form a teacher analyse the crisis and the restructuration of the teacher's formation and conclude being necessary that in the graduation courses there's a character more practice to the pedagogical formation, making possible for the future teacher to develop attitudes of autonomy, reflexion and investigation

A possible formation scenario for dwarf spheroidal galaxies - III. Adding star formation histories to the fiducial model

Science.gov (United States)

Alarcón Jara, A. G.; Fellhauer, M.; Matus Carrillo, D. R.; Assmann, P.; Urrutia Zapata, F.; Hazeldine, J.; Aravena, C. A.

2018-02-01

Dwarf spheroidal galaxies are regarded as the basic building blocks in the formation of larger galaxies and are the most dark matter dominated systems in the Universe, known so far. There are several models that attempt to explain their formation and evolution, but they have problems modelling the formation of isolated dwarf spheroidal galaxies. Here, we will explain a possible formation scenario in which star clusters form inside the dark matter halo of a dwarf spheroidal galaxy. These star clusters suffer from low star formation efficiency and dissolve while orbiting inside the dark matter halo. Thereby, they build the faint luminous components that we observe in dwarf spheroidal galaxies. In this paper, we study this model by adding different star formation histories to the simulations and compare the results with our previous work and observational data to show that we can explain the formation of dwarf spheroidal galaxies.

Plant Formate Dehydrogenase

Energy Technology Data Exchange (ETDEWEB)

John Markwell

2005-01-10

The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

Formation à distance et activité du stagiaire de la formation professionnelle continue

OpenAIRE

Verquin-Savarieau, Béatrice

2014-01-01

Quels contenus des lettres de missions pour quelles démarches et activités d’ingénierie de formation, pour des étudiants salariés en activité et suivant leurs études à distance ? Cet article questionne le stage de formation professionnelle continue dans le cadre d’une formation hybride. Il s’agit d’interroger en particulier la conception de la mission de stage, en tant que contenu opératoire facilitant les transformations des sujets dans l’action. Nous présenterons le rôle crucial joué par la...

XML-based DICOM data format.

Science.gov (United States)

Yu, Cong; Yao, Zhihong

2010-04-01

To enhance the readability, improve the structure, and facilitate the sharing of digital imaging and communications in medicine (DICOM) files, this research proposed one kind of XML-based DICOM data format. Because XML Schema offers great flexibility for expressing constraints on the content model of elements, we used it to describe the new format, thus making it consistent with the one originally defined by DICOM. Meanwhile, such schemas can be used in the creation and validation of the XML-encoded DICOM files, acting as a standard for data transmission and sharing on the Web. Upon defining the new data format, we started with representing a single data element and further improved the whole data structure with the method of modularization. In contrast to the original format, the new one possesses better structure without loss of related information. In addition, we demonstrated the application of XSLT and XQuery. All of the advantages mentioned above resulted from this new data format.

The Carboniferous of the Western Karakoram (Pakistan)

Science.gov (United States)

Gaetani, M.; Zanchi, A.; Angiolini, L.; Olivini, G.; Sciunnach, D.; Brunton, H.; Nicora, A.; Mawson, R.

2004-05-01

The results of the study of the Carboniferous successions in the western part of the Northern Karakoram during three geological expeditions are summarized here. Rocks of that period are not uniformly preserved in the several thrust sheets forming the Northern Karakoram. In most of them only the basal part of the Carboniferous, up to the Visean, is preserved, whilst in the Karambar thrust sheet a more complete section—previously almost unknown—is preserved. Four new lithostratigraphic units, time-constrained by brachiopod and conodont biostratigraphy, are described, from bottom to top: (1) the Margach Formation: prevailing dark shales with subordinate fine subarkoses and quartzarenites, up to 300 m thick (mid-Famennian to middle Tournaisian); (2) the Ribat Formation: grey crinoidal limestones passing upwards to dark marly limestones and marls, at least 300 m thick (middle Tournaisian to Serpukhovian); (3) the Lupsuk Formation: subarkoses to feldspathic quartzarenites in thick beds, alternating with dark shales and siltstones, up to 400 m thick (Serpukhovian to uppermost Carboniferous); (4) within the Lupsuk Formation a local member, the Twin Valleys Member, up to 100 m thick, a bioclastic limestone intercalation of post-Moscovian age, is distinguished. The Carboniferous successions are invariably sealed by the arkoses to quartzarenites of the Gircha Formation, 133 m above the base of which, in the Karambar area, an Asselian brachiopod fauna was recovered. The Carboniferous succession is interpreted as recording the evolution of the passive margin of the Northern Karakoram Terrane, from early rifting stage in the Late Devonian to syn-rift events during the Late Carboniferous. The basal part of the Gircha Formation, of latest Carboniferous-earliest Permian age, is considered to have been deposited above a break-up unconformity, linked to the early drifting in the seaway bordering the Karakoram. In the palaeontological appendix the most significant brachiopod taxa

Alteration geochemistry of the volcanic-hosted Dedeninyurdu, Yergen and Fındıklıyar Fe-Cu mineralization at Gökçedoǧan, Çorum-Kargi region, Turkey

Science.gov (United States)

Gumus, Lokman; Öztürk, Sercan; Yalçın, Cihan; Abdelnasser, Amr; Hanilçi, Nurullah; Kumral, Mustafa

2016-04-01

This study is to determine the mass/volume gain and loss of the major and trace elements during the alteration processes on Dedeninyurdu, Yergen and Fındıklıyar Fe-Cu mineralizations of the area. Fe-Cu mineralization occurred in the spilitic volcanic a rock of Saraycık Formation is associated with the different types of alteration zones which are pyritization, silicification and sericitization. The study area comprises Bekirli Formation, Saraycık Formation, Beşpınar Formation, and Ilgaz Formation. Saraycık formation consists of spilitic volcanic rocks with pelagic limestone, siltstone and chert. The ore mineralogical data show that the pyrite, chalcopyrite, covellite, hematite, malachite and goethite formed during three phases of mineralization. As well as the geologic and petrographic studies reveal three alteration zones with definite mineral assemblages; phyllic alteration (quartz + sericite + pyrite) that represents the main alteration and mineralized zone; propylitic alteration; and carbonatized sericitic alteration zone. The boundaries between these zones are gradual. Mass balance calculations suggested that the phyllic alteration zone represented by gain in Si, Fe, K, S, and LOI and loss in Mg, Ca, and Na refers to silicification, sericitization and pyritization as well as replacement of Fe-Mg silicate and plagioclase. While, in the propylitic alteration zone, enrichment of Si, Fe, Mg, LOI and S occurred with depletions of Ca, Na, and K reflecting chloritization alteration type. On the other hand, carbonatized sericitic alteration zone shows local gain in Si, CaO and K reflects the occurrence of calc-silicate alteration. All alteration zones contain a large proportion of sulfide minerals (gain in S) with increase in loss on ignition (LOI). Keywords: Alteration geochemistry; Mass balance calculation, Fe-Cu mineralization; phyllic alteration, propylitic alteration.

Mesoarchean Banded Iron Formation sequences in Dixon Island-Cleaverville Formation, Pilbara Australia: Oxygenic signal from DXCL project

Science.gov (United States)

Kiyokawa, S.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Naraoka, H.; Onoue, T.; Horie, K.; Sakamoto, R.; Aihara, Y.; Miki, T.

2013-12-01

The 3.2-3.1 Ga Dixon island-Cleaverville formations are well-preserved Banded Iron Formation (BIF) within hydrothermal oceanic sequence at oceanic island arc setting (Kiyokawa et al., 2002, 2006, 2012). The stratigraphy of the Dixon Island (3195+15Ma) -Cleaverville (3108+13Ma) formations shows the well preserved environmental condition at the Mesoarchean ocean floor. The stratigraphy of these formations are formed about volcano-sedimentary sequences with hydrothermal chert, black shale and banded iron formation to the top. Based on the scientific drilling of DXCL project at 2007 and 2011, detail lithology between BIF sequence was clearly understood. Four drilling holes had been done at coastal sites; the Dixon Island Formation is DX site (100m) and the Cleaverville Formation is CL2 (40m), CL1 (60m) and CL3 (200m) sites and from stratigraphic bottom to top. Coarsening and thickening upward black shale-BIF sequences are well preserved of the stratigraphy form the core samples. The Dixon Island Formation consists komatiite-rhyolite sequences with many hydrothermal veins and very fine laminated cherty rocks above them. The Cleaverville Formation contains black shale, fragments-bearing pyroclastic beds, white chert, greenish shale and BIF. The CL3 core, which drilled through BIF, shows siderite-chert beds above black shale identified before magnetite lamination bed. U-Pb SHRIMP data of the tuff in lower Dixon Island Formation is 3195+15 Ma and the pyroclastic sequence below the Cleaverville BIF is 3108+13 Ma. Sedimentation rate of these sequence is 2-8 cm/ 1000year. The hole section of the organic carbon rich black shales below BIF are similar amount of organic content and 13C isotope (around -30per mill). There are very weak sulfur MIF signal (less 0.2%) in these black shale sequence. Our result show that thick organic rich sediments may be triggered to form iron rich siderite and magnetite iron beds. The stratigraphy in this sequence quite resemble to other Iron

Observsational Planet Formation

Science.gov (United States)

Dong, Ruobing; Zhu, Zhaohuan; Fung, Jeffrey

2017-06-01

Planets form in gaseous protoplanetary disks surrounding newborn stars. As such, the most direct way to learn how they form from observations, is to directly watch them forming in disks. In the past, this was very difficult due to a lack of observational capabilities; as such, planet formation was largely a subject of pure theoretical astrophysics. Now, thanks to a fleet of new instruments with unprecedented resolving power that have come online recently, we have just started to unveil features in resolve images of protoplanetary disks, such as gaps and spiral arms, that are most likely associated with embedded (unseen) planets. By comparing observations with theoretical models of planet-disk interactions, the masses and orbits of these still forming planets may be constrained. Such planets may help us to directly test various planet formation models. This marks the onset of a new field — observational planet formation. I will introduce the current status of this field.

Les métiers innovants de la formation. Le champ de la formation professionnelle et l'ingénierie de formation à distance

OpenAIRE

Marty, Olivier

2013-01-01

National audience; This document is extracted from a conference for PhD students at La Sorbonne University (Paris) about innovative teaching professions. It describes and analyses the crafts of vocational education as well as public distance education engineering.; Ce document est le support d'une conférence sur les métiers innovants de la formation. Après les définitions d'usage, il décrit et analyse les métiers de la formation professionnelle continue et l'ingénierie de formation à distance...

Types of tectonic structures, sedimentary volcanogenetic formations of a mantle, favourable processes for exogenetic and polygenetic uranium deposits formation

International Nuclear Information System (INIS)

Danchev, V.I.; Komarnitskij, G.M.; Levin, V.N.; Shumlyanskij, V.A.

1985-01-01

Factors, affecting mineralization processes are considered. Characteristic features of uranium-bearing provinces are as follows: the presence of crust of continental type; deep-seated tectonic structures-rises and saggings, roofs, gneiss domes, rift zones and transform fractures; specialization for uranium of sedimentary and magmatic formations; the presence of manifestation regions of deep thermal and gaseous flow, etc. In uranium-bearing provinces territories favourable for the manifestation of different types of uranium mineralization: metamorphogenetic, polygenetic and exogenetic ones, are singled out. Different epochs of uranium ore formation are established. In sedimentary masses tectonic regime and climate are of special importance, and for epigenetic deposits, formed with an aid of underground waters-hydrogeological conditions. In the limits of the main structural elements of the Earth crust and geotectonic structures of higher orders the following types of sedimentary and volcanic formations can be singled out: 1-formations with exogenous uranium mineralization; 2-formations, accumulated in the epochs of epigenous ore formation; 3-formations fav ourable for epigenous uranium deposit formation; 4-formations unfavourable for the formation and localization of uranium mineralization

An Adaptable Seismic Data Format

Science.gov (United States)

Krischer, Lion; Smith, James; Lei, Wenjie; Lefebvre, Matthieu; Ruan, Youyi; de Andrade, Elliott Sales; Podhorszki, Norbert; Bozdağ, Ebru; Tromp, Jeroen

2016-11-01

We present ASDF, the Adaptable Seismic Data Format, a modern and practical data format for all branches of seismology and beyond. The growing volume of freely available data coupled with ever expanding computational power opens avenues to tackle larger and more complex problems. Current bottlenecks include inefficient resource usage and insufficient data organization. Properly scaling a problem requires the resolution of both these challenges, and existing data formats are no longer up to the task. ASDF stores any number of synthetic, processed or unaltered waveforms in a single file. A key improvement compared to existing formats is the inclusion of comprehensive meta information, such as event or station information, in the same file. Additionally, it is also usable for any non-waveform data, for example, cross-correlations, adjoint sources or receiver functions. Last but not least, full provenance information can be stored alongside each item of data, thereby enhancing reproducibility and accountability. Any data set in our proposed format is self-describing and can be readily exchanged with others, facilitating collaboration. The utilization of the HDF5 container format grants efficient and parallel I/O operations, integrated compression algorithms and check sums to guard against data corruption. To not reinvent the wheel and to build upon past developments, we use existing standards like QuakeML, StationXML, W3C PROV and HDF5 wherever feasible. Usability and tool support are crucial for any new format to gain acceptance. We developed mature C/Fortran and Python based APIs coupling ASDF to the widely used SPECFEM3D_GLOBE and ObsPy toolkits.

Planetesimals and Planet Formation

Science.gov (United States)

Chambers, John

The first step in the standard model for planet formation is the growth of gravitationally bound bodies called ``planetesimals'' from dust grains in a protoplanetary disk. Currently, we do not know how planetesimals form, how long they take to form, or what their sizes and mechanical properties are. The goal of this proposal is to assess how these uncertainties affect subsequent stages of planetary growth and the kind of planetary systems that form. The work will address three particular questions: (i) Can the properties of small body populations in the modern Solar System constrain the properties of planetesimals? (ii) How do the properties of planetesimals affect the formation of giant planets? (iii) How does the presence of a water ice condensation front (the ``snow line'') in a disk affect planetesimal formation and the later stages of planetary growth? These questions will be examined with computer simulations of planet formation using new computer codes to be developed as part of the proposal. The first question will be addressed using a statistical model for planetesimal coagulation and fragmentation. This code will be merged with the proposer's Mercury N-body integrator code to model the dynamics of large protoplanets in order to address the second question. Finally, a self- consistent model of disk evolution and the radial transport of water ice and vapour will be added to examine the third question. A theoretical understanding of how planets form is one of the key goals of NASA and the Origins of Solar Systems programme. Researchers have carried out many studies designed to address this goal, but the questions of how planetesimals form and how their properties affect planet formation have received relatively little attention. The proposed work will help address these unsolved questions, and place other research in context by assessing the importance of planetesimal origins and properties for planet formation.

Formation of double layers

International Nuclear Information System (INIS)

Leung, P.; Wong, A.Y.; Quon, B.H.

1981-01-01

Experiments on both stationary and propagating double layers and a related analytical model are described. Stationary double layers were produced in a multiple plasma device, in which an electron drift current was present. An investigation of the plasma parameters for the stable double layer condition is described. The particle distribution in the stable double layer establishes a potential profile, which creates electron and ion beams that excite plasma instabilities. The measured characteristics of the instabilities are consistent with the existence of the double layer. Propagating double layers are formed when the initial electron drift current is large. Ths slopes of the transition region increase as they propagate. A physical model for the formation of a double layer in the experimental device is described. This model explains the formation of the low potential region on the basis of the space charge. This space charge is created by the electron drift current. The model also accounts for the role of ions in double layer formation and explains the formation of moving double layers. (Auth.)

Medusae Fossae Formation

Science.gov (United States)

2002-01-01

(Released 10 April 2002) The Science This THEMIS visible image was acquired near 7o S, 172o W (188o E) and shows a remarkable martian geologic deposit known as the Medusae Fossae Formation. This Formation, seen here as the raised plateau in the upper two-thirds of the image, is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region the deposit has been heavily eroded by the wind to produce a series of linear ridges called yardangs. These parallel ridges point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to sculpt the dry landscape of Mars. The Medusae Fossae Formation has been completely stripped from the surface in the lower third of the image, revealing a harder layer below that is more resistant to wind erosion. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Several ancient craters that were once completely buried by this deposit are being exposed, or exhumed, as the overlying Medusae Formation is removed. Very few impact craters are visible on this Formation, indicating that the surface seen today is relatively young, and that the processes of erosion are likely to be actively occurring. The Story Medusa of Greek mythology fame, the name-giver to this region, had snaky locks of hair that could turn a person to stone. Wild and unruly, this monster of the underworld could certainly wreak havoc on the world of the human imagination. As scary as she was, Medusa would have no advantage over the fierce, masterful winds blowing across Mars, which once carved the streaky, terrain at the top of this image. Wild and whipping, these winds have slowly eroded away the 'topsoil,' revealing ancient craters and other surface features they once covered. The loosely cemented particles of this 'topsoil' are likely made up of dust

Designing for informed group formation

DEFF Research Database (Denmark)

Nicolajsen, Hanne Westh; Juel Jacobsen, Alice; Riis, Marianne

2012-01-01

A new design ―project preparation‖ preparing for the group formation in problem based project work is proposed and investigated. The main problem is to overcome group formation based on existing relations. The hypothesis is that theme development and group formation are somewhat counterproductive....... Following research based design methodology an experiment separating the two was initiated.This was to provide for more openness and creativity in contrast to a design in which existing relations seem predominant....

Origin and evolution processes of hybrid event beds in the Lower Cretaceous of the Lingshan Island, Eastern China

DEFF Research Database (Denmark)

Yang, Tian; Cao, Yingchang; Friis, Henrik

2018-01-01

is sharp. HEB 2 may be developed by up-dip muddy substrate erosion. HEB 3, with a total thickness up to 10 cm and an internal bipartite structure, is characterised by a basal massive sandstone sharply overlain by a muddy siltstone interval. The upper unit was probably deposited by cohesive debris flow...

Laser filament-induced aerosol formation

Directory of Open Access Journals (Sweden)

H. Saathoff

2013-05-01

Full Text Available Using the aerosol and cloud simulation chamber AIDA, we investigated the laser filament induced particle formation in ambient air, humid synthetic air, humid nitrogen, argon–oxygen mixture, and pure argon in order to simulate the particle formation under realistic atmospheric conditions as well as to investigate the influence of typical gas-phase atmospheric constituents on the particle formation. Terawatt laser plasma filaments generated new particles in the size range 3 to 130 nm with particle production rates ranging from 1 × 107 to 5 × 109 cm−3 plasma s−1 for the given experimental conditions. In all cases the particle formation rates increased exponentially with the water content of the gas mixture. Furthermore, the presence of a few ppb of trace gases like SO2 and α-pinene clearly enhanced the particle yield by number, the latter also by mass. Our findings suggest that new particle formation is efficiently supported by oxidized species like acids generated by the photoionization of both major and minor components of the air, including N2, NH3, SO2 and organics.

Automation of Tabular Application Formation

Directory of Open Access Journals (Sweden)

S. V. Zykin

2013-01-01

Full Text Available The paper considers automation problems of the interface formation between a table and a relational database. The task description is formalized and the description of the existing approaches to formation of data representations on an example of widely widespread CASE-tools is submitted. The definition of intermediate data representation as a ”join table” is offered, which is used for maintenance of correctness of data representation formation, and also is necessary for direct and inverse data transformations. On the basis of lossless join property and realized dependencies, the concept and a way of context formation of the application and restrictions is introduced. The considered material is further used for constructing an inverse data transformation from tabular presentation into a relational one. On the basis of relationships properties on a database scheme, the partial order on the relations is established, and the restriction of acyclic databases schemes is introduced. The received results are further used at the analysis of principles of formation of inverse data transformation, and the basic details of such a transformation algorithm are considered.

Decentralized Control for Scalable Quadcopter Formations

Directory of Open Access Journals (Sweden)

Qasim Ali

2016-01-01

Full Text Available An innovative framework has been developed for teamwork of two quadcopter formations, each having its specified formation geometry, assigned task, and matching control scheme. Position control for quadcopters in one of the formations has been implemented through a Linear Quadratic Regulator Proportional Integral (LQR PI control scheme based on explicit model following scheme. Quadcopters in the other formation are controlled through LQR PI servomechanism control scheme. These two control schemes are compared in terms of their performance and control effort. Both formations are commanded by respective ground stations through virtual leaders. Quadcopters in formations are able to track desired trajectories as well as hovering at desired points for selected time duration. In case of communication loss between ground station and any of the quadcopters, the neighboring quadcopter provides the command data, received from the ground station, to the affected unit. Proposed control schemes have been validated through extensive simulations using MATLAB®/Simulink® that provided favorable results.

Geologic Maps and Cross Sections of the Tuba City Open Dump Site and Vicinity, With Implications for the Occurrence and Flow of Ground Water

Science.gov (United States)

Otton, James K.; Johnson, Ray H.; Horton, Robert J.

2008-01-01

This report is designed to make available to interested parties geologic and limited hydrologic and geochemical information about the Tuba City Open Dump (TCOD) site. This information has been gathered during studies of the site from January to September 2008. Mapping by the authors and construction of cross sections show that a section of gently northeast-dipping Jurassic sedimentary rocks underlies the TCOD and vicinity. Low mesas in the area are capped by variably cemented gravels and siliceous limestones. Surficial sediments are composed of eolian sand and fluvially reworked eolian sand that overlie bedrock underneath the TCOD. Nearby Pasture Canyon is underlain by fluvial and floodplain sediment consisting of sand and silt. Shallow ground water of the water-table aquifer at the TCOD moves westward through the surficial sediment and the underlying weathered bedrock to Pasture Canyon then southward along the canyon. A fracture zone extends up the wash that passes just to the north of the TCOD and brings deeper ground water of the N-aquifer to the water-table aquifer. Bedrock consists of the Jurassic Navajo Sandstone composed of thick sections of eolian crossbedded sandstone with lesser laterally discontinuous layers of silty sandstone, siltstone, and limestone. Below the Navajo Sandstone is a section informally known as the Kayenta Formation-Navajo Sandstone transition zone. It is composed of calcareous sandstone, silty sandstone, siltstone, and limestone beds that intertongue with crossbedded sandstone. The finer grained rocks in both major bedrock units form aquitards that limit downward movement of ground water. The water-table aquifer is perched on these aquitards, which locally occurs beneath the two open dumps that form the TCOD site. A monocline occupies the position of Pasture Canyon west of the TCOD. Fractures likely related to the monocline are exposed in several localities. Deep ground waters consist of dilute calcium-bicarbonate waters low in all

Frequency formats, probability formats, or problem structure? A test of the nested-sets hypothesis in an extensional reasoning task

Directory of Open Access Journals (Sweden)

William P. Neace

2008-02-01

Full Text Available Five experiments addressed a controversy in the probability judgment literature that centers on the efficacy of framing probabilities as frequencies. The natural frequency view predicts that frequency formats attenuate errors, while the nested-sets view predicts that highlighting the set-subset structure of the problem reduces error, regardless of problem format. This study tested these predictions using a conjunction task. Previous studies reporting that frequency formats reduced conjunction errors confounded reference class with problem format. After controlling this confound, the present study's findings show that conjunction errors can be reduced using either a probability or a frequency format, that frequency effects depend upon the presence of a reference class, and that frequency formats do not promote better statistical reasoning than probability formats.

The NeXus data format.

Science.gov (United States)

Könnecke, Mark; Akeroyd, Frederick A; Bernstein, Herbert J; Brewster, Aaron S; Campbell, Stuart I; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R; Männicke, David; Osborn, Raymond; Peterson, Peter F; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

2015-02-01

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data.

Forces in strategy formation

DEFF Research Database (Denmark)

Steensen, Elmer Fly; Sanchez, Ron

2008-01-01

This chapter proposes that organizational strategy formation should be characterized theoretically as a process that is subject to several interacting forces, rather than represented by separate discrete decisionmodels or theoretic perspectives, as is commonly done in the strategic management...... literature. Based on an extensive review of relevant theory and empirical work in strategic decision-making, organizational change theory, cognitive and social psychology, and strategy processes, seven kinds of ''forces'' - rational, imposed, teleological, learning, political, heuristic, and social...... - are identified as interacting in and having significant influence on the strategy formation process. It is further argued that by applying a holistic ''forces-view'' of the significant and interacting influences on strategy formation, we can better understand the dynamics and challenges in managing the process...

New Particle Formation Study Final Campaign Report

Energy Technology Data Exchange (ETDEWEB)

Smith, JN; McMurry, PH [University of Minnesota

2015-01-01

The scientific foci of the New Particle Formation Study were the formation and evolution of atmospheric aerosols and the impacts of newly formed particles on cloud processes. Specifically, we planned to: (1) to identify the species and mechanisms responsible for the initial steps of new particle formation, i.e., the formation of thermodynamically stable clusters; (2) investigate the role of acid-base chemistry in new particle growth through measurements of ammonia and amines as well as organic and inorganic acids in both atmospheric nanoparticles and the gas phase; (3) investigate the contribution of other surface area or volume-controlled processes to nanoparticle formation and growth; (4) create a comprehensive dataset related to new particle formation and growth that can be used as input for our own thermodynamic models as well as the modeling efforts by our Department of Energy (DOE) Aerosol Life Cycle working group collaborators; (5) characterize the increase of the number and activity of cloud condensation nuclei (CCN) due to particle formation and growth; (6) determine the regional extent of new particle formation to address the role that atmospheric transport plays in determining the impacts, if any, of new particle formation on cloud number and properties.

Star Formation in Irregular Galaxies.

Science.gov (United States)

Hunter, Deidre; Wolff, Sidney

1985-01-01

Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

The relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation using Zymomonas mobilis 2716

Energy Technology Data Exchange (ETDEWEB)

Doelle, M.B.; Doelle, H.W. (Queensland Univ., St. Lucia (Australia). Dept. of Microbiology); Greenfield, P.F. (Queensland Univ., St. Lucia (Australia). Dept. of Chemical Engineering)

1990-11-01

Investigations into the relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation by Zymomonas mobilis 2716 revealed two distinct phenomena responsible for carbon flow diversion, a 'sucrose effect' and a 'salt effect'. Neither of the two phenomena affects sucrose hydrolysis, but they divert carbon flow of the fructose monomer leading to its own accumulation, sorbitol or oligosaccharide formation. Sucrose concentrations in excess of 15% (w/v) led to sorbitol formation, the level of which may exceed 2% (w/v) depending upon glucose accumulation during sucrose hydrolysis. Increasing mineral ion concentrations led initially to carbon losses and finally to fructose accumulation instead of sorbitol formation. This carbon loss can be corrected by the addition of invertase, which in turn leads to an increase in sorbitol, fructose and ethanol. Potassium and chloride are the dominant ions responsible for suppression of sorbitol formation and fructose uptake, encouraging oligosaccharide formation. These fructooligosaccharides must be of a type which can be converted to fructose, sorbitol and ethanol through the action of invertase. The requirement of invertase addition to prevent fructooligosaccharide formation is indirect evidence that Z. mobilis 2716 does not produce invertase. (orig.).

ENDF/B-5 formats manual 1984

Energy Technology Data Exchange (ETDEWEB)

Kinsey, R; Magurno, B A

1986-09-01

The ENDF-5 Format, originally the format of the US Evaluated Nuclear Data File ENDF/B-5, was internationally recommended for the computer storage, processing and exchange of evaluated neutron nuclear data. The present document contains the original Formats Manual of 1979, updated with revisions of Nov. 1983. (author) Figs, tabs

Stratigraphy and dissolution of the Rustler Formation

International Nuclear Information System (INIS)

Bachman, G.O.

1987-01-01

This report describes the physical stratigraphy of the Rustler Formation, because the Waste Isolation Pilot Plant will be constructed in salt beds that underlie this formation. Described are subdivisions of the formations, the major karst features, and a proposed method for the formation of Nash Draw. 2 refs., 2 figs

Star Formation in low mass galaxies

Science.gov (United States)

Mehta, Vihang

2018-01-01

Our current hierarchical view of the universe asserts that the large galaxies we see today grew via mergers of numerous smaller galaxies. As evidenced by recent literature, the collective impact of these low mass galaxies on the universe is more substantial than previously thought. Studying the growth and evolution of these low mass galaxies is critical to our understanding of the universe as a whole. Star formation is one of the most important ongoing processes in galaxies. Forming stars is fundamental to the growth of a galaxy. One of the main goals of my thesis is to analyze the star formation in these low mass galaxies at different redshifts.Using the Hubble UltraViolet Ultra Deep Field (UVUDF), I investigate the star formation in galaxies at the peak of the cosmic star formation history using the ultraviolet (UV) light as a star formation indicator. Particularly, I measure the UV luminosity function (LF) to probe the volume-averaged star formation properties of galaxies at these redshifts. The depth of the UVUDF is ideal for a direct measurement of the faint end slope of the UV LF. This redshift range also provides a unique opportunity to directly compare UV to the "gold standard" of star formation indicators, namely the Hα nebular emission line. A joint analysis of the UV and Hα LFs suggests that, on average, the star formation histories in low mass galaxies (~109 M⊙) are more bursty compared to their higher mass counterparts at these redshifts.Complementary to the analysis of the average star formation properties of the bulk galaxy population, I investigate the details of star formation in some very bursty galaxies at lower redshifts selected from Spitzer Large Area Survey with Hyper-Suprime Cam (SPLASH). Using a broadband color-excess selection technique, I identify a sample of low redshift galaxies with bright nebular emission lines in the Subaru-XMM Deep Field (SXDF) from the SPLASH-SXDF catalog. These galaxies are highly star forming and have

Standard exercise report format (SERF)

International Nuclear Information System (INIS)

Anon.

1995-01-01

This talk summarizes the reasons for the development of draft SERF the Standard Exercise Report Format used for reporting the results of emergency preparedness exercises, and gives a summary of the format and rational behind it

Heating systems for heating subsurface formations

Science.gov (United States)

Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

2011-04-26

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

Formation of topological defects

International Nuclear Information System (INIS)

Vachaspati, T.

1991-01-01

We consider the formation of point and line topological defects (monopoles and strings) from a general point of view by allowing the probability of formation of a defect to vary. To investigate the statistical properties of the defects at formation we give qualitative arguments that are independent of any particular model in which such defects occur. These arguments are substantiated by numerical results in the case of strings and for monopoles in two dimensions. We find that the network of strings at formation undergoes a transition at a certain critical density below which there are no infinite strings and the closed-string (loop) distribution is exponentially suppressed at large lengths. The results are contrasted with the results of statistical arguments applied to a box of strings in dynamical equilibrium. We argue that if point defects were to form with smaller probability, the distance between monopoles and antimonopoles would decrease while the monopole-to-monopole distance would increase. We find that monopoles are always paired with antimonopoles but the pairing becomes clean only when the number density of defects is small. A similar reasoning would also apply to other defects

Method for detecting and locating sand-producing zones in friable, unconsolidated sandstone formations of subterranean formations

International Nuclear Information System (INIS)

Sparlin, D.D.

1976-01-01

A sand-producing zone in a friable, unconsolidated sandstone formation traversed by a well bore is found by first introducing into the reservoir about 0.1--10 gallons of a radioactive mixture per foot of vertical formation being treated, the mixture containing about 0.1--1 lb of radioactive material per gallon of carrier fluid. A dispersing agent containing a deemulsifying surfactant may then be injected into the formation. The radioactivity in the well bore is recorded and the reservoir is returned to production. Another radioactivity log is run and a decrease in radioactivity indicates the location of the sand-producing portions of the formation

Formative Constructs Implemented via Common Factors

Science.gov (United States)

Treiblmaier, Horst; Bentler, Peter M.; Mair, Patrick

2011-01-01

Recently there has been a renewed interest in formative measurement and its role in properly specified models. Formative measurement models are difficult to identify, and hence to estimate and test. Existing solutions to the identification problem are shown to not adequately represent the formative constructs of interest. We propose a new two-step…

Seismic attributes and advanced computer algorithm to predict formation pore pressure: Qalibah formation of Northwest Saudi Arabia

Science.gov (United States)

Nour, Abdoulshakour M.

Oil and gas exploration professionals have long recognized the importance of predicting pore pressure before drilling wells. Pre-drill pore pressure estimation not only helps with drilling wells safely but also aids in the determination of formation fluids migration and seal integrity. With respect to the hydrocarbon reservoirs, the appropriate drilling mud weight is directly related to the estimated pore pressure in the formation. If the mud weight is lower than the formation pressure, a blowout may occur, and conversely, if it is higher than the formation pressure, the formation may suffer irreparable damage due to the invasion of drilling fluids into the formation. A simple definition of pore pressure is the pressure of the pore fluids in excess of the hydrostatic pressure. In this thesis, I investigated the utility of advance computer algorithm called Support Vector Machine (SVM) to learn the pattern of high pore pressure regime, using seismic attributes such as Instantaneous phase, t*Attenuation, Cosine of Phase, Vp/Vs ratio, P-Impedance, Reflection Acoustic Impedance, Dominant frequency and one well attribute (Mud-Weigh) as the learning dataset. I applied this technique to the over pressured Qalibah formation of Northwest Saudi Arabia. The results of my research revealed that in the Qalibah formation of Northwest Saudi Arabia, the pore pressure trend can be predicted using SVM with seismic and well attributes as the learning dataset. I was able to show the pore pressure trend at any given point within the geographical extent of the 3D seismic data from which the seismic attributes were derived. In addition, my results surprisingly showed the subtle variation of pressure within the thick succession of shale units of the Qalibah formation.

Consensus formation on coevolving networks: groups' formation and structure

International Nuclear Information System (INIS)

Kozma, Balazs; Barrat, Alain

2008-01-01

We study the effect of adaptivity on a social model of opinion dynamics and consensus formation. We analyse how the adaptivity of the network of contacts between agents to the underlying social dynamics affects the size and topological properties of groups and the convergence time to the stable final state. We find that, while on static networks these properties are determined by percolation phenomena, on adaptive networks the rewiring process leads to different behaviors: adaptive rewiring fosters group formation by enhancing communication between agents of similar opinion, though it also makes possible the division of clusters. We show how the convergence time is determined by the characteristic time of link rearrangement. We finally investigate how the adaptivity yields nontrivial correlations between the internal topology and the size of the groups of agreeing agents

Dioxin formation from waste incineration.

Science.gov (United States)

Shibamoto, Takayuki; Yasuhara, Akio; Katami, Takeo

2007-01-01

There has been great concern about dioxins-polychlorinated dibenzo dioxins (PCDDs), polychlorinated dibenzo furans (PCDFs), and polychlorinated biphenyls (PCBs)-causing contamination in the environment because the adverse effects of these chemicals on human health have been known for many years. Possible dioxin-contamination has received much attention recently not only by environmental scientists but also by the public, because dioxins are known to be formed during the combustion of industrial and domestic wastes and to escape into the environment via exhaust gases from incinerators. Consequently, there is a pressing need to investigate the formation mechanisms or reaction pathways of these chlorinated chemicals to be able to devise ways to reduce their environmental contamination. A well-controlled small-scale incinerator was used for the experiments in the core references of this review. These articles report the investigation of dioxin formation from the combustion of various waste-simulated samples, including different kinds of paper, various kinds of wood, fallen leaves, food samples, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride, polyethylene tetraphthalate (PET), and various kinds of plastic products. These samples were also incinerated with inorganic chlorides (NaCl, KCl, CuCI2, MgCl2, MnCl2, FeCl2, CoCl2, fly ash, and seawater) or organic chlorides (PVC, chlordane, and pentachlorophenol) to investigate the role of chlorine content and/or the presence of different metals in dioxin formation. Some samples, such as newspapers, were burned after they were impregnated with NaCl or PVC, as well as being cocombusted with chlorides. The roles of incineration conditions, including chamber temperatures, O2 concentrations, and CO concentrations, in dioxin formation were also investigated. Dioxins (PCDDs, PCDFs, and coplanar-PCBs) formed in the exhaust gases from a controlled small-scale incinerator, where experimental waste

Teacher perspectives about using formative assessment

DEFF Research Database (Denmark)

Evans, Robert Harry; Clesham, Rose; Dolin, Jens

2018-01-01

This chapter examines three different classroom teacher perspectives when using ASSIST-ME project formative assessment methods as described in the introductory chapter. The first ‘teacher perspective’ is about changes in teacher self-efficacies while using formative assessment methods as monitored...... by a pre- and post-teacher questionnaire. Teachers who tried the unfamiliar formative methods of assessment (see introductory book chapter for these methods) as well as their colleagues who did not were surveyed. The second ‘teacher perspective’ examines changes in teachers’ subjective theories while...... trying project-specific formative assessment methods in Czech Republic. Analyses are done through case studies and interviews. The final part of the chapter looks at teacher perspectives while using an Internet-based application to facilitate formative assessment. The teacher use of the application...

COMPETENCYTHE FORMATION FOR LIFE

Directory of Open Access Journals (Sweden)

Milagros Mederos-Piñeiro

2016-07-01

Full Text Available The formation of life competences is the result of a quality education that prepares students to meet the challenges of a fast moving world where equality and equal opportunities should constitute premises of education; training them is a challenge teachers to assume new generations contribute actively to a better world. In Cuba are important research on the formation of communication competences and self-regulated learning in primary school. The paper shows the result of an investigation that provides a methodology for the formation of life competences in primary school education, used as an essential pathway research activity. The methodological approach of research has a quantitative approach and an explanatory scope to establish and make sense of understanding the causal relationship between the direction of research activity and training of life competences. Theoretical, empirical and mathematical-statistical, for characterizing the initial state, processing of results and analysis: research methods are used. The application of the methodology for the formation of life competences makes teachers lead the teaching-learning process with a research and transforming teaching concept, where the school is the protagonist of their learning and causes changes in their performances, which are evident in the formed competences related to effective and affective communication; the solution of problems related to life; the use of means in obtaining the knowledge and the expression of a behavior consistent with school and social demands. The effectiveness of the methodology confirms that there is a causal relationship between the direction of research activity by teachers and the formation of life competences in school.

The Physics of Planetesimal Formation

Science.gov (United States)

Simon, Jacob; Armitage, Philip; Youdin, Andrew; Li, Rixin

2015-12-01

Planetesimals are the precursors to planets, and understanding their formation is an essential step towards developing a complete theory of planet formation. For small solid particles (e.g., dust grains) to coagulate into planetesimals, however, requires that these particles grow beyond centimeter sizes; with traditional coagulation physics, this is very difficult. The streaming instability, which is a clumping process akin to the pile-up of cars in a traffic jam, generates sufficiently high solid densities that the mutual gravity between the clumped particles eventually causes their collapse towards planetesimal mass and size scales. Exploring this transition from dust grains to planetesimals is still in its infancy but is extremely important if we want to understand the basics of planet formation. Here, I present a series of high resolution, first principles numerical simulations of potoplanetary disk gas and dust to study the clumping of particles via the streaming instability and the subsequent collapse towards planetesimals. These simulations have been employed to characterize the planetesimal population as a function of radius in protoplanetary disks. The results of these simulations will be crucial for planet formation models to correctly explain the formation and configuration of solar systems.

Formation of galaxies

International Nuclear Information System (INIS)

Szalay, A.S.

1984-12-01

The present theories of galaxy formation are reviewed. The relation between peculiar velocities and the correlation function of galaxies points to the possibility that galaxies do not form uniformly everywhere. Scale invariant properties of the cluster-cluster correlations are discussed. Comparing the correlation functions in a dimensionless way, galaxies appear to be stronger clustered, in contrast with the comparison of the dimensional amplitudes of the correlation functions. Theoretical implications of several observations as Lyman-α clouds, correlations of faint galaxies are discussed. None of the present theories of galaxy formation can account for all facts in a natural way. 29 references

Formation temperatures of thermogenic and biogenic methane

Science.gov (United States)

Stolper, D.A.; Lawson, M.; Davis, C.L.; Ferreira, A.A.; Santos Neto, E. V.; Ellis, G.S.; Lewan, M.D.; Martini, Anna M.; Tang, Y.; Schoell, M.; Sessions, A.L.; Eiler, J.M.

2014-01-01

Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models.

Process for fracturing underground formations

Energy Technology Data Exchange (ETDEWEB)

Kiel, O M

1974-01-25

This invention concerns a process for fracturing underground formations and has as one object the mixing of viscous compositions. Through a borehole, a fluid is injected into the formation. This fluid contains a complex prepared by the reaction of an aliphatic quaternary ammonium compound with a water-soluble compound chosen from monosaccharides, disaccharides, trisaccharides, polysaccharides, and synthetic hydroxylated polymers with long chains. These complexes are formed at temperatures between 20/sup 0/ and 205/sup 0/C. The process also includes production of formation fluid into the borehole.

AGN feedback in galaxy formation

CERN Document Server

Antonuccio-Delogu, Vincenzo

2010-01-01

During the past decade, convincing evidence has been accumulated concerning the effect of active galactic nuclei (AGN) activity on the internal and external environment of their host galaxies. Featuring contributions from well-respected researchers in the field, and bringing together work by specialists in both galaxy formation and AGN, this volume addresses a number of key questions about AGN feedback in the context of galaxy formation. The topics covered include downsizing and star-formation time scales in massive elliptical galaxies, the connection between the epochs of supermassive black h

Improving the Formatting Tools of CDS Invenio

CERN Document Server

Caffaro, J; Pu Faltings, Pearl

2006-01-01

CDS Invenio is the web-based integrated digital library system developed at CERN. It is a strategical tool that supports the archival and open dissemination of documents produced by CERN researchers. This paper reports on my Master’s thesis work done on BibFormat, a module in CDS Invenio, which formats documents metadata. The goal of this project was to implement a completely new formatting module for CDS Invenio. In this report a strong emphasis is put on the user-centered design of the new BibFormat. The bibliographic formatting process and its requirements are discussed. The task analysis and its resulting interaction model are detailed. The document also shows the implemented user interface of BibFormat and gives the results of the user evaluation of this interface. Finally the results of a small usability study of the formats included in CDS Invenio are discussed.

Formative (measurement)

NARCIS (Netherlands)

Fassott, G.; Henseler, Jörg; Cooper, C.; Lee, N.; Farrell, A.

2015-01-01

When using measurement models with multiple indicators, researchers need to decide about the epistemic relationship between the latent variable and its indicators. In this article, we describe the nature, the estimation, the characteristics, and the validity assessment of formative measurement

FORMATIVE ASSESSMENT IN EFL CLASSROOM PRACTICES

Directory of Open Access Journals (Sweden)

Ida Ayu Made Sri Widiastuti

2017-03-01

Full Text Available This study investigated the challenges and opportunities of formative assessment in EFL classes. It made use of qualitative research design by using indepth interviews to collect the required data. Three teachers and three students were involved as research participants in this study and they were intensively interviewed to get valid and reliable data regarding their understanding of formative assessment and the follow up actions they took after implementing formative assessment. The results of this study showed that the English teachers were found not to take appropriate follow up actions due to their low understanding of formative assessment. The teachers’ understanding could influence their ability in deciding the actions. This study indicates that EFL teachers need urgent further intensive training on the appropriate implementation of formative assessment and how follow up actions should be integrated into classroom practices

Formation Control for the MAXIM Mission

Science.gov (United States)

Luquette, Richard J.; Leitner, Jesse; Gendreau, Keith; Sanner, Robert M.

2004-01-01

Over the next twenty years, a wave of change is occurring in the space-based scientific remote sensing community. While the fundamental limits in the spatial and angular resolution achievable in spacecraft have been reached, based on today s technology, an expansive new technology base has appeared over the past decade in the area of Distributed Space Systems (DSS). A key subset of the DSS technology area is that which covers precision formation flying of space vehicles. Through precision formation flying, the baselines, previously defined by the largest monolithic structure which could fit in the largest launch vehicle fairing, are now virtually unlimited. Several missions including the Micro-Arcsecond X-ray Imaging Mission (MAXIM), and the Stellar Imager will drive the formation flying challenges to achieve unprecedented baselines for high resolution, extended-scene, interferometry in the ultraviolet and X-ray regimes. This paper focuses on establishing the feasibility for the formation control of the MAXIM mission. MAXIM formation flying requirements are on the order of microns, while Stellar Imager mission requirements are on the order of nanometers. This paper specifically addresses: (1) high-level science requirements for these missions and how they evolve into engineering requirements; and (2) the development of linearized equations of relative motion for a formation operating in an n-body gravitational field. Linearized equations of motion provide the ground work for linear formation control designs.

DNA methylation and memory formation.

Science.gov (United States)

Day, Jeremy J; Sweatt, J David

2010-11-01

Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.

Robust Decentralized Formation Flight Control

Directory of Open Access Journals (Sweden)

Zhao Weihua

2011-01-01

Full Text Available Motivated by the idea of multiplexed model predictive control (MMPC, this paper introduces a new framework for unmanned aerial vehicles (UAVs formation flight and coordination. Formulated using MMPC approach, the whole centralized formation flight system is considered as a linear periodic system with control inputs of each UAV subsystem as its periodic inputs. Divided into decentralized subsystems, the whole formation flight system is guaranteed stable if proper terminal cost and terminal constraints are added to each decentralized MPC formulation of the UAV subsystem. The decentralized robust MPC formulation for each UAV subsystem with bounded input disturbances and model uncertainties is also presented. Furthermore, an obstacle avoidance control scheme for any shape and size of obstacles, including the nonapriorily known ones, is integrated under the unified MPC framework. The results from simulations demonstrate that the proposed framework can successfully achieve robust collision-free formation flights.

Formation of tax culture in Russia

Directory of Open Access Journals (Sweden)

Halikova Je.A.

2014-11-01

Full Text Available This article deals with the mechanism of the formation of tax culture in Russia, moral and ethical principles, on which based the work of the tax authorities, given the author's idea of the formation of tax culture. We consider the institution of tax advice, its interaction with the tax authorities and its impact on the formation of tax culture.

Making the invisible visible: improved electrospray ion formation of metalloporphyrins/-phthalocyanines by attachment of the formate anion (HCOO(-)).

Science.gov (United States)

Hitzenberger, Jakob Felix; Dammann, Claudia; Lang, Nina; Lungerich, Dominik; García-Iglesias, Miguel; Bottari, Giovanni; Torres, Tomás; Jux, Norbert; Drewello, Thomas

2016-02-21

A protocol is developed for the coordination of the formate anion (HCOO(-)) to neutral metalloporphyrins (Pors) and -phthalocyanines (Pcs) containing divalent metals as a means to improve their ion formation in electrospray ionization (ESI). This method is particularly useful when the oxidation of the neutral metallomacrocycle fails. While focusing on Zn(II)Pors and Zn(II)Pcs, we show that formate is also readily attached to Mn(II), Mg(II) and Co(II)Pcs. However, for the Co(II)Pc secondary reactions can be observed. Upon collision-induced dissociation (CID), Zn(II)Por/Pc·formate supramolecular complexes can undergo the loss of CO2 in combination with transfer of a hydride anion (H(-)) to the zinc metal center. Further dissociation leads to electron transfer and hydrogen atom loss, generating a route to the radical anion of the Zn(II)Por/Pc without the need for electrochemical reduction, although the Zn(II)Por/Pc may have a too low electron affinity to allow electron transfer directly from the formate anion. In addition to single Por molecules, multi Por arrays were successfully analyzed by this method. In this case, multiple addition of formate occurs, giving rise to multiply charged species. In these multi Por arrays, complexation of the formate anion occurs by two surrounding Por units (sandwich). Therefore, the maximum attainment of formate anions in these arrays corresponds to the number of such sandwich complexes rather than the number of porphyrin moieties. The same bonding motif leads to dimers of the composition [(Zn(II)Por/Pc)2·HCOO](-). In these, the formate anion can act as a structural probe, allowing the distinction of isomeric ions with the formate bridging two macrocycles or being attached to a dimer of directly connected macrocycles.

Maggot excretions inhibit biofilm formation on biomaterials.

Science.gov (United States)

Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

2010-10-01

Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

Method of developing thick sloping coal formations

Energy Technology Data Exchange (ETDEWEB)

Bragintsev, V F; Mashkovtsev, I L; Semenov, V S; Zykov, V N

1980-04-25

A method is patented for developing thick sloping coal formations in 3 inclined layers. It includes conducting developmental operations for each of the layers until one begins the last one and extraction of the layers. In order to improve effectivess and extraction operation safety one first carried out preliminary development of a formation in thin strips beneath protected objects when extracting formation which contain alot of gas. Then one removes the gas of a formation through boreholes that have been drilled into the formation from the indicated workings. Then one works the upper layer in thin strips in a sequence from the roof of the formation to the floor of the upper layer. The one strengthens roof rock of the formation by pumping in a quickly hardening solution into the boreholes which have been drilled into the roof of the formation after processing the upper layer. The middle layer is worked in thin strips in the sequence from the roof to the ground of the middle layer, then the lower layer of the formation is strengthened by pumping in quickly hardening solution into the formation along degasified boreholes and it is worked in thin strips in sequence from the ground of the lower to its roof. Workings are shaped respectively for the middle and lower layers by deepening workings of the upper and middle layers. The layers are worked respectively after finishing displacement of the roof in front of the extraction face of each subsequent extraction of a layer in alternating fashion.

Insights from simulations of star formation

International Nuclear Information System (INIS)

Larson, Richard B

2007-01-01

Although the basic physics of star formation is classical, numerical simulations have yielded essential insights into how stars form. They show that star formation is a highly nonuniform runaway process characterized by the emergence of nearly singular peaks in density, followed by the accretional growth of embryo stars that form at these density peaks. Circumstellar discs often form from the gas being accreted by the forming stars, and accretion from these discs may be episodic, driven by gravitational instabilities or by protostellar interactions. Star-forming clouds typically develop filamentary structures, which may, along with the thermal physics, play an important role in the origin of stellar masses because of the sensitivity of filament fragmentation to temperature variations. Simulations of the formation of star clusters show that the most massive stars form by continuing accretion in the dense cluster cores, and this again is a runaway process that couples star formation and cluster formation. Star-forming clouds also tend to develop hierarchical structures, and smaller groups of forming objects tend to merge into progressively larger ones, a generic feature of self-gravitating systems that is common to star formation and galaxy formation. Because of the large range of scales and the complex dynamics involved, analytic models cannot adequately describe many aspects of star formation, and detailed numerical simulations are needed to advance our understanding of the subject. 'The purpose of computing is insight, not numbers.' Richard W Hamming, in Numerical Methods for Scientists and Engineers (1962) 'There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.' William Shakespeare, in Hamlet, Prince of Denmark (1604) (key issues review)

Insights from simulations of star formation

Energy Technology Data Exchange (ETDEWEB)

Larson, Richard B [Department of Astronomy, Yale University, Box 208101, New Haven, CT 06520-8101 (United States)

2007-03-15

Although the basic physics of star formation is classical, numerical simulations have yielded essential insights into how stars form. They show that star formation is a highly nonuniform runaway process characterized by the emergence of nearly singular peaks in density, followed by the accretional growth of embryo stars that form at these density peaks. Circumstellar discs often form from the gas being accreted by the forming stars, and accretion from these discs may be episodic, driven by gravitational instabilities or by protostellar interactions. Star-forming clouds typically develop filamentary structures, which may, along with the thermal physics, play an important role in the origin of stellar masses because of the sensitivity of filament fragmentation to temperature variations. Simulations of the formation of star clusters show that the most massive stars form by continuing accretion in the dense cluster cores, and this again is a runaway process that couples star formation and cluster formation. Star-forming clouds also tend to develop hierarchical structures, and smaller groups of forming objects tend to merge into progressively larger ones, a generic feature of self-gravitating systems that is common to star formation and galaxy formation. Because of the large range of scales and the complex dynamics involved, analytic models cannot adequately describe many aspects of star formation, and detailed numerical simulations are needed to advance our understanding of the subject. 'The purpose of computing is insight, not numbers.' Richard W Hamming, in Numerical Methods for Scientists and Engineers (1962) 'There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.' William Shakespeare, in Hamlet, Prince of Denmark (1604) (key issues review)

Galaxy formation and evolution

CERN Document Server

Mo, Houjun; White, Simon

2010-01-01

The rapidly expanding field of galaxy formation lies at the interface between astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual chapters explore the evolution of the Universe as a whole and its particle and radiation content; linear and nonlinear growth of cosmic structure; processes affecting the gaseous and dark matter components of galaxies and their stellar populations; the formation of spiral and elliptical galaxies; central supermassive black holes and the activity associated with them; galaxy interactions; and the intergalactic medium. Emphasizing both observational and theoretical aspects, this book provides a coherent introduction for astronomers, cosmologists, and astroparticle physicists to the broad range of science underlying the formation and evolution of galaxies.

Output formatting in Apple-Soft Basic

International Nuclear Information System (INIS)

Navale, A.S.

1987-01-01

Personal computers are being used extensively in various fields. BASIC is a very popular and widely used language in personal computers. Apple computer is one of the popular machines used for scientific and engineering applications. Presenting output from computers in a neat and easy to read form is very important. Languages like FORTRAN have utility command 'FORMAT' which takes care of the formatting of the output in user-defined form. In some versions of BASIC a PRINT USING facility is available but it is not as powerful as the FORTRAN statement 'FORMAT'. Applesoft basic does not have even this PRINT USING command. Programmers have to write their own program segments to handle output formatting in Applesoft BASIC. Generally, such user written programs are of limited use as they cannot be used easily with other programs. A general purpose and easily transportable subroutine in Applesoft BASIC is presented here for handling output formatting in user-defined structure. The subroutine is nearly as powerful as the FORMAT statement in FORTRAN. It can also be used in other versions of BASIC with very little modifications. 3 tables, 4 refs. (author)

Heating tar sands formations while controlling pressure

Science.gov (United States)

Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

2010-01-12

Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

Formation of the oil composition of the Yu0 Bazhenov formation, Salym oil field

Directory of Open Access Journals (Sweden)

E.V. Soboleva

2017-05-01

Full Text Available The Bazhenov horizon of Western Siberia has been studied in considerable detail from different perspectives and different methods, a large number of studies have been devoted to a wide range of issues related to the lithological composition of rocks, their reservoir properties, the study of organic matter, properties and composition of oil at various analytical levels, and many others. This work is devoted to restoring conditions for the formation of oil properties and composition of the Yu0 Salym oil field, based mainly on the geochemical aspects of the study of oil changes both in area and in the section within the productive layer of Salym structure, using some geological data, such as structural plan for the reflecting horizon B (the roof of the Bazhenov formation, having a complex configuration, reservoir temperatures and pressure, well flow rates, and others. There is no single reservoir at the Salym field in the Yu0 formation. For the conclusions of the geological-geochemical interpretation, a sampling of 61 samples of oil from exploration, appraisal and production wells of the initial stages of production was used, since in the future when oil is extracted, the ecology in the deposits changes, and 21 samples of oil from other fields in the West Siberian oil and gas basin. Conventionally, three types of oils are distinguished, differing in their physicochemical parameters, group hydrocarbon and molecular composition. It was suggested that in addition to the own organic matter of the Bazhenov formation, hydrocarbon fluids of the Vasyugan, Tyumen formations and possibly Paleozoic rocks were involved in the formation of the oil composition. The flow of light liquid hydrocarbons and gases occurred along the zones of faults of different genesis and duration of existence.

Jacutingait, paladiové zlato a Pd-selenidy v Cu-zrudnění z karbonských sedimentů od Košťálova u Semil (podkrkonošská pánev)

Czech Academy of Sciences Publication Activity Database

Malec, J.; Veselovský, F.; Böhmová, Vlasta; Prouza, V.

2012-01-01

Roč. 2011, podzim (2012), s. 189-192 ISSN 0514-8057 Institutional research plan: CEZ:AV0Z30130516 Keywords : jacutingaite * Pd-gold * Pd-selenide * silver * chalcodite s. l. * analyses of ore elements * siltstone * Upper Carboniferous * Krkonoše Piedmont Bassin (Czech Republic) Subject RIV: DB - Geology ; Mineralogy http://www.geology.cz/zpravy/obsah/2011/zpravy_2011-43.pdf

Use of geophysical methods for determination of physico-mechanical properties of coal-bearing rocks in wells of the Vorkutskoye field

International Nuclear Information System (INIS)

Grechukhin, V.V.; Iokhin, S.B.; Baklanov, V.G.; Chernikov, A.G.

1974-01-01

The total porosity (P), electric resistivity (Er), density, bulk density, water content, velocity of longitudinal elastic waves (Vl), intensity of natural γ-radiation, and polarization self-potential (Ps) are determined of the lithol. different interlayered sandstones, argillites, mudstones, siltstones, and concretions. A direct linear correlation exists between these parameters and the mineralogical composition, coefficient of sorting, and sedimentation conditions

Geology and sratigraphy of the Cainozoic Sedimantary Rocks in the Kale-Kurbalık Area, Denizli, Southwestern Turkey

Directory of Open Access Journals (Sweden)

H.Yavuz HAKYEMEZ

1989-06-01

Full Text Available In this work, the geological and stratigraphical characteristics of the Cainozoic sedimentary rocks exposed at the Kale-Kurbalık (SW Denizli area have been investigated. In the study area the Palaeozoic and Mesozoic rocks form the basement rocks and are overlain by the Oligocene to the Quaternary aged sedimentary rocks. The Tertiary rocks have been considered in two groups, namely the Akçay group and the Muğla group. The Oligocene to the Burdigalian aged Akçay group is represented by the Karadere, Mortuma, Yenidere, Künar and Kale formations. During this time interval, mostly the terrestrial fine and coarse clastics were deposited, but in the last stage of this time shallow marine carbonates were sedimented on the some parts of the region. There is an angular unconformity between the Mortuma and the Yenidere formations of the Akçay group; others are conformable to each other. The Akçay group is 4100 meter thick. The Upper Astarasian (Middle Miocene to Pliocene aged Muğla group which overlies the Akçay group uncorformably is formed of the Sekköy, Yatağan and Milet formations. During this time interval, the lacustrine siltstones and carbonates and the terrestrial coarse elastics were deposited. The formations of the Muğla group are conformable and gradational to each other. The Muğla group is 550 meter thick. The Quaternary deposits have been considered in two units, namely "Lower" and "Upper" Quaternary sediments. Only the Mortuma formation of all units of the study area is gently folded, but others have low degree dips. Tectonic activity has played a big important role in the forming of the various sedimentary basins which have been generated since the beginning of the Oligocene up to the present.

The Road to Galaxy Formation

CERN Document Server

Keel, William C

2007-01-01

The formation of galaxies is one of the greatest puzzles in astronomy, the solution is shrouded in the depths of space and time, but has profound implications for the universe we observe today. The book discusses the beginnings of the process from cosmological observations and calculations, considers the broad features of galaxies that we need to explain and what we know of their later history. The author compares the competing theories for galaxy formation and considers the progress expected from new generations of powerful telescopes both on earth and in space. In this second edition the author has retained the observationally-based approach of the first edition, a feature which was particularly well-reviewed: Writing in Nature, Carlton Baugh noted in February 2003 that “It is refreshing, in a market dominated by theorists, to come across a book on galaxy formation written from an observational perspective. The Road to Galaxy Formation should prove to be a handy primer on observations for graduate student...

Formation aux TICE des formateurs d’enseignants : un tissage entre formation et autoformation

Directory of Open Access Journals (Sweden)

Pierre-François Coen

2012-01-01

Full Text Available Cette recherche exploratoire rend compte des modalités de formation des formateurs d’enseignants dans deux établissements d’enseignement du canton de Fribourg, en Suisse. Neuf formateurs d’enseignants ont été interrogés sur leurs parcours de formation et d’autoformation en matière de compétences technologiques et d’intégration des TICE. Les résultats montrent que, même si ces formateurs ont acquis des compétences technologiques, les dispositifs d’enseignement-apprentissage qu’ils mettent en place pour former de futurs enseignants intègrent relativement peu les TICE. En outre, les propos tenus montrent que les formateurs déploient des stratégies d’autoformation plus ou moins efficaces et coûteuses en temps pour les aspects techniques, mais n’usent presque jamais de ce type de procédé pour développer une intégration pédagogique des TICE dans leurs cours. La fin de l’article reprend ces éléments et les discute en essayant de présenter quelques pistes en articulant formation formelle et informelle dans le contexte de la formation des enseignants.

The Impact of Host Rock Geochemistry on Bacterial Community Structure in Oligotrophic Cave Environments.

Directory of Open Access Journals (Sweden)

Hazel A. Barton

2007-07-01

Full Text Available Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In order to assess whether microbial activity was leading to changes in the bedrock at each location, the samples were also examined by petrology, X-ray diffraction (XRD and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX. Our results suggest that on the chemically complex Yates Formation (sF88, the microbial community was significantly more diverse than on the limestone surfaces of the Capitan (WF1, despite a higher total number of cells on the latter. Further, the broader diversity of bacterial species at sF88 reflected a larger range of potential metabolic capabilities, presumably due to opportunities to use ions within the rock as nutrients and for chemolithotrophic energy production. The use of these ions at sF88 is supported by the formation of a corrosion residue, presumably through microbial scavenging activities. Our results suggest that rock fabric and mineralogy may be an important driver of ecosystem function and should be carefully reviewed when carrying out microbial community analysis in cave environments.

Processes and problems in secondary star formation

International Nuclear Information System (INIS)

Klein, R.I.; Whitaker, R.W.; Sandford, M.T. II.

1984-03-01

Recent developments relating the conditions in molecular clouds to star formation triggered by a prior stellar generation are reviewed. Primary processes are those that lead to the formation of a first stellar generation. The secondary processes that produce stars in response to effects caused by existing stars are compared and evaluated in terms of the observational data presently available. We discuss the role of turbulence to produce clumpy cloud structures and introduce new work on colliding inter-cloud gas flows leading to non-linear inhomogeneous cloud structures in an intially smooth cloud. This clumpy morphology has important consequences for secondary formation. The triggering processes of supernovae, stellar winds, and H II regions are discussed with emphasis on the consequences for radiation driven implosion as a promising secondary star formation mechanism. Detailed two-dimensional, radiation-hydrodynamic calculations of radiation driven implosion are discussed. This mechanism is shown to be highly efficient in synchronizing the formation of new stars in congruent to 1-3 x 10 4 years and could account for the recent evidence for new massive star formation in several UCHII regions. It is concluded that, while no single theory adequately explains the variety of star formation observed, a uniform description of star formation is likely to involve several secondary processes. Advances in the theory of star formation will require multiple dimensional calculations of coupled processes. The important non-linear interactions include hydrodynamics, radiation transport, and magnetic fields

Processes and problems in secondary star formation

International Nuclear Information System (INIS)

Klein, R.I.; Whitaker, R.W.; Sandford, M.T. II

1985-01-01

Recent developments relating the conditions in molecular clouds to star formation triggered by a prior stellar generation are reviewed. Primary processes are those that lead to the formation of a first stellar generation. The secondary processes that produce stars in response to effects caused by existing stars are compared and evaluated in terms of observational data presently available. We discuss the role of turbulence to produce clumpy cloud structures and introduce new work on colliding intercloud gas flows leading to nonlinear inhomogeneous cloud structures in an initially smooth cloud. This clumpy morphology has important consequences for secondary formation. The triggering processes of supernovae, stellar winds, and H II regions are discussed with emphasis on the consequences for radiation-driven implosion as a promising secondary star formation mechanism. Detailed two-dimensional, radiation-hydrodynamic calculations of radiation-driven implosion are discussed. This mechanism is shown to be highly efficient in synchronizing the formation of new stars in -- 1-3 x 10/sup 4/ yr and could account for the recent evidence for new massive star formation in several ultracompact H II regions. It is concluded that, while no single theory adequately explains the variety of star formation observed, a uniform description of star formation is likely to involve several secondary processes. Advances in the theory of star formation will require multi-dimensional calculations of coupled processes. Important nonlinear interactions include hydrodynamics, radiation transport, and magnetic fields

Professional Development through Formative Evaluation

Science.gov (United States)

Nsibande, Rejoice; Garraway, James

2011-01-01

Formative evaluation and its associated methodology of reflection on practice are used extensively in academic staff development. In reflecting on formative evaluation processes in both more traditional and newer programmes conducted at a university of technology, a number of variables reported in the literature were observed to have influenced…

Analysis of constituents of earth formations

International Nuclear Information System (INIS)

Hertzog, R.C.; Grau, J.A.

1981-01-01

The composition of an earth formation is investigated by repetitively irradiating the formation with bursts of neutrons from a source and measuring an energy spectrum of the scattering gamma rays resulting from such irradiation e.g. by photomultiplier or solid state detector. The measured spectrum is thereafter analyzed by comparing it with a composite spectrum, made up of standard spectra, measured in a controlled environment, of constituents postulated to comprise the formation. As a result of such analysis, the proportions of the postulated constituents in the formation are determined. Since the measured spectrum is subject to degradation due to changes in the resolution of the detector, a filtering arrangement effects modification of the standard spectra in a manner which compensates for the changes in the detector and thereby provides for a more accurate determination of the constituents of the formation. Temperature is measured by sensor to compensate for temperature dependence of detector resolution. (author)

Transient Exciplex Formation Electron Transfer Mechanism

OpenAIRE

Michael G. Kuzmin; Irina V. Soboleva; Elena V. Dolotova

2011-01-01

Transient exciplex formation mechanism of excited-state electron transfer reactions is analyzed in terms of experimental data on thermodynamics and kinetics of exciplex formation and decay. Experimental profiles of free energy, enthalpy, and entropy for transient exciplex formation and decay are considered for several electron transfer reactions in various solvents. Strong electronic coupling in contact pairs of reactants causes substantial decrease of activation energy relative to that for c...

Regulation of Reactionary Dentine Formation.

Science.gov (United States)

Neves, V C M; Sharpe, P T

2018-04-01

During the treatment of dental caries that has not penetrated the tooth pulp, maintenance of as much unaffected dentine as possible is a major goal during the physical removal of decayed mineral. Damage to dentine leads to release of fossilized factors (transforming growth factor-β [TGF-β] and bone morphogenic protein [BMP]) in the dentine that are believed to stimulate odontoblasts to secrete new "tertiary" dentine (reactionary dentine). This is formed on the pulpal surface of existing dentine and rethickens the dentine. We have previously shown that activation of Wnt/β-catenin signaling is pivotal for tooth repair in exposed pulp injury, and the pathway can be activated by small-molecule GSK-3 antagonists, resulting in enhanced reparative dentine formation. Here, we use a nonexposed pulp injury model to investigate the mechanisms of reactionary dentine formation in vivo, using small molecules to modulate the Wnt/β-catenin, TGF-β, and BMP pathways. We found that a local increase of Wnt activation at the injury site enhances reactionary dentine secretion. In addition, inhibition of TGF-β, BMP, or Wnt pathways does not impede reactionary dentine formation, although inhibition of TGF-β and/or BMP signaling does result in more disorganized, nontubular reactionary dentine. This suggests that Wnt/β-catenin signaling plays no major role in the formation of reactionary dentine, but in common with reparative dentine formation, exogenous elevation of Wnt/β-catenin signaling can enhance tertiary dentine formation. Release of latent TGF-β or BMPs from dentine is not required for the deposition of mineral to form reactionary dentine but does play a role in its organization.

Airborne gamma-ray spectrometer and magnetometer survey, Salem quadrangle (Oregon). Final report

International Nuclear Information System (INIS)

1981-01-01

Five uranium anomalies meet the minimum statistical requirements as defined in Volume I. These anomalies are tabulated and are shown on the Uranium Anomaly Interpretation Map. Potassium (%K), equivalent Uranium (ppM eU), equivalent Thorium (eT), eU/eT, eU/K, eT/K, and magnetic pseudo-contour maps are presented in Appendix E. Stacked Profiles showing geologic strip maps along each flight-line, together with sensor data, and ancillary data are presented in Appendix F. All maps and profiles were prepared on a scale of 1:250,000, but have been reduced to 1:500,000 for presentation in Volume II. Each of the anomalies occurs over the Eocene Tyee and Burpee formation (Teme), a rhythmically banded, feldspathic and micaceous, massive bedded sandstone, and siltstone. Anomalies 1, 2, 3, and 4 are in the northwest corner of the map. Anomalies 2 and 3 are near faults, so may be due to radon leaking from the faults. Anomaly No. 5 is in the southwest corner of the map

{alpha}-Man monolayer formation via Si-C bond formation and protein recognition

Energy Technology Data Exchange (ETDEWEB)

Funato, Koji [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan); Shirahata, Naoto [National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Miura, Yoshiko, E-mail: miuray@jaist.ac.j [School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292 (Japan)

2009-11-30

An acetylenyl-terminated saccharide was synthesized and the thin layer formation on the hydrogen-terminated silicon was investigated. The acetylenyl-terminated saccharide was synthesized by the condensation reaction of hexynoic acid and p-aminophenyl saccharide. This was reacted with hydrogen-terminated silicon (Si-H) by a photochemical reaction. The resulting saccharide modified substrate was analyzed by ellipsometry and X-ray photoelectron spectroscopy, which showed the formation of a uniform monolayer. The surface's ability to recognize proteins was analyzed by fluorescent microscopy, and showed specific interactions with sugar recognition proteins.

Inside-out planet formation

International Nuclear Information System (INIS)

Chatterjee, Sourav; Tan, Jonathan C.

2014-01-01

The compact multi-transiting planet systems discovered by Kepler challenge planet formation theories. Formation in situ from disks with radial mass surface density, Σ, profiles similar to the minimum mass solar nebula but boosted in normalization by factors ≳ 10 has been suggested. We propose that a more natural way to create these planets in the inner disk is formation sequentially from the inside-out via creation of successive gravitationally unstable rings fed from a continuous stream of small (∼cm-m size) 'pebbles', drifting inward via gas drag. Pebbles collect at the pressure maximum associated with the transition from a magnetorotational instability (MRI)-inactive ('dead zone') region to an inner MRI-active zone. A pebble ring builds up until it either becomes gravitationally unstable to form an ∼1 M ⊕ planet directly or induces gradual planet formation via core accretion. The planet may undergo Type I migration into the active region, allowing a new pebble ring and planet to form behind it. Alternatively, if migration is inefficient, the planet may continue to accrete from the disk until it becomes massive enough to isolate itself from the accretion flow. A variety of densities may result depending on the relative importance of residual gas accretion as the planet approaches its isolation mass. The process can repeat with a new pebble ring gathering at the new pressure maximum associated with the retreating dead-zone boundary. Our simple analytical model for this scenario of inside-out planet formation yields planetary masses, relative mass scalings with orbital radius, and minimum orbital separations consistent with those seen by Kepler. It provides an explanation of how massive planets can form with tightly packed and well-aligned system architectures, starting from typical protoplanetary disk properties.

Recognizing team formation in american football

KAUST Repository

Atmosukarto, Indriyati

2014-01-01

Most existing software packages for sports video analysis require manual annotation of important events in the video. Despite being the most popular sport in the United States, most American football game analysis is still done manually. Line of scrimmage and offensive team formation recognition are two statistics that must be tagged by American Football coaches when watching and evaluating past play video clips, a process which takesmanyman hours per week. These two statistics are the building blocks for more high-level analysis such as play strategy inference and automatic statistic generation. In this chapter, we propose a novel framework where given an American football play clip, we automatically identify the video frame in which the offensive team lines in formation (formation frame), the line of scrimmage for that play, and the type of player formation the offensive team takes on. The proposed framework achieves 95% accuracy in detecting the formation frame, 98% accuracy in detecting the line of scrimmage, and up to 67%accuracy in classifying the offensive team’s formation. To validate our framework, we compiled a large dataset comprising more than 800 play-clips of standard and high definition resolution from real-world football games. This dataset will be made publicly available for future comparison.

STAR FORMATION IN DISK GALAXIES. II. THE EFFECT OF STAR FORMATION AND PHOTOELECTRIC HEATING ON THE FORMATION AND EVOLUTION OF GIANT MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Tasker, Elizabeth J.

2011-01-01

We investigate the effect of star formation and diffuse photoelectric heating on the properties of giant molecular clouds (GMCs) formed in high-resolution (∼ H,c >100 cm -3 are identified as GMCs. Between 1000 and 1500 clouds are created in the simulations with masses M>10 5 M sun and 180-240 with masses M>10 6 M sun in agreement with estimates of the Milky Way's population. We find that the effect of photoelectric heating is to suppress the fragmentation of the interstellar medium, resulting in a filamentary structure in the warm gas surrounding clouds. This environment suppresses the formation of a retrograde rotating cloud population, with 88% of the clouds rotating prograde with respect to the galaxy after 300 Myr. The diffuse heating also reduces the initial star formation rate (SFR), slowing the conversation of gas into stars. We therefore conclude that the interstellar environment plays an important role in the GMC evolution. Our clouds live between 0 and 20 Myr with a high infant mortality (t' < 3 Myr) due to cloud mergers and star formation. Other properties, including distributions of mass, size, and surface density, agree well with observations. Collisions between our clouds are common, occurring at a rate of ∼ 1/4 of the orbital period. It is not clear whether such collisions trigger or suppress star formation at our current resolution. Our SFR is a factor of 10 higher than observations in local galaxies. This is likely due to the absence of localized feedback in our models.

Aggregate formation in 3D turbulent-like flows

NARCIS (Netherlands)

Dominguez, A.; Aartrijk, van M.; Castello, Del L.; Clercx, H.J.H.; Geurts, B.; Clercx, H

2006-01-01

Aggregate formation is an important process in industrial and environ mental turbulent flows. Two examples in the environmental area, where turbulent aggregate formation takes place, are raindrop formation in clouds and Marine Snow (aggregate) formation in the upper layer in the oceans. The

Chlorination and chloramines formation

International Nuclear Information System (INIS)

Yee, Lim Fang; Mohd Pauzi Abdullah; Sadia Ata; Abbas Abdullah; Basar IShak; Khairul Nidzham

2008-01-01

Chlorination is the most important method of disinfection in Malaysia which aims at ensuring an acceptable and safe drinking water quality. The dosing of chlorine to surface water containing ammonia and nitrogen compounds may form chloramines in the treated water. During this reaction, inorganic and organic chloramines are formed. The recommended maximum acceptable concentration (MAC) for chloramines in drinking water is 3000 μg/L. The production of monochloramine, dichloramine and trichloramine is highly dependent upon pH, contact time and the chlorine to ammonia molar ratio. The purpose of this study is to examine the formation of chloramines that occur upon the chlorination during the treatment process. Chloramines were determined using the N,N-diethyl-p-phenylenediamine (DPD) colorimetric method. The influences of ammonia, pH and chlorine dosage on the chloramines formation were also studied. This paper presents a modeling approach based on regression analysis which is designed to estimate the formation of chloramines. The correlation between the concentration of chloramines and the ammonia, pH and chlorine dosage was examined. In all cases, the quantity of chloramines formed depended linearly upon the amount of chlorine dosage. On the basis of this study it reveals that the concentration of chloramines is a function of chlorine dosage and the ammonia concentration to the chlorination process. PH seems to not significantly affect the formation of chloramines. (author)

Flowchart-format emergency operating procedures-strengths and weaknesses

International Nuclear Information System (INIS)

Barnes, V.E.; Bongarra, J.P. Jr.

1989-01-01

An increasing number of nuclear power plant licensees are converting their text-format emergency operating procedures (EOPs) to flowcharts. Findings of a recent study of the flowchart-format EOPs indicate that the flowchart format appears to solve several significant usability problems associated with text-format EOPs, but also introduces other types of usability concerns. This paper discusses some of the strengths and weaknesses of the flowchart format for presenting EOPs

Formation Number Of Laminar Vortex Rings. Numerical Simulations

International Nuclear Information System (INIS)

Rosenfeld, M.; Rambod, E.; Gharib, M.

1998-01-01

The formation time scale of axisymmetric vortex rings is studied numerically for relatively long discharge times. Experimental findings on the existence and universality of a formation time scale, referred to as the formation number, are confirmed. The formation number is indicative of the time a vortex ring acquires its maximal circulation. For vortex rings generated by impulsive motion of a piston, the formation number was found experimentally to be approximately 4. Numerical extension of the experimental study to thick shear layers indicates that the scaled circulation of the pinched-off vortex is relatively insensitive of the details of the formation process, such as the velocity program, velocity profile or vortex generator geometry. In contrast, the formation number does depend on the velocity profile

Portable File Format (PFF) specifications

Energy Technology Data Exchange (ETDEWEB)

Dolan, Daniel H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-02-01

Created at Sandia National Laboratories, the Portable File Format (PFF) allows binary data transfer across computer platforms. Although this capability is supported by many other formats, PFF files are still in use at Sandia, particularly in pulsed power research. This report provides detailed PFF specifications for accessing data without relying on legacy code.

Satellite Formation Control Using Atmospheric Drag

National Research Council Canada - National Science Library

Hajovsky, Blake B

2007-01-01

This study investigates the use of a linear quadratic terminal controller to reconfigure satellite formations using atmospheric drag actuated control while minimizing the loss of energy of the formation...

Formation and elution of toxic compounds from sterilized medical products: toxic compound formation from irradiated products

International Nuclear Information System (INIS)

Shintani, Hideharu

1996-01-01

No formation of MDA was observed in chain-extended thermoplastic polyurethane (PU) when sterilized by autoclave or γ-ray irradiation. No formation of MDA was observed in nonchain-extended thermoplastic PU when sterilized by γ-ray irradiation. Less than 1 ppm MDA was produced in nonchain-extended thermoplastic PU sterilized by autoclave sterilization. Autoclave sterilization did not produce MDA in thermosetting PU potting material. MDA formation in potting material was promoted by γ-irradiation and increased with increasing irradiation at a quadratic equation of regression. MDA formation at 100 kGy irradiation is a few ppm and < 1 ppm at 25kGy irradiation, therefore the potential risk to human recipients was not significant. The elution of compounds other than MDA from potting material was more problematic. Solvent extracts from potting material presented mutagenicity in the absence of metabolic activity. MDA presented mutagenicity in the presence of metabolic activity, therefore MDA was not the mutagenic trigger. The chemical and biological characteristics of the specific mutagens required to identify in a further study. Negative promotion of MDA formation and a less presence of mutagen in autoclave sterilized potting material indicated that autoclave sterilization was preferable. (Author)

Formation and behaviour of organic iodine

International Nuclear Information System (INIS)

Zilliacus, R.; Koukkar, P.; Karjunen, T.; Sjoevall, H.

2002-01-01

The report presents experimental studies on the formation of organic iodine in severe reactor accidents. The analyses were performed to evaluate the amount of alkaline chemical needed for effective pH control of containment water during the accidents. The formation of organic iodine in solutions used in the filtered venting system and the absorption of iodine compounds in the solutions were studied. Experiments for the formation of organic iodine on painted surfaces were also performed. (au)

Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

Energy Technology Data Exchange (ETDEWEB)

Crespillo, M.L., E-mail: mcrespil@utk.edu [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Department of Materials Science & Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Agulló-López, F., E-mail: fal@uam.es [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Zucchiatti, A. [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain)

2017-03-01

Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO{sub 3} crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

Morrowan stratigraphy, depositional systems, and hydrocarbon accumulation, Sorrento field, Cheyenne County, Colorado

Energy Technology Data Exchange (ETDEWEB)

Orchard, D.M.; Kidwell, M.R.

1983-08-01

The Sorrento field, located on the western flank of the present-day Las Animas arch in western Cheyenne County, Colorado, has approximately 29 million bbl of oil and 12 bcf of gas in place in sandstones of the Lower Pennsylvanian Morrow units. The sandstones were deposited in a fluvially dominated deltaic system, and the trap for the hydrocarbon accumulation is formed by pinch-out of this deltaic system onto regional dip. The primary reservoirs are point-bar deposits. At the Sorrento field, the basal Keyes limestone member of the Morrow formation rests unconformably on the Mississippian St. Louis Formation. Above the Keyes limestone, the Morrow shale is 180 to 214 ft (55 to 65 m) thick, and locally contains reservoir sands. Gas/oil and oil/water contacts are not uniform through the field owing to discontinuities between separate point bars. One such discontinuity is formed by an apparent mud plug of an abandoned channel separating two point bars on the southeastern end of the field. In a well 7000 ft (2100 m) from the edge of the meander belt, the regressive sequence is represented by a shoreline siltstone unit 8 ft (2 m) thick with flaser bedding, graded bedding, load structures, and rare wave-ripple cross-bedding overlain by 3 ft (1 m) of flood-plain mudstone and coal with no indication of proximity to a nearby sand system.

Application of magnetic techniques to lateral hydrocarbon migration - Lower Tertiary reservoir systems, UK North Sea

Science.gov (United States)

Badejo, S. A.; Muxworthy, A. R.; Fraser, A.

2017-12-01

Pyrolysis experiments show that magnetic minerals can be produced inorganically during oil formation in the `oil-kitchen'. Here we try to identify a magnetic proxy that can be used to trace hydrocarbon migration pathways by determining the morphology, abundance, mineralogy and size of the magnetic minerals present in reservoirs. We address this by examining the Tay formation in the Western Central Graben in the North Sea. The Tertiary sandstones are undeformed and laterally continuous in the form of an east-west trending channel, facilitating long distance updip migration of oil and gas to the west. We have collected 179 samples from 20 oil-stained wells and 15 samples from three dry wells from the British Geological Survey Core Repository. Samples were selected based on geological observations (water-wet sandstone, oil-stained sandstone, siltstones and shale). The magnetic properties of the samples were determined using room-temperature measurements on a Vibrating Sample Magnetometer (VSM), low-temperature (0-300K) measurements on a Magnetic Property Measurement System (MPMS) and high-temperature (300-973K) measurements on a Kappabridge susceptibility meter. We identified magnetite, pyrrhotite, pyrite and siderite in the samples. An increasing presence of ferrimagnetic iron sulphides is noticed along the known hydrocarbon migration pathway. Our initial results suggest mineralogy coupled with changes in grain size are possible proxies for hydrocarbon migration.

Hyper-massive cloud, shock and stellar formation efficiency

International Nuclear Information System (INIS)

Louvet, Fabien

2014-01-01

O and B types stars are of paramount importance in the energy budget of galaxies and play a crucial role enriching the interstellar medium. However, their formation, unlike that of solar-type stars, is still subject to debate, if not an enigma. The earliest stages of massive star formation and the formation of their parent cloud are still crucial astrophysical questions that drew a lot of attention in the community, both from the theoretical and observational perspective, during the last decade. It has been proposed that massive stars are born in massive dense cores that form through very dynamic processes, such as converging flows of gas. During my PhD, I conducted a thorough study of the formation of dense cores and massive stars in the W43-MM1 supermassive structure, located at 6 kpc from the sun. At first, I showed a direct correlation between the star formation efficiency and the volume gas density of molecular clouds, in contrast with scenarios suggested by previous studies. Indeed, the spatial distribution and mass function of the massive dense cores currently forming in W43-MM1 suggests that this supermassive filament is undergoing a star formation burst, increasing as one approaches its center. I compared these observational results with the most recent numerical and analytical models of star formation. This comparison not only provides new constraints on the formation of supermassive filaments, but also suggests that understanding star formation in high density, extreme ridges requires a detailed portrait of the structure of these exceptional objects. Second, having shown that the formation of massive stars depends strongly on the properties of the ridges where they form, I studied the formation processes of these filaments, thanks of the characterization of their global dynamics. Specifically, I used a tracer of shocks (SiO molecule) to disentangle the feedback of local star formation processes (bipolar jets and outflows) from shocks tracing the pristine

Autonomous formation flight of helicopters: Model predictive control approach

Science.gov (United States)

Chung, Hoam

Formation flight is the primary movement technique for teams of helicopters. However, the potential for accidents is greatly increased when helicopter teams are required to fly in tight formations and under harsh conditions. This dissertation proposes that the automation of helicopter formations is a realistic solution capable of alleviating risks. Helicopter formation flight operations in battlefield situations are highly dynamic and dangerous, and, therefore, we maintain that both a high-level formation management system and a distributed coordinated control algorithm should be implemented to help ensure safe formations. The starting point for safe autonomous formation flights is to design a distributed control law attenuating external disturbances coming into a formation, so that each vehicle can safely maintain sufficient clearance between it and all other vehicles. While conventional methods are limited to homogeneous formations, our decentralized model predictive control (MPC) approach allows for heterogeneity in a formation. In order to avoid the conservative nature inherent in distributed MPC algorithms, we begin by designing a stable MPC for individual vehicles, and then introducing carefully designed inter-agent coupling terms in a performance index. Thus the proposed algorithm works in a decentralized manner, and can be applied to the problem of helicopter formations comprised of heterogenous vehicles. Individual vehicles in a team may be confronted by various emerging situations that will require the capability for in-flight reconfiguration. We propose the concept of a formation manager to manage separation, join, and synchronization of flight course changes. The formation manager accepts an operator's commands, information from neighboring vehicles, and its own vehicle states. Inside the formation manager, there are multiple modes and complex mode switchings represented as a finite state machine (FSM). Based on the current mode and collected

Heating tar sands formations to visbreaking temperatures

Science.gov (United States)

Karanikas, John Michael [Houston, TX; Colmenares, Tulio Rafael [Houston, TX; Zhang, Etuan [Houston, TX; Marino, Marian [Houston, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX; Ryan, Robert Charles [Houston, TX; Beer, Gary Lee [Houston, TX; Dombrowski, Robert James [Houston, TX; Jaiswal, Namit [Houston, TX

2009-12-22

Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

Interoperability format translation and transformation between IFC architectural design file and simulation file formats

Science.gov (United States)

Chao, Tian-Jy; Kim, Younghun

2015-01-06

Automatically translating a building architecture file format (Industry Foundation Class) to a simulation file, in one aspect, may extract data and metadata used by a target simulation tool from a building architecture file. Interoperability data objects may be created and the extracted data is stored in the interoperability data objects. A model translation procedure may be prepared to identify a mapping from a Model View Definition to a translation and transformation function. The extracted data may be transformed using the data stored in the interoperability data objects, an input Model View Definition template, and the translation and transformation function to convert the extracted data to correct geometric values needed for a target simulation file format used by the target simulation tool. The simulation file in the target simulation file format may be generated.

Star formation in the multiverse

International Nuclear Information System (INIS)

Bousso, Raphael; Leichenauer, Stefan

2009-01-01

We develop a simple semianalytic model of the star formation rate as a function of time. We estimate the star formation rate for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

Mantle dynamics following supercontinent formation

Science.gov (United States)

Heron, Philip J.

This thesis presents mantle convection numerical simulations of supercontinent formation. Approximately 300 million years ago, through the large-scale subduction of oceanic sea floor, continental material amalgamated to form the supercontinent Pangea. For 100 million years after its formation, Pangea remained relatively stationary, and subduction of oceanic material featured on its margins. The present-day location of the continents is due to the rifting apart of Pangea, with supercontinent dispersal being characterized by increased volcanic activity linked to the generation of deep mantle plumes. The work presented here investigates the thermal evolution of mantle dynamics (e.g., mantle temperatures and sub-continental plumes) following the formation of a supercontinent. Specifically, continental insulation and continental margin subduction are analyzed. Continental material, as compared to oceanic material, inhibits heat flow from the mantle. Previous numerical simulations have shown that the formation of a stationary supercontinent would elevate sub-continental mantle temperatures due to the effect of continental insulation, leading to the break-up of the continent. By modelling a vigorously convecting mantle that features thermally and mechanically distinct continental and oceanic plates, this study shows the effect of continental insulation on the mantle to be minimal. However, the formation of a supercontinent results in sub-continental plume formation due to the re-positioning of subduction zones to the margins of the continent. Accordingly, it is demonstrated that continental insulation is not a significant factor in producing sub-supercontinent plumes but that subduction patterns control the location and timing of upwelling formation. A theme throughout the thesis is an inquiry into why geodynamic studies would produce different results. Mantle viscosity, Rayleigh number, continental size, continental insulation, and oceanic plate boundary evolution are

The three phases of galaxy formation

Science.gov (United States)

Clauwens, Bart; Schaye, Joop; Franx, Marijn; Bower, Richard G.

2018-05-01

We investigate the origin of the Hubble sequence by analysing the evolution of the kinematic morphologies of central galaxies in the EAGLE cosmological simulation. By separating each galaxy into disc and spheroidal stellar components and tracing their evolution along the merger tree, we find that the morphology of galaxies follows a common evolutionary trend. We distinguish three phases of galaxy formation. These phases are determined primarily by mass, rather than redshift. For M* ≲ 109.5M⊙ galaxies grow in a disorganised way, resulting in a morphology that is dominated by random stellar motions. This phase is dominated by in-situ star formation, partly triggered by mergers. In the mass range 109.5M⊙ ≲ M* ≲ 1010.5M⊙ galaxies evolve towards a disc-dominated morphology, driven by in-situ star formation. The central spheroid (i.e. the bulge) at z = 0 consists mostly of stars that formed in-situ, yet the formation of the bulge is to a large degree associated with mergers. Finally, at M* ≳ 1010.5M⊙ growth through in-situ star formation slows down considerably and galaxies transform towards a more spheroidal morphology. This transformation is driven more by the buildup of spheroids than by the destruction of discs. Spheroid formation in these galaxies happens mostly by accretion at large radii of stars formed ex-situ (i.e. the halo rather than the bulge).

Hard sludge formation in modern steam generators of nuclear power plants. Formation, risks and mitigation

International Nuclear Information System (INIS)

Strohmer, F.

2014-01-01

In recent years modern steam generators with triangular pitch tube bundle geometry have experienced damage caused by hard sludge formation on top of the tube sheet and denting. The effect can lead to a limitation of the modern steam generators’ lifetime. The current publication shows reasons for the generation of hard sludge formation. Moreover, it describes the risk arising from hard sludge formation for the concerned steam generators and the mitigation of the problem. The main factors contributing to the formation of hard sludge are: the amount of corrosion product ingress into the steam generators, hard sludge formation favouring impurities and, skipped maintenance applications during outages. The main damaging mechanism of denting that can arise under certain secondary side conditions from hard sludge is explained. For steam generator tube denting, aggressive, oxidizing conditions have to be established in crevices beneath the hard sludge piles. Severely dented tubes are sensitive toward outer diameter stress corrosion cracking (ODSCC). The denting and ODSCC mechanism is explained. In addition, a proactive long-term maintenance strategy to avoid the formation of hard sludge piles will be shown. The strategy is based on a reduction of the corrosion product ingress into the steam generator's secondary side, and on the regular removal of deposits from the tube sheet and from the entire upper bundle area by latest mechanical cleaning methods. For hard deposits - formed either by silicates or long term hardened corrosion products, which, in the past, could not be removed by chemical or mechanical means - a new, simple, mechanical cleaning method is presented. This method can be used during the normal time frame of an outage and allows the restart of the unit with clean steam generator tube sheets. This mitigates the tendency to form hard sludge and denting in the long term. (author)

Muonium/muonic hydrogen formation in atomic hydrogen

Indian Academy of Sciences (India)

The muonium/muonic hydrogen atom formation in ± –H collisions is investigated, using a two-state approximation in a time dependent formalism. It is found that muonium cross-section results are similar to the cross-section results obtained for positronium formation in + –H collision. Muonic hydrogen atom formation ...

Formative assessment: a student perspective.

Science.gov (United States)

Hill, D A; Guinea, A I; McCarthy, W H

1994-09-01

An educator's view would be that formative assessment has an important role in the learning process. This study was carried out to obtain a student perspective of the place of formative assessment in the curriculum. Final-year medical students at Royal Prince Alfred Hospital took part in four teaching sessions, each structured to integrate teaching with assessment. Three assessment methods were used; the group objective structured clinical examination (G-OSCE), structured short answer (SSA) questions and a pre/post-test multiple choice questionnaire (MCQ). Teaching sessions were conducted on the subject areas of traumatology, the 'acute abdomen', arterial disorders and cancer. Fifty-five students, representing 83% of those who took part in the programme, responded to a questionnaire where they were asked to rate (on a 5-point Likert scale) their response to general questions about formative assessment and 13 specific questions concerning the comparative value of the three assessment modalities. Eighty-nine per cent of respondents felt that formative assessment should be incorporated into the teaching process. The SSA assessment was regarded as the preferred modality to reinforce previous teaching and test problem-solving skills. The MCQ was the least favoured assessment method. The effect size variable between the total scores for the SSA and MCQ was 0.64. The variable between G-OSCE and SSA/MCQ was 0.26 and 0.33 respectively. Formative assessment is a potentially powerful method to direct learning behaviour. Students should have input into the methods used.

Secretory processes involved in the formation of milk

International Nuclear Information System (INIS)

Knutsson, P.G.

1976-01-01

Current knowledge on milk formation is reviewed. Emphasis is given to sites of formation of protein, fat and lactose, and transfer of these compounds into the alveolar lumen. Further, the formation of the water phase of milk is thoroughly discussed, and evidence presented that milk formation includes both secretory and re-absorptive processes as well as diffusion. A short presentation of colostrum formation is included. Neither biochemical processes involved in synthesis of organic compounds nor mammary gland endocrinology are discussed. (author)

Increased formate overflow is a hallmark of oxidative cancer.

Science.gov (United States)

Meiser, Johannes; Schuster, Anne; Pietzke, Matthias; Vande Voorde, Johan; Athineos, Dimitris; Oizel, Kristell; Burgos-Barragan, Guillermo; Wit, Niek; Dhayade, Sandeep; Morton, Jennifer P; Dornier, Emmanuel; Sumpton, David; Mackay, Gillian M; Blyth, Karen; Patel, Ketan J; Niclou, Simone P; Vazquez, Alexei

2018-04-10

Formate overflow coupled to mitochondrial oxidative metabolism\\ has been observed in cancer cell lines, but whether that takes place in the tumor microenvironment is not known. Here we report the observation of serine catabolism to formate in normal murine tissues, with a relative rate correlating with serine levels and the tissue oxidative state. Yet, serine catabolism to formate is increased in the transformed tissue of in vivo models of intestinal adenomas and mammary carcinomas. The increased serine catabolism to formate is associated with increased serum formate levels. Finally, we show that inhibition of formate production by genetic interference reduces cancer cell invasion and this phenotype can be rescued by exogenous formate. We conclude that increased formate overflow is a hallmark of oxidative cancers and that high formate levels promote invasion via a yet unknown mechanism.

String Formatting Considered Harmful for Novice Programmers

Science.gov (United States)

Hughes, Michael C.; Jadud, Matthew C.; Rodrigo, Ma. Mercedes T.

2010-01-01

In Java, "System.out.printf" and "String.format" consume a specialised kind of string commonly known as a format string. In our study of first-year students at the Ateneo de Manila University, we discovered that format strings present a substantial challenge for novice programmers. Focusing on their first laboratory we found…

Planet Formation

Science.gov (United States)

Podolak, Morris

2018-04-01

Modern observational techniques are still not powerful enough to directly view planet formation, and so it is necessary to rely on theory. However, observations do give two important clues to the formation process. The first is that the most primitive form of material in interstellar space exists as a dilute gas. Some of this gas is unstable against gravitational collapse, and begins to contract. Because the angular momentum of the gas is not zero, it contracts along the spin axis, but remains extended in the plane perpendicular to that axis, so that a disk is formed. Viscous processes in the disk carry most of the mass into the center where a star eventually forms. In the process, almost as a by-product, a planetary system is formed as well. The second clue is the time required. Young stars are indeed observed to have gas disks, composed mostly of hydrogen and helium, surrounding them, and observations tell us that these disks dissipate after about 5 to 10 million years. If planets like Jupiter and Saturn, which are very rich in hydrogen and helium, are to form in such a disk, they must accrete their gas within 5 million years of the time of the formation of the disk. Any formation scenario one proposes must produce Jupiter in that time, although the terrestrial planets, which don't contain significant amounts of hydrogen and helium, could have taken longer to build. Modern estimates for the formation time of the Earth are of the order of 100 million years. To date there are two main candidate theories for producing Jupiter-like planets. The core accretion (CA) scenario supposes that any solid materials in the disk slowly coagulate into protoplanetary cores with progressively larger masses. If the core remains small enough it won't have a strong enough gravitational force to attract gas from the surrounding disk, and the result will be a terrestrial planet. If the core grows large enough (of the order of ten Earth masses), and the disk has not yet dissipated, then

Exploring the value of usability feedback formats

DEFF Research Database (Denmark)

Nørgaard, Mie; Hornbæk, Kasper Anders Søren

2009-01-01

The format used to present feedback from usability evaluations to developers affects whether problems are understood, accepted, and fixed. Yet, little research has investigated which formats are the most effective. We describe an explorative study where three developers assess 40 usability findings...... presented using five feedback formats. Our usability findings comprise 35 problems and 5 positive comments. Data suggest that feedback serves multiple purposes. Initially, feedback must convince developers about the relevance of a problem and convey an understanding of this. Feedback must next be easy...... working with the feedback to address the usability problems, there were no significant differences among the developers' ratings of the value of the different formats. This suggests that all of the formats may serve equally well as reminders in later stages of working with usability problems...

The role of the family in personality formation

Directory of Open Access Journals (Sweden)

Pylkov E.A.

2018-04-01

Full Text Available the article reveals such actual components of modern society as family, personality formation in the family, formation of the self-concept, life-purpose orientations of modern youth. One of the key moments in personality formation is movement, action. Formation involves personality development, both physically and spiritually from the very beginning of a person's life.

Academic Formation and Formative Research Integration Management for the Culmination of Studies Process in Higher Education

Directory of Open Access Journals (Sweden)

Lorna Cruz Rizo

2016-12-01

Full Text Available Given the up- dated international difficulties in the completion of studies process, theoretical and practical studies developed in this field are surprisingly scarce. Particularly, there has been a limited quantity of students that support their diploma thesis after completing their credits at the School of Languages and Linguistics at the University of Guayaquil. Consequently, this paper faces the problem of the insufficiencies in the culmination of studies process in relation to the management of the academic and scientific formation. Thus, the objective is: to improve the completion of studies or degree- obtaining processes in university education, through the implementation of a praxiological proposal of academic formation and formative research integration. Accordingly, the author´s experiences systematization is the methodology mainly used. The essential logic for the management of the academic formation and formative research integration was revealed as the main proposal, therefore this is the solution to the problem diagnosed. This is based on a curricular structure, in which each of the subjects was interrelated to each of the essential stages of the scientific research. As main results obtained, the students were able to solve real-life problems diagnosed at educative institutions, also they drew up the draft of their theses.

Glauconitic deposits at Julegård on the south coast of Bornholm, Denmark dated to the Cambrian

DEFF Research Database (Denmark)

Clemmensen, Lars B.; Bromley, Richard Granville; Holm, Paul Martin

2011-01-01

Bioturbated, glauconitic siltstones and sandstones are overlain by presumed Upper Triassic deposits at coastal exposures at Julegård on the south coast of Bornholm. These glauconitic deposits have not previously been dated. A 40Ar-39Ar dating of the glaucony gives an age of 493 ± 2 Ma suggesting ...... of Rusophycus Hall, 1852, probably trilobite trace fossils, are also represented....

Environmental Assessment Addressing Gate Complex Construction at Scott Air Force Base, Illinois

Science.gov (United States)

2014-04-01

of low permeability, Pennsylvanian-age shale with thin, discontinuous beds of sandstone and limestone (SAFB 2011c). EA for Gate Complex...deposits is the Pennsylvanian-age layers of shale, siltstone, sandstone , limestone, claystone, and coal, lying approximately 85 feet below ground surface...The Pennsylvanian strata are approximately 265 feet thick. Water-yielding Chesterian Series sandstones lie beneath the Pennsylvanian strata. The

Cost Effective, Ultra Sensitive Groundwater Monitoring for Site Remediation and Management

Science.gov (United States)

2015-05-01

evaporites, sandstone, gravel, conglomerate, and andesitic basalt . Closed basin; playa, alluvial fan, fluvial 600 to 10,000+ Unconfined, leaky...confined Lower unit Breccia, conglomerate, sandstone, siltstone, and local basaltic to rhyolitic flows and pyroclastic rocks. Alluvial fan, fluvial...with large volumes of groundwater. Three of the cartridges additionally protected by glass fiber filters (Acrodisc AP-4523; Pall GmbH, Dreieich, GE

Planetesimal formation starts at the snow line

Science.gov (United States)

Drążkowska, J.; Alibert, Y.

2017-12-01

Context. The formation stage of planetesimals represents a major gap in our understanding of the planet formation process. Late-stage planet accretion models typically make arbitrary assumptions about planetesimal and pebble distribution, while dust evolution models predict that planetesimal formation is only possible at some orbital distances. Aims: We wish to test the importance of the water snow line in triggering the formation of the first planetesimals during the gas-rich phase of a protoplanetary disk, when cores of giant planets have to form. Methods: We connected prescriptions for gas disk evolution, dust growth and fragmentation, water ice evaporation and recondensation, the transport of both solids and water vapor, and planetesimal formation via streaming instability into a single one-dimensional model for protoplanetary disk evolution. Results: We find that processes taking place around the snow line facilitate planetesimal formation in two ways. First, because the sticking properties between wet and dry aggregates change, a "traffic jam" inside of the snow line slows the fall of solids onto the star. Second, ice evaporation and outward diffusion of water followed by its recondensation increases the abundance of icy pebbles that trigger planetesimal formation via streaming instability just outside of the snow line. Conclusions: Planetesimal formation is hindered by growth barriers and radial drift and thus requires particular conditions to take place. The snow line is a favorable location where planetesimal formation is possible for a wide range of conditions, but not in every protoplanetary disk model, however. This process is particularly promoted in large cool disks with low intrinsic turbulence and an increased initial dust-to-gas ratio. The movie attached to Fig. 3 is only available at http://www.aanda.org

Composition of the Rex Chert and associated rocks of the Permian Phosphoria Formation: Soda Springs area, SE Idaho

Science.gov (United States)

Hein, James R.; McIntyre, Brandie; Perkins, Robert B.; Piper, David Z.; Evans, James

2002-01-01

This study, one in a series, reports bulk chemical and mineralogical compositions, as well as petrographic and outcrop descriptions of rocks collected from three measured outcrop sections of the Rex Chert member of the Phosphoria Formation in SE Idaho. The three measured sections were chosen from ten outcrops of Rex Chert that were described in the field. The Rex Chert overlies the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, the source of phosphate ore in the region. Rex Chert removed as overburden comprises part of the material disposed in waste-rock piles during phosphate mining. It has been proposed that the chert be used to cap and isolate waste piles, thereby inhibiting the leaching of potentially toxic elements into the environment. It is also used to surface roads in the mining district. The rock samples studied here constitute a set of individual chert beds that are representative of each stratigraphic section sampled. The informally named cherty shale member that overlies the Rex Chert in measured section 1 was also described and sampled. The upper Meade Peak and the transition zone to the Rex Chert were described and sampled in section 7. The cherts are predominantly spicularite composed of granular and mosaic quartz, and sponge spicules, with various but minor amounts of other fossils and detrital grains. The cherty shale member and transition rocks between the Meade Peak and Rex Chert are siliceous siltstones and argillaceous cherts with ghosts of sponge spicules and somewhat more detrital grains than the chert. The overwhelmingly dominant mineral is quartz, although carbonate beds are rare in each section and are composed predominantly of calcite and dolomite in addition to quartz. Feldspar, mica, clay minerals, calcite, dolomite, and carbonate fluorapatite are minor to trace minerals in the chert. The mean concentrations of oxides and elements in the Rex Chert and the cherty shale member are dominated by SiO2, which averages 94

Terrestrial planet formation.

Science.gov (United States)

Righter, K; O'Brien, D P

2011-11-29

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Star formation in active galaxies and quasars

International Nuclear Information System (INIS)

Heckman, T.M.

1987-01-01

I review the observational evidence for a causal or statistical link between star formation and active galactic nuclei. The chief difficulty is in quantitatively ascertaining the star formation rate in active galaxies: most of the readily observable manifestations of star formation superficially resemble those of an active nucleus. Careful multi-wavelength spatially-resolved observations demonstrate that many Seyfert galaxies are undergoing star formation. Our survey of CO emission from Seyferts (interpreted in conjunction IRAS data) suggests that type 2 Seyferts have unusually high rates of star formation, but type 1 Seyferts do not. Recent work also suggests that many powerful radio galaxies may be actively forming stars: radio galaxies with strong emission-lines often have blue colors and strong far-infrared emission. Determining the star formation rate in the host galaxies of quasars is especially difficult. Multi-color imaging and long-slit spectroscopy suggests that many of the host galaxies of radio-loud quasars are blue and a cold interstellar medium has been detected in some quasar hosts

Networks for Autonomous Formation Flying Satellite Systems

Science.gov (United States)

Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

2001-01-01

The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

Radiation pressure in super star cluster formation

Science.gov (United States)

Tsang, Benny T.-H.; Milosavljević, Miloš

2018-05-01

The physics of star formation at its extreme, in the nuclei of the densest and the most massive star clusters in the universe—potential massive black hole nurseries—has for decades eluded scrutiny. Spectroscopy of these systems has been scarce, whereas theoretical arguments suggest that radiation pressure on dust grains somehow inhibits star formation. Here, we harness an accelerated Monte Carlo radiation transport scheme to report a radiation hydrodynamical simulation of super star cluster formation in turbulent clouds. We find that radiation pressure reduces the global star formation efficiency by 30-35%, and the star formation rate by 15-50%, both relative to a radiation-free control run. Overall, radiation pressure does not terminate the gas supply for star formation and the final stellar mass of the most massive cluster is ˜1.3 × 106 M⊙. The limited impact as compared to in idealized theoretical models is attributed to a radiation-matter anti-correlation in the supersonically turbulent, gravitationally collapsing medium. In isolated regions outside massive clusters, where the gas distribution is less disturbed, radiation pressure is more effective in limiting star formation. The resulting stellar density at the cluster core is ≥108 M⊙ pc-3, with stellar velocity dispersion ≳ 70 km s-1. We conclude that the super star cluster nucleus is propitious to the formation of very massive stars via dynamical core collapse and stellar merging. We speculate that the very massive star may avoid the claimed catastrophic mass loss by continuing to accrete dense gas condensing from a gravitationally-confined ionized phase.

JOYFOR: A program for transformation of NJOY results in MATXS-format to the MITRA input format

International Nuclear Information System (INIS)

Krieg, B.; Broeders, I.

1987-02-01

The program JOYFOR is the connection between the output of the group constant calculation code NJOY in MATXS-format and the testing and formatting program MITRA. Resonance selfshielding factors as well as transfermatrices for elastic and inelastic scattering and for (n,2n)- and (n,3n)-processes, normalized corresponding to the conventions of MITRA, are calculated by JOYFOR from the NJOY results and are written in MIGROS-format on an external file and on the standard output unit. Also the group cross-sections for infinite dilution, the 1/v-values and the fission spectrum are written out in the same format as in MIGROS. KERMA-factors are handled by JOYFOR in the same way as group cross-sections. The output data of JOYFOR may be tested by MITRA and transformed into input for the GRUBA management program GRUMA. The present version of JOYFOR handles group constants for neutron reactions only. Extension of the program to photon reactions is being planned. (orig.) [de

Crenarchaeal biofilm formation under extreme conditions.

Directory of Open Access Journals (Sweden)

Andrea Koerdt

Full Text Available BACKGROUND: Biofilm formation has been studied in much detail for a variety of bacterial species, as it plays a major role in the pathogenicity of bacteria. However, only limited information is available for the development of archaeal communities that are frequently found in many natural environments. METHODOLOGY: We have analyzed biofilm formation in three closely related hyperthermophilic crenarchaeotes: Sulfolobus acidocaldarius, S. solfataricus and S. tokodaii. We established a microtitre plate assay adapted to high temperatures to determine how pH and temperature influence biofilm formation in these organisms. Biofilm analysis by confocal laser scanning microscopy demonstrated that the three strains form very different communities ranging from simple carpet-like structures in S. solfataricus to high density tower-like structures in S. acidocaldarius in static systems. Lectin staining indicated that all three strains produced extracellular polysaccharides containing glucose, galactose, mannose and N-acetylglucosamine once biofilm formation was initiated. While flagella mutants had no phenotype in two days old static biofilms of S. solfataricus, a UV-induced pili deletion mutant showed decreased attachment of cells. CONCLUSION: The study gives first insights into formation and development of crenarchaeal biofilms in extreme environments.

Fusomorphogenesis: cell fusion in organ formation.

Science.gov (United States)

Shemer, G; Podbilewicz, B

2000-05-01

Cell fusion is a universal process that occurs during fertilization and in the formation of organs such as muscles, placenta, and bones. Very little is known about the molecular and cellular mechanisms of cell fusion during pattern formation. Here we review the dynamic anatomy of all cell fusions during embryonic and postembryonic development in an organism. Nearly all the cell fates and cell lineages are invariant in the nematode C. elegans and one third of the cells that are born fuse to form 44 syncytia in a reproducible and stereotyped way. To explain the function of cell fusion in organ formation we propose the fusomorphogenetic model as a simple cellular mechanism to efficiently redistribute membranes using a combination of cell fusion and polarized membrane recycling during morphogenesis. Thus, regulated intercellular and intracellular membrane fusion processes may drive elongation of the embryo as well as postembryonic organ formation in C. elegans. Finally, we use the fusomorphogenetic hypothesis to explain the role of cell fusion in the formation of organs like muscles, bones, and placenta in mammals and other species and to speculate on how the intracellular machinery that drive fusomorphogenesis may have evolved.

Transient Exciplex Formation Electron Transfer Mechanism

Directory of Open Access Journals (Sweden)

Michael G. Kuzmin

2011-01-01

Full Text Available Transient exciplex formation mechanism of excited-state electron transfer reactions is analyzed in terms of experimental data on thermodynamics and kinetics of exciplex formation and decay. Experimental profiles of free energy, enthalpy, and entropy for transient exciplex formation and decay are considered for several electron transfer reactions in various solvents. Strong electronic coupling in contact pairs of reactants causes substantial decrease of activation energy relative to that for conventional long-range ET mechanism, especially for endergonic reactions, and provides the possibility for medium reorganization concatenated to gradual charge shift in contrast to conventional preliminary medium and reactants reorganization. Experimental criteria for transient exciplex formation (concatenated mechanism of excited-state electron transfer are considered. Available experimental data show that this mechanism dominates for endergonic ET reactions and provides a natural explanation for a lot of known paradoxes of ET reactions.

Towards the Rosetta Stone of planet formation

Directory of Open Access Journals (Sweden)

Schmidt T.O.B.

2011-02-01

Full Text Available Transiting exoplanets (TEPs observed just ~10 Myrs after formation of their host systems may serve as the Rosetta Stone for planet formation theories. They would give strong constraints on several aspects of planet formation, e.g. time-scales (planet formation would then be possible within 10 Myrs, the radius of the planet could indicate whether planets form by gravitational collapse (being larger when young or accretion growth (being smaller when young. We present a survey, the main goal of which is to find and then characterise TEPs in very young open clusters.

Review of nutrition labeling formats.

Science.gov (United States)

Geiger, C J; Wyse, B W; Parent, C R; Hansen, R G

1991-07-01

This article examines nutrition labeling history as well as the findings of nine research studies of nutrition labeling formats. Nutrition labeling regulations were announced in 1973 and have been periodically amended since then. In response to requests from consumers and health care professionals for revision of the labeling system, the Food and Drug Administration initiated a three-phase plan for reform of nutrition labeling in 1990. President Bush signed the Nutrition Labeling and Education Act in November 1990. Literature analysis revealed that only nine studies with an experimental design have focused on nutrition labeling since 1971. Four were conducted before 1975, which was the year that nutrition labeling was officially implemented, two were conducted in 1980, and three were conducted after 1986. Only two of the nine studies supported the traditional label format mandated by the Code of Federal Regulations, and one study partially supported it. Four of the nine studies that evaluated graphic presentations of nutrition information found that consumer comprehension of nutrition information was improved with a graphic format for nutrition labeling: three studies supported the use of bar graphs and one study supported the use of a pie chart. Full disclosure (ie, complete nutrient and ingredient labeling) was preferred by consumers in two of the three studies that examined this variable. The third study supported three types of information disclosure dependent upon socioeconomic class. In those studies that tested graphics, a bar graph format was significantly preferred and showed better consumer comprehension than the traditional format.

Chain formation of metal atoms

DEFF Research Database (Denmark)

Bahn, Sune Rastad; Jacobsen, Karsten Wedel

2001-01-01

The possibility of formation of single-atomic chains by manipulation of nanocontacts is studied for a selection of metals (Ni, Pd, Pt, Cu, Ag, Au). Molecular dynamics simulations show that the tendency for chain formation is strongest for Au and Pt. Density functional theory calculations indicate...... that the metals which form chains exhibit pronounced many-atom interactions with strong bonding in low coordinated systems....

Influence of fluorosurfactants on hydrate formation rates

Energy Technology Data Exchange (ETDEWEB)

Kim, C.U.; Jeong, K.E.; Chae, H.J.; Jeong, S.Y. [Korea Reasearch Inst. of Chemical Technology, Alternative Chemicals/Fuel Research Center, Yuseong-Gu, Daejon (Korea, Republic of)

2008-07-01

Gas hydrates, or clathrates, are ice-like solids that forms when natural gas is in contact with liquid water or ice under high pressure and low temperature. There is significant interest in studying the storage and transportation of gas in the form of hydrates. However, a critical problem impacting the industrial application of gas hydrates for storage and transportation of natural gas is the slow formation rate of natural gas hydrate. Researchers have previously reported on the promotion effect of some additives on gas hydrate formation and hydrate gas content. Fluorosurfactants are significantly superior to nonfluorinated surfactants in wetting action, as well as stability in harsh environments, both thermal and chemical. This paper discussed an experimental investigation into the effects of fluorosurfactants with different ionic types on the formation of methane hydrate. The surfactants used were FSN-100 of DuPont Zonyl as non-ionic surfactant and FC-143 of DuPont as anionic surfactant. The paper discussed the experimental apparatus for methane hydrate formation. It also discussed hydrate formation kinetics and the series of hydrate formation experiments that were conducted in the presence of fluorosurfactants. Last, the paper explored the results of the study. It was concluded that anionic fluorosurfactant of FC-143 had a better promoting effect on methane hydrate formation compared with nonionic surfactant of FSN-100. 8 refs., 2 tabs., 2 figs.

Distributed formation control for autonomous robots

NARCIS (Netherlands)

Garcia de Marina Peinado, Hector Jesús

2016-01-01

This thesis addresses several theoretical and practical problems related to formation-control of autonomous robots. Formation-control aims to simultaneously accomplish the tasks of forming a desired shape by the robots and controlling their coordinated collective motion. This kind of robot

Computer-based feedback in formative assessment

NARCIS (Netherlands)

van der Kleij, Fabienne

2013-01-01

Formative assessment concerns any assessment that provides feedback that is intended to support learning and can be used by teachers and/or students. Computers could offer a solution to overcoming obstacles encountered in implementing formative assessment. For example, computer-based assessments

Extraction of uranium and copper from sulphate leach liquors of West Central Sinai uraniferrous siltstone of Egypt

International Nuclear Information System (INIS)

Amer, T.E.; Mahdy, M.A.; El-Hazek, N.T.; El Bayoumi, R.M.; Hassanein, S.

2000-01-01

Extraction of uranium and copper from sulphate leach liquors of west central Sinai ore samples were performed using solvent extraction technique. Sulphate leach solutions were processed for the extraction of copper using 3% v/v LIX 973N. Copper extractions higher than 98.1% were obtained. Then, uranium was extracted using a tertiary amine. Two amines have been studied 2% v/v tri-n-octyl amine and 1.5% Alamine 336. Parameters studied included solvents concentration, contact time and solution pH. Stripping of uranium and copper were studied using sodium carbonate and sulphuric acid, respectively. Conditions were established for determining the number of stages required for extraction and stripping of copper and uranium through the construction of the corresponding McCabe-Theile diagrams. The results obtained have been utilized to formulate a proposed flowsheet for the production of uranium and copper from west central Sinai ore samples. (author)

The formation of stars

CERN Document Server

Stahler, Steven W

2008-01-01

This book is a comprehensive treatment of star formation, one of the most active fields of modern astronomy. The reader is guided through the subject in a logically compelling manner. Starting from a general description of stars and interstellar clouds, the authors delineate the earliest phases of stellar evolution. They discuss formation activity not only in the Milky Way, but also in other galaxies, both now and in the remote past. Theory and observation are thoroughly integrated, with the aid of numerous figures and images. In summary, this volume is an invaluable resource, both as a text f

Results of a downhole formation microscanner study in a Juro-Triassic-aged sedimentary deposit (Passaic Formation)

International Nuclear Information System (INIS)

Fischer, J.A.; Fischer, J.J.; Bullwinkel, R.J.

1994-01-01

Studies to determine the structural and geohydrological properties of the Passaic Formation were performed at two sites. Both sites are located in northeastern New Jersey, within the Juro-Triassic-aged Newark Basin. The Passaic Formation rocks are described in the literature as a reddish brown, thin to massively bedded, sedimentary deposit with lithology ranging from claystone through conglomerate. A fractured open-quotes layer cakeclose quotes model has been proposed (and is generally accepted) to describe the prevailing geohydrological conditions. The Formation MicroScanner tool was used in four wells drilled for these projects (two at each site). In addition to this microresistivity tool, a suite of other oil field geophysical tools (Gamma, Induction, Dipmeter, Temperature, and Neutron probes) were also utilized. The data collected with the Formation MicroScanner were correlated with detailed logs and the continuous core retrieved from three of the wells. Pump test data was also obtained at both sites. The geophysical data obtained at both sites allowed the direct identification of fractures and their orientation in relation to bedding. Fracture and bedding aperture size and orientation were measured. The results, as presented in this paper, show a high degree of inhomogeneity at both sites rather than the conventional layer cake model. For appropriate site analyses it was necessary to significantly refine the previously assumed Passaic Formation geohydrological and structural model. 14 refs., 4 figs

Biostratigraphy of the Gurpi Formation in Zagros Basin, Iran

Directory of Open Access Journals (Sweden)

2015-10-01

Full Text Available Introdaction   The Gurpi Formation is developed in the central of the Zagros fold in Khuzestan, Lorestan and Fars provinces of southwestern Iran, defined az theZagros basin ,The Gurpi refers to Gurpi Mountain in the Kuzestan province.type section gurpi,which is N of the Lali oil wells and N-E of Masjed – Soleiman city,comprises 320m argillaceous limestone and gry-to-blueshale marl(James and Wynd,1965Although the boundary the Gurpi Formation and the underlying Ilam Formation is reported to be gradual,the altered facies found at this boundrary could be a sign of a low disconformity or even unconformity.In some place,the Ilam Formation does not exist and tne Gurpi Formation lie abave the Sarvak Formation.The upper boundry of the Gurpi Formation is more noticeable and there are different overlying formations.In Khozstan province,the Gurpi Formation is overlain by purplr shale of pabdeh Formation with signs of unconformity.The Gurpi Formation is not always concurrent. Biostratigraphy and lithological characteries of the Gurpi Formation were studied by James and Wynd (1965, Taheri (1998, KameliAzao (2002, Zarei (2005, Hematinasab (2008, Madavian (2009, Tavalaian (2011. This research study aims at describing the biostratigraphy of Gurpi Formation.In this study five stratigraphic section is investigate for its Planktonc Foraminiforal content.     Method and Matrials   This study involves five stratigraphic sections from the Gurpi Formation that were measured the ticknes and determind of Litostratigrapic limit as well as recognizd of detail litostrstigray the Gurpi Formation.More than 525 thine sections were examined. Some samples from the underlying Pabdeh Formation were also analysed for comparison. then recognizd Genus and species of Planktonic foraminifera and biozones mentioned wells have been introduced. In order to the biozonation of Gurpi Formation, stratigraphic distribution of well- known foraminifora is recognizd and then biozones are

Biostratigraphy of the Gurpi Formation in Zagros Basin, Iran

Directory of Open Access Journals (Sweden)

Abbas Sadeghi

2015-09-01

Full Text Available   Introdaction   The Gurpi Formation is developed in the central of the Zagros fold in Khuzestan, Lorestan and Fars provinces of southwestern Iran, defined az theZagros basin ,The Gurpi refers to Gurpi Mountain in the Kuzestan province.type section gurpi,which is N of the Lali oil wells and N-E of Masjed – Soleiman city,comprises 320m argillaceous limestone and gry-to-blueshale marl(James and Wynd,1965Although the boundary the Gurpi Formation and the underlying Ilam Formation is reported to be gradual,the altered facies found at this boundrary could be a sign of a low disconformity or even unconformity.In some place,the Ilam Formation does not exist and tne Gurpi Formation lie abave the Sarvak Formation.The upper boundry of the Gurpi Formation is more noticeable and there are different overlying formations.In Khozstan province,the Gurpi Formation is overlain by purplr shale of pabdeh Formation with signs of unconformity.The Gurpi Formation is not always concurrent. Biostratigraphy and lithological characteries of the Gurpi Formation were studied by James and Wynd (1965, Taheri (1998, KameliAzao (2002, Zarei (2005, Hematinasab (2008, Madavian (2009, Tavalaian (2011. This research study aims at describing the biostratigraphy of Gurpi Formation.In this study five stratigraphic section is investigate for its Planktonc Foraminiforal content.     Method and Matrials   This study involves five stratigraphic sections from the Gurpi Formation that were measured the ticknes and determind of Litostratigrapic limit as well as recognizd of detail litostrstigray the Gurpi Formation.More than 525 thine sections were examined. Some samples from the underlying Pabdeh Formation were also analysed for comparison. then recognizd Genus and species of Planktonic foraminifera and biozones mentioned wells have been introduced. In order to the biozonation of Gurpi Formation, stratigraphic distribution of well- known foraminifora is recognizd and

Right timing in formative program evaluation.

Science.gov (United States)

Hall, Jori; Freeman, Melissa; Roulston, Kathy

2014-08-01

Since many educational researchers and program developers have limited knowledge of formative evaluation, formative data may be underutilized during the development and implementation of an educational program. The purpose of this article is to explain how participatory, responsive, educative, and qualitative approaches to formative evaluation can facilitate a partnership between evaluators and educational researchers and program managers to generate data useful to inform program implementation and improvement. This partnership is critical, we argue, because it enables an awareness of when to take appropriate action to ensure successful educational programs or "kairos". To illustrate, we use examples from our own evaluation work to highlight how formative evaluation may facilitate opportune moments to (1) define the substance and purpose of a program, (2) develop understanding and awareness of the cultural interpretations of program participants, and (3) show the relevance of stakeholder experiences to program goals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Adolescent Violent Victimization and Precocious Union Formation.

Science.gov (United States)

C Kuhl, Danielle; Warner, David F; Wilczak, Andrew

2012-11-01

This article bridges scholarship in criminology and family sociology by extending arguments about "precocious exits" from adolescence to consider early union formation as a salient outcome of violent victimization for youths. Research indicates that early union formation is associated with several negative outcomes; yet the absence of attention to union formation as a consequence of violent victimization is noteworthy. We address this gap by drawing on life course theory and data from the National Longitudinal Study of Adolescent Health (Add Health) to examine the effect of violent victimization ("street" violence) on the timing of first co-residential union formation-differentiating between marriage and cohabitation-in young adulthood. Estimates from Cox proportional hazard models show that adolescent victims of street violence experience higher rates of first union formation, especially marriage, early in the transition to adulthood; however, this effect declines with age, as such unions become more normative. Importantly, the effect of violent victimization on first union timing is robust to controls for nonviolent delinquency, substance abuse, and violent perpetration. We conclude by discussing directions for future research on the association between violent victimization and coresidential unions with an eye toward the implications of such early union formation for desistance.

Network Configuration Analysis for Formation Flying Satellites

Science.gov (United States)

Knoblock, Eric J.; Wallett, Thomas M.; Konangi, Vijay K.; Bhasin, Kul B.

2001-01-01

The performance of two networks to support autonomous multi-spacecraft formation flying systems is presented. Both systems are comprised of a ten-satellite formation, with one of the satellites designated as the central or 'mother ship.' All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/EP over ATM protocol architecture within the formation, and the second system uses the IEEE 802.11 protocol architecture within the formation. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IP queuing delay, IP queue size and IP processing delay at the mother ship as well as end-to-end delay for both systems. In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

Renewable Formate from C-H Bond Formation with CO2: Using Iron Carbonyl Clusters as Electrocatalysts.

Science.gov (United States)

Loewen, Natalia D; Neelakantan, Taruna V; Berben, Louise A

2017-09-19

As a society, we are heavily dependent on nonrenewable petroleum-derived fuels and chemical feedstocks. Rapid depletion of these resources and the increasingly evident negative effects of excess atmospheric CO 2 drive our efforts to discover ways of converting excess CO 2 into energy dense chemical fuels through selective C-H bond formation and using renewable energy sources to supply electrons. In this way, a carbon-neutral fuel economy might be realized. To develop a molecular or heterogeneous catalyst for C-H bond formation with CO 2 requires a fundamental understanding of how to generate metal hydrides that selectively donate H - to CO 2 , rather than recombining with H + to liberate H 2 . Our work with a unique series of water-soluble and -stable, low-valent iron electrocatalysts offers mechanistic and thermochemical insights into formate production from CO 2 . Of particular interest are the nitride- and carbide-containing clusters: [Fe 4 N(CO) 12 ] - and its derivatives and [Fe 4 C(CO) 12 ] 2- . In both aqueous and mixed solvent conditions, [Fe 4 N(CO) 12 ] - forms a reduced hydride intermediate, [H-Fe 4 N(CO) 12 ] - , through stepwise electron and proton transfers. This hydride selectively reacts with CO 2 and generates formate with >95% efficiency. The mechanism for this transformation is supported by crystallographic, cyclic voltammetry, and spectroelectrochemical (SEC) evidence. Furthermore, installation of a proton shuttle onto [Fe 4 N(CO) 12 ] - facilitates proton transfer to the active site, successfully intercepting the hydride intermediate before it reacts with CO 2 ; only H 2 is observed in this case. In contrast, isoelectronic [Fe 4 C(CO) 12 ] 2- features a concerted proton-electron transfer mechanism to form [H-Fe 4 C(CO) 12 ] 2- , which is selective for H 2 production even in the presence of CO 2 , in both aqueous and mixed solvent systems. Higher nuclearity clusters were also studied, and all are proton reduction electrocatalysts, but none

Formation of the First Stars and Blackholes

Science.gov (United States)

Yoshida, Naoki

2018-05-01

Cosmic reionization is thought to be initiated by the first generation of stars and blackholes. We review recent progress in theoretical studies of early structure formation. Cosmic structure formation is driven by gravitational instability of primeval density fluctuations left over from Big Bang. At early epochs, there are baryonic streaming motions with significant relative velocity with respect to dark matter. The formation of primordial gas clouds is typically delayed by the streaming motions, but then physical conditions for the so-called direct collapse blackhole formation are realized in proto-galactic halos. We present a promising model in which intermediate mass blackholes are formed as early as z = 30.

Simbol-X Formation Flight and Image Reconstruction

Science.gov (United States)

Civitani, M.; Djalal, S.; Le Duigou, J. M.; La Marle, O.; Chipaux, R.

2009-05-01

Simbol-X is the first operational mission relying on two satellites flying in formation. The dynamics of the telescope, due to the formation flight concept, raises a variety of problematic, like image reconstruction, that can be better evaluated via a simulation tools. We present here the first results obtained with Simulos, simulation tool aimed to study the relative spacecrafts navigation and the weight of the different parameters in image reconstruction and telescope performance evaluation. The simulation relies on attitude and formation flight sensors models, formation flight dynamics and control, mirror model and focal plane model, while the image reconstruction is based on the Line of Sight (LOS) concept.

An anti vimentin antibody promotes tube formation

DEFF Research Database (Denmark)

Jørgensen, Mathias Lindh; Møller, Carina Kjeldahl; Rasmussen, Lasse

2017-01-01

antibody technology, promotes tube formation of endothelial cells in a 2D matrigel assay. By binding vimentin, the antibody increases the tube formation by 21% after 5 hours of incubation. Addition of the antibody directly to cultured endothelial cells does not influence endothelial cell migration...... or proliferation. The enhanced tube formation can be seen for up to 10 hours where after the effect decreases. It is shown that the antibody-binding site is located on the coil 2 domain of vimentin. To our knowledge this is the first study that demonstrates an enhanced tube formation by binding vimentin in a 2D...

HOW GALACTIC ENVIRONMENT REGULATES STAR FORMATION

Energy Technology Data Exchange (ETDEWEB)

Meidt, Sharon E. [Max-Planck-Institut für Astronomie/Königstuhl 17 D-69117 Heidelberg (Germany)

2016-02-10

In a new simple model I reconcile two contradictory views on the factors that determine the rate at which molecular clouds form stars—internal structure versus external, environmental influences—providing a unified picture for the regulation of star formation in galaxies. In the presence of external pressure, the pressure gradient set up within a self-gravitating turbulent (isothermal) cloud leads to a non-uniform density distribution. Thus the local environment of a cloud influences its internal structure. In the simple equilibrium model, the fraction of gas at high density in the cloud interior is determined simply by the cloud surface density, which is itself inherited from the pressure in the immediate surroundings. This idea is tested using measurements of the properties of local clouds, which are found to show remarkable agreement with the simple equilibrium model. The model also naturally predicts the star formation relation observed on cloud scales and at the same time provides a mapping between this relation and the closer-to-linear molecular star formation relation measured on larger scales in galaxies. The key is that pressure regulates not only the molecular content of the ISM but also the cloud surface density. I provide a straightforward prescription for the pressure regulation of star formation that can be directly implemented in numerical models. Predictions for the dense gas fraction and star formation efficiency measured on large-scales within galaxies are also presented, establishing the basis for a new picture of star formation regulated by galactic environment.

SCIFIO: an extensible framework to support scientific image formats.

Science.gov (United States)

Hiner, Mark C; Rueden, Curtis T; Eliceiri, Kevin W

2016-12-07

No gold standard exists in the world of scientific image acquisition; a proliferation of instruments each with its own proprietary data format has made out-of-the-box sharing of that data nearly impossible. In the field of light microscopy, the Bio-Formats library was designed to translate such proprietary data formats to a common, open-source schema, enabling sharing and reproduction of scientific results. While Bio-Formats has proved successful for microscopy images, the greater scientific community was lacking a domain-independent framework for format translation. SCIFIO (SCientific Image Format Input and Output) is presented as a freely available, open-source library unifying the mechanisms of reading and writing image data. The core of SCIFIO is its modular definition of formats, the design of which clearly outlines the components of image I/O to encourage extensibility, facilitated by the dynamic discovery of the SciJava plugin framework. SCIFIO is structured to support coexistence of multiple domain-specific open exchange formats, such as Bio-Formats' OME-TIFF, within a unified environment. SCIFIO is a freely available software library developed to standardize the process of reading and writing scientific image formats.

Complex Formation Control of Large-Scale Intelligent Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Ming Lei

2012-01-01

Full Text Available A new formation framework of large-scale intelligent autonomous vehicles is developed, which can realize complex formations while reducing data exchange. Using the proposed hierarchy formation method and the automatic dividing algorithm, vehicles are automatically divided into leaders and followers by exchanging information via wireless network at initial time. Then, leaders form formation geometric shape by global formation information and followers track their own virtual leaders to form line formation by local information. The formation control laws of leaders and followers are designed based on consensus algorithms. Moreover, collision-avoiding problems are considered and solved using artificial potential functions. Finally, a simulation example that consists of 25 vehicles shows the effectiveness of theory.

Extrasolar planets formation, detection and dynamics

CERN Document Server

Dvorak, Rudolf

2008-01-01

This latest, up-to-date resource for research on extrasolar planets covers formation, dynamics, atmospheres and detection. After a look at the formation of giant planets, the book goes on to discuss the formation and dynamics of planets in resonances, planets in double stars, atmospheres and habitable zones, detection via spectra and transits, and the history and prospects of ESPs as well as satellite projects.Edited by a renowned expert in solar system dynamics with chapters written by the leading experts in the method described -- from the US and Europe -- this is an ideal textbook for g

Frasnian-Famennian boundary near Jasper, Alberta, Canada

Energy Technology Data Exchange (ETDEWEB)

Geldsetzer, H.; Goodfellow, W.D.; McLaren, D.; Orchard, M.J.

1985-01-01

The extinction event at the Frasnian-Famennian boundary cannot be associated with a first-order event, whether impact, volcanic or other. However, data from Alberta and western Australia suggest a sudden flooding of cratonic areas by anoxic water as the immediate or second-order cause. In the Rocky Mountains near Jasper, Alberta abrupt sedimentological, geochemical and faunal changes occur between bioturbated dolomitic siltstones below and thinly laminated, very pyritic, argillaceous lime mudstones above. The siltstones which overlie thick subtidal sediments that infilled Middle Frasnian reef topography, were deposited in shallow, well oxygenated water and contain a Frasnian gigas Zone conodont fauna. In contrast, the overlying lime mudstones which pass upward into beds with Famennian triangularis Zone conodonts, represent deposition under strongly anoxic conditions; the contained pyrite has anomalously high delta/sup 34/S values suggesting prolonged bacterial reduction of sulfate to sulfide. The abrupt change to anoxic conditions could have been triggered by an ocean turn-over event as a result of which cratonic areas were flooded with anoxic water. This in turn would have caused a sharp reduction of the biomass and large-scale faunal extinctions.

Uranium prospect inventory on general prospection stage at Sigli sector Aceh

International Nuclear Information System (INIS)

Soetopo, Bambang; Sutriyono, Agus; Sajiyo

2002-01-01

This study based on the considering of the existence of reductive sedimentary rock and acid igneous rocks. The rocks could be favorable for uranium accumulation and source rocks respectively. The aim of this study is to understand the uranium geology, radiometric and geochemical anomalies distribution and it to delineate the prospective area to uranium accumulation. Method of this study field geological observations, radiometric measurements, stream sediment and heavy mineral concentrate sampling, mineralogical and geochemical laboratory analysis. Litho logically, the area composed of slate (Early Yurassic), schist and phyllite (Triassic) and meta calcareous marl (Cretaceous). Those rocks un conformably overly by black siltstone and sandstone (Eocene) conglomerate sandstone (Late Oligocene-Early Miocene) siltstone (Middle Miocene). Some intrusions have been identified as biotite granodiorite (Cretaceous) porphyritic granodiorite (Eocene) and Olivine basalt (Middle Miocene-late Miocene). The rock have been faulted by dextral strike slip fault NW-SE, thrust fault NW-SE, sinistral; strike slip fault NE-SW, and normal faults WNW-ESE. Radioactivity value of rocks range between 40-100 cps SPP2NF and it contains is range about 0.36-150.84 ppm U. The geochemical prospect area has been defined at the area of 93.186 km 2

Star formations rates in the Galaxy

International Nuclear Information System (INIS)

Smith, L.F.; Mezger, P.G.; Biermann, P.

1978-01-01

Data relevant to giant HII regions in the Galaxy are collected. The production rate for Lyman continuum photons by O stars in giant HII regions is 4.7 10 52 s -1 in the whole Galaxy. The corresponding present rate of star formation is M (sun)/yr, of which 74% occurs in main spiral arms, 13% in the interarm region and 13% in the galactic center. The star formation rates, the observed heavy element and deuterium abundances in the solar neighbourhood are compared to model predictions based on star formation proportional to a power (k) of the gas surface density. The mass function is terminated at Msub(u)=100 M (sun) above and M 1 below. Msub(u)=50 M (sun) is also considered. Comparing with data derived from observations a) the star formation rate, b) metal abundances, c) deuterium abundances, and d) colors of the stellar population, we find that models of k=1/2 to 1, and M 1 1 M (sun) are formed together with O and B stars, but under rather special conditions of the interstellar gas, while lower mass stars form wherever dense molecular clouds exist. The high rate of star formation in the galactic center may represent a burst. (orig.) [de

INSTITUTIONAL ENVIRONMENT OF THE AGRICULTURAL MARKET FORMATION PROCESS

Directory of Open Access Journals (Sweden)

S. Revenko

2013-11-01

Full Text Available This article considers institutional aspects of the organized agricultural market formation process. Theoretical base to distinguish institute and institutes is given. In order to find out main influential institutes of the “organization” phenomenon author analyses Ukrainian institutional environment that is under construction process. Author considers main processes which are running during the organized market formation. Author researches theoretical approaches to the institutional staff. In order to structure the most common approaches and theoretical knowledge of this problem author proposes few schemes. Author’s points of view for many questions of the organized market formation process are proposed. Researcher analyzes effectiveness of the institutes and governmental regulation of the agricultural market. Readers can find strategically new approach to the agricultural market formation policy from the governmental point of view. Essence of the socioeconomic formation of agricultural market is considered. Main factors of agriculture market formation are outlined. Agricultural market structural parts consideration systematic approach is proposed. Ineffectiveness of the agriculture market relations without regulation process is proved. The most unfavorable reasons of the agricultural market formation are determined.

Recombinant human bone morphogenetic protein induces bone formation

International Nuclear Information System (INIS)

Wang, E.A.; Rosen, V.; D'Alessandro, J.S.; Bauduy, M.; Cordes, P.; Harada, T.; Israel, D.I.; Hewick, R.M.; Kerns, K.M.; LaPan, P.; Luxenberg, D.P.; McQuaid, D.; Moutsatsos, I.K.; Nove, J.; Wozney, J.M.

1990-01-01

The authors have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 μg of partially purified recombinant human BMP-2A resulted in cartilage by day 7 and bone formation by day 14. The time at which bone formation occurred was dependent on the amount of BMP-2A implanted; at high doses bone formation could be observed at 5 days. The cartilage- and bone-inductive activity of the recombinant BMP-2A is histologically indistinguishable from that of bone extracts. Thus, recombinant BMP-2A has therapeutic potential to promote de novo bone formation in humans

Formation, Sintering and Removal of Biomass Ash Deposits

DEFF Research Database (Denmark)

Laxminarayan, Yashasvi

conditions in laboratory-scale setups. Deposit formation was simulated in an Entrained Flow Reactor, to investigate the effect of operating conditions and ash chemistry on the rate of deposit formation. Experiments were performed using model biomass fly ash, prepared from mixtures of K2Si4O9, KCl, K2SO4, Ca....... Moreover, biomass ash deposits may cause severe corrosion of boiler surfaces. Therefore, reducing deposit formation and timely deposit removal are essential for optimal boiler operation. The formation, sintering and removal of boiler deposits has been investigated in this PhD project, by simulating boiler...... temperature increased the sticking probability of the fly ash particles/deposit surface, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, it was observed...

Thermoluminescence dating of Rio Claro and Piracununga formations

International Nuclear Information System (INIS)

Ferreira, Sandra Regina; Chang, Maria Rita Caetano

2008-01-01

The Rio Claro and Piracununga formations cover extensive areas of the Paulista Peripheral Depression, dominantly in the region of Rio Claro and Piracununga cities. These units lie over the Corumbatai and Piramboia formations, exhibiting discordant contacts. The Rio Claro and Piracununga formations are composed of fine to medium sand facies, showing local cross-stratifications and parallel beddings with thin interbeddings of mud and gravel. These sands were dated by the Thermoluminescence Method, which indicated they were from the Pleistocene age. The oldest age (745,000 years BP) was found in deposits of the Rio Claro Formation; the other ages varied from 400,000 years BP to 145,000 years BP, for both formations. The youngest age (15,000 years BP - close to Pleistocene/ Holocene limit) was found in colluvial deposits, which rest on the Piracununga Formation. (author)

Temperature controlled formation of lead/acid batteries

Science.gov (United States)

Bungardt, M.

At present, standard formation programs have to accommodate the worst case. This is important, especially in respect of variations in climatic conditions. The standard must be set so that during the hottest weather periods the maximum electrolyte temperature is not exceeded. As this value is defined not only by the desired properties and the recipe of the active mass, but also by type and size of the separators and by the dimensions of the plates, general rules cannot be formulated. It is considered to be advantageous to introduce limiting data for the maximum temperature into a general formation program. The latter is defined so that under normal to good ambient conditions the shortest formation time is achieved. If required, the temperature control will reduce the currents employed in the different steps, according to need, and will extend the formation time accordingly. With computer-controlled formation, these parameters can be readily adjusted to suit each type of battery and can also be reset according to modifications in the preceding processing steps. Such a procedure ensures that: (i) the formation time is minimum under the given ambient conditions; (ii) in the event of malpractice ( e.g. actual program not fitting to size) the batteries will not be destroyed; (iii) the energy consumption is minimized (note, high electrolyte temperature leads to excess gassing). These features are incorporated in the BA/FOS-500 battery formation system developed by Digatron. The operational characteristics of this system are listed in Table 1.

Experimental study upon the effect of irradiation on callus formation of fracture. Observation of vascular alteration and callus formation

Energy Technology Data Exchange (ETDEWEB)

Saigusa, F [Nippon Dental Coll., Tokyo

1981-02-01

Irradiation effects on callus formation after bone fracture were studied in rats with fractured right lower extremity. Follow-up study was continued for 112 days since 3000 rad was irradiated to the fractured site 3 days after bone fracture. Callus formation was noted in both of the outer and inner part (bone marrow) of the diaphysis before 14 days after bone fracture, but it was slow and sparse compared with that of non-irradiated group. Callus formation tended to disappear gradually from the outside of the diaphysis after 28 days after bone fracture. Strong disturbance was found in the surrounding vascular system at this time. Inside of the diaphysis, callus formation was restricted the end of the fracture, where lamellar calluses fused together. Changes in vascular system remained until 56 days after bone fracture. Vascular distribution was most dense 28 days after bone fracture. In many of the calluses which have established fusion, findings suggested excessive calcification in the trabeculae. Vascular distribution at this time was sparse, vascular formation was markedly suppressed in the bone marrow, and very little vascular formation was found in the fractured edges of the bone.

Grammar-Based Specification and Parsing of Binary File Formats

Directory of Open Access Journals (Sweden)

William Underwood

2012-03-01

Full Text Available The capability to validate and view or play binary file formats, as well as to convert binary file formats to standard or current file formats, is critically important to the preservation of digital data and records. This paper describes the extension of context-free grammars from strings to binary files. Binary files are arrays of data types, such as long and short integers, floating-point numbers and pointers, as well as characters. The concept of an attribute grammar is extended to these context-free array grammars. This attribute grammar has been used to define a number of chunk-based and directory-based binary file formats. A parser generator has been used with some of these grammars to generate syntax checkers (recognizers for validating binary file formats. Among the potential benefits of an attribute grammar-based approach to specification and parsing of binary file formats is that attribute grammars not only support format validation, but support generation of error messages during validation of format, validation of semantic constraints, attribute value extraction (characterization, generation of viewers or players for file formats, and conversion to current or standard file formats. The significance of these results is that with these extensions to core computer science concepts, traditional parser/compiler technologies can potentially be used as a part of a general, cost effective curation strategy for binary file formats.

General certification procedure of formation organizations

CERN Document Server

Int. At. Energy Agency, Wien

2002-01-01

This document presents the procedure dealing with the certification of formation organizations dispensing the formation and the risks prevention to the personnel of A or B category in nuclear facilities. This certification proves the organization ability to satisfy the ''F'' specification of the CEFRI. (A.L.B.)

Spur Reaction Model of Positronium Formation

DEFF Research Database (Denmark)

Mogensen, O. E.

1974-01-01

A new model of positronium (Ps) formation is proposed. Positronium is assumed to be formed by a reaction between a positron and an electron in the positron spur. Ps formation must compete with electron‐ion recombination and electron or positron reactions with solvent molecules and scavenger...

Exoplanets Detection, Formation, Properties, Habitability

CERN Document Server

Mason, John W

2008-01-01

This edited, multi-author volume will be an invaluable introduction and reference to all key aspects in the field of exoplanet research. The reviews cover: Detection methods and properties of known exoplanets, Detection of extrasolar planets by gravitational microlensing. The formation and evolution of terrestrial planets in protoplanetary and debris disks. The brown dwarf-exoplanet connection. Formation, migration mechanisms and properties of hot Jupiters. Dynamics of multiple exoplanet systems. Doppler exoplanet surveys. Searching for exoplanets in the stellar graveyard. Formation and habitability of extra solar planets in multiple star systems. Exoplanet habitats and the possibilities for life. Moons of exoplanets: habitats for life. Contributing authors: •Rory Barnes •David P. Bennett •Jian Ge •Nader Haghighipour •Patrick Irwin •Hugh Jones •Victoria Meadows •Stanimir Metchev •I. Neill Reid •George Rieke •Caleb Scharf •Steinn Sigurdsson

Modularity in New Market Formation

DEFF Research Database (Denmark)

Sanchez, Ron; Hang, Chang Chieh

2017-01-01

In this paper we appraise the ways in which use of closed-system proprietary product architectures versus open-system modular product architectures is likely to influence the dynamics and trajectory of new product market formation. We compare the evolutions of new markets in China for gas......-powered two-wheeled vehicles (G2WVs) based (initially) on closed-system proprietary architectures and for electric-powered two-wheeled vehicles (E2WVs) based on open-system modular architectures. We draw on this comparison to suggest ways in which the use of the two different kinds of architectures...... as the basis for new kinds of products may result in very different patterns and speeds of new market formation. We then suggest some key implications of the different dynamics of market formation associated with open-system modular architectures for both the competence-based strategic management (CBSM...

Star Cluster Structure from Hierarchical Star Formation

Science.gov (United States)

Grudic, Michael; Hopkins, Philip; Murray, Norman; Lamberts, Astrid; Guszejnov, David; Schmitz, Denise; Boylan-Kolchin, Michael

2018-01-01

Young massive star clusters (YMCs) spanning 104-108 M⊙ in mass generally have similar radial surface density profiles, with an outer power-law index typically between -2 and -3. This similarity suggests that they are shaped by scale-free physics at formation. Recent multi-physics MHD simulations of YMC formation have also produced populations of YMCs with this type of surface density profile, allowing us to narrow down the physics necessary to form a YMC with properties as observed. We show that the shallow density profiles of YMCs are a natural result of phase-space mixing that occurs as they assemble from the clumpy, hierarchically-clustered configuration imprinted by the star formation process. We develop physical intuition for this process via analytic arguments and collisionless N-body experiments, elucidating the connection between star formation physics and star cluster structure. This has implications for the early-time structure and evolution of proto-globular clusters, and prospects for simulating their formation in the FIRE cosmological zoom-in simulations.

Septum formation of the lateral ventricles

International Nuclear Information System (INIS)

Celik, Hakan H.; Aldur, Mustafa M.; Tatar, I.; Tascioglu, A.B.

2005-01-01

In an MRI study examining anomalies of the septum pellucidum in 505 cases, we detected bilateral septum formation of the lateral ventricles in a 17-months-old-baby. In this study, we evaluate 505 (242 males and 263 females) patients referred to the Emaray Imaging Center, Ankara, Turkey with various prediagnoses. We specially selected all the cases from a non-psychotic population. We obtained MRI scans on a 1-Tesla imager (Picker International, Highland Heights, Ohio, USA), with slices of 5 and 6 mm thickness. In the axial and coronal sections, we observed septum formation laterally between the anterior horn and the ventricular body of the lateral ventricles. Radio opaque septum formations started from the caudate nucleus and stretched to the genu of the corpus callosum. There was a second septum formation between the posterior horn and the ventricular body of the right lateral ventricle. It started from the caudate nucleus and stretched to the cavum vergae. (author)

Theoretical Aspects of Enterprise Business Strategy Formation

OpenAIRE

Valentinavičius, Stasys

2009-01-01

The paper presents interpretations of business strategy concept and analyses strategy planning and formation, models. The concept of business strategy is revised and formulated considering various authors approaches. Analysis of business strategy formation process – steps of development and management, selection of strategy type – is based on presented strategy planning models. The aspects of enterprise business and investment strategy formation, coordination and valuation are analysed. The s...

Formation rate of natural gas hydrate

Energy Technology Data Exchange (ETDEWEB)

Mork, Marit

2002-07-01

The rate of methane hydrate and natural gas hydrate formation was measured in a 9.5 litre stirred tank reactor of standard design. The experiments were performed to better understand the performance and scale-up of a reactor for continuous production of natural gas hydrates. The hydrate formation rate was measured at steady-state conditions at pressures between 70 and 90 bar and temperatures between 7 and 15 deg C. Between 44 and 56 % of the gas continuously supplied to the reactor was converted to hydrate. The experimental results show that the rate of hydrate formation is strongly influenced by gas injection rate and pressure. The effect of stirring rate is less significant and subcooling has no observable effect on the formation rate. Hydrate crystal concentration and gas composition do not influence the hydrate formation rate. Observations of produced hydrate crystals indicate that the crystals are elongated, about 5 micron in diameter and 10 micron long. Analysis of the results shows that the rate of hydrate formation is dominated by gas-liquid mass transfer. A mass transfer model, the bubble-to-crystal model, was developed for the hydrate formation rate in a continuous stirred tank reactor, given in terms of concentration driving force and an overall mass transfer coefficient. The driving force is the difference between the gas concentration at the gas-liquid interface and at the hydrate crystal surface. These concentrations correspond to the solubility of gas in water at experimental temperature and pressure and the solubility of gas at hydrate equilibrium temperature and experimental pressure, respectively. The overall mass transfer coefficient is expressed in terms of superficial gas velocity and impeller power consumption, parameters commonly used in study of stirred tank reactors. Experiments and modeling show that the stirred tank reactor has a considerable potential for increased production capacity. However, at higher hydrate production rates the

The multifaceted planetesimal formation process

DEFF Research Database (Denmark)

Johansen, Anders; Blum, Jürgen; Tanaka, Hidekazu

2013-01-01

Accumulation of dust and ice particles into planetesimals is an important step in the planet formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores of gas and ice giants forming by core accretion. Left-over planetesimals in the form of asteroids, trans...... for planetesimal formation where particle growth starts unaided by self-gravity but later proceeds inside gravitationally collapsing pebble clumps to form planetesimals with a wide range of sizes....

Ministerial formation of theological students through distance education

Directory of Open Access Journals (Sweden)

Marilyn Naidoo

2012-02-01

Full Text Available Ministerial formation is a multifaceted activity involving critical thinking, the acquisition of knowledge, skills development, religious identity formation and the development of ministerial and spiritual maturity expected of church ministers. Education is not merely the accumulation of a prescribed set of academic credits but includes the holistic formation of all aspects of the individual. However, theological educators are concerned about the capacity to foster such values and skills in the distance and electronic environment. Some see distance education as ‘distancing’ the students in more significant ways than simply geographic distance. These issues are of fundamental importance for they reflect the deeper convictions of theologians that distance education may not be a suitable medium for ministerial formation. This article creates a conceptual map of the theological and pedagogical challenges for ministerial formation and highlights how the possibility of formation is being carried out in the distance-learning environment.

Formation and evolution of compact binaries

NARCIS (Netherlands)

Sluijs, Marcel Vincent van der

2006-01-01

In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

Converting Taxonomic Descriptions to New Digital Formats

Directory of Open Access Journals (Sweden)

Hong Cui

2008-01-01

Full Text Available Abstract.--The majority of taxonomic descriptions is currently in print format. The majority of digital descriptions are in formats such as DOC, HTML, or PDF and for human readers. These formats do not convey rich semantics in taxonomic descriptions for computer-aided process. Newer digital formats such as XML and RDF accommodate semantic annotations that allow computers to process the rich semantics on human's behalf, thus open up opportunities for a wide range of innovative usages of taxonomic descriptions, such as searching in more precise and flexible ways, integrating with gnomic and geographic information, generating taxonomic keys automatically, and text data mining and information visualization etc. This paper discusses the challenges in automated conversion of multiple collections of descriptions to XML format and reports an automated system, MARTT. MARTT is a machine-learning system that makes use of training examples to tag new descriptions into XML format. A number of utilities are implemented as solutions to the challenges. The utilities are used to reduce the effort for training example preparation, to facilitate the creation of a comprehensive schema, and to predict system performance on a new collection of descriptions. The system has been tested with several plant and alga taxonomic publications including Flora of China and Flora of North America.

Superclusters and galaxy formation

International Nuclear Information System (INIS)

Einasto, J.; Joeveer, M.; Saar, E.

1979-01-01

The spatial distribution of Galaxies and Galaxy congestions in the southern galactic hemisphere is studied. The rich galaxy congestions, containing many elliptic Galaxies and radiogalaxies, are linked with each other by chains of scanty congestions with moderate content of elliptic Galaxies and radiogalaxies. The flat formation, linking the density pikes and the intermediate chains, can reasonably be called supercongestion. In the central region of supercongestions there is a thin layer of Galaxies consisting of only spiral Galaxies. The neighbouring supercongestions touch each other, while the intersupercongestion space contains no Galaxy congestions and almost no Galaxies. It is shown that such a structure was, apparently, formed before the formation of Galaxies

Implication of formative assessment practices among mathematics teacher

Science.gov (United States)

Samah, Mas Norbany binti Abu; Tajudin, Nor'ain binti Mohd

2017-05-01

Formative assessment of school-based assessment (SBA) is implemented in schools as a move to improve the National Education Assessment System (NEAS). Formative assessment focuses on assessment for learning. There are various types of formative assessment instruments used by teachers of mathematics, namely the form of observation, questioning protocols, worksheets and quizzes. This study aims to help teachers improve skills in formative assessments during the teaching and learning (t&l) Mathematics. One mathematics teacher had been chosen as the study participants. The collecting data using document analysis, observation and interviews. Data were analyzed narrative and assessments can help teachers implement PBS. Formative assessment is conducted to improve the skills of students in t&l effectively.

MILLIMETER WAVE SPECTRUM AND ASTRONOMICAL SEARCH FOR VINYL FORMATE

Energy Technology Data Exchange (ETDEWEB)

Alonso, E. R.; Kolesniková, L.; Cabezas, C.; Alonso, J. L. [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Área de Química-Física, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid (Spain); Tercero, B.; Cernicharo, J. [Grupo de Astrofísica Molecular, ICMM-CSIC, C/Sor Juana Inés de la Cruz 3, E-28049 Cantoblanco (Spain); Guillemin, J.-C. [Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, F-35708 Rennes Cedex 7 (France)

2016-11-20

Previous detections of methyl and ethyl formate make other small substituted formates potential candidates for observation in the interstellar medium. Among them, vinyl formate is one of the simplest unsaturated carboxylic ester. The aim of this work is to provide direct experimental frequencies of the ground vibrational state of vinyl formate in a large spectral range for astrophysical use. The room-temperature rotational spectrum of vinyl formate has been measured from 80 to 360 GHz and analyzed in terms of Watson’s semirigid rotor Hamiltonian. Two thousand six hundred transitions within J = 3–88 and K {sub a} = 0–28 were assigned to the most stable conformer of vinyl formate and a new set of spectroscopic constants was accurately determined. Spectral features of vinyl formate were then searched for in Orion KL, Sgr B2(N), B1-b, and TMC-1 molecular clouds. Upper limits to the column density of vinyl formate are provided.

On the formation of sulphuric acid – amine clusters in varying atmospheric conditions and its influence on atmospheric new particle formation

Directory of Open Access Journals (Sweden)

I. K. Ortega

2012-10-01

Full Text Available Sulphuric acid is a key component in atmospheric new particle formation. However, sulphuric acid alone does not form stable enough clusters to initiate particle formation in atmospheric conditions. Strong bases, such as amines, have been suggested to stabilize sulphuric acid clusters and thus participate in particle formation. We modelled the formation rate of clusters with two sulphuric acid and two amine molecules (JA2B2 at varying atmospherically relevant conditions with respect to concentrations of sulphuric acid ([H2SO4], dimethylamine ([DMA] and trimethylamine ([TMA], temperature and relative humidity (RH. We also tested how the model results change if we assume that the clusters with two sulphuric acid and two amine molecules would act as seeds for heterogeneous nucleation of organic vapours (other than amines with higher atmospheric concentrations than sulphuric acid. The modelled formation rates JA2B2 were functions of sulphuric acid concentration with close to quadratic dependence, which is in good agreement with atmospheric observations of the connection between the particle formation rate and sulphuric acid concentration. The coefficients KA2B2 connecting the cluster formation rate and sulphuric acid concentrations as JA2B2=KA2B2[H2SO4]2 turned out to depend also on amine concentrations, temperature and relative humidity. We compared the modelled coefficients KA2B2 with the corresponding coefficients calculated from the atmospheric observations (Kobs from environments with varying temperatures and levels of anthropogenic influence. By taking into account the modelled behaviour of JA2B2 as a function of [H2SO4], temperature and RH, the atmospheric particle formation rate was reproduced more closely than with the traditional semi-empirical formulae based on sulphuric acid concentration only. The formation rates of clusters with two sulphuric acid and two amine molecules with different amine compositions (DMA or TMA or one of both had

Fostering Spiritual Formation of Millennials in Christian Schools

Science.gov (United States)

Horan, Anne Puidk

2017-01-01

Christian education seeks to foster millennials' spiritual formation to equip them for future challenges and to benefit society. Using nonexperimental mixed methods, 504 secondary educators revealed what spiritual formation programs their schools implement and their perceptions about millennial spiritual formation. Descriptive analysis showed that…

Inhibition of the anaerobic acetate degradation by formate

OpenAIRE

Guyot, Jean-Pierre; Ramirez, F.

1989-01-01

Granular sludge from an UASB reactor fed with VFA showed a very low affinity for formate which provide little support to the theory of interspecies formate transfer. It is shown that formate can inhibit acetate degradation by anaerobic sludge. (Résumé d'auteur)

The formation mechanism of lactones in Gouda cheese

NARCIS (Netherlands)

Alewijn, M.; Smit, B.; Sliwinski, E.L.; Wouters, J.T.M.

2007-01-01

Lactones are fat-derived aroma compounds, but the formation mechanism of these compounds during ripening of Gouda cheese is unknown. Both enzymatic and chemical formation pathways were investigated in this study. Lactone formation from milk triglycerides or free fatty acids by lactic acid bacteria

Aggregate formation in 3D turbulent-like flows

NARCIS (Netherlands)

Dominguez, A.; Clercx, H.J.H.

2006-01-01

Aggregate formation is an important process in industrial and environmental turbulent flows. In oceans turbulence play an important role on Marine Snow (aggregate) formation. For a proper description, the study of aggregate formation in turbulent flows requires a particle based model i.e. following

Time-Dependent Dust Formation in Novae

Directory of Open Access Journals (Sweden)

Kyung-Won Suh

1991-06-01

Full Text Available The dust formation processes in novae are investigated with close attention to recent infrared observations. Using mainly the classical nucleation theory, we have calculated the time scales of dust formation and growth in the environments of novae. Those time scales roughly resemble the typical observations. We have classified the dust-forming novae into three classes according to their explosion properties and the thermodynamic properties of dust grains. Oxygen grains from much later than carbon grains because of their thermodynamic properties. The effect of grain formation to the efficiency of stellar winds to drive the material outward is tested with newly obtained Planck mean values of dust grains.

Formation enthalpy of alkali-borosilicate glass

International Nuclear Information System (INIS)

Borisova, N.V.; Ushakov, V.M.

1991-01-01

Temperature dependence of formation enthalpy of glass of the composition 0.0438Na 2 O-0.0385K 2 O-0.3394B 2 O 3 -0.5783SiO 2 was determined using the method of high-temperature colorimetry-dissolution, mixing and differential scanning calorimetry. The glass considered has liquation nature-two-vitrification ranges at 713 K and 817 K are detected. The brightening point is 922 K. The calculation of formation enthalpy using the method of partial heat capacities is made in the temperature range of 973-1473 K. Formation enthalpy does not depend on temperature in the temperature range of 298-1273 K

New method for determination of star formation history

OpenAIRE

Čeponis, Marius

2017-01-01

A New Method for Determination of Star Formation History Without stars there would not be any life and us. Almost all elements in our bodies are made in stars. Yet we still don‘t fully understand all the processes governing formation and evolution of stellar systems. Their star formation histories really help in trying to understand these processes. In this work a new Bayesian method for determination of star formation history is proposed. This method uses photometric data of resolved stars a...

Efficient stereoscopic contents file format on the basis of ISO base media file format

Science.gov (United States)

Kim, Kyuheon; Lee, Jangwon; Suh, Doug Young; Park, Gwang Hoon

2009-02-01

A lot of 3D contents haven been widely used for multimedia services, however, real 3D video contents have been adopted for a limited applications such as a specially designed 3D cinema. This is because of the difficulty of capturing real 3D video contents and the limitation of display devices available in a market. However, diverse types of display devices for stereoscopic video contents for real 3D video contents have been recently released in a market. Especially, a mobile phone with a stereoscopic camera has been released in a market, which provides a user as a consumer to have more realistic experiences without glasses, and also, as a content creator to take stereoscopic images or record the stereoscopic video contents. However, a user can only store and display these acquired stereoscopic contents with his/her own devices due to the non-existence of a common file format for these contents. This limitation causes a user not share his/her contents with any other users, which makes it difficult the relevant market to stereoscopic contents is getting expanded. Therefore, this paper proposes the common file format on the basis of ISO base media file format for stereoscopic contents, which enables users to store and exchange pure stereoscopic contents. This technology is also currently under development for an international standard of MPEG as being called as a stereoscopic video application format.

Cosmic strings and galaxy formation

Science.gov (United States)

Bertschinger, Edmund

1989-01-01

The cosmogonical model proposed by Zel'dovich and Vilenkin (1981), in which superconducting cosmic strings act as seeds for the origin of structure in the universe, is discussed, summarizing the results of recent theoretical investigations. Consideration is given to the formation of cosmic strings, the microscopic structure of strings, gravitational effects, cosmic string evolution, and the formation of galaxies and large-scale structure. Simulation results are presented in graphs, and several outstanding issues are listed and briefly characterized.

Star formation in evolving molecular clouds

Science.gov (United States)

Völschow, M.; Banerjee, R.; Körtgen, B.

2017-09-01

Molecular clouds are the principle stellar nurseries of our universe; they thus remain a focus of both observational and theoretical studies. From observations, some of the key properties of molecular clouds are well known but many questions regarding their evolution and star formation activity remain open. While numerical simulations feature a large number and complexity of involved physical processes, this plethora of effects may hide the fundamentals that determine the evolution of molecular clouds and enable the formation of stars. Purely analytical models, on the other hand, tend to suffer from rough approximations or a lack of completeness, limiting their predictive power. In this paper, we present a model that incorporates central concepts of astrophysics as well as reliable results from recent simulations of molecular clouds and their evolutionary paths. Based on that, we construct a self-consistent semi-analytical framework that describes the formation, evolution, and star formation activity of molecular clouds, including a number of feedback effects to account for the complex processes inside those objects. The final equation system is solved numerically but at much lower computational expense than, for example, hydrodynamical descriptions of comparable systems. The model presented in this paper agrees well with a broad range of observational results, showing that molecular cloud evolution can be understood as an interplay between accretion, global collapse, star formation, and stellar feedback.

Delayed star formation in isolated dwarf galaxies: Hubble space telescope star formation history of the Aquarius dwarf irregular

Energy Technology Data Exchange (ETDEWEB)

Cole, Andrew A. [School of Physical Sciences, University of Tasmania, Private Bag 37, Hobart, Tasmania, 7001 Australia (Australia); Weisz, Daniel R. [Department of Astronomy, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Dolphin, Andrew E. [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States); Skillman, Evan D. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55441 (United States); McConnachie, Alan W. [NRC Herzberg Institute of Astrophysics, Dominion Astrophysical Observatory, Victoria, BC, V9E 2E7 Canada (Canada); Brooks, Alyson M. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Leaman, Ryan, E-mail: andrew.cole@utas.edu.au, E-mail: drw@ucsc.edu, E-mail: adolphin@raytheon.com, E-mail: skillman@astro.umn.edu, E-mail: alan.mcconnachie@nrc-cnrc.gc.ca, E-mail: abrooks@physics.rutgers.edu, E-mail: rleaman@iac.es [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

2014-11-01

We have obtained deep images of the highly isolated (d = 1 Mpc) Aquarius dwarf irregular galaxy (DDO 210) with the Hubble Space Telescope Advanced Camera for Surveys. The resulting color-magnitude diagram (CMD) reaches more than a magnitude below the oldest main-sequence turnoff, allowing us to derive the star formation history (SFH) over the entire lifetime of the galaxy with a timing precision of ≈10% of the lookback time. Using a maximum likelihood fit to the CMD we find that only ≈10% of all star formation in Aquarius took place more than 10 Gyr ago (lookback time equivalent to redshift z ≈ 2). The star formation rate increased dramatically ≈6-8 Gyr ago (z ≈ 0.7-1.1) and then declined until the present time. The only known galaxy with a more extreme confirmed delay in star formation is Leo A, a galaxy of similar M {sub H} {sub I}/M {sub *}, dynamical mass, mean metallicity, and degree of isolation. The delayed stellar mass growth in these galaxies does not track the mean dark matter accretion rate from CDM simulations. The similarities between Leo A and Aquarius suggest that if gas is not removed from dwarf galaxies by interactions or feedback, it can linger for several gigayears without cooling in sufficient quantity to form stars efficiently. We discuss possible causes for the delay in star formation including suppression by reionization and late-time mergers. We find reasonable agreement between our measured SFHs and select cosmological simulations of isolated dwarfs. Because star formation and merger processes are both stochastic in nature, delayed star formation in various degrees is predicted to be a characteristic (but not a universal) feature of isolated small galaxies.

Problems of Kazakh Literary Criticism Formation

Directory of Open Access Journals (Sweden)

Zhandos Smagulov

2013-01-01

Full Text Available Тhe article is concerned with the problem of scientific research of Kazakh literature formation in national science. Kazakh literature, having long history of formation is classified by periods. Besides, the article thoroughly considers the principles of the study of methodology, theory, history of spiritual heritage in Kazakh literary criticism

The Role of Trust in Costly Network Formation

NARCIS (Netherlands)

Gilles, R.P.; Sarangi, S.

2003-01-01

We consider game theoretic models of social network formation.In this paper we limit our investigation to game theoretic models of network formation that are based on individual actions only.Our approach is based on three simple and realistic principles: (1) Link formation is a binary process of

Star formation in the outskirts of disk galaxies

NARCIS (Netherlands)

Ferguson, AMN

2002-01-01

The far outer regions of galactic disks allow an important probe of both star formation and galaxy formation. I discuss how observations of HII regions in these low gas density, low metallicity environments can shed light on the physical processes which drive galactic star formation. The history of

Formation of stars and stellar clusters in galactic environment

OpenAIRE

Smilgys, Romas

2018-01-01

Star and stellar cluster formation in spiral galaxies is one of the biggest questions of astrophysics. In this thesis, I study how star formation, and the formation of stellar clusters, proceeds using SPH simulations. These simulations model a region of 400 pc and 10⁷ solar masses. Star formation is modelled through the use of sink particles which represent small groups of stars. Star formation occurs in high density regions, created by galactic spiral arm passage. The spiral shock compresses...

A Faculty Toolkit for Formative Assessment in Pharmacy Education.

Science.gov (United States)

DiVall, Margarita V; Alston, Greg L; Bird, Eleanora; Buring, Shauna M; Kelley, Katherine A; Murphy, Nanci L; Schlesselman, Lauren S; Stowe, Cindy D; Szilagyi, Julianna E

2014-11-15

This paper aims to increase understanding and appreciation of formative assessment and its role in improving student outcomes and the instructional process, while educating faculty on formative techniques readily adaptable to various educational settings. Included are a definition of formative assessment and the distinction between formative and summative assessment. Various formative assessment strategies to evaluate student learning in classroom, laboratory, experiential, and interprofessional education settings are discussed. The role of reflective writing and portfolios, as well as the role of technology in formative assessment, are described. The paper also offers advice for formative assessment of faculty teaching. In conclusion, the authors emphasize the importance of creating a culture of assessment that embraces the concept of 360-degree assessment in both the development of a student's ability to demonstrate achievement of educational outcomes and a faculty member's ability to become an effective educator.

Formatting Open Science: agilely creating multiple document formats for academic manuscripts with Pandoc Scholar

Directory of Open Access Journals (Sweden)

Albert Krewinkel

2017-05-01

Full Text Available The timely publication of scientific results is essential for dynamic advances in science. The ubiquitous availability of computers which are connected to a global network made the rapid and low-cost distribution of information through electronic channels possible. New concepts, such as Open Access publishing and preprint servers are currently changing the traditional print media business towards a community-driven peer production. However, the cost of scientific literature generation, which is either charged to readers, authors or sponsors, is still high. The main active participants in the authoring and evaluation of scientific manuscripts are volunteers, and the cost for online publishing infrastructure is close to negligible. A major time and cost factor is the formatting of manuscripts in the production stage. In this article we demonstrate the feasibility of writing scientific manuscripts in plain markdown (MD text files, which can be easily converted into common publication formats, such as PDF, HTML or EPUB, using Pandoc. The simple syntax of Markdown assures the long-term readability of raw files and the development of software and workflows. We show the implementation of typical elements of scientific manuscripts—formulas, tables, code blocks and citations—and present tools for editing, collaborative writing and version control. We give an example on how to prepare a manuscript with distinct output formats, a DOCX file for submission to a journal, and a LATEX/PDF version for deposition as a PeerJ preprint. Further, we implemented new features for supporting ‘semantic web’ applications, such as the ‘journal article tag suite’—JATS, and the ‘citation typing ontology’—CiTO standard. Reducing the work spent on manuscript formatting translates directly to time and cost savings for writers, publishers, readers and sponsors. Therefore, the adoption of the MD format contributes to the agile production of open science

Self-regulating star formation and disk structure

International Nuclear Information System (INIS)

Dopita, M.A.

1987-01-01

Star formation processes determine the disk structure of galaxies. Stars heavier than about 1 solar mass determine the chemical evolution of the system and are produced at a rate which maintains (by the momentum input of the stars) the phase structure, pressure, and vertical velocity dispersion of the gas. Low mass stars are produced quiescently within molecular clouds, and their associated T-Tauri winds maintain the support of molecular clouds and regulate the star formation rate. Inefficient cooling suppresses this mode of star formation at low metallicity. Applied to the solar neighborhood, such a model can account for age/metallicity relationships, the increase in the O/Fe ratio at low metallicity, the paucity of metal-poor G and K dwarf stars, the missing mass in the disk and, possibly, the existence of a metal-poor thick disk. For other galaxies, it accounts for constant w-velocity dispersion of the gas, the relationship between gas content and specific rates of star formation, the surface brightness/metallicity relationship and for the shallow radial gradients in both star formation rates and HI content. 71 references

Requirements for a next generation nuclear data format

International Nuclear Information System (INIS)

Archier, Pascal; Jouanne, Cedric; Peneliau, Yannick; Saint-Jean, Cyrille de; Trama, Jean-Christophe; Becky, Bret; Cullen, D.E. Red; Mattoony, Caleb; McNabb, Dennis; Brownyz, David; Herman, Michal; Johnson, Timothy; Sonzogni, Alejandro; Cabellos, Oscar; Capote Noy, Roberto; Forrest, Robin; Trkov, Andrej; Zerkiny, Viktor; Go, Chiba; Conliny, Jeremy Lloyd; Kahler, A.H. Skip; Talouy, Patrick; Whitey, Morgan C.; Cornock, Mark; Coste-Delclaux, Mireille; Malvagi, Fausto; Dunn, Michael; Leal, Luiz; Pigni, Marco; Wiarda, Dorothea; Dupont, Emmeric; Fischer, Ulrich; Tokio, Fukahori; Makoto, Ishikawa; Osamu, Iwamoto; Chikara, Konno; Teruhiko, Kugo; Kenji, Nishihara; Tatsuhiko, Sato; Kenya, Suyama; Kenji, Yokoyama; Haeck, Wim; Hawari, Ayman; Holmes, Jessie; Jacqmin, Robert; Noguere, Gilles; Kodeli, Ivo; Koningy, Arjan; Lee, Morgan; Sublet, Jean-Christophe; Lubitz, Cecil; Romano, Paul; Millsy, Robert; Roubtsovy, Danila; Scopatz, Anthony; Sinitsa, Valentin; Soppera, Nicolas; Vogty, Romona

2015-01-01

This document attempts to compile the requirements for the top-levels of a hierarchical arrangement of nuclear data such as is found in the ENDF format. This set of requirements will be used to guide the development of a new set of formats to replace the legacy ENDF format. (authors)

Modeling of tethered satellite formations using graph theory

DEFF Research Database (Denmark)

Larsen, Martin Birkelund; Smith, Roy S; Blanke, Mogens

2011-01-01

satellite formation and proposes a method to deduce the equations of motion for the attitude dynamics of the formation in a compact form. The use of graph theory and Lagrange mechanics together allows a broad class of formations to be described using the same framework. A method is stated for finding...

Probes of Cosmic Star Formation History

Indian Academy of Sciences (India)

I summarize X-ray diagnostic studies of cosmic star formation history in terms of evolutionary schemes for X-ray binary evolution in normal galaxies with evolving star formation. Deep X-ray imaging studies by Chandra and XMM-Newton are now beginning to constrain both the X-ray luminosity evolution of galaxies and the ...

Seroma formation after surgery for breast cancer

Directory of Open Access Journals (Sweden)

Ebrahimi Mandana

2004-12-01

Full Text Available Abstract Background Seroma formation is the most frequent postoperative complication after breast cancer surgery. We carried out a study to investigate the effect of various demographic, clinical and therapeutic variables on seroma formation. Patients and methods A retrospective cross sectional study of patients who underwent surgical therapy for breast cancer with either modified radical mastectomy (MRM or breast preservation (BP was carried out. The demographic data and clinical information were extracted from case records. Seroma formation was studied in relation to age, type of surgery, tumor size, nodal involvement, preoperative chemotherapy, surgical instrument (electrocautery or scalpel, use of pressure garment, and duration of drainage. The multiple logistic regression analysis was performed to estimate odds ratios. Results A total of 158 patients with breast cancer were studied. The mean age of the patients was 46.3 years (SD ± 11.9. Seventy-three percent underwent modified radical mastectomy and the remaining 27% received breast preservation surgery. Seroma occurred in 35% of patients. In multivariate logistic regression analysis an association of postoperative seroma formation was noted with modified radical mastectomy (OR = 2.83, 95% CI 1.01–7.90, P = 0.04. No other factor studied was found to significantly effect the seroma formation after breast cancer surgery. Conclusion The findings suggest that the type of surgery is a predicting factor for seroma formation in breast cancer patients.

Method of treating non-supporting underground formations

International Nuclear Information System (INIS)

Anderson, B.W.; Trotty, K.D.

1977-01-01

Method of treating non-supporting underground formations, through which passes a borehole, aimed at preventing the transport of sand particles from the formation into the borehole during conveyance of liquids. (orig./RW) [de

Habit formation, work ethics, and technological progress

OpenAIRE

Faria, João Ricardo; León-Ledesma, Miguel A.

2002-01-01

Work ethics affects labor supply. This idea is modeled assuming that work is habit forming. This paper introduces working habits in a neoclassical growth model and compares its outcomes with a model without habit formation. In addition, it analyzes the impact of different forms of technical progress. The findings are that i) labor supply in the habit formation case is higher than in the neoclassical case; ii) unlike in the neoclassical case, labor supply in the presence of habit formation wil...

Negative ion formation and neutralization processes, (1)

International Nuclear Information System (INIS)

Sugiura, Toshio

1982-01-01

This review has been made preliminary for the purpose of contribute to the plasma heating by ''negative ion based neutral beam injection'' in the magnetic confinement fusion reactor. A compilation includes the survey of the general processes of negative ion formation, the data of the cross section of H - ion formation and the neutralization of H - ion, and some of new processes of H - ion formation. The data of cross section are mainly experimental, but partly include the results of theoretical calculation. (author)

Specific plant induced biofilm formation in Methylobacterium species

Science.gov (United States)

Rossetto, Priscilla B.; Dourado, Manuella N.; Quecine, Maria C.; Andreote, Fernando D.; Araújo, Welington L.; Azevedo, João L.; Pizzirani-Kleiner, Aline A.

2011-01-01

Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp. host recognition, biofilm formation and successful colonization as endophytes. PMID:24031703

Cosmic strings and galaxy formation

International Nuclear Information System (INIS)

Bertschinger, E.

1989-01-01

Cosmic strings have become increasingly popular candidates as seeds for the formation of structure in the universe. This scenario, remains a serious cosmogonical model despite close scrutiny. In constrast, magnetic monopoles and domain walls - relic topological defects as are cosmic strings - are disastrous for cosmology if they are left over from the early universe. The production of heavy cosmic strings is speculative, as it depends on the details of ultrahigh energy physics. Fortunately, speculation about cosmic strings is not entirely idle because, if they exist and are heavy enough to seed galaxy formation, cosmic strings can be detected astronomically. Failure to detect cosmic strings would impose some constraints on grand unified theories (GUTs); their discovery would have exciting consequences for high energy physics and cosmology. This article reviews the basic physics of nonsuperconducting cosmic strings, highlighting the field theory aspects, and provides a progress report on calculations of structure formation with cosmic strings

Unit Monitors Manchester-Format Data Buses

Science.gov (United States)

Amador, Jose J.

1994-01-01

Circuit card converts data signals into convenient hexadecimal form for troubleshooting. Bus-monitoring unit converts data signals from Manchester II format used on data bus into hexadecimal format. Monitoring circuit causes hexadecimal words to display on video terminal, where test engineer compares them with hexadecimal records for troubleshooting. Circuit monitors one bus or two buses simultaneously.

25 CFR 82.6 - Petition format.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Petition format. 82.6 Section 82.6 Indians BUREAU OF... REORGANIZED UNDER FEDERAL STATUTE AND OTHER ORGANIZED TRIBES § 82.6 Petition format. Petitions may consist of... of a petition must set forth at least a summary of the objectives of the petitioners and must show...

Triggered star formation

Czech Academy of Sciences Publication Activity Database

Palouš, Jan; Ehlerová, Soňa

2002-01-01

Roč. 12, - (2002), s. 35-36 ISSN 1405-2059 R&D Projects: GA AV ČR IAA3003705; GA AV ČR KSK1048102 Institutional research plan: CEZ:AV0Z1003909 Keywords : interstellar medium * star formation * HI shells Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

Microbial processes in banded iron formation deposition

DEFF Research Database (Denmark)

Posth, Nicole; Konhauser, Kurt; Kappler, Andreas

2013-01-01

, remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean......Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

Gravitational instability, evolution of galaxies and star formation

International Nuclear Information System (INIS)

Palous, J.

1979-01-01

The gravitational collapse is the key to the theories of galaxy and star formation. The observations, showing intrinsic differences between elliptical and spiral galaxies, guide our fundamental conceptions on the formation and evolution of systems in question. Stars in elliptical galaxies and in spherical components of spiral galaxies were formed in a short period of time during early phases of protogalactic collapse, at a time of violent star formation. The disc-like components of spiral galaxies, however, were built gradually in the course of galactic evolution. Star formation in elliptical galaxies is described by the collision model of interstellar clouds, while star formation in discs is characterised by several processes: the expansion of HII regions, the expansion of supernovae remnants and the shock wave related to the presence of the spiral structure. (author)

Seminary Formation: A Case Study from the Pontifical Beda College, Rome

Science.gov (United States)

Strange, Roderick

2015-01-01

This case study account reviews issues related to seminary formation and education at the Beda College, Rome, including Fundamentals of Formation, Community Life, Organizing Formation, Intellectual Formation, Spiritual Formation, Pastoral Formation, and the challenges arising in these fields.

Program X4TOC4 (Version 86-1). Translation of experimental data from the EXFOR format to a computation format

International Nuclear Information System (INIS)

Cullen, D.E.

1986-09-01

Experimental nuclear reaction data are world-wide compiled in EXFOR format. The computer program X4TOC4 described in the present document translates data from the rather flexible EXFOR format to the more rigid ''computation format'' which is suitable for input to further computer processing of the data including graphical plotting. The program is available costfree from the IAEA Nuclear Data Section, upon request. (author)

Creating and maintaining a gas cap in tar sands formations

Science.gov (United States)

Vinegar, Harold J.; Karanikas, John Michael; Dinkoruk, Deniz Sumnu; Wellington, Scott Lee

2010-03-16

Methods for treating a tar sands formation are disclosed herein. Methods for treating a tar sands formation may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. Pressure may be allowed to increase in an upper portion of the formation to provide a gas cap in the upper portion. At least some hydrocarbons are produced from a lower portion of the formation.

Dust formation and ionization in novae

International Nuclear Information System (INIS)

Yamamoto, Tetsuo; Sato, Shuji; Nariai, Kyoji.

1979-01-01

In order to explain the fact that some novae show the increase of infrared radiation indicating the formation of circumstellar dust grains while some others do not, the theory that the formation of dust in the circumstellar envelope of a nova depends on the intensity of ultraviolet radiation from a central star has been presented. It is known that the central star of a nova emits radiation at nearly constant rate, and its effective temperature rises. It was concluded that the novae with higher emission than a certain value are the poor candidates for dust formation because the whole envelope is ionized before dust is formed. But this conclusion is misleading. The evolution of the ultraviolet radiation emanating from a central star is summarized. The condensation of grains is possible when the partial pressure of the vapor, from which the grains are formed, becomes higher than the saturation vapor pressure. The temperature of grains can be estimated by equating the radiations absorbed and emitted. The grains evaporate if the grain temperature is higher than the condensation temperature. The formation of a Stroemgren sphere in the exploding envelope of a nova is discussed. For the formation of grains, it is necessary that temperature drops below the condensation temperature before the whole envelope is ionized. Hence dust grains do not grow if the grain temperature at a phase is higher than the condensation temperature. (Kako, I.)

The formation of stellar black holes

Science.gov (United States)

Mirabel, Félix

2017-08-01

It is believed that stellar black holes (BHs) can be formed in two different ways: Either a massive star collapses directly into a BH without a supernova (SN) explosion, or an explosion occurs in a proto-neutron star, but the energy is too low to completely unbind the stellar envelope, and a large fraction of it falls back onto the short-lived neutron star (NS), leading to the delayed formation of a BH. Theoretical models set progenitor masses for BH formation by implosion, namely, by complete or almost complete collapse, but observational evidences have been elusive. Here are reviewed the observational insights on BHs formed by implosion without large natal kicks from: (1) the kinematics in three dimensions of space of five Galactic BH X-ray binaries (BH-XRBs), (2) the diversity of optical and infrared observations of massive stars that collapse in the dark, with no luminous SN explosions, possibly leading to the formation of BHs, and (3) the sources of gravitational waves (GWs) produced by mergers of stellar BHs so far detected with LIGO. Multiple indications of BH formation without ejection of a significant amount of matter and with no natal kicks obtained from these different areas of observational astrophysics, and the recent observational confirmation of the expected dependence of BH formation on metallicity and redshift, are qualitatively consistent with the high merger rates of binary black holes (BBHs) inferred from the first detections with LIGO.

Endogenous leukotriene formation during anaphylactic shock

International Nuclear Information System (INIS)

Keppler, A.; Oerning, L.; Bernstroem, K.; Hammarstroem, S.

1987-01-01

Leukotriene (LT)C 4 is a biologically active substance, presumed to play major roles as a mediator of allergic and anaphylactic reactions. It is formed e.g. by basophilic and eosinophilic leukocytes, monocytes, macrophages, and mast cells. In cells having IgE receptors, bridging of these by divalent anti-IgE-receptor antibodies or by interaction between receptor-bound IgE and anti-IgE will induce LTC 4 formation. Leukotriene formation has also been demonstrated in other in vitro models of immediate hypersensivity. The biological actions of LTC 4 , comprise induction of airway obstruction, constriction of coronary arteries, hypotension, and plasma extravasation. Leukotriene formation in vivo may mediate anaphylactic shock symptoms and cause the death of an animal. In order to prove the presumed mediator role of this substance in anaphylactic reactions, it is necessary to demonstrate its endogenous formation during shock. Studies on the metabolism of LTC 4 have revealed rapid catabolism by various transformations of the peptide substituent. Recently, three metabolites were demonstrated to be excreted as end-products in man (LTE 4 ,) and the rat (N-acetyl LTE 4 and N-acetyl 11-trans LTE 4 ). By monitoring biliary N-acetyl LTE 4 levels, endogenous leukotriene formation in the rat was demonstrated in vivo after tissue trauma and endotoxin shock. We now wish to report evidence for endogenous leukotriene C 4 production during anaphylactic shock in guinea pigs. 37 refs. (author)

Pattern formations and oscillatory phenomena

CERN Document Server

Kinoshita, Shuichi

2013-01-01

Patterns and their formations appear throughout nature, and are studied to analyze different problems in science and make predictions across a wide range of disciplines including biology, physics, mathematics, chemistry, material science, and nanoscience. With the emergence of nanoscience and the ability for researchers and scientists to study living systems at the biological level, pattern formation research has become even more essential. This book is an accessible first of its kind guide for scientists, researchers, engineers, and students who require a general introduction to thi

The formation of ice sails

Science.gov (United States)

Fowler, A. C.; Mayer, C.

2017-11-01

Debris-covered glaciers are prone to the formation of a number of supraglacial geomorphological features, and generally speaking, their upper surfaces are far from level surfaces. Some of these features are due to radiation screening or enhancing properties of the debris cover, but theoretical explanations of the consequent surface forms are in their infancy. In this paper we consider a theoretical model for the formation of "ice sails", which are regularly spaced bare ice features which are found on debris-covered glaciers in the Karakoram.

Nitrate formation during ozonation as a surrogate parameter for abatement of micropollutants and the N-nitrosodimethylamine (NDMA) formation potential.

Science.gov (United States)

Song, Yang; Breider, Florian; Ma, Jun; von Gunten, Urs

2017-10-01

In this study, nitrate formation from ammonium and/or dissolved organic nitrogen (DON) was investigated as a novel surrogate parameter to evaluate the abatement of micropollutants during ozonation of synthetic waters containing natural organic matter (NOM) isolates, a natural water and secondary wastewater effluents. Nitrate formation during ozonation was compared to the changes in UV absorbance at 254 nm (UVA 254 ) including the effect of pH. For low specific ozone doses UVA 254 was abated more efficiently than nitrate was formed. This is due to a relatively slow rate-limiting step for nitrate formation from the reaction between ozone and a proposed nitrogen-containing intermediate. This reaction cannot compete with the fast reactions between ozone and UV-absorbing moieties (e.g., activated aromatic compounds). To further test the kinetics of nitrate formation, two possible intermediates formed during ozonation of DON were tested. At pH 7, nitrate was formed during ozonation of acetone oxime and methyl nitroacetate with second-order rate constants of 256.7 ± 4.7 M -1  s -1 and 149.5 ± 5.8 M -1  s -1 , respectively. The abatement of the selected micropollutants (i.e., 17α-ethinylestradiol (EE2), carbamazepine (CBZ), bezafibrate (BZF), ibuprofen (IBU), and p-chlorobenzoic acid (pCBA)) was investigated for specific ozone doses ≤1.53 mgO 3 /mgDOC and its efficiency depended strongly on the reactivity of the selected compounds with ozone. The relative abatement of micropollutants (i.e., EE2 and CBZ) with high ozone reactivity showed linear relationships with nitrate formation. The abatement of micropollutants with intermediate-low ozone reactivity (BZF, IBU, and pCBA) followed one- and two-phase behaviors relative to nitrate formation during ozonation of water samples containing high and low concentrations of nitrate-forming DON, respectively. During ozonation of a wastewater sample, the N-nitrosodimethylamine formation potential (NDMA-FP) during

THE PSYCHOLOGICAL PECULIARITIES OF THE INFORMATION-COMMUNICATION COMPETENCE FORMATION

Directory of Open Access Journals (Sweden)

Pyannikov Mikhail Mikhailovich

2013-01-01

Full Text Available Informatization of society has significantly changed the paradigm of education, posing the new problems to the scientists. One of such problems is the formation of new conscience – conscience, whose inalienable part is the information culture. The information-communication competence is the basis for the formation of such conscience. In this connection the aim of study is the analysis of psychological peculiarities of the formation of information-communication competence and determination of the role of this personality new formation in conscience of a modern human. The characteristic features of psychological new formations, the stages of cultural development and the role of cultural level of society in the formation of world outlook of a child are studied in this work. In the result of study there was found out the basis of psychic development. The sphere of results application includes the conclusions received in the result of study, which can be used by scholars, who deal with the problem of psychic development of a child. In practice the data of study help to understand better the stages of skill formation and the role of elementary actions in the formation of complex behavioral system.

Relative dynamics and motion control of nanosatellite formation flying

Science.gov (United States)

Pimnoo, Ammarin; Hiraki, Koju

2016-04-01

Orbit selection is a necessary factor in nanosatellite formation mission design/meanwhile, to keep the formation, it is necessary to consume fuel. Therefore, the best orbit design for nanosatellite formation flying should be one that requires the minimum fuel consumption. The purpose of this paper is to analyse orbit selection with respect to the minimum fuel consumption, to provide a convenient way to estimate the fuel consumption for keeping nanosatellite formation flying and to present a simplified method of formation control. The formation structure is disturbed by J2 gravitational perturbation and other perturbing accelerations such as atmospheric drag. First, Gauss' Variation Equations (GVE) are used to estimate the essential ΔV due to the J2 perturbation and atmospheric drag. The essential ΔV presents information on which orbit is good with respect to the minimum fuel consumption. Then, the linear equations which account for J2 gravitational perturbation of Schweighart-Sedwick are presented and used to estimate the fuel consumption to maintain the formation structure. Finally, the relative dynamics motion is presented as well as a simplified motion control of formation structure by using GVE.

Flexible Structure Control Scheme of a UAVs Formation to Improve the Formation Stability During Maneuvers

Directory of Open Access Journals (Sweden)

Kownacki Cezary

2017-09-01

Full Text Available One of the issues related to formation flights, which requires to be still discussed, is the stability of formation flight in turns, where the aerodynamic conditions can be substantially different for outer vehicles due to varying bank angles. Therefore, this paper proposes a decentralized control algorithm based on a leader as the reference point for followers, i.e. other UAVs and two flocking behaviors responsible for local position control, i.e. cohesion and repulsion. But opposite to other research in this area, the structure of the formation becomes flexible (structure is being reshaped and bent according to actual turn radius of the leader. During turns the structure is bent basing on concentred circles with different radiuses corresponding to relative locations of vehicles in the structure. Simultaneously, UAVs' air-speeds must be modified according to the length of turn radius to achieve the stability of the structure. The effectiveness of the algorithm is verified by the results of simulated flights of five UAVs.

ALPINE MAGMATIC-METALLOGENIC FORMATIONS OF THE NORTHWESTERN AND CENTRAL DINARIDES

Directory of Open Access Journals (Sweden)

Jakob Pamić

1997-12-01

Full Text Available In the paper are presented basic geological, petrologieca1, geochemi-cal and mineral deposit data for five main magmatic-metallogenic formations of the northwestern and central Dinarides: (lThe Permo Triassic rifting related andesite-diorite formations; (2 The Jurassic-Lower Cretaceous accretionary (ophiolite formations; (3 The Upper Cretaceous-Paleogene subduction related basalt-rhyohite formations; (4 The Paleogene collisional granite formations, and (5 The Oligo-cene-Neogene postsubduction andesite formations. All these magmatic-metallogenic formations originated in different geotectonic settings during the Alpine evolution of the Dinaridic parts of thc Tethys and the postorogenic evolution of the Paratethys and the Pannonian Basin, respectively.

Thermodynamics and kinetics of vesicles formation processes.

Science.gov (United States)

Guida, Vincenzo

2010-12-15

Vesicles are hollow aggregates, composed of bilayers of amphiphilic molecules, dispersed into and filled with a liquid solvent. These aggregates can be formed either as equilibrium or as out of equilibrium meta-stable structures and they exhibit a rich variety of different morphologies. The surprising richness of structures, the vast range of industrial applications and the presence of vesicles in a number of biological systems have attracted the interest of numerous researchers and scientists. In this article, we review both the thermodynamics and the kinetics aspects of the phenomena of formation of vesicles. We start presenting the thermodynamics of bilayer membranes formation and deformation, with the aim of deriving the conditions for the existence of equilibrium vesicles. Specifically, we use the results from continuum thermodynamics to discuss the possibility of formation of stable equilibrium vesicles, from both mixed amphiphiles and single component systems. We also link the bilayer membrane properties to the molecular structure of the starting amphiphiles. In the second part of this article, we focus on the dynamics and kinetics of vesiculation. We review the process of vesicles formation both from planar lamellar phase under shear and from isotropic micelles. In order to clarify the physical mechanisms of vesicles formation, we continuously draw a parallel between emulsification and vesiculation processes. Specifically, we compare the experimental results, the driving forces and the relative scaling laws identified for the two processes. Describing the dynamics of vesicles formation, we also discuss why non equilibrium vesicles can be formed by kinetics control and why they are meta-stable. Understanding how to control the properties, the stability and the formation process of vesicles is of fundamental importance for a vast number of industrial applications. Copyright © 2009. Published by Elsevier B.V.

Object formation and subject formation: The innovation campus in the Netherlands

NARCIS (Netherlands)

Kooij, H.J.

2015-01-01

A central question within planning theory is how changes between the relations of ‘grand institutions’ such as state, market and education influence the formation of objects ‘on the ground’. Drawing upon Foucault’s work, this article contributes to the understanding of these relations and argues

The early ISM and galaxy formation

Science.gov (United States)

White, Simon D. M.

1990-01-01

Current ideas about galaxy formation are reviewed, with particular attention to when and how it occurred, and what it might have looked like. It is argued that galaxy formation is more recent than originally predicted. Suggestions are presented as to how current observations of distant objects may be interpreted within the cold dark matter theory for the origin of structure.

Atmospheric particle formation in spatially and temporally varying conditions

Energy Technology Data Exchange (ETDEWEB)

Lauros, J.

2011-07-01

Atmospheric particles affect the radiation balance of the Earth and thus the climate. New particle formation from nucleation has been observed in diverse atmospheric conditions but the actual formation path is still unknown. The prevailing conditions can be exploited to evaluate proposed formation mechanisms. This study aims to improve our understanding of new particle formation from the view of atmospheric conditions. The role of atmospheric conditions on particle formation was studied by atmospheric measurements, theoretical model simulations and simulations based on observations. Two separate column models were further developed for aerosol and chemical simulations. Model simulations allowed us to expand the study from local conditions to varying conditions in the atmospheric boundary layer, while the long-term measurements described especially characteristic mean conditions associated with new particle formation. The observations show statistically significant difference in meteorological and back-ground aerosol conditions between observed event and non-event days. New particle formation above boreal forest is associated with strong convective activity, low humidity and low condensation sink. The probability of a particle formation event is predicted by an equation formulated for upper boundary layer conditions. The model simulations call into question if kinetic sulphuric acid induced nucleation is the primary particle formation mechanism in the presence of organic vapours. Simultaneously the simulations show that ignoring spatial and temporal variation in new particle formation studies may lead to faulty conclusions. On the other hand, the theoretical simulations indicate that short-scale variations in temperature and humidity unlikely have a significant effect on mean binary water sulphuric acid nucleation rate. The study emphasizes the significance of mixing and fluxes in particle formation studies, especially in the atmospheric boundary layer. The further

Negative ion formation processes: A general review

International Nuclear Information System (INIS)

Alton, G.D.

1990-01-01

The principal negative ion formation processes will be briefly reviewed. Primary emphasis will be placed on the more efficient and universal processes of charge transfer and secondary ion formation through non-thermodynamic surface ionization. 86 refs., 20 figs

Protostar formation in the early universe.

Science.gov (United States)

Yoshida, Naoki; Omukai, Kazuyuki; Hernquist, Lars

2008-08-01

The nature of the first generation of stars in the universe remains largely unknown. Observations imply the existence of massive primordial stars early in the history of the universe, and the standard theory for the growth of cosmic structure predicts that structures grow hierarchically through gravitational instability. We have developed an ab initio computer simulation of the formation of primordial stars that follows the relevant atomic and molecular processes in a primordial gas in an expanding universe. The results show that primeval density fluctuations left over from the Big Bang can drive the formation of a tiny protostar with a mass 1% that of the Sun. The protostar is a seed for the subsequent formation of a massive primordial star.

Microwave based method of monitoring crack formation

International Nuclear Information System (INIS)

Aman, Sergej; Aman, Alexander; Majcherek, Soeren; Hirsch, Soeren; Schmidt, Bertram

2014-01-01

The formation of cracks in glass particles was monitored by application of linearly polarized microwaves. The breakage behavior of glass spheres coated with a thin gold layer of about 50 nm, i.e. a thickness that is lower than the microwave penetration depth, was tested. In this way the investigation of fracture behavior of electronic circuits was simulated. A shielding current was induced in the gold layer by the application of microwaves. During the crack formation the distribution of this current changed abruptly and a scattered microwave signal appeared at the frequency of the incident microwaves. The time behavior of the scattered signal reflects the microscopic processes occurring during the fracture of the specimen. The duration of the increasing signal corresponds to the crack formation time in the tested specimen. This time was estimated as particle size divided by crack development speed in glass. An intense emission of electrons occurs during the formation of cracks. Due to this, coherent Thomson scattering of microwaves by emitted electrons becomes significant with a delay of a few microseconds after the initial phase of crack formation. In this time the intensity of the microwave signal increases. (paper)

Galaxy formation: internal mechanisms and cosmological processes

International Nuclear Information System (INIS)

Martig, Marie

2010-01-01

This thesis is devoted to galaxy formation and evolution in a cosmological context. Cosmological simulations have unveiled two main modes of galaxy growth: hierarchical growth by mergers and accretion of cold gas from cosmic filaments. However, these simulations rarely take into account small scale mechanisms, that govern internal evolution and that are a key ingredient to understand galaxy formation and evolution. Thanks to a new simulation technique that I have developed, I first studied the colors of galaxies, and in particular the reddening of elliptical galaxies. I showed that the gas disk in an elliptical galaxy could be stabilized against star formation because of the galaxy's stellar component being within a spheroid instead of a disk. This mechanism can explain the red colors of some elliptical galaxies that contain a gas disk. I also studied the formation of spiral galaxies: most cosmological simulations cannot explain the formation of Milky Way-like galaxies, i.e. with a large disk and a small bulge. I showed that this issue could be partly solved by taking into account in the simulations the mass loss from evolved stars through stellar winds, planetary nebulae and supernovae explosions. (author) [fr

Star-formation history of very young clusters

International Nuclear Information System (INIS)

Stahler, S.W.

1985-01-01

The popular idea that star formation has proceeded sequentially from lowest to highest mass members in open clusters is examined critically. For extremely young clusters, such as NGC 2264 and NGC 6530, this sequential hypothesis is a consequence of the assignment of pre-main-sequence contraction ages to all member stars. However, such ages yield a formation history which is implausible from a physical point of view, since the critical time for the onset of formation at any stellar mass is equal to the pre-main-sequence contraction time for that mass. Moreover, these ages are in conflict with the strong observational evidence that a substantial fraction of cluster members have already reached the main sequence. After reconsideration of the probable main-sequence members, the stellar ages in NGC 2264 and NGC 6530 are consistent with a variety of formation histories, and, in particular, with the view that all stellar masses form in approximately the same interval of time within a given cluster, i.e., that there is no mass-age correlation. A notion closely related to the sequential hypothesis, that the total star-formation rate increases exponentially with time, is subject to the same criticism

The formation of planets by disc fragmentation

Directory of Open Access Journals (Sweden)

Stamatellos Dimitris

2013-04-01

Full Text Available I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar discs may fragment, if they are massive enough and can cool fast enough, but most of the objects that form by fragmentation are brown dwarfs. It may be possible that planets also form, if the mass growth of a proto-fragment is stopped (e.g. if this fragment is ejected from the disc, or suppressed and even reversed (e.g by tidal stripping. I will discuss if it is possible to distinguish whether a planet has formed by disc fragmentation or core accretion, and mention of a few examples of observed exoplanets that are suggestive of formation by disc fragmentation.

Promoting proximal formative assessment with relational discourse

Science.gov (United States)

Scherr, Rachel E.; Close, Hunter G.; McKagan, Sarah B.

2012-02-01

The practice of proximal formative assessment - the continual, responsive attention to students' developing understanding as it is expressed in real time - depends on students' sharing their ideas with instructors and on teachers' attending to them. Rogerian psychology presents an account of the conditions under which proximal formative assessment may be promoted or inhibited: (1) Normal classroom conditions, characterized by evaluation and attention to learning targets, may present threats to students' sense of their own competence and value, causing them to conceal their ideas and reducing the potential for proximal formative assessment. (2) In contrast, discourse patterns characterized by positive anticipation and attention to learner ideas increase the potential for proximal formative assessment and promote self-directed learning. We present an analysis methodology based on these principles and demonstrate its utility for understanding episodes of university physics instruction.

Inflow of atomic gas fuelling star formation

DEFF Research Database (Denmark)

Michałowski, M. J.; Gentile, G.; Hjorth, Jeppe

2016-01-01

Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation in these ga......Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation...... in these galaxies may be fuelled by recent inflow of metal-poor atomic gas. While this process is debated, it can happen in low-metallicity gas near the onset of star formation because gas cooling (necessary for star formation) is faster than the Hi-to-H2 conversion....

Systematization of experiences in the professor formation to integrate the university and the family to the professional formation.

Directory of Open Access Journals (Sweden)

Geycell Emma Guevara Fernández

2012-04-01

Full Text Available The current work presents a systematization of experiences carried out at the University José Martí Pérez of Sancti Spíritus as a modality of participative action research which permitted, from the articulation of theory and practice, to organize the knowledge about family-university relationship and its influence in the professional formation. As a starting point, different diagnostic techniques were applied such as: document analysis, participating observation, auto assessing scales, discussion groups, interviews, survey and the methodological triangulation data which led to the determination of shortages and potentialities that the staff had as to formation to face it. By means of a shared process, the implied actors agreed the execution of actions which supplied the formative needs and led to grow up gradually towards the improvement of a continuing formation for the educative orientation carried out in higher education and where the development social situation of the young university professor demands as a fundamental category.

Distributed formation tracking using local coordinate systems

DEFF Research Database (Denmark)

Yang, Qingkai; Cao, Ming; Garcia de Marina, Hector

2018-01-01

This paper studies the formation tracking problem for multi-agent systems, for which a distributed estimator–controller scheme is designed relying only on the agents’ local coordinate systems such that the centroid of the controlled formation tracks a given trajectory. By introducing a gradient...... descent term into the estimator, the explicit knowledge of the bound of the agents’ speed is not necessary in contrast to existing works, and each agent is able to compute the centroid of the whole formation in finite time. Then, based on the centroid estimation, a distributed control algorithm...

Emissions and dioxins formation from waste incinerators

International Nuclear Information System (INIS)

Carbone, A.I.; Zagaroli, M.

1989-01-01

This paper describes current knowledge on dioxins formation and emission from waste incinerators. The pertinent Italian law and effects on man health are dealt with, too. The picture of existing municipal incinerators is presented concerning both the actual emission levels and the monitored levels in the environment. Sampling and analysis systems of these organic chlorinated micro-pollutants and current theories on precursors, formation mechanisms, and influence of different parameters are also described. The last section deals with some of the techniques that can be used to reduce dioxins formation and emission from municipal incinerators. (author)

Formation and filtration characteristics of solids generated in a high level liquid waste treatment process. Solids formation behavior from simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.; Kubota, M.

1997-01-01

The solids formation behavior in a simulated high level liquid waste (HLLW) was experimentally examined, when the simulated HLLW was treated in the ordinary way of actual HLLW treatment process. Solids formation conditions and mechanism were closely discussed. The solids formation during a concentration step can be explained by considering the formation of zirconium phosphate, phosphomolybdic acid and precipitation of strontium and barium nitrates and their solubilities. For the solids formation during the denitration step, at least four courses were observed; formation of an undissolved material by a chemical reaction with each other of solute elements (zirconium, molybdenum, tellurium) precipitation by reduction (platinum group metals) formation of hydroxide or carbonate compounds (chromium, neodymium, iron, nickel, strontium, barium) and a physical adsorption to stable solid such as zirconium molybdate (nickel, strontium, barium). (author)

Plasma formation in TBR

International Nuclear Information System (INIS)

Del Bosco, E.

1981-01-01

In this work are presented and discussed results of the formation and equilibrium of the plasma current in TBR, a small tokamak, designed and contructed at the Instituto de Fisica of Universidade de Sao Paulo. The measured breakdown curves for H 2 , A and He are compared with the predictions of a simple model with reasonable agreement. The influence of stray magnetic fields in the plasma formation is investigated and conditions are chosen to facilitate the breakdown. The time profile of loop voltage and plasma current for shots with plasma equilibrium are shown. A comparison is made between experimental results and analytical-numerical model for tokamaks discharges with ohmic heating. Reasonable agreement is obtained when Z, effective atomic number, is assumed as a parameter. (Author) [pt

Reconsidering Formative Measurement

Science.gov (United States)

Howell, Roy D.; Breivik, Einar; Wilcox, James B.

2007-01-01

The relationship between observable responses and the latent constructs they are purported to measure has received considerable attention recently, with particular focus on what has become known as formative measurement. This alternative to reflective measurement in the area of theory-testing research is examined in the context of the potential…

Cu(II) promotes amyloid pore formation

International Nuclear Information System (INIS)

Zhang, Hangyu; Rochet, Jean-Christophe; Stanciu, Lia A.

2015-01-01

The aggregation of α-synuclein is associated with dopamine neuron death in Parkinson's disease. There is controversy in the field over the question of which species of the aggregates, fibrils or protofibrils, are toxic. Moreover, compelling evidence suggested the exposure to heavy metals to be a risk of PD. Nevertheless, the mechanism of metal ions in promoting PD remains unclear. In this research, we investigated the structural basis of Cu(II) induced aggregation of α-synuclein. Using transmission electron microscopy experiments, Cu(II) was found to promote in vitro aggregation of α-synuclein by facilitating annular protofibril formation rather than fibril formation. Furthermore, neuroprotective baicalein disaggregated annular protofibrils accompanied by considerable decrease of β-sheet content. These results strongly support the hypothesis that annular protofibrils are the toxic species, rather than fibrils, thereby inspiring us to search novel therapeutic strategies for the suppression of the toxic annular protofibril formation. - Highlights: • Cu(II) promoted the annular protofibril formation of α-synuclein in vitro. • Cu(II) postponed the in vitro fibrillization of α-synuclein. • Neuroprotective baicalein disaggregated annular protofibrils

Cu(II) promotes amyloid pore formation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hangyu, E-mail: hangyuz@uw.edu [Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 (United States); Rochet, Jean-Christophe [Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907 (United States); Stanciu, Lia A. [Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, IN 47907 (United States)

2015-08-14

The aggregation of α-synuclein is associated with dopamine neuron death in Parkinson's disease. There is controversy in the field over the question of which species of the aggregates, fibrils or protofibrils, are toxic. Moreover, compelling evidence suggested the exposure to heavy metals to be a risk of PD. Nevertheless, the mechanism of metal ions in promoting PD remains unclear. In this research, we investigated the structural basis of Cu(II) induced aggregation of α-synuclein. Using transmission electron microscopy experiments, Cu(II) was found to promote in vitro aggregation of α-synuclein by facilitating annular protofibril formation rather than fibril formation. Furthermore, neuroprotective baicalein disaggregated annular protofibrils accompanied by considerable decrease of β-sheet content. These results strongly support the hypothesis that annular protofibrils are the toxic species, rather than fibrils, thereby inspiring us to search novel therapeutic strategies for the suppression of the toxic annular protofibril formation. - Highlights: • Cu(II) promoted the annular protofibril formation of α-synuclein in vitro. • Cu(II) postponed the in vitro fibrillization of α-synuclein. • Neuroprotective baicalein disaggregated annular protofibrils.

Transcriptional regulation of Drosophila gonad formation.

Science.gov (United States)

Tripathy, Ratna; Kunwar, Prabhat S; Sano, Hiroko; Renault, Andrew D

2014-08-15

The formation of the Drosophila embryonic gonad, involving the fusion of clusters of somatic gonadal precursor cells (SGPs) and their ensheathment of germ cells, provides a simple and genetically tractable model for the interplay between cells during organ formation. In a screen for mutants affecting gonad formation we identified a SGP cell autonomous role for Midline (Mid) and Longitudinals lacking (Lola). These transcriptional factors are required for multiple aspects of SGP behaviour including SGP cluster fusion, germ cell ensheathment and gonad compaction. The lola locus encodes more than 25 differentially spliced isoforms and we have identified an isoform specific requirement for lola in the gonad which is distinct from that in nervous system development. Mid and Lola work in parallel in gonad formation and surprisingly Mid overexpression in a lola background leads to additional SGPs at the expense of fat body cells. Our findings support the idea that although the transcription factors required by SGPs can ostensibly be assigned to those being required for either SGP specification or behaviour, they can also interact to impinge on both processes. Copyright © 2014 Elsevier Inc. All rights reserved.

TIME-VARYING DYNAMICAL STAR FORMATION RATE

Energy Technology Data Exchange (ETDEWEB)

Lee, Eve J.; Chang, Philip; Murray, Norman, E-mail: evelee@berkeley.edu [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, University of Toronto, Toronto, ON M5S 3H8 (Canada)

2015-02-10

We present numerical evidence of dynamic star formation in which the accreted stellar mass grows superlinearly with time, roughly as t {sup 2}. We perform simulations of star formation in self-gravitating hydrodynamic and magnetohydrodynamic turbulence that is continuously driven. By turning the self-gravity of the gas in the simulations on or off, we demonstrate that self-gravity is the dominant physical effect setting the mass accretion rate at early times before feedback effects take over, contrary to theories of turbulence-regulated star formation. We find that gravitational collapse steepens the density profile around stars, generating the power-law tail on what is otherwise a lognormal density probability distribution function. Furthermore, we find turbulent velocity profiles to flatten inside collapsing regions, altering the size-line width relation. This local flattening reflects enhancements of turbulent velocity on small scales, as verified by changes to the velocity power spectra. Our results indicate that gas self-gravity dynamically alters both density and velocity structures in clouds, giving rise to a time-varying star formation rate. We find that a substantial fraction of the gas that forms stars arrives via low-density flows, as opposed to accreting through high-density filaments.

Solution mining dawsonite from hydrocarbon containing formations with a chelating agent

Science.gov (United States)

Vinegar, Harold J [Bellaire, TX

2009-07-07

A method for treating an oil shale formation comprising dawsonite includes providing heat from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation. At least some dawsonite in the formation is decomposed with the provided heat. A chelating agent is provided to the formation to dissolve at least some dawsonite decomposition products. The dissolved dawsonite decomposition products are produced from the formation.

Evaluation of anomalies during nickel and titanium silicide formation using the effective heat of formation mode

CSIR Research Space (South Africa)

Pretorius, R

1993-11-01

Full Text Available , as well as the observed sequence of growth of different silicide phases, are not in agree- ment with thermodynamic considerations [26]. In the case of the nickel silicides Ni,Si is nearly always found to be the first... to determine how the oxygen content in the silicon affects phase formation. We also show how the anomalous behaviour of titanium and nickel silicide formation can be explained thermodynamically by using the ?effective heat...

Black-hole-regulated star formation in massive galaxies

Science.gov (United States)

Martín-Navarro, Ignacio; Brodie, Jean P.; Romanowsky, Aaron J.; Ruiz-Lara, Tomás; van de Ven, Glenn

2018-01-01

Supermassive black holes, with masses more than a million times that of the Sun, seem to inhabit the centres of all massive galaxies. Cosmologically motivated theories of galaxy formation require feedback from these supermassive black holes to regulate star formation. In the absence of such feedback, state-of-the-art numerical simulations fail to reproduce the number density and properties of massive galaxies in the local Universe. There is, however, no observational evidence of this strongly coupled coevolution between supermassive black holes and star formation, impeding our understanding of baryonic processes within galaxies. Here we report that the star formation histories of nearby massive galaxies, as measured from their integrated optical spectra, depend on the mass of the central supermassive black hole. Our results indicate that the black-hole mass scales with the gas cooling rate in the early Universe. The subsequent quenching of star formation takes place earlier and more efficiently in galaxies that host higher-mass central black holes. The observed relation between black-hole mass and star formation efficiency applies to all generations of stars formed throughout the life of a galaxy, revealing a continuous interplay between black-hole activity and baryon cooling.

Black-hole-regulated star formation in massive galaxies.

Science.gov (United States)

Martín-Navarro, Ignacio; Brodie, Jean P; Romanowsky, Aaron J; Ruiz-Lara, Tomás; van de Ven, Glenn

2018-01-18

Supermassive black holes, with masses more than a million times that of the Sun, seem to inhabit the centres of all massive galaxies. Cosmologically motivated theories of galaxy formation require feedback from these supermassive black holes to regulate star formation. In the absence of such feedback, state-of-the-art numerical simulations fail to reproduce the number density and properties of massive galaxies in the local Universe. There is, however, no observational evidence of this strongly coupled coevolution between supermassive black holes and star formation, impeding our understanding of baryonic processes within galaxies. Here we report that the star formation histories of nearby massive galaxies, as measured from their integrated optical spectra, depend on the mass of the central supermassive black hole. Our results indicate that the black-hole mass scales with the gas cooling rate in the early Universe. The subsequent quenching of star formation takes place earlier and more efficiently in galaxies that host higher-mass central black holes. The observed relation between black-hole mass and star formation efficiency applies to all generations of stars formed throughout the life of a galaxy, revealing a continuous interplay between black-hole activity and baryon cooling.

Cloud Optimized Image Format and Compression

Science.gov (United States)

Becker, P.; Plesea, L.; Maurer, T.

2015-04-01

Cloud based image storage and processing requires revaluation of formats and processing methods. For the true value of the massive volumes of earth observation data to be realized, the image data needs to be accessible from the cloud. Traditional file formats such as TIF and NITF were developed in the hay day of the desktop and assumed fast low latency file access. Other formats such as JPEG2000 provide for streaming protocols for pixel data, but still require a server to have file access. These concepts no longer truly hold in cloud based elastic storage and computation environments. This paper will provide details of a newly evolving image storage format (MRF) and compression that is optimized for cloud environments. Although the cost of storage continues to fall for large data volumes, there is still significant value in compression. For imagery data to be used in analysis and exploit the extended dynamic range of the new sensors, lossless or controlled lossy compression is of high value. Compression decreases the data volumes stored and reduces the data transferred, but the reduced data size must be balanced with the CPU required to decompress. The paper also outlines a new compression algorithm (LERC) for imagery and elevation data that optimizes this balance. Advantages of the compression include its simple to implement algorithm that enables it to be efficiently accessed using JavaScript. Combing this new cloud based image storage format and compression will help resolve some of the challenges of big image data on the internet.