Genesis Radiation Environment

NASA Technical Reports Server (NTRS)

Minow, Joseph I.; Altstatt, Richard L.; Skipworth, William C.

2007-01-01

The Genesis spacecraft launched on 8 August 2001 sampled solar wind environments at L1 from 2001 to 2004. After the Science Capsule door was opened, numerous foils and samples were exposed to the various solar wind environments during periods including slow solar wind from the streamer belts, fast solar wind flows from coronal holes, and coronal mass ejections. The Survey and Examination of Eroded Returned Surfaces (SEERS) program led by NASA's Space Environments and Effects program had initiated access for the space materials community to the remaining Science Capsule hardware after the science samples had been removed for evaluation of materials exposure to the space environment. This presentation will describe the process used to generate a reference radiation Genesis Radiation Environment developed for the SEERS program for use by the materials science community in their analyses of the Genesis hardware.

The Mineralogy and Petrology of Anomalous Eucrite Emmaville

NASA Technical Reports Server (NTRS)

Barrett, T. J.; Mittlefehldt, D. W.; Ross, D. K.; Greenwood, R. C.; Anand, M.; Franchi, I. A.; Grady, M. M.; Charlier, B. L. A.

2015-01-01

It has long been known that certain basaltic achondrites share similarities with eucrites. These eucrite-like achondrites have distinct isotopic compositions and petrologic characteristics indicative of formation on a separate parent body from the howardite-eucrite-diogenite (HED) clan (e.g., Ibitira, Northwest Africa (NWA) 011). Others show smaller isotopic variations but are otherwise petrologically and compositionally indistinguishable from basaltic eucrites (e.g., Pasamonte, Pecora Escarpment (PCA) 91007). The Emmaville eucrite has a delta O-17 value of -0.137 plus or minus 0.024 per mille (1 sigma), which is substantially different from the eucrite mean of -0.246 plus or minus 0.014 per mille (2 sigma), but similar to those of A-881394 and Bunburra Rockhole (BR). Currently little data exist for Emmaville in terms of petrology or bulk composition. Studying anomalous eucrites allows us to more completely understand the numbers of asteroids represented by eucrite- like basalts and thus constrain the heterogeneity of the HED suite. In this study, we present our preliminary petrological and mineral composition results for Emmaville.

Anatomic documentation of the G-spot complex role in the genesis of anterior vaginal wall ballooning.

PubMed

Ostrzenski, Adam

2014-09-01

To expand previous G-spot anatomical and histological investigations; to examine the G-spot complex anatomic role in the anterior vaginal wall ballooning bio-mechanisms; and to determine, which division of autonomic nervous system (sympathetic or parasympathetic) dominates at the time of female sudden death. A prospective-descriptive case series anatomical study on eleven consecutive fresh humane female cadavers was conducted. Anterior vaginal wall stratum-by-stratum macro-dissections were executed in axial, coronal and sagittal plains. Upon G-spot extirpations, micro-dissections were performed. The G-spot tissues were stained with hematoxilin and eosin for histological examinations to authenticate the G-spot anatomical and histological characteristic features. The G-spot complex was identified and present in all subjects on either the distal vaginal left (more often) or on the right side from the lateral margin of the urethra; the G-spot anatomical and microscopic characteristic features have been authenticated; the G-spot complex expansion elevated anterior vaginal walls in each subject; the autonomic parasympathetic nervous system was the dominant division at the time of female subject sudden death. This study advances our anatomical and histological understanding of the G-spot complex and its role in the genesis of anterior vaginal ballooning bio-mechanisms. The G-spot complex is under parasympathetic nervous system domination at the time of female sudden death. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Proceedings of the twentieth annual meeting of the society for organic petrology

USGS Publications Warehouse

Bragg, Linda J.; Lentz, Erika E.; Warwick, Peter D.; Finkelman, Robert B.; Trippi, Michael H.; Karlsen, Alex W.

2004-01-01

The Society for Organic Petrology (TSOP; pronounced "Tee'-sop") was established in 1984 to consolidate and foster the organizational activities of scientists and engineers involved with coal petrology, kerogen petrology, organic geochemistry, and related disciplines. The following report, "Proceedings of the Twentieth Annual Meeting of The Society for Organic Petrology" (ISSN 1060-7250), features technical talks, poster presentations, business meetings, short courses, and field trips from the Fall 2003 annual meeting held in Washington, D.C.

Assessment of Petrological Microscopes.

ERIC Educational Resources Information Center

Mathison, Charter Innes

1990-01-01

Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

Petrologically-based Electrical Profiles vs. Geophysical Observations through the Upper Mantle (Invited)

NASA Astrophysics Data System (ADS)

Gaillard, F.; Massuyeau, M.; Sifre, D.; Tarits, P.

2013-12-01

Mineralogical transformations in the up-welling mantle play a critical role on the dynamics of mass and heat transfers at mid-ocean-ridgeS. The melting event producing ridge basalts occur at 60 km depth below the ridge axis, but because of small amounts of H2O and CO2 in the source region of MOR-basalts, incipient melting can initiate at much greater depth. Such incipient melts concentrate incompatible elements, and are particularly rich in volatile species. These juices evolve from carbonatites, carbonated basalts, to CO2-H2O-rich basalts as recently exposed by petrological surveys; the passage from carbonate to silicate melts is a complex pathway that is strongly non-linear. This picture has recently been complicated further by studies showing that oxygen increasingly partitions into garnet as pressure increases; this implies that incipient melting may be prevented at depth exceeding 200 km because not enough oxygen is available in the system to stabilize carbonate melts. The aim of this work is twofold: - We modelled the complex pathway of mantle melting in presence of C-O-H volatiles by adjusting the thermodynamic properties of mixing in the multi-component C-O-H-melt system. This allows us to calculate the change in melt composition vs. depth following any sortS of adiabat. - We modelled the continuous change in electrical properties from carbonatites, carbonated basalts, to CO2-H2O-rich basalts. We then successfully converted this petrological evolution along a ridge adiabat into electrical conductivity vs. depth signal. The discussion that follows is about comparison of this petrologically-based conductivity profile with the recent profiles obtained by inversion of the long-period electromagnetic signals from the East-Pacific-Rise. These geophysically-based profiles reveal the electrical conductivity structure down to 400 km depth and they show some intriguing highly conductive sections. We will discuss heterogeneity in electrical conductivity of the upper

A Digital Approach to Learning Petrology

NASA Astrophysics Data System (ADS)

Reid, M. R.

2011-12-01

In the undergraduate igneous and metamorphic petrology course at Northern Arizona University, we are employing petrographic microscopes equipped with relatively inexpensive ( $200) digital cameras that are linked to pen-tablet computers. The camera-tablet systems can assist student learning in a variety of ways. Images provided by the tablet computers can be used for helping students filter the visually complex specimens they examine. Instructors and students can simultaneously view the same petrographic features captured by the cameras and exchange information about them by pointing to salient features using the tablet pen. These images can become part of a virtual mineral/rock/texture portfolio tailored to individual student's needs. Captured digital illustrations can be annotated with digital ink or computer graphics tools; this activity emulates essential features of more traditional line drawings (visualizing an appropriate feature and selecting a representative image of it, internalizing the feature through studying and annotating it) while minimizing the frustration that many students feel about drawing. In these ways, we aim to help a student progress more efficiently from novice to expert. A number of our petrology laboratory exercises involve use of the camera-tablet systems for collaborative learning. Observational responsibilities are distributed among individual members of teams in order to increase interdependence and accountability, and to encourage efficiency. Annotated digital images are used to share students' findings and arrive at an understanding of an entire rock suite. This interdependence increases the individual's sense of responsibility for their work, and reporting out encourages students to practice use of technical vocabulary and to defend their observations. Pre- and post-course student interest in the camera-tablet systems has been assessed. In a post-course survey, the majority of students reported that, if available, they would use

Mineralogy, petrology and chemistry of ANT-suite rocks from the lunar highlands

NASA Technical Reports Server (NTRS)

Prinz, M.; Keil, K.

1977-01-01

Anorthositic-noritic-troctolitic (ANT) rocks are the oldest and most abundant rocks of the lunar surface, and comprise about 90% of the suite of the lunar highlands. Consideration is given to the mineralogy, petrology, bulk chemistry, and origin of ANT-suite rocks. Problems associated in classifying and labeling lunar highland rocks because of textural complexities occurring from impact modifications are discussed. The mineralogy of ANT-suite rocks, dominated by plagioclase, olivine and pyrozene, and containing various minor minerals, is outlined. The petrology of ANT-suite rocks is reviewed along with the major element bulk composition of these rocks, noting that they are extremely depleted in K2O and P2O5. Various models describing the origin of ANT-suite rocks are summarized, and it is suggested that this origin involves a parental liquid of high-alumina basalt with low Fe/Fe+Mg.

Petrology and genesis of natrocarbonatite

NASA Astrophysics Data System (ADS)

Peterson, Tony D.

1990-03-01

Microprobe analyses of phenocrysts and groundmass, and crystal-size distributions of phenocrysts of pahoehoe natrocarbonatite lavas of the 1963 eruption of Oldoinyo Lengai have been determined. Nyerereite phenocrysts are homogeneous, with average composition Nc41Kc9Cc50 (neglecting F, Cl, P2O5, and SO3) where Nc=Na2CO3, Kc=K2CO3, and Cc= (Ca,Sr)CO3. Gregoryite phenocrysts have turbid, pale brown, oscillatorily zoned cores (average composition Nc77Kc5Cc18) with 0 30% oriented inclusions of exsolved nyerereite. Overgrowths on gregoryites (30 μm wide) are relatively sodic (Nc81Kc4Cc15) and are free of inclusions. Cores and rims are rich in SO3 (4%) and P2O5 (2%). Blebs of pyrite-alabandite mixtures (≤100 μm) occur in the groundmass. The groundmass has the simplified composition Nc65Kc15Cc20, less calcic than the composition of the 1-kbar nyerereite+gregoryite +liquid cotectic in the ternary system Nc-Kc-Cc. Groundmass quench growth of alkali halides + carbonate was followed by slower growth of coarse-grained and irregular gregoryite +KCl+BaCO3. Crystal size distributions of gregoryite and nyerereite in one sample are linear, implying little loss or gain of phenocrysts by crystal settling. Average Gτ is 0.15 mm, compared to Gτ=0.03 mm for combeite phenocrysts from consanguineous nephelinite. Assuming an equal residence time (τ) for both lavas, the apparent crystal growth rate ( G) in carbonate melt is 5 times greater than in peralkaline undersaturated silicate melt. Data from experiments with natrocarbonatite and related synthetic systems indicate that Na-K-Ca carbonatite magmas which crystallize calcite cannot fractionate to nyerereite+gregoryite +liquid assemblages. Natrocarbonatites plot in the liquidus field of nyerereite, and minor fractionation of nyerereite to produce the erupted lavas is indicated. The term natrocarbonatite has been inappropriately applied to other eruptive rocks with calcite phenocrysts, and the only known occurrence of gregoryite-bearing natrocarbonatite is Oldoinyo Lengai. Natrocarbonatite probably originates by liquid immiscibility from strongly peralkaline nephelinites, which have also been erupted at Oldoinyo Lengai.

Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

NASA Astrophysics Data System (ADS)

Richards, Mark; Ridley, Victoria

2010-05-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marqueses, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better

Principles of Metamorphic Petrology

NASA Astrophysics Data System (ADS)

Williams, Michael L.

2009-05-01

The field of metamorphic petrology has seen spectacular advances in the past decade, including new X-ray mapping techniques for characterizing metamorphic rocks and minerals, new internally consistent thermobarometers, new software for constructing and viewing phase diagrams, new methods to date metamorphic processes, and perhaps most significant, revised petrologic databases and the ability to calculate accurate phase diagrams and pseudosections. These tools and techniques provide new power and resolution for constraining pressure-temperature (P-T) histories and tectonic events. Two books have been fundamental for empowering petrologists and structural geologists during the past decade. Frank Spear's Metamorphic Phase Equilibria and Pressure-Temperature-Time Paths, published in 1993, builds on his seminal papers to provide a quantitative framework for P-T path analysis. Spear's book lays the foundation for modern quantitative metamorphic analysis. Cees Passchier and Rudolph Trouw's Microtectonics, published in 2005, with its superb photos and figures, provides the tools and the theory for interpreting deformation textures and inferring deformation processes.

Genesis Failure Investigation Report

NASA Technical Reports Server (NTRS)

Klein, John

2004-01-01

The-Genesis mission to collect solar-wind samples and return them to Earth for detailed analysis proceeded successfully for 3.5 years. During reentry on September 8, 2004, a failure in the entry, descent and landing sequence resulted in a crash landing of the Genesis sample return capsule. This document describes the findings of the avionics sub-team that supported the accident investigation of the JPL Failure Review Board.

Petrology of the Northern Anabar alkaline-ultramafic rocks (the Siberian Craton, Russia) and the role of metasomatized lithospheric mantle in their genesis

NASA Astrophysics Data System (ADS)

Kargin, Alexey; Golubeva, Yulia; Demonterova, Elena

2017-04-01

produced several carbonatite pipes and dykes. Their geochemical composition indicates the predominance of the carbonate component in the source region and a decrease of the thickness of the lithospheric mantle. This study was supported by Russian Science Foundation №16-17-10068. Tappe S., Foley S.F., Jenner G.A. et al. 2006. Genesis of Ultramafic Lamprophyres and Carbonatites at Aillik Bay, Labrador: a Consequence of Incipient Lithospheric Thinning beneath the North Atlantic Craton // J. Petrology. V. 47 (7). P. 1261-1315. Sun J., Liu C.Z., Tappe S. et al. 2014. Repeated kimberlite magmatism beneath Yakutia and its relationship to Siberian flood volcanism: Insights from in situ U-Pb and Sr-Nd perovskite isotope analysis // Earth Planet. Sci. Lett. V. 404. P. 283-295. Zaytsev A.I., Smelov A.P., 2010. Isotope Geochronology of Kimberlite Formation Rocks from Yakutian Province // Publication of the Institute of Diamonds Geology, Siberian branch of the Russian Academy of Sciences, Yakutsk (107 pp. (in Russian)).

Genesis Field Recovery

NASA Technical Reports Server (NTRS)

McNamara, K. M.

2005-01-01

The Genesis mission returned to Earth on September 8, 2004 after a nearly flawless three-year mission to collect solar matter. The intent was to deploy a drogue chute and parafoil high over the Utah desert and to catch the fragile payload capsule in mid-air by helicopter. The capsule would then be opened in a clean-room constructed for that purpose at UTTR, and a nitrogen purge was to be installed before transporting the science canister to JSC. Unfortunately, both chutes failed to deploy, causing the capsule to fall to the desert floor at a speed of nearly 200 MPH. Still, Genesis represents a milestone in the US space program, comprising the first sample return since the Apollo Missions as well as the first return of materials exposed to the space environment outside of low Earth orbit and beyond the Earth s magnetosphere for an extended period. We have no other comparable materials in all of our collections on Earth. The goal of the Genesis Mission was to collect a representative sample of the composition of the solar wind and thus, the solar nebula from which our solar system originated. This was done by allowing the naturally accelerated species to implant shallowly in the surfaces of ultra-pure, ultra-clean collector materials. These collectors included single crystal silicon (FZ and CZ), sapphire, silicon carbide; those materials coated with aluminum, silicon, diamond like carbon, and gold; and isotopically enriched polycrystalline diamond and amorphous carbon. The majority of these materials were distributed on five collector arrays. Three of the materials were housed in an electrostatic concentrator designed to increase the flux of low-mass ions. There was also a two-inch diameter bulk metallic glass collector and a gold foil, polished aluminum, and molybdenum coated platinum foil collector. An excellent review of the Genesis collector materials is offered in reference [1].

Modulation of Tropical Cyclone Genesis by Boreal Summer Intraseasonal Oscillation: An Anomalous Dynamic Genesis Potential Index

NASA Astrophysics Data System (ADS)

Moon, J.; Wang, B.

2016-12-01

The large scale circulation anomalies associated with boreal summer intraseasonal oscillation (BSISO) strongly controls the genesis of tropical cyclone in a global perspective. The present study attempts to reveal factors by which BSISO modulation of tropical cyclone genesis (TCG) using two genesis potential indices (GPI): Dynamic GPI (DGPI) and Emanuel and Nolan's GPI (ENGPI). The ENGPI contains two dynamic (the vertical wind shear and absolute vorticity at 850 hPa) and two thermodynamic factors (relative humidity at 600 hPa and maximum potential intensity), while DPGI replaced the two thermodynamic factors by two additional dynamic factors (500 hPa vertical velocity and meridional shear of zonal winds). The major basins of tropical cyclone genesis during May to October from 1979 to 2014 are divided into North Indian Ocean (NIO), Western North Pacific (WNP), Eastern North Pacific (ENP), and North Atlantic (NAT). The genesis numbers of tropical cyclone at each basin increased distinctively at its maximum active phase of BSISO, showing the significant modulation of ISO on tropical cyclone genesis in the Northern Hemisphere. Analysis of the individual contribution of each factors in GPI reveals that the vertical velocity at 500hPa of DGPI and the relative humidity at 600hPa of ENGPI play the most important role in modulating TCG by BSISO. The SST and maximum potential intensity of ENGPI did not represent important physical processes by which the BSISO circulation anomalies affect TCG. The evolution of eight-phase BSISO with intraseasonal prediction of TCG revealed great improvement by DGPI. The evolution of TCG associated with BSISO by basins, such as NIO, WNP, ENP, and NAT showed good performance in featuring the TCG variability, indicating the possibility of improving subseasonal prediction of TCG by our new DGPI.

Geophysical and petrological modelling of the structure and composition of the crust and upper mantle in complex geodynamic settings: The Tyrrhenian Sea and surroundings

NASA Astrophysics Data System (ADS)

Panza, G. F.; Peccerillo, A.; Aoudia, A.; Farina, B.

2007-01-01

Information on the physical and chemical properties of the lithosphere-asthenosphere system (LAS) can be obtained by geophysical investigation and by studies of petrology-geochemistry of magmatic rocks and entrained xenoliths. Integration of petrological and geophysical studies is particularly useful in geodynamically complex areas characterised by abundant and compositionally variable young magmatism, such as in the Tyrrhenian Sea and surroundings. A thin crust, less than 10 km, overlying a soft mantle (where partial melting can reach about 10%) is observed for Magnaghi, Vavilov and Marsili, which belong to the Central Tyrrhenian Sea backarc volcanism where subalkaline rocks dominate. Similar characteristics are seen for the uppermost crust of Ischia. A crust about 20 km thick is observed for the majority of the continental volcanoes, including Amiata-Vulsini, Roccamonfina, Phlegraean Fields-Vesuvius, Vulture, Stromboli, Vulcano-Lipari, Etna and Ustica. A thicker crust is present at Albani - about 25 km - and at Cimino-Vico-Sabatini — about 30 km. The structure of the upper mantle, in contrast, shows striking differences among various volcanic provinces. Volcanoes of the Roman region (Vulsini-Sabatini-Alban Hills) sit over an upper mantle characterised by Vs mostly ranging from about 4.2 to 4.4 km/s. At the Alban Hills, however, slightly lower Vs values of about 4.1 km/s are detected between 60 and 120 km of depth. This parallels the similar and rather homogeneous compositional features of the Roman volcanoes, whereas the lower Vs values detected at the Alban Hills may reflect the occurrence of small amounts of melts within the mantle, in agreement with the younger age of this volcano. The axial zone of the Apennines, where ultrapotassic kamafugitic volcanoes are present, has a mantle structure with high-velocity lid ( Vs ˜ 4.5 km/s) occurring at the base of a 40-km-thick crust. Beneath the Campanian volcanoes of Vesuvius and Phlegraean Fields, the mantle

Genesis field operational test : final evaluation report

DOT National Transportation Integrated Search

1997-09-01

This document is the Final Evaluation Report for the Genesis Advanced Traveler Information System (ATIS) Field Operational Test (FOT). Genesis was one of the early projects sponsored by the US Department of Transportation (USDOT) Intelligent Transpor...

Cutting of Gold Foil in the Genesis Laboratory

NASA Image and Video Library

2005-02-15

The facility for storing and examining Genesis solar wind samples consists of two adjacent laboratories. In these laboratories, the cutting of gold foil to be used in the gathering of the solar wind dust aboard the Genesis spacecraft. Views include: The process of cutting gold foil to be used aboard the Genesis spacecraft. The technicians use Gore-Tex suits with filters as to not contaminate the items.

New Results from the Flare Genesis Experiment

NASA Astrophysics Data System (ADS)

Rust, D. M.; Bernasconi, P. N.; Eaton, H. A.; Keller, C.; Murphy, G. A.; Schmieder, B.

2000-05-01

From January 10 to 27, 2000, the Flare Genesis solar telescope observed the Sun while suspended from a balloon in the stratosphere above Antarctica. The goal of the mission was to acquire long time series of high-resolution images and vector magnetograms of the solar photosphere and chromosphere. Images were obtained in the magnetically sensitive Ca I line at 6122 Angstroms and at H-alpha (6563 Angstroms). The FGE data were obtained in the context of Max Millennium Observing Campaign #004, the objective of which was to study the ``Genesis of Solar Flares and Active Filaments/Sigmoids." Flare Genesis obtained about 26,000 usable images on the 8 targeted active regions. A preliminary examination reveals a good sequence on an emerging flux region and data on the M1 flare on January 22, as well as a number of sequences on active filaments. We will present the results of our first analysis efforts. Flare Genesis was supported by NASA grants NAG5-4955, NAG5-5139, and NAG5-8331 and by NSF grant OPP-9615073. The Air Force Office of Scientific Research and the Ballistic Missile Defense Organization supported early development of the Flare Genesis Experiment.

Deep crustal structure beneath large igneous provinces and the petrologic evolution of flood basalts

NASA Astrophysics Data System (ADS)

Ridley, Victoria A.; Richards, Mark A.

2010-09-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ˜ 6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ˜5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp ˜ 7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hot spots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ˜6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ˜15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as "underplating," are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby

Deep Crustal Structure beneath Large Igneous Provinces and the Petrologic Evolution of Flood Basalts

NASA Astrophysics Data System (ADS)

Richards, M. A.; Ridley, V. A.

2010-12-01

We present a review of seismological constraints on deep crustal structures underlying large igneous provinces (LIPs), largely from wide-angle seismic refraction surveys. The main purpose of this review is to ascertain whether this seismic evidence is consistent with, or contrary to, petrological models for the genesis of flood basalt lavas. Where high-quality data are available beneath continental flood basalt (CFB) provinces (Emeishan, Columbia River, Deccan, Siberia), high-velocity structures (Vp ~6.9-7.5 km/sec) are typically found immediately overlying the Moho in layers of order ~5-15 km thick. Oceanic plateau (OP) LIPs exhibit similar layers, with a conspicuous layer of very high crustal velocity (Vp~7.7 km/sec) beneath the enormous Ontong-Java plateau. These structures are similar to inferred ultramafic underplating structures seen beneath active hotspots such as Hawaii, the Marquesas, and La Reunion. Petrogenetic models for flood basalt volcanism based on hot plume melting beneath mature lithosphere suggest that these deep seismic structures may consist in large part of cumulate bodies of olivine and clinopyroxene which result from ponding and deep-crustal fractionation of ultramafic primary melts. Such fractionation is necessary to produce basalts with typical MgO contents of ~6-8%, as observed for the vast bulk of observed flood basalts, from primary melts with MgO contents of order ~15-18% (or greater) such as result from hot, deep melting beneath the lithosphere. The volumes of cumulate bodies and ultramafic intrusions in the lowermost crust, often described in the literature as “underplating,” are comparable to those of the overlying basaltic formations, also consistent with petrological models. Further definition of the deep seismic structure beneath such prominent LIPs as the Ontong-Java Plateau could place better constraints on flood basalt petrogenesis by determining the relative volumes of ultramafic bodies and basaltic lavas, thereby better

Petrology and In Situ Trace Element Chemistry of a Suite of R Chondrites

NASA Astrophysics Data System (ADS)

Mittlefehldt, D. W.; Peng, Z. X.; Torrano, Z. A.

2015-07-01

Your eyes are not deceiving you: Duck has submitted an abstract to a chondrite session. We will present the results of our petrological and compositional studies of R chondrites of diverse petrological type.

Plant cutin genesis: unanswered questions.

PubMed

Domínguez, Eva; Heredia-Guerrero, José A; Heredia, Antonio

2015-09-01

The genesis of cutin, the main lipid polymer present in the biosphere, has remained elusive for many years. Recently, two main approaches have attempted to explain the process of cutin polymerization. One describes the existence of an acyltransferase cutin synthase enzyme that links activated monomers of cutin in the outer cell wall, while the other shows that plant cutin is the final result of an extracellular nonenzymatic self-assembly and polymerizing process of cutin monomers. In this opinion article, we explain both models and suggest that they could be pieces of a more complex biological scenario. We also highlight their different characteristics and current limitations, and suggest a potential synergism of both hypotheses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genesis of folia in a non-thermal epigenic cave (Matanzas, Cuba)

NASA Astrophysics Data System (ADS)

D'Angeli, Ilenia Maria; De Waele, Jo; Melendres, Osmany Ceballo; Tisato, Nicola; Sauro, Francesco; Gonzales, Esteban Ruben Grau; Bernasconi, Stefano M.; Torriani, Stefano; Bontognali, Tomaso R. R.

2015-01-01

Folia are an unusual speleothem type resembling inverted cups or bracket fungi. The mechanism of folia formation is not fully understood and is the subject of an ongoing debate. This study focuses on an occurrence of folia present in Santa Catalina Cave, a non-thermal epigenic cave located close to Matanzas (Cuba). The sedimentology, morphology, petrology, permeability and geochemistry of these folia have been studied to gain new insight on the processes leading to their development. It is concluded that folia in Santa Catalina Cave formed at the top of a fluctuating water body, through CO2-degassing or evaporation, which may have been enhanced by the proximity to cave entrances. Two observations strongly support our conclusions. (1) When compared to other subaqueous speleothems (e.g. cave clouds) present in the same rooms, folia occur exclusively within a limited vertical interval that likely represents an ancient water level. Folia occur together with calcite rafts and tower cones that developed, respectively, on top of and below the water level. This suggests that a fluctuating interface is required for folia formation. (2) The measured permeability of the folia is too high to trap gas bubbles. Thus, in contrast to what has been proposed in other studies, trapped bubbles of CO2 cannot be invoked as the key factor determining the genesis and morphology of folia in this subaqueous environment.

33 CFR 147.825 - Chevron Genesis Spar safety zone.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Chevron Genesis Spar safety zone... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.825 Chevron Genesis Spar safety zone. (a) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N, 90...

33 CFR 147.825 - Chevron Genesis Spar safety zone.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Chevron Genesis Spar safety zone... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.825 Chevron Genesis Spar safety zone. (a) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N, 90...

33 CFR 147.825 - Chevron Genesis Spar safety zone.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Chevron Genesis Spar safety zone... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.825 Chevron Genesis Spar safety zone. (a) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N, 90...

33 CFR 147.825 - Chevron Genesis Spar safety zone.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Chevron Genesis Spar safety zone... (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.825 Chevron Genesis Spar safety zone. (a) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N, 90...

Mind Over Magma: The Story of Igneous Petrology

NASA Astrophysics Data System (ADS)

Snyder, Don

2004-01-01

In the centuries that enquiring minds have studied and theorized about igneous rocks, much progress has been made, both in accumulating observations and in developing theories. Yet, writing a history of this progress is a daunting undertaking. The volume of the literature is vast and in multiple languages; the various lines of inquiry are diverse and complex; and the nomenclature is sometimes abstruse. On top of these challenges, many of its principal issues have yet to find a definitive consensus. With the exception of a few topical studies, historians of science have virtually avoided the subject. In Mind Over Magma: The Story of Igneous Petrology, Davis Young has taken on the challenge of writing a comprehensive survey of the study of igneous rocks, and the result has been a remarkable book of meticulous scholarship. Igneous petrology is a vast subject, and it is not obvious how best to organize its history. Young takes a topical approach, generally grouping together various studies by either the problem being investigated or the method of attack. These topics span the earliest times to the present, with an emphasis on recurring themes, such as the causes of magmatic diversity and the origins of the granitic rocks. The range of topics includes most of the subjects central to the field over its history. As much as is practical, topics are discussed in chronological order, and along the way, the reader is treated to biographical sketches of many of the key contributors. This organization proves effective in dealing with the multitude of concepts.

Petrology of the Crystalline Rocks Hosting the Santa Fe Impact Structure

NASA Technical Reports Server (NTRS)

Schrader, C. M.; Cohen, B. A.

2010-01-01

We collected samples from within the area of shatter cone occurrence and for approximately 8 kilometers (map distance) along the roadway. Our primary goal is to date the impact. Our secondary goal is to use the petrology and Ar systematics to provide further insight into size and scale of the impact. Our approach is to: Conduct a detailed petrology study to identify lithologies that share petrologic characteristics and tectonic histories but with differing degrees of shock. Obtain micro-cores of K-bearing minerals from multiple samples for Ar-40/Ar-39 analysis. Examine the Ar diffusion patterns for multiple minerals in multiple shocked and control samples. This will help us to better understand outcrop and regional scale relationships among rocks and their responses to the impact event.

Solar composition from the Genesis Discovery Mission

PubMed Central

Burnett, D. S.; Team, Genesis Science

2011-01-01

Science results from the Genesis Mission illustrate the major advantages of sample return missions. (i) Important results not otherwise obtainable except by analysis in terrestrial laboratories: the isotopic compositions of O, N, and noble gases differ in the Sun from other inner solar system objects. The N isotopic composition is the same as that of Jupiter. Genesis has resolved discrepancies in the noble gas data from solar wind implanted in lunar soils. (ii) The most advanced analytical instruments have been applied to Genesis samples, including some developed specifically for the mission. (iii) The N isotope result has been replicated with four different instruments. PMID:21555545

Art, Education, and Community: Arts Genesis, Inc.

ERIC Educational Resources Information Center

Kestler, Carol S.

Arts Genesis, Inc. (AGI) forms partnerships with diverse communities to assist them in finding fulfillment through the arts by meeting their own self-defined needs; uses arts experiences to encourage discovery, creativity, and diversity; and continually strives for excellence in the arts and education. Arts Genesis grew out of "Project…

ORE's GENeric Evaluation SYStem: GENESYS 1988-89.

ERIC Educational Resources Information Center

Baenen, Nancy; And Others

GENESYS--GENeric Evaluation SYStem--is a method of streamlining data collection and evaluation through the use of computer technology. GENESYS has allowed the Office of Research and Evaluation (ORE) of the Austin (Texas) Independent School District to evaluate a multitude of contrasting programs with limited resources. By standardizing methods and…

Mineralogical, petrological and geochemical aspects of alkaline and alkaline-carbonatite associations from Brazil

NASA Astrophysics Data System (ADS)

Morbidelli, L.; Gomes, C. B.; Beccaluva, L.; Brotzu, P.; Conte, A. M.; Ruberti, E.; Traversa, G.

1995-12-01

A general description of Mesozoic and Tertiary (Fortaleza) Brazilian alkaline and alkaline-carbonatite districts is presented with reference to mineralogy, petrology, geochemistry and geochronology. It mainly refers to scientific results obtained during the last decade by an Italo-Brazilian research team. Alkaline occurrences are distributed across Brazilian territory from the southern (Piratini, Rio Grande do Sul State) to the northeastern (Fortaleza, Ceará State) regions and are mainly concentrated along the borders of the Paraná Basin generally coinciding with important tectonic lineaments. The most noteworthy characteristics of these alkaline and alkaline-carbonatite suites are: (i) prevalence of intrusive forms; (ii) abundance of cumulate assemblages (minor dunites, frequent clinopyroxenites and members of the ijolite series) and (iii) abundance of evolved rock-types. Many data demonstrate that crystal fractionation was the main process responsible for magma evolution of all Brazilian alkaline rocks. A hypothesis is proposed for the genesis of carbonatite liquids by immiscibility processes. The incidence of REE and trace elements for different major groups of lithotypes, belonging both to carbonatite-bearing and carbonatite-free districts, are documented. Sr and preliminary Nd isotopic data are indicative of a mantle origin for the least evolved magmas of all the studied occurrences. Mantle source material and melting models for the generation of the Brazilian alkaline magma types are also discussed.

Mechanisms of genesis of variant translocation in chronic myeloid leukemia are not correlated with ABL1 or BCR deletion status or response to imatinib therapy.

PubMed

Richebourg, Steven; Eclache, Virginie; Perot, Christine; Portnoi, Marie-France; Van den Akker, Jacqueline; Terré, Christine; Maareck, Odile; Soenen, Valérie; Viguié, Franck; Laï, Jean-Luc; Andrieux, Joris; Corm, Sélim; Roche-Lestienne, Catherine

2008-04-15

Many published studies have indicated that various mechanisms could be involved in the genesis of variant chronic myelogeneous leukemia (CML) translocations. These are mainly one-step or two-step mechanisms, associated or not with deletions adjacent to the translocation junction on der(9) or der(22) chromosomes (or both). Based on the mechanism of genesis, it has been suggested that the complexity may affect the occurrence of ABL1 and BCR deletions (either or both), or may be associated with the CML disease course, and thus could determine the response to imatinib therapy. Through a retrospective molecular cytogenetic study of 41 CML patients with variant Philadelphia chromosome (Ph), we explored the genesis of these variant rearrangements and analyzed the correlation with deletion status and imatinib efficiency. Our results confirmed that the one-step mechanism is the most frequent, evidenced in 30 of 41 patients (73%); 3 patients demonstrated other more complex multistep events and 8 patients (19.5%) harbored ABL1 or BCR deletions that are not significantly associated with the complexity of translocation genesis. We also found no association between one-step, two-step, or multistep mechanisms and the response to imatinib therapy.

Petrological, geochemical, and stable isotope constraints on the genesis of the Miocene igneous rocks of Chetaibi and Cap de Fer (NE Algeria)

NASA Astrophysics Data System (ADS)

Laouar, R.; Boyce, A. J.; Arafa, M.; Ouabadi, A.; Fallick, A. E.

2005-06-01

Miocene igneous rocks (diorites, andesites, dacites, rhyolites and microgranites) of Chetaibi and Cap de Fer massif, NE Algeria, are high-K calc-alkaline to shoshonitic rocks. Fresh diorites have δ 34S and δ 18O values ranging between -2.5‰ and +5.9‰, +6.5‰ and +6.7‰ respectively, indicating a mantle origin. The relatively low δ 34S values (-5.4‰ to -12.2‰) and high δ 18O (+8.3‰ to +9.0‰) of altered diorites indicate the input of a crustal component to the initial magma. The microgranites' I-type signature is indicated by the geochemical data and the δ 34S and δ 18O values of -1.2‰ and -3.6‰, and +7.8‰ to +10.4‰ respectively. The andesites show a large variation of δ 34S, between -33.2‰ and +25.7‰. Massive andesites with δ 34S between +6.8‰ and +7.6‰ preserve a 34S-enriched mantle signature. The δ 34S of the lava flows between +25.7‰ and +25.8‰ are attributed to open system magma degassing, whereas the low δ 34S of two andesitic dyke samples (-13.7‰ and -33.2‰) strongly suggest a crustal sulphur input. High δ 18O (+9.2‰ to +15.7‰) of andesites indicate post-magmatic alteration (mainly silicification); the flyschs with δ 18O between of +13.3‰ and +21.7‰ are most likely the contaminant. Quartz veins within the andesites gave a δ 18O value of +23.0‰ while silica-filling vesicles yielded a value of +13.8‰. Initial Sr-isotope data are rather high for all the rocks (diorites: 0.707-0.708, andesites: 0.707-0.710, and microgranites and rhyolites: 0.717-0.719), and because geochemical and stable isotope data do not indicate a substantial amount of crustal assimilation, an extensive enrichment of the mantle source by subducted sediments is called for. A metasomatized-mantle source, characterized by high radiogenic Sr and relatively high δ 18O, has also been indicated for the genesis of similar Tertiary igneous rocks in the Western Mediterranean basin, e.g. the Volcanic Province of southeasten Spain [Benito, R

GENESIS: GPS Environmental and Earth Science Information System

NASA Technical Reports Server (NTRS)

Hajj, George

1999-01-01

This presentation reviews the GPS ENvironmental and Earth Science Information System (GENESIS). The objectives of GENESIS are outlined (1) Data Archiving, searching and distribution for science data products derived from Space borne TurboRogue Space Receivers for GPS science and other ground based GPS receivers, (2) Data browsing using integrated visualization tools, (3) Interactive web/java-based data search and retrieval, (4) Data subscription service, (5) Data migration from existing GPS archived data, (6) On-line help and documentation, and (7) participation in the WP-ESIP federation. The presentation reviews the products and services of Genesis, and the technology behind the system.

Cosmological bounce and Genesis beyond Horndeski

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

Kolevatov, R.; Mironov, S.; Volkova, V.

2017-08-01

We study 'classical' bouncing and Genesis models in beyond Horndeski theory. We give an example of spatially flat bouncing solution that is non-singular and stable throughout the whole evolution. We also provide an example of stable geodesically complete Genesis with similar features. The model is arranged in such a way that the scalar field driving the cosmological evolution initially behaves like full-fledged beyond Horndeski, whereas at late times it becomes a massless scalar field minimally coupled to gravity.

Cleaning Study of Genesis Sample 60487

NASA Technical Reports Server (NTRS)

Kuhlman, Kim R.; Rodriquez, M. C.; Gonzalez, C. P.; Allton, J. H.; Burnett, D. S.

2013-01-01

The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. Particles of Genesis wafers, brine from the Utah Testing Range and an organic film have deleterious effects on many of the high-resolution instruments that have been developed to analyze the implanted solar wind. We have conducted a correlative microscopic study of the efficacy of cleaning Genesis samples with megasonically activated ultrapure water and UV/ozone cleaning. Sample 60487, the study sample, is a piece of float-zone silicon from the B/C array approximately 4.995mm x 4.145 mm in size

Petrology of Anomalous Mafic Achondrite Polymict Breccia Pasamonte

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Berger, E. L.; Le, L.

2017-01-01

The most common asteroidal igneous meteorites are eucrite-type basalts and gabbros - rocks composed of ferroan pigeonite and augite, calcic plagioclase, silica, ilmenite, troilite, Ca-phosphate, chromite and Fe-metal [1]. These rocks are thought to have formed on a single asteroid, widely considered to be 4 Vesta, along with howardites and diogenites [1, 2]. High precision O-isotopic analyses have shown that some eucrites have small, well-resolved O-isotopic differences from the group mean [3-5]. These Oanomalous eucrites are thought to hail from asteroidal parents that are distinct from that of eucrites [5]. Three O-anomalous eucrites are PCA 82502, PCA 91007 (paired) and Pasamonte, all of which have the same O-isotopic composition [5, 6]. Our petrologic studies have shown that PCA 82502 and PCA 91007 have well-resolved anomalies in low-Ca pyroxene Fe/Mn compared to eucrites [6]. Divalent Mn and Fe are homologous species that do not greatly fractionate during igneous processes; mafic mineral Fe/Mn can be used to fingerprint parent object sources [7]. Previous petrological studies of Pasamonte [8-10] have not yielded sufficiently precise Fe/Mn ratios to allow distinction of anomalies of the scale of those found for the PCA basalts. We have begun petrological study of Pasamonte for comparison with our results on normal and anomalous eucrites [6], and to constrain its origin.

Concentrating Solar Power Projects - Genesis Solar Energy Project |

Science.gov Websites

Concentrating Solar Power | NREL Genesis Solar Energy Project This page provides information on the Genesis Solar Energy Project, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. The Project includes two 125-MW units incorporating

Petrology and Geochemistry of the NWA 3368 Eucrite

NASA Astrophysics Data System (ADS)

Gardner, K. G.; Lauretta, D. S.; Hill, D. H.; Goreva, J. S.; Domanik, K. J.; Franchi, I. A.; Drake, M. J.

2006-03-01

We report the petrology and geochemistry of NWA 3368, a new non-cumulate, monomict eucrite breccia with a variety of clast sizes and a pink-tinted matrix. Analytical techniques include electron microprobe, INAA, and ICP-MS.

Igneous and metamorphic petrology in the field: a problem-based, writing-intensive alternative to traditional classroom petrology

NASA Astrophysics Data System (ADS)

DeBari, S. M.

2011-12-01

The Geology Department at Western Washington University (~100 geology majors) offers field and classroom versions of its undergraduate petrology course. This is a one-quarter course (igneous and metamorphic petrology) with mineralogy as a prerequisite. The field version of the course is offered during the three weeks prior to fall quarter and the classroom version is offered in spring quarter. We take 15-20 students around the state of Washington, camping at different outcrop sites where students integrate observational skills, petrologic knowledge, and writing. Petrogenetic associations in various tectonic settings provide the theme of the course. We compare ophiolites vs. arc sequences (volcanic, plutonic, and metamorphic rocks), S- vs. I-type granitoids (plutonic rocks and associated metamorphic rocks), Barrovian vs. Buchan vs. subduction zone metamorphism of different protoliths, and flood-basalt vs. active-arc volcanism. Some basics are covered in the first day at WWU, followed by 17 days of field instruction. Lecture is integrated with outcrop study in the field. For example, students will listen to a lecture about magma differentiation processes as they examine cumulate rocks in the Mt. Stuart batholith, and a lecture about metamorphic facies as they study blueschist facies rocks in the San Juan Islands. Students study multiple outcrops around a site for 1-4 days. They then use their observations (sketches and written descriptions of mineral assemblages, rock types, rock textures, etc.) and analysis techniques (e.g. geochemical data plotting, metamorphic protolith analysis) to write papers in which the data are interpreted in terms of a larger tectonic problem. In advance of the writing process, students use group discussion techniques such as whiteboarding to share their observational evidence and explore interpretations. Student evaluations indicate that despite the intense pace of the course, they enjoy it more. Students also feel that they retain more

Thermal and petrologic constraints on the lower crustal melt accumulation in the Salton Sea Geothermal Field

NASA Astrophysics Data System (ADS)

Karakas, O.; Dufek, J.; Mangan, M.; Wright, H. M. N.

2014-12-01

Heat transfer in active volcanic areas is governed by complex coupling between tectonic and magmatic processes. These two processes provide unique imprints on the petrologic and thermal evolution of magma by controlling the geometry, depth, longevity, composition, and fraction of melt in the crust. The active volcanism, tectonic extension, and significantly high surface heat flow in Salton Sea Geothermal Field, CA, provides information about the dynamic heat transfer processes in its crust. The volcanism in the area is associated with tectonic extension over the last 500 ka, followed by subsidence and sedimentation at the surface level and dike emplacement in the lower crust. Although significant progress has been made describing the tectonic evolution and petrology of the erupted products of the Salton Buttes, their coupled control on the crustal heat transfer and feedback on the melt evolution remain unclear. To address these concepts, we develop a two-dimensional finite volume model and investigate the compositional and thermal evolution of the melt and crust in the Salton Sea Geothermal Field through a one-way coupled thermal model that accounts for tectonic extension, lower crustal magma emplacement, sedimentation, and subsidence. Through our simulations, we give quantitative estimates to the thermal and compositional evolution and longevity of the lower crustal melt source in the crustal section. We further compare the model results with petrologic constraints. Our thermal balance equations show that crustal melting is limited and the melt is dominated by mantle-derived material. Similarly, petrologic work on δ18O isotope ratios suggests fractional crystallization of basalt with minor crustal assimilation. In addition, we suggest scenarios for the melt fraction, composition, enthalpy release, geometry and depth of magma reservoirs, their temporal evolution, and the timescales of magmatic storage and evolution processes. These parameters provide the source

The Birth of a Cratonic Core: Petrologic Evolution of the Hadean-Eoarchean Acasta Gneiss Complex

NASA Astrophysics Data System (ADS)

Reimink, J. R.; Chacko, T.; Davies, J.; Pearson, D. G.; Stern, R. A.; Heaman, L. M.; Carlson, R.; Shirey, S. B.

2016-12-01

Granitoid magmatism within the 4.02-3.6 Ga Acasta Gneiss Complex records distinct whole-rock compositional changes during the building the Slave Craton. Previously1,2 we suggested that these signatures implied petrologic changes from initiation of evolved crust formation in an Iceland-like setting to partial melting of hydrated mafic crust at increasing depth through time, culminating in relatively voluminous magmatism at 3.6 Ga. Increasing La/Yb in these rocks suggest increasing depth of melting (and increasing residual garnet content) with time, ending in emplacement of rocks comparable to other Archean TTG suites3, with both high pressure (high La/Yb) and low pressure (low La/Yb) rocks represented at 3.6 Ga. Data from rocks with variable La/Yb that crystallized 3.6 Ga allow us to evaluate potential mechanisms for formation of rocks of this age such as subduction/accretion or intracrustal melting/delamination. Despite major and trace element compositional and age variability, zircon oxygen isotope compositions from a wide variety of rocks are extremely consistent (+6.0-6.5 ‰ from 3.9-2.9 Ga), implying a similar source, one that had been altered by surface waters1. Potential source rocks include the upper portion of oceanic crust, which contains a large portion of mafic crust that had been altered at low temperatures (e.g., 4). Paired whole rock and zircon radiogenic isotopic data are especially sensitive to the extent of pre-existing felsic material in the region, as well as the longevity of primary, basaltic rocks prior to their reworking into more evolved crust. New paired zircon Hf and whole rock Nd isotope data collected from these samples show variably unradiogenic signatures and allow an exploration of similarities and disparities between crust formation in the Acasta Gneiss Complex and other Paleoarchean-Mesoarchean crustal blocks. [1] Reimink et al., 2016. Precambrian Research 281, 453-472. [2] Reimink et al., 2014 Nature Geoscience 7, 529-533. [3

Petrology and In Situ Trace Element Chemistry of a Suite of R Chondrites

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Peng, Z. X.; Torrano, Z. A.

2015-01-01

Rumuruti (R) chondrites are characterized by low chondrule/matrix modal ratios, high oxidation state, small mean chondrule size, abundant sulfides and low metal contents, and are of petrologic types 3 to 6 [1, 2]. LAP 04840 (R5, [3]) and MIL 11207 (R6), contain the high-T hydrous phases amphibole and mica [3, 4]; not all equilibrated R chondrites contain these [2]. R chondrites thus can provide evidence on whether there are compositional effects caused by high-T, high-fluid metamorphism of nebular materials. We are investigating a suite of R chondrites of diverse petrologic grades to further understand the nature of the metamorphic processes that engendered them [5]. We report on our petrological studies, plus preliminary in situ analyses of trace elements in amphibole-bearing R chondrites.

[Petrological Analysis of Astrophysical Dust Analog Evolution

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1997-01-01

This project "Petrological analysis of astrophysical dust analog evolution" was initiated to try to understand the vapor phase condensation, and the nature of the reaction products, in circumstellar environments, such as the solar nebula 4,500 Myrs ago, and in the interstellar medium. Telescope-based infrared [IR] spectroscopy offers a broad-scale inventory of the various types of dust in these environments but no details on small-scale variations in terms of chemistry and morphology and petrological phase relationships. Vapor phase condensation in these environments is almost certainly a non-equilibrium process. The main challenge to this research was to document the nature of this process that, based on astrophysical observations, seems to yield compositionally consistent materials. This observation may suggest a predictable character during non-equilibrium condensation. These astrophysical environments include two chemically distinct, that is, oxygen-rich and carbon-rich environments. The former is characterized by silicates the latter by carbon-bearing solids. According to cosmological models of stellar evolution circumstellar dust accreted into protoplanets wherein thermal and/or aqueous processes will alter the dust under initially, non-equilibrium conditions.

Petrology and Geochemistry of LEW 88663 and PAT 91501: High Petrologic L Chondrites

NASA Astrophysics Data System (ADS)

Mittlefehldt, D. W.; Lindstrom, M. M.; Field, S. W.

1993-07-01

Primitive achondrites (e.g., Acapulco, Lodran) are believed to be highly metamorphosed chondritic materials, perhaps up to the point of anatexis in some types. Low petrologic grade equivalents of these achondrites are unknown, so the petrologic transition from chondritic to achondritic material cannot be documented. However, there are rare L chondrites of petrologic grade 7 that may have experienced igneous processes, and study of these may yield information relevant to the formation of primitive achondrites, and perhaps basaltic achondrites, from chondritic precursors. We have begun the study of the L7 chondrites LEW 88663 and PAT 91501 as part of our broader study of primitive achondrites. Here, we present our preliminary petrologic and geochemical data on these meteorites. Petrology and Mineral Compositions: LEW 88663 is a granular achondrite composed of equant, subhedral to anhedral olivine grains poikilitically enclosed in networks of orthopyroxene and plagioclase. Small grains of clinopyroxene are spatially associated with orthopyroxene. Troilite occurs as large anhedral and small rounded grains. The smaller troilite grains are associated with the orthopyroxene-plagioclase networks. PAT 91501 is a vesicular stone containing centimeter-sized troilite +/- metal nodules. Its texture consists of anhedral to euhedral olivine grains, anhedral orthopyroxene grains (some with euhedral clinopyroxene overgrowths), anhedral to euhedral clinopyroxene, and interstitial plagioclase and SiO2-Al2O3-K2O- rich glass. In some areas, olivine is poikilitically enclosed in orthopyroxene. Fine-grained troilite, metal, and euhedral chromite occur interstitial to the silicates. Average mineral compositions for LEW 88663 are olivine Fo(sub)75.8, orthopyroxene Wo(sub)3.4En(sub)76.2Fs(sub)20.4, clinopyroxene Wo(sub)42.6En(sub)47.8Fs(sub)9.6, plagioclase Ab(sub)75.0An(sub)21.6Or(sub)3.4. Mineral compositions for PAT 91501 are olivine Fo(sub)73.8, orthopyroxene Wo(sub)4.5En(sub)74.8Fs

Reconstruction of the Genesis Entry

NASA Technical Reports Server (NTRS)

Desai, Prasun N.; Qualls, Garry D.; Schoenenberger, Mark

2005-01-01

This paper provides an overview of the findings from a reconstruction analysis of the Genesis capsule entry. First, a comparison of the atmospheric properties (density and winds) encountered during the entry to the pre-entry profile is presented. The analysis that was performed on the video footage (obtained from the tracking stations at UTTR) during the descent is then described from which the Mach number at the onset of the capsule tumble was estimated following the failure of the drogue parachute deployment. Next, an assessment of the Genesis capsule aerodynamics that was extracted from the video footage is discussed, followed by a description of the capsule hypersonic attitude that must have occurred during the entry based on examination of the recovered capsule heatshield. Lastly, the entry trajectory reconstruction that was performed is presented.

Petrological Mapping of the Crater Boguslawsky

NASA Astrophysics Data System (ADS)

Wöhler, C.; Evdokimova, N. A.; Feoktistova, E. A.; Grumpe, A.; Kapoor, K.; Berezhnoy, A. A.; Shevchenko, V. V.

2015-10-01

An analysis of orbital spectral data of the crater Boguslawsky, the intended target region of the Russian Luna-Glob mission, is performed. We have constructed a high- resolution DEM of the crater Boguslawsky, based on which the temperature regime on the surface is investigated. The depth of the OH absorption feature is analysed.The content of the main elements is estimated, and a petrologic map is constructed accordingly.

PETRO.CALC.PLOT, Microsoft Excel macros to aid petrologic interpretation

USGS Publications Warehouse

Sidder, G.B.

1994-01-01

PETRO.CALC.PLOT is a package of macros which normalizes whole-rock oxide data to 100%, calculates the cation percentages and molecular proportions used for normative mineral calculations, computes the apices for ternary diagrams, determines sums and ratios of specific elements of petrologic interest, and plots 33 X-Y graphs and five ternary diagrams. PETRO.CALC.PLOT also may be used to create other diagrams as desired by the user. The macros run in Microsoft Excel 3.0 and 4.0 for Macintosh computers and in Microsoft Excel 3.0 and 4.0 for Windows. Macros provided in PETRO.CALC.PLOT minimize repetition and time required to recalculate and plot whole-rock oxide data for petrologic analysis. ?? 1994.

Genesis Noble Gas Measurements

NASA Technical Reports Server (NTRS)

Hohenberg, Charles M.

2005-01-01

The original thrust of our Genesis funding was to extend and refine the noble gas analytical capabilities of this laboratory to improve the precision and accuracy of noble gas measurements in order to optimize the scientific return from the Genesis Mission. This process involved both instrumental improvement (supplemented by a SRLIDAP instrument grant) and refinement of technique. The Genesis landing mishap shifted our emphasis to the irregular aluminum heat shield material from the flat collector wafers. This has required redesign of our laser extraction cells to accommodate the longer focal lengths required for laser extraction from non-flat surfaces. Extraction of noble gases from solid aluminum surfaces, rather than thin coatings on transparent substrates has required refinement of controlled-depth laser ablation techniques. Both of these bring new problems, both with potentially higher blanks form larger laser cells and the larger quantities of evaporated aluminum which can coat the sapphire entrance ports. This is mainly a problem for the heavy noble gases where larger extraction areas are required, necessitating the new aluminum vapor containment techniques described below. With the Genesis Mission came three new multiple multiplier noble gas mass spectrometers to this laboratory, one built solely by us (Supergnome-M), one built in collaboration with Nu-Instruments (Noblesse), and one built in collaboration with GVI (Helix). All of these have multiple multiplier detection sections with the Nu-Instruments using a pair of electrostatic quad lenses for isotope spacing and the other two using mechanically adjustable positions for the electron multipliers. The Supergnome-M and Noblesse are installed and running. The GVI instrument was delivered a year late (in March 2005) and is yet to be installed by GVI. As with all new instruments there were some initial development issues, some of which are still outstanding. The most serious of these are performance issues

A Simulated Research Problem for Undergraduate Metamorphic Petrology.

ERIC Educational Resources Information Center

Amenta, Roddy V.

1984-01-01

Presents a laboratory problem in metamorphic petrology designed to simulate a research experience. The problem deals with data on scales ranging from a geologic map to hand specimens to thin sections. Student analysis includes identifying metamorphic index minerals, locating their isograds on the map, and determining the folding sequence. (BC)

Small Particulate Contamination Survey Of Genesis Flight Sample 61423

NASA Technical Reports Server (NTRS)

Kuhlman, K. R.; Schmeling, M.; Gonzalez, C. P.; Allums, K. K.; Allton, J. H.; Burnett, D. S.

2016-01-01

The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind stop in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. We continue to work with the community of scientists analyzing Genesis samples using our unique laboratory facilities -- and, where needed, our unique cleaning techniques -- to significantly enhance the science return from the Genesis mission. This work is motivated by the need to understand the submicron contamination on the collectors in the Genesis payload as recovered from the crash site in the Utah desert, and -- perhaps more importantly -- how to remove it. We continue to evaluate the effectiveness of the wet-chemical "cleaning" steps used by various investigators, to enable them to design improved methods of stripping spacecraft and terrestrial contamination from surfaces while still leaving the solar-wind signal intact.

A Virtual Petrological Microscope for All Apollo 11 Lunar Samples

NASA Technical Reports Server (NTRS)

Pillnger, C. T.; Tindle, A. G.; Kelley, S. P.; Quick, K.; Scott, P.; Gibson, E. K.; Zeigler, R. A.

2014-01-01

A means of viewing, over the Internet, polished thin sections of every rock in the Apollo lunar sample collections via software, duplicaing many of the functions of a petrological microscope, is described.

76 FR 73748 - Genesis Capital, LLC and Northern Lights Fund Trust; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... SECURITIES AND EXCHANGE COMMISSION [Investment Company Act Release No. 29867; 812-13935] Genesis Capital, LLC and Northern Lights Fund Trust; Notice of Application November 21, 2011. AGENCY: Securities...: Genesis Capital, LLC (``Genesis Capital'' or the ``Adviser'') and Northern Lights Fund Trust (the ``Trust...

Petrology of the igneous rocks

NASA Technical Reports Server (NTRS)

Mccallum, I. S.

1987-01-01

Papers published during the 1983-1986 period on the petrology and geochemistry of igneous rocks are discussed, with emphasis on tectonic environment. Consideration is given to oceanic rocks, subdivided into divergent margin suites (mid-ocean ridge basalts, ridge-related seamounts, and back-arc basin basalts) and intraplate suites (oceanic island basalts and nonridge seamounts), and to igneous rocks formed at convergent margins (island arc and continental arc suites), subdivided into volcanic associations and plutonic associations. Other rock groups discussed include continental flood basalts, layered mafic intrusions, continental alkalic associations, komatiites, ophiolites, ash-flow tuffs, anorthosites, and mantle xenoliths.

Research on genesis of pyrite near the Permian-Triassic boundary in meishan, Zhejiang, China

USGS Publications Warehouse

Jiang, Y.-F.; Tang, Y.-G.; Chou, C.-L.

2006-01-01

The content and crystal forms of pyrite and sulfur isotope composition of pyrite sulfur as well as its vertical distribution near the Permian-Triassic (P/T) boundary in the Meishan section, Changxing county, Zhejiang province, China were studied using geological, petrological, mineralogical and geochemical methods (techniques). The result showed that the genesis of abundant pyrites in bed 24e2 at the uppermost part of the Changxing Formation in the Meishan section may be related to volcanic activity. In bed 24e2 of the Meishan section, pyrite has its highest content of 1.84% and the sulfur isotope composition has the highest ??34S value at + 2.2??? which is very similar to that of the average value of volcanic gas. There are some volcanic products such as ??-quartz, siliceous cylinders and siliceous spherules which coexisted with pyrites in beds 24e2 and 24f. It can be concluded that a large quantity of volcanic ash fell into the South China Sea and was incorporated into marine sediments during the formation of limestone at the uppermost part of the Changxing Formation. The volcanic eruption with massive amounts of H2S and S02 gas at the end of the Permian period resulted in the enrichment of H2S in the South China Sea areas. The reaction of H2S with reactive iron minerals formed the mass of abundant pyrites.

A Genesis Potential Index for Tropical Cyclone by Using Oceanic Parameters

NASA Astrophysics Data System (ADS)

Zhou, L.; Zhang, M.; Chen, D.; Wang, C.

2015-12-01

This study attempts to create a tropical cyclone (TC) genesis potential index (GPI) by considering oceanic parameters and necessary atmospheric parameters at the sea surface. Based on the general understanding of oceanic impacts on the TC genesis, many candidate factors are evaluated and discriminated, resulting in a new GPI index called GPIocean. GPIocean includes (1) the absolute vorticity at 1000 hPa, (2) the net sea surface longwave radiation, (3) the mean ocean temperature in the upper mixed layer, and (4) the depth of the 26°C isotherm. GPIocean is comparable to the existing GPIs in representing the TC genesis over the western North Pacific on climatological, interannual, and seasonal time scales. In the context of climate change, this new index is expected to be useful for evaluating the oceanic influences on the TC genesis, using ocean reanalysis products and/or climate model outputs.

Investigation of Backside Textures for Genesis Solar Wind Silicon Collectors

NASA Technical Reports Server (NTRS)

Gonzalez, C. P.; Burkett, P. J.; Rodriguez, M. C.; Allton, J. H.

2014-01-01

Genesis solar wind collectors were comprised of a suite of 15 types of ultrapure materials. The single crystal, pure silicon collectors were fabricated by two methods: float zone (FZ) and Czochralski (CZ). Because of slight differences in bulk purity and surface cleanliness among the fabrication processes and the specific vendor, it is desirable to know which variety of silicon and identity of vendor, so that appropriate reference materials can be used. The Czochralski method results in a bulk composition with slightly higher oxygen, for example. The CZ silicon array wafers that were Genesis-flown were purchased from MEMC Electronics. Most of the Genesis-flown FZ silicon was purchased from Unisil and cleaned by MEMC, although a few FZ wafers were acquired from International Wafer Service (IWS).

Influence of the Soil Genesis on Physical and Mechanical Properties

PubMed Central

Marschalko, Marian; Yilmaz, Işık; Fojtová, Lucie; Kubečka, Karel; Bouchal, Tomáš; Bednárik, Martin

2013-01-01

The paper deals with the influence of soil genesis on the physical-mechanical properties. The presented case study was conducted in the region of the Ostrava Basin where there is a varied genetic composition of the Quaternary geological structure on the underlying Neogeneous sediments which are sediments of analogous granulometry but different genesis. In this study, 7827 soil samples of an eolian, fluvial, glacial, and deluvial origin and their laboratory analyses results were used. The study identified different values in certain cases, mostly in coarser-grained foundation soils, such as sandy loam S4 (MS) and clayey sand F4 (CS). The soils of the fluvial origin manifest different values than other genetic types. Next, based on regression analyses, dependence was proved neither on the deposition depth (depth of samples) nor from the point of view of the individual foundation soil classes or the genetic types. The contribution of the paper is to point at the influence of genesis on the foundation soil properties so that engineering geologists and geotechnicians pay more attention to the genesis during engineering-geological and geotechnical investigations. PMID:23844398

Genesis of Ultra-High Pressure Garnet Pyroxenite in Orogenic Peridotites and its bearing on the Isotopic Chemical Heterogeneity in the Mantle Source of Oceanic Basalts

NASA Astrophysics Data System (ADS)

Varas Reus, María Isabel; Garrido, Carlos J.; Marchesi, Claudio; Bosch, Delphine; Hidas, Károly

2017-04-01

peridotites—- intimately mixed with peridotites by mantle convection. The present study reveals, however, that besides this exotic component of ancient recycled oceanic crust, the genesis of these pyroxenites requires a previously unnoticed component of recycled lower continental crust akin to the lower crustal section of the lithosphere where these UHP garnet pyroxenites now reside in. The results of this study provide a new recipe for the marble cake hypothesis for the genesis of UHP garnet pyroxenites in orogenic peridotites. Furthermore, it establishes a connection between the genesis of UHP pyroxenites, the composition of the continental crust and the generation of Earth's mantle heterogeneities. References: [1] Pearson, D. G., Davies, G. R. & Nixon, P. H. (1993). Geochemical constraints on the petrogenesis of diamond facies pyroxenites from the Beni Bousera peridotite massif, North Morocco. Journal of Petrology 34, 125-172. [2] Blichert-Toft, J., Albarède, F. & Kornprobst, J. (1999). Lu-Hf Isotope systematics of garnet pyroxenites from Beni Bousera, Morocco: implications for basalt origin. Science 283, 1303-1306. [3] Garrido, C. J. & Bodinier, J. L. (1999). Diversity of mafic rocks in the Ronda peridotite: Evidence for pervasive melt-rock reaction during heating of subcontinental lithosphere by upwelling asthenosphere. Journal of Petrology 40, 729-754. [4] Marchesi, C., Garrido, C.J., Bosch, D., Bodinier, J.-L., Gervilla, F., Hidas, K., 2013. Mantle refertilization by melts of crustal-derived garnet pyroxenite: Evidence from the Ronda peridotite massif, southern Spain. Earth and Planetary Science Letters 362, 66-75. doi: 10.1016/j.epsl.2012.11.047. [5] Marchesi, C., Dale, C.W., Garrido, C.J., Pearson, D.G., Bosch, D., Bodinier, J.-L., Gervilla, F., Hidas, K., 2014. Fractionation of highly siderophile elements in refertilized mantle: Implications for the Os isotope composition of basalts. Earth and Planetary Science Letters 400, 33-44. doi: 10.1016/j.epsl.2014

Equitable Estoppel: Its Genesis, Development, and Application in Government Contracting

DTIC Science & Technology

1988-09-30

NO. CCESSION NO. ,1. T:ITLE (include Security Classification) (UNCLASSIFIED) Equitable Estoppel : Its Genesis, Development, and Application in...sE.UkRm/ CLASSIFICATION OF THIS PAGE AFIT/CI’ "OVERPRINT" Equitable Estoppel : Its Genesis, Development, and Application in Government CoritractingQ By...John Cibinic,Jr. and Ralph C. Nash,Jr. Professors of Law 90 02 12 031 -Table of Contents 1. The Doctrine of Equitable Estoppel -................... 1

Genesis Reentry Observations and Data Analysis

NASA Technical Reports Server (NTRS)

Suggs, R. M.; Swift, W. R.

2005-01-01

The Genesis spacecraft reentry represented a unique opportunity to observe a "calibrated meteor" from northern Nevada. Knowing its speed, mass, composition, and precise trajectory made it a good subject to test some of the algorithms used to determine meteoroid mass from observed brightness. It was also a good test of an inexpensive set of cameras that could be deployed to observe future shuttle reentries. The utility of consumer-grade video cameras was evident during the STS-107 accident investigation, and the Genesis reentry gave us the opportunity to specify and test commercially available cameras that could be used during future reentries. This Technical Memorandum describes the video observations and their analysis, compares the results with a simple photometric model, describes the forward scatter radar experiment, and lists lessons learned from the expedition and implications for the Stardust reentry in January 2006 as well as future shuttle reentries.

Linking petrology and seismology of the southwest Greenland lithosphere

NASA Astrophysics Data System (ADS)

Lesher, C. E.; Vestergaard, C.; Brown, E.; Schutt, D.

2015-12-01

Mantle xenoliths from late-Proterozoic diamond-bearing kimberlitic dikes in the Kangerlussuaq, Sarfartoq and Maniitsoq areas of southwestern Greenland provide constraints on the composition and thermal state of lithospheric mantle beneath Greenland to depths of ~200 km [1]. Similarly, surface wave tomography studies carried out as part of the GLATIS project use a range of Rayleigh wave periods sensitive to structures at a similar depth interval within southwestern Greenland lithospheric mantle [2]. Here we link petrologic and seismologic constraints on the mantle lithosphere beneath Greenland utilizing methods of [3] that show that inferred chemical and mineralogical stratification inferred from petrology, showing mantle peridotite transitioning from garnet-free harzburgite to garnet lherzolite between ~70 and 180 km, cannot readily be resolved with fundamental mode Rayleigh waves. On the other hand, comparing phase velocities predicted from xenolith compositions, mineralogy and last equilibration temperatures and pressures, defining the continental geotherm during late-Proterozoic time, with those for the present-day mantle lithosphere suggest significant cooling of the cratonic mantle to a modern geotherm characterized by a heat flux of 30 mW/m2 and average crustal heat production of 0.3 mW/m3 [4]. These preliminary findings point to the weak dependence of shear wave velocities on mantle peridotite composition and mineralogy, and further illustrate its strong temperature dependence. Comparison of ancient and modern continental geotherms made possible by combining petrologic and seismological data, as shown here for southwest Greenland, provide additional constraints on secular cooling of cratonic regions linked to large-scale tectonic processes. [1] Bizzarro et al., 2003, CMP, 146; Sand et al., Lithos, 112. [2] Darbyshire et al., 2004, GJI, 158. [3] Schutt and Lesher, 2006, JGR, 111. [4] Meirerbachtol et al., 2015, JGR/ES, 120.

Contributions of tropical waves to tropical cyclone genesis over the western North Pacific

NASA Astrophysics Data System (ADS)

Wu, Liang; Takahashi, Masaaki

2018-06-01

The present study investigates the relationship between the tropical waves and the tropical cyclone (TC) genesis over the western North Pacific (WNP) for the period 1979-2011. Five wave types are considered in this study. It is shown that the TC genesis is strongly related to enhanced low-level vorticity and convection of tropical waves and significant difference are detected in the TC modulation by dynamic and thermodynamic components of the waves. More TCs tend to form in regions of waves with overlapping cyclonic vorticity and active convection. About 83.2% of TCs form within active phase of tropical waves, mainly in a single wave and two coexisting waves. Each wave type-related genesis accounts for about 30% of all TC geneses except for the Kelvin waves that account for only 25.2% of TC geneses. The number of each wave type-related TC genesis consistently varies seasonally with peak in the TC season (July-November), which is attributed to a combined effect of active wave probability and intensity change. The interannual variation in the TC genesis is well reproduced by the tropical wave-related TC genesis, especially in the region east of 150°E. An eastward extension of the enhanced monsoon trough coincides with increased tropical wave activity by accelerated wave-mean flow interaction.

The First Year of Solar-Wind Data From the GENESIS Mission

NASA Astrophysics Data System (ADS)

Wiens, R. C.; Barraclough, B. L.; Steinberg, J. T.; Reisenfeld, D. B.; Neugebauer, M.; Burnett, D. S.

2002-12-01

The GENESIS mission was launched in August, 2001, and has been in an L1 halo orbit for over a year. The primary purpose of the mission is to collect solar-wind samples that will be returned to Earth in 2004 for high-precision isotopic and elemental analyses. GENESIS uses conventional ion and electron spectrometers to record solar-wind conditions during collection, and to make real-time determinations of the solar-wind regimes to facilitate collection of separate samples of interstream (IS), coronal hole (CH), and coronal mass ejection (CME) flows. Of particular interest is the use of a bi-directional electron (BDE) index to determine the presence of CMEs. And although GENESIS lacks a magnetometer, the field vector, with sign ambiguity, is determined by the electron direction, and matches other spacecraft magnetometer data well. GENESIS in-situ data and on-board regime determinations are available on the web. The data from Fall, 2001 were characterized by numerous CME regimes (comprising 32% of the time in the 4th quarter, based on the on-board algorithm), with little CH flow (only 2%). A strong CH flow was observed every solar rotation from mid-January through late May. June was quiet, nearly all IS flow. The first and second quarters of 2002 were approximately 28% CME flow, with CH flow dropping from 18% to 6%. The discovery of unexpectedly noticeable BDE signals during CH flows at 1 AU (Steinberg et al., 2002) caused us early on to modify our regime selection algorithm to accommodate these. The on-board algorithm intentionally errs on the side of overestimating CME flows in order to keep the CH sample more pure. Comparisons have been made of various compositional parameters determined by Genesis (Barraclough et al., this meeting) and by ACE SWICS (Reisenfeld et al., this meeting) for times corresponding to the Genesis collection periods for each of the three regimes. The Genesis L1 halo orbit is ~0.8 x 0.25 million km radius, somewhat larger than the ~0.3 x 0

Analyzing the influences of two types of El Niño on tropical cyclone genesis with a modified genesis potential index

NASA Astrophysics Data System (ADS)

Yang, Yuxing; Yang, Lei; Wang, Faming

2017-03-01

To understand the impacts of large-scale circulation during the evolution of El Niño cycle on tropical cyclones (TC) is important and useful for TC forecast. Based on best-track data from the Joint Typhoon Warning Center and reanalysis data from National Centers for Environmental Prediction for the period 1975-2014, we investigated the influences of two types of El Niño, the eastern Pacific El Niño (EP-El Niño) and central Pacific El Niño (CP-El Niño), on global TC genesis. We also examined how various environmental factors contribute to these influences using a modified genesis potential index (MGPI). The composites reproduced for two types of El Niño, from their developing to decaying phases, were able to qualitatively replicate observed cyclogenesis in several basins except for the Arabian Sea. Certain factors of MGPI with more influence than others in various regions are identified. Over the western North Pacific, five variables were all important in the two El Niño types during developing summer (July-August-September) and fall (October-November-December), and decaying spring (April-May-June) and summer. In the eastern Pacific, vertical shear and relative vorticity are the crucial factors for the two types of El Niño during developing and decaying summers. In the Atlantic, vertical shear, potential intensity and relative humidity are important for the opposite variation of EP- and CP-El Niños during decaying summers. In the Southern Hemisphere, the five variables have varying contributions to TC genesis variation during peak season (January-February-March) for the two types of El Niño. In the Bay of Bengal, relative vorticity, humidity and omega may be responsible for clearly reduced TC genesis during developing fall for the two types and slightly suppressed TC cyclogenesis during EP-El Niño decaying spring. In the Arabian Sea, the EP-El Niño generates a slightly positive anomaly of TC genesis during developing falls and decaying springs, but the

Learning Activities for an Undergraduate Mineralogy/Petrology Course-"I Am/We Are."

ERIC Educational Resources Information Center

Goodell, Philip C.

2001-01-01

Introduces an entry level mineralogy/igneous petrology course designed for undergraduate students and presents a series of learning activities based on individual and cooperative learning. Includes 18 references. (Author/YDS)

Learning Mathematics in a CAS Environment: The Genesis of a Reflection about Instrumentation and the Dialectics between Technical and Conceptual Work.

ERIC Educational Resources Information Center

Artigue, Michele

2002-01-01

Presents an anthropological approach used in French research and the theory of instrumentation developed in cognitive ergonomics. Shows how these frameworks allow an approach to the educational use of CAS technology, focusing on the unexpected complexity of instrumental genesis, mathematical needs of instrumentation, status of instrumented…

Python as a federation tool for GENESIS 3.0.

PubMed

Cornelis, Hugo; Rodriguez, Armando L; Coop, Allan D; Bower, James M

2012-01-01

The GENESIS simulation platform was one of the first broad-scale modeling systems in computational biology to encourage modelers to develop and share model features and components. Supported by a large developer community, it participated in innovative simulator technologies such as benchmarking, parallelization, and declarative model specification and was the first neural simulator to define bindings for the Python scripting language. An important feature of the latest version of GENESIS is that it decomposes into self-contained software components complying with the Computational Biology Initiative federated software architecture. This architecture allows separate scripting bindings to be defined for different necessary components of the simulator, e.g., the mathematical solvers and graphical user interface. Python is a scripting language that provides rich sets of freely available open source libraries. With clean dynamic object-oriented designs, they produce highly readable code and are widely employed in specialized areas of software component integration. We employ a simplified wrapper and interface generator to examine an application programming interface and make it available to a given scripting language. This allows independent software components to be 'glued' together and connected to external libraries and applications from user-defined Python or Perl scripts. We illustrate our approach with three examples of Python scripting. (1) Generate and run a simple single-compartment model neuron connected to a stand-alone mathematical solver. (2) Interface a mathematical solver with GENESIS 3.0 to explore a neuron morphology from either an interactive command-line or graphical user interface. (3) Apply scripting bindings to connect the GENESIS 3.0 simulator to external graphical libraries and an open source three dimensional content creation suite that supports visualization of models based on electron microscopy and their conversion to computational models

Python as a Federation Tool for GENESIS 3.0

PubMed Central

Cornelis, Hugo; Rodriguez, Armando L.; Coop, Allan D.; Bower, James M.

2012-01-01

The GENESIS simulation platform was one of the first broad-scale modeling systems in computational biology to encourage modelers to develop and share model features and components. Supported by a large developer community, it participated in innovative simulator technologies such as benchmarking, parallelization, and declarative model specification and was the first neural simulator to define bindings for the Python scripting language. An important feature of the latest version of GENESIS is that it decomposes into self-contained software components complying with the Computational Biology Initiative federated software architecture. This architecture allows separate scripting bindings to be defined for different necessary components of the simulator, e.g., the mathematical solvers and graphical user interface. Python is a scripting language that provides rich sets of freely available open source libraries. With clean dynamic object-oriented designs, they produce highly readable code and are widely employed in specialized areas of software component integration. We employ a simplified wrapper and interface generator to examine an application programming interface and make it available to a given scripting language. This allows independent software components to be ‘glued’ together and connected to external libraries and applications from user-defined Python or Perl scripts. We illustrate our approach with three examples of Python scripting. (1) Generate and run a simple single-compartment model neuron connected to a stand-alone mathematical solver. (2) Interface a mathematical solver with GENESIS 3.0 to explore a neuron morphology from either an interactive command-line or graphical user interface. (3) Apply scripting bindings to connect the GENESIS 3.0 simulator to external graphical libraries and an open source three dimensional content creation suite that supports visualization of models based on electron microscopy and their conversion to computational

The Run-up to Volcanic Eruption Unveiled by Forensic Petrology and Geophysical Observations

NASA Astrophysics Data System (ADS)

Rasmussen, D. J.; Plank, T. A.; Roman, D. C.

2017-12-01

Volcanoes often warn of impending eruptions. However, one of the greatest challenges in volcano research is translating precursory geophysical signals into physical magmatic processes. Petrology offers powerful tools to study eruption run-up that benefit from direct response to magmatic forcings. Developing these tools, and tying them to geophysical observations, will help us identify eruption triggers (e.g., magmatic recharge, gas build-up, tectonic events) and understand the significance of monitored signals of unrest. We present an overview of petrologic tools used for studying eruption run-up, highlighting results from our study of the 1999 eruption of Shishaldin volcano. Olivine crystals contain chemical gradients, the consequence of diffusion following magma mixing events, which is modeled to determine mixing timescales. Modeled timescales provide strong evidence for at least three mixing events, which were triggered by magmatic recharge. Petrologic barometers indicate these events occurred at very shallow depths (within the volcanic edifice). The first mixing event occurred nine months before eruption, which was signaled by a swarm of deep-long period earthquake. Minor recharge events followed over two months, which are indicated by a second deep-long period earthquake swarm and a change in the local stress orientation measured by shear-wave splitting. Following these events, the system was relatively quiet until a large mixing event occurred 45 days prior to eruption, which was heralded by a large earthquake (M5.2). Following this event, geophysical signals of unrest intensified and became continuous. The final mixing event, beginning roughly a week before eruption, represents the final perturbation to the system before eruption. Our findings point to a relatively long run-up, which was subtle at first and intensified several weeks before eruption. This study highlights the strong link between geophysical signals of volcanic unrest and magmatic events, and

Dividing the Concentrator Target From the Genesis Mission

NASA Technical Reports Server (NTRS)

Lauer, H. V., Jr.; Burkett, P. J.; Clemett, S. J.; Gonzales, C. P.; Nakamura-Messenger, K.; Rodriquez, M. C.; See, T. H.; Sutter, B.

2014-01-01

The Genesis spacecraft, launched in 2001, traveled to a Lagrangian point between the Earth and Sun to collect particles from the solar wind and return them to Earth. However, during the return of the spacecraft in 2004, the parachute failed to open during descent, and the Genesis spacecraft crashed into the Utah desert. Many of the solar wind collectors were broken into smaller pieces, and the field team rapidly collected the capsule and collector pieces for later assessment. On each of the next few days, the team discovered that various collectors had survived intact, including three of four concentrator targets. Within a month, the team had imaged more than 10,000 fragments and packed them for transport to the Astromaterials Acquisition and Curation Office within the ARES Directorate at JSC. Currently, the Genesis samples are curated along with the other extraterrestrial sample collections within ARES. Although they were broken and dirty, the Genesis solar wind collectors still offered the science community the opportunity to better understand our Sun and the solar system as a whole. One of the more highly prized concentrator collectors survived the crash almost completely intact. The Genesis Concentrator was designed to concentrate the solar wind by a factor of at least 20 so that solar oxygen and nitrogen isotopes could be measured. One of these materials was the Diamond-on-Silicon (DoS) concentrator target. Unfortunately, the DoS concentrator broke on impact. Nevertheless, the scientific value of the DoS concentrator target was high. The Genesis Allocation Committee received a request for approximately 1 cm(sup 2) of the DoS specimen taken near the focal point of the concentrator for the analysis of solar wind nitrogen isotopes. The largest fragment, Genesis sample 60000, was designated for this allocation and needed to be precisely cut. The requirement was to subdivide the designated sample in a manner that prevented contamination of the sample and minimized

Determining relevant parameters for a statistical tropical cyclone genesis tool based upon global model output

NASA Astrophysics Data System (ADS)

Halperin, D.; Hart, R. E.; Fuelberg, H. E.; Cossuth, J.

2013-12-01

Predicting tropical cyclone (TC) genesis has been a vexing problem for forecasters. While the literature describes environmental conditions which are necessary for TC genesis, predicting if and when a specific disturbance will organize and become a TC remains a challenge. As recently as 5-10 years ago, global models possessed little if any skill in forecasting TC genesis. However, due to increased resolution and more advanced model parameterizations, we have reached the point where global models can provide useful TC genesis guidance to operational forecasters. A recent study evaluated five global models' ability to predict TC genesis out to four days over the North Atlantic basin (Halperin et al. 2013). The results indicate that the models are indeed able to capture the genesis time and location correctly a fair percentage of the time. The study also uncovered model biases. For example, probability of detection and false alarm rate varies spatially within the basin. Also, as expected, the models' performance decreases with increasing lead time. In order to explain these and other biases, it is useful to analyze the model-indicated genesis events further to determine whether or not there are systematic differences between successful forecasts (hits), false alarms, and miss events. This study will examine composites of a number of physically-relevant environmental parameters (e.g., magnitude of vertical wind shear, aerially averaged mid-level relative humidity) and disturbance-based parameters (e.g., 925 hPa maximum wind speed, vertical alignment of relative vorticity) among each TC genesis event classification (i.e., hit, false alarm, miss). We will use standard statistical tests (e.g., Student's t test, Mann-Whitney-U Test) to calculate whether or not any differences are statistically significant. We also plan to discuss how these composite results apply to a few illustrative case studies. The results may help determine which aspects of the forecast are (in

Numerical modeling and analysis of the effect of Greek complex topography on tornado genesis

NASA Astrophysics Data System (ADS)

Matsangouras, I. T.; Pytharoulis, I.; Nastos, P. T.

2014-02-01

Tornadoes have been reported in Greece over the last decades in specific sub-geographical areas and have been associated with strong synoptic forcing. It is well known that meteorological conditions over Greece are affected at various scales by the significant variability of topography, the Ionian Sea at the west and the Aegean Sea at the east. However, there is still uncertainty regarding topography's importance on tornadic generation and development. The aim of this study is to investigate the role of topography in significant tornado genesis events that were triggered under strong synoptic scale forcing over Greece. Three tornado events that occurred over the last years in Thiva (Boeotia, 17 November 2007), Vrastema (Chalkidiki, 12 February 2010) and Vlychos (Lefkada, 20 September 2011) have been selected for numerical experiments. These events were associated with synoptic scale forcing, while their intensity was T4-T5 (Torro scale) and caused significant damage. The simulations were performed using the non-hydrostatic Weather Research and Forecasting model (WRF), initialized with ECMWF gridded analyses, with telescoping nested grids that allow the representation of atmospheric circulations ranging from the synoptic scale down to the meso scale. In the experiments the topography of the inner grid was modified by: (a) 0% (actual topography) and (b) -100% (without topography). The aim was to determine whether the occurrence of tornadoes - mainly identified by various severe weather instability indices - could be indicated by modifying topography. The main utilized instability variables concerned the Bulk Richardson number shear (BRN), the energy helicity index (EHI), the storm-relative environmental helicity (SRH) and the maximum convective available potential energy (MCAPE, for parcel with maximum theta-e). Additional a verification of model was conducted for every sensitivity experiment accompanied with analysis absolute vorticity budget. Numerical simulations

Petrologic and oxygen isotopic study of ALH 85085-like chondrites

NASA Astrophysics Data System (ADS)

Prinz, M.; Weisberg, M. K.; Clayton, R. N.; Mayeda, T. K.; Ebihara, M.

1994-07-01

Four meteorites (PAT 91546, PCA 91328, PCA 91452, PCA 91467) petrologically similar to ALH 85085 chondrite have now been found. Previous studies of ALH 85085 showed it be a new kind of CR-related microchondrule-bearing chondrite, although one called it a sub-chondrite. The purpose of this study is to learn more about ALH 85085-like meteorites and their relationship to CR and CR-related (LEW 85332, Acfer 182, Bencubbin) chondrites. The methods used included petrology, INA bulk chemical analysis (PAT 91546, PCA 91467), and O isotopic analyses of the whole rocks and separated chondrules and dark inclusions (DIs) from PAT 91546. Since microchondrules and fragments are approximately 20 microns it was necessary to analyze composite samples for O; one was of approximately 100 chondrules, and another was of 5 DIs. Petrologically, the four meteorites are similar to ALH 85085, and there is no basis for determining if all of them, or any combinations, are paired. Mineralogically, olivine and pyroxene are highly magnesian FeNi metal generally has 3-10% Ni, and has a positive Ni-Co correlation similar to that in CR and CR-related chondrites. Refractory inclusions are similar in size to the chondrules and have the following assemblages: (1) hibonite-perovskite, (2) melilite-fassaite-forsterite, (3) grossite (Ca-dialuminate)-melilite-perovskite, (4) spinel-melilite, and (5) spinel-pyroxene aggregates. Chemically, INA analyses indicate that PAT 91546 and PCA 91467 are generally similar to ALH 85085. Oxygen isotopic analyses of the four whole-rock compositions fall along the CR mixing line as does ALH 85085; they are also close to LEW 85332, Acfer 182, and Bencubbin. This supports the concept that these are all CR-related chondrites. Even stronger support is found in the compositions of the chondrules and DIs in PAT 91546, which also plot on or near the CR line.

Petrology, geochemistry and zircon U-Pb geochronology of a layered igneous complex from Akarui Point in the Lützow-Holm Complex, East Antarctica: Implications for Antarctica-Sri Lanka correlation

NASA Astrophysics Data System (ADS)

Kazami, Sou; Tsunogae, Toshiaki; Santosh, M.; Tsutsumi, Yukiyasu; Takamura, Yusuke

2016-11-01

The Lützow-Holm Complex (LHC) of East Antarctica forms part of a complex subduction-collision orogen related to the amalgamation of the Neoproterozoic supercontinent Gondwana. Here we report new petrological, geochemical, and geochronological data from a metamorphosed and disrupted layered igneous complex from Akarui Point in the LHC which provide new insights into the evolution of the complex. The complex is composed of mafic orthogneiss (edenite/pargasite + plagioclase ± clinopyroxene ± orthopyroxene ± spinel ± sapphirine ± K-feldspar), meta-ultramafic rock (pargasite + olivine + spinel + orthopyroxene), and felsic orthogneiss (plagioclase + quartz + pargasite + biotite ± garnet). The rocks show obvious compositional layering reflecting the chemical variation possibly through magmatic differentiation. The metamorphic conditions of the rocks were estimated using hornblende-plagioclase geothermometry which yielded temperatures of 720-840 °C. The geochemical data of the orthogneisses indicate fractional crystallization possibly related to differentiation within a magma chamber. Most of the mafic-ultramafic samples show enrichment of LILE, negative Nb, Ta, P and Ti anomalies, and constant HFSE contents in primitive-mantle normalized trace element plots suggesting volcanic arc affinity probably related to subduction. The enrichment of LREE and flat HREE patterns in chondrite-normalized REE plot, with the Nb-Zr-Y, Y-La-Nb, and Th/Yb-Nb/Yb plots also suggest volcanic arc affinity. The felsic orthogneiss plotted on Nb/Zr-Zr diagram (low Nb/Zr ratio) and spider diagrams (enrichment of LILE, negative Nb, Ta, P and Ti anomalies) also show magmatic arc origin. The morphology, internal structure, and high Th/U ratio of zircon grains in felsic orthogneiss are consistent with magmatic origin for most of these grains. Zircon U-Pb analyses suggest Early Neoproterozoic (847.4 ± 8.0 Ma) magmatism and protolith formation. Some older grains (1026-882 Ma) are regarded as

Geochemistry of Martian Meteorites and the Petrologic Evolution of Mars

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.

2002-01-01

Mafic igneous rocks serve as probes of the interiors of their parent bodies - the compositions of the magmas contain an imprint of the source region composition and mineralogy, the melting and crystallization processes, and mixing and assimilation. Although complicated by their multifarious history, it is possible to constrain the petrologic evolution of an igneous province through compositional study of the rocks. Incompatible trace elements provide one means of doing this. I will use incompatible element ratios of martian meteorites to constrain the early petrologic evolution of Mars. Incompatible elements are strongly partitioned into the melt phase during igneous processes. The degree of incompatibility will differ depending on the mineral phases in equilibrium with the melt. Most martian meteorites contain some cumulus grains, but nevertheless, incompatible element ratios of bulk meteorites will be close to those of their parent magmas. ALH 84001 is an exception, and it will not be discussed. The martian meteorites will be considered in two groups; a 1.3 Ga group composed of the clinopyroxenites and dunite, and a younger group composed of all others.

Finding the Genesis for a Thesis

ERIC Educational Resources Information Center

Caroll, Joyce Armstrong

2013-01-01

This article describes a prewriting heuristics strategy that can help students find the genesis of their thesis. The 3 functions of the heuristic procedure are that it aids in retrieving relevant information stored in the mind; draws attention to important information that can be further researched or accessed; and prepares the mind for the…

Sample Return Missions Where Contamination Issues are Critical: Genesis Mission Approach

NASA Technical Reports Server (NTRS)

Allton, Judith H.; Stansbery E. K.

2011-01-01

The Genesis Mission, sought the challenging analytical goals of accurately and precisely measuring the elemental and isotopic composition of the Sun to levels useful for planetary science, requiring sensitivities of ppm to ppt in the outer 100 nm of collector materials. Analytical capabilities were further challenged when the hard landing in 2004 broke open the canister containing the super-clean collectors. Genesis illustrates that returned samples allow flexibility and creativity to recover from setbacks.

Apollo 12 feldspathic basalts 12031, 12038, and 12072; petrology, comparison and interpretations

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

Beaty, E.W.; Hill, S.M.R.; Albee, A.L.

1979-01-01

Modal and chemical data indicate that 12072, 12038, and 12031, the Apollo 12 feldspathic basalts, form a well-defined group which cannot be related to the other Apollo 12 rock types. 12072 contains phenocrysts of olivine and pigeonite and microphenocrysts of Cr-spinel set in a fine-grained, variolitic groundmass. 12038 is a medium-grained, equigranular basalt with a texture indicating it was multiply saturated. 12031 is a coarse-grained rock with granular to graphic intergrowths of pyroxene and plagioclase; it was also multiply saturated. Petrologic observations, as well as the bulk chemistry, are consistent with the interpretation that 12031 could be derived from 12072more » through fractionation of Cr-spinel, olivine, and pigeonite, the observed phenocryst assemblage. 12038, however, contains more pigeonite, less olivine, three times as much Ca-phosphate minerals, one-fifth as much troilite, and much more sodic plagioclase than 12072. These differences indicate that 12038 must have come from a separate igneous body. Consideration of the bulk compositions indicates that neither 12072 and 12031 nor 12038 could have been derived from the Apollo 12 olivine, pigeonite, or ilmenite basalts by crystal--liquid fractionation. The general petrologic similarities between 12072, 12031, and the other Apollo 12 basalts suggests that they were produced in either the same or similar source regions. 12038, however, is petrologically and chemically unique, and is probably exotic to the Apollo 12 landing site.« less

Carbon petrology in cometary dust

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1992-01-01

Chondritic porous (CP) interplanetary dust particles (IDP's) are collected in the Earth's stratosphere. There exists an extensive database on major and minor element chemistry, stable isotopes, noble gas abundances and mineralogy of many CP IDP's, as well as infrared and Raman spectroscopic properties. For details on the mineralogy, chemistry and physical properties of IDP's, I refer to the reviews by Mackinnon and Rietmeijer (1987), Bradley et al. (1988) and Sandford (1987). Texture, mineralogy (Mackinnon and Rietmeijer, 1987) and chemistry (Schramm et al., 1989; Flynn and Sutton, 1991) support the notion that CP IDP's are a unique group of ultrafine-grained extraterrestiral materials that are distinct from any known meteorite class. Their fluffy, or porous, morphology suggests that CP IDP's probably endured minimal alteration by protoplanetary processes since their formation. It is generally accepted that CP IDP's are solid debris from short-period comets. The evidence is mostly circumstantial but this notion gained significant support based on the comet Halley dust data (Brownlee, 1990). In this paper, I will accept that CP IDP's are indeed cometary dust. The C/Si ratio in CP IDP's is 3.3 times higher than in CI carbonaceous chondrites (Schramm et al. 1989). The intraparticle carbon distribution is heteorogeneous (Rietmeijer and McKay, 1986). Carbon occurs both in oxidized and reduced forms. Analytical electron microscope (AEM) and Raman spectroscopic analyses have shown the presence of several carbon forms in CP IDP's but the data are scattered in the literature. Carbons in cometary CP IDP's are among the most pristine Solar System carbons available for laboratory study. Similar to a recently developed petrological model for the diversity of layer silicates in CP IDP's (Zolensky, 1991) that is useful to constrain in situ aqueous alteration in comets (Rietmeijer and Mackinnon, 1987a), I here present the first effort to develop a petrological concept of carbons

Decrease of tropical cyclone genesis frequency in the western North Pacific since 1960s

NASA Astrophysics Data System (ADS)

Hu, Feng; Li, Tim; Liu, Jia; Bi, Mingyu; Peng, Melinda

2018-03-01

Tropical cyclone (TC) genesis frequency in the western North Pacific (WNP) during 1960-2014 shows a step-by-step decrease on interdecadal timescale, in accordance to the phase of the Interdecadal Pacific Oscillation (IPO). The environmental parameters responsible for the interdecadal change of TC genesis frequency were investigated. It was found that vertical wind shear especially the zonal wind shear plays a critical role, while other parameters such as sea surface temperature (SST), vertical velocity, divergence, humidity and maximum potential intensity cannot explain the step-by-step decrease of TC genesis frequency. A further diagnosis shows that the interdecadal change of vertical wind shear is caused by SST and associated rainfall pattern changes across the Indo-Pacific Ocean. A stronger warming in the Indian Ocean/western Pacific from 1960-1976 to 1977-1998 led to enhanced convection over the Maritime Continent and thus strengthened vertical shear over the key TC genesis region in the WNP. A La Nina-like SST pattern change from 1977-1998 to 1999-2014 led to a strengthened Walker circulation in the tropical Pacific, which further enhanced the vertical shear and decreased TC genesis frequency in the WNP.

Detailed Mineralogy and Petrology of Intermediate Martian Lherzolitic Shergottite Northwest Africa 6342

NASA Astrophysics Data System (ADS)

Kizovski, T. V.; Tait, K. T.

2017-07-01

NWA 6342 is a 35.5 g lherzolitic shergottite that was found in Algeria in 2010. The purpose of this work is to complete a detailed mineralogical, petrological, and geochemical analysis of NWA 6342 and compare it to other lherzolitic sherogottites.

Nuts and Bolts - Techniques for Genesis Sample Curation

NASA Technical Reports Server (NTRS)

Burkett, Patti J.; Rodriquez, M. C.; Allton, J. H.

2011-01-01

The Genesis curation staff at NASA Johnson Space Center provides samples and data for analysis to the scientific community, following allocation approval by the Genesis Oversight Committee, a sub-committee of CAPTEM (Curation Analysis Planning Team for Extraterrestrial Materials). We are often asked by investigators within the scientific community how we choose samples to best fit the requirements of the request. Here we will demonstrate our techniques for characterizing samples and satisfying allocation requests. Even with a systematic approach, every allocation is unique. We are also providing updated status of the cataloging and characterization of solar wind collectors as of January 2011. The collection consists of 3721 inventoried samples consisting of a single fragment, or multiple fragments containerized or pressed between post-it notes, jars or vials of various sizes.

The GENESIS Mission: Solar Wind Isotopic and Elemental Compositions and Their Implications

NASA Astrophysics Data System (ADS)

Wiens, R. C.; Burnett, D. S.; McKeegan, K. D.; Kallio, A. P.; Mao, P. H.; Heber, V. S.; Wieler, R.; Meshik, A.; Hohenberg, C. M.; Mabry, J. C.; Gilmour, J.; Crowther, S. A.; Reisenfeld, D. B.; Jurewicz, A.; Marty, B.; Pepin, R. O.; Barraclough, B. L.; Nordholt, J. E.; Olinger, C. T.; Steinberg, J. T.

2008-12-01

The GENESIS mission was a novel NASA experiment to collect solar wind at the Earth's L1 point for two years and return it for analysis. The capsule crashed upon re-entry in 2004, but many of the solar-wind collectors were recovered, including separate samples of coronal hole, interstream, and CME material. Laboratory analyses of these materials have allowed higher isotopic precision than possible with current in-situ detectors. To date GENESIS results have been obtained on isotopes of O, He, Ne, Ar, Kr, and Xe on the order of 1% accuracy and precision, with poorer uncertainty on Xe isotopes and significantly better uncertainties on the lighter noble gases. Elemental abundances are available for the above elements as well as Mg, Si, and Fe. When elemental abundances are compared with other in situ solar wind measurements, agreement is generally quite good. One exception is the Ne elemental abundance, which agrees with Ulysses and Apollo SWC results, but not with ACE. Neon is of particular interest because of the uncertainty in the solar Ne abundance, which has significant implications for the standard solar model. Helium isotopic results of material from the different solar wind regimes collected by GENESIS is consistent with isotopic fractionation predictions of the Coulomb drag model, suggesting that isotopic fractionation corrections need to be applied to heavier elements as well when extrapolating solar wind to solar compositions. Noble gas isotopic compositions from GENESIS are consistent with those obtained for solar wind trapped in lunar grains, but have for the first time yielded a very precise Ar isotopic result. Most interesting for cosmochemistry is a preliminary oxygen isotopic result from GENESIS which indicates a solar enrichment of ~4% in 16O relative to the planets, consistent with a photolytic self-shielding phenomenon during solar system formation. Analyses of solar wind N and C isotopes may further elucidate this phenomenon. Preliminary results

Slip rate and tremor genesis in Cascadia

USGS Publications Warehouse

Wech, Aaron G.; Bartlow, Noel M.

2014-01-01

At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

Genesis of Typhoon Nari (2001) from a mesoscale convective system

NASA Astrophysics Data System (ADS)

Zhang, Da-Lin; Tian, Liqing; Yang, Ming-Jen

2011-12-01

In this study, the origin and genesis of Typhoon Nari (2001) as well as its erratic looping track, are examined using large-scale analysis, satellite observations, and a 4 day nested, cloud-resolving simulation with the finest grid size of 1.33 km. Observational analysis reveals that Nari could be traced 5 days back to a diurnally varying mesoscale convective system with growing cyclonic vorticity and relative humidity in the lower troposphere and that it evolved from a mesoscale convective vortex (MCV) as moving over a warm ocean under the influence of a subtropical high, a weak westerly baroclinic disturbance, an approaching-and-departing Typhoon Danas to the east, and the Kuroshio Current. Results show that the model reproduces the genesis, final intensity, looping track, and the general convective activity of Nari during the 4 day period. It also captures two deep subvortices at the eye-eyewall interface that are similar to those previously observed, a few spiral rainbands, and a midget storm size associated with Nari's relatively dry and stable environment. We find that (1) continuous convective overturning within the MCV stretches the low-level vorticity and moistens a deep mesoscale column that are both favorable for genesis; (2) Nari's genesis does not occur until after the passage of the baroclinic disturbance; (3) convective asymmetry induces a smaller-sized vortex circulation from the preexisting MCV; (4) the vortex-vortex interaction with Danas leads to Nari's looping track and temporal weakening; and (5) midlevel convergence associated with the subtropical high and Danas accounts for the generation of a nearly upright eyewall.

Is the poleward migration of tropical cyclone maximum intensity associated with a poleward migration of tropical cyclone genesis?

NASA Astrophysics Data System (ADS)

Daloz, Anne Sophie; Camargo, Suzana J.

2018-01-01

A recent study showed that the global average latitude where tropical cyclones achieve their lifetime-maximum intensity has been migrating poleward at a rate of about one-half degree of latitude per decade over the last 30 years in each hemisphere. However, it does not answer a critical question: is the poleward migration of tropical cyclone lifetime-maximum intensity associated with a poleward migration of tropical cyclone genesis? In this study we will examine this question. First we analyze changes in the environmental variables associated with tropical cyclone genesis, namely entropy deficit, potential intensity, vertical wind shear, vorticity, skin temperature and specific humidity at 500 hPa in reanalysis datasets between 1980 and 2013. Then, a selection of these variables is combined into two tropical cyclone genesis indices that empirically relate tropical cyclone genesis to large-scale variables. We find a shift toward greater (smaller) average potential number of genesis at higher (lower) latitudes over most regions of the Pacific Ocean, which is consistent with a migration of tropical cyclone genesis towards higher latitudes. We then examine the global best track archive and find coherent and significant poleward shifts in mean genesis position over the Pacific Ocean basins.

GENESI-DR: Discovery, Access and on-Demand Processing in Federated Repositories

NASA Astrophysics Data System (ADS)

Cossu, Roberto; Pacini, Fabrizio; Parrini, Andrea; Santi, Eliana Li; Fusco, Luigi

2010-05-01

GENESI-DR (Ground European Network for Earth Science Interoperations - Digital Repositories) is a European Commission (EC)-funded project, kicked-off early 2008 lead by ESA; partners include Space Agencies (DLR, ASI, CNES), both space and no-space data providers such as ENEA (I), Infoterra (UK), K-SAT (N), NILU (N), JRC (EU) and industry as Elsag Datamat (I), CS (F) and TERRADUE (I). GENESI-DR intends to meet the challenge of facilitating "time to science" from different Earth Science disciplines in discovery, access and use (combining, integrating, processing, …) of historical and recent Earth-related data from space, airborne and in-situ sensors, which are archived in large distributed repositories. In fact, a common dedicated infrastructure such as the GENESI-DR one permits the Earth Science communities to derive objective information and to share knowledge in all environmental sensitive domains over a continuum of time and a variety of geographical scales so addressing urgent challenges such as Global Change. GENESI-DR federates data, information and knowledge for the management of our fragile planet in line with one of the major goals of the many international environmental programmes such as GMES, GEO/GEOSS. As of today, 12 different Digital Repositories hosting more than 60 heterogeneous dataset series are federated in GENESI-DR. Series include satellite data, in situ data, images acquired by airborne sensors, digital elevation models and model outputs. ESA has started providing access to: Category-1 data systematically available on Internet; level 3 data (e.g., GlobCover map, MERIS Global Vegetation Index); ASAR products available in ESA Virtual Archive and related to the Supersites initiatives. In all cases, existing data policies and security constraints are fully respected. GENESI-DR also gives access to Grid and Cloud computing resources allowing authorized users to run a number of different processing services on the available data. The GENESI

A genesis potential index for Western North Pacific tropical cyclones by using oceanic parameters

NASA Astrophysics Data System (ADS)

Zhang, Min; Zhou, Lei; Chen, Dake; Wang, Chunzai

2016-09-01

This study attempts to create a tropical cyclone (TC) genesis potential index (GPI) by considering oceanic parameters and necessary atmospheric parameters. Based on the general understanding of the oceanic impacts on TC genesis, many candidate factors are evaluated and discriminated, resulting in a new GPI index, which is referred to as GPIocean. GPIocean includes the parameters of (1) absolute vorticity at 1000 hPa, (2) net sea surface longwave radiation, (3) mean ocean temperature in the upper mixed layer, and (4) depth of the 26°C isotherm. GPIocean is comparable to existing GPIs in representing TC genesis over the western North Pacific on seasonal and interannual variations. The same procedure can be applied to create a similar GPI for the other ocean basins. In the context of climate change, this new index is expected to be useful for evaluating the oceanic influences on TC genesis by using ocean reanalysis products and climate model outputs.

The Genesis of tectonically and hydrothermally controlled industry mineral deposits: A geochemical and structural study

NASA Astrophysics Data System (ADS)

Wölfler, Anke; Prochaska, Walter; Henjes-Kunst, Friedhelm; Fritz, Harald

2010-05-01

The study aims to investigate the role of hydrothermal fluids in the formation of talc and magnesite deposits. These deposits occur in manifold geological and tectonical settings such as stockworks and veins within ultramafite hostrocks and monomineralic lenses within marine platform sediments. Along shear zones talc mineralizations may occur as a result of tectonical and hydrothermal activity. To understand the role of the fluids for the genesis of the mineralization, deposits in different geological and tectonical settings are investigated: Talc mineralization within in magnesite in low-grade palaeozoic nappe complexes (Gemerska Poloma, Slovakia): The magnesite body lies within the Gemer unit of the Inner Carpathians consisting of Middle Triassic metacarbonates and Upper Triassic pelagic limestones and radiolarites. The talc mineralization is bound to crosscutting veins. Two metamorphic events can be distinguished, one during Variscan orogeny and one related to the Alpine orogeny leading to the formation of talc along faults in an Mg carbonate body (Radvanec et al, 2004).The origin of the fluids as well as the tectonic events leading to the mineralization is still widely unknown. Talc mineralization in shearzones within Palaeozoic meta sedimentary rocks (Sa Matta, Sardinia): Variscan granitoids intruded Palaeozoic meta sedimentary rocks and were overprinted be NE striking tectonic structures that host talc mineralizations. The origin of Mg and fluids leading to the mineralization is still not answered satisfactorily (Grillo and Prochaska, 2007) and thus a tectonic model for the genesis of the talc deposit is missing. Talc mineralization within UHP pre-Alpine continental crust (Val Chisone, Italy): The talc deposit forms part of the Dora-Maira Massif. Geologicaly the massif derived from a Variscan basement that includes post-Variscan intrusions. The talc mineralization occurs as a sheetlike, conformable body. A possible tectonic emplacement of talc along shear

75 FR 69458 - Notice of Availability of the Record of Decision for the Genesis Solar Energy Project and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-12

..., LVRWB09B2520] Notice of Availability of the Record of Decision for the Genesis Solar Energy Project [email protected] . SUPPLEMENTARY INFORMATION: Genesis Solar, LLC, a wholly owned subsidiary of NextEra Energy Resources, filed right-of-way (ROW) application CACA-048880 for the proposed Genesis Solar Energy...

GENESI-DR - A single access point to Earth Science data

NASA Astrophysics Data System (ADS)

Cossu, R.; Goncalves, P.; Pacini, F.

2009-04-01

The amount of information being generated about our planet is increasing at an exponential rate, but it must be easily accessible in order to apply it to the global needs relating to the state of the Earth. Currently, information about the state of the Earth, relevant services, analysis results, applications and tools are accessible in a very scattered and uncoordinated way, often through individual initiatives from Earth Observation mission operators, scientific institutes dealing with ground measurements, service companies, data catalogues, etc. A dedicated infrastructure providing transparent access to all this will support Earth Science communities by allowing them to easily and quickly derive objective information and share knowledge based on all environmentally sensitive domains. The use of high-speed networks (GÉANT) and the experimentation of new technologies, like BitTorrent, will also contribute to better services for the Earth Science communities. GENESI-DR (Ground European Network for Earth Science Interoperations - Digital Repositories), an ESA-led, European Commission (EC)-funded two-year project, is taking the lead in providing reliable, easy, long-term access to Earth Science data via the Internet. This project will allow scientists from different Earth Science disciplines located across Europe to locate, access, combine and integrate historical and fresh Earth-related data from space, airborne and in-situ sensors archived in large distributed repositories. GENESI-DR builds a federated collection of heterogeneous digital Earth Science repositories to establish a dedicated infrastructure providing transparent access to all this and allowing Earth Science communities to easily and quickly derive objective information and share knowledge based on all environmentally sensitive domains. The federated digital repositories, seen as services and data providers, will share access to their resources (catalogue functions, data access, processing services etc

Genesis Solar-Wind Sample Return Mission: The Materials

NASA Technical Reports Server (NTRS)

Jurewicz, A. J. G.; Burnett, D. S.; Wiens, R. C.; Woolum, D.

2003-01-01

The Genesis spacecraft has two primary instruments which passively collect solar wind. The first is the collector arrays , a set of panels, each of which can deploy separately to sample the different kinds of solar wind (regimes). The second is the concentrator, an electrostatic mirror which will concentrate ions of mass 4 through mass 25 by about a factor of 20 by focusing them onto a 6 cm diameter target. When not deployed, these instruments fit into a compact canister. After a two year exposure time, the deployed instruments can be folded up, sealed into the canister, and returned to earth for laboratory analysis. Both the collector arrays and the concentrator will contain suites of ultra-high purity target materials, each of which is tailored to enable the analysis of a different family of elements. This abstract is meant to give a brief overview of the Genesis mission, insight into what materials were chosen for flight and why, as well as head s up information as to what will be available to planetary scientist for analysis when the solar-wind samples return to Earth in 2003. Earth. The elemental and isotopic abundances of the solar wind will be analyzed in state-of-the-art laboratories, and a portion of the sample will be archived for the use of future generations of planetary scientists. Technical information about the mission can be found at www.gps.caltech.edu/genesis.

Simulation of the Genesis of Hurricane Javier (2004) in the Eastern Pacific

NASA Technical Reports Server (NTRS)

Braun, Scott

2005-01-01

NASA is preparing for the Tropical Cloud Systems and Processes (TCSP) field experiment in July 2005, a joint effort with NOAA to study tropical cloud systems and tropical cyclone genesis in the Eastern Pacific. A major thrust of the TCSP program is the improvement of the understanding and prediction of tropical cyclone genesis, intensity, motion, rainfall potential, and landfall impacts using remote sensing and in-situ data, as well as numerical modeling, particularly as they relate to the three phases of water. The Eastern Pacific has the highest frequency of genesis events per unit area of any region worldwide. African easterly waves, mesoscale convective systems (MCSs), and orographic effects are thought to play roles in the genesis of tropical cyclones there. The general consensus is that tropical depressions form in association with one or more mid-level, mesoscale cyclonic vortices that are generated within the stratiform region of the MCS precursors. To create the warm core tropical depression vortex, however, the midlevel cyclonic circulation must somehow extend down to the surface and the tangential winds must attain sufficient strength (-10 m s- ) to enable the wind-induced surface heat exchange to increase the potential energy of the boundary layer air.

The Genesis Mission: Contamination Control and Curation

NASA Technical Reports Server (NTRS)

Stansbery, E. K.

2002-01-01

The Genesis mission, launched in August 2001, is collecting samples of the solar wind and will return to Earth in 2004. Genesis can be viewed as the most fundamental of NASA's sample return missions because it is expected to provide insight into the initial elemental and isotopic composition of the solar nebula from which all other planetary objects formed. The data from this mission will have a large impact on understanding the origins and diversity of planetary materials. The collectors consist of clean, pure materials into which the solar wind will imbed. Science and engineering issues such as bulk purity, cleanliness, retention of solar wind, and ability to withstand launch and entry drove material choices. Most of the collector materials are installed on array frames that are deployed from a clean science canister. Two of the arrays are continuously exposed for collecting the bulk solar wind; the other three are only exposed during specific solar wind regimes as measured by ion and electron monitors. Other materials are housed as targets at the focal point of an electrostatic mirror, or "concentrator", designed to enhance the flux of specific solar wind species. Johnson Space Center (JSC) has two principal responsibilities for the Genesis mission: contamination control and curation. Precise and accurate measurements of the composition of the solar atoms require that the collector materials be extremely clean and well characterized before launch and during the mission. Early involvement of JSC curation personnel in concept development resulted in a mission designed to minimize contaminants from the spacecraft and operations. A major goal of the Genesis mission is to provide a reservoir of materials for the 21 51 century. When the collector materials are returned to Earth, they must be handled in a clean manner and their condition well documented. Information gained in preliminary examination of the arrays and detailed surveys of each collector will be used to

Teaching Igneous and Metamorphic Petrology Through Guided Inquiry Projects

NASA Astrophysics Data System (ADS)

McMillan, N. J.

2003-12-01

Undergraduate Petrology at New Mexico State University (GEOL 399) has been taught using three, 5-6 week long projects in place of lectures, lab, and exams for the last six years. Reasons for changing from the traditional format include: 1) to move the focus from identification and memorization to petrologic thinking; 2) the need for undergraduate students to apply basic chemical, structural, and field concepts to igneous and metamorphic rocks; 3) student boredom in the traditional mode by the topic that has captivated my professional life, in spite of my best efforts to offer thrilling lectures, problems, and labs. The course has three guided inquiry projects: volcanic, plutonic, and pelitic dynamothermal. Two of the rock suites are investigated during field trips. Each project provides hand samples and thin sections; the igneous projects also include whole-rock major and trace element data. Students write a scientific paper that classifies and describes the rocks, describes the data (mineralogical and geochemical), and uses data to interpret parameters such as tectonic setting, igneous processes, relationship to phase diagrams, geologic history, metamorphic grade, metamorphic facies, and polymetamorphic history. Students use the text as a major resource for self-learning; mini-lectures on pertinent topics are presented when needed by the majority of students. Project scores include evaluation of small parts of the paper due each Friday and participation in peer review as well as the final report. I have found that petrology is much more fun, although more difficult, to teach using this method. It is challenging to be totally prepared for class because students are working at different speeds on different levels on different aspects of the project. Students enjoy the course, especially the opportunity to engage in scientific investigation and debate. A significant flaw in this course is that students see fewer rocks and have less experience in rock classification

Petrologic model of the northern Mississippi Embayment based on satellite magnetic and ground-based geophysical data

NASA Technical Reports Server (NTRS)

Thomas, H. H.

1984-01-01

A petrologic model of the northern Mississippi Embayment, derived from gravity, seismic and rift data, is evaluated by converting the model to a magnetization model which is compared with satellite magnetic anomaly models. A magnetization contrast of approximately -0.54 A/m, determined from the petrologic model of the embayment compares favorably to values of -0.62 A/m and -0.45 A/m from a Magsat United States Apparent Magnetization Contrast Map and a published POGO magnetization contrast model, respectively. The petrologic model suggests that the magnetic anomaly low associated with the Mississippi Embayment may be largely due to the intrusion under non-oxidizing conditions of low Curie temperature gabbroic material at the base of the crust of the embayment. Near-surface mafic plutons, bordering the Mississippi Valley Graben, appear from aeromagnetic data to have higher magnetizations than the deeper gabbroic material; however, it is impossible to ascertain if this is due to compositional differences or similar material at shallower (lower temperature) depths. These results indicate that variations in the Curie temperatures of intrusions accompanying rifting may account for a large part of the wide range of magnetic anomalies associated with presently inactive rifts with normal heat flow.

Geochemistry and genesis of the angrites

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

Mittlefehldt, D.W.; Lindstrom, M.M.

1990-11-01

The angrites Angra dos Reis, LEW86010, and LEW87051 are petrologically and compositionally similar achondrites. All angrites have high FeO/MnO ratios of 80-94 and very low CI normalized Na/Sm ratios of 0.001-0.003. High abundances of oxidized Fe and low abundances of moderately volatile Na most likely resulted from parent body processes, such as magmatic outgassing, rather than nebular processes. All angrites have fractionated Ca/Al ratios, with Angra dos Reis exhibiting the most extreme ratio (3.1 {times} CI). For Angra dos Reis, cumulus material may be the cause of the high Ca/Al ratio. Refractory element abundances of LEW86010 and LEW87051 show similarmore » patterns, while Angra dos Reis has both greater enrichments in these elements and more fractionated patterns. Compositional and petrologic constraints indicate that LEW86010 and LEW87051 are related via olivine control. The refractory element abundances and mg{number sign} of LEW86010 can be approximated by removal of olivine from LEW87051, suggesting that LEW86010 may be a residual melt from a LEW87051-like precursor. Alternatively, LEW87051 may have formed via olivine accumulation from a LEW86010-like precursor. The differences between the LEW86010-LEW87051 duo and Angra dos Reis suggest that either the angrite parent body was heterogeneous or that Angra dos Reis was formed on a separate parent body. Based on FeO/MnO ratios and normative mineralogies, the angrite parent body(ies) may be similar in bulk composition to one of the carbonaceous chondrite groups, particularly CI-CM-CO.« less

The petrology and petrogenesis of the Swaldale region, Motzfeldt Center, South Greenland

NASA Astrophysics Data System (ADS)

Reekie, Callum; Finch, Adrian

2016-04-01

Motzfeldt is one of several high-level alkaline plutonic centers that collectively define the mid-Proterozoic Gardar Province of South Greenland. Despite pyrochlore-hosted Ta-enrichment (± Nb-Zr-REE), the petrology, geochemistry and petrogenesis across the center remain to be fully constrained. We present petrological and geochemical data for the Swaldale region, an arcuate band of nepheline syenite and associated intrusives on Motzfeldt's NW margin. Work for this present study was undertaken in collaboration with the license holder, Regency Mines plc. Swaldale comprises two geochemically distinct magmatic members. The largest, the Motzfeldt Sø Formation (MSF; EuN/Eu*N = 0.35), is a suite of diverse syenite variants that show significant petrological and geochemical heterogeneity. These rocks have a relatively restricted SiO2 range (57.4-62.9 wt.%) with concurrent variation in (Na+K)/Al (0.75-0.95), Mg/(Mg+Fe) (2.18-19.82) and ΣREE (595.0-3095.9 ppm), emphasizing their evolved but not peralkaline nature. Fractionation is mirrored by pyroxene geochemistry with evolution from aegirine-augite, aegirine-hedenbergite, to aegirine. Accessory pyrochlore, titanite, and zircon are rare; however, anomalous facies of zircon-rich (~2 wt.%) syenite are observed. Intercumulus fluorite is a common accessory within MSF rocks. Hydrothermal alteration, marked by hematized alkali-feldspar, is pervasive and ubiquitous. Further peraluminous syenite of the Geologfjeld Formation ((Na+K)/Al = 0.74; EuN/Eu*N = 1.60) marks the truncated remnant of an early syenite stock to the north of the MSF. These rocks contain salite, which, in addition to a lower ΣREE and higher Mg/(Mg+Fe) (18.01), demonstrates the less-fractionated nature of this stock in comparison with the MSF. Sheeted intrusions of peralkaline syenite ((Na+K)/Al = 1.1; Ta = 32.4 ppm) truncate the MSF across central Swaldale. On a mineralogical basis, it is hypothesized that such intrusions reflect outward sheeting of the

Mineralogy, petrology and geochemistry of carbonaceous chondritic clasts in the LEW 85300 polymict eucrite

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Hewins, R. H.; Mittlefehldt, D. W.; Lindstrom, M. M.; Xiao, X.; Lipschutz, M. E.

1992-01-01

We have performed a detailed petrologic and mineralogic study of two chondritic clasts from the polymict eucrite Lewis Cliff (LEW) 85300, and performed chemical analyses by INAA and RNAA on one of these. Petrologically, the clasts are identified and are composed of dispersed aggregates, chondrules, and chondrule fragments supported by matrix. The aggregates and chondrules are composed of olivine, orthopyroxene, plus some diopside. The matrix consists of fine-grained olivine, and lesser orthopyroxene and augite. Fine-grained saponite is common in the matrix. The bulk major composition of the clast studied by INAA and RNAA shows unusual abundance patterns for lithophile, siderophile and chalcophile elements but is basically chondritic. The INAA/RNAA data preclude assignment of the LEW 85300,15 clast to any commonly accepted group of carbonaceous chondrite.

Interactive Storytelling: From the Book of Genesis

ERIC Educational Resources Information Center

Park, Keith

2004-01-01

Keith Park, advisory teacher for Sense (the National Deafblind Rubella Association) in Greenwich and Lewisham, London, has written about his approach to interactive storytelling for BJSE before. This article describes a series of poetry workshops based on chapters 37 to 45 of the Book of Genesis (the story of Joseph and his family) using the text…

Apollo 14 Lunar glass fragment known as Genesis bean

NASA Technical Reports Server (NTRS)

1972-01-01

A tiny green glass fragment taken from an Apollo 14 core tube sampling. Because of its scientific significance and shape, the fragment has been nicknamed the 'Genesis bean'. The main constituents are iron and magnesium.

Genesis Silicon Carbide Concentrator Target 60003 Preliminary Ellipsometry Mapping Results

NASA Technical Reports Server (NTRS)

Calaway, M. J.; Rodriquez, M. C.; Stansbery, E. K.

2007-01-01

The Genesis concentrator was custom designed to focus solar wind ions primarily for terrestrial isotopic analysis of O-17/O-16 and O-18/O-16 to +/-1%, N-15/N-14 to +/-1%, and secondarily to conduct elemental and isotopic analysis of Li, Be, and B. The circular 6.2 cm diameter concentrator target holder was comprised of four quadrants of highly pure semiconductor materials that included one amorphous diamond-like carbon, one C-13 diamond, and two silicon carbide (SiC). The amorphous diamond-like carbon quadrant was fractured upon impact at Utah Test and Training Range (UTTR), but the remaining three quadrants survived fully intact and all four quadrants hold an important collection of solar wind. The quadrants were removed from the target holder at NASA Johnso n Space Center Genesis Curation Laboratory in April 2005, and have been housed in stainless steel containers under continual nitrogen purge since time of disintegration. In preparation for allocation of a silicon carbide target for oxygen isotope analyses at UCLA, the two SiC targets were photographed for preliminary inspection of macro particle contamination from the hard non-nominal landing as well as characterized by spectroscopic ellipsometry to evaluate thin film contamination. This report is focused on Genesis SiC target sample number 60003.

Semantically Enabling Knowledge Representation of Metamorphic Petrology Data

NASA Astrophysics Data System (ADS)

West, P.; Fox, P. A.; Spear, F. S.; Adali, S.; Nguyen, C.; Hallett, B. W.; Horkley, L. K.

2012-12-01

More and more metamorphic petrology data is being collected around the world, and is now being organized together into different virtual data portals by means of virtual organizations. For example, there is the virtual data portal Petrological Database (PetDB, http://www.petdb.org) of the Ocean Floor that is organizing scientific information about geochemical data of ocean floor igneous and metamorphic rocks; and also The Metamorphic Petrology Database (MetPetDB, http://metpetdb.rpi.edu) that is being created by a global community of metamorphic petrologists in collaboration with software engineers and data managers at Rensselaer Polytechnic Institute. The current focus is to provide the ability for scientists and researchers to register their data and search the databases for information regarding sample collections. What we present here is the next step in evolution of the MetPetDB portal, utilizing semantically enabled features such as discovery, data casting, faceted search, knowledge representation, and linked data as well as organizing information about the community and collaboration within the virtual community itself. We take the information that is currently represented in a relational database and make it available through web services, SPARQL endpoints, semantic and triple-stores where inferencing is enabled. We will be leveraging research that has taken place in virtual observatories, such as the Virtual Solar Terrestrial Observatory (VSTO) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO); vocabulary work done in various communities such as Observations and Measurements (ISO 19156), FOAF (Friend of a Friend), Bibo (Bibliography Ontology), and domain specific ontologies; enabling provenance traces of samples and subsamples using the different provenance ontologies; and providing the much needed linking of data from the various research organizations into a common, collaborative virtual observatory. In addition to better

[Use of antiseptic dekasan in complex treatment of peritonitis].

PubMed

Nazirov, F N; Aripova, N U; Makhkamova, M N; Dzhamalov, S I; Pulatov, M M; Magzumov, I Kh; Isroilov, B N

2014-01-01

Experience in treatment of 91 patients with peritonitis on various genesis using antiseptic Dekasan are presented. A marked clinical efficacy compared with that of other antiseptics in the complex treatment of peritonitis was noted.

Grants: Genesis of Some Funded Proposal Ideas

ERIC Educational Resources Information Center

Pazdar, John

2011-01-01

While "thinking outside the box" can be an over-used phase at times, in the world of grants it can provide the genesis of ideas. The "box" is the world of academia accepted by most educators, while "thinking outside" is the process that leads to grant ideas. In the grant world, "thinking outside the box" is a process of doing something that has…

Towards a Statistical Model of Tropical Cyclone Genesis

NASA Astrophysics Data System (ADS)

Fernandez, A.; Kashinath, K.; McAuliffe, J.; Prabhat, M.; Stark, P. B.; Wehner, M. F.

2017-12-01

Tropical Cyclones (TCs) are important extreme weather phenomena that have a strong impact on humans. TC forecasts are largely based on global numerical models that produce TC-like features. Aspects of Tropical Cyclones such as their formation/genesis, evolution, intensification and dissipation over land are important and challenging problems in climate science. This study investigates the environmental conditions associated with Tropical Cyclone Genesis (TCG) by testing how accurately a statistical model can predict TCG in the CAM5.1 climate model. TCG events are defined using TECA software @inproceedings{Prabhat2015teca, title={TECA: Petascale Pattern Recognition for Climate Science}, author={Prabhat and Byna, Surendra and Vishwanath, Venkatram and Dart, Eli and Wehner, Michael and Collins, William D}, booktitle={Computer Analysis of Images and Patterns}, pages={426-436}, year={2015}, organization={Springer}} to extract TC trajectories from CAM5.1. L1-regularized logistic regression (L1LR) is applied to the CAM5.1 output. The predictions have nearly perfect accuracy for data not associated with TC tracks and high accuracy differentiating between high vorticity and low vorticity systems. The model's active variables largely correspond to current hypotheses about important factors for TCG, such as wind field patterns and local pressure minima, and suggests new routes for investigation. Furthermore, our model's predictions of TC activity are competitive with the output of an instantaneous version of Emanuel and Nolan's Genesis Potential Index (GPI) @inproceedings{eman04, title = "Tropical cyclone activity and the global climate system", author = "Kerry Emanuel and Nolan, {David S.}", year = "2004", pages = "240-241", booktitle = "26th Conference on Hurricanes and Tropical Meteorology"}.

A Magnetic Petrology Database for Satellite Magnetic Anomaly Interpretations

NASA Astrophysics Data System (ADS)

Nazarova, K.; Wasilewski, P.; Didenko, A.; Genshaft, Y.; Pashkevich, I.

2002-05-01

A Magnetic Petrology Database (MPDB) is now being compiled at NASA/Goddard Space Flight Center in cooperation with Russian and Ukrainian Institutions. The purpose of this database is to provide the geomagnetic community with a comprehensive and user-friendly method of accessing magnetic petrology data via Internet for more realistic interpretation of satellite magnetic anomalies. Magnetic Petrology Data had been accumulated in NASA/Goddard Space Flight Center, United Institute of Physics of the Earth (Russia) and Institute of Geophysics (Ukraine) over several decades and now consists of many thousands of records of data in our archives. The MPDB was, and continues to be in big demand especially since recent launching in near Earth orbit of the mini-constellation of three satellites - Oersted (in 1999), Champ (in 2000), and SAC-C (in 2000) which will provide lithospheric magnetic maps with better spatial and amplitude resolution (about 1 nT). The MPDB is focused on lower crustal and upper mantle rocks and will include data on mantle xenoliths, serpentinized ultramafic rocks, granulites, iron quartzites and rocks from Archean-Proterozoic metamorphic sequences from all around the world. A substantial amount of data is coming from the area of unique Kursk Magnetic Anomaly and Kola Deep Borehole (which recovered 12 km of continental crust). A prototype MPDB can be found on the Geodynamics Branch web server of Goddard Space Flight Center at http://core2.gsfc.nasa.gov/terr_mag/magnpetr.html. The MPDB employs a searchable relational design and consists of 7 interrelated tables. The schema of database is shown at http://core2.gsfc.nasa.gov/terr_mag/doc.html. MySQL database server was utilized to implement MPDB. The SQL (Structured Query Language) is used to query the database. To present the results of queries on WEB and for WEB programming we utilized PHP scripting language and CGI scripts. The prototype MPDB is designed to search database by major satellite magnetic

78 FR 49507 - Genesis Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-14

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-2112-000] Genesis Solar, LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Genesis Solar...

Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of the Martian Meteorites

NASA Technical Reports Server (NTRS)

2002-01-01

This volume contains abstracts that have been accepted for presentation at the conference on Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of Martian Meteorites, September 11-12, 2002, in Houston, Texas. Administration and publications support for this meeting were provided by the staff of the Publications and Program Services Department at the Lunar and Planetary Institute.

EuroGEOSS/GENESIS ``e-Habitat'' AIP-3 Use Scenario

NASA Astrophysics Data System (ADS)

Mazzetti, P.; Dubois, G.; Santoro, M.; Peedell, S.; de Longueville, B.; Nativi, S.; Craglia, M.

2010-12-01

Natural ecosystems are in rapid decline. Major habitats are disappearing at a speed never observed before. The current rate of species extinction is several orders of magnitude higher than the background rate from the fossil record. Protected Areas (PAs) and Protected Area Systems are designed to conserve natural and cultural resources, to maintain biodiversity (ecosystems, species, genes) and ecosystem services. The scientific challenge of understanding how environmental and climatological factors impact on ecosystems and habitats requires the use of information from different scientific domains. Thus, multidisciplinary interoperability is a crucial requirement for a framework aiming to support scientists. The Group on Earth Observations (or GEO) is coordinating international efforts to build a Global Earth Observation System of Systems (GEOSS). This emerging public infrastructure is interconnecting a diverse and growing array of instruments and systems for monitoring and forecasting changes in the global environment. This “system of systems” supports multidisciplinary and cross-disciplinary scientific researches. The presented GEOSS-based interoperability framework facilitates the discovery and exploitation of datasets and models from heterogeneous scientific domains and Information Technology services (data sources). The GEO Architecture and Data Committee (ADC) launched the Architecture Implementation Pilot (AIP) Initiative to develop and deploy new processes and infrastructure components for the GEOSS Common Infrastructure (GCI) and the broader GEOSS architecture. The current AIP Phase 3 (AIP-3) aims to increase GEOSS capacity to support several strategic Societal Benefit Areas (SBAs) including: Disaster Management, Health/Air Quality, Biodiversity, Energy, Health/Disease and Water. As to Biodiversity, the EC-funded EuroGEOSS (http://www.eurogeoss.eu) and GENESIS (http://www.genesis-fp7.eu) projects have developed a use scenario called �

Improving Our Understanding of Tropical Cyclone Genesis

DTIC Science & Technology

2009-09-30

increasingly convergent. Figure 3: Model-derived outgoing long-wave radiation (W m−2) image of Typhoon Ketsana 2003 (left) and Typhoon Mawar 2005 (right...the Typhoon Ketsana simulation (left) and Typhoon Mawar simulation (right). Asterisks denote the time of pre-genesis convective bursts in each...5 s−1) for the Typhoon Ketsana simulation (left) and Typhoon Mawar simulation (right). IMPACT/APPLICATIONS A combined observational and numerical

33 CFR 147.825 - Chevron Genesis Spar safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Description. The Chevron Genesis Spar, Green Canyon 205A (GC205A), is located at position 27°46′46.365″ N, 90... is a safety zone. (b) Regulation. No vessel may enter or remain in this safety zone except the...

Petrology and Composition of HED Polymict Breccias

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.; Herrin, J. S.; Mertzman, S. A.; Mertzman, K. R.

2010-01-01

The howardite, eucrite and diogenite (HED) clan of meteorites forms the largest suite of achondrites with over 900 named members. The HEDs are igneous rocks and breccias of igneous rocks from a differentiated asteroid [1]. The consensus view is that these rocks hail from the asteroid 4 Vesta, which will be the first target of NASA's Dawn mission. When Dawn arrives at Vesta, she will begin remote imagery and spectroscopy of the surface. The surface she will observe will be dominated by rocks and soils mixed through impact gardening. To help with the interpretation of the remotely sensed data, we have begun a project on the petrologic and compositional study of a suite of HED polymict breccias. Here we report on the preliminary findings of this project.

Modulation of Subseasonal Tropical Cyclone Genesis In The Western North Pacific By Wave Activities

NASA Astrophysics Data System (ADS)

Gao, Jianyun; Cheung, Kevin K. W.

2017-04-01

Tropical cyclone (TC) activity is well known to possess variability on multiple timescales, ranging from inter-decadal to intraseasonal. In this study, the subseasonal variability of TC genesis in the western North Pacific (WNP) is examined during summer (May-October) for the period of 1979-2015. In particular, clustering of TC activity within subseasonal timescale is the focus. First, three phases (active, normal and inactive phases) of TC clustering are defined based on the statistics of genesis frequency. Then the modes of subseasonal modulation of these three phases by intraseasonal (30-60-day) oscillation (ISO), biweekly (10-20-day) oscillation (BWO), and the convectively coupled equatorial waves (CCEW), including Rossby, Kelvin, and mixed Rossby-gravity and tropical depression-type waves are considered. It is found that the embedding large-scale circulation is significantly different between the inactive phase and the other phases. Further, the intensities and propagation phases of the ISO, BWO and CCEW play different roles to modulate TC genesis frequency during the active and normal phase. Considering the lag correlation of these subseasonal modulation modes and TC genesis, it is possible to construct a statistical model for the purpose of extended-range forecasting of subseasonal variability of TC occurrence over the WNP.

Cleaning Genesis Mission Payload for Flight with Ultra-Pure Water and Assembly in ISO Class 4 Environment

NASA Technical Reports Server (NTRS)

Allton, Judith H.

2012-01-01

Genesis mission to capture and return to Earth solar wind samples had very stringent contamination control requirements in order to distinguish the solar atoms from terrestrial ones. Genesis mission goals were to measure solar composition for most of the periodic table, so great care was taken to avoid particulate contamination. Since the number 1 and 2 science goals were to determine the oxygen and nitrogen isotopic composition, organic contamination was minimized by tightly controlling offgassing. The total amount of solar material captured in two years is about 400 micrograms spread across one sq m. The contamination limit requirement for each of C, N, and O was <1015 atoms/sq cm. For carbon, this is equivalent to 10 ng/cm2. Extreme vigilance was used in pre-paring Genesis collectors and cleaning hardware for flight. Surface contamination on polished silicon wafers, measured in Genesis laboratory is approximately 10 ng/sq cm.

Molecular Contamination on Anodized Aluminum Components of the Genesis Science Canister

NASA Technical Reports Server (NTRS)

Burnett, D. S.; McNamara, K. M.; Jurewicz, A.; Woolum, D.

2005-01-01

Inspection of the interior of the Genesis science canister after recovery in Utah, and subsequently at JSC, revealed a darkening on the aluminum canister shield and other canister components. There has been no such observation of film contamination on the collector surfaces, and preliminary spectroscopic ellipsometry measurements support the theory that the films observed on the anodized aluminum components do not appear on the collectors to any significant extent. The Genesis Science Team has made an effort to characterize the thickness and composition of the brown stain and to determine if it is associated with molecular outgassing.Detailed examination of the surfaces within the Genesis science canister reveals that the brown contamination is observed to varying degrees, but only on surfaces exposed in space to the Sun and solar wind hydrogen. In addition, the materials affected are primarily composed of anodized aluminum. A sharp line separating the sun and shaded portion of the thermal closeout panel is shown. This piece was removed from a location near the gold foil collector within the canister. Future plans include a reassembly of the canister components to look for large-scale patterns of contamination within the canister to aid in revealing the root cause.

75 FR 52966 - Notice of Availability of the Final Environmental Impact Statement for the Genesis Solar, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... Genesis Solar Energy Project and Proposed California Desert Conservation Area Plan Amendment AGENCY... Solar LLC's Genesis Solar Energy Project (GSEP) and by this notice is announcing its availability. DATES... amendment the CDCA Plan to make the area suitable for solar energy development; a reduced acreage...

Strontium Isotopes of Gaskiers Cap Carbonate, Avalon, Newfoundland: Sequential Digestion Aids Interpretation of Petrologic Complexity

NASA Astrophysics Data System (ADS)

Tang, T.; Raub, T. D.; Wang, Z.

2013-12-01

Strontium isotope chemostratigraphy in limestones appear to track a near monotonic rising trend from the tail of the breakup of the supercontinent Rodinia at ~750 Ma into the latest Ediacaran Period at ~ 550 Ma (Halverson et al., 2007). This offers a potentially powerful tool to date carbonates occurring within this time period of stepwise environmental oxidation. Furthermore, aspects of the Snowball Earth hypothesis predict that some magnitude of 87Sr/86Sr excursions of seawater is expected at multiple intervals during this time, because balancing influences from prolonged synglacial hydrothermal input in entombed oceans, deglacial freshwater plumes of varying temperature and salinity, and enhanced postglacial silicate weathering from the continents can leave multiple isotopic trends plausible during these critical intervals. The positions of these deglaciations appear to correlate specifically to marine oxidation events, with cause/effect relations still under investigation. To capitalize on all of these interpretive possibilities, it is crucial to establish a high-precision and high-resolution strontium chemostratigraphic record over both short and long timescales. However, difficulties in establishing such a record based on carbonates are associated with 1) diagenetic influence over extensive geological time; and 2) petrologic complexities of the studied samples. Using a sequential digestion technique, Liu et al. (2013) demonstrated that these hurdles can be overcome, and that primary 87Sr/86Sr ratios of contemporaneous seawater can be obtained from Marinoan cap dolostones (~635 Ma), which have considerably less Sr than limestones, and whose Sr isotope compositions are commonly ignored in the strontium chemostratigraphic record. This leads to several viable, specific interpretations about the origin of Marinoan cap carbonate: either 1) very fast deposition; 2) slow deposition in a long-Sr-residence-time ocean; 3) mid-cap deposition in a freshwater "Glacial Lake

Metamorphic sole genesis at the base of ophiolite nappes: Insights from numerical models

NASA Astrophysics Data System (ADS)

Yamato, Philippe; Agard, Philippe; Duretz, Thibault

2015-04-01

Obduction emplaces oceanic lithosphere on top of continental lithosphere. Although a number of studies have focused on this enigmatic process, the initial stages of obduction remain poorly understood. Field, petrological, and geochronological data reveal that during the first stages of the obduction (i.e., during the first 1-2 Myrs) a HT-LP metamorphic sole (~700-800 ° C and ~1 GPa) is systematically welded at the base of ophiolite nappes. However, the reason why such welding of the ophiolite soles occurs at these particular P-T conditions, and only at the onset of obduction, is still an open issue. The aim of this study is to explore the conditions required to explain the genesis of metamorphic soles. For this, we employ two-dimensional numerical modelling, constrained by the wealth of available data from the Oman ophiolite. We first present a thermo-kinematic model in which the velocity field is prescribed in order to simulate obduction initiation. The heat advection-diffusion equation is solved at each time step. The model is intentionally kept simple in order to control each parameter (e.g., convergence rate, dip angle, thermal age) and to test its influence on the resulting P-T conditions obtained through time along the obduction interface. Results show that the key factor allowing the formation of metamorphic soles is the age of the oceanic lithosphere involved. Moreover, we speculate that the reason why metamorphic soles are always welded at the same P-T conditions is due to the fact that, at these particular conditions, strength jumps occur within the oceanic lithosphere. These jumps lead to changes in strain localisation and allow the spalling of oceanic crust and its juxtaposition to the ophiolite nappe. This hypothesis is further tested using thermo-mechanical models in which the obduction initiates dynamically (only initial and boundary conditions are prescribed). The interplay between the temperature evolution and the mechanical behaviour is then

Petrologic implications of plate tectonics.

PubMed

Yoder, H S

1971-07-30

Petrologists can make significant contributions to the plate tectonic concept. Fixing the stability fields of the principal rock types involved will provide the limits of pressure and temperature of the various environments. Experimental determination of the partition coefficients of the trace elements will be helpful. Studies of the partial melting behavior of possible parental materials in the absence and presence of water, especially the undersaturated region, will contribute to the understanding of magma production. Experimental observations on the rheological properties of the peridotites below and just above the solidus will lead to a better evaluation of the convective mechanism. Measurement of the fundamental properties of rocks, such as the density of solids and liquids at high pressures and temperatures, would contribute to understanding the concepts of diapiric rise, magma segregation, and the low-velocity zone. Broader rock sampling of the oceanic areas of all environments will do much to define the petrologic provinces. The field petrologist specializing in the Paleozoic regions and Precambrian shields can contribute by examining those regions for old plate boundaries and devising new criteria for their recognition.

Blending Curriculum with Research in an Undergraduate Petrology Course: A Recipe for Success?

NASA Astrophysics Data System (ADS)

Gonzales, D. A.; Semken, S. C.

2009-12-01

In this presentation we discuss the design, key curricular elements, and strengths and weaknesses of an undergraduate course in the Department of Geosciences at Fort Lewis College that was recast to focus on petrologic studies in the Southern Rocky Mountains and Colorado Plateau. Redesign of the course retained an additional petrology option in the curriculum and offered undergraduates a richer opportunity to learn and practice science-research skills. This course emphasizes direct engagement and student responsibility for learning: traits valuable in transforming undergraduates into experienced and competent professionals. Previous offerings of this course have been field based, each having a unique context for research. The primary pedagogical strategy was to blend field studies with inquiry to promote authentic, student-driven research. Students applied and tested their prior knowledge, and used observational and interpretative skills, to investigate major regional rock bodies and geologic histories, as opposed to completing a set of activities with predefined outcomes. In 2010, students will work on an NSF-funded project to test hypotheses on the origin and evolution of mafic magmas of the Navajo volcanic field. This research will most involve petrographic and microanalytical techniques on rock specimens with a subordinate amount of field work. Formative and summative assessment data for previous offerings of this course reveal that these classes have an impact on the academic interests and future successes of students. Assessment data collected from students, and other faculty that interacted with them, indicate that students in this research-oriented petrology course have gained a greater understanding of the elements and complications of research. They have also developed geologic skills and a passion for geologic research that have influenced subsequent academic (and later career) paths of the students.

Dynamic Stability Testing of the Genesis Sample Return Capsule

NASA Technical Reports Server (NTRS)

Cheatwood, F. McNeil; Winchenbach, Gerald L.; Hathaway, Wayne; Chapman, Gary

2000-01-01

This paper documents a series of free flight tests of a scale model of the Genesis Sample Return Capsule. These tests were conducted in the Aeroballistic Research Facility (ARF), located at Eglin AFB, FL, during April 1999 and were sponsored by NASA Langley Research Center. Because these blunt atmospheric entry shapes tend to experience small angle of attack dynamic instabilities (frequently leading to limit cycle motions), the primary purpose of the present tests was to determine the dynamic stability characteristics of the Genesis configuration. The tests were conducted over a Mach number range of 1.0 to 4.5. The results for this configuration indicate that the models were dynamically unstable at low angles of attack for all Mach numbers tested. At Mach numbers below 2.5, the models were also unstable at the higher angles of attack (above 15 deg), and motion amplitudes of up to 40 deg were experienced. Above Mach 2.5, the models were dynamically stable at the higher angles of attack.

Phase petrology reveals shallow magma storage prior to large explosive silicic eruptions at Hekla volcano, Iceland

NASA Astrophysics Data System (ADS)

Weber, Gregor; Castro, Jonathan M.

2017-05-01

Understanding the conditions that culminate in explosive eruptions of silicic magma is of great importance for volcanic hazard assessment and crisis mitigation. However, geological records of active volcanoes typically show a wide range of eruptive behavior and magnitude, which can vary dramatically for individual eruptive centers. In order to evaluate possible future scenarios of eruption precursors, magmatic system variables for different eruption types need to be constrained. Here we use petrological experiments and microanalysis of crystals to clarify the P-T-x state under which rhyodacitic melts accumulated prior to the H3 eruption; the largest Holocene Plinian eruption of Hekla volcano in Iceland. Cobalt-buffered, H2O-saturated phase equilibrium experiments reproduce the natural H3 pumice phenocryst assemblage (pl > fa + cpx > ilm + mt > ap + zrc) and glass chemistry, at 850 ± 15°C and PH2O of 130 to 175 MPa, implying shallow crustal magma storage between 5 and 6.6 km. The systematics of FeO and anorthite (CaAl2Si2O8) content in plagioclase reveal that thermal gradients were more important than compositional mixing or mingling within this magma reservoir. As these petrological findings indicate magma storage much shallower than is currently thought of Hekla's mafic system, we use the constrained storage depth in combination with deformation modeling to forecast permissible surface uplift patterns that could stem from pre-eruptive magma intrusion. Using forward modeling of surface deformation above various magma storage architectures, we show that vertical surface displacements caused by silicic magma accumulation at ∼6 km depth would be narrower than those observed in recent mafic events, which are fed from a lower crustal storage zone. Our results show how petrological reconstruction of magmatic system variables can help link signs of pre-eruptive geophysical unrest to magmatic processes occurring in reservoirs at shallow depths. This will enhance our

Mineralogy and Petrology of COMET WILD2 Nucleus Samples

NASA Technical Reports Server (NTRS)

Zolensky, Michael; Bland, Phil; Bradley, John; Brearley, Adrian; Brennan, Sean; Bridges, John; Brownlee, Donald; Butterworth, Anna; Dai, Zurong; Ebel, Denton

2006-01-01

The sample return capsule of the Stardust spacecraft will be recovered in northern Utah on January 15, 2006, and under nominal conditions it will be delivered to the new Stardust Curation Laboratory at the Johnson Space Center two days later. Within the first week we plan to begin the harvesting of aerogel cells, and the comet nucleus samples they contain for detailed analysis. By the time of the LPSC meeting we will have been analyzing selected removed grains for more than one month. This presentation will present the first results from the mineralogical and petrological analyses that will have been performed.

Genesis Science Team Report on Mission Status

NASA Astrophysics Data System (ADS)

Burnett, D. S.

2005-12-01

The Genesis Discovery Mission exposed pure materials to the solar wind at the L1 Lagrangian point for 27 months between December 2001 and April 2004. These were returned for analysis in terrestrial laboratories in Sept 2004. The general science objectives for Genesis are: (1) measure solar isotopic abundance ratios to the precision required for planetary science problems, (2) improve the accuracy of photospheric elemental abundances by a least a factor of three, (3) provide independent analyses of the 3 major solar wind regimes and (4) provide a reservoir of solar matter for subsequent studies. Based on these general objectives, we are working towards a list of 18 specific prioritized measurement objectives, the first 5 of which are isotopic measurements. The two highest priority objectives are the isotopic compositions of O and N; to obtain a higher signal to background ratio for these elements, a concentrator (focusing ion telescope) was built at LANL to provide a factor of 20 fluence enhancement for elements lighter than P on a 30 mm radius target. The concentrator performed well in flight. A variety of other collector materials, tailored to specific analytical approaches, were mounted in 5 arrays of 55 hexagons, 4 cm point to point. Three of the arrays were used to provide the independent regime (coronal hole, low speed interstream, and coronal mass ejection) samples. The solar wind regime was measured by LANL Solar Wind Monitors on the Genesis spacecraft and the appropriate array exposed while the inappropriate array remained shielded. Array switchouts were carried out flawlessly during flight. Sample analyses have been slowed considerably by a parachute deployment failure which caused a crash of the sample return capsule upon reentry and by the presence of an in-flight contamination film, affectionately referred to as the brown stain. The crash has led to major loss of collector materials, along with significant pitting and scratching of the surviving

Geochemistry, petrology, and palynology of the Pond Creek coal bed, northern Pike and southern Martin counties, Kentucky

USGS Publications Warehouse

Hower, J.C.; Ruppert, L.F.; Eble, C.F.; Clark, W.L.

2005-01-01

The geochemistry, petrology, and palynology of the Duckmantian-age Pond Creek coal bed were investigated in northern Pike and southern Martin counties, eastern Kentucky. The coal bed exhibits significant vertical variation in the investigated geochemical parameters, with many diagenetic overprints of the original geochemistry. Included in the range of geochemical signatures are the presence of elements, particularly TiO2 and Zr, suggesting the detrital influences at the time of deposition of a low-vitrinite durain; a high CaO zone with elevated B/Be, both suggesting marine influence, in a lithotype in the middle of the coal bed; and the postdepositional emplacement of pyrite in the uppermost lithotype. Individual lithotypes, each representing distinct depositional environments, all complicated to some degree by diagentic overprints, comprise the complex history of the coal bed. ?? 2004 Elsevier B.V. All rights reserved.

Tropical Cyclone Genesis Efficiency: Mid-Level Versus Bottom Vortex

DTIC Science & Technology

2011-12-16

storm strength). Figure 4b shows the time evolutions of the corresponding maximum surface wind speed from the four experiments. Based on the definition...Pacific during summer. Mon. Wea. Rev., 124, 2245–2266. Chen, S. S. and W. M. Frank, 1993: A numerical study of the genesis of extratropical convective

"MERAPIDATA": New Petrologic and Geochemical Database of the Merapi Volcano, Central Java, Indonesia

NASA Astrophysics Data System (ADS)

Borisova, A. Y.; Martel, C.; Pratomo, I.; Toutain, J.; Sumarti, S.; Surono, S.

2011-12-01

Petrologic and geochemical databases of erupted products are critical for monitoring and predicting the evolution of active volcanoes. To monitor the activity of one of the most dangerous volcanoes in the world, Merapi Volcano in Indonesia, in the framework of the new instrumental site VELI (Volcans Explosifs - Laboratoires Indonésiens labelled by INSU in 2009 in France), we generated "MERAPIDATA", a complete database of available petrologic and geochemical data published in the literature on pyroclastic flows, tephra, lavas and xenoliths coupled with the exact ages of historical flows [1] or estimated ages based on 14C geochronology [2]. "MERAPIDATA" permits to access complete petrologic, geochemical, and geochronological information (e.g., major, trace element and Sr-Nd-Pb-O isotopic composition of the bulk volcanic rocks, xenoliths, minerals and glasses; textural information; type of eruption; classification) of a given volcanic product or series. In addition to ~300 published volcanic products, new data on 2 pyroclastic flows, 1 tephra and 4 ash samples collected on northern and western slopes of the volcano in October and November 2010 during subplinian type eruption have been added to "MERAPIDATA". The 2010 ash sample chemistry allows classifying them as high-K basaltic andesite. The ash samples demonstrate major and trace element compositions typical for the high-K series. For the first time, we obtained complete data on the Merapi ash samples which characterized by low L.O.I. ≤ 0.58 wt%, CO2total ≤ 0.05 wt%, H2Ototal = 0.3 - 0.5 wt%, Stotal ≤ 0.13 wt% and moderate Cl (550 - 1120 ppm) contents. The ash-leachates produced by leaching experiments demonstrate constant F/Cl ratios (0.05 ± 0.01) and Ca-Na-K enrichment (Ca/Na= 3 - 7, Na/K = 1 - 5). Sr-Nd-Pb-O isotopic analyses on the 2010 Merapi products are in progress. New petrologic (e.g., melt and fluid inclusion data, T - P - fO2 - aH2O - aCO2) and geochemical (e.g., volatile, major, trace element and

GENESI-DR Portal: a scientific gateway to distributed repositories

NASA Astrophysics Data System (ADS)

Goncalves, Pedro; Brito, Fabrice; D'Andria, Fabio; Cossu, Roberto; Fusco, Luigi

2010-05-01

GENESI-DR (Ground European Network for Earth Science Interoperations - Digital Repositories) is a European Commission (EC)-funded project, kicked-off early 2008 lead by ESA; partners include Space Agencies (DLR, ASI, CNES), both space and no-space data providers such as ENEA (I), Infoterra (UK), K-SAT (N), NILU (N), JRC (EU) and industry as Elsag Datamat (I), CS (F) and TERRADUE (I). GENESI-DR intends to meet the challenge of facilitating "time to science" from different Earth Science disciplines in discovery, access and use (combining, integrating, processing, …) of historical and recent Earth-related data from space, airborne and in-situ sensors, which are archived in large distributed repositories. "Discovering" which data are available on a "geospatial web" is one of the main challenges ES scientists have to face today. Some well- known data sets are referred to in many places, available from many sources. For core information with a common purpose many copies are distributed, e.g., VMap0, Landsat, and SRTM. Other data sets in low or local demand may only be found in a few places and niche communities. Relevant services, results of analysis, applications and tools are accessible in a very scattered and uncoordinated way, often through individual initiatives from Earth Observation mission operators, scientific institutes dealing with ground measurements, service companies or data catalogues. In the discourse of Spatial Data Infrastructures, there are "catalogue services" - directories containing information on where spatial data and services can be found. For metadata "records" describing spatial data and services, there are "registries". The Geospatial industry coins specifications for search interfaces, where it might do better to reach out to other information retrieval and Internet communities. These considerations are the basis for the GENESI-DR scientific portal, which adopts a simple model allowing the geo-spatial classification and discovery of

Petrology of Two Itokawa Particles: Comparison with Equilibrated LL Chondrites

NASA Technical Reports Server (NTRS)

Komatsu, M.; Mikouchi, T.; Arai, T.; Fagan, T. J.; Zolensky, M.; Hagiya, K.; Ohsumi, K.; Karouji, Y.

2015-01-01

A strong link between Itokawa particles and LL chondrites was confirmed by preliminary examinations of Hayabusa particles [e.g., 1, 2]. Both poorly equilibrated and highly equilibrated particles have been found among the grains returned from Itokawa [1], and it is suggested that they correspond to LL4 and LL5-6, respectively. Here we report the petrography of two Itokawa particles and TEM study of one, and compare them to Antarctic LL chondrites with variable petrologic types (LL4-LL7) in order to understand the metamorphic history of asteroid Itokawa.

Astronaut David Scott - Sample - "Genesis Rock" - MSC

NASA Image and Video Library

1971-08-12

S71-43477 (12 Aug. 1971) --- Astronaut David R. Scott, right, commander of the Apollo 15 mission, gets a close look at the sample referred to as "Genesis rock" in the Non-Sterile Nitrogen Processing Line (NNPL) in the Lunar Receiving Laboratory (LRL) at the Manned Spacecraft Center (MSC). Scientist-astronaut Joseph P. Allen IV, left, an Apollo 15 spacecraft communicator, looks on with interest. The white-colored rock has been given the permanent identification of 15415.

ENSO Effect on East Asian Tropical Cyclone Landfall via Changes in Tracks and Genesis in a Statistical Model

NASA Technical Reports Server (NTRS)

Yonekura, Emmi; Hall, Timothy M.

2014-01-01

Improvements on a statistical tropical cyclone (TC) track model in the western North Pacific Ocean are described. The goal of the model is to study the effect of El Nino-Southern Oscillation (ENSO) on East Asian TC landfall. The model is based on the International Best-Track Archive for Climate Stewardship (IBTrACS) database of TC observations for 1945-2007 and employs local regression of TC formation rates and track increments on the Nino-3.4 index and seasonally varying climate parameters. The main improvements are the inclusion of ENSO dependence in the track propagation and accounting for seasonality in both genesis and tracks. A comparison of simulations of the 1945-2007 period with observations concludes that the model updates improve the skill of this model in simulating TCs. Changes in TC genesis and tracks are analyzed separately and cumulatively in simulations of stationary extreme ENSO states. ENSO effects on regional (100-km scale) landfall are attributed to changes in genesis and tracks. The effect of ENSO on genesis is predominantly a shift in genesis location from the southeast in El Nino years to the northwest in La Nina years, resulting in higher landfall rates for the East Asian coast during La Nina. The effect of ENSO on track propagation varies seasonally and spatially. In the peak activity season (July-October), there are significant changes in mean tracks with ENSO. Landfall-rate changes from genesis- and track-ENSO effects in the Philippines cancel out, while coastal segments of Vietnam, China, the Korean Peninsula, and Japan show enhanced La Nina-year increases.

Quaternary Basanitic Rocks within the Eastern Anatolian Volcanism (Turkey): Petrological and Geochemical Constrains

NASA Astrophysics Data System (ADS)

Özdemir, Yavuz; Mercan, Çaǧrı; Oyan, Vural; Atakul-Özdemir, Ayşe

2017-04-01

The Eastern Anatolian Cenozoic continental intraplate volcanism was initiated in Middle Miocene as a result of the convergence between the Arabian and Anatolian plates. The origin of Eastern Anatolian volcanism has been the focus of many petrological studies that have aimed to resolve the relative contributions of asthenospheric mantle and/or lithospheric mantle with/without subduction component in the genesis of magmas that compositionally have many affinities to ocean island basalts (OIB) and volcanic arcs. Volcanism in the region characterized by mainly stratovolcanoes, basaltic lava plateaus and are dominantly spread at the northern parts of Bitlis Pötürge Massif (BPM). Our study focuses on a small scale Quaternary basaltic system that firstly observed within the BPM. The volcanic rocks of our study located 50 km to the south of Lake Van and are basanitic in composition. They exposed along K-G striking tensional fissures and crosscut the Upper unit of the Bitlis Massif. Initial products of the volcanism are scoria fall deposits. Thick basanitic lava flows overly the pyroclastics and formed columnar structures. The basanites are generally fine-grained with phenocrysts of olivine+clinopyroxene. The groundmass is typically of clinopyroxene, olivine and Ti magnetite and Cr spinel with interstitial nepheline. The olivine phenocrysts are typically euhedral to subhedral with Forsterite contents of Fo73-83. Clinopyroxenes are highly calcic and show modest variations in Wo47-52-En34-42-Fs10-15 and are weakly zoned with mg# 89-87 at cores to 86-84 at rims. Nephelines occur as minor minerals within the networks of other groundmass minerals. Ti rich and Fe-Cr spinels occur as inclusions in olivine and clinopyroxenes as well as within the groundmass. LILE and LREE enrichments over HFSE and HREE suggest similarities with magmas generated from enriched mantle sources. EC-AFC modeling of trace element and isotope compositions indicates that assimilation of crustal

Decontaminating Solar Wind Samples with the Genesis Ultra-Pure Water Megasonic Wafer Spin Cleaner

NASA Technical Reports Server (NTRS)

Calaway, Michael J.; Rodriquez, M. C.; Allton, J. H.; Stansbery, E. K.

2009-01-01

The Genesis sample return capsule, though broken during the landing impact, contained most of the shattered ultra-pure solar wind collectors comprised of silicon and other semiconductor wafers materials. Post-flight analysis revealed that all wafer fragments were littered with surface particle contamination from spacecraft debris as well as soil from the impact site. This particulate contamination interferes with some analyses of solar wind. In early 2005, the Genesis science team decided to investigate methods for removing the surface particle contamination prior to solar wind analysis.

Iron disulfide minerals and the genesis of roll-type uranium deposits.

USGS Publications Warehouse

Reynolds, R.L.; Goldhaber, M.B.

1983-01-01

Studies of the distribution of and textural relationships among pyrite and marcasite in host rocks for a number of roll-type sedimentary U deposits have enabled identification of several generations of FeS2 minerals. A critical factor influencing mineral formation is the complex relationship of pH and the S species that are precursors of FeS2 minerals. The presence or absence of intrinsic organic matter for bacterial sulphate reduction also plays a key role. In deposits lacking such organic matter, the pre-ore is often euhedral pyrite and the ore-stage is marcasite. In contrast, in deposits containing organic matter the pre-ore is pyrite occurring as framboids or as replacements of plant material, and the ore-stage is also pyrite. These contrasting FeS2 assemblages and their respective modes of origin are consistent with previously proposed biogenic and nonbiogenic theories of the genesis of roll-type U deposits. -J.E.S.

Rethinking how Undergraduate ``Hard Rock'' Petrology is Taught

NASA Astrophysics Data System (ADS)

Reid, M. R.

2010-12-01

A course in "hard rock" petrology forms a core component of undergraduate training in the geosciences. In most cases, the subjects of igneous and metamorphic petrology are combined in a single course and the course is traditionally structured so that the two subjects are covered in series. This approach enables students to focus on each subject separately, with knowledge of igneous rocks helping students to understand metamorphic rock protoliths. Student assessment shows, however, that this approach tends to compartmentalize learning and the two main subjects might just as well be taught in separate courses. In practical applications such as fieldwork, students must be able to access their understanding of igneous and metamorphic rocks virtually simultaneously. To better integrate student learning, I developed a spiral learning approach to teaching petrology (e.g., Bruner, 1990; Dyar et al., 2004) so that commonalities could be revisited several times over the course of a semester and, in so doing, students' grasp of the fundamental insights provided by igneous and metamorphic rocks could be scaffolded into greater understanding. The course initially focuses on the dynamics of the environments in which igneous and metamorphic rocks form: heat flow, fluid flow, and plate tectonics. Several subsequent weeks explore topics relevant to identifying and understanding igneous and metamorphic rocks in the field: crystal nucleation and growth, the roles of pressure and heat, and field classification. Laboratory exercises parallel this structure, also emphasizing observations that are valuable in the field: the relationship between minerals and rocks, textural observations, and general rock classification. The final portion of the course explores “hard rocks” in more detail with a greater emphasis on the interplay between chemistry and mineralogy. A variety of learner-centered activities in the course help students bridge the gap between novice and expert and include

Petrology of basalts from Loihi Seamount, Hawaii

NASA Astrophysics Data System (ADS)

Hawkins, James; Melchior, John

1983-12-01

Loihi Seamount is the southeasternmost active volcano of the Emperor-Hawaii linear volcanic chain. It comprises a spectrum of basalt compositional varieties including basanite, alkali basalt, transitional basalt and tholeiite. Samples from four dredge collections made on Scripps Institution of Oceanography Benthic Expedition in October 1982 are tholeiite. The samples include highly vesicular, olivine-rich basalt and dense glass-rich pillow fragments containing olivine and augite phenocrysts. Both quartz-normative and olivine-normative tholeiites are present. Minor and trace element data indicate relatively high abundances of low partition coefficient elements (e.g., Ti, K, P. Rb, Ba, Zr) and suggest that the samples were derived by relatively small to moderate extent of partial melting, of an undepleted mantle source. Olivine composition, MgO, Cr and Ni abundances, and Mg/(Mg+Fe), are typical of moderately fractionated to relatively unfractionated "primary" magmas. The variations in chemistry between samples cannot be adequately explained by low-pressure fractional crystallization but can be satisfied by minor variations in extent of melting if a homogeneous source is postulated. Alternatively, a heterogeneous source with variable abundances of certain trace elements, or mixing of liquids, may have been involved. Data for 3He/ 4He, presented in a separate paper, implies a mantle plume origin for the helium composition of the Loihi samples. There is little variation in the helium isotope ratio for samples having different compositions and textures. The helium data are not distinctive enough to unequivocally separate the magma sources for the tholeiitic rocks from the other rock types such as Loihi alkalic basalts and the whole source region for Loihi may have a nearly uniform helium compositions even though other element abundances may be variable. Complex petrologic processes including variable melting, fractional crystallization and magma mixing may have blurred

The genesis of collective health in Brazil.

PubMed

Vieira-da-Silva, Ligia Maria; Pinell, Patrice

2014-03-01

During the 1970s in Brazil a social space directed towards health problems on the population level, called collective health, was created and institutionalised. To what extent did this Brazilian invention correspond to a specific socio-historical practice? The works published on this topic have considered social medicine as a homogeneous phenomenon without empirically studying the specificities of national experiences. To bridge this gap, a historical study on the genesis of collective health in Brazil was carried out based on Bourdieu's field theory. The interaction between the paths of the founders and the conditions of historical possibilities were researched through documentary and bibliographical sources, as well as through in-depth interviews of the founders. This social space originated from a meeting of agents with different social backgrounds but who interconnected, creating a structure that was independent of each agent considered individually. One of the components of this establishment was the joining of theoretical production and the implementation of health reforms that resulted in the organisation of a universal health system. This study attempts to show how the international political situation and the contradictions of the national crisis created a universe of possibilities, allowing for the genesis of this sui generis space in Brazil. © 2013 The Authors. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

Petrology of lunar rocks and implication to lunar evolution

NASA Technical Reports Server (NTRS)

Ridley, W. I.

1976-01-01

Recent advances in lunar petrology, based on studies of lunar rock samples available through the Apollo program, are reviewed. Samples of bedrock from both maria and terra have been collected where micrometeorite impact penetrated the regolith and brought bedrock to the surface, but no in situ cores have been taken. Lunar petrogenesis and lunar thermal history supported by studies of the rock sample are discussed and a tentative evolutionary scenario is constructed. Mare basalts, terra assemblages of breccias, soils, rocks, and regolith are subjected to elemental analysis, mineralogical analysis, trace content analysis, with studies of texture, ages and isotopic composition. Probable sources of mare basalts are indicated.

Towards Calibrating the Vestan Regolith: Correlating the Petrology, Chemistry and Spectroscopy of Howardites

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Ammannito, E.; Hiroi, T.; De Angelis, S.; Di Iorio, T.; Pieters, C. M.; De Sanctis, C.

2013-01-01

The Dawn spacecraft carries a visible and infrared mapping spectrometer (VIR) [1] that has acquired spectra for the wavelength range 0.25-5.0 µm at various spatial resolutions covering much of the vestan surface [2]. Through comparison of VIR spectra with laboratory spectra of howardite, eucrite and diogenite meteorites, the distribution of more diogenite-rich and more eucrite-rich terranes on Vesta have been mapped [3], but these maps are qualitative in nature. The available laboratory spectra are not well-integrated with detailed sample petrology or composition limiting their utility for lithologic mapping. Importantly, howardites are now recognized to come in two subtypes, regolithic and fragmental [4]. The former are breccias assembled in part from true regolith, while the latter have had much less exposure to the space environment. We are attempting to develop a more quantitative basis for mapping the distribution of lithologic types on Vesta through acquiring laboratory spectra on splits of howardites that have been petrologically and chemically characterized [5]. Noble gas analyses have been done on some allowing identification of those howardites that have been exposed in the true regolith of Vesta [6].

From an active continental plate margin to continental collision: New constraints from the petrological, structural and geochronological record of the (ultra) high-P metamorphic Rhodope domain (N-Greece)

NASA Astrophysics Data System (ADS)

Mposkos, E.; Krohe, A.; Wawrzenitz, N.; Romer, R. L.

2012-04-01

The Rhodope domain occupies a key area along the suture between the European and the Apulian/Adriatic plate (Schmid et al., 2008), which collided in the early Tertiary (closure of the Vardar/Axios ocean, cf. Mposkos & Krohe, 2006). An integrated study of the geochronological, tectonic and petrological data of the Rhodope domain provides the unique opportunity resolving a 160 my lasting metamorphic evolution (Jurassic to Miocene) of an active plate margin to a high degree. The Greek Rhodope consists of several composite metamorphic complexes bounded by the Nestos thrust and several normal detachment systems. The PT- and structural records of the complexes constrain metamorphic, magmatic and tectonic processes, associated with subduction along a convergent plate margin including UHP metamorphism, MP to HP metamorphism associated with continental collision, and core complex formation linked to Aegean back arc extension. We focus on the Sidironero Complex that shows a polymetamorphic history. This is documented by SHRIMP and LA-ICP-MS U-Pb zircon ages of ca. 150 Ma from garnet-kyanite gneisses that are interpreted to record the HP/UHP metamorphism (Liati, 2005; Krenn et al., 2010). SHRIMP zircon ages of ca. 51 Ma from an amphibolitized eclogite is interpreted by Liati (2005) to record a second Eocene HP metamorphic event. We present new data from an integrated petrological, geochronological and tectonic study. Granulite facies and upper amphibolite facies metamorphic conditions are recorded by the mineral assemblage Grt-Ky-Bt-Pl-Kfs-Qtz-Rt and Grt-Ky-Bt-Ms-Pl-Qtz-Rt, respectively, in deformed migmatitic metapelites. Deformation occurred under granulite facies conditions. Monazites from the matrix, that formed during the granulite facies deformation, lack core/rim structures and are only locally patchy zoned. Monazite chemical compositions are related to varying reaction partners. Single grains and fractions of few grains yield ID-TIMS U-Pb ages that plot along the

[Sanation of biliary system using antiseptic decasan in complex treatment of cholangitis].

PubMed

Aripova, N U; Magzumov, I Kh

2014-02-01

Experience of treatment of 17 patients, suffering cholangitis of various genesis, using antiseptic Decasan, is presented. Clinical efficacy of the preparation in complex treatment of cholangitis, confirmed by results of the bile bacteriological investigation, was noted.

Pristine Igneous Rocks and the Genesis of Early Planetary Crusts

NASA Technical Reports Server (NTRS)

Warren, Paul H.; Lindstrom, David (Technical Monitor)

2002-01-01

Our studies are highly interdisciplinary, but are focused on the processes and products of early planetary and asteroidal differentiation, especially the genesis of the ancient lunar crust. The compositional diversity that we explore is the residue of process diversity, which has strong relevance for comparative planetology.

Analysis of Molecular Contamination on Genesis Collectors Through Spectroscopic Ellipsometry

NASA Technical Reports Server (NTRS)

McNamara, K. M.; Stansbery, Eileen K.

2005-01-01

Before the spacecraft returned to Earth in September, the Genesis mission had a preliminary assessment plan in place for the purpose of providing information on the condition and availability of collector materials to the science community as a basis for allocation requests. One important component of that plan was the evaluation of collector surfaces for molecular contamination. Sources of molecular contamination might be the on-orbit outgassing of spacecraft and science canister components, the condensation of thruster by-products during spacecraft maneuvers, or the condensation of volatile species associated with reentry. Although the non-nominal return of the Genesis spacecraft introduced particulate contamination to the collectors, such as dust and heatshield carbon-carbon, it is unlikely to have caused any molecular deposition. The contingency team's quick action in returning the damaged payload the UTTR cleanroom by 6 PM the evening of recovery help to ensure that exposure to weather conditions and the environment were kept to a minimum.

Hardgrove grindability index and petrology used as an enhanced predictor of coal feed rate

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

Hower, J.C.

1990-01-01

An improved predictor of coal pulverization behavior and coal feed rate is under development at the CAER based upon the interaction between Hardgrove Grindability Index (HGI) and coal petrology. With educated attention, this interaction may be a useful tool to enhance coal feed rates if cautiously extended to the mining environment where blends of coal lithotypes are produced.

Super-deep diamond genesis at Redox conditions of slab-mantle boundary

NASA Astrophysics Data System (ADS)

Gao, J.; Chen, B.; Wu, X.

2017-12-01

Diamond genesis is an intriguing issue for diamond resources and the deep carbon cycle of the Earth's interiors. Super-deep diamonds, representing only 6% of the global diamond population, often host inclusions with phase assemblages requiring a sublithospheric origin (>300 km). Being the windows for probing the deep Earth, super-deep diamonds with their distinctive micro-inclusions not only record a history of oceanic lithosphere subduction and upward transport at a depth of >250 km to even 1000 km, but indicate their genesis pertinent to mantle-carbonate melts in a Fe0-bufferred reduced condition. Our pilot experiments have evidenced the formation of diamonds from MgCO3-Fe0 system in a diamond anvil cell device at 25 GPa and 1800 K. Detailed experimental investigations of redox mechanism of MgCO3-Fe0 and CaCO3-Fe0 coupling have been conducted using multi-anvil apparatus. The conditions are set along the oceanic lithosphere subduction paths in the pressure-temperature range of 10-24 GPa and 1200-2000 K, covering the formation region of most super-deep diamonds. The clear reaction zones strongly support the redox reaction between carbonatitic slab and Fe0-bearing metals under mantle conditions. Our study has experimentally documented the possibility of super-deep diamond genesis at redox conditions of carbonateitic slab and Fe0-bearings. The kinetics of diamond formation as a function of pressure-temperature conditions are also discussed.

Nano-inclusions in diamond: Evidence of diamond genesis

NASA Astrophysics Data System (ADS)

Wirth, R.

2015-12-01

The use of Focused Ion Beam technology (FIB) for TEM sample preparation introduced approximately 15 years ago revolutionized the application of TEM in Geosciences. For the first time, FIB enabled cutting samples for TEM use from exactly the location we are interested in. Applied to diamond investigation, this technique revealed the presence of nanometre-sized inclusions in diamond that have been simply unknown before. Nanoinclusions in diamond from different location and origin such as diamonds from the Lower and Upper Mantle, metamorphic diamonds (Kazakhstan, Erzgebirge, Bohemia), diamonds from ophiolites (Tibet, Mongolia, Xinjiang, Ural Mountains), diamonds from igneous rocks (Hawaii, Kamchatka) and impact diamonds (Popigai Crater, Siberia) have been investigated during the last 15 years. The major conclusion of all these TEM studies is, that the nanoinclusions, their phases and phase composition together with the micro- and nanostructure evidence the origin of diamond and genesis of diamond. We can discriminate Five different mechanisms of diamond genesis in nature are observed: Diamond crystallized from a high-density fluid (Upper mantle and metamorphic diamond). Diamond crystallized from carbonatitic melt (Lower mantle diamond). Diamond precipitates from a metal alloy melt (Diamond from ophiolites). Diamond crystallized by gas phase condensation or chemical vapour condensation (CVD) (Lavas from Kamchatka, xenoliths in Hawaiian lavas). Direct transformation of graphite into diamond.

Eruptive stratigraphy of the Tatara-San Pedro complex, 36°S, sourthern volcanic zone, Chilean Andes: reconstruction method and implications for magma evolution at long-lived arc volcanic centers

USGS Publications Warehouse

Dungan, M.A.; Wulff, A.; Thompson, R.

2001-01-01

The Quaternary Tatara-San Pedro volcanic complex (36°S, Chilean Andes) comprises eight or more unconformity-bound volcanic sequences, representing variably preserved erosional remnants of volcanic centers generated during 930 ky of activity. The internal eruptive histories of several dominantly mafic to intermediate sequences have been reconstructed, on the basis of correlations of whole-rock major and trace element chemistry of flows between multiple sampled sections, but with critical contributions from photogrammetric, geochronologic, and paleomagnetic data. Many groups of flows representing discrete eruptive events define internal variation trends that reflect extrusion of heterogeneous or rapidly evolving magna batches from conduit-reservoir systems in which open-system processes typically played a large role. Long-term progressive evolution trends are extremely rare and the magma compositions of successive eruptive events rarely lie on precisely the same differentiation trend, even where they have evolved from similar parent magmas by similar processes. These observations are not consistent with magma differentiation in large long-lived reservoirs, but they may be accommodated by diverse interactions between newly arrived magma inputs and multiple resident pockets of evolved magma and / or crystal mush residing in conduit-dominated subvolcanic reservoirs. Without constraints provided by the reconstructed stratigraphic relations, the framework for petrologic modeling would be far different. A well-established eruptive stratigraphy may provide independent constraints on the petrologic processes involved in magma evolution-simply on the basis of the specific order in which diverse, broadly cogenetic magmas have been erupted. The Tatara-San Pedro complex includes lavas ranging from primitive basalt to high-SiO2 rhyolite, and although the dominant erupted magma type was basaltic andesite ( 52-55 wt % SiO2) each sequence is characterized by unique proportions of

Petrology and mineralogy of the Ningqiang carbonaceous chondrite

NASA Astrophysics Data System (ADS)

Wang, Y.; Hsu, W.

2009-07-01

We report detailed chemical, petrological, and mineralogical studies on the Ningqiang carbonaceous chondrite. Ningqiang is a unique ungrouped type 3 carbonaceous chondrite. Its bulk composition is similar to that of CV and CK chondrites, but refractory lithophile elements (1.01 × CI) are distinctly depleted relative to CV (1.29 × CI) and CK (1.20 × CI) chondrites. Ningqiang consists of 47.5 vol% chondrules, 2.0 vol% Ca,Al-rich inclusions (CAIs), 4.5 vol% amoeboid olivine aggregates (AOAs), and 46.0 vol% matrix. Most chondrules (95%) in Ningqiang are Mgrich. The abundances of Fe-rich and Al-rich chondrules are very low. Al-rich chondrules (ARCs) in Ningqiang are composed mainly of olivine, plagioclase, spinel, and pyroxenes. In ARCs, spinel and plagioclase are enriched in moderately volatile elements (Cr, Mn, and Na), and low-Ca pyroxenes are enriched in refractory elements (Al and Ti). The petrology and mineralogy of ARCs in Ningqiang indicate that they were formed from hybrid precursors of ferromagnesian chondrules mixed with refractory materials during chondrule formation processes. We found 294 CAIs (55.0% type A, 39.5% spinel-pyroxene-rich, 4.4% hibonite-rich, and several type C and anorthite-spinelrich inclusions) and 73 AOAs in 15 Ningqiang sections (equivalent to 20 cm2 surface area). This is the first report of hibonite-rich inclusions in Ningqiang. They are texturally similar to those in CM, CH, and CB chondrites, and exhibit three textural forms: aggregates of euhedral hibonite single crystals, fine-grained aggregates of subhedral hibonite with minor spinel, and hibonite ± Al,Ti-diopside ± spinel spherules. Evidence of secondary alteration is ubiquitous in Ningqiang. Opaque assemblages, formed by secondary alteration of pre-existing alloys on the parent body, are widespread in chondrules and matrix. On the other hand, nepheline and sodalite, existing in all chondritic components, formed by alkali-halogen metasomatism in the solar nebula.

Possible influence of dust on hurricane genesis

NASA Astrophysics Data System (ADS)

Bretl, Sebastian; Reutter, Philipp; Raible, Christoph C.; Ferrachat, Sylvaine; Lohmann, Ulrike

2014-05-01

Tropical Cyclones (TCs) belong to the most extreme events in nature. In the past decade, the possible impact of dust on Atlantic hurricanes receives growing interest. As mineral dust is able to absorb incoming solar radiation and therefore warm the surrounding air, the presence of dust can lead to a reduction of sea surface temperature (SST) and an increase in atmospheric stability. Furthermore, resulting baroclinic effects and the dry Saharan easterly jet lead to an enhanced vertical shear of the horizontal winds. SST, stability, moisture and vertical wind shear are known to potentially impact hurricane activity. But how Saharan dust influences these prerequisites for hurricane formation is not yet clear. Some dynamical mechanisms induced by the SAL might even strengthen hurricanes. An adequate framework for investigating the possible impact of dust on hurricanes is comparing high resolution simulations (~0.5°x0.5°, 31 vertical levels) with and without radiatively active dust aerosols. To accomplish this task, we are using the general circulation model ECHAM6 coupled to a modified version of the aerosol model HAM, ECHAM6-HAM-Dust. Instead of the five aerosol species HAM normally contains, the modified version takes only insoluble dust into account, but modifies the scavenging parameters in order to have a similar lifetime of dust as in the full ECHAM6-HAM. All remaining aerosols are prescribed. To evaluate the effects of dust on hurricanes, a TC detection and tracking method is applied on the results. ECHAM6-HAM-Dust was used in two configurations, one with radiatively active dust aerosols and one with dust being not radiatively active. For both set-ups, 10 Monte-Carlo simulations of the year 2005 were performed. A statistical method which identifies controlling parameters of hurricane genesis was applied on North Atlantic developing and non-developing disturbances in all simulations, comparing storms in the two sets of simulations. Hereby, dust can be assigned

Genesis of Influenza A(H5N8) Viruses

PubMed Central

El-Shesheny, Rabeh; Barman, Subrata; Feeroz, Mohammed M.; Hasan, M. Kamrul; Jones-Engel, Lisa; Franks, John; Turner, Jasmine; Seiler, Patrick; Walker, David; Friedman, Kimberly; Kercher, Lisa; Begum, Sajeda; Akhtar, Sharmin; Datta, Ashis Kumar; Krauss, Scott; Kayali, Ghazi; McKenzie, Pamela; Webby, Richard J.

2017-01-01

Highly pathogenic avian influenza A(H5N8) clade 2.3.4.4 virus emerged in 2016 and spread to Russia, Europe, and Africa. Our analysis of viruses from domestic ducks at Tanguar haor, Bangladesh, showed genetic similarities with other viruses from wild birds in central Asia, suggesting their potential role in the genesis of A(H5N8). PMID:28609260

Genesis of Influenza A(H5N8) Viruses.

PubMed

El-Shesheny, Rabeh; Barman, Subrata; Feeroz, Mohammed M; Hasan, M Kamrul; Jones-Engel, Lisa; Franks, John; Turner, Jasmine; Seiler, Patrick; Walker, David; Friedman, Kimberly; Kercher, Lisa; Begum, Sajeda; Akhtar, Sharmin; Datta, Ashis Kumar; Krauss, Scott; Kayali, Ghazi; McKenzie, Pamela; Webby, Richard J; Webster, Robert G

2017-08-01

Highly pathogenic avian influenza A(H5N8) clade 2.3.4.4 virus emerged in 2016 and spread to Russia, Europe, and Africa. Our analysis of viruses from domestic ducks at Tanguar haor, Bangladesh, showed genetic similarities with other viruses from wild birds in central Asia, suggesting their potential role in the genesis of A(H5N8).

Genesis Ultrapure Water Megasonic Wafer Spin Cleaner

NASA Technical Reports Server (NTRS)

Allton, Judith H.; Stansbery, Eileen K.; Calaway, Michael J.; Rodriquez, Melissa C.

2013-01-01

A device removes, with high precision, the majority of surface particle contamination greater than 1-micron-diameter in size from ultrapure semiconductor wafer materials containing implanted solar wind samples returned by NASA's Genesis mission. This cleaning device uses a 1.5-liter/minute flowing stream of heated ultrapure water (UPW) with 1- MHz oscillating megasonic pulse energy focused at 3 to 5 mm away from the wafer surface spinning at 1,000 to 10,000 RPM, depending on sample size. The surface particle contamination is removed by three processes: flowing UPW, megasonic cavitations, and centripetal force from the spinning wafer. The device can also dry the wafer fragment after UPW/megasonic cleaning by continuing to spin the wafer in the cleaning chamber, which is purged with flowing ultrapure nitrogen gas at 65 psi (.448 kPa). The cleaner also uses three types of vacuum chucks that can accommodate all Genesis-flown array fragments in any dimensional shape between 3 and 100 mm in diameter. A sample vacuum chuck, and the manufactured UPW/megasonic nozzle holder, replace the human deficiencies by maintaining a consistent distance between the nozzle and wafer surface as well as allowing for longer cleaning time. The 3- to 5-mm critical distance is important for the ability to remove particles by megasonic cavitations. The increased UPW sonication time and exposure to heated UPW improve the removal of 1- to 5-micron-sized particles.

Linking petrology and seismology at an active volcano.

PubMed

Saunders, Kate; Blundy, Jon; Dohmen, Ralf; Cashman, Kathy

2012-05-25

Many active volcanoes exhibit changes in seismicity, ground deformation, and gas emissions, which in some instances arise from magma movement in the crust before eruption. An enduring challenge in volcano monitoring is interpreting signs of unrest in terms of the causal subterranean magmatic processes. We examined over 300 zoned orthopyroxene crystals from the 1980-1986 eruption of Mount St. Helens that record pulsatory intrusions of new magma and volatiles into an existing larger reservoir before the eruption occurred. Diffusion chronometry applied to orthopyroxene crystal rims shows that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. These time scales are commensurate with monitoring signals at restless volcanoes, thus improving our ability to forecast volcanic eruptions by using petrology.

WRF Simulation of the Genesis of Hurricane Javier (2004) in the Eastern Pacific

NASA Technical Reports Server (NTRS)

Braun, Scott A.

2005-01-01

The Eastern Pacific has the highest frequency of genesis events per unit area of any region worldwide (Elsberry et al 1987). African easterly waves, mesoscale convective systems (MCSs), and topographic effects are thought to play roles in the genesis of tropical cyclones there (Frank and Clark 1980, Velasco and Fritsch 1987, Zehnder 1991, Zehnder and Gall 1991; Farfan and Zehnder 1997). Mozer and Zehnder (1996), using dry, idealized simulations of flow past a large-scale three-dimensional mountain range comparable to the Sierra Madre Mountains of Mexico, showed that upstream flow blocking led to diversion of the flow primarily to the south of the mountains. This flow diversion led to the formation of a low-level, barotropically unstable jet (at a location comparable to the Isthmus of Tehuantepec) and the continuous formation of synoptic-scale vorticity maxima, which they suggested may play a role in tropical cyclogenesis. Farfan and Zehnder (1 997) examined the synoptic-scale circulations that led to the formation of Hurricane Guillermo (1991). Using numerical simulations, they found that flow blocking led to the formation of a low-level easterly jet south of the mountains of Central America and a northeasterly (gap flow) jet over the Gulf of Tehuantepec, which combined with the flow associated with the Intertropical Convergence Zone (ITCZ) to produce a closed cyclonic circulation in the location of Guillermo s formation. As will be discussed in this paper, the evolution of the flow field that was associated with the genesis of Hurricane Javier was similar to that described in Farfan and Zehnder (1997), with well-defined topographic flow features. Here, using a high- resolution simulation with the WRF model, we investigate whether these topographically induced flows played a significant role in the genesis of Javier.

Spinel cataclasites in 15445 and 72435 - Petrology and criteria for equilibrium

NASA Technical Reports Server (NTRS)

Baker, M. B.; Herzberg, C. T.

1980-01-01

The problem of establishing the existence of equilibrium among the coexisting phases in the rock is addressed by presenting petrographic and mineral chemistry data on a new spinel cataclasite from 15445 (clast H) and data more extensive than those previously available on two clasts in 72435. Criteria useful in reconstructing the original petrology of these and other spinel cataclasites are analyzed by considering equilibrium among the different phases, that is, the mono- or polymict nature of these cataclasized samples. Finally, the role of impact processes in disturbing the equilibria is discussed.

Tumour genesis syndrome: severe hypophosphatemia and hypokalemia may be ominous presenting findings in childhood acute myeloid leukaemia.

PubMed

Chan, Winnie Ky; Chang, Kai On; Lau, Wing Hung

2017-08-01

We report a 16-year-old girl who was diagnosed with acute leukaemia and a marked leucocytosis >200 × 10 9 /L. She presented with marked hypophosphatemia, hypokalemia, acute renal failure and acute respiratory failure. These electrolytes disturbances may indicate rapid tumour genesis. These ominous findings required urgent treatment to halt the crises of rapid leukemic cell proliferation. Mark hypophosphatemia and hypokalemia may be presenting electrolyte abnormalities in a patient with acute leukaemia, and these may be indicators of aggressive tumour genesis. What is known: • Mild electrolyte disturbances are common in oncology patients • Tumour lysis syndrome is well recognized by paediatriaticians What is new: • Life-threatening hypophosphatemia is an uncommon presentation • These electrolytes disorders may indicate an aggressive tumour genesis process even at presentation and require urgent treatment.

Distribution of terrestrial age and petrologic type of meteorites from western Libya

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

Jull, A.J.T.; Donahue, D.J.; Wlotzka, F.

1990-10-01

A group of 54 meteorites have been recovered from Daraj, Western Libya. After assessment of pairing of samples, using petrologic criteria, {sup 14}C terrestrial ages were obtained on 13 samples selected from 9 different fall events. Eleven of the ages range from 3,500 to 7,600 years, with only two samples having ages in excess of 10,000 years. The cut-off in ages may be related to the timing of climatic changes in the Hammadah al Hamra.

Quantitative EPMA Compositional Mapping of NWA 2995: Characterization, and Petrologic Interpretation of Mafic Clasts

NASA Technical Reports Server (NTRS)

Carpenter, P. K.; Hahn, T. M.; Korotev, R. L.; Ziegler, R. A.; Jolliff, B. L.

2017-01-01

We present the first fully quantitative compositional maps of lunar meteorite NWA 2995 using electron microprobe stage mapping, and compare selected clast mineralogy and chemistry. NWA 2995 is a feldspathic fragmental breccia containing numerous highland fine grained lithologies, including anorthosite, norite, olivine basalt, subophitic basalt, gabbro, KREEP-like basalt, granulitic and glassy impact melts, coarse-grained mineral fragments, Fe-Ni metal, and glassy matrix [1]. Chips of NWA 2995, representing these diverse materials, were analyzed by INAA and fused-bead electron-probe microanalysis (EPMA); comparison of analytical data suggests grouping of lunar meteorites NWA 2995, 2996, 3190, 4503, 5151, and 5152. The mean composition of NWA 2995 corresponds to a 2:1 mixture of feldspathic and mare material, with approximately 5% KREEP component [2]. Clast mineral chemistry and petrologic interpretation of paired stone NWA 2996 has been reported by Mercer et al. [3], and Gross et al. [4]. This study combines advances in quantitative EPMA compositional mapping and data analysis, as applied to selected mafic clasts in a polished section of NWA 2995, to investigate the origin of mafic lithic components and to demonstrate a procedural framework for petrologic analysis.

Bases of the Mantle-Carbonatite Conception of Diamond Genesis

NASA Astrophysics Data System (ADS)

Litvin, Yuriy; Spivak, Anna; Kuzyura, Anastasia

2016-04-01

In the mantle-carbonatite conception of diamond genesis, the results of physic-chemical experiments are coordinated with the data of analytic mineralogy of primary inclusions in natural diamonds. Generalization of the solutions of principal genetic problems constitutes the bases of the conception. The solutions are following: (1) it is grounded that diamond-parental melts of the upper mantle have peridotite/eclogite - carbonatite - carbon compositions, of the transition zone - (wadsleite↔ringwoodite) - majorite - stishovite - carbonatite - carbon compositions, and of the lower mantle - periclase/wustite - bridgmanite - Ca-perovskite -stishovite - carbonatite - carbon compositions; (2) a construction of generalized diagrams for the diamond-parental media, which reveal changeable compositions of the growth melts of diamonds and associated phases, their genetic relations to the mantle substance, and classification connections of the primary inclusions in natural diamonds; (3) experimental equilibrium phase diagrams of syngenesis of diamonds and primary inclusions, which characterize the nucleation and growth conditions of diamonds and a capture of paragenetic and xenogenetic minerals by the growing diamonds; (4) a determination of the phase diagrams of diamonds and inclusions syngenesis under the regime of fractional crystallization, which discover the regularities of ultrabasic-basic evolution and paragenesis transitions in the diamond-forming systems of the upper and lower mantle. The evidence of the physic-chemically united mode of diamond genesis at the mantle depths with different mineralogy is obtained. References. Litvin Yu.A. (2007). High-pressure mineralogy of diamond genesis. In: Advances in High-Pressure Mineralogy (edited by Eiji Ohtani), Geological Society of America Special paper 421, 83-103. Litvin Yu.A. (2012). Experimental study of physic-chemical conditions of natural diamond formation on an example of the eclogite

Using a Differential Scanning Calorimeter to Teach Phase Equilibria to Students of Igneous and Metamorphic Petrology

ERIC Educational Resources Information Center

Maria, Anton H.; Millam, Evan L.; Wright, Carrie L.

2011-01-01

As an aid for teaching phase equilibria to undergraduate students of igneous and metamorphic petrology, we have designed a laboratory exercise that allows them to create a phase diagram from data produced by differential scanning calorimetry. By preparing and analyzing samples of naphthalene and phenanthrene, students acquire hands-on insight into…

Magma genesis, storage and eruption processes at Aluto volcano, Ethiopia: lessons from remote sensing, gas emissions and geochemistry

NASA Astrophysics Data System (ADS)

Hutchison, William; Biggs, Juliet; Mather, Tamsin; Pyle, David; Gleeson, Matthew; Lewi, Elias; Yirgu, Gezahgen; Caliro, Stefano; Chiodini, Giovanni; Fischer, Tobias

2016-04-01

One of the most intriguing aspects of magmatism during the transition from continental rifting to sea-floor spreading is that large silicic magmatic systems develop within the rift zone. In the Main Ethiopian Rift (MER) these silicic volcanoes not only pose a significant hazard to local populations but they also sustain major geothermal resources. Understanding the journey magma takes from source to surface beneath these volcanoes is vital for determining its eruption style and for better evaluating the geothermal resources that these complexes host. We investigate Aluto, a restless silicic volcano in the MER, and combine a wide range of geochemical and geophysical techniques to constrain magma genesis, storage and eruption processes and shed light on magmatic-hydrothermal-tectonic interactions. Magma genesis and storage processes at Aluto were evaluated using new whole-rock geochemical data from recent eruptive products. Geochemical modelling confirms that Aluto's peralkaline rhyolites, that constitute the bulk of recent erupted products, are generated from protracted fractionation (>80 %) of basalt that is compositionally similar to rift-related basalts found on the margins of the complex. Crustal melting did not play a significant role in rhyolite genesis and melt storage depths of ~5 km can reproduce almost all aspects of their geochemistry. InSAR methods were then used to investigate magma storage and fluid movement at Aluto during an episode of ground deformation that took place between 2008 and 2010. Combining new SAR imagery from different viewing geometries we identified an accelerating uplift pulse and found that source models support depths of magmatic and/or fluid intrusion at ~5 km for the uplift and shallower depths of ~4 km for the subsidence. Finally, gas samples collected on Aluto in 2014 were used to evaluate magma and fluid transport processes. Our results show that gases are predominantly emanating from major fault zones on Aluto and that they

Subduction of Proterozoic to Late Triassic continental basement in the Guatemala suture zone: A petrological and geochronological study of high-pressure metagranitoids from the Chuacús complex

NASA Astrophysics Data System (ADS)

Maldonado, Roberto; Ortega-Gutiérrez, Fernando; Ortíz-Joya, Guillermo A.

2018-05-01

Many continental subduction complexes contain abundant granitic rocks coexisting with minor volumes of eclogite-facies rocks. Characterization of granitic protoliths is crucial to decipher the origin of subducted continental crust, whereas knowledge of its metamorphic evolution is required to constrain the mechanisms of burial and exhumation. In this work we present geochronological and petrological evidence that demonstrate the occurrence of a subducted Proterozoic to Late Triassic granitic basement in the Chuacús complex of central Guatemala. Metagranitoids exposed in this area are interlayered with eclogite and other high-pressure rocks, and their structure is considerably variable due to strain partitioning during deformation. Laser ablation-inductively coupled plasma-mass spectrometry U-Pb zircon data from two ferroan metagranites yield protolith crystallization ages of ca. 1.1 Ga and their trace-element abundances suggest an origin related to intraplate magmatism, while a high-silica, peraluminous metagranite is dated at 1.0 Ga and was probably originated by partial melting of a high-grade continental crust. On the other hand, two megacrystic to augen metagranitoids yield protolith crystallization ages of ca. 224 Ma, which are identical within errors to the protolith age of hosted eclogitic metabasites. Their high incompatible trace element abundances together with the observed spatial-temporal relationships with mafic protoliths suggest that Late Triassic bimodal magmatism in the Chuacús complex was probably originated in a within-plate setting. Regardless of their age or structure, the studied metagranites preserve evidences for high-pressure metamorphic equilibration, such as the occurrence of Ca-rich garnet (XCa up to 0.52) in association with phengite (Si contents of up to 3.4 pfu) and rutile. The integration of Zr-in-rutile thermometry and phengite barometry allows the peak metamorphic conditions to be constrained at 640-680 °C and 13 kbar. This

Public Risk Assessment of Off-Nominal Genesis Entries

NASA Technical Reports Server (NTRS)

Mendeck, Gavin F.; Kadwa, Binaifer

2006-01-01

Public risk estimations were among the preparations for the entry of the Genesis sample return capsule. Personnel at the Johnson Space Center were requested to provide estimates of the public risk of off-nominal entries. These scenarios dealt with an incomplete trajectory maneuver that would result in the capsule landing outside of the controlled Utah Test and Training Range. Using a conservative approach to the inputs and assumptions, such off-nominal entries were demonstrated to fall within the project risk limits.

The genesis of craniofacial biology as a health science discipline.

PubMed

Sperber, G H; Sperber, S M

2014-06-01

The craniofacial complex encapsulates the brain and contains the organs for key functions of the body, including sight, hearing and balance, smell, taste, respiration and mastication. All these systems are intimately integrated within the head. The combination of these diverse systems into a new field was dictated by the dental profession's desire for a research branch of basic science devoted and attuned to its specific needs. The traditional subjects of genetics, embryology, anatomy, physiology, biochemistry, dental materials, odontology, molecular biology and palaeoanthropology pertaining to dentistry have been drawn together by many newly emerging technologies. These new technologies include gene sequencing, CAT scanning, MRI imaging, laser scanning, image analysis, ultrasonography, spectroscopy and visualosonics. A vibrant unitary discipline of investigation, craniofacial biology, has emerged that builds on the original concept of 'oral biology' that began in the 1960s. This paper reviews some of the developments that have led to the genesis of craniofacial biology as a fully-fledged health science discipline of significance in the advancement of clinical dental practice. Some of the key figures and milestones in craniofacial biology are identified. © 2014 Australian Dental Association.

Initial Subdivision of Genesis Early Science Polished Aluminum Collector

NASA Technical Reports Server (NTRS)

Allton, J. H.; Stansbery, E. K.; McNamara, K. M.; Meshik, A.; See, T. H.; Bastien, R.

2005-01-01

A large surface, about 245 square centimeters, of highly polished aluminum 6061 T6 alloy was attached to the science canister thermal panel for the purpose of collecting solar wind noble gases. The analysis of this collector will be part of the Genesis Early Science results. The pre-launch configuration of the collector is shown. The collector sustained some damage during the recovery impact in Utah, September 8, 2004.

Genesis: Sorting Out the Pieces

NASA Technical Reports Server (NTRS)

McNamara, K. M.; Westphal, Andrew; Butterworth, A. L.; Burnett, D. S.

2005-01-01

The Genesis mission returned to Earth on September 8, 2004, experiencing a non-nominal reentry. The parachutes which were supposed to slow and stabilize the capsule throughout the return failed to deploy, causing the capsule to impact the desert floor at a speed of nearly 200 MPH. The result is that instead of receiving 301 intact solar wind collectors, mission personnel recovered and documented more than 10,000 collector fragments. Most of the fragments were pieces of the collector arrays but were not recovered on their original array locations. These were classified by size (longest dimension), identity (sometimes a guess) and found location (when known). The work took more than one month in Utah, and details are discussed elsewhere[1] The samples were transferred to their permanent home at the Johnson Space Center on October 4, 2004.

Mineralogy, Petrology, Chronology, and Exposure History of the Chelyabinsk Meteorite and Parent Body

NASA Technical Reports Server (NTRS)

Righter, K.; Abell, P.; Agresti, D.; Berger, E. L.; Burton, A. S.; Delaney, J. S.; Fries, M. D.; Gibson, E. K.; Harrington, R.; Herzog, G. F.;

Composition and Petrology of HED Polymict Breccias: The Regolith of (4) Vesta

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.; Cartwright, J. A.; Herrin, J. S.; Mertzman, S. A.; Mertzman, K. R.; Peng, Z. X.; Quinn, J. E.

2012-01-01

The polymict breccias of the howardite, eucrite and diogenite (HED) clan of meteorites preserve records of regolith processes that occur on Vesta, their putative home world. These breccias -- howardites, polymict eucrites and polymict diogenites -- are impact-engendered mixtures of diogenites and eucrites. The compositions of polymict breccias can be used to constrain the lithologic diversity of the vestan crust and the excavation depths of these materials. We have done petrological and compositional studies of multiple samples of 5 polymict eucrites and 28 howardites to investigate these issues. Older analyses were done on samples of approx 0.5 gram mass by INAA; newer analyses on samples of approx 5 gram mass by XRF and ICP-MS. We estimate the percentage of eucritic material (POEM) of polymict breccias by comparing their Al and/or Ca contents to those of average basaltic eucrite and diogenite. Our samples have POEM ranging from 28 to 98; adding two polymict diogenites from extends the range to POEM 10. One hypothesis is that ancient, well-mixed vestan regolith has POEM approx 67 and has a higher content of admixed impactor material. Several of our howardites have POEM of 59-74 (Al and/or Ca contents +/- 10% of POEM 67); about a third have Ni contents >300 micro g/g suggesting they contain >2% chondritic material (CM and/or CR). These may be regolithic howardites. Only one (LEW 85313) contains Ne dominated by a solar wind (SW) component. PCA 02066 is dominated by impact-melt material of polymict parentage and petrologically appears to be a mature regolith breccia, yet it does not contain SW-Ne. GRO 95602 falls within the POEM window, contains SW-Ne], yet has a Ni content of 193 micro g/g. Its petrologic characteristics suggest it was formed from immature regolith (no polymict breccia clasts; no glass). Trace element characteristics of the polymict breccias demonstrate the dominance of main-group eucrites as the basaltic component. Mixing diagrams of Zr, Nb, Ba, Hf

Large-scale influences on the pre-genesis of tropical cyclone Karl (2010)

NASA Astrophysics Data System (ADS)

Griffin, Kyle S.

The genesis of Tropical Cyclone (TC) Karl (2010) in September 2010 provided a unique opportunity to examine the continuing problem of understanding tropical cyclogenesis. The precursor disturbance to Karl originated from a cluster of showers east of the Windward Islands and was well sampled by ongoing field campaigns, particularly the PRE-Depression Investigation of Cloud-systems in the Tropics (PREDICT), as the targeted disturbance progressed westward. While traditional genesis theories focusing on moisture and mass fields (e.g. top-down showerhead method) can explain the initial spin-up of the disturbance several days prior to its official genesis, additional perspectives are examined in concert with more traditional methods in order to provide a more complete analysis of the synoptic-scale patterns that influenced the pre-Karl disturbance. A surge of westerly winds from northern South America aids the initial spin-up of the pre-Karl disturbance on 8-9 September, leading to the formation of a nearly closed earth-relative circulation. It can be shown that these anomalous westerly winds are tied to the convectively active phase of a convectively coupled Kelvin wave (CCKW). The observed formation of the nearly closed circulation on 10 September is well timed with the passage of this convectively active phase, a relationship that has been shown to hold true in cases of CCKW-TC interactions around the globe. Physically, the CCKW increases deep convection and aids in the generation of low-level relative vorticity on the cyclonic shear side of the low-level westerly wind anomalies, both of which serve to help organize the pre-Karl disturbance. Finally, the passage of the CCKW coincides with an equatorward surge of cold air and southerly winds in the lee of the Andes, triggered by a passing mid-latitude disturbance on 31 August. As the surge passes the equator on 7 September, little temperature perturbation remains with the surge, but terrain-channeled low-level flow

The Magmatic Structure of Mid-ocean Ridges: Integrating Geophysical and Petrological Observations

NASA Astrophysics Data System (ADS)

Maclennan, J.; Singh, S.

Geophysical surveys, petrological observations and numerical models have all played an important role in the study of magmatic processes at mid-ocean ridges. However, few studies have attempted to integrate the constraints from both geophysical and geochemical observations in order to develop models of mid-ocean ridges. Composi- tional variation within the oceanic crust must be considered when geophysical models are interpreted in terms of variation in temperature or fluid fraction. Modellers com- monly assume that the crust is compositionally homogeneous and that the relationship between temperature and melt fraction does not vary within the crust. However, the compositions of oceanic crustal rocks collected from the Oman ophiolite vary widely and their predicted solidus temperatures vary from 990­1240C and their liquidus temperatures from 1250­1700C. Compositional variation within the solid part of the oceanic crust causes variation in seismic velocities. At fixed temperature and pressure the compositional variation present in crustal rocks can give P-wave velocity variation of 1 km s-1 or more. This has the same effect as a temperature variation of 1500C in the solid or of a variation of 20% in the melt fraction. The importance of this petrolog- ical framework for the interpretation of the seismic structure of mid-ocean ridges and for the development of thermal models of oceanic crustal accretion is demonstrated using an example from the East Pacific Rise near 9N.

Origin of New Faculty in Sedimentary Petrology at Ph.D.-Granting Universities in the United States and Canada.

ERIC Educational Resources Information Center

Thornton, Scott E.

1981-01-01

To aid prospective graduate students in sedimentary petrology who wish to teach at colleges or universities, 121 doctoral graduates in this field are traced to their present appointments in higher education. Only 31 percent of these graduates attained this career goal. (Author/WB)

Molecular Substrate Alteration by Solar Wind Radiation Documented on Flown Genesis Mission Array Materials

NASA Technical Reports Server (NTRS)

Calaway, Michael J.; Stansbery, Eileen K.

2006-01-01

The Genesis spacecraft sampling arrays were exposed to various regimes of solar wind during flight that included: 313.01 days of high-speed wind from coronal holes, 335.19 days of low-speed inter-stream wind, 191.79 days of coronal mass ejections, and 852.83 days of bulk solar wind at Lagrange 1 orbit. Ellipsometry measurements taken at NASA s Johnson Space Center show that all nine flown array materials from the four Genesis regimes have been altered by solar wind exposure during flight. These measurements show significant changes in the optical constant for all nine ultra-pure materials that flew on Genesis when compared with their non-flight material standard. This change in the optical constant (n and k) of the material suggests that the molecular structure of the all nine ultra-pure materials have been altered by solar radiation. In addition, 50 samples of float-zone and czochralski silicon bulk array ellipsometry results were modeled with an effective medium approximation layer (EMA substrate layer) revealing a solar radiation molecular damage zone depth below the SiO2 native oxide layer ranging from 392 to 613 . This bulk solar wind radiation penetration depth is comparable to the depth of solar wind implantation depth of Mg measured by SIMS and SARISA.

Petrologic evolution of the Caetano magmatic system: What can we learn from a dissected, 34 Ma caldera in the northern Great Basin, western U.S.A.?

NASA Astrophysics Data System (ADS)

Watts, K. E.; Colgan, J. P.; John, D. A.; Henry, C. D.

2012-12-01

depths of ~14-15 km. In light of our new petrologic data, we highlight the following key points: (1) Diverse crystal cargoes, disequilibrium textures, and wide compositional oscillations in single phenocrysts and among discrete mineral populations indicate prolonged and complex episodes of magma assembly and growth. Based on zircon U-Pb SHRIMP ages that range from ~34-37 Ma, assembly and growth may have spanned ~2-3 Ma, or a 34 Ma Caetano magma chamber may have assimilated older igneous rocks in and around the caldera. (2) Mineral chemistry, U-Pb and Ar-Ar geochronology, O isotope geochemistry, and whole rock major and trace element geochemistry indicate a genetic connection between the Caetano Tuff and resurgent granitic plutons, supporting the role of linked volcanic-plutonic components in caldera settings. (3) Generation and eruption of crystal-rich "monotonous" rhyolite calls into question the prevailing paradigms of crystal-poor rhyolites derived from crystal mushes, or crystal-rich "monotonous intermediates" derived from homogeneous dacitic magma reservoirs. The Caetano Tuff may be a representative end member of caldera-forming eruptions that is important for understanding large-volume rhyolite genesis in the shallow-middle crust.

Lunar basalt meteorite EET 87521: Petrology of the clast population

NASA Technical Reports Server (NTRS)

Semenova, A. S.; Nazarov, M. A.; Kononkova, N. N.

1993-01-01

The Elephant Moraine meteorite EET 87521 was classified as a lunar mare basalt breccia which is composed mainly of VLT basalt clasts. Here we report on our petrological study of lithic clasts and monomineralic fragments in the thin sections EET 87521,54 and EET 87521,47,1, which were prepared from the meteorite. The results of the study show that EET 87521 consists mainly of Al-rich ferrobasalt clasts and olivine pyroxenite clasts. The bulk composition of the meteorite can be well modelled by the mixing of these lithic components which appear to be differentiates of the Luna 25 basalt melt. KREEP and Mg-rich gabbro components are minor constituents of EET 87521.

The Private Lives of Minerals: Social Network Analysis Applied to Mineralogy and Petrology

NASA Astrophysics Data System (ADS)

Hazen, R. M.; Morrison, S. M.; Fox, P. A.; Golden, J. J.; Downs, R. T.; Eleish, A.; Prabhu, A.; Li, C.; Liu, C.

2016-12-01

Comprehensive databases of mineral species (rruff.info/ima) and their geographic localities and co-existing mineral assemblages (mindat.org) reveal patterns of mineral association and distribution that mimic social networks, as commonly applied to such varied topics as social media interactions, the spread of disease, terrorism networks, and research collaborations. Applying social network analysis (SNA) to common assemblages of rock-forming igneous and regional metamorphic mineral species, we find patterns of cohesion, segregation, density, and cliques that are similar to those of human social networks. These patterns highlight classic trends in lithologic evolution and are illustrated with sociograms, in which mineral species are the "nodes" and co-existing species form "links." Filters based on chemistry, age, structural group, and other parameters highlight visually both familiar and new aspects of mineralogy and petrology. We quantify sociograms with SNA metrics, including connectivity (based on the frequency of co-occurrence of mineral pairs), homophily (the extent to which co-existing mineral species share compositional and other characteristics), network closure (based on the degree of network interconnectivity), and segmentation (as revealed by isolated "cliques" of mineral species). Exploitation of large and growing mineral data resources with SNA offers promising avenues for discovering previously hidden trends in mineral diversity-distribution systematics, as well as providing new pedagogical approaches to teaching mineralogy and petrology.

The instrumental genesis process in future primary teachers using Dynamic Geometry Software

NASA Astrophysics Data System (ADS)

Ruiz-López, Natalia

2018-05-01

This paper, which describes a study undertaken with pairs of future primary teachers using GeoGebra software to solve geometry problems, includes a brief literature review, the theoretical framework and methodology used. An analysis of the instrumental genesis process for a pair participating in the case study is also provided. This analysis addresses the techniques and types of dragging used, the obstacles to learning encountered, a description of the interaction between the pair and their interaction with the teacher, and the type of language used. Based on this analysis, possibilities and limitations of the instrumental genesis process are identified for the development of geometric competencies such as conjecture creation, property checking and problem researching. It is also suggested that the methodology used in the analysis of the problem solving process may be useful for those teachers and researchers who want to integrate Dynamic Geometry Software (DGS) in their classrooms.

Scale-invariant fluctuations from Galilean genesis

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

Wang, Yi; Brandenberger, Robert, E-mail: wangyi@physics.mcgill.ca, E-mail: rhb@physics.mcgill.ca

2012-10-01

We study the spectrum of cosmological fluctuations in scenarios such as Galilean Genesis \\cite(Nicolis) in which a spectator scalar field acquires a scale-invariant spectrum of perturbations during an early phase which asymptotes in the far past to Minkowski space-time. In the case of minimal coupling to gravity and standard scalar field Lagrangian, the induced curvature fluctuations depend quadratically on the spectator field and are hence non-scale-invariant and highly non-Gaussian. We show that if higher dimensional operators (the same operators that lead to the η-problem for inflation) are considered, a linear coupling between background and spectator field fluctuations is induced whichmore » leads to scale-invariant and Gaussian curvature fluctuations.« less

Depth profiling analysis of solar wind helium collected in diamond-like carbon film from Genesis

DOE PAGES

Bajo, Ken-ichi; Olinger, Chad T.; Jurewicz, Amy J.G.; ...

2015-01-01

The distribution of solar-wind ions in Genesis mission collectors, as determined by depth profiling analysis, constrains the physics of ion solid interactions involving the solar wind. Thus, they provide an experimental basis for revealing ancient solar activities represented by solar-wind implants in natural samples. We measured the first depth profile of ⁴He in a collector; the shallow implantation (peaking at <20 nm) required us to use sputtered neutral mass spectrometry with post-photoionization by a strong field. The solar wind He fluence calculated using depth profiling is ~8.5 x 10¹⁴ cm⁻². The shape of the solar wind ⁴He depth profile ismore » consistent with TRIM simulations using the observed ⁴He velocity distribution during the Genesis mission. It is therefore likely that all solar-wind elements heavier than H are completely intact in this Genesis collector and, consequently, the solar particle energy distributions for each element can be calculated from their depth profiles. Ancient solar activities and space weathering of solar system objects could be quantitatively reproduced by solar particle implantation profiles.« less

ALTERED RA SIGNALING IN THE GENESIS OF ETHANOL-INDUCED LIMB DEFECTS

EPA Science Inventory

Altered RA Signaling in the Genesis of Ethanol-Induced Limb Defects

Johnson CS(1), Sulik KK(1,2) Hunter, ES III(3)
(1) Dept of Cell and Developmental Biology, UNC-Chapel Hill (2) Bowles Center for Alcohol Studies, UNC-CH (3) NHEERL, ORD, US EPA, RTP, NC

Administr...

GENESIS 1.1: A hybrid-parallel molecular dynamics simulator with enhanced sampling algorithms on multiple computational platforms.

PubMed

Kobayashi, Chigusa; Jung, Jaewoon; Matsunaga, Yasuhiro; Mori, Takaharu; Ando, Tadashi; Tamura, Koichi; Kamiya, Motoshi; Sugita, Yuji

2017-09-30

GENeralized-Ensemble SImulation System (GENESIS) is a software package for molecular dynamics (MD) simulation of biological systems. It is designed to extend limitations in system size and accessible time scale by adopting highly parallelized schemes and enhanced conformational sampling algorithms. In this new version, GENESIS 1.1, new functions and advanced algorithms have been added. The all-atom and coarse-grained potential energy functions used in AMBER and GROMACS packages now become available in addition to CHARMM energy functions. The performance of MD simulations has been greatly improved by further optimization, multiple time-step integration, and hybrid (CPU + GPU) computing. The string method and replica-exchange umbrella sampling with flexible collective variable choice are used for finding the minimum free-energy pathway and obtaining free-energy profiles for conformational changes of a macromolecule. These new features increase the usefulness and power of GENESIS for modeling and simulation in biological research. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Research in volcanic geology, petrology and planetary science at MIT, 1969 to 1974

NASA Technical Reports Server (NTRS)

Mcgetchin, T. R.

1974-01-01

The behavior of volcanoes was studied by geologic mapping, petrologic investigations of lava and xenoliths, physical measurements, and theoretical modelling. Field observations were conducted in Alaska (Nunivak Island), Iceland, Hawaii (Mauna Kea), Italy (Etna, Stromboli), and Arizona. The results are discussed and compared with known data for lunar and planetary gelogy. Field methods used for the volcano research are cited and a list is given of all participating scientists and students. Publications and abstracts resulting from the research are also listed.

Education in the Knowledge Society: Genesis of Concept and Reality

ERIC Educational Resources Information Center

Karpov, Alexander O.

2016-01-01

The aim of the article is to define the content of theoretical ideas about education in the knowledge society in terms of the birth of its social reality. It is shown that the genesis of the concept of education in the knowledge society goes back to the period of 1950-1960s and is due to the emergence of new qualities of an industrial worker that…

Cleaning Surface Particle Contamination with Ultrapure Water (UPW) Megasonic Flow on Genesis Array Collectors

NASA Technical Reports Server (NTRS)

Allton, J. H.; Calaway, Michael J.; Hittle, J. D.; Rodriquez, M. C.; Stansbery, E. K.; McNamara, K. M.

2006-01-01

The hard landing experienced by the Genesis sample return capsule breached the science canister containing the solar wind collectors. This impact into the damp lakebed contaminated collector surfaces with pulverized collector and spacecraft materials and Utah sediment and brine residue. The gold foil, polished aluminum, and bulk metallic glass remained intact, but the solar wind bulk and regime-specific array collectors were jarred loose from their frames and fractured into greater than 10,000 specimens. After a year of investigation and cleaning experimentation, the Genesis Science Team determined that array collectors had 4 classes of contaminants: particles, molecular film, submicron inorganic particulate ("aerosol"), and pre-launch surface contamination. We discuss here use of megasonically energized ultrapure water (UPW) for removing particulate debris from array collector fragments.

Taking an Instrumental Genesis Lens: New Insights into Collaborative Mobile Learning

ERIC Educational Resources Information Center

Cerratto Pargman, Teresa; Nouri, Jalal; Milrad, Marcelo

2018-01-01

In this paper, we argue that in order to gain a deeper understanding of collaborative mobile learning in schools, it is important to know not only how mobile devices affect collaborative learning but also how collaborative learning emerges and is mediated by these devices. We develop our argument by applying the instrumental genesis theory and the…

Laser Subdivision of the Genesis Concentrator Target Sample 60000

NASA Technical Reports Server (NTRS)

Lauer, Howard V., Jr.; Burkett, P. J.; Rodriquez, M. C.; Nakamura-Messenger, K.; Clemett, S. J.; Gonzales, C. P.; Allton, J. H.; McNamara, K. M.; See, T. H.

2013-01-01

The Genesis Allocation Committee received a request for 1 square centimeter of the diamond-like-carbon (DLC) concentrator target for the analysis of solar wind nitrogen isotopes. The target consists of a single crystal float zone (FZ) silicon substrate having a thickness on the order of 550 micrometers with a 1.5-3.0 micrometer-thick coating of DLC on the exposed surface. The solar wind is implanted shallowly in the front side DLC. The original target was a circular quadrant with a radius of 3.1 cm; however, the piece did not survive intact when the spacecraft suffered an anomalous landing upon returning to Earth on September 8, 2004. An estimated 75% of the DLC target was recovered in at least 18 fragments. The largest fragment, Genesis sample 60000, has been designated for this allocation and is the first sample to be subdivided using our laser scribing system Laser subdivision has associated risks including thermal diffusion of the implant if heating occurs and unintended breakage during cleavage. A careful detailed study and considerable subdividing practice using non-flight FZ diamond on silicon, DOS, wafers has considerably reduced the risk of unplanned breakage during the cleaving process. In addition, backside scribing reduces the risk of possible thermal excursions affecting the implanted solar wind, implanted shallowly in the front side DLC.

NR2A contributes to genesis and propagation of cortical spreading depression in rats.

PubMed

Bu, Fan; Du, Ruoxing; Li, Yi; Quinn, John P; Wang, Minyan

2016-03-22

Cortical spreading depression (CSD) is a transient propagating excitation of synaptic activity followed by depression, which is implicated in migraine. Increasing evidence points to an essential role of NR2A-containing NMDA receptors in CSD propagation in vitro; however, whether these receptors mediate CSD genesis in vivo requires clarification and the role of NR2A on CSD propagation is still under debate. Using in vivo CSD in rats with electrophysiology and in vitro CSD in chick retina with intrinsic optical imaging, we addressed the role of NR2A in CSD. We demonstrated that NVP-AAM077, a potent antagonist for NR2A-containing receptors, perfused through microdialysis probes, markedly reduced cortex susceptibility to CSD, but also reduced magnitude of CSD genesis in rats. Additionally, NVP-AAM077 at 0.3 nmol perfused into the contralateral ventricle, considerably suppressed the magnitude of CSD propagation wave and propagation rate in rats. This reduction in CSD propagation was also observed with TCN-201, a negative allosteric modulator selective for NR2A, at 3 μM, in the chick retina. Our data provides strong evidence that NR2A subunit contributes to CSD genesis and propagation, suggesting drugs selectively antagonizing NR2A-containing receptors might constitute a highly specific strategy treating CSD associated migraine with a likely better safety profile.

NR2A contributes to genesis and propagation of cortical spreading depression in rats

PubMed Central

Bu, Fan; Du, Ruoxing; Li, Yi; Quinn, John P; Wang, Minyan

2016-01-01

Cortical spreading depression (CSD) is a transient propagating excitation of synaptic activity followed by depression, which is implicated in migraine. Increasing evidence points to an essential role of NR2A-containing NMDA receptors in CSD propagation in vitro; however, whether these receptors mediate CSD genesis in vivo requires clarification and the role of NR2A on CSD propagation is still under debate. Using in vivo CSD in rats with electrophysiology and in vitro CSD in chick retina with intrinsic optical imaging, we addressed the role of NR2A in CSD. We demonstrated that NVP-AAM077, a potent antagonist for NR2A-containing receptors, perfused through microdialysis probes, markedly reduced cortex susceptibility to CSD, but also reduced magnitude of CSD genesis in rats. Additionally, NVP-AAM077 at 0.3 nmol perfused into the contralateral ventricle, considerably suppressed the magnitude of CSD propagation wave and propagation rate in rats. This reduction in CSD propagation was also observed with TCN-201, a negative allosteric modulator selective for NR2A, at 3 μM, in the chick retina. Our data provides strong evidence that NR2A subunit contributes to CSD genesis and propagation, suggesting drugs selectively antagonizing NR2A-containing receptors might constitute a highly specific strategy treating CSD associated migraine with a likely better safety profile. PMID:27001011

Genesis: Removing Contamination from Sample Collectors

NASA Technical Reports Server (NTRS)

Lauer, H. V.; McNamara, K. M.; Westphal, Andrew; Butterworth, A. L.; Burnett, D. S.; Jurewicz, A.; Woolum, D.; Allton, J. H.

2005-01-01

The Genesis mission returned to Earth on September 8, 2004, experiencing a non-nominal reentry. The parachutes which were supposed to slow and stabilize the capsule throughout the return failed to deploy, causing the capsule to impact the desert floor at a speed of nearly 200 MPH. Both the science canister and the major components of the SRC were returned before nightfall on September 8 to the prestaged cleanroom at UTTR , avoiding prolonged exposure or pending weather changes which might further contaminate the samples. The majority of the contaminants introduced as a result of the anomalous landing were in the form of particulates, including UTTR dust and soil, carbon-carbon heat shield material, and shattered collector dust (primarily silicon and germanium). Additional information is included in the original extended abstract.

Multi-element RIMS Analysis of Genesis Solar Wind Collectors

NASA Astrophysics Data System (ADS)

Veryovkin, I. V.; Tripa, C. E.; Zinovev, A. V.; King, B. V.; Pellin, M. J.; Burnett, D. S.

2009-12-01

The samples of Solar Wind (SW) delivered by the NASA Genesis mission, present significant challenges for surface analytical techniques, in part due to severe terrestrial contamination of the samples on reentry, in part due to the ultra-shallow and diffused ion implants in the SW collector materials. We are performing measurements of metallic elements in the Genesis collectors using Resonance Ionization Mass Spectrometry (RIMS), an ultra-sensitive analytical method capable of detecting SW in samples with lateral dimensions of only a few mm and at concentrations from above one ppm to below one ppt. Since our last report at 2008 AGU Fall Meeting, we have (a) developed and tested new resonance ionization schemes permitting simultaneous measurements of up to three (Ca, Cr, and Mg) elements, and (b) improved reproducibility and accuracy of our RIMS analyses for SW-like samples (i.e. shallow ion implants) by developing and implementing an optimized set of new analytical protocols. This is important since the quality of scientific results from the Genesis mission critically depends on the accuracy of analytical techniques. In this work, we report on simultaneous RIMS measurements of Ca and Cr performed on two silicon SW collector samples, (#60179 and #60476). First, we have conducted test experiments with 3×1013 at/cm2 52Cr and 44Ca implants in silicon to evaluate the accuracy of our quantitative analyses. Implant fluencies were measured by RIMS to be 2.73×1013 and 2.71×1013 at/cm2 for 52Cr and 44Ca, respectively, which corresponds to an accuracy of ≈10%. Using the same implanted wafer as a reference, we conducted RIMS analyses of the Genesis samples: 3 spots on #60179 and 4 spots on #60476. The elemental SW fluencies expected for Cr and Ca are 2.95×1010 and 1.33×1011 at/cm2 , respectively. Our measurements of 52Cr yielded 3.0±0.6×1011 at/cm2 and 5.1±4.1×1010 at/cm2 for #60179 and #60476, respectively. For 40Ca, SW fluencies of 1.39±0.70×1011 at/cm2 in #60179

Iron Hill (Powderhorn) carbonatite complex, Gunnison County, CO - A potential source of several uncommon mineral resources

USGS Publications Warehouse

Van Gosen, B. S.; Lowers, H.A.

2007-01-01

The Iron Hill (Powderhorn) carbonatite complex is a 31-kM2 (12-sq mile) alkalic intrusion located about 35 km (22 miles) south-southwest of Gunnison, CO. The intrusion has been well studied and described because of its classic petrology and architecture ofa carbonatite-alkalic complex. The complex is also noteworthy because it contains enrichments of titanium, rare earth elements, thorium, niobium (columbium), vanadium and deposits of vermiculite and nepheline syenite. In particular, the complex is thought to host the largest titanium and niobium resources in the United States, although neither has been developed. It may be economic to extract multiple resources from this complex with a well-coordinated mine and mill plan.

Doctor James Young Simpson, Rabbi Abraham De Sola, and Genesis Chapter 3, verse 16.

PubMed

Cohen, J

1996-11-01

When Dr. James Simpson began to use anesthesia in child-birth in 1846, a religious furor arose against its use. For many people, including many physicians, Genesis chapter 3, verse 16, implied that childbirth had to be a painful process. In 1849, the editors of one of Canada's medical journals asked Abraham De Sola, Canada's first rabbi, to give his interpretation of Genesis 3:16 for the benefit of their readers, which he did in a three-part article. Using Hebrew biblical scholars as his source, he wrote that the correct interpretation of this passage was that with toil or labor shall women bring forth children, rather than with pain. Therefore, by using anesthesia in childbirth, physicians were not going against the scriptures or the word of God.

CognitiveGenesis (CG): Assessing Academic Achievement and Cognitive Ability in Adventist Schools

ERIC Educational Resources Information Center

Thayer, Jerome; Kido, Elissa

2012-01-01

CognitiveGenesis collected achievement and ability test data from 2006-2009 for all students in Seventh-day Adventist schools in North America. Students were above average in achievement compared to national norms and achieved above that predicted by their ability scores. The more years students attended Adventist schools, the higher they…

Petrological and geochemical constraints on the recent increase in explosive activity at Santiaguito volcano, Guatemala

NASA Astrophysics Data System (ADS)

Wallace, Paul A.; Henton De Angelis, Sarah; De Angelis, Silvio; Kendrick, Jackie E.; Hornby, Adrian J.; Lamb, Oliver; von Aulock, Felix W.; Lamur, Anthony; Chigna, Gustavo; Rietbrock, Andreas; Dingwell, Donald B.; Lavallée, Yan

2017-04-01

The ability to forecast rapid changes in eruption style at highly active and dynamic volcanic systems is a fundamental aim for many geoscientists. Over the past century, Santiaguito's eruptive longevity of regular, small-to-moderate explosions (typical of dome-building episodes) have made it the ideal laboratory for the study of eruption dynamics. In 2015 this activity shifted to more violent, less regular explosive activity, potentially marking the onset of a renewed and recharged magmatic source. This study presents a unique, high resolution petrological and geochemical dataset using ash samples collected across this transition period, revealing detailed insights into the cause behind this rapid change in activity. Ash and bombs erupted between December 2015 and June 2016 are two-pyroxene andesites with whole-rock chemistry that is consistent with a long term trend towards more mafic material (Harris et al., 2003). Furthermore, although bulk chemistry is becoming more mafic, matrix glass compositions are the most evolved in all of Santiaguito's history. Despite this historical trend, the activity in early 2016 showed a rapid increase in bulk SiO2 (˜2 wt.%). The presence of xenocrystic olivine (Fo68-77) mantled by orthopyroxene (En69), a combination of normal and reverse zoned plagioclase phenocrysts (up to An91) and the majority of amphibole phenocrysts completely broken down to pseudomorphs provide strong evidence for a system in an advanced state of disequilibrium. Magma source conditions from amphibole suggest depths of ˜17-24.5 km and temperatures of ˜960-1010˚ C. Although depths are consistent with previous work (Scott et al., 2012), the data suggests elevated temperatures in the source region, a possible consequence of magmatic recharge. Through studying amphibole reaction rims, experiments suggest decompression alone would not be feasible to generate the textures recorded, thus providing evidence for a complex thermal and chemical history of the magma

Preliminary Quantification of Image Color Gradient on Genesis Concentrator Silicon Carbine Target 60001

NASA Technical Reports Server (NTRS)

Allton, J. H.; Calaway, M. J.; Rodriquez, M. C.

2008-01-01

The Genesis spacecraft concentrator was a device to focus solar wind ions onto a 6-cm diameter target area, thus concentrating the solar wind by 20X [1]. The target area was comprised of 4 quadrants held in place by a gold-coated stainless steel "cross" (Fig. 1). To date, two SiC and one chemical vapor deposited (CVD) quadrants have been imaged at 5X using a Leica DM-6000M in autoscan mode. Complete imaging of SiC sample 60001 required 1036 images. The mosaic of images is shown in Fig. 2 and position of analyzed areas in Fig. 3. This mosaic imaging is part of the curatorial documentation of surface condition and mapping of contamination. Higher magnification (50X) images of selected areas of the target and individual contaminant particles are compiled into reports which may be requested from the Genesis Curator [2].

Serpentinization and alteration in an olivine cumulate from the Stillwater Complex, Southwestern Montana

USGS Publications Warehouse

Page, N.J.

1976-01-01

Some of the olivine cumulates of the Ultramafic zone of the Stillwater Complex, Montana, are progressively altered to serpentine minerals and thompsonite. Lizardite and chrysotile developed in the cumulus olivine and postcumulus pyroxenes; thompsonite developed in postcumulus plagioclase. The detailed mineralogy, petrology, and chemistry indicate that olivine and plagioclase react to form the alteration products, except for H2O, without changes in the bulk composition of the rocks. ?? 1976 Springer-Verlag.

Phase equilibria modeling in igneous petrology: use of COMAGMAT model for simulating fractionation of ferro-basaltic magmas and the genesis of high-alumina basalt

NASA Astrophysics Data System (ADS)

Ariskin, Alexei A.

1999-05-01

A new version of COMAGMAT-3.5 model designed for computer simulations of equilibrium and fractional crystallization of basaltic magmas at low to high pressures is presented. The most important modifications of COMAGMAT include an ability to calculate more accurately the crystallization of magnetite and ilmenite, allowing the user to study numerically the effect of oxygen fugacity on basalt magma fractionation trends. Methodological principles of the use of COMAGMAT were discussed based on its thermodynamical and empirical basis, including specific details of the model calibration. Using COMAGMAT-3.5 a set of phase equilibria calculations (called Geochemical Thermometry) has been conducted for six cumulative rocks from the Marginal Border Series of the Skaergaard intrusion. As a result, initial magma temperature (1165±10°C) and trapped melt composition proposed to be parental magma to the Skaergaard intrusion were determined. Computer simulations of perfect fractionation of this composition as well as another proposed parent produced petrochemical trends opposite to those followed from natural observations. This is interpreted as evidence for an initial Skaergaard magma containing a large amount of olivine and plagioclase crystals (about 40-45%), so that the proposed and calculated parents are related through the melt trapped in the crystal-liquid mixture. This promotes the conclusion that the Skaergaard magma fractionation process was intermediate between equilibrium and fractional crystallization. In this case the classic Wager's trend should be considered an exception rather than a rule for the differentiation of ferro-basaltic magmas. A polybaric version of COMAGMAT has been applied for the genetic interpretation of a volcanic suite from the Klyuchevskoi volcano, Kamchatka, Russia. To identify petrological processes responsible for the observed suite ranging from high-magnesia to high-alumina basalts, we used the model to simulate the Klyuchevskoi suite

The Instrumental Genesis Process in Future Primary Teachers Using Dynamic Geometry Software

ERIC Educational Resources Information Center

Ruiz-López, Natalia

2018-01-01

This paper, which describes a study undertaken with pairs of future primary teachers using GeoGebra software to solve geometry problems, includes a brief literature review, the theoretical framework and methodology used. An analysis of the instrumental genesis process for a pair participating in the case study is also provided. This analysis…

Characterization of the Sukinda and Nausahi ultramafic complexes, Orissa, India by platinum-group element geochemistry

USGS Publications Warehouse

Page, N.J.; Banerji, P.K.; Haffty, J.

1985-01-01

Samples of 20 chromitite, 14 ultramafic and mafic rock, and 9 laterite and soil samples from the Precambrian Sukinda and Nausahi ultramafic complexes, Orissa, India were analyzed for platinum-group elements (PGE). The maximum concentrations are: palladium, 13 parts per billion (ppb); platinum, 120 ppb; rhodium, 21 ppb; iridium, 210 ppb; and ruthenium, 630 ppb. Comparison of chondrite-normalized ratios of PGE for the chromitite samples of lower Proterozoic to Archean age with similar data from Paleozoic and Mesozoic ophiolite complexes strongly implies that these complexes represent Precambrian analogs of ophiolite complexes. This finding is consistent with the geology and petrology of the Indian complexes and suggests that plate-tectonic and ocean basin developement models probably apply to some parts of Precambrian shield areas. ?? 1985.

Global petrologic variations on the moon: a ternary-diagram approach.

USGS Publications Warehouse

Davis, P.A.; Spudis, P.D.

1987-01-01

A ternary-diagram approach for determination of global petrologic variations on the lunar surface is presented that incorporates valuable improvements in our previous method of using geochemical variation diagrams. Our results are as follows: 1) the highlands contain large areas of relatively pure ferroan anorthosite; 2) the average composition of the upper lunar crust is represented by an 'anorthositic gabbro' composition; 3) KREEP/Mg-suite rocks are a minor fraction of the upper lunar crust; 4) within the farside highlands, areas of KREEP/Mg-suite rocks coincide mostly with areas of crustal thinning; 5) portions of the E limb and farside highlands have considerable amounts of a mafic, chondritic Th/Ti component (like mare basalt) whose occurrences coincide with mapped concentrations of light plains that display dark-halo craters.- from Authors

Cleaning Genesis Sample Return Canister for Flight: Lessons for Planetary Sample Return

NASA Technical Reports Server (NTRS)

Allton, J. H.; Hittle, J. D.; Mickelson, E. T.; Stansbery, Eileen K.

2016-01-01

Sample return missions require chemical contamination to be minimized and potential sources of contamination to be documented and preserved for future use. Genesis focused on and successfully accomplished the following: - Early involvement provided input to mission design: a) cleanable materials and cleanable design; b) mission operation parameters to minimize contamination during flight. - Established contamination control authority at a high level and developed knowledge and respect for contamination control across all institutions at the working level. - Provided state-of-the-art spacecraft assembly cleanroom facilities for science canister assembly and function testing. Both particulate and airborne molecular contamination was minimized. - Using ultrapure water, cleaned spacecraft components to a very high level. Stainless steel components were cleaned to carbon monolayer levels (10 (sup 15) carbon atoms per square centimeter). - Established long-term curation facility Lessons learned and areas for improvement, include: - Bare aluminum is not a cleanable surface and should not be used for components requiring extreme levels of cleanliness. The problem is formation of oxides during rigorous cleaning. - Representative coupons of relevant spacecraft components (cut from the same block at the same time with identical surface finish and cleaning history) should be acquired, documented and preserved. Genesis experience suggests that creation of these coupons would be facilitated by specification on the engineering component drawings. - Component handling history is critical for interpretation of analytical results on returned samples. This set of relevant documents is not the same as typical documentation for one-way missions and does include data from several institutions, which need to be unified. Dedicated resources need to be provided for acquiring and archiving appropriate documents in one location with easy access for decades. - Dedicated, knowledgeable

Modelling the genesis of equatorial podzols: age and implications for carbon fluxes

NASA Astrophysics Data System (ADS)

Doupoux, Cédric; Merdy, Patricia; Régina Montes, Célia; Nunan, Naoise; José Melfi, Adolpho; José Ribeiro Pereira, Osvaldo; Lucas, Yves

2017-05-01

Amazonian podzols store huge amounts of carbon and play a key role in transferring organic matter to the Amazon River. In order to better understand their C dynamics, we modelled the formation of representative Amazonian podzol profiles by constraining both total carbon and radiocarbon. We determined the relationships between total carbon and radiocarbon in organic C pools numerically by setting constant C and 14C inputs over time. The model was an effective tool for determining the order of magnitude of the carbon fluxes and the time of genesis of the main carbon-containing horizons, i.e. the topsoil and deep Bh. We performed retrocalculations to take into account the bomb carbon in the young topsoil horizons (calculated apparent 14C age from 62 to 109 years). We modelled four profiles representative of Amazonian podzols, two profiles with an old Bh (calculated apparent 14C age 6.8 × 103 and 8.4 × 103 years) and two profiles with a very old Bh (calculated apparent 14C age 23.2 × 103 and 25.1 × 103 years). The calculated fluxes from the topsoil to the perched water table indicate that the most waterlogged zones of the podzolized areas are the main source of dissolved organic matter found in the river network. It was necessary to consider two Bh carbon pools to accurately represent the carbon fluxes leaving the Bh as observed in previous studies. We found that the genesis time of the studied soils was necessarily longer than 15 × 103 and 130 × 103 years for the two younger and two older Bhs, respectively, and that the genesis time calculated considering the more likely settings runs to around 15 × 103-25 × 103 and 150 × 103-250 × 103 years, respectively.

Interdecadal Change of Tropical Cyclone Genesis Controlling Parameter in Western North Pacific

NASA Astrophysics Data System (ADS)

Li, T.

2017-12-01

The main environmental parameter controlling tropical cyclone (TC) genesis in the western North Pacific (WNP) changed in different interdecadal periods. The interannual variability of TC genesis frequency was primarily control by specific humidity in 1950-1976, sea surface temperature (SST) in 1977-1998, and vorticity in 1999-2014. A further diagnosis shows that the change of environmental specific humidity during 1950-1976 was attributed to anomalous advection of mean moisture during ENSO developing summer. The SST change during 1977-1998 was associated with circulation change during ENSO decaying summer. The change of environment vorticity was primarily related to CP-type El Niño during 1999-2014. The ultimate cause of the controlling parameter change is attributed to the change of ENSO behavior. Compared to the first period, a stronger EP-type ENSO variability in the second period leads to a stronger circulation/SST response during ENSO decaying phase. The occurrence of more frequent CP type El Niño in the third period was responsible for greater vorticity controlling in the WNP.

Enhanced Cleaning of Genesis Solar Wind Sample 61348 for Film Residue Removal

NASA Technical Reports Server (NTRS)

Allums, K. K.; Gonzalez, C. P.; Kuhlman, K. R.; Allton, J. H.

2015-01-01

The Genesis mission returned to Earth on September 8, 2004, experiencing a nonnominal reentry. During the recovery of the collector materials from the capsule, many of the collector fragments were placed on the adhesive protion of post-it notes to prevent the fragments from moving during transport back to Johnson Space Center. This unknowingly provided an additional contaminate that would prove difficult to remove with the limited chemistries allowed in the Genesis Curation Laboratory. Generally when collector material samples are prepared for allocation to PIs, the samples are cleaned front side only with Ultra-Pure Water (UPW) via megasonic dispersion to the collector surface to remove crash debris and contamination. While this cleaning method works well on samples that were not placed on post-its during recovery, it has caused movement of the residue on the back of the sample to be deposited on the front in at least two examples. Therefore, samples placed on the adhesive portion on post-it note, require enhanced cleaning methods since post-it residue has proved resistant to UPW cleaning.

Dynamics and Predictability of Tropical Cyclone Genesis, Structure and Intensity Change

DTIC Science & Technology

2012-09-30

analyses and forecasts of tropical cyclones, including genesis, intensity change, and extratropical transition. A secondary objective is to understand... storm -centered assimilation algorithm. Basic research in Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the...COMPLETED For the four storms consider (Nuri, Jangmi, Sinlaku, and Hagupit), an 80-member EnKF has been cycled on observations (surface, rawinsondes, GPS

Petrologic insights into basaltic volcanism at historically active Hawaiian volcanoes: Chapter 6 in Characteristics of Hawaiian volcanoes

USGS Publications Warehouse

Helz, Rosalind L.; Clague, David A.; Sisson, Thomas W.; Thornber, Carl R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

2014-01-01

Contributions to our knowledge of the nature of the mantle source(s) of Hawaiian basalts are reviewed briefly, although this is a topic where debate is ongoing. Finally, our accumulated petrologic observations impose constraints on the nature of the summit reservoirs at Kīlauea and Mauna Loa, specifically whether the summit chamber has been continuous or segmented during past decades.

GENESIS: new self-consistent models of exoplanetary spectra

NASA Astrophysics Data System (ADS)

Gandhi, Siddharth; Madhusudhan, Nikku

2017-12-01

We are entering the era of high-precision and high-resolution spectroscopy of exoplanets. Such observations herald the need for robust self-consistent spectral models of exoplanetary atmospheres to investigate intricate atmospheric processes and to make observable predictions. Spectral models of plane-parallel exoplanetary atmospheres exist, mostly adapted from other astrophysical applications, with different levels of sophistication and accuracy. There is a growing need for a new generation of models custom-built for exoplanets and incorporating state-of-the-art numerical methods and opacities. The present work is a step in this direction. Here we introduce GENESIS, a plane-parallel, self-consistent, line-by-line exoplanetary atmospheric modelling code that includes (a) formal solution of radiative transfer using the Feautrier method, (b) radiative-convective equilibrium with temperature correction based on the Rybicki linearization scheme, (c) latest absorption cross-sections, and (d) internal flux and external irradiation, under the assumptions of hydrostatic equilibrium, local thermodynamic equilibrium and thermochemical equilibrium. We demonstrate the code here with cloud-free models of giant exoplanetary atmospheres over a range of equilibrium temperatures, metallicities, C/O ratios and spanning non-irradiated and irradiated planets, with and without thermal inversions. We provide the community with theoretical emergent spectra and pressure-temperature profiles over this range, along with those for several known hot Jupiters. The code can generate self-consistent spectra at high resolution and has the potential to be integrated into general circulation and non-equilibrium chemistry models as it is optimized for efficiency and convergence. GENESIS paves the way for high-fidelity remote sensing of exoplanetary atmospheres at high resolution with current and upcoming observations.

Combined magnetotelluric and petrologic constrains for the nature of the magma storage system beneath the Ciomadul volcano (SE Carpathians)

NASA Astrophysics Data System (ADS)

Novák, A.; Harangi, Sz.; Kiss, B.; Szarka, L.; Molnár, Cs.

2012-04-01

The Ciomadul volcano is the youngest in the Carpathian-Pannonian region (eastern-central Europe) and there are indications that magma could still reside at the depth. Therefore, we performed a magnetotelluric investigation with the aim to detect a still hot magma reservoir. The results were compared with those coming from the petrological investigations. The Ciomadul volcanic complex contains a central amalgamated set of lava domes and a few peripheral domes with two explosion craters in the central zone. Geologically the domes were built by effusion of high viscosity dacite magma. Lava dome collapses resulted in volcanoclastic deposits (block-and ash flow deposits). The magmatic activity could have been connected to the seismically powerful region of the nearby Vrancea zone. Twelve long period magnetotelluric (MT) soundings were carried out to aim of define to electric resistivity distribution of the volcanic system and find correlation with the petrologic model to confirm the hot magma chamber beneath the region. At each MT site, the horizontal components of the magnetic and the electric fields were observed between the 0.00006-4 Hz frequency range. The vertical component of the magnetic field was also recorded to analyze the lateral conductivity inhomogenities under the subsurface. Soundings were located in non systematic grid and we selected several profiles which may represent the resistivity distribution of subsurface and cross-sections were applied as well. At started by dimensionality analysis and decomposition parameters the most part of the measuring are multi-dimensional. Traditional MT interpretation - 1D, 2D inversion and modeling - was carried out taking into account the decomposition results. 3D interpretation is not realized because of weak resolution of the data and large memory requirement. Both the local 1D inversion and the 2D inversion along the profiles defined a low resistivity zones at about 2 km depth which in continuation at depth with a

Petrology of the 1877 eruption of Cotopaxi Volcano, Ecuador: Insight on magma evolution and storage

NASA Astrophysics Data System (ADS)

Saalfeld, M. A.; Panter, K. S.; Kelley, D.

2017-12-01

Cotopaxi is a stratovolcano in the Northern Andes Volcanic Zone, and has a history of bimodal volcanism, alternating between rhyolite and andesite. With Cotopaxi reawakening in 2015 after 100 years of quiescence, the question of what is occurring beneath the surface becomes especially poignant. To answer this question, we must look to the volcano's past. This work characterizes the mineralogy and geochemistry of the recent eruptive products of Cotopaxi, with emphasis on the two pulses of the 1877 eruption. Additionally, pressure and temperature are estimated for magmas prior to eruption. This will allow a better understanding of the magma plumbing system and its evolution over time. Over the past 500 years Cotopaxi has had five major eruptive events (VEI 3-4), which occurred in 1532, 1742, 1744, 1768, and 1877, and included pyroclastic surges, scoria flows, and lahars. After the initial pulse of the 1877 eruption and the subsequent lahars, a second pulse of magma produced a pyroclastic density current containing scoria clasts up to 1 meter in diameter. All samples are basaltic andesite to andesite (56-59 wt. % SiO2), and a mineral assemblage of pl + opx + cpx + mag ± ol. Plagioclase range from An47 to An78 and show both normal and reverse zoning. Normally zoned crystals exhibit greater compositional variation between cores and rims than reversely zoned crystals (median Ancore-Anrim 8% vs 4%, respectively), indicating that crystal fractionation is a dominant process but that mixing also played a role in magma genesis. Pyroxenes occur as augite and enstatite and do not exhibit significant zoning. The similar petrology of these eruptions suggests that they were part of a relatively long-lived system that underwent differentiation and replenishment between eruptions. Thermobarometric data indicate that magma storage occurred at temperatures of 1100-1150°C and pressures ranging from 2 kbar (during the 1877 eruption) to 4 kbar (during the 1742 eruption), which is

Studies of Brazilian meteorites. XIV - Mineralogy, petrology, and chemistry of the Conquista, Minas Gerais, chondrite

NASA Technical Reports Server (NTRS)

Keil, K.; Kirchner, E.; Gomes, C. B.; Jarosewich, E.; Murta, R. L. L.

1978-01-01

The Conquista chondrite is described and classified as an H4. The mineral composition is reported. H-group classification is based on described microscopic, electron microprobe, and bulk chemical studies. The evidence for petrologic type 4 classification includes the pronounced well-developed chondritic texture; the slight compositional variations in constituent phases; the high Ca contents of pyroxene and the presence of pigeonite; glassy to microcrystalline interstitial material rich in alkalis and SiO2; and twinned low-Ca clinopyroxene.

Petrology and Geochemistry of New Paired Martian Meteorites Larkman Nunatak 12240 and Larkman Nunatak 12095

NASA Technical Reports Server (NTRS)

Funk, R. C.; Peslier, A. H.; Brandon, A. D.; Humayun, M.

2016-01-01

Two of the latest Martian meteorites found in Antarctica, paired olivine-phyric shergottites LAR 12240 and LAR 12095, are described in order to decipher their petrological context, and place constraints on the geological history of Mars. This project identifies all phases found in LAR 12240 and 12095 and analyzes them for major and trace elements. The textural relationships among these phases are examined in order to develop a crystallization history of the magma(s) that formed these basalts.

Interdecadal variation of tropical cyclone genesis and its relationship to the convective activities over the central Pacific

NASA Astrophysics Data System (ADS)

Huangfu, Jingliang; Huang, Ronghui; Chen, Wen

2018-02-01

Using the outgoing longwave radiation (OLR) data from the National Oceanic and Atmospheric Administration archives, this paper analyzes the interdecadal variation of convective activities over the central Pacific (CP) from July to October of 1979-2013 and its impact on tropical cyclone (TC) genesis in the western North Pacific (WNP). Concurrent with the interdecadal decrease of TC genesis, the tropical convection underwent a significant interdecadal change in the late 1990s. Overall, the first leading empirical orthogonal function mode of the tropical OLR during July-October turned from a zonal dipole pattern during 1979-1997 to a tripole pattern during 1998-2013. Concomitant to this change, the boreal part of the Walker circulation shrank westward, with its downdraft branch located over the CP. The downward motion anomalies over the CP increased after the late 1990s, as did the trade easterlies. Consistent with the CP convective activity anomalies, the negative low-level relative vorticity anomalies and upper-level divergence anomalies, positive vertical wind shear anomalies and anomalous abundant water vapor can be observed over the southeastern part of the WNP. Additionally, the tropical depression (TD)-type waves associated with the CP convective activities are significantly different before and after the late 1990s. Before the late 1990s, the off-equatorial TD-type waves could be distinctly observed, with clear transitions located along the WNP monsoon trough. However, these transitions were vague after the late 1990s. Therefore, the convective activities over the CP may have played an important role in affecting the interdecadal change of TC genesis by affecting the genesis of TD-type waves.

Geology, petrology and geochronology of the Lago Grande layered complex: Evidence for a PGE-mineralized magmatic suite in the Carajás Mineral Province, Brazil

NASA Astrophysics Data System (ADS)

Teixeira, Antonio Sales; Ferreira Filho, Cesar Fonseca; Giustina, Maria Emilia Schutesky Della; Araújo, Sylvia Maria; da Silva, Heloisa Helena Azevedo Barbosa

2015-12-01

ultramafic lithotypes render Nd model ages between 2.94 and 3.56 Ga, with variably negative ɛNd (T = 2.72 Ga) values (-0.32 to -4.25). The crystallization sequence of the intrusion and the composition of cumulus minerals, together with lithogeochemical and Nd isotopic results, are consistent with an original mantle melt contaminated with older continental crust. The contamination of mafic magma with sialic crust is also consistent with intra-plate rifting models proposed in several studies of the CMP. Lithogeochemical and isotopic data from the Lago Grande Complex may also be interpreted as the result of melting an old lithospheric mantle, and alternative models should not be disregarded. PGE mineralizations occur in chromitites and associated with base metal sulfides in the Lago Grande Complex. Chromitite has the highest PGE content (up to 10 ppm) and is characterized by high Pt/Pd ratio (4.3). Mantle-normalized profile of chromitite is highly enriched in PPGE and similar to those from Middle Group (MG) and Upper Group (UG) chromitites from the Bushveld Complex. Platinum group minerals (PGM) occur mainly at the edge of chromite crystals in the Lago Grande chromitite, consisting of arsenides and sulfo-arsenides. Sulfide-bearing harzburgite samples of the Lago Grande complex have PGE content of up to 1 ppm and low Pt/Pd (0.2-0.3) ratios. The 2722 ± 53 Ma U-Pb zircon age determined in this study for the Lago Grande Complex overlaps with the crystallization age of the Luanga Complex. Previous interpretation that the Lago Grande and Luanga layered intrusions are part of a magmatic suite (i.e., Serra Leste Magmatic Suite) is now reinforced by similar fractionation sequences, comparable petrological evolution and overlapped U-Pb zircon ages. The occurrence of the same styles of PGE mineralization in the Lago Grande and Luanga complexes, together with remarkably similar chondrite-normalized PGE profiles and PGE minerals for chromitites of both complexes, support the concept that

Garnet Signatures in Geophysical and Geochemical Observations: Insights into the Thermo-Petrological Structure of Oceanic Upper Mantle

NASA Astrophysics Data System (ADS)

Grose, C. J.; Afonso, J. C.

2013-12-01

We have developed new physically comprehensive thermal plate models of the oceanic lithosphere which incorporate temperature- and pressure-dependent heat transport properties and thermal expansivity, melting beneath ridges, hydrothermal circulation near ridge axes, and insulating oceanic crust. These models provide good fits to global databases of seafloor topography and heat flow, and seismic evidence of thermal structure near ridge axes. We couple these thermal plate models with thermodynamic models to predict the petrology of oceanic lithosphere. Geoid height predictions from our models suggest that there is a strong anomaly in geoid slope (over age) above ~25 Ma lithosphere due to the topography of garnet-field mantle. A similar anomaly is also present in geoid data over fracture zones. In addition, we show that a new assessment of a large database of ocean island basalt Sm/Yb systematics indicates that there is an unmistakable step-like increase in Sm/Yb values around 15-20 Ma, indicating the presence of garnet. To explain this feature, we have attempted to couple our thermo-petrological models of oceanic upper mantle with an open system, non-modal, dynamic melting model with diffusion kinetics to investigate trace element partitioning in an ascending mantle column.

The Genesis Project: Science Cases for a Large Submm Telescope

NASA Astrophysics Data System (ADS)

Schneider, Nicola

2018-01-01

The formation of stars is intimately linked to the structure and evolution of molecular clouds in the interstellar medium. In the context of the ANR/DFG project GENESIS (GENeration and Evolution of Structures in the Ism, http://www.astro.uni-koeln.de/node/965), we explore this link with a new approach by combining far-infrared maps and surveys of dust (Herschel) and cooling lines (CII, CI, CO, OI with SOFIA), with molecular line maps. Dedicated analysis tools are used to characterise molecular cloud structure, and we explore the coupling of turbulence with heating- and cooling processes. The project gathers a large observational data set, from molecular line maps at (sub)-mm wavelengths from ground-based telescopes (e.g. IRAM) up to high-frequency airborne spectroscopic and continuum observations (SOFIA). Nevertheless, we identified the need for a large single-dish submm telescope, operating in the southern hemisphere at high frequencies. Only such an instrument is able to observe important ISM cooling lines, like the CI lines at 490 and 810 GHz or high-J CO lines, shock tracers, or probes of turbulence dissipation with high angular resolution in Galactic and extragalactic sources. We will discuss possible science cases and demonstrate how those are addressed within GENESIS, and the science done with the new 6m Cologne-Cornell CCAT-prime submm telescope.

Petrological and seismic precursors of the paroxysmal phase of the last Vesuvius eruption on March 1944

PubMed Central

Pappalardo, Lucia; D'Auria, Luca; Cavallo, Andrea; Fiore, Stefano

2014-01-01

Abrupt transitions in style and intensity are common during volcanic eruptions, with an immediate impact on the surrounding territory and its population. Defining the factors trigger such sudden shifts in the eruptive behavior as well as developing methods to predict such changes during volcanic crises are crucial goals in volcanology. In our research, the combined investigation of both petrological and seismic indicators has been applied for the first time to a Vesuvius eruption, that of March 1944 that caused the present dormant state of the volcano. Our results contribute to elucidate the evolution of the conduit dynamics that generated a drastic increase in the Volcanic Explosivity Index, associated to the ejection of huge amount of volcanic ash. Remarkably, our study shows that the main paroxysm was announced by robust changes in petrology consistent with seismology, thus suggesting that the development of monitoring methods to assess the nature of ejected juvenile material combined with conventional geophysical techniques can represent a powerful tool for forecasting the evolution of an eruption towards violent behavior. This in turn is a major goal in volcanology because this evidence can help decision-makers to implement an efficient safety strategy during the emergency (scale and pace of evacuation). PMID:25199537

Petrology and Geochemistry of Unbrecciated Harzburgitic Diogenite MIL 07001: A Window Into Vestan Geological Evolution

NASA Technical Reports Server (NTRS)

Mittlefehldt, D. W.; Peng, Z. X.; Mertzman, S. A.; Mertzman, K. R.

2014-01-01

There is a strong case that asteroid 4 Vesta is the parent of the howardite, eucrite and diogenite (HED) meteorites. Models developed for the geological evolution of Vesta can satisfy the compositions of basaltic eucrites that dominate in the upper crust. The bulk compositional characteristics of diogenites - cumulate harzburgites and orthopyroxenites from the lower crust - do not fit into global magma ocean models that can describe the compositions of basaltic and cumulate eucrites. Recent more detailed formation models do make provision for a more complicated origin for diogenites, but this model has yet to be completely vetted. Compositional studies of bulk samples has led to the hypothesis that many diogenites were formed late by interaction of their parent melts with a eucritic crust, but those observations may alternatively be explained by subsolidus equilibration of trace elements between orthopyroxene and plagioclase and Ca-phosphate in the rocks. Differences in radiogenic Mg-26 content between diogenites and eucrites favors early formation of the former, not later formation. Understanding the origin of diogenites is crucial for understanding the petrologic evolution of Vesta. We have been doing coordinated studies of a suite of diogenites including petrologic investigations, bulk rock major and trace element studies, and in situ trace element analyses of orthopyroxene. Here we will focus on an especially unusual, and potentially key, diogenite, MIL 07001.

Size Distribution of Genesis Solar Wind Array Collector Fragments Recovered

NASA Technical Reports Server (NTRS)

Allton, J. H.; Stansbery, E. K.; McNamara, K. M.

2005-01-01

Genesis launched in 2001 with 271 whole and 30 half hexagonally-shaped collectors mounted on 5 arrays, comprised of 9 materials described in [1]. The array collectors were damaged during re-entry impact in Utah in 2004 [2], breaking into many smaller pieces and dust. A compilation of the number and approximate size of the fragments recovered was compiled from notes made during the field packaging performed in the Class 10,000 cleanroom at Utah Test and Training Range [3].

Geophysical, petrological and mineral physics constraints on Earth's surface topography

NASA Astrophysics Data System (ADS)

Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

2015-04-01

modeled topography. We also test several viscosity models, either radially symmetric, the V1 profile from Mitrovica and Forte [2004], or more complex laterally varying structures. All the property fields are expanded in spherical harmonics, until degree 24, and implemented in the code StagYY [Tackley, 2008] to perform mantle instantaneous flow modeling and compute surface topography and gravitational field. Our results show the importance of constraining the crustal and mantle density structure relying on a multidisciplinary approach that involves experimentally robust thermodynamic datasets. Crustal density field has a strong effect on the isostatic component of topography. The models that we test, CRUST 1.0 and those in Guerri and Cammarano [2015], produce strong differences in the computed isostatic topography, in the range ±600 m. For the lithospheric mantle, relying on experimentally robust material properties constraints is necessary to infer a reliable density model that takes into account chemical heterogeneities. This approach is also fundamental to correctly interpret seismic models in temperature, a crucial parameter, necessary to determine the lithosphere-asthenosphere boundary, where static effects on topography leave place to dynamic ones. The comparison between results obtained with different viscosity fields, either radially symmetric or vertically and laterally varying, shows how lateral viscosity variations affect the results, in particular the modeled geoid, at different wavelengths. References: Brocher, T. M. (2005), Empirical Relations between Elastic Wavespeeds and Density in the Earth's Crust, Bulletin of the Seismological Society of America, 95(6), 2081-2092. Cammarano, F., P. J. Tackley, and L. Boschi (2011), Seismic, petrological and geodynamical constraints on thermal and compositional structure of the upper mantle: global thermochemical models, Geophys. J. Int. Connolly, J. A. D. (2005), Computation of phase equilibria by linear programming: A

APPLICATIONS OF CATHODOLUMINESCENCE OF QUARTZ AND FELDSPAR TO SEDIMENTARY PETROLOGY.

USGS Publications Warehouse

Ruppert, Leslie F.

1987-01-01

Cathodoluminescence (CL), the emission of visible light during electron bombardment, was first used in sandstone petrology in the mid-1960's. CL techniques are especially useful for determining the origin and source of quartz and feldspar, two of the most common constituents in clastic rocks. CL properties of both minerals are dependent on their temperature of crystallization, duration of cooling, and/or history of deformation. Detrital quartz and feldspar are typically derived from igneous and metamorphic sources and luminesce in the visible range whereas authigenic quartz and feldspar form at low temperatures and do not luminesce. Quantification of luminescent and non-luminescent quartz and feldspar with the scanning electron microscope, electron microprobe, or a commercial CL device can allow for the determination of origin, diagenesis, and source of clastic rocks when used in conjunction with field and other petrographic analyses.

Apollo 15 yellow impact glasses: Chemistry, petrology, and exotic origin

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

Delano, J.W.; Lindsley, D.H.; Ma, M.

1982-11-15

The Apollo 15 yellow impact glasses are characterized by moderate TiO/sub 2/ (approx.4.8%) and high abundances of the large ion lithophile elements (e.g., K, P, Hf, Th, REE). Since the chemistry of these glasses cannot be duplicated by any combination of local components presently known to occur at the Apollo 15 landing site, these yellow glasses seem to be exotic to that area. Chemical and petrologic constraints suggest that these samples were produced by impact melting of an immature mare regolith developed upon an unusual variety of mare basalt. We speculate that the target basalt were the youngest lava flowsmore » known to exist on the moon (i.e., Eratosphenian-age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.« less

Mineralogy and Petrology of Amoeboid Olivine Inclusions in CO3 Chondrites: Relationship to Parent-Body Aqueous Alteration

NASA Technical Reports Server (NTRS)

Chizmadia, Lysa J.; Rubin, Alan E.; Wasson, John T.

2003-01-01

Petrographic and mineralogic studies of amoeboid olivine inclusions (AOIs) in CO3 carbonaceous chondrites reveal that they are sensitive indicators of parent-body aqueous and thermal alteration. As the petrologic subtype increases from 3.0 to 3.8, forsteritic olivine (Fa(sub 0-1)) is systematically converted into ferroan olivine (Fa(sub 60-75)). We infer that the Fe, Si and O entered the assemblage along grain boundaries, forming ferroan olivine that filled fractures and voids. As temperatures increased, Fe(+2) from the new olivine exchanged with Mg(+2) from the original AOI to form diffusive haloes around low-FeO cores. Cations of Mn(+2), Ca(+2) and Cr(+3) were also mobilized. The systematic changes in AOI textures and olivine compositional distributions can be used to refine the classification of CO3 chondrites into subtypes. In subtype 3.0, olivine occurs as small forsterite grains (Fa(sub 0-1)), free of ferroan olivine. In petrologic subtype 3.2, narrow veins of FeO-rich olivine have formed at forsterite grain boundaries. With increasing alteration, these veins thicken to form zones of ferroan olivine at the outside AOI margin and within the AOI interior. By subtype 3.7, there is a fairly broad olivine compositional distribution in the range Fa(sub 63-70), and by subtype 3.8, no forsterite remains and the high-Fa peak has narrowed, Fa(sub 64-67). Even at this stage, there is incomplete equilibration in the chondrite as a whole (e.g., data for coarse olivine grains in Isna (CO3.8) chondrules and lithic clasts show a peak at Fa(sub39)). We infer that the mineral changes in A01 identified in the low petrologic types required aqueous or hydrothermal fluids whereas those in subtypes greater than or equal to 3.3 largely reflect diffusive exchange within and between mineral grains without the aid of fluids.

Report of the Workshop on Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of Martian Meteorites

NASA Technical Reports Server (NTRS)

Treiman, Allan H. (Editor); Herd, Christopher D. K. (Editor)

2002-01-01

Geochemical and petrologic studies of the Martian meteorites (nicknamed the SNCs) have proliferated in the past few years, from a wealth of new samples and the perfection of new analytical methods. An intriguing result from these studies is that the chemical and isotopic compositions of the Martian meteorites, all basalts or derived from basaltic magma, can be modeled as mixtures of a limited number of components. These mixing components were the focus of the workshop.

NASA's Genesis and Rapid Intensification Processes (GRIP) Field Experiment

NASA Technical Reports Server (NTRS)

Braun, Scott A.; Kakar, Ramesh; Zipser, Edward; Heymsfield, Gerald; Albers, Cerese; Brown, Shannon; Durden, Stephen; Guimond, Stephen; Halverson, Jeffery; Heymsfield, Andrew;

Genesis of the Mechanical Heart Valves' Ultrasonic Closing Clicks

NASA Astrophysics Data System (ADS)

Hasegawa, Jun; Kobayashi, Kenji

A new in vitro experimental tool was developed to study the mechanism of the ultrasonic closing clicks' genesis of mechanical heart valves. Since the newly developed tester adopted compressed air flow directly instead of the blood analog fluid to drive the mechanical heart valve, it is not possibe to generate any cavitation. Closing clicks were measured with a small accelerometer at the surface of the valve holder made of silicone rubber. Ultrasonic closing clicks as well as audible closing clicks, similar to those measured clinically, could be observed using this setup. Thus, it was confirmed that the ultrasonic closing clicks can be generated without the existence of cavitation. Simultaneous measurements of the valve motion were made with a high-speed video camera, and the analysis of the video frames and clicks showed that higher frequency signal components of more than 50kHz could be generated only at the instant of the closure, which means the collision of the occluder with the housing. Eighteen miniature accelerometers with an area of one square millimeter were developed and stuck on the housing to monitor the distribution of the housing vibrations in detail, and it was found that the vibrations correspond to the ultrasonic closing clicks propagated from the valve stop: the collision point of the occluder with the housing. This fact indicated that the generation of ultrasonic closing clicks are limited to the small area of the collision. From those results, it was concluded that the major origin of the ultrasonic closing clicks' genesis should be the collision of the occluder with the housing.

The 2006-2009 activity of the Ubinas volcano (Peru): Petrology of the 2006 eruptive products and insights into genesis of andesite magmas, magma recharge and plumbing system

NASA Astrophysics Data System (ADS)

Rivera, Marco; Thouret, Jean-Claude; Samaniego, Pablo; Le Pennec, Jean-Luc

2014-01-01

Following a fumarolic episode that started six months earlier, the most recent eruptive activity of the Ubinas volcano (south Peru) began on 27 March 2006, intensified between April and October 2006 and slowly declined until December 2009. The chronology of the explosive episode and the extent and composition of the erupted material are documented with an emphasis on ballistic ejecta. A petrological study of the juvenile products allows us to infer the magmatic processes related to the 2006-2009 eruptions of the andesitic Ubinas volcano. The juvenile magma erupted during the 2006 activity shows a homogeneous bulk-rock andesitic composition (56.7-57.6 wt.% SiO2), which belongs to a medium- to high-K calc-alkaline series. The mineral assemblage of the ballistic blocks and tephra consists of plagioclase > two-pyroxenes > Fe-Ti oxide and rare olivine and amphibole set in a groundmass of the same minerals with a dacitic composition (66-67 wt.% SiO2). Thermo-barometric data, based on two-pyroxene and amphibole stability, records a magma temperature of 998 ± 14 °C and a pressure of 476 ± 36 MPa. Widespread mineralogical and textural features point to a disequilibrium process in the erupted andesite magma. These features include inversely zoned "sieve textures" in plagioclase, inversely zoned clinopyroxene, and olivine crystals with reaction and thin overgrowth rims. They indicate that the pre-eruptive magmatic processes were dominated by recharge of a hotter mafic magma into a shallow reservoir, where magma mingling occurred and triggered the eruption. Prior to 2006, a probable recharge of a mafic magma produced strong convection and partial homogenization in the reservoir, as well as a pressure increase and higher magma ascent rate after four years of fumarolic activity. Mafic magmas do not prevail in the Ubinas pre-historical lavas and tephras. However, mafic andesites have been erupted during historical times (e.g. AD 1667 and 2006-2009 vulcanian eruptions). Hence

Magmatic plumbing system of Kilauea Volcano: Insights from Petrologic and Geochemical Monitoring

NASA Astrophysics Data System (ADS)

Garcia, M. O.; Pietruszka, A. J.; Marske, J.; Greene, A.; Lynn, K. J.

2016-12-01

Monitoring the petrology and geochemistry of lavas from active volcanoes in near realtime affords the opportunity to formulate and evaluate models for magma transport, mixing, and storage to help predict eruption scenarios with greater confidence and better understand magmatic plumbing systems (e.g., Poland et al. 2012, Nat. Geosci. 5, 295-300). Continous petrologic and geochemical monitoring of two ongoing eruptions at the summit and east rift zone of Kilauea Volcano on the Island of Hawaii have revealed much about the dynamics of magmatic processes. When the composition of lava shifted to a more MgO-rich composition in April 1983, we predicted that the Puu Oo eruption would not be short-lived. We had no idea it would continue for over 33 years. Subsequent changes in lava composition have highlighted the interplay between mixing pockets of rift-zone stored magma with new mantle-derived magma and the cooling-induced crystal fractionation during brief (usually days) eruption hiatuses. Surprisingly, the mantle derived magma has continued to change in composition including several 10-year cycles in Pb isotope ratios superimposed on a progressive depletion in highly incompatible elements (Greene et al. 2013, G3, doi: 10.1002/ggge.20285). These compositional trends are contrary to those observed for sustained basaltic eruptions on continents and argue for melt extraction from a multi-component source with 1-3 km wide heterogeneities. Compositional zoning within olivine phenocrysts, created by diffusive re-equilibration, also provide insights into magma mixing, storage, and transport at Kilauea. Timescales modeling of Fe-Mg and Ni concentration gradients within Puu Oo olivine indicate that crystals can be stored at magmatic temperatures for months to a few years before eruption (Shea et al. 2015, Geology 43, 935-938). Kilauea's ongoing eruptions continue to provide a dynamic laboratory for positing and testing models for the generation and evolution of basaltic magma.

Detection of tectonometamorphic discontinuities within the Himalayan orogen: Structural and petrological constraints from the Rasuwa district, central Nepal Himalaya

NASA Astrophysics Data System (ADS)

Rapa, Giulia; Mosca, Pietro; Groppo, Chiara; Rolfo, Franco

2018-06-01

A detailed structural, lithological and petrological study of different transects in the Rasuwa district of central Nepal Himalaya allows the characterization of the tectonostratigraphic architecture of the area. It also facilitates constraining the P-T evolution of the different units within the Lesser (LHS) and Greater (GHS) Himalayan Sequences. Peak P-T conditions obtained for the studied metapelite samples using the pseudosection approach and the Average PT method highlight the existence of four different T/P ratio populations in different tectonometamorphic units: 80 ± 11 °C/kbar (LHS), 66 ± 7 °C/kbar (RTS), 73 ± 1 °C/kbar (Lower-GHS) and 101 ± 12 °C/kbar (Upper-GHS). Integration of structural and petrological data emphasizes the existence of three tectonometamorphic discontinuities bounding these units, characterized by top-to-the-south sense of shear: the Ramgarh Thrust, which separates the LHS (peak metamorphism at ∼600 °C, 7.5 kbar) from the overlying RTS (peak metamorphism at ∼635 °C, 10 kbar); the Main Central Thrust, which separates the RTS from the Lower-GHS (peak at 700-740 °C, 9.5-10.5 kbar with a prograde increase in both P and T in the kyanite stability field), and the Langtang Thrust, which juxtaposes the Upper-GHS (peak at 780-800 °C, 7.5-8.0 kbar with a nearly isobaric heating in the sillimanite stability field) onto the Lower-GHS. An increase in the intensity of deformation, with development of pervasive mylonitic fabrics and/or shear zones, is generally observed approaching the discontinuities from either side. Overall, data and results presented in this paper demonstrate that petrological and structural analysis combined together, are reliable methods adequate to identify tectonometamorphic discontinuities in both the LHS and GHS. Geochronological data from the literature allow the interpretation of these discontinuities as in-sequence thrusts.

Petrological insights into intermediate-depths of a subduction plate interface

NASA Astrophysics Data System (ADS)

Angiboust, Samuel; Agard, Philippe

2013-04-01

Understanding processes acting along the subduction interface is crucial to assess lithospheric scale coupling between tectonic plates, exhumation of deep-seated rocks and mechanisms causing intermediate-depth seismicity. Yet, despite a wealth of geophysical studies aimed at better characterizing the subduction interface, we still lack critical petrological data constraining such processes as intermediate-seismicity within oceanic subduction zones. This contribution reviews recent findings from two major localities showing deeply subducted ophiolitic remnants (Zermatt-Saas, Monviso), which crop out in the classic, well-preserved fossil subduction setting of the Western Alps. We herein show that both ophiolite remnants represent large, relatively continuous fragments of oceanic lithosphere (i.e., several km-thick tectonic slices across tens of km) exhumed from ~80 km depths and thereby provide important constraints on interplate coupling mechanisms. In both fragments (but even more so in the Zermatt-Saas one) pervasive hydrothermal processes and seafloor alteration, promoting fluid incorporation in both mafic and associated ultramafic rocks, was essential, together with the presence of km-thick serpentinite soles, to decrease the density of the tectonic slices and prevent them from an irreversible sinking into the mantle. The Monviso case sudy provides further insights into the subduction plate interface at ~80 km depths. The Lago Superiore Unit, in particular, is made of a 50-500 m thick eclogitized mafic crust (associated with minor calcschist lenses) overlying a 100-400 m thick metagabbroic body and a km-thick serpentinite sole, and is cut by two 10 to 100m thick eclogite-facies shear zones, respectively located at the boundary between basalts and gabbros, and between gabbros and serpentinites (the Lower Shear Zone: LSZ). The LSZ gives precious information on both seismicity and fluid flow: (1) Eclogite breccias, reported here for the first time, mark the locus

[Networks and genesis of living beings: epistemologic perspectives].

PubMed

Perru, Olivier

2007-01-01

Our paper focuses on Stuart Kauffman's theory from 1993 to 2004. Kauffman is looking for an explanation of the genesis of living beings by genetic networks. From interactions to cell types, Kauffman's viewpoint is concerned with differentiation and self-organization as network's properties. His approach of morphogenetic processes is interesting but it is insufficient. According to Sole, Fernandez and Kauffman [2003], networks would give an explanation of the diversity in patterns and cell types. Some other authors [as Perkins et al., 2004] consider that it is necessary to explore interactions, not with logical methods only, but non-linear systems too. Network's structure is related to biological diversity. It supposes genes' power's mediators within the cells and between them.

A climatological model of North Indian Ocean tropical cyclone genesis, tracks and landfall

NASA Astrophysics Data System (ADS)

Wahiduzzaman, Mohammad; Oliver, Eric C. J.; Wotherspoon, Simon J.; Holbrook, Neil J.

2017-10-01

Extensive damage and loss of life can be caused by tropical cyclones (TCs) that make landfall. Modelling of TC landfall probability is beneficial to insurance/re-insurance companies, decision makers, government policy and planning, and residents in coastal areas. In this study, we develop a climatological model of tropical cyclone genesis, tracks and landfall for North Indian Ocean (NIO) rim countries based on kernel density estimation, a generalised additive model (GAM) including an Euler integration step, and landfall detection using a country mask approach. Using a 35-year record (1979-2013) of tropical cyclone track observations from the Joint Typhoon Warning Centre (part of the International Best Track Archive Climate Stewardship Version 6), the GAM is fitted to the observed cyclone track velocities as a smooth function of location in each season. The distribution of cyclone genesis points is approximated by kernel density estimation. The model simulated TCs are randomly selected from the fitted kernel (TC genesis), and the cyclone paths (TC tracks), represented by the GAM together with the application of stochastic innovations at each step, are simulated to generate a suite of NIO rim landfall statistics. Three hindcast validation methods are applied to evaluate the integrity of the model. First, leave-one-out cross validation is applied whereby the country of landfall is determined by the majority vote (considering the location by only highest percentage of landfall) from the simulated tracks. Second, the probability distribution of simulated landfall is evaluated against the observed landfall. Third, the distances between the point of observed landfall and simulated landfall are compared and quantified. Overall, the model shows very good cross-validated hindcast skill of modelled landfalling cyclones against observations in each of the NIO tropical cyclone seasons and for most NIO rim countries, with only a relatively small difference in the percentage of

Clean Assembly of Genesis Collector Canister for Flight: Lessons for Planetary Sample Return

NASA Technical Reports Server (NTRS)

Allton, J. H.; Stansbery, E. K.; Allen, C. C.; Warren, J. L.; Schwartz, C. M.

2007-01-01

Measurement of solar composition in the Genesis collectors requires not only high sensitivity but very low blanks; thus, very strict collector contamination minimization was required beginning with mission planning and continuing through hardware design, fabrication, assembly and testing. Genesis started with clean collectors and kept them clean inside of a canister. The mounting hardware and container for the clean collectors were designed to be cleanable, with access to all surfaces for cleaning. Major structural components were made of aluminum and cleaned with megasonically energized ultrapure water (UPW). The UPW purity was >18 M resistivity. Although aluminum is relatively difficult to clean, the Genesis protocol achieved level 25 and level 50 cleanliness on large structural parts; however, the experience suggests that surface treatments may be helpful on future missions. All cleaning was performed in an ISO Class 4 (Class 10) cleanroom immediately adjacent to an ISO Class 4 assembly room; thus, no plastic packaging was required for transport. Persons assembling the canister were totally enclosed in cleanroom suits with face shield and HEPA filter exhaust from suit. Interior canister materials, including fasteners, were installed, untouched by gloves, using tweezers and other stainless steel tools. Sealants/lubricants were not exposed inside the canister, but vented to the exterior and applied in extremely small amounts using special tools. The canister was closed in ISO Class 4, not to be opened until on station at Earth-Sun L1. Throughout the cleaning and assembly, coupons of reference materials that were cleaned at the same time as the flight hardware were archived for future reference and blanks. Likewise reference collectors were archived. Post-mission analysis of collectors has made use of these archived reference materials.

Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

NASA Technical Reports Server (NTRS)

Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

2017-01-01

Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

Mechanistic, Mathematical Model to Predict the Dynamics of Tissue Genesis in Bone Defects via Mechanical Feedback and Mediation of Biochemical Factors

PubMed Central

Moore, Shannon R.; Saidel, Gerald M.; Knothe, Ulf; Knothe Tate, Melissa L.

2014-01-01

The link between mechanics and biology in the generation and the adaptation of bone has been well studied in context of skeletal development and fracture healing. Yet, the prediction of tissue genesis within - and the spatiotemporal healing of - postnatal defects, necessitates a quantitative evaluation of mechano-biological interactions using experimental and clinical parameters. To address this current gap in knowledge, this study aims to develop a mechanistic mathematical model of tissue genesis using bone morphogenetic protein (BMP) to represent of a class of factors that may coordinate bone healing. Specifically, we developed a mechanistic, mathematical model to predict the dynamics of tissue genesis by periosteal progenitor cells within a long bone defect surrounded by periosteum and stabilized via an intramedullary nail. The emergent material properties and mechanical environment associated with nascent tissue genesis influence the strain stimulus sensed by progenitor cells within the periosteum. Using a mechanical finite element model, periosteal surface strains are predicted as a function of emergent, nascent tissue properties. Strains are then input to a mechanistic mathematical model, where mechanical regulation of BMP-2 production mediates rates of cellular proliferation, differentiation and tissue production, to predict healing outcomes. A parametric approach enables the spatial and temporal prediction of endochondral tissue regeneration, assessed as areas of cartilage and mineralized bone, as functions of radial distance from the periosteum and time. Comparing model results to histological outcomes from two previous studies of periosteum-mediated bone regeneration in a common ovine model, it was shown that mechanistic models incorporating mechanical feedback successfully predict patterns (spatial) and trends (temporal) of bone tissue regeneration. The novel model framework presented here integrates a mechanistic feedback system based on the

Large-Scale Influences on the Genesis of Tropical Cyclone Karl (2010)

NASA Astrophysics Data System (ADS)

Griffin, K.; Bosart, L. F.

2012-12-01

The events leading up to the genesis of Tropical Cyclone (TC) Karl (2010) provides a unique opportunity to examine the continuing problem of understanding tropical cyclogenesis. The PRE-Depression Investigation of Cloud-systems in the Tropics (PREDICT) field campaign allowed for detailed investigation of the tropical disturbance that served as the precursor to TC Karl as it progressed westward through the Caribbean Sea. The purpose of this presentation is to examine the evolution of the pre-Karl disturbance using both common synoptic-scale analyses as well as statistically-based equatorial wave analyses, focusing on where these analyses complement and enhance each other. One of the major factors in the initial spin-up of the pre-Karl tropical disturbance is a surge of southerly and westerly winds from northern South America on 8-10 September 2010. As the surge entered the Caribbean on 9 September, it aided in the formation of a nearly closed earth-relative cyclonic circulation near the southern Leeward Islands. This circulation weakened late on 10 September and remained weak through 13 September before increased organization led to TC genesis on 14 September. This southerly wind surge can be traced to a well-defined surge of anomalously cold air and enhanced southerly winds originating in the lee of the Argentinian Andes over a week prior. While the temperature anomalies wash out prior to reaching the equator, anomalous low-level winds progress into Colombia and Venezuela, where topography aids in turning the southerly winds eastward. An investigation of the pre-Karl environment utilizing wavenumber-frequency filtering techniques also suggests that the initial spin-up of pre-Karl can be associated with the active phase of a convectively coupled Kelvin wave (CCKW). The observed formation of the nearly closed cyclonic circulation on 10 September is well timed with the passage of anomalous westerly winds along and behind the convectively active phase of a CCKW. These

Diagnosis of seasonal variations of tropical cyclogenesis over the South China Sea using a genesis potential index

NASA Astrophysics Data System (ADS)

Wang, Lei; Pan, Xiumei

2012-09-01

This study examines the seasonal variations of tropical cyclogenesis over the South China Sea (SCS) using a genesis potential (GP) index developed by Emanuel and Nolan. How different environmental factors (including low-level vorticity, mid-level relative humidity, vertical wind shear, and potential intensity) contribute to these variations is investigated. Composite anomalies of the GP index are produced for the summer and winter monsoons separately. These composites replicate the observed seasonal variations of the observed frequency and location of tropical cyclogenesis over the SCS. The degree of contribution by each factor in different regions is determined quantitatively by producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology. Over the northern SCS, potential intensity makes the largest contributions to the seasonal variations in tropical cyclogenesis. Over the southern SCS, the low-level relative vorticity plays the primary role in the seasonal modulation of tropical cyclone (TC) genesis frequency, and the vertical wind shear plays the secondary role. Thermodynamic factors play more important roles for the seasonal variations in tropical cyclogenesis over the northern SCS, while dynamic factors are more important in the seasonal modulation of TC genesis frequency over the southern SCS.

Petrologic comparisons of Cayley and Descartes on the basis of Apollo 16 soils from stations 4 and 11

NASA Technical Reports Server (NTRS)

Basu, A.; Mckay, D. S.

1984-01-01

Petrologic aspects of the Cayley and Descartes formations are reviewed in the light of new data on Apollo 16 soils. Specific comparison of the modal abundances of lithic fragments in drive tube sample 64001/2 from the slopes of Stone Mountain (station 4) and in soil 67941 from the North Ray Crater rim (station 11) shows that melt rocks, especially poikilitic rocks, are more abundant at station 4 than at station 11; the reverse is true for fragmental breccias. Such lithologic differences suggest that stations 4 and 11 do not belong to the same geologic formation. Metamorphosed breccias are pervasive in both the formations and may represent a local component that has been reworked and diluted as fresh materials were added. Lithologic compositions inferred from the study of soil samples are different from lithologic compositions inferred from the study of rake samples or breccia clasts. This difference may be related to a mixing of material of different grain size distributions. The petrology of soils at the Apollo 16 site may not accurately reflect original material associated with either the Descartes or the Cayley formation because of extensive mixing with local material.

The Genesis solar xenon composition and its relationship to planetary xenon signatures

NASA Astrophysics Data System (ADS)

Crowther, S. A.; Gilmour, J. D.

2013-12-01

The fluence and isotopic composition of solar wind xenon have been determined from silicon collector targets flown on the NASA Genesis mission. A protocol was developed to extract gas quantitatively from samples of ∼9-25 mm2, and xenon measured using the RELAX mass spectrometer. The fluence of implanted solar wind xenon is 1.202(87) × 106 atoms 132Xe cm-2, which equates to a flux of 5.14(21) × 106 atoms 132Xe cm-2 year-1 at the L1 point. This value is in good agreement with those reported in other studies. The isotopic composition of the solar wind is consistent with that extracted from the young lunar regolith and other Genesis collector targets. The more precise xenon isotopic data derived from the Genesis mission confirm models of relationships among planetary xenon signatures. The underlying composition of Xe-Q is mass fractionated solar wind; small, varying contributions of Xe-HL and 129Xe from 129I decay are present in reported meteorite analyses. In contrast, an s-process deficit is apparent in Xe-P3, which appears to have been mass fractionated to the same extent as Xe-Q from a precursor composition, suggesting similar trapping mechanisms. Solar wind xenon later evolved by the addition of ∼1% (at 132Xe) of s-process xenon to this precursor. As an alternative model to a single source reservoir for Xe-P3, we propose that trapping of xenon onto carbonaceous carriers has been an ongoing process across galactic history, and that preparation of the residues in which Xe-P3 has been identified preferentially preserves longer lived host phases; a higher proportion of these sample xenon isotopic compositions from earlier in galactic chemical evolution, allowing the s-process deficit to become apparent. The relationships among SW-Xe, Xe-Q and Xe-P3 predict that the 124Xe/132Xe ratio for the solar wind is 0.00481(6).

Ginsenoside Rb1 improves spatial learning and memory by regulation of cell genesis in the hippocampal subregions of rats.

PubMed

Liu, Lei; Hoang-Gia, Trinh; Wu, Hui; Lee, Mi-Ra; Gu, Lijuan; Wang, Chunyan; Yun, Beom-Sik; Wang, Qijun; Ye, Shengquan; Sung, Chang-Keun

2011-03-25

Ginsenoside Rb1 (Rb1) is known to improve learning and memory in hippocampus-dependent tasks. However, the cellular mechanism remains unknown. Cell genesis in hippocampus is involved in spatial learning and memory. In the present study, Rb1 was orally administrated to adult rats for 30days. The behavioral training tests indicated that Rb1 improved spatial cognitive performance of rats in Morris water maze (MWM). Furthermore, we investigated the effects of Rb1 on cell genesis in adult rats' hippocampus, using thymidine analog bromodeoxyuridine (BrdU) as a marker for dividing cells. It has been shown that hippocampal cell genesis can be influenced by several factors such as learning and exercise. In order to avoid the effects of the interfering factors, only the rats treated with Rb1 without training in MWM were used to investigate cell genesis in hippocampus. When BrdU was given to the rats 30days prior to being killed, it was shown that oral administration of Rb1 significantly increased cell survival in dentate gyrus and hippocampal subregion CA3. However, when BrdU was injected 2h prior to sacrifice, the results indicated that Rb1 had no significant influence on cell proliferation in the hippocampal subregions. Thus, an increase of cell survival in hippocampus stimulated by Rb1 may be one of the mechanisms by which ginseng facilitates spatial learning and memory. Our study also indicates that Rb1 may be developed as a therapeutic agent for patients with memory impairment. Copyright © 2011 Elsevier B.V. All rights reserved.

GENESIS: a hybrid-parallel and multi-scale molecular dynamics simulator with enhanced sampling algorithms for biomolecular and cellular simulations

PubMed Central

Jung, Jaewoon; Mori, Takaharu; Kobayashi, Chigusa; Matsunaga, Yasuhiro; Yoda, Takao; Feig, Michael; Sugita, Yuji

2015-01-01

GENESIS (Generalized-Ensemble Simulation System) is a new software package for molecular dynamics (MD) simulations of macromolecules. It has two MD simulators, called ATDYN and SPDYN. ATDYN is parallelized based on an atomic decomposition algorithm for the simulations of all-atom force-field models as well as coarse-grained Go-like models. SPDYN is highly parallelized based on a domain decomposition scheme, allowing large-scale MD simulations on supercomputers. Hybrid schemes combining OpenMP and MPI are used in both simulators to target modern multicore computer architectures. Key advantages of GENESIS are (1) the highly parallel performance of SPDYN for very large biological systems consisting of more than one million atoms and (2) the availability of various REMD algorithms (T-REMD, REUS, multi-dimensional REMD for both all-atom and Go-like models under the NVT, NPT, NPAT, and NPγT ensembles). The former is achieved by a combination of the midpoint cell method and the efficient three-dimensional Fast Fourier Transform algorithm, where the domain decomposition space is shared in real-space and reciprocal-space calculations. Other features in SPDYN, such as avoiding concurrent memory access, reducing communication times, and usage of parallel input/output files, also contribute to the performance. We show the REMD simulation results of a mixed (POPC/DMPC) lipid bilayer as a real application using GENESIS. GENESIS is released as free software under the GPLv2 licence and can be easily modified for the development of new algorithms and molecular models. WIREs Comput Mol Sci 2015, 5:310–323. doi: 10.1002/wcms.1220 PMID:26753008

GENESIS: a hybrid-parallel and multi-scale molecular dynamics simulator with enhanced sampling algorithms for biomolecular and cellular simulations.

PubMed

Jung, Jaewoon; Mori, Takaharu; Kobayashi, Chigusa; Matsunaga, Yasuhiro; Yoda, Takao; Feig, Michael; Sugita, Yuji

2015-07-01

GENESIS (Generalized-Ensemble Simulation System) is a new software package for molecular dynamics (MD) simulations of macromolecules. It has two MD simulators, called ATDYN and SPDYN. ATDYN is parallelized based on an atomic decomposition algorithm for the simulations of all-atom force-field models as well as coarse-grained Go-like models. SPDYN is highly parallelized based on a domain decomposition scheme, allowing large-scale MD simulations on supercomputers. Hybrid schemes combining OpenMP and MPI are used in both simulators to target modern multicore computer architectures. Key advantages of GENESIS are (1) the highly parallel performance of SPDYN for very large biological systems consisting of more than one million atoms and (2) the availability of various REMD algorithms (T-REMD, REUS, multi-dimensional REMD for both all-atom and Go-like models under the NVT, NPT, NPAT, and NPγT ensembles). The former is achieved by a combination of the midpoint cell method and the efficient three-dimensional Fast Fourier Transform algorithm, where the domain decomposition space is shared in real-space and reciprocal-space calculations. Other features in SPDYN, such as avoiding concurrent memory access, reducing communication times, and usage of parallel input/output files, also contribute to the performance. We show the REMD simulation results of a mixed (POPC/DMPC) lipid bilayer as a real application using GENESIS. GENESIS is released as free software under the GPLv2 licence and can be easily modified for the development of new algorithms and molecular models. WIREs Comput Mol Sci 2015, 5:310-323. doi: 10.1002/wcms.1220.

Petrology and chemistry of the Green Acres gabbro complex near Winchester, Riverside County, California

USGS Publications Warehouse

Berger, Byron R.; Morton, Douglas M.; Miller, Fred K.

2014-01-01

The Cretaceous Green Acres layered igneous complex, northeast of Winchester, California, is composed of a suite of olivine- and hornblende-bearing gabbros in the Peninsular Ranges batholith within the Perris tectonic block. A consistent mineral assemblage is observed throughout the complex, but there is considerable textural and modal heterogeneity. Both preclude a consistent set of principles based on appearance and mineralogy on which to delineate map units. Distinct changes in the chemistry of olivine, pyroxene, and hornblende, however, serve to define discrete mappable units, and the complex has been divided into five geochemical map units on this basis.Limited whole-rock data show the Green Acres complex is chemically comparable to other Peninsular Ranges batholith gabbroic rocks, and rare earth element (REE) concentrations and patterns are typical of magmas generated in convergent margin settings. For the complex as a whole, olivine is Fo80–35, plagioclase is An100–64, clinopyroxene is Wo49–41En48–38Fs18–6 and Wo36–26En65–42Fs30–8, and orthopyroxene is Wo5–0En78–42Fs50–21, where Fo is forsterite, An is anorthite, Wo is wollastonite, En is enstatite, and Fs is ferrosilite. The Mg/(Mg + ΣFe) atomic ratio in hornblende ranges from 0.84 to 0.50.Magmatic lineations and modal and textural layering are prevalent throughout the complex. Mineral chemistry does not change in any systematic way within and between layers in any map unit. Although the strike of layering varies, in any map unit at any given location it is the same in all units irrespective of intrusive order. Thin dikes, typically late-stage hornblende gabbro, commonly intrude parallel to layering. The strikes of magmatic lineations and modal layers are consistent with the populations of strikes of fabrics in the metamorphic basement as well as tectonic features in surrounding, postgabbro granitic rocks. These relations imply that the regional state of stress at the time of gabbro

Genesis and evolution of the Cerro Prieto Volcanic Complex, Baja California, Mexico

NASA Astrophysics Data System (ADS)

García-Sánchez, L.; Macías, J. L.; Sosa-Ceballos, G.; Arce, J. L.; Garduño-Monroy, V. H.; Saucedo, R.; Avellán, D. R.; Rangel, E.; Layer, P. W.; López-Loera, H.; Rocha, V. S.; Cisneros, G.; Reyes-Agustín, G.; Jiménez, A.; Benowitz, J. A.

2017-06-01

The Cerro Prieto Volcanic Complex (CPVC), located in northwestern Mexico, is the only surface manifestation of the Cerro Prieto Geothermal Field, the third largest producer of geothermal energy in the world. This geothermal field and the Salton Sea in the USA sit in a pull-apart basin that belongs to the trans-tensional tectonic zone that includes the San Andreas Fault system and the Salton Trough basin to the NW and the East Pacific Rise to the SE. In spite of its strategic importance in the generation of geothermal energy, the origin of Cerro Prieto and its relationship with the geothermal reservoir were unknown. In this contribution, we discuss the origin, evolution, and mechanisms of formation of this small monogenetic volcano and the magmas that fed the system. The volcanic complex is located on top of the Cerro Prieto left lateral fault to the northwest of the Cerro Prieto Geothermal Field. The complex consists of a lava cone and a series of domes (˜0.15 km3) protruding from Tertiary sandstones and recent unconsolidated sediments of the alluvial plain of the Colorado River. The Cerro Prieto Volcanic Complex consists of seven stratigraphic units emplaced in a brief time span around 78-81 ka. Its activity began with the extrusion of a dacitic lava that came into contact with water-saturated sediments, causing brecciation of the lava. The activity continued with the emplacement of dacitic domes and a dyke that were destroyed by a phreatic explosion emplacing a lithic-rich breccia. This phreatic explosion formed a 300-m-wide and 40-m-deep circular crater. The activity then migrated ˜650 m to the SW where three dacitic lava domes were extruded and ended with the emplacement of a fissure-fed lava flow. Subsequent remobilization of the rocks in the complex has generated debris and hyperconcentrated flow deposits interbedded with fluviatile sediments in the surrounding terrain. All rocks of the CPVC are dacites with phenocrysts of plagioclase, orthopyroxene, and Fe

Summary of the research work of the Trace Elements Section, Geochemistry and Petrology Branch, for the period January 1-March 31, 1951

USGS Publications Warehouse

Rabbitt, John C.

1951-01-01

This report summarized the research work of the Trace Elements Section, Geochemistry and Petrology Branch for the period January 1 - March 31, 1951. Work before that is summarized in an earlier report, "Summary of the research work of the Trace Elements Section, Geochemistry and Petrology Branch, for the period April 1, 1948 - December 31, 1950," by John C. Rabbitt (U.S. Geol. Survey Trace Elements Investigations Rept. 148, January 1951). This report will be referred to as TEIR 148. In TEIR 148 the purpose of each project was described and it is not thought necessary to repeat that material. The research work of the section consists of laboratory and related field studies in the following fields: 1. Mineralogic and petrologic investigations of radioactive rocks, minerals, and ores. 2. Investigations of chemical methods of analysis for uranium, thorium, and other elements and compounds in radioactive materials, and related chemical problems. 3. Investigations of spectographic method of analysis for a wide variety of elements in radioactive materials. 4. Investigation of radiometric methods of analysis is applied to radioactive materials. It should be emphasized that the work undertaken so far is almost entirely in the nature of investigations supporting the field appraisal of known uraniferous deposits. A program of more fundamental research, particularly in the mineralogy and geochemistry of uranium, is now being drawn up and will be submitted for approval soon. This report does not deal with the routine analytical work of the Section nor the public-sample program. The analytical work will be summarized in a report to be issued after the end of fiscal year 1951, and a report on the public-sample program is in process. Special thanks are due members of the Section who are engaged in the research work and who have supplied material for this report, the Early Ingerson, Chief of the Geochemistry and Petrology Branch for his critical review, to Jane Titcomb of the

Teaching Mineralogy, Petrology and Geochemistry in the 21st Century: Instructional Resources for Geoscience Faculty

NASA Astrophysics Data System (ADS)

Mogk, D. W.; Beane, R. J.; Whitney, D. L.; Nicolaysen, K. E.; Panero, W. R.; Peck, W. H.

2011-12-01

Mineralogy, petrology and geochemistry (MPG) are pillars of the geoscience curriculum because of their relevance in interpreting Earth history and processes, application to geo-hazards, resources, and environmental issues, and contributions to emerging fields such as geology and human health. To keep faculty current in scientific advances in these fields, and in modern instructional methods, the On the Cutting Edge program convened a workshop at the University of Minnesota in August, 2011. This workshop builds on the previous 15 year's work that has been focused on identifying, aggregating, and developing high-quality collections of teaching activities and related resources, and in building a community of scholars in support of excellence in instruction in MPG courses. The goals of the workshop were to: a) develop an integrated, comprehensive and reviewed curriculum for MPG courses, and to seek ways to make connections with the larger geoscience curriculum; b) to explore emerging topics in MPG such as geobiology and climate change; c) demonstrate effective methods in teaching MPG in the context of Earth system science; d) share effective teaching activities and strategies for the classroom, laboratory and field including advances in pedagogy, assessments and research on learning; e) keep faculty current on recent advances in mineralogy, petrology and geochemistry research and to apply these findings to our teaching; f) explore and utilize current societal and global issues that intersect mineralogy, petrology and geochemistry to heighten the relevancy of course content for students; and h) meet colleagues and foster future teaching and research collaborations. A significant outcome of this workshop is a peer reviewed of collection of 300+ existing teaching activities, and a gap analysis to identify teaching activities needed to make these collections comprehensive and coherent. In addition, a series of thematic collections were developed to assist high priority

Petrology, geochemistry and geochonology of the Jacupiranga ultramafic, alkaline and carbonatitic complex (southern Brazil)

NASA Astrophysics Data System (ADS)

Chmyz, Luanna; Arnaud, Nicolas; Biondi, João Carlos

2015-04-01

Brazilian carbonatitic complexes are located at the edges of the Paleozoic basins and are usually associated to tectonic crustal flexuring or deep fault zones. The Jacupiranga Complex is a 65 km² ultrabasic-alkaline carbonatitic intrusive body outcroping at the northeastern border of the Paraná Basin, South of São Paulo State (Brazil). The northern portion of the unit is mostly composed of peridotitic rocks, while the southern part contains ijolites, melteigites, clinopyroxenites and carbonatites which host a phosphate deposit, mined since 1966. Even though the carbonatites only represent 1% of the Complex's area, they have concentrated most of the historical petrogenetic studies, leaving almost unknown the petrogenetic and the geochronological characteristics of other rocks. This explains why the few petrogenetic models from the literature are very partial and mostly unsatisfactory. While the peridotitic rocks are largely hindered by the absence of fresh outcrops, the regolith thickness and the high serpentinization degree, field observations and petrographic data notably show a heterogeneous zone around the peridotitic body. That zone is composed of a large variety of lithotypes over a relatively small area (~9 km²), comprising diorites, monzodiorites, alkali feldspar syenites, trachytes, lamprophyres and syenites. Moreover, these rocks present a restricted lateral continuity (decametric) and a lack of the magmatic bedding characteristic of the ijolitic and clinopyroxenitc rocks. The southern clinopyroxenitic zone (~20 km²) is composed of clinopyroxenite and melteigite with prominent magmatic layering, probably of cumulative origin, and a body of carbonatites which outcrops over less than 1 km2 essentially composed of sovite and beforsite, with abundant apatite. The Jacupiranga Complex characteristics indicate that its formation possibly comprises at least five magmatic events which cannot at present be surely ordinated in time: a) the emplacement of the

An integrated model for the natural flow regime in the Cerro Prieto hydrothermal system based upon petrological and isotope geochemical criteria

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

Elders, W.A.; Williams, A.E.; Hoagland, J..

1981-01-01

Studies of cuttings and cores at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced.

Audio-magnetotelluric (AMT) study to investigate the genesis of Mujil hill

NASA Astrophysics Data System (ADS)

Rahmania, Suryanto, Wiwit

2017-07-01

Gunung Mujil is an isolated hill located near Pondoworejo village, Kalibawang sub-district, Kulon Progo district, and Special Province of Yogyakarta. The hill is part of the eastern Kulon Progo mountain range extended relatively in the North-South direction. The lithology of the hill consists of andesite breccia and it's similar with the Old Andesite Formation that built the Kulon Progo Mountains. There are at least two hypothesis about the genesis and the formation mechanism of this hill, (1) it was formed by debris mass from Kulon Progo Mountains, and (2) ) it was formed by an intrusion. Our study intended to determine the subsurface resistivity below the hill and to relating those results to with the scenario of the genesis of the Mujil hill. We conducted Audio-magnetotellurics (AMT) measurements along two lines survey crossing the Mujil hill consisting of 20 measurements. Since the measurements are located near the villages, most of the data has a fair to bad quality and only one station yielded an excellent data. A 1D Forward modeling was then applied to find best-fit model of the AMT data. The results shows that the Mujil hill was built by debris mass of the Old Andesite Formation from Kulon Progo mountain which is represented by a lower resistivity value under the Mujil hill.

DETERMINING THE ELEMENTAL AND ISOTOPIC COMPOSITION OF THE PRESOLAR NEBULA FROM GENESIS DATA ANALYSIS: THE CASE OF OXYGEN.

PubMed

Laming, J Martin; Heber, V S; Burnett, D S; Guan, Y; Hervig, R; Huss, G R; Jurewicz, A J G; Koeman-Shields, E C; McKeegan, K D; Nittler, L; Reisenfeld, D B; Rieck, K D; Wang, J; Wiens, R C; Woolum, D S

2017-12-10

We compare element and isotopic fractionations measured in solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We find mild support for an O abundance in the range 8.75 - 8.83, with a value as low as 8.69 disfavored. A stronger conclusion must await solar wind regime specific measurements from the Genesis samples.

Geochemistry of Rock Samples Collected from the Iron Hill Carbonatite Complex, Gunnison County, Colorado

USGS Publications Warehouse

Van Gosen, Bradley S.

2008-01-01

A study conducted in 2006 by the U.S. Geological Survey collected 57 surface rock samples from nine types of intrusive rock in the Iron Hill carbonatite complex. This intrusive complex, located in Gunnison County of southwestern Colorado, is known for its classic carbonatite-alkaline igneous geology and petrology. The Iron Hill complex is also noteworthy for its diverse mineral resources, including enrichments in titanium, rare earth elements, thorium, niobium (columbium), and vanadium. This study was performed to reexamine the chemistry and metallic content of the major rock units of the Iron Hill complex by using modern analytical techniques, while providing a broader suite of elements than the earlier published studies. The report contains the geochemical analyses of the samples in tabular and digital spreadsheet format, providing the analytical results for 55 major and trace elements.

Three Proposed Compendia for Genesis Solar Wind Samples: Science Results, Collector Materials Characterization and Cleaning Techniques

NASA Technical Reports Server (NTRS)

Allton, J. H.; Calaway, M. J.; Nyquist, L. E.; Jurewicz, A. J. G.; Burnett, D. S.

2018-01-01

Final Paper and not the abstract is attached. Introduction: Planetary material and cosmochemistry research using Genesis solar wind samples (including the development and implementation of cleaning and analytical techniques) has matured sufficiently that compilations on several topics, if made publically accessible, would be beneficial for researchers and reviewers. We propose here three compendia based on content, organization and source of documents (e.g. published peer-reviewed, published, internal memos, archives). For planning purposes, suggestions are solicited from potential users of Genesis solar wind samples for the type of science content and/or organizational style that would be most useful to them. These compendia are proposed as living documents, periodically updated. Similar to the existing compendia described below, the curation compendia are like library or archival finding aids, they are guides to published or archival documents and should not be cited as primary sources.

High-temperature carbonates in the Stillwater Complex, Montana, USA

NASA Astrophysics Data System (ADS)

Aird, H. M.; Boudreau, A. E.

2012-12-01

by Cl-rich fluids [4]. The association of high-temperature carbonates with sulphides beneath the J-M reef supports the hydromagmatic theory which involves a late-stage chloride-carbonate fluid percolating upwards, dissolving PGE and sulphides and redepositing them at a higher stratigraphic level. [1] Anovitz, L.M., and Essene, E.J., 1987, Phase Equilibria in the System CaCO3-MgCO3-FeCO3: Journal of Petrology, v. 28, p. 389-414. [2] Hanley, J.J., Mungall, J.E., Pettke, T., Spooner, E.T.C., and Bray, C.J., 2008, Fluid and Halide Melt Inclusions of Magmatic Origin in the Ultramafic and Lower Banded Series, Stillwater Complex, Montana, USA: Journal of Petrology, v. 49, p. 1133-1160. [3] Boudreau, A.E., and McCallum, I.S., 1989, Investigations of the Stillwater Complex: Part V. Apatites as indicators of evolving fluid composition: Contributions to Mineralogy and Petrology, v. 102, p. 138-153. [4] Newton, R.C., and Manning, C.E., 2002, Experimental determination of calcite solubility in H2O-NaCl solutions at deep crust/upper mantle pressures and temperature: implications for metasomatic processes in shear zones: American Mineralogist, v. 87, p. 1401-1409.

Using Image Pro Plus Software to Develop Particle Mapping on Genesis Solar Wind Collector Surfaces

NASA Technical Reports Server (NTRS)

Rodriquez, Melissa C.; Allton, J. H.; Burkett, P. J.

2012-01-01

The continued success of the Genesis mission science team in analyzing solar wind collector array samples is partially based on close collaboration of the JSC curation team with science team members who develop cleaning techniques and those who assess elemental cleanliness at the levels of detection. The goal of this collaboration is to develop a reservoir of solar wind collectors of known cleanliness to be available to investigators. The heart and driving force behind this effort is Genesis mission PI Don Burnett. While JSC contributes characterization, safe clean storage, and benign collector cleaning with ultrapure water (UPW) and UV ozone, Burnett has coordinated more exotic and rigorous cleaning which is contributed by science team members. He also coordinates cleanliness assessment requiring expertise and instruments not available in curation, such as XPS, TRXRF [1,2] and synchrotron TRXRF. JSC participates by optically documenting the particle distributions as cleaning steps progress. Thus, optical document supplements SEM imaging and analysis, and elemental assessment by TRXRF.

Bi-Parental Care Contributes to Sexually Dimorphic Neural Cell Genesis in the Adult Mammalian Brain

PubMed Central

Mak, Gloria K.; Antle, Michael C.; Dyck, Richard H.; Weiss, Samuel

2013-01-01

Early life events can modulate brain development to produce persistent physiological and behavioural phenotypes that are transmissible across generations. However, whether neural precursor cells are altered by early life events, to produce persistent and transmissible behavioural changes, is unknown. Here, we show that bi-parental care, in early life, increases neural cell genesis in the adult rodent brain in a sexually dimorphic manner. Bi-parentally raised male mice display enhanced adult dentate gyrus neurogenesis, which improves hippocampal neurogenesis-dependent learning and memory. Female mice display enhanced adult white matter oligodendrocyte production, which increases proficiency in bilateral motor coordination and preference for social investigation. Surprisingly, single parent-raised male and female offspring, whose fathers and mothers received bi-parental care, respectively, display a similar enhancement in adult neural cell genesis and phenotypic behaviour. Therefore, neural plasticity and behavioural effects due to bi-parental care persist throughout life and are transmitted to the next generation. PMID:23650527

The impact of Saharan Dust on the genesis and evolution of Hurricane Earl (2010)

NASA Astrophysics Data System (ADS)

Pan, B.; Wang, Y.; Hsieh, J. S.; Lin, Y.; Hu, J.; Zhang, R.

2017-12-01

Dust, one of the most abundant natural aerosols, can exert substantial radiative and microphysical effects on the regional climate and has potential impacts on the genesis and intensification of tropical cyclones (TCs). A Weather Research and Forecasting Model and the Regional Oceanic Modeling System coupled model (WRF-ROMS) is used to simulate the evolution of Hurricane Earl (2010), of which Earl was interfered by Saharan dust at the TC genesis stage. A new dust module has been implemented to the TAMU two-moment microphysics scheme in the WRF model. It accounts for both dust as Cloud Condensation Nuclei (CCN) and Ice Nuclei (IN). The hurricane track, intensity and precipitation have been compared to the best track data and TRMM precipitation, respectively. The influences of Saharan dust on Hurricane Earl are investigated with dust-CCN, dust-IN, and dust-free scenarios. The analysis shows that Saharan dust changes the latent heat and moisture distribution, invigorates the convections in the hurricane's eyewall, and suppresses the development of Earl. This finding addresses the importance of accounting dust microphysics effect on hurricane predictions.

Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils

NASA Astrophysics Data System (ADS)

Quantin, Paul

2010-05-01

Introduction. In Latinamerica, from Mexico to Chile, there are indurated volcanic soils horizons, named 'tepetate' in Mexico or cangahua in the Andes Mountains. Apart from original volcanic tuffs, these horizons were produced by pedogenesis: either through a former weathering of volcanic ash layers into fragic and later to petrocalcic horizons; or after a former soil formation through a second process of transformation from clayey volcanic soils to silicified petroduric horizons. This oral presentation will briefly deal with the formation of petroduric horizons in Mexico and petrocalcic horizon in Ecuador. Petroduric horizon genesis in Mexico. A soil climato-toposequence, near to Veracruz (Rossignol & Quantin, 1997), shows downwards an evolution from a ferralic Nitisol to a petroduric Durisol. A Durisol profile comports these successive horizons: at the top A and Eg, then columnar Btg-sim, laminar Bt-sim , prismatic Bsim, plinthite Cg, over andesite lava flow. Among its main features are especially recorded: clay mineralogy, microscopy and HRTEM. These data show: an increase in cristobalite at the expenses of 0.7 nm halloysite in Egsiltans, laminar Bt-sim, around or inside the columns or prisms of Btg-sim and Bsimhorizons. HRTEM (Elsass & al 2000) on ultra thin sections reveals an 'epigenesis' of clay sheets by amorphous silica, to form successively A-opal, Ct-opal and microcrystalline cristobalite. From these data and some groundwater chemical analyses, a scenario of duripan formation from a past clayey Nitisol is inferred: clay eluviation-illuviation process? alternate redoximorphy? clay degradation, Al leaching and Si accumulation, to form successively A-opal, Ct-opal and cristobalite. Petrocalcic horizon genesis in Ecuador. A soil climato-toposequence on pyroclastic flows, near to Bolivar in Ecuador (Quantin & Zebrowski, 1997), shows downwards the evolution from fragic-eutric-vitric Cambisols to petrocalcic-vitric Phaeozems, at the piedmont under semi

[Indices of pigment formation in complex cytomorphological research on human pigmented skin neoplasms].

PubMed

Naleskina, L A

1985-01-01

Analysis of the topography peculiarities and distribution of oxidized melanine and its precursors (DOPA-oxide activity and catecholamine) in pigment nevuses and malignant melanomas of skin shows that the studied peculiarities are a complex of intersupplementary markers of melanine formation, correlate with the quality and the degree of proliferative process expression in tumours of this genesis and may be used for their malignancy rating.

Sedimentary petrology and reservoir quality of the Middle Jurassic Red Glacier Formation, Cook Inlet forearc basin: Initial impressions

USGS Publications Warehouse

Helmold, K.P.; LePain, D.L.; Stanley, Richard G.

2016-01-01

The Division of Geological & Geophysical Surveys and Division of Oil & Gas are currently conducting a study of the hydrocarbon potential of Cook Inlet forearc basin (Gillis, 2013, 2014; LePain and others, 2013; Wartes, 2015; Herriott, 2016 [this volume]). The Middle Jurassic Tuxedni Group is recognized as a major source of oil in Tertiary reservoirs (Magoon, 1994), although the potential for Tuxedni reservoirs remains largely unknown. As part of this program, five days of the 2015 field season were spent examining outcrops, largely sandstones, of the Middle Jurassic Red Glacier Formation (Tuxedni Group) approximately 6.4 km northeast of Johnson Glacier on the western side of Cook Inlet (fig. 4-1). Three stratigraphic sections (fig. 4-2) totaling approximately 307 m in thickness were measured and described in detail (LePain and others, 2016 [this volume]). Samples were collected for a variety of analyses including palynology, Rock-Eval pyrolysis, vitrinite reflectance, detrital zircon geochronology, and petrology. This report summarizes our initial impressions of the petrology and reservoir quality of sandstones encountered in these measured sections. Interpretations are based largely on hand-lens observations of hand specimens and are augmented by stereomicroscope observations. Detailed petrographic (point-count) analyses and measurement of petrophysical properties (porosity, permeability, and grain density) are currently in progress.

Radio-induced alteration in cordierite - Implications for petrology, gemmology and materials science

NASA Astrophysics Data System (ADS)

Krickl, R.; Nasdala, L.; Grambole, D.; Kaindl, R.

2009-04-01

Cordierite is a common metamorphic and magmatic mineral, which is used as petrologic tool for reconstructing the history of its host rock. Further applications include cordierite gemstones and the use of synthetic analogs in ceramics. Cordierite is stable over a wide temperature and pressure range and relatively resistant to chemical alteration; however, its properties can be significantly changed upon the impact of external irradiation. In the course of a comprehensive study, natural radiohaloes in cordierite (a widespread feature caused by the impact of alpha-particles originating from radioactive inclusions) as well as artificial analogs produced by implantation of 8.8 MeV He2+ ions were investigated using modern micro-techniques. Additional irradiation experiments were performed using O6+ ions, electrons and gamma-rays. Ion irradiation causes yellow colouration that is strongly pleochroic, and fades at higher doses. The possibility of radiation-treatment for enhancing the quality of gem-cordierite is discussed. While samples remain crystalline up to doses of 1016 He2+/cm2, the same material is fully amorphised when irradiated with the same dose of 30 MeV O6+ ions. These different observations may help to estimate the performance assessment of cordierite-ceramics in radiated environments. A very important result concerning the petrological use of cordierite is the radio-induced transformation of channel constituents: Inside the irradiated areas the vibrational bands of CO2 decrease in intensity, whereas two new bands appear at 2135 cm-1 (both IR- and Raman-active; cf. Nasdala et al., 2006) and 1550 cm-1 (only Raman-activ). They are assigned to stretching vibrations of carbon monoxide and molecular oxygen, respectively, thus indicating a radio-chemical transformation 2CO2 → 2CO + O2 in alpha-irradiated cordierite. This study yields the first spectroscopic evidence for the irradiation-induced formation of molecular oxygen in cordierite. Polarised vibrational

Large-Scale Professional Development towards Emancipatory Mathematics: The Genesis of YuMi Deadly Maths

ERIC Educational Resources Information Center

Cooper, Tom; Carter, Merilyn

2016-01-01

This paper describes the genesis of YuMi Deadly Maths, a school change process that has been used in over 200 schools to develop mathematics teaching and learning to improve students' employment and life chances. The paper discusses the YuMi Deadly Maths approach to mathematics content and pedagogy, implemented through a process of PD and school…

Tropical cyclone genesis potential index over the western North Pacific simulated by CMIP5 models

NASA Astrophysics Data System (ADS)

Song, Yajuan; Wang, Lei; Lei, Xiaoyan; Wang, Xidong

2015-11-01

Tropical cyclone (TC) genesis over the western North Pacific (WNP) is analyzed using 23 CMIP5 (Coupled Model Intercomparison Project Phase 5) models and reanalysis datasets. The models are evaluated according to TC genesis potential index (GPI). The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets (ERA-Interim, NCEP/NCAR Reanalysis-1, and NCEP/DOE Reanalysis-2). Spatial distributions of July-October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTrACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982-2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multimodel ensemble (MME) mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20°N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982-1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21st century, and then starts to decrease at the end of the 21st century under the representative concentration pathway (RCP) 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of 20°N, indicating more TCs could possibly be expected over the WNP under future global warming.

Petrology and chemistry of Jebel Tanumah complex, Khamis Mushayt, Southern Arabian shield, Saudi Arabia

NASA Astrophysics Data System (ADS)

Nassief, M. O.; Ali, H. M.; Zakir, F. A.

The mafic intrusive complex at Jebel Tanumah is located 15 km north-west of Khamis Mushayt in the southern Arabian Shield and includes olivine-bearing gabbro as well as amphibole-diopside-hornblende gabbro cumulates. These rocks have been generally metamorphosed to upper greeenschist-lower amphibolite facies. Fourteen white rock silicate analyses indicate that the majority of the rocks are calc-alkaline to tholeiitic in composition. The two major structural units in the Khamis Mushayt region identified by Coleman consist of the basement complex of Asir Mountains and the younger metamorphic rocks. Syntectonic granitic rocks intruded the antiforms characterizing the younger rocks whereas the lower parts of the synforms are intruded by post-tectonic intrusions of layered gabbros such as the one studied at Jebel Tanumah.

A New Perspective on El Niño Diversity and Its Genesis

NASA Astrophysics Data System (ADS)

Chen, D.

2015-12-01

El Niño is by far the most energetic and influential interannual fluctuation in the Earth's climate system. Despite the tremendous progress in the theory, observation and prediction of El Niño over the past three decades, there is still considerable debate on the classification of El Niño diversity and on the genesis of such diversity. This uncertainty renders El Niño prediction a continuously challenging task. Here we provide a unified perspective on El Niño diversity as well as its causes, based on a fuzzy clustering analysis and model experiments. Specifically, the interannual variability of the tropical Pacific sea surface temperature can be generally classified into three warm patterns and one cold pattern, which together constitute a canonical El Niño/La Niña cycle and its different flavors. Whereas the genesis of the canonical cycle can be readily explained by classic theories, the asymmetry, irregularity and extremes of El Niño may well result from westerly wind bursts, a type of state-dependent atmospheric perturbation in the equatorial Pacific, which strongly affects El Niño but not La Niña due to its unidirectional nature. This suggests that properly accounting for the interplay between the canonical cycle and westerly wind bursts may improve El Niño prediction.

Alu repeats: A source for the genesis of primate microsatellites

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

Arcot, S.S.; Batzer, M.A.; Wang, Zhenyuan

1995-09-01

As a result of their abundance, relatively uniform distribution, and high degree of polymorphism, microsatellites and minisatellites have become valuable tools in genetic mapping, forensic identity testing, and population studies. In recent years, a number of microsatellite repeats have been found to be associated with Alu interspersed repeated DNA elements. The association of an Alu element with a microsatellite repeat could result from the integration of an Alu element within a preexisting microsatellite repeat. Alternatively, Alu elements could have a direct role in the origin of microsatellite repeats. Errors introduced during reverse transcription of the primary transcript derived from anmore » Alu {open_quotes}master{close_quote} gene or the accumulation of random mutations in the middle A-rich regions and oligo(dA)-rich tails of Alu elements after insertion and subsequent expansion and contraction of these sequences could result in the genesis of a microsatellite repeat. We have tested these hypotheses by a direct evolutionary comparison of the sequences of some recent Alu elements that are found only in humans and are absent from nonhuman primates, as well as some older Alu elements that are present at orthologous positions in a number of nonhuman primates. The origin of {open_quotes}young{close_quotes} Alu insertions, absence of sequences that resemble microsatellite repeats at the orthologous loci in chimpanzees, and the gradual expansion of microsatellite repeats in some old Alu repeats at orthologous positions within the genomes of a number of nonhuman primates suggest that Alu elements are a source for the genesis of primate microsatellite repeats. 48 refs., 5 figs., 3 tabs.« less

Seismic and petrological properties of the upper mantle between 300 and 400 km depth

NASA Astrophysics Data System (ADS)

Perchuc, E.; Malinowski, M.; Nita, B.

2008-12-01

We compare the traveltime data from the long range seismic profiles and from the earthquakes recorded to the offset of 3000 km with theoretical traveltimes predicted by standard seismological models: PREM, IASP- 91, AK-135 and especially from seismo-petrological model PREF (Cammarano and Romanowicz - 2007). We try to compare our models to earlier studies by Thybo and Perchuc (1997a). Our data suggests that for several events in the distance range 2000-2800 km, the first-arrivals are characterized by a relatively high velocity of 8.7-8.9 km/s. It is about 2.5% higher than P-wave velocity of the Lehmann phases, observed in the nearest offset and about 3% smaller than velocity below 410 km discontinuity. We suggest that this is a new first-order seismological boundary which can be interpreted as a top of the mantle transition zone. Seismological arguments for the existence of such a boundary are as follows: refracted waves with velocity 8.7-8.9 km/s and reflected waves find by Warren at al. (1967) and by Thybo and Perchuc (1997b). Also the interpretation of the SS precursor phases (Deuss and Woodhouse 2002) suggested a reflection boundary around 300 km (our interpretation). Depth of this boundary strongly depends on the thermal state of the mantle in particular regions. In conclusion we can say that the mantle transition zone starts much earlier and the lower part of the upper mantle is much faster than predicted by purely pyrolitic mantle model. Several petrological studies suggest influences of fluids (especialy H2O) on the character of the 410 km discontinuity and of the transition zone. All the differences in experimental data can be explained by the effect of temperature on the phase transformations within the olivine-wadsleyite system.

Tropical Cyclone Genesis: A Dynamician's Point of View

NASA Astrophysics Data System (ADS)

Bouali, Safieddine; Leys, Jos

The paper focuses the route to the maturity of a cyclone as a twist process of the Hadley cell. The approach is qualified by a "dynamician's viewpoint" since the aerologic mechanism of the cyclone genesis is replicated without the classical tools of the meteorological fluid framework. Indeed, we introduce a pure dynamical model of a 2D vertical rotor of an airparcel to emulate the Hadley cell. Twisted by an appropriate feedback to inject geophysical forcing, the simulation displays two stretched solenoid rolls with clockwise and anticlockwise paths representing the Hadley belts wrapping the Earth. When the forcing parameter is higher, computations simulate overlapped whirlwind funnels revealing strong similarities with the structure of cyclones, hurricanes, and typhoons described in the atmospheric science literature. We conjecture that ocean-atmosphere interactions separate and convert a "slice" of the Hadley rotor into a fully tropical cyclone.

Helium, neon, and argon composition of the solar wind as recorded in gold and other Genesis collector materials

NASA Astrophysics Data System (ADS)

Pepin, Robert O.; Schlutter, Dennis J.; Becker, Richard H.; Reisenfeld, Daniel B.

2012-07-01

We report compositions and fluxes of light noble gases in the solar wind (SW), extracted by stepped pyrolysis and amalgamation from gold collector materials carried on the Genesis Solar Wind Sample Return Mission. Results are compared with data from other laboratories on SW-He, Ne and Ar distributions implanted in Genesis aluminum, carbon, and silicon collectors and extracted by laser ablation. Corrections for mass-dependent losses (“backscatter”) of impinging SW ions due to scattering from the collector material are substantially larger for gold than for these lower atomic weight targets. We assess such losses by SRIM simulation calculations of SW backscatter from gold which are applied to the measurements to recover the composition of the incident SW. Averaged results of integrated stepped pyrolysis and single-step amalgamation measurements, with 1σ errors, are as follows: for SW-Ne and Ar isotope ratios (3He/4He was not measured), 20Ne/22Ne = 14.001 ± 0.042, 21Ne/22Ne = 0.03361 ± 0.00018, 36Ar/38Ar = 5.501 ± 0.014; for SW element ratios, 4He/20Ne = 641 ± 15, 20Ne/36Ar = 51.6 ± 0.5; and for SW fluxes in atoms cm-2 s-1 at the Genesis L1 station, 4He = 1.14 ± 0.04 × 107, 20Ne = 1.80 ± 0.06 × 104, 36Ar = 3.58 ± 0.11 × 102. Except for the 21Ne/22Ne and 20Ne/36Ar ratios, these values are in reasonable accord (within ∼1-3σ) with measurements on different collector materials reported by one or both of two other Genesis noble gas research groups. We further find, in three stepped pyrolysis experiments on gold foil, that He, Ne and Ar are released at increasing temperatures without elemental fractionation, in contrast to a pyrolytic extraction of a single non-gold collector (Al) where the release patterns point to mass-dependent thermal diffusion. The pyrolyzed gold foils exhibit enhancements, relative to sample totals, in 20Ne/22Ne and 21Ne/22Ne ratios evolved at low temperatures. The absence of elemental fractionation in pyrolytic release from gold

Maneuver Design and Calibration for the Genesis Spacecraft

NASA Technical Reports Server (NTRS)

Williams, Kenneth E.; Hong, Philip E.; Zietz, Richard P.; Han, Don

2000-01-01

Genesis is the fifth mission selected as part of NASA's Discovery Program. The objective of Genesis is to collect solar wind samples for a period of approximately two years while in a halo orbit about the Earth-Sun L I point. At the end of this period, the samples are to be returned to a specific recovery point on the Earth for subsequent analysis. This goal has never been attempted before and presents a formidable challenge in terms of mission design and operations, particularly planning and execution of propulsive maneuvers. To achieve a level of cost-effectiveness consistent with a Discovery-class mission, the Genesis spacecraft design was adapted to the maximum extent possible from designs used on earlier missions, such as Mars Global Surveyor (MGS) and Stardust, another sample collection mission. The spacecraft design for Genesis is shown. Spin stabilization was chosen for attitude control, in lieu of three-axis stabilization, with neither reaction wheels nor accelerometers included. This precludes closed-loop control of propulsive maneuvers and implies that any attitude changes, including spin changes and precessions, will behave like translational propulsive maneuvers and affect the spacecraft trajectory. Moreover, to minimize contamination risk to the samples collected, all thrusters were placed on the side opposite the sample collection canister. The orientation and characteristics of thrusters are indicated. For large maneuvers (>2.5 m/s), two 5 lbf thrusters will be used for delta v, with precession to the burn attitude, followed by spin-up from 1.6 to 10 rpm before the burn and spin down to 1.6 rpm afterwards, then precession back to the original spin attitude. For small maneuvers (<2.5 m/s), no spin change is needed and four 0.2 lbf thrusters are used for Av. Single or double 360 deg. precession changes are required whenever the desired delta v falls inside the two-way turn circle (about 0.4 m/s) based on the mass properties, spin rate and lever arm

Evolution of Pleistocene to Holocene eruptions in the Lesser Caucasus Mts:Insights from geology, petrology, geochemistry and geochronology

NASA Astrophysics Data System (ADS)

Savov, Ivan; Meliksetian, Khachatur; Connor, Charles; Karakhanian, Arkadi; Sugden, Patrick; Navasardyan, Gevorg; Halama, Ralf; Ishizuka, Osamu; Connor, Laura; Karapetian, Sergei

2016-04-01

Both effusive and highly explosive (VEI>5) and often voluminous caldera volcanism has developed atop the collision zone between the Arabian and the Eurasian plates. Currently what is exposed on the Anatolian-Armenian-Iranian active orogenic plateau is post-Mesozoic felsic to intermediate collision-related plutons, and mostly collision or post-collision related Quaternary volcanic structures. We have studied in detail the volcanism, tectonics and geophysics on the territory of E.Turkey and Armenia, where several large stratovolcanoes (Ararat, Lesser Ararat, Aragats, Tsghuk, Ishkhanasar) are surrounded by distinct monogenetic volcanic fields (distributed volcanism). These large in volume stratovolcanoes and the associated low volume monogenetic cones range from normal calk-alkaline to high-K shoshonitic in affinity, with their products ranging from basanites to high K trachytes and rhyolites. Several volcanic provinces, namely Kechut/Javakheti, Aragats, Gegham, Vardenis and Syunik are recognized in Armenia and each of them has > 100 mapped volcanoes. These have distinct geochemical (mineral chemistry, trace element and Sr-Nd-B isotope systematics) and petrological (melt eruption temperatures and volatile contents) fingerprints that may or may not vary over time. Age determinations and volcano-stratigraphy sections for each of the case studies we aim to present shows that the volcanism includes a continuous record from Pleistocene to Holocene, or even historical eruptions. The excellent volcano exposures and the now complete high resolution database (GIS), geological mapping, and new and improved K-Ar and Ar-Ar geochronology, uniquely allows us to evaluate the driving forces behind the volcanism in this continent-continent collision setting that is uniquely associated with long lasting eruption episodes. We shall compare the now well studied historical/Holocene eruptions with those pre-dating them, with the aim to identify possible geochemical or petrological

Geophysical and petrological characterization of the lithospheric mantle in Iberia, Western Mediterranean and North Africa

NASA Astrophysics Data System (ADS)

Fernandez, M.; Torne, M.; Carballo, A.; Jiménez-Munt, I.; Verges, J.; Villasenor, A.; Garcia-Castellanos, D.; Diaz Cusi, J.

2015-12-01

We present a geophysical and petrological study that aims to define the lithosphere structure and the variations of the chemical composition of the lithospheric mantle along three geo-transects crossing Iberia, the westernmost Mediterranean and North Africa. The modeling is based on an integrated geophysical-petrological methodology that combines elevation, gravity, geoid, surface heat flow, seismic and geochemical data. Unlike previous models, where the density of the lithospheric mantle is only temperature-dependent, the applied methodology allows inferring seismic velocities and density in the mantle down to 400 km depth from its chemical composition through self-consistent thermodynamic calculations. The first geo-transect with a length of 1100 km runs from the NE-Iberian Peninsula to the Tell-Atlas Mountains in Algeria. The second profile crosses the entire Iberian Peninsula, from the Northern Iberian Margin to the Alboran Basin. The third runs from the Iberian Massif to the Sahara Platform crossing the Betic-Rif orogenic system through the Gibraltar Strait and the Atlas Mountains. Results are compared to available tomography models and Pn-velocity data. The obtained lithospheric structure shows large lateral variations in crustal and lithospheric mantle thicknesses and mantle chemical composition. Measured low Pn velocities in the Western Mediterranean basin can be explained either by serpentinization and/or seismic anisotropy and only partly by transient thermal effects. In the Bay of Biscay low Pn velocities are explained only by serpentinization. The negative sub-lithospheric velocity anomalies imaged by tomography models below the Iberian plate and the Atlas Mountains are interpreted in terms of high-temperature/low-density regions being responsible for the high mean topography.

Potential Vorticity Streamers as Precursors to Tropical Cyclone Genesis in the Western Pacific

DTIC Science & Technology

2012-03-01

study a developing system with an extratropical precursor (TCS-037) developing into Tropical Storm 16W (TS 16W)” (Schönenberger 2010). This subsection...tropopause maps), the TC genesis event is termed a tropical transition (TT) case. If no such extratropical feature 38 is present, the storm in... extratropical origin is deemed to play an important role in the dynamical evolution leading to tropical cyclogenesis. In contrast, non-TT storms

76 FR 21403 - Notice of Availability of the Final Environmental Impact Statement for the Genesis Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-15

.... Idaho Street, Elko, Nevada during regular business hours of 7:30 a.m. to 4:30 p.m., Monday through... to contact the above individual during normal business hours. The FIRS is available 24 hours a day, 7... normal business hours. SUPPLEMENTARY INFORMATION: Newmont Mining Corporation's Genesis- Bluestar mining...

Determining the Elemental and Isotopic Composition of the Pre-solar Nebula from Genesis Data Analysis: The Case of Oxygen

DOE PAGES

Laming, J. Martin; Heber, Veronika S.; Burnett, Donald S.; ...

2017-12-06

Here, we compare element and isotopic fractionations measured in bulk solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We also find mild support for an O abundance in the range 8.75–8.83, with a value as low as 8.69 disfavored. Amore » stronger conclusion must await solar wind regime-specific measurements from the Genesis samples.« less

Determining the Elemental and Isotopic Composition of the Pre-solar Nebula from Genesis Data Analysis: The Case of Oxygen

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

Laming, J. Martin; Heber, Veronika S.; Burnett, Donald S.

Here, we compare element and isotopic fractionations measured in bulk solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We also find mild support for an O abundance in the range 8.75–8.83, with a value as low as 8.69 disfavored. Amore » stronger conclusion must await solar wind regime-specific measurements from the Genesis samples.« less

A Genesis breakup and burnup analysis in off-nominal Earth return and atmospheric entry

NASA Technical Reports Server (NTRS)

Salama, Ahmed; Ling, Lisa; McRonald, Angus

2005-01-01

The Genesis project conducted a detailed breakup/burnup analysis before the Earth return to determine if any spacecraft component could survive and reach the ground intact in case of an off-nominal entry. In addition, an independent JPL team was chartered with the responsibility of analyzing several definitive breakup scenarios to verify the official project analysis. This paper presents the analysis and results of this independent team.

Progress in 1988 1990 with computer applications in the ``hard-rock'' arena: Geochemistry, mineralogy, petrology, and volcanology

NASA Astrophysics Data System (ADS)

Rock, Nicholas M. S.

This review covers rock, mineral and isotope geochemistry, mineralogy, igneous and metamorphic petrology, and volcanology. Crystallography, exploration geochemistry, and mineral exploration are excluded. Fairly extended comments on software availability, and on computerization of the publication process and of specimen collection indexes, may interest a wider audience. A proliferation of both published and commercial software in the past 3 years indicates increasing interest in what traditionally has been a rather reluctant sphere of geoscience computer activity. However, much of this software duplicates the same old functions (Harker and triangular plots, mineral recalculations, etc.). It usually is more efficient nowadays to use someone else's program, or to employ the command language in one of many general-purpose spreadsheet or statistical packages available, than to program a specialist operation from scratch in, say, FORTRAN. Greatest activity has been in mineralogy, where several journals specifically encourage publication of computer-related activities, and IMA and MSA Working Groups on microcomputers have been convened. In petrology and geochemistry, large national databases of rock and mineral analyses continue to multiply, whereas the international database IGBA grows slowly; some form of integration is necessary to make these disparate systems of lasting value to the global "hard-rock" community. Total merging or separate addressing via an intelligent "front-end" are both possibilities. In volcanology, the BBC's videodisk Volcanoes and the Smithsonian Institution's Global Volcanism Project use the most up-to-date computer technology in an exciting and innovative way, to promote public education.

A 15N-poor isotopic composition for the solar system as shown by Genesis solar wind samples.

PubMed

Marty, B; Chaussidon, M; Wiens, R C; Jurewicz, A J G; Burnett, D S

2011-06-24

The Genesis mission sampled solar wind ions to document the elemental and isotopic compositions of the Sun and, by inference, of the protosolar nebula. Nitrogen was a key target element because the extent and origin of its isotopic variations in solar system materials remain unknown. Isotopic analysis of a Genesis Solar Wind Concentrator target material shows that implanted solar wind nitrogen has a (15)N/(14)N ratio of 2.18 ± 0.02 × 10(-3) (that is, ≈40% poorer in (15)N relative to terrestrial atmosphere). The (15)N/(14)N ratio of the protosolar nebula was 2.27 ± 0.03 × 10(-3), which is the lowest (15)N/(14)N ratio known for solar system objects. This result demonstrates the extreme nitrogen isotopic heterogeneity of the nascent solar system and accounts for the (15)N-depleted components observed in solar system reservoirs.

Seasonal prediction of the typhoon genesis frequency over the Western North Pacific with a Poisson regression model

NASA Astrophysics Data System (ADS)

Zhang, Xinchang; Zhong, Shanshan; Wu, Zhiwei; Li, Yun

2017-06-01

This study investigates the typhoon genesis frequency (TGF) in the dominant season (July to October) in Western North Pacific (WNP) using observed data in 1965-2015. Of particular interest is the predictability of the TGF and associated preseason sea surface temperature (SST) in the Pacific. It is found that, the TGF is positively related to a tri-polar pattern of April SST anomalies in North Pacific (NP{T}_{Apr}), while it is negatively related to SST anomalies over the Coral Sea (CSS{T}_{Apr}) off east coast of Australia. The NP{T}_{Apr} leads to large anomalous cyclonic circulation over North Pacific. The anomalous southwesterly weakens the northeast trade wind, decreases evaporation, and induces warm water in central tropical North Pacific. As such, the warming effect amplifies the temperature gradient in central tropical North Pacific, which in turn maintains the cyclonic wind anomaly in the west tropical Pacific, which favors the typhoon genesis in WNP. In the South Pacific, the CSS{T}_{Apr} supports the typhoon formation over the WNP by (a) strengthening the cross-equatorial flows and enhancing the Inter-tropical Convergence Zone; (b) weakening southeast and northeast trade wind, and keeping continuous warming in the center of tropical Pacific. The influence of both NP{T}_{Apr} and CSS{T}_{Apr} can persistently affect the zonal wind in the tropical Pacific and induce conditions favorable for the typhoon genesis in the typhoon season. A Poisson regression model using NP{T}_{Apr} and CSS}{T}_{Apr} is developed to predict the TGF and a promising skill is achieved.

South-Tibetan partially molten batholiths: geophysical characterization and petrological assessment of their origin

NASA Astrophysics Data System (ADS)

Hetényi, G.; Pistone, M.; Nabelek, P. I.; Baumgartner, L. P.

2017-12-01

Zones of partial melt in the middle crust of Lhasa Block, Southern Tibet, have been geophysically observed as seismically reflective "bright spots" in the past 20 years. These batholiths bear important relevance for geodynamics as they serve as the principal observation at depth supporting channel-flow models in the Himalaya-Tibet orogen. Here we assess the spatial abundance of and partial melt volume fraction within these crustal batholiths, and establish lower and upper estimate bounds using a joint geophysical-petrological approach.Geophysical imaging constrains the abundance of partial melt zones to 5.6 km3 per surface-km2 on average (minimum: 3.1 km3/km2, maximum: 7.6 km3/km2 over the mapped area). Physical properties detected by field geophysics and interpreted by laboratory measurements constrain the amount of partial melt to be between 5 and 26 percent.We evaluate the compatibility of these estimates with petrological modeling based on geotherms, crustal bulk rock compositions and water contents consistent with the Lhasa Block. These simulations determine: (a) the physico-chemical conditions of melt generation at the base of the Tibetan crust and its transport and emplacement in the middle crust; (b) the melt percentage produced at the source, transported and emplaced to form the observed "bright spots". Two main mechanisms are considered: (1) melting induced by fluids produced during mineral dehydration reactions in the underthrusting Indian lower crust; (2) dehydration-melting reactions caused by heating within the Tibetan crust. We find that both mechanisms demonstrate first-order match in explaining the formation of the partially molten "bright spots". Thermal modelling shows that the Lhasa Block batholiths have only small amounts of melt and only for geologically short times (<4.5 Myr), if not continuously fed. This, together with their small size compared to the Tibetan Plateau, suggests that these partially molten zones are ephemeral and local

Unraveling the Alteration History of Serpentinites and Associated Ultramafic Rocks from the Kampos HPLT Subduction Complex, Syros, Greece

NASA Astrophysics Data System (ADS)

Cooperdock, E. H. G.; Stockli, D. F.

2016-12-01

Serpentinization, hydration of peridotite, has a profound effect on fundamental tectonic and petrologic processes such as deformation of the lithosphere, bulk rheology, fluid-mobile element cycling and deep earth carbon cycling. Though numerous studies have investigated the petrology, structure and geochemistry of serpentinites, the absolute chronology of serpentinization remains elusive due to a lack of accessory minerals that can be dated using established geochronological techniques. Magnetite forms as a common secondary mineral in serpentinites from the fluid-induced breakdown reaction of primary peridotite minerals. Magnetite (U-Th)/He chronometry provides the potential to directly date the cooling of exhumed ultramafic bodies and the low-temperature fluid alteration of serpentinites. We present the first application of magnetite (U-Th)/He chronometry to date stages of alteration in ultramafic rocks from the Kampos mélange belt, a high-pressure low-temperature (HP-LT) subduction complex that experienced exhumation in the Miocene on the island of Syros, Greece. Two generations of magnetite are distinguishable by grain size, magnetite trace element geochemistry and (U-Th)/He age. Large magnetite grains (mm) from a chlorite schist and a serpentinite schist have distinct geochemical signatures indicative of formation during blackwall-related fluid alteration and record Mid-Miocene exhumation-related cooling ages, similar to zircon (U-Th)/He ages from northern Syros. Smaller grains (µm) from the serpentinite schist lack blackwall-related fluid signatures and record post-exhumation mineral formation associated with widespread high-angle Pliocene normal faulting. These results reveal evidence for multiple episodes of fluid-rock alteration, which has implications for the cooling history and local geochemical exchanges of this HP-LT terrane. Given the fundamental impact of serpentinizaton on a vast array of tectonic, petrological, and geochemical processes, the

Redesigning Task Sequences to Support Instrumental Genesis in the Use of Movable Points and Slider Bars

ERIC Educational Resources Information Center

Fahlgren, Maria

2017-01-01

This paper examines the process of instrumental genesis through which students develop their proficiency in making use of movable points and slider bars--two tools that dynamic mathematics software provides for working with variable coordinates and parameters in the field of functions. The paper analyses students' responses to task sequences…

Presentations - Lande, Lauren and others, 2015 | Alaska Division of

Science.gov Websites

Details Title: A petrological model for emplacement of the ultramafic Ni-Cu-PGE Alpha complex, eastern , Newberry, R.J., and Twelker, Evan, 2015, A petrological model for emplacement of the ultramafic Ni-Cu-PGE Sheets Maps & Other Oversized Sheets Sheet 1 A petrological model for emplacement of the ultramafic

Studies of Brazilian meteorites. XIII - Mineralogy, petrology, and chemistry of the Putinga, Rio Grande do Sul, chondrite

NASA Technical Reports Server (NTRS)

Keil, K.; Lange, D.; Ulbrich, M. N. C.; Gomes, C. B.; Jarosewich, E.; Roisenberg, A.; Souza, M. J.

1978-01-01

The Putinga, Rio Grande do Sul chondrite is described and classified as an L6. The mineral composition and some significant ratios of elements are reported, and the reasons for assignment to the L group and to petrologic type 6 are explained. The analysis suggests that maskelynite of oligoclase composition was formed by solid-state shock transformation of previously existing well-crystallized plagioclase at estimated shock pressures of about 250-350 kbar. This finding indicates that recrystallization (formation of well-crystallized oligoclase) preceded shock transformation formation of the maskelynite.

Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity

PubMed Central

Liu, Baohui; Lin, Xi; Yang, Xiangsheng; Dong, Huimin; Yue, Xiaojing; Andrade, Kelsey C; Guo, Zhentao; Yang, Jian; Wu, Liquan; Zhu, Xiaonan; Zhang, Shenqi; Tian, Daofeng; Wang, Junmin; Cai, Qiang; Chen, Qizuan; Mao, Shanping; Chen, Qianxue; Chang, Jiang

2015-01-01

Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis. PMID:26108681

Genesis and Dissemination of Highly Pathogenic H5N6 Avian Influenza Viruses

PubMed Central

Yang, Lei; Zhu, Wenfei; Li, Xiaodan; Bo, Hong; Zhang, Ye; Zou, Shumei; Gao, Rongbao; Dong, Jie; Zhao, Xiang; Chen, Wenbing; Dong, Libo; Zou, Xiaohui; Xing, Yongcai

2016-01-01

ABSTRACT Clade 2.3.4.4 highly pathogenic avian influenza viruses (H5Nx) have spread from Asia to other parts of the world. Since 2014, human infections with clade 2.3.4.4 highly pathogenic avian influenza H5N6 viruses have been continuously reported in China. To investigate the genesis of the virus, we analyzed 123 H5 or N6 environmental viruses sampled from live-poultry markets or farms from 2012 to 2015 in Mainland China. Our results indicated that clade 2.3.4.4 H5N2/N6/N8 viruses shared the same hemagglutinin gene as originated in early 2009. From 2012 to 2015, the genesis of highly pathogenic avian influenza H5N6 viruses occurred via two independent pathways. Three major reassortant H5N6 viruses (reassortants A, B, and C) were generated. Internal genes of reassortant A and B viruses and reassortant C viruses derived from clade 2.3.2.1c H5N1 and H9N2 viruses, respectively. Many mammalian adaption mutations and antigenic variations were detected among the three reassortant viruses. Considering their wide circulation and dynamic reassortment in poultry, we highly recommend close monitoring of the viruses in poultry and humans. IMPORTANCE Since 2014, clade 2.3.4.4 highly pathogenic avian influenza (H5Nx) viruses have caused many outbreaks in both wild and domestic birds globally. Severe human cases with novel H5N6 viruses in this group were also reported in China in 2014 and 2015. To investigate the genesis of the genetic diversity of these H5N6 viruses, we sequenced 123 H5 or N6 environmental viruses sampled from 2012 to 2015 in China. Sequence analysis indicated that three major reassortants of these H5N6 viruses had been generated by two independent evolutionary pathways. The H5N6 reassortant viruses had been detected in most provinces of southern China and neighboring countries. Considering the mammalian adaption mutations and antigenic variation detected, the spread of these viruses should be monitored carefully due to their pandemic potential. PMID:28003485

Heavy noble gases in solar wind delivered by Genesis mission.

PubMed

Meshik, Alex; Hohenberg, Charles; Pravdivtseva, Olga; Burnett, Donald

2014-02-15

One of the major goals of the Genesis Mission was to refine our knowledge of the isotopic composition of the heavy noble gases in solar wind and, by inference, the Sun, which represents the initial composition of the solar system. This has now been achieved with permil precision: 36 Ar/ 38 Ar = 5.5005 ± 0.0040, 86 Kr/ 84 Kr = .3012 ± .0004, 83 Kr/ 84 Kr = .2034 ± .0002, 82 Kr/ 84 Kr = .2054 ± .0002, 80 Kr/ 84 Kr = .0412 ± .0002, 78 Kr/ 84 Kr = .00642 ± .00005, 136 Xe/ 132 Xe = .3001 ± .0006, 134 Xe/ 132 Xe = .3691 ± .0007, 131 Xe/ 132 Xe = .8256 ± .0012, 130 Xe/ 132 Xe = .1650 ± .0004, 129 Xe/ 132 Xe = 1.0405 ± .0010, 128 Xe/ 132 Xe = .0842 ± .0003, 126 Xe/ 132 Xe = .00416 ± .00009, and 124 Xe/ 132 Xe = .00491 ± .00007 (error-weighted averages of all published data). The Kr and Xe ratios measured in the Genesis solar wind collectors generally agree with the less precise values obtained from lunar soils and breccias, which have accumulated solar wind over hundreds of millions of years, suggesting little if any temporal variability of the isotopic composition of solar wind krypton and xenon. The higher precision for the initial composition of the heavy noble gases in the solar system allows (1) to confirm that, exept 136 Xe and 134 Xe, the mathematically derived U-Xe is equivalent to Solar Wind Xe and (2) to provide an opportunity for better understanding the relationship between the starting composition and Xe-Q (and Q-Kr), the dominant current "planetary" component, and its host, the mysterious phase-Q.

Heavy noble gases in solar wind delivered by Genesis mission

PubMed Central

Meshik, Alex; Hohenberg, Charles; Pravdivtseva, Olga; Burnett, Donald

2017-01-01

One of the major goals of the Genesis Mission was to refine our knowledge of the isotopic composition of the heavy noble gases in solar wind and, by inference, the Sun, which represents the initial composition of the solar system. This has now been achieved with permil precision: 36Ar/38Ar = 5.5005 ± 0.0040, 86Kr/84Kr = .3012 ± .0004, 83Kr/84Kr = .2034 ± .0002, 82Kr/84Kr = .2054 ± .0002, 80Kr/84Kr = .0412 ± .0002, 78Kr/84Kr = .00642 ± .00005, 136Xe/132Xe = .3001 ± .0006, 134Xe/132Xe = .3691 ± .0007, 131Xe/132Xe = .8256 ± .0012, 130Xe/132Xe = .1650 ± .0004, 129Xe/132Xe = 1.0405 ± .0010, 128Xe/132Xe = .0842 ± .0003, 126Xe/132Xe = .00416 ± .00009, and 124Xe/132Xe = .00491 ± .00007 (error-weighted averages of all published data). The Kr and Xe ratios measured in the Genesis solar wind collectors generally agree with the less precise values obtained from lunar soils and breccias, which have accumulated solar wind over hundreds of millions of years, suggesting little if any temporal variability of the isotopic composition of solar wind krypton and xenon. The higher precision for the initial composition of the heavy noble gases in the solar system allows (1) to confirm that, exept 136Xe and 134Xe, the mathematically derived U–Xe is equivalent to Solar Wind Xe and (2) to provide an opportunity for better understanding the relationship between the starting composition and Xe-Q (and Q-Kr), the dominant current “planetary” component, and its host, the mysterious phase-Q. PMID:29151613

Detecting Tsunami Genesis and Scales Directly from Coastal GPS Stations

NASA Astrophysics Data System (ADS)

Song, Y. Tony

2013-04-01

Different from the conventional approach to tsunami warnings that rely on earthquake magnitude estimates, we have found that coastal GPS stations are able to detect continental slope displacements of faulting due to big earthquakes, and that the detected seafloor displacements are able to determine tsunami source energy and scales instantaneously. This method has successfully replicated several historical tsunamis caused by the 2004 Sumatra earthquake, the 2005 Nias earthquake, the 2010 Chilean earthquake, and the 2011 Tohoku-Oki earthquake, respectively, and has been compared favorably with the conventional seismic solutions that usually take hours or days to get through inverting seismographs (reference listed). Because many coastal GPS stations are already in operation for measuring ground motions in real time as often as once every few seconds, this study suggests a practical way of identifying tsunamigenic earthquakes for early warnings and reducing false alarms. Reference Song, Y. T., 2007: Detecting tsunami genesis and scales directly from coastal GPS stations, Geophys. Res. Lett., 34, L19602, doi:10.1029/2007GL031681. Song, Y. T., L.-L. Fu, V. Zlotnicki, C. Ji, V. Hjorleifsdottir, C.K. Shum, and Y. Yi, 2008: The role of horizontal impulses of the faulting continental slope in generating the 26 December 2004 Tsunami, Ocean Modelling, doi:10.1016/j.ocemod.2007.10.007. Song, Y. T. and S.C. Han, 2011: Satellite observations defying the long-held tsunami genesis theory, D.L. Tang (ed.), Remote Sensing of the Changing Oceans, DOI 10.1007/978-3-642-16541-2, Springer-Verlag Berlin Heidelberg. Song, Y. T., I. Fukumori, C. K. Shum, and Y. Yi, 2012: Merging tsunamis of the 2011 Tohoku-Oki earthquake detected over the open ocean, Geophys. Res. Lett., doi:10.1029/2011GL050767 (Nature Highlights, March 8, 2012).

Abyssal and hydrated mantle wedge serpentinised peridotites: a comparison of the 15°20'N fracture zone and New Caledonia serpentinites

NASA Astrophysics Data System (ADS)

Mothersole, Fiona Elizabeth; Evans, Katy; Frost, B. Ronald

2017-08-01

Subduction of serpentinised mantle transfers oxidised and hydrated mantle lithosphere into the Earth, with consequences for the oxidation state of sub-arc mantle and the genesis of arc-related ore deposits. The role of subducted serpentinised mantle lithosphere in earth system processes is uncertain because subduction fluxes are poorly constrained. Most subducted serpentinised mantle is serpentinised on the ocean floor settings. Yet this material is poorly represented in the literature because it is difficult to access. Large volumes of accessible serpentinite are available in ophiolite complexes, and most interpretations of subduction fluxes associated with ultramafic rocks are based on ophiolite studies. Seafloor and ophiolite serpentinisation can occur under different conditions, so it is necessary to assess if ophiolite serpentinites are a good proxy for seafloor serpentinites. Serpentinites sampled during ODP cruise 209 were compared with serpentinites from New Caledonia. The ODP209 serpentinites were serpentinised by modified seawater in a shallow hydrothermal seafloor setting. The New Caledonia serpentinites were serpentinised in a mantle wedge setting by slab-derived fluids, with possible contributions from oceanic serpentinisation and post-obduction serpentinisation. Petrological, whole rock and mineralogical analyses were combined to compare the two sample sets. Petrologically, the evolution of serpentinisation was close to identical in the two environments. However, more oxidised iron, Cl, S and C is present in serpentine from the ODP209 serpentinites relative to the New Caledonia serpentinites. Given these observations, the use of serpentinites from different geodynamic settings as a proxy for abyssal serpentinites from spreading settings must be undertaken with caution.

Petrologic and isotopic data from the Cretaceous (Campanian) Blackhawk Formation and Star Point Sandstone (Mesaverde Group), Wasatch Plateau, Utah

USGS Publications Warehouse

Fishman, Neil S.; Turner, Christine E.; Peterson, Fred

2013-01-01

The presence of discrete minerals associated with coal—whether (1) detrital or authigenic constituents of the coals or in thin mudstone or siltstone units interbedded with coals, or (2) authigenic phases that formed along cleats—might influence its utilization as an energy resource. The build-up of sintered ash deposits on the surfaces of heat exchangers in coal-fired power plants, due to the alteration of minerals during combustion of the coal, can seriously affect the functioning of the boiler and enhance corrosion of combustion equipment. In particular, the presence of sodium in coals has been considered a key factor in the fouling of boilers; however, other elements (such as calcium or magnesium) and the amount of discrete minerals burned with coal can also play a significant role in the inefficiency of and damage to boilers. Previous studies of the quality of coals in the Cretaceous (Campanian) Blackhawk Formation of the Wasatch Plateau, Utah, revealed that the sodium content of the coals varied across the region. To better understand the origin and distribution of sodium in these coals, petrologic studies were undertaken within a sedimentological framework to evaluate the timing and geochemical constraints on the emplacement of sodium-bearing minerals, particularly analcime, which previously had been identified in coals in the Blackhawk Formation. Further, the study was broadened to include not just coals in the Blackhawk Formation from various localities across the Wasatch Plateau, but also sandstones interbedded with the coals as well as sandstones in the underlying Star Point Sandstone. The alteration history of the sandstones in both formations was considered a key component of this study because it records the nature and timing of fluids passing through them and the associated precipitation of sodium-bearing minerals; thus, the alteration history could place constraints on the distribution and timing of sodium mineralization in the interbedded or

Lunar Science Conference, 4th, Houston, Tex., March 5-8, 1973, Proceedings. Volume 1 - Mineralogy and petrology. Volume 2 - Chemical and isotope analyses. Organic chemistry. Volume 3 - Physical properties

NASA Technical Reports Server (NTRS)

Gose, W. A.

1973-01-01

The mineralogy, petrology, chemistry, isotopic composition, and physical properties of lunar materials are described in papers detailing methods, results, and implications of research on samples returned from eight lunar landing sites: Apollo 11, 12, 14, 15, 16, 17, and Luna 16 and 20. The results of experiments conducted or set up on the lunar surface by the astronauts are also described along with observations taken from Command Modules and subsatellites. Major topics include general geology, soil and breccia studies, petrologic studies, mineralogic analyses, elemental compositions, radiometric age determinations, rare gas chemistry, radionuclides, organogenic compounds, particle track records, thermal properties, seismic studies, resonance studies, orbital mapping, lunar atmosphere, magnetic studies, electrical studies, optical properties, and microcratering. Individual items are announced in this issue.

On gravitational chirality as the genesis of astrophysical jets

NASA Astrophysics Data System (ADS)

Tucker, R. W.; Walton, T. J.

2017-02-01

It has been suggested that single and double jets observed emanating from certain astrophysical objects may have a purely gravitational origin. We discuss new classes of plane-fronted and pulsed gravitational wave solutions to the equation for perturbations of Ricci-flat spacetimes around Minkowski metrics, as models for the genesis of such phenomena. These solutions are classified in terms of their chirality and generate a family of non-stationary spacetime metrics. Particular members of these families are used as backgrounds in analysing time-like solutions to the geodesic equation for test particles. They are found numerically to exhibit both single and double jet-like features with dimensionless aspect ratios suggesting that it may be profitable to include such backgrounds in simulations of astrophysical jet dynamics from rotating accretion discs involving electromagnetic fields.

A theory of the genesis of breast duct papilloma.

PubMed

WHANG, J

1960-03-01

While it is not the intent to argue that papilloma never develops in the conventionally accepted manner (proliferative growth from the wall of a pre-existing cavity) a new, perhaps alternative, genesis is suggested. The concept is that, beginning with the usual lobular structure of the breast, first by hyperplasia and then by coalescence of alveoli, seen earliest at the periphery of the lobule, spaces appear between the content of the lobule and the wall. By confluence of these spaces a larger cystic cavity is formed. Coalescence of alveoli through the body of the central mass, in the same way as at the periphery, develops the familiar pattern of "papilloma." Following the earlier hyperplasia, regressive changes appear and may go on to complete disintegration of the papillary mass, leaving a smooth-walled cavity.

The Flare Genesis Experiment

NASA Technical Reports Server (NTRS)

Rust, D. M.

2002-01-01

Using the Flare Genesis Experiment (FGE), a balloon-borne observatory with an 80-cm solar telescope we observed the active region NOAA 8844 on January 25, 2000 for several hours. FGE was equipped with a vector polarimeter and a tunable Fabry-Perot narrow-band filter. It recorded time series of filtergrams, vector magnetograms, and Dopplergrams at the Ca(I) 6122.2 angstrom line, and H-alpha filtergrams with a cadence between 2.5 and 7.5 minutes. At the time of the observations, NOAA 8844 was located at approximately 5 N 30 W. The region was rapidly growing during the observations; new magnetic flux was constantly emerging in three supergranules near its center. We describe in detail how the FGE data were analyzed and report on the structure and behavior of peculiar moving dipolar features (MDFs) observed in the active region. In longitudinal magnetograms, the MDFs appeared to be small dipoles in the emerging fields. The east-west orientation of their polarities was opposite that of the sunspots. The dipoles were oriented parallel to their direction of motion, which was in most cases towards the sunspots. Previously, dipolar moving magnetic features have only been observed flowing out from sunspots. Vector magnetograms show that the magnetic field of each MDF negative part was less inclined to the local horizontal than the ones of the positive part. We identify the MDFs as undulations, or stitches, where the emerging flux ropes are still tied to the photosphere. We present a U-loop model that can account for their unusual structure and behavior, and it shows how emerging flux can shed its entrained mass.

Development of Chemical and Mechanical Cleaning Procedures for Genesis Solar Wind Samples

NASA Technical Reports Server (NTRS)

Schmeling, M.; Jurewicz, A. J. G.; Gonzalez, C.; Allums, K. K.; Allton, J. H.

2018-01-01

The Genesis mission was the only mission returning pristine solar material to Earth since the Apollo program. Unfortunately, the return of the spacecraft on September 8, 2004 resulted in a crash landing shattering the solar wind collectors into smaller fragments and exposing them to desert soil and other debris. Thorough surface cleaning is required for almost all fragments to allow for subsequent analysis of solar wind material embedded within. However, each collector fragment calls for an individual cleaning approach, as contamination not only varies by collector material but also by sample itself.

Petrological, Magnetic and Geochemical Characterization of Cretaceous-Paleogene Boundary El Mimbral and La Lajilla Sections, Northeastern Mexico

NASA Astrophysics Data System (ADS)

Ortega Nieto, A.; Fucugauchi, J. U.; Perez-Cruz, L. L.

2009-12-01

We present initial results of a petrological, magnetic and geochemical study of El Mimbral and La Lajilla sections that span the Cretaceous-Paleogene (K-Pg) boundary. K-Pg sections in northeastern Mexico have been intensively studied in past years, mainly because of their relationship to the Chicxulub crater in the Yucatan platform and for investigating the nature, origin, stratigraphic relations and age of the impact ejecta deposits. The K-Pg boundary is preserved in between hemipelagic marls and limestones of the Mendez (Maastrichtian) and Velasco (Paleocene) formations. The two sections are situated about 1000 km away from Chicxulub and K-Pg deposits are part of the proximal ejecta and the complex channelized siliciclastic units. We had separated the siliciclastic units into two parts, with a basal coarse poorly graded spherulitic bed some 0.2 to 1 m thick and a second part with several sandstone siltstone beds that have been grouped in various ways in previous studies. In the field, samples were collected across stratigraphic profiles for rock magnetic, petrological and geochemical analyses. Using field observations and analytical data, detailed columns for the two localities are prepared. Rock magnetic measurements include susceptibility, remanent and isothermal magnetization and remanent coercivity. Magnetic hysteresis loops and IRM and back-field demagnetization were measured for samples of spherulitic bed. X-ray fluorescence analyses on whole rock were complemented with previous data obtained for the Mimbral section by atomic absorption spectrometry and inductively coupled plasma mass spectrometry (including platinum group elements). Further detailed analysis concentrated in the ejecta material. The spherulitic bed is characterized by Fe-Mg rich chlorite and Si-Al-K rich glass spherules and carbonate accretionary lapilli spherules. The silicic component spherules are altered to calcite or chlorite-smectite, with some retaining glass cores. Spherules have

JPL Genesis and Rapid Intensification Processes (GRIP) Portal

NASA Technical Reports Server (NTRS)

Knosp, Brian W.; Li, P. Peggy; Vu, Quoc A.; Turk, Francis J.; Shen, Tsae-Pyng J.; Hristova-Veleva, Svetla M.; Licata, Stephen J.; Poulsen, William L.

2012-01-01

Satellite observations can play a very important role in airborne field campaigns, since they provide a comprehensive description of the environment that is essential for the experiment design, flight planning, and post-experiment scientific data analysis. In the past, it has been difficult to fully utilize data from multiple NASA satellites due to the large data volume, the complexity of accessing NASA s data in near-real-time (NRT), as well as the lack of software tools to interact with multi-sensor information. The JPL GRIP Portal is a Web portal that serves a comprehensive set of NRT observation data sets from NASA and NOAA satellites describing the atmospheric and oceanic environments related to the genesis and intensification of the tropical storms in the North Atlantic Ocean. Together with the model forecast data from four major global atmospheric models, this portal provides a useful tool for the scientists and forecasters in planning and monitoring the NASA GRIP field campaign during the 2010 Atlantic Ocean hurricane season. This portal uses the Google Earth plug-in to visualize various types of data sets, such as 2D maps, wind vectors, streamlines, 3D data sets presented at series of vertical cross-sections or pointwise vertical profiles, and hurricane best tracks and forecast tracks. Additionally, it allows users to overlap multiple data sets, change the opacity of each image layer, generate animations on the fly with selected data sets, and compare the observation data with the model forecast using two independent calendars. The portal also provides the capability to identify the geographic location of any point of interest. In addition to supporting the airborne mission planning, the NRT data and portal will serve as a very rich source of information during the post-field campaign analysis stage of the airborne experiment. By including a diverse set of satellite observations and model forecasts, it provides a good spatial and temporal context for the

Petrology and geochemistry of lithic fragments separated from the Apollo 15 deep-drill core

NASA Technical Reports Server (NTRS)

Lindstrom, M. M.; Nielsen, R. L.; Drake, M. J.

1977-01-01

Petrological and geochemical analysis of lithic fragments separated from the Apollo 15 deep-drill core showed these fragments to fall into the essentially the same range of rock types as observed in surface soil samples and large rock samples. Three particles are singled out as being of special interest. One sample is a mare basalt containing extremely evolved phases. The particle may represent small-scale imperfect crystal/liquid separation in a lava flow. A green glass particle is not the ultramafic emerald green glass described from the Apollo 15 site, but rather an ANT-like light green color, and has a quite different chemical composition from the ultramafic variety. One mare basalt displays a positive Eu anomaly and is enriched in plagioclase relative to olivine plus pyroxene.

Assortative sociality, limited dispersal, infectious disease and the genesis of the global pattern of religion diversity

PubMed Central

Fincher, Corey L; Thornhill, Randy

2008-01-01

Why are religions far more numerous in the tropics compared with the temperate areas? We propose, as an answer, that more religions have emerged and are maintained in the tropics because, through localized coevolutionary races with hosts, infectious diseases select for three anticontagion behaviours: in-group assortative sociality; out-group avoidance; and limited dispersal. These behaviours, in turn, create intergroup boundaries that effectively fractionate, isolate and diversify an original culture leading to the genesis of two or more groups from one. Religion is one aspect of a group's culture that undergoes this process. If this argument is correct then, across the globe, religion diversity should correlate positively with infectious disease diversity, reflecting an evolutionary history of antagonistic coevolution between parasites and hosts and subsequent religion genesis. We present evidence that supports this model: for a global sample of traditional societies, societal range size is reduced in areas with more pathogens compared with areas with few pathogens, and in contemporary countries religion diversity is positively related to two measures of parasite stress. PMID:18664438

Complexity as AN Epistemic Revolution: Considerations on the New Science in the Context of Western Intellectual History

NASA Astrophysics Data System (ADS)

Popolo, Damian

The paper will seek to present a genesis of complexity in European philosophical thought. Following the works of Gleick and Hobsbawn it is possible to discern the emergence of complexity's ethos in the `age of revolutions'. Gleick, for example, has noted the influence of natural philosophy on the first precursors of chaos theory. Natural philosophy itself was deeply anchored in German romanticism. The paper will thus seek to present, following Foucault, an `Archaeology of Complexity' which considers Foucault's definition of epistemes as evolving modes of thought. In particular, the paper will seek to use Foucault's description of the modern episteme in order to detect the novelty inherent within the ethos of Complexity.

LCSs in tropical cyclone genesis

NASA Astrophysics Data System (ADS)

Rutherford, B.; Montgomery, M. T.

2011-12-01

The formation of tropical cyclones in the Atlantic most often occurs at the intersection of the wave trough axis of a westward propagating African easterly wave and the wave critical latitude. Viewed in a moving reference frame with the wave, a cat's eye region of cyclonic recirculation can be seen in streamlines prior to genesis. The cat's eye recirculation region has little strain deformation and its center serves as the focal point for aggregation of convectively generated vertical vorticity. Air inside the cat's eye is repeatedly moistened by convection and is protected from the lateral intrusion of dry air. Since the flow is inherently time-dependent, we contrast the time-dependent structures with Eulerian structures of the wave-relative frame. Time-dependence complicates the kinematic structure of the recirculation region as air masses from the outer environment are allowed to interact with the interior of the cat's eye. LCSs show different boundaries of the cat's eye than the streamlines in the wave-relative frame. These LCSs are particularly important for showing the pathways of air masses that interact with the developing vortex, as moist air promotes development by supporting deep convection, while interaction with dry air impedes development. We primarily use FTLEs to locate the LCSs, and show the role of LCSs in both developing and non-developing storms. In addition, we discuss how the vertical coherence of LCSs is important for resisting the effects of vertical wind shear.

Petrologic evolution of CM chondrites: The difficulty of discriminating between nebular and parent-body effects

NASA Astrophysics Data System (ADS)

Kerridge, J. F.; McSween, H. Y., Jr.; Bunch, T. E.

1994-07-01

We wish to draw attention to a major controversy that has arisen in the area of CM-chondrite petrology. The problem is important because its resolution will have profound implications for ideas concerning nebular dynamics, gas-solid interactions in the nebula, and accretionary processes in the nebula, among other issues. On the one hand, cogent arguments have been presented that 'accretionary dust mantles,' were formed in the solar nebula prior to accretion of the CM parent asteroid(s). On the other hand, no-less-powerful arguments have been advanced that a significant fraction of the CM lithology is secondary, produced by aqueous alteration in the near-surface regions of an asteroid-sized object. Because most, if not all, CM chondrites are breccias, these two views could coexist harmoniously, were it not for the fact that some of the coarse-grained lithologies surrounded by 'accretion dust mantles' are themselves of apparently secondary origin. Such an observation must clearly force a reassessment of one or both of the present schools of thought. Our objective here is to stimulate such a reassessment. Four possible resolutions of this conflict may be postulated. First, perhaps nature found a way of permitting such secondary alteration to take place in the nebula. Second, maybe dust mantles could form in a regolith, rather than a nebular, environment. Third, it is possible that dust mantles around secondary lithologies are different from those around primary lithologies. Finally, perhaps formation of CM chondrites involved a more complex sequence of events than visualized so far, so that some apparently 'primary' processes postdated certain 'secondary' processes.

Emerging Concepts About Prenatal Genesis, Aberrant Metabolism and Treatment Paradigms in Polycystic Ovary Syndrome

PubMed Central

Witchel, Selma F; Recabarren, Sergio E; Gonzalez, Frank; Diamanti-Kandarakis, Evanthia; Cheang, Kai I; Duleba, Antoni J; Legro, Richard S; Homburg, Roy; Pasquali, Renato; Lobo, Rogerio; Zouboulis, Christos C.; Kelestimur, Fahrettin; Fruzzetti, Franca; Futterweit, Walter; Norman, Robert J; Abbott, David H

2012-01-01

The interactive nature of the 8th Annual Meeting of the Androgen Excess & PCOS Society Annual Meeting in Munich, Germany (AEPCOS 2010) and subsequent exchanges between speakers led to emerging concepts in PCOS regarding its genesis, metabolic dysfunction, and clinical treatment of inflammation, metabolic dysfunction, anovulation and hirsutism. Transition of care in congenital adrenal hyperplasia from pediatric to adult providers emerged as a potential model for care transition involving PCOS adolescents. PMID:22661293

3D Integrated geophysical-petrological modelling of the Iranian lithosphere

NASA Astrophysics Data System (ADS)

Mousavi, Naeim; Ardestani, Vahid E.; Ebbing, Jörg; Fullea, Javier

2016-04-01

The present-day Iranian Plateau is the result of complex tectonic processes associated with the Arabia-Eurasia Plate convergence at a lithospheric scale. In spite of previous mostly 2D geophysical studies, fundamental questions regarding the deep lithospheric and sub-lithospheric structure beneath Iran remain open. A robust 3D model of the thermochemical lithospheric structure in Iran is an important step toward a better understanding of the geological history and tectonic events in the area. Here, we apply a combined geophysical-petrological methodology (LitMod3D) to investigate the present-day thermal and compositional structure in the crust and upper mantle beneath the Arabia-Eurasia collision zone using a comprehensive variety of constraining data: elevation, surface heat flow, gravity potential fields, satellite gravity gradients, xenoliths and seismic tomography. Different mantle compositions were tested in our model based on local xenolith samples and global data base averages for different tectonothermal ages. A uniform mantle composition fails to explain the observed gravity field, gravity gradients and surface topography. A tectonically regionalized lithospheric mantle compositional model is able to explain all data sets including seismic tomography models. Our preliminary thermochemical lithospheric study constrains the depth to Moho discontinuity and intra crustal geometries including depth to sediments. We also determine the depth to Curie isotherm which is known as the base of magnetized crustal/uppermost mantle bodies. Discrepancies with respect to previous studies include mantle composition and the geometry of Moho and Lithosphere-Asthenosphere Boundary (LAB). Synthetic seismic Vs and Vp velocities match existing seismic tomography models in the area. In this study, depleted mantle compositions are modelled beneath cold and thick lithosphere in Arabian and Turan platforms. A more fertile mantle composition is found in collision zones. Based on our 3

The petrology and geochemistry of a metabasite belt along the southern margin of Alaska

PubMed Central

Bruand, E.; Gasser, D.; Bonnand, P.; Stuewe, K.

2011-01-01

A 600 km long metabasite belt is exposed at the southern border of the Chugach terrane in southern Alaska, south of the Eocene Chugach Metamorphic Complex (CMC). In this contribution, we present petrologic and geochemical results for parts of this metabasite belt. The metabasites studied are amphibolite grade and their PT conditions are evaluated with hornblende–plagioclase thermometry and the average PT method. From west to east the peak metamorphic conditions calculated are: about 730–793 °C for pressures between 5 and 15 kbar in the westernmost part, about 740–760 °C and 5 kbar in the middle locality and about 640–675 °C and 8 kbar in the easternmost locality. These results are comparable with the metamorphic conditions obtained on metapelite of the CMC for the westernmost and easternmost localities. In contrast, in the central part of the CMC, the metabasites experienced probably lower pressures than the metapelites to the north. Rare earth and trace element patterns of the metabasite belt are comparable with typical altered basalt patterns and reveal MORB and arc-tholeiitic geochemical characteristics. The presence of Ba and U anomalies are interpreted as a result of alteration prior to subduction, the Pb anomaly as a result of an intra-oceanic island arc signature and the Sr anomaly as a result of the interaction of sediments with the metabasites during subduction. We suggest that the association of MORB and arc tholeiitic rocks in the metabasite belt is likely derived from an intra-oceanic island arc which accreted to the Alaskan margin. PMID:26523072

Petrology of Ortsog-Uul peridotite-gabbro massif in Western Mongolia

NASA Astrophysics Data System (ADS)

Shapovalova, M.; Tolstykh, N.; Shelepaev, R.; Cherdantseva, M.

2017-12-01

The Ortsog-Uul mafic-ultramafic massif of Western Mongolia is located in a tectonic block with overturned bedding. The massif hosts two intrusions: a rhythmically-layered peridotite-gabbro association (Intrusion 1) and massive Bt-bearing amphibole-olivine gabbro (Intrusion 2). Intrusions 1 and 2 have different petrology features. Early Intrusion 1 (278±2.5Ma) is characterized by lower concentrations of alkalis, titanium and phosphorus than late Intrusion 2 (272±2Ma). The chondrite-normalized REE and primitive mantle-normalized rare elements patterns of Ortsog-Uul intrusions have similar curves of elements distribution. However, Intrusion 2 is characterized higher contents of REE and rare elements. High concentrations of incompatible elements are indicative of strong fractionation process. It has been suggested that Intrusions 1 and 2 derived from compositionally different parental melts. Model calculations (COMAGMAT-3.57) show that parental melts of two intrusions were close to high-Mg picrobasaltic magmas. The concentration of MgO in melt is 16.21 (Intrusion 1) and 16.17 (Intrusion 2). Isotopic data of Ortsog-Uul magmatic rocks exhibit different values of εNd (positive and negative) for Intrusion 1 and 2, respectively.

Petrology of Zircon-Bearing Diogenite Northwest Africa 10666

NASA Technical Reports Server (NTRS)

Tanner, T. B.; Jeffcoat, C. R.; Righter, M.; Berger, E. L.; Lapen, T. J.; Irving, A. J.; Kuehner, S. M.; Fujihara, G.

2017-01-01

The howardite, eucrite, and diogenite (HED) meteorites are a group of achondrites thought to be derived from the asteroid 4 Vesta, though there is active debate as to whether all diogenites are part of the HED suite. Petrologic investigation of the HED meteorite group provides a means of understanding early planetary differentiation processes and early evolution of planets in our solar system. Diogenites are predominantly coarse grained ortho-pyroxenites with some samples containing appreciable amounts of clinopyroxene, olivine, chromite, and plagioclase. Accessory metal, troilite, and apatite are common. Many diogenites are brecciated, however, there are few poorly to unbrecciated samples. Diogenites are important because they may represent the lower crust of 4 Vesta. Although Mg isotope data indicates that the sources of diogenites are ancient, their crystallization ages are difficult to constrain due to their protracted thermal histories. The limited chronologic data for diogenites also limits the ability to test petrogenetic connections with eucrites and even parent body. A reliable and high closure-temperature isotope system, such as U-Pb in zircon, is needed to address the timing of diogenite igneous crystallization. Description of the textures and mineralogy of diogenites are essential to their classification and understanding their formation, in particular, whether all phases are petrogenetically related. Here, we present detailed petrographic data from a rare zircon-bearing feldspathic diogenite, Northwest Africa (NWA) 10666 and provide textural evidence for igneous crystallization of the zircon.

Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity.

PubMed

Liu, Baohui; Lin, Xi; Yang, Xiangsheng; Dong, Huimin; Yue, Xiaojing; Andrade, Kelsey C; Guo, Zhentao; Yang, Jian; Wu, Liquan; Zhu, Xiaonan; Zhang, Shenqi; Tian, Daofeng; Wang, Junmin; Cai, Qiang; Chen, Qizuan; Mao, Shanping; Chen, Qianxue; Chang, Jiang

2015-09-01

Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Genesis of Atlantic Lows Experiment NASA Electra Boundary Layer Flights Data Report

NASA Technical Reports Server (NTRS)

Palm, Stephen P.; Melfi, S. H.; Boers, Reinout

1988-01-01

The objective of this research was to obtain high resolution measurements of the height of the Marine Atmospheric Boundary Layer (MABL) during cold air outbreaks using an Airborne Lidar System. The research was coordinated with other investigators participating in the Genesis of Atlantic Lows Experiment (GALE). An objective computerized scheme was developed to obtain the Boundary Layer Height from the Lidar Data. The algorithm was used on each of the four flight days producing a high resolution data set of the MABL height over the GALE experiment area. Plots of the retrieved MABL height as well as tabular data summaries are presented.

Petrology of Amoeboid Olivine Aggregates in Antarctic CR Chondrites: Comparison With Other Carbonaceous Chondrites

NASA Technical Reports Server (NTRS)

Komatsu, M.; Fagan, T. J.; Yamaguchi, A.; Mikouchi, T.; Zolensky, M. E.; Yasutake, M.

2016-01-01

Amoeboid olivine aggregates (AOAs) are important refractory components of carbonaceous chondrites and have been interpreted to represent solar nebular condensates that experienced high-temperature annealing, but largely escaped melting. In addition, because AOAs in primitive chondrites are composed of fine-grained minerals (forsterite, anorthite, spinel) that are easily modified during post crystallization alteration, the mineralogy of AOAs can be used as a sensitive indicator of metamorphic or alteration processes. AOAs in CR chondrites are particularly important because they show little evidence for secondary alteration. In addition, some CR AOAs contain Mn-enriched forsterite (aka low-iron, Mn-enriched or LIME olivine), which is an indicator of nebular formation conditions. Here we report preliminary results of the mineralogy and petrology of AOAs in Antarctic CR chondrites, and compare them to those in other carbonaceous chondrites.

Complex pegmatite - apelitic of Cabecinha - strategies appreciation of geological heritage and economic development of the region

NASA Astrophysics Data System (ADS)

Nobre, José; Cabral, Tiago; Cabral, João; Gomes, Ana

2014-05-01

The Complex pegmatite - apelitic of Cabecinha corresponds to an isolated ridge that reaches 933 meters, located in the middle zone of transition between the Hesperian massif and the Cova da Beira being located in the NE central part of Portugal, more specifically in the Mountainous region of the province of Beira Alta, council of Sabugal. This complex lies embedded in porphyritic granites with terms of switching to a medium-grained granite rich in sodium feldspars in which they are muscovite granite intrusions. The lodes have pegmatites with NE-SW orientation, presenting phases of predominantly quartz crystallization with multiple parageneses. The inclusions observed are veins filonianian secondary. Some veins have structural discontinuity due to further their training tectonics. The apelitico material is basic in nature engaging in descontinuiddes of pegmatite material, showing no preferred orientation. The petrological characteristics of the area in question provide the appearance of motivating exotic landforms of scientific interest. These landforms, over time, have motivated the popular level the emergence of various myths, thus contributing to the enrichment of the local cultural heritage. This study proceeded to the geological and geomorphological mapping an area of about 6945,350 m2 with a maximum length of 182 m. The huge patent mineralogical, petrological and geomorphological level geodiversity, allied to the structural complexity and associated cultural heritage, allow geoconservation strategies and recovery, using new multimedia technologies including use of QR codes and 3D. All this geological framework and environment becomes an asset for the scientific, educational and economic development of the region. On the other hand, it has the vital Importance in the context of the strategy of forming a geological park, in the point of view of tourism, research and interpretation.

[Spatial organization of bioelectrical brain activity in epilepsy and amenorrhea of central genesis].

PubMed

Avakian, G N; Oleĭnikova, O M; Nerobkova, L N; Dovletkhanova, E R; Mitrofanov, A A; Gusev, E I

2002-01-01

The study aimed at modification of co-herent analysis (CA), as a mathematical method for EEG data processing for objective evaluation of bioelectric brain activity spatial organization in women with epilepsy and secondary amenorrhea of central genesis. One hundred sixty one women (30 with epilepsy, 116 with amenorrhea and 115 controls aged 15 to 41 years) have been examined. Characteristic changes of cortico-cortical inter- and intra-hemisphere relations for patients with catamenial (CTM) and noncatamenial (NCTM) epilepsy in different menstrual cycle terms were found. The most distinct changes were detected in theta-activity analysis. In the beginning of menstrual cycle, the patients with CTM epilepsy exhibited higher CA indices in theta-rhythm range in all right hemisphere pairs studied. On the contrary, patients with NCTM epilepsy exhibited lower CA indices mainly in the right brain hemisphere. alpha-rhythm spatial organization analysis in the same patients showed similar correlations, but they were better expressed in alpha-rhythm generation zone: in the beginning of menstrual cycle CA indices were high in patients with CTM epilepsy and low in those with NCTM epilepsy. Comparing to controls, patients with secondary amenorrhea of central genesis showed most distinct changes in theta-activity towards the CA indices increase in the majority of the leads. In patients with epilepsy and amenorrhea, CA indices of right brain hemisphere and intra-central temporal lead pairs were lower than in patients with amenorrhea without epilepsy by both alpha- and theta-rhythms.

The connection between crustal reworking and petrological diversity in the deep crust: clues from migmatites

NASA Astrophysics Data System (ADS)

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

2016-04-01

The deep levels of the continental crust have been extensively reworked as result of crustal differentiation. Migmatites are widespread in these high-grade metamorphic terrains, and provide valuable information on how processes such as partial melting, segregation of the melt from the residue and subsequent chemical exchanges lead to the petrological diversity found in the deep crust. This study investigates processes that transformed a largely uniform, metagranodiorite protolith into a very complex migmatite that contains three varieties of diatexites (grey, schlieren and homogenous diatexites) and several types of leucosomes. The Kinawa Migmatite is part of the Archean TTG crust in the São Francisco Craton (Brazil), which has been reworked in a shear zone environment at upper amphibolite facies conditions (<730°C and 5-6 kbar); thus it may be typical of crustal reworking in the interior of old cratons [1]. Grey diatexites are residual rocks formed by the extraction of a water-fluxed melt created via the reaction Pl + Kfs + Qz + H2O = melt. Diversity within the grey diatexites arises from different degrees of melt segregation (maximum ~40% melt). Schlieren diatexites are very heterogeneous rocks in which residuum-rich domains alternate with leucocratic quartzo-feldspathic domains where melt accumulated. Homogeneous diatexites are coarse-grained leucocratic rocks and represent larger bodies of anatectic melt with minor amounts (<20%) of entrained residuum. Leucosomes display a wide range of compositions from tonalitic to alkali-feldspar granite. Leucosomes, homogeneous diatexites and the quartzo-feldspathic domains in the schlieren diatexites all show a sequence of microstructural stages from plagioclase-dominated to K-feldspar-dominated frameworks many of which show evidence for tectonic compaction. Thus, further segregation of melt from solids occurred during crystallization. Minor amphibolite dykes in the metagranodiorite did not melt. They occur as angular to

Additional Sr Isotopic Heterogeneity in Zagami Olivine-Rich Lithology

NASA Technical Reports Server (NTRS)

Misawa, K.; Niihara, T.; Shih, C.-Y; Reese, Y. D.; Nyquist, L. E.; Yoneda, S.; Yamashita, H.

2012-01-01

Prior isotopic analyses of Zagami have established differing initial Sr-87/Sr-86 (ISr) ratios of among Zagami lithologies, fine-grained (FG), coarse-grained (CG), and dark mottled lithologies (DML)]. The Zagami sample (KPM-NLH000057) newly allocated from the Kanagawa Prefectural Museum of Natural History contained DML and the Ol-rich lithology which included more ferroan olivines (Ol-rich: Fa(sub 97- 99) vs late-stage melt pockets: Fa(sub 90-97)]). We have combined mineralogy-petrology and Rb-Sr isotopic studies on the Kanagawa Zagami sample, which will provide additional clues to the genesis of enriched shergottites and to the evolution of Martian crust and mantle

Genesis failure investigation report : JPL Failure Review Board, Avionics Sub-Team

NASA Technical Reports Server (NTRS)

Klein, John; Manning, Rob; Barry, Ed; Donaldson, Jim; Rivellini, Tom; Battel, Steven; Savino, Joe; Lee, Wayne; Dalton, Jerry; Underwood, Mark;

Elemental Redistribution at the Onset of Soil Genesis from Basalt as Measured in a Soil Lysimeter System

NASA Astrophysics Data System (ADS)

Wang, Y.; Umanzor, M.; Alves Meira Neto, A.; Sengupta, A.; Amistadi, M. K.; Root, R.; Troch, P.; Chorover, J.

2017-12-01

Elemental translocation, resulting in enrichment or depletion relative to parent rock, is a consequence of mineral dissolution and precipitation reactions of soil genesis. Accurate measurement of translocation in natural systems is complicated by factors such as parent material heterogeneity and dust deposition. In the present work, a fully controlled and monitored 10° sloping soil lysimeter with known homogeneous initial conditions, was utilized to investigate initial stages of soil genesis from 1 m3 of crushed basalt. Throughout the two-year experiment, periodic irrigation coupled with sensor measurements enabled monitoring of changes in internal moisture states. A total 15-meter water influx resulted in distinct efflux patterns, wetting and drying cycles, as well as high volume water storage. Biological changes, such as algal and grass emergence, were visible on the soil surface, and microbial colonization throughout the profile was measured in a companion study, suggesting that biogeochemical hotspots may have formed. Forensic excavation and sampling of 324 voxels captured the final state heterogeneity of the lysimeter with respect to length and depth. Total elemental concentrations and a five-step sequential extraction (SE) scheme quantified elemental redistributions into operationally-defined pools including exchangeable, poorly-crystalline (hydr)oxides, and crystalline (hydr)oxides. Data were correlated to water flux and storage that was determined from sensor and tracer data over the two years of rock-water interaction; then used to map 2D cross-sections and identify geochemical hotspots. Total and SE Fe concentrations were used to establish a governing mass balance equation, and sub mass balance equations with unique partitioning coefficients of Fe were developed for each SE pool, respectively. The results help to explain elemental (e.g., Fe) lability and redistribution due to physical and geochemical weathering during the initial stages of soil genesis.

Zr-in-rutile resetting in aluminosilicate bearing ultra-high temperature granulites: Refining the record of cooling and hydration in the Napier Complex, Antarctica

NASA Astrophysics Data System (ADS)

Mitchell, Ruairidh J.; Harley, Simon L.

2017-02-01

The relative validity and closure temperature of the Zr-in-rutile thermometer for recording UHT metamorphism are process dependent and hotly debated. We present an integrated petrological approach to Zr-in-rutile thermometry including phase equilibrium (pseudosection) modelling in complex chemical systems with updated mineral a-X models and systematic in-situ microanalysis of rutile. This study is centred on high-pressure rutile bearing UHT granulites from Mt. Charles, Napier Complex, Antarctica. P-T phase equilibrium modelling of two garnet bearing granulites (samples 49677, 49701) constrains an overall post-peak near isobaric cooling (IBC) evolution for the Napier Complex at Mt. Charles; from 14 kbar, 1100 °C with moderate decompression to 11 kbar, 800-900 °C. Local hydration on cooling over this temperature range is recorded in a kyanite bearing granulite (sample 49688) with an inferred injection of aqueous fluid equivalent to up to 9 mol% H2O from T-MH2O modelling. Further late stage cooling to < 740 °C is recorded by voluminous retrograde mica growth and partial preservation of a ky-pl-kfs-bt-liq bearing equilibrium assemblage. Overall, Zr-in-rutile temperatures at 11 kbar (Tomkins et al., 2007) are reset to between 606 °C and 780 °C across all samples, with flat core-rim Zr concentration profiles in all rutiles. However, zircon precipitates as inclusions, needle exsolutions, or rods along rutile grain boundaries are recrystallised from rutiles in qz/fsp domains. Reintegrating the Zr-in-rutile concentration 'lost' via the recrystallisation of these zircon precipitates (e.g. Pape et al., 2016) can recover maximum concentrations of up to 2.2 wt% and thus maximum peak temperatures of 1149 °C at 11 kbar. Rutile Nb-Ta signatures and rounded rutile grains without zircon precipitates in hydrated mica domains in sample 49688 provide evidence for fluid-mediated mobility of Zr and Nb during retrograde cooling in hydrated lithologies. Aqueous fluid supplemented

Cosmogonies and Culture: Teaching Genesis and the Popol Vuh in an Interdisciplinary Course at a Christian University

ERIC Educational Resources Information Center

Parsons, Mikeal C.; Cook, Garrett

2004-01-01

This paper explores the possibilities of teaching Genesis and the Popol Vuh, the Mayan creation account, in an interdisciplinary course at a church-related institution. The course is part of an alternative, interdisciplinary core curriculum typically taken by two hundred students a year at the university. A comparison of the Popol Vuh with Genesis…

Higher Magnification Imaging of the Polished Aluminum Collector Returned from the Genesis Mission

NASA Technical Reports Server (NTRS)

Rodriquez, Melissa C.; Burkett, P. J.; Allton, J. H.

2011-01-01

The polished aluminum collector (previously referred to as the polished aluminum kidney) was intended for noble gas analysis for the Gene-sis mission. The aluminum collector, fabricated from alloy 6061T, was polished for flight with alumina, then diamond paste. Final cleaning was performed by soak-ing and rinsing with hexane, then isopropanol, and last-ly megasonically energized ultrapure water prior to installation. It was mounted inside the collector canister on the thermal shield at JSC in 2000. The polished aluminum collector was not surveyed microscopically prior to flight.

The Genesis Mission Solar Wind Collection: Solar-Wind Statistics over the Period of Collection

NASA Technical Reports Server (NTRS)

Barraclough, B. L.; Wiens, R. C.; Steinberg, J. E.; Reisenfeld, D. B.; Neugebauer, M.; Burnett, D. S.; Gosling, J.; Bremmer, R. R.

2004-01-01

The NASA Genesis spacecraft was launched August 8, 2001 on a mission to collect samples of solar wind for 2 years and return them to earth September 8, 2004. Detailed analyses of the solar wind ions implanted into high-purity collection substrates will be carried out using various mass spectrometry techniques. These analyses are expected to determine key isotopic ratios and elemental abundances in the solar wind, and by extension, in the solar photosphere. Further, the photospheric composition is thought to be representative of the solar nebula with a few exceptions, so that the Genesis mission will provide a baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. The collection of solar wind samples is almost complete. Collection began for most substrates in early December, 2001, and is scheduled to be complete on April 2 of this year. It is critical to understand the solar-wind conditions during the collection phase of the mission. For this reason, plasma ion and electron spectrometers are continuously monitoring the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons. Here we report on the solar-wind conditions as observed by these in-situ instruments during the first half of the collection phase of the mission, from December, 2001 to present.

Origin of the lunar highlands Mg-suite: An integrated petrology, geochemistry, chronology, and remote sensing perspective

DOE PAGES

Shearer, C. K.; Elardo, S. M.; Petro, N. E.; ...

2014-12-23

The Mg-suite represents an enigmatic episode of lunar highlands magmatism that presumably represents the first stage of crustal building following primordial differentiation. This review examines the mineralogy, geochemistry, petrology, chronology, and the planetary-scale distribution of this suite of highlands plutonic rocks, presents models for their origin, examines petrogenetic relationships to other highlands rocks, and explores the link between this style of magmatism and early stages of lunar differentiation. Of the models considered for the origin of the parent magmas for the Mg-suite, the data best fit a process in which hot (solidus temperature at ≥2 GPa = 1600 to 1800more » °C) and less dense (r ~3100 kg/m3) early lunar magma ocean cumulates rise to the base of the crust during cumulate pile overturn. Some decompressional melting would occur, but placing a hot cumulate horizon adjacent to the plagioclase-rich primordial crust and KREEP-rich lithologies (at temperatures of <1300 °C) would result in the hybridization of these divergent primordial lithologies, producing Mg-suite parent magmas. As urKREEP (primeval KREEP) is not the “petrologic driver” of this style of magmatism, outside of the Procellarum KREEP Terrane (PKT), Mg-suite magmas are not required to have a KREEP signature. Evaluation of the chronology of this episode of highlands evolution indicates that Mg-suite magmatism was initiated soon after primordial differentiation (<10 m.y.). Alternatively, the thermal event associated with the mantle overturn may have disrupted the chronometers utilized to date the primordial crust. Petrogenetic relationships between the Mg-suite and other highlands suites (e.g., alkali-suite and magnesian anorthositic granulites) are consistent with both fractional crystallization processes and melting of distinctly different hybrid sources.« less

A THEORY OF THE GENESIS OF BREAST DUCT PAPILLOMA

PubMed Central

Whang, Junshick

1960-01-01

While it is not the intent to argue that papilloma never develops in the conventionally accepted manner (proliferative growth from the wall of a pre-existing cavity) a new, perhaps alternative, genesis is suggested. The concept is that, beginning with the usual lobular structure of the breast, first by hyperplasia and then by coalescence of alveoli, seen earliest at the periphery of the lobule, spaces appear between the content of the lobule and the wall. By confluence of these spaces a larger cystic cavity is formed. Coalescence of alveoli through the body of the central mass, in the same way as at the periphery, develops the familiar pattern of “papilloma.” Following the earlier hyperplasia, regressive changes appear and may go on to complete disintegration of the papillary mass, leaving a smooth-walled cavity. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6. PMID:13844252

Isotopic, petrologic and biogeochemical investigations of banded iron-formations

NASA Technical Reports Server (NTRS)

Hayes, J. M.; Kaufman, A. J.; Klein, C.; Studley, S. A.; Baur, M. E.; Walter, M. R.

1986-01-01

It is recognized that the first occurrence of banded iron-formations (BIFs) clearly predates biological oxygenation of the atmosphere-hydrosphere system and that their last occurrences extend beyond plausible dates of pervasive biological oxygenation. For this reason, and because enormous quantities of oxidizing power have been sequestered in them, it is widely thought that these massive, but enigmatic, sediments must encode information about the mechanism and timing of the rise of atmospheric O2. By coupling isotopic analyses of iron-formation carbonates with biogeochemical and petrologic investigations, we are studying (1) the mechanism of initial sedimentation of iron; (2) the role of iron in microbially mediated diagenetic processes in fresh iron-formation sediments; and (3) the logical integration of mechanisms of deposition with observed levels of banding. Thus far, it has been shown that (1) carbonates in BIFs of the Hamersley Group of Western Australia are isotopically inhomogenous; (2) the nature and pattern of isotopic ordering is not consistent with a metamorphic origin for the overall depletion of C-13 observed in the carbonates; (3) if biological, the origin of the C-13 depleted carbonate could be either respiratory or fermentative; (4) iron may have been precipitate d as Fe(3+), then reduced to Fe(2+) within the sediment; and (5) sedimentary biogeochemical systems may have been at least partially closed to mass transport of carbonate species.

Variations in large-scale tropical cyclone genesis factors over the western North Pacific in the PMIP3 last millennium simulations

NASA Astrophysics Data System (ADS)

Yan, Qing; Wei, Ting; Zhang, Zhongshi

2017-02-01

Investigation of past tropical cyclone (TC) activity in the Western North Pacific (WNP) is potentially helpful to enable better understanding of future TC behaviors. In this study, we examine variations in large-scale environmental factors important to TC genesis in the last millennium simulations from the Paleoclimate Modelling Intercomparison Project Phase 3 (PMIP3). The results show that potential intensity, a theoretical prediction of the maximum TC intensity, is increased relative to the last millennium in the north part of the WNP in the Medieval Climate Anomaly (MCA; 950-1200 AD) while it is decreased in the Little Ice Age (LIA; 1600-1850 AD). Vertical wind shear that generally inhibits TC genesis is enhanced (reduced) to the south of 20°N and is reduced (enhanced) to the north in the MCA (LIA). Relative humidity (at 600 hPa) that measures the mid-tropospheric moisture content broadly shows an increase (decrease) in the MCA (LIA). A genesis potential index indicates that conditions are generally favorable (unfavorable) for TC formation in the WNP in the MCA (LIA), especially in the northern part. Taking changes in steering flows into account, there may be an increasing (decreasing) favorability for storm strikes in East Asia in the MCA (LIA). The estimated TC activity is consistent with the geological proxies in Japan, but contradicts with the typhoon records in southern China and Taiwan. This model-data discrepancy is attributed to the limitations in both simulations and reconstructions.

Kuhn and the genesis of the "new historiography of science".

PubMed

de Oliveira, J C Pinto

2012-03-01

In this paper I identify a tension between the two sets of works by Kuhn regarding the genesis of the "new historiography of science". In the first, it could be said that the change from the traditional to the new historiography is strictly endogenous (referring to internal causes or reasons). In the second, the change is predominantly exogenous. To address this question, I draw on a text that is considered to be less important among Kuhn's works, but which, as shall be argued, allows some contact between Kuhn's two approaches via Koyré. I seek to point out and differentiate the roles of Koyré and Kuhn--from Kuhn's point of view--in the development of the historiography of science and, as a complement, present some reflections regarding the justification of the new historiography.

Genesis Spacecraft Science Canister Preliminary Inspection and Cleaning

NASA Technical Reports Server (NTRS)

Hittle, J. D.; Calaway, M. J.; Allton, J. H.; Warren, J. L.; Schwartz, C. M.; Stansbery, E. K.

2006-01-01

The Genesis science canister is an aluminum cylinder (75 cm diameter and 35 cm tall) hinged at the mid-line for opening. This canister was cleaned and assembled in an ISO level 4 (Class 10) clean room at Johnson Space Center (JSC) prior to launch. The clean solar collectors were installed and the canister closed in the cleanroom to preserve collector cleanliness. The canister remained closed until opened on station at Earth-Sun L1 for solar wind collection. At the conclusion of collection, the canister was again closed to preserve collector cleanliness during Earth return and re-entry. Upon impacting the dry Utah lakebed at 300 kph the science canister integrity was breached. The canister was returned to JSC. The canister shell was briefly examined, imaged, gently cleaned of dust and packaged for storage in anticipation of future detailed examination. The condition of the science canister shell noted during this brief examination is presented here. The canister interior components were packaged and stored without imaging due to time constraints.

Geological and Petrological Characteristics of Oligocene Magmatic Rocks in The Biga Peninsula, NW Turkey

NASA Astrophysics Data System (ADS)

Erenoglu, Oya

2016-04-01

Oligocene magmatic activity in the Biga Peninsula (NW-Anatolia) produced widespread volcano-plutonic complexes. The study region, where in north of the Evciler village in the middle of Biga Peninsula includes these igneous assemblages. In this study, the petrographic and geochemical characteristics of igneous rocks in the region were investigated as well as the geological locations. The magmatic rocks are classified as 6 different units using their lithostratigraphical properties. The volcanism in the region starts with basaltic andesite lava including basalt dykes in the Lower Oligocene. In the Upper Oligocene, the evolved magma by crustal contamination produced commonly dacitic and andesitic lavas. The volcanism continued with andesitic lavas which had significant alterations in the region during this period. Evciler pluton including granite and granodiorite composition with shallow intrusive, was located with the related volcanism at the same time. The volcanic products, i.e. andesitic and trachydacitic lavas, was completed in the interval between Upper Oligocene and Lower Miocene. The post-collisional Oligocene sequence is associated with calc-alkaline composition and it has middle, high-K. Trace and rare earth elements (REE) diagrams show the enrichment in both large-ion lithophile elements (LILE) and light rare earth elements (LREE) with respect to the high field strength elements (HFSE), and a significant increment in heavy rare earth element consumption (HREE). The features of major, trace and rare earth elements of plutonic and volcanic rocks and the compositional variations of Oligocene volcanic group indicate increasing amounts of partial melting, crustal contamination and/or assimilation. The Oligocene post-collisional volcanism in Biga Peninsula points out the lithospheric mantle source enriched by subduction which controlled by slab break-off and lithospheric delamination. Acknowledgement. This study was supported by Canakkale Onsekiz Mart University

On the Basic Principles of Igneous Petrology

NASA Astrophysics Data System (ADS)

Marsh, B. D.

2014-12-01

How and why Differentiation occurs has dominated Igneous Petrology since its beginning (~1880) even though many of the problems associated with it have been thoroughly solved. Rediscovery of the proverbial wheel with new techniques impedes progress. As soon as thin section petrography was combined with rock and mineral chemistry, rock diversity, compositional suites, and petrographic provinces all became obvious. The masterful 1902 CIPW norm in a real sense solved the chemical mystery of differentiation: rocks are related by the addition and subtraction of minerals in the anciently appreciated process of fractional crystallization. Yet few believed this, even after phase equilibria arrived. Assimilation, gas transfer, magma mixing, Soret diffusion, immiscibility, and other processes had strong adherents, even though by 1897 Becker conclusively showed the ineffectiveness of molecular diffusion in large-scale processes. The enormity of heat to molecular diffusion (today's Lewis no.) should have been convincing; but few paid attention. Bowen did, and he refined and restated the result; few still paid attention. And in spite of his truly masterful command of experiment and field relations in promoting fractional crystallization, Fenner and others fought him with odd arguments. The beauty of phase equilibria eventually dominated at the expense of knowing the physical side of differentiation. Bowen himself saw and struggled with the connection between physical and chemical processes. Progress has come from new concepts in heat transfer, kinetics, and slurry dynamics. The key approach is understanding the dynamic competition between spatial rates of solidification and all other processes. The lesson is clear: Scholarship and combined field, laboratory and technical expertise are critical to understanding magmatic processes. Magma is a limitlessly enchanting and challenging material wherein physical processes buttressed by chemistry govern.

Foliated breccias in the active Portuguese Bend landslide complex, California: bearing on melange genesis

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

Larue, D.K.; Hudleston, P.J.

1987-05-01

The active portion of the Portuguese Bend landslide complex is approximately 3 km/sup 2/ in area and 30-50 m thick. Measured displacement rates range from less than one to greater than 30 mm/day on different parts of the landslide, with total displacements over the last 30 yrs ranging from about 10 to greater than 150 m. Six types of breccia, each locally with a foliated matrix, were recognized in the active landslide complex and are absent outside the landslide complex. Slide-body breccias are of two types, the first formed by extensional fracturing during bulk pure shear at the top ofmore » the landslide (slide-top breccia) and the second by flow of tuffaceous shales and fracture of embedded siliceous shales during simple shear deep in the landslide to the basal decollement (slide-bottom breccias). Slide-margin breccias, also in simple shear, are produced on the lateral margins of individual slide blocks accompanying wrench-fault motion. Other breccias (fault-ramp breccias) are formed during motion over ramps. Colluvial deposits within tension gashes (crack-fill breccias) and at the toe of the slide (slide-toe breccias) represent a fifth breccia type. Diapirs originating from over-pressured zones at the slide base also contain breccia. Recognition of different breccia types in ancient rocks would be difficult, because fabrics in the different types are similar. Foliations are defined by: scaly cleavage, compositional banding and color banding (in shear zones), stretched mud clasts, and aligned hard grains. Foliated breccias are synonymous with melanges. The authors regard the six breccia types described herein as representing the principal types of melange that occur in ancient accretionary settings.« less

Dynamics of Metamorphic Core Complexes Inferred From Modeling and Metamorphic Petrology

NASA Astrophysics Data System (ADS)

Whitney, D. L.; Rey, P.; Teyssier, C.

2008-12-01

Orogenic collapse involves extension and thinning of thick, hot, and in some cases partially molten, crust, leading to the formation of metamorphic core complexes (MCC) that are commonly cored by migmatite domes. 2D numerical modeling predicts that the geometry and P-T-t history of MCC varies as a function of the presence/absence of a partially molten layer in the deep crust; the nature of heterogeneities that localize the MCC (e.g. normal fault in upper crust vs. point-like anomaly in the deep crust); and extensional strain rate. The presence of melt in particular has a significant effect on the thermal and structural history of MCC because the presence of partially molten crust or magma bodies at depth enhances upward advection of material and heat. At high extension rate (cm/year in the region of the MCC), partially molten crust crystallizes as migmatite and cools along a high geothermal gradient (35-65 C/km); material remains partially molten during ascent, forming a migmatite dome when it crystallizes at shallower crustal levels (e.g. cordierite/sillimanite stability field). At low strain rate (mm/yr in the MCC region), the partially molten crust crystallizes at high pressure (e.g. kyanite zone); this material is subsequently deformed in the solid-state along a cooler geothermal gradient (20-35 C/km) during ascent. MCC that develop during extension of partially molten crust may therefore record distinct crystallization versus exhumation histories as a function of extensional strain rate. The mineral assemblages, metamorphic reaction histories, and structures of migmatite-cored (Mc) MCC can therefore be used to interpret the dynamics of MCC formation, e.g. "fast" McMCC in the northern N American Cordillera and Aegean regions.

The evolution of the magmatic arc of Southern Peru (200-60 Ma), Arequipa area: insight from geochemical modeling

NASA Astrophysics Data System (ADS)

Demouy, S.; Benoit, M.; De Saint Blanquat, M.; Brunet, P.

2012-12-01

Cordilleran-type batholiths are built by prolonged arc activity along continental margins and may provide detailed magmatic records of the subduction system evolution. The magmas produced in subduction context involve both mantellic and crustal end members and are subject to various petrological processes. The MASH zones (Hildreth and Moorbath, 1988), at the basis of the continental crust, are the best places for the genesis of such hybrid magmas. The various geochemical signatures observed in the plutonic rocks, may also be attributed to source heterogeneities or generated by subsequent petrological processes. This study has focused in the Arequipa section of the Coastal Batholith of Southern Peru (200-60 Ma), in an area extending over 80x40 km. Major and trace elements as well as Sr and Nd isotopic analyses were performed in a set of 100 samples ranging from gabbro to granite. The obtained data highlight the wide heterogeneity of the geochemical signatures that is not related to the classification of the rocks. In first step, Rb/Sr systematic was used to isolate a set of samples plotting along a Paleocene isochron and defining a cogenetic suite. This suite appears to have evolved by simple fractional crystallization. By using reverse modeling, the parameters controlling the fractional crystallization process were defined, as partition coefficients, initial concentrations and amount of fractional crystallization. The other magmatic suites display a wide range of isotopic and geochemical signatures. To explain this heterogeneity, a model involving competition between fractional crystallization and magma mixing into MASH zones was proposed. A large range of hybrid magma types is potentially generated during the maturation of the system, but this range tends to disappear as fractionation and mixing occurs. Finally the model predicts the genesis of a homogeneous reservoir created at depth, from which magmas may evolve only by fractional crystallization. Therefore

Modeling of unit operating considerations in generating-capacity reliability evaluation. Volume 2. Computer-program documentation. Final report. [GENESIS, OPCON and OPPLAN

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

Patton, A.D.; Ayoub, A.K.; Singh, C.

1982-07-01

This report describes the structure and operation of prototype computer programs developed for a Monte Carlo simulation model, GENESIS, and for two analytical models, OPCON and OPPLAN. It includes input data requirements and sample test cases.

Recent Optical and SEM Characterization of Genesis Solar Wind Concentrator Diamond on Silicon Collector

NASA Technical Reports Server (NTRS)

Allton, Judith H.; Rodriquez, M. C.; Burkett, P. J.; Ross, D. K.; Gonzalez, C. P.; McNamara, K. M.

2013-01-01

One of the 4 Genesis solar wind concentrator collectors was a silicon substrate coated with diamond-like carbon (DLC) in which to capture solar wind. This material was designed for analysis of solar nitrogen and noble gases [1, 2]. This particular collector fractured during landing, but about 80% of the surface was recovered, including a large piece which was subdivided in 2012 [3, 4, 5]. The optical and SEM imaging and analysis described below supports the subdivision and allocation of the diamond-on-silicon (DOS) concentrator collector.

Lateral variation in geochemistry, petrology, and palynology in the Elswick coal bed, Pike County, Kentucky

USGS Publications Warehouse

Hower, J.C.; Ruppert, L.F.; Eble, C.F.

2007-01-01

The Middle Pennsylvanian/Langsettian (Westphalian A) Elswick coal bed, correlative to the Upper Banner of Virginia, is a rare example of a mined high-sulfur (> 2%) coal in Eastern Kentucky, a region known for low-sulfur coals. To characterize lateral variation in the geochemistry, petrography, and palynology of the Elswick coal bed, three sites were sampled along a southeast-northwest transect within a single mine. At the southeastern site, the lower 101??cm of the 116-cm thick coal is dull, generally dominated by durain and dull clarain. While all benches at this site fit within the previously-defined "mixed palynoflora - moderate/low vitrinite group," suggesting a stressed environment of deposition, the palynology of the benches of the dull interval show greater diversity than might be expected just from the petrology. Lithology is generally similar between the sites, but each site has some differences in the petrology. Overall, the coal bed shows significant lateral variation in properties at the mine scale, some of which can be attributed to the gain or loss of upper and lower lithologies, either through an actual physical merging or through the change in character of lithotypes. Sulfur content varies between the three sites examined for this study. Site 3, located in the northwestern portion of the study area is characterized by a strikingly high sulfur zone (7.45%) in the middle of the coal bed, a feature missing at the other sites. Pyrite and marcasite, in a mid-seam lithotype at the northwestern site (site 3), show signs of overgrowths, indicating multiple generations of sulfide emplacement. The high-sulfur site 3 lithologies all have massive overgrowths of euhedral and framboidal pyrite, fracture- and cleat-fill pyrite, and sulfide emplacement in fusinite lumens. Sulfur is high throughout the mine area, but variations are evident in the extent of secondary growth of sulfides. ?? 2006 Elsevier B.V. All rights reserved.

Petrologic considerations for hot dry rock geothermal site selection in the Clear Lake Region, California

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

Stimac, J.; Goff, F.; Hearn, B.C. Jr.

1992-01-01

The Clear Lake area is well known for anomalous heat flow, thermal springs, hydrothermal mineral deposits, and Quaternary volcanism. These factors, along with the apparent lack of a large reservoir of geothermal fluid north of Collayomi fault make the Clear Lake area an attractive target for hot dry rock (HDR) geothermal development. Petrologic considerations provide some constraints on site selection for HDR development. Spatial and temporal trends in volcanism in the Coast Ranges indicate that magmatism has migrated to the north with time, paralleling passage of the Mendocino triple junction and propagation of the San Andreas fault. Volcanism in themore » region may have resulted from upwelling of hot asthenosphere along the southern margin of the subducted segment of the Gorda plate. Spatial and temporal trends of volcanism within the Clear Lake volcanic field are similar to larger-scale trends of Neogene volcanism in the Cost Ranges. Volcanism (especially for silicic compositions) shows a general migration to the north over the {approximately}2 Ma history of the field, with the youngest two silicic centers located at Mt. Konocti and Borax Lake. The Mt. Konocti system (active from {approximately} 0.6 to 0.3 Ma) was large and long-lived, whereas the Borax Lake system is much smaller but younger (0.09 Ma). Remnants of silicic magma bodies under Mt. Konocti may be in the latter stages of cooling, whereas a magma body centered under Borax Lake may be in the early stages of development. The existence of an upper crustal silicic magma body of under Borax Lake has yet to be demonstrated by passive geophysics, however, subsurface temperatures in the area as high (> 200{degrees}C at 2000 m) as those beneath the Mt. Konocti area. Based on petrologic considerations alone, the Mt. Konocti-Borax Lake area appears to be the most logical choice for HDR geothermal development in the region.« less

Clay alteration and gold deposition in the genesis and blue star deposits, Eureka County, Nevada

USGS Publications Warehouse

Drews-Armitage, S. P.; Romberger, S.B.; Whitney, C.G.

1996-01-01

The Genesis and Blue Star sedimentary rock-hosted gold deposits occur within the 40-mile-long Carlin trend and are located in Eureka County, Nevada. The deposits are hosted within the Devonian calcareous Popovich Formation, the siliciclastic Rodeo Creek unit and the siliciclastic Vinini Formation. The host rocks have undergone contact metamorphism, decalcification, silicification, argillization, and supergene oxidation. Detailed characterization of the alteration patterns, mineralogy, modes of occurrence, and associated geochemistry of clay minerals resulted in the following classifications: least altered rocks, found distal to the orebody, consisting of both metamorphosed and unmetamorphosed host rock that has not been completely decalcified; and altered rocks, found proximal to the orebody that have been decalcified. Altered rocks are classified further into the following groups based on clay mineral content: silicic, 1 to 10 percent clay; silicicargillic, 10 to 35 percent clay; and argillic, 35 to 80 percent clay. Clay species identified are 1M illite, 2M1 illite, kaolinite, halloysite, and dioctahedral smectite. An early hydrothermal event resulted in the precipitation of euhedral kaolinite and at least one generation of silica. This event occurred contemporaneously with decalcification which increased rock permeability and porosity. A second clay alteration event resulted in the precipitation of hydrothermal 1M illite which replaced hydrothermal kaolinite and is associated with gold deposition. Silver and silica deposition is also associated with this phase of hydrothermal alteration. Hydrothermal alteration was followed by supergene alteration which resulted in the formation of supergene kaolinite, halloysite, and smectite as well as the oxidation of iron-bearing minerals. Supergene clays are concentrated along faults, dike margins, and within rocks containing carbonate. Gold mineralization is not associated with supergene clay minerals within the Genesis and

Cracking the Code of Soil Genesis. The Early Role of Rare Earth Elements

NASA Astrophysics Data System (ADS)

Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Maier, R. M.; Huxman, T. E.; Chorover, J.

2014-12-01

Soil is terrestrial life support system. Its genesis involves tight interactions between biota and mineral surfaces that mobilize structural elements into biogeochemical cycles. Of all chemical elements rare earth elements (REE) are a group of 16 non-nutrient elements of unusual geochemical similarity and present in all components of the surface environment. While much is known about the role of major nutrients in soil development we lack vital understanding of how early biotic colonization affects more conservative elements such as REE. A highly controlled experiment was set up at University of Arizona's Biosphere-2 that tested the effect of 4 biological treatments, incorporating a combination of microbe, grass, mycorrhiza and uninoculated control on REE leaching and uptake in 4 bedrock substrates: basalt, rhyolite, granite and schist. Generally the response of REE to biota presence was synergistic. Variation in total bedrock chemistry could explain major trends in pore water REE. There was a fast transition from chemistry-dominated to a biota dominated environment in the first 3-4 months of inoculation/seeding which translated into increase in REE signal over time. Relative REE abundances in water were generally reflected in plant concentrations, particularly in root, implying that below ground biomass is the main sync of REE in the ecosystem. Mycorrhiza effect on REE uptake in plant organs was significant and increased with infection rates. Presence of different biota translated into subtle differences in REE release, reveling potential biosignatures of biolota-rock colonization. The results thus bring fundamental insight into early stages non-nutrient cycle and soil genesis.

Deciphering the Minimal Algorithm for Development and Information-genesis

NASA Astrophysics Data System (ADS)

Li, Zhiyuan; Tang, Chao; Li, Hao

During development, cells with identical genomes acquires different fates in a highly organized manner. In order to decipher the principles underlining development, we used C.elegans as the model organism. Based on a large set of microscopy imaging, we first constructed a ``standard worm'' in silico: from the single zygotic cell to about 500 cell stage, the lineage, position, cell-cell contact and gene expression dynamics are quantified for each cell in order to investigate principles underlining these intensive data. Next, we reverse-engineered the possible gene-gene/cell-cell interaction rules that are capable of running a dynamic model recapitulating the early fate decisions during C.elegans development. we further formulized the C.elegans embryogenesis in the language of information genesis. Analysis towards data and model uncovered the global landscape of development in the cell fate space, suggested possible gene regulatory architectures and cell signaling processes, revealed diversity and robustness as the essential trade-offs in development, and demonstrated general strategies in building multicellular organisms.

The genesis of victimization surveys and of the realist-constructionist divide.

PubMed

de Castelbajac, Matthieu

2017-09-01

The invention of victimization surveys is often presented as a synthesis of the two theoretical attitudes that, supposedly, dominated the 1960s debate over official crime statistics: realism and social constructionism. This paper turns this genesis story on its head. Using original archives, I argue that victimization surveys responded to organizational opportunities in the field of applied research. It was only after the fact that two of their architects seized the debate on crime measurement to broadcast their invention. In so doing they strategically recast the terms of this debate into a binary division between two antithetical social ontologies. This case is used to discuss how social scientists come to reinterpret and misunderstand their history. © 2017 Wiley Periodicals, Inc.

Summary of the research work of the Trace Elements Section, Geochemistry and Petrology Branch, for the period April 1, 1948-December 31, 1950

USGS Publications Warehouse

Rabbitt, John C.

1951-01-01

Much of the material in this report has been paraphrased from reports prepared by members of the Section. My special thanks are due them; to Earl Ingerson, chief of the Geochemistry and Petrology Branch of the Survey, for his critical review; to my secretary, Marie Woolihan, for her aid in collecting material; and to Virginia Layne of the editorial staff of the Section for typing the manuscript and the multilith mats.

Rhyolite genesis at the Picabo Volcanic Center of the Snake River Plain: Progressive recycling of hydrothermally altered rhyolites revealed by high resolution analysis of individual zircons

NASA Astrophysics Data System (ADS)

Drew, D.; Bindeman, I. N.; Watts, K. E.; Schmitt, A. K.; McCurry, M. O.

2012-12-01

The Picabo eruptive center of the Snake River Plain (SRP) produced a series of normal and low δ18O rhyolites from 10.44 Ma to 6.62 Ma, providing the first evidence of progressive recycling of hydrothermally altered rhyolites during the formation of a caldera complex. In this study we present a characterization of ignimbrites and associated lavas based on U-Pb ages and δ18O compositions of individual zircon cores measured by ion microprobe, phenocryst δ18O values measured by laser fluorination, whole rock 87Sr/86Sr and 143Nd/144Nd compositions, and whole rock geochemistry. Our data define rhyolite genesis at the Picabo volcanic center through time and have implications for the transition between volcanic centers. Caldera complex evolution at Picabo began with eruption of the 10.44 ± 0.27 Ma Tuff of Arbon Valley (TAV), a chemically zoned unit with a normal δ18Omelt value (8.15‰), very high 87Sr/86Sr (up to 0.734430) and very low ɛNd (-18). Eruptions continued with the ~9.1 Ma Two-and-a-Half-Mile Rhyolite (Kellogg et al., 1988), a unit significant in that it has an even lower ɛNd than the TAV and a normal δ18Omelt value (8.10‰). This low ɛNd of -23, of the Two-and-a-Half-Mile Rhyolite, reveals that greater than 40% of Archean crust was assimilated. These normal δ18O eruptions were followed by a series of lower δ18O eruptions distinguishable by Sr and Nd isotopes and whole rock chemistry. The 8.25 ± 0.26 Ma Rhyolite of West Pocatello has the lowest δ18Omelt value (3.34‰) of these eruptions, and based on nearly identical age, 87Sr/86Sr, 143Nd/144Nd, and whole rock chemistry, we correlate it to a 1,000 m thick intracaldera tuff (present in the INEL drillcore). Along with a distinct decrease in δ18O, from the TAV to the Rhyolite of West Pocatello, there is a corresponding increase in δ18Ozircon heterogeneity from the TAV (1‰ variation) to the low δ18O units with the greatest δ18Ozircon diversity (up to 5‰). Although morphological evidence for

A fully coupled petrological geodynamical model to investigate the evolution of crustal magma chambers

NASA Astrophysics Data System (ADS)

Rummel, Lisa; Kaus, Boris J. P.; White, Richard W.

2017-04-01

The evolution of crustal magma chambers can be considered from a range of different physical and chemical perspectives. Most previous studies focus either on the petrological side (assuming only thermal effects and ignoring mechanics), or on the mechanical evolution (assuming a fixed melt chemistry). Here, we develop a method that fully couples petrological with geodynamic modelling, by combining a finite element code, MVEP2, with a thermodynamic modelling approach (Perple_X) that takes the evolving chemistry into account. The evolution of melt chemistry in a crustal magma chamber is analyzed by focusing on the effects of depth and temperature as well as size and shape of the magma chamber(s). The models show that each of these factors influences the melting behavior of rocks, the magma composition and their effects on the mechanics in the upper lithosphere. Interactions with country rocks (assimilation), ongoing rock depletion (fractional melting) and a possible open system behavior (fractional crystallization) and their effects on magma chemistry are taken into account. The chemical and mineralogical evolution of the melt source, composition (10 oxide component system) of intrusive and extrusive rocks as well as melt fraction and density are tracked on particles using a marker-in-cell-method in the geodynamic code. After each melt extraction event, the employed phase diagram is updated or recalculated based on the residuum chemistry that shifts the solidus to higher temperatures with sequential melt extraction. The resulting wide range in chemical compositions and the volume of intrusive and extrusive rocks are tracked in time and space over the melting region. The newly generated crust employs phase diagrams which are directly computed from the chemistry of extracted melts. Plutons are able to melt again as long as the local temperature is higher in the model than the solidus temperature in the employed phase diagram. As a result, our models make testable

The 2003 phreatomagmatic eruptions of Anatahan volcano - Textural and petrologic features of deposits at an emergent island volcano

USGS Publications Warehouse

Pallister, J.S.; Trusdell, F.A.; Brownfield, I.K.; Siems, D.F.; Budahn, J.R.; Sutley, S.F.

2005-01-01

Stratigraphic and field data are used in conjunction with textural and chemical evidence (including data from scanning electron microscope, electron microprobe, X-ray fluorescence, X-ray diffraction, and instrumental neutron activation analysis) to establish that the 2003 eruption of Anatahan volcano was mainly phreatomagmatic, dominated by explosive interaction of homogeneous composition low-viscosity crystal-poor andesite magma with water. The hydromagmatic mode of eruption contributed to the significant height of initial eruptive columns and to the excavation and eruption of altered rock debris from the sub-volcanic hydrothermal system. Volatile contents of glass inclusions in equilibrium phenocrysts less abundances of these constituents in matrix glass times the estimated mass of juvenile magma indicate minimum emissions of 19 kt SO2 and 13 kt Cl. This petrologic estimate of SO2 emission is an order-of-magnitude less than an estimate from TOMS. Similarly, inferred magma volumes from the petrologic data are an order of magnitude greater than those modeled from deformation data. Both discrepancies indicate additional sources of volatiles, likely derived from a separate fluid phase in the magma. The paucity of near-source volcanic-tectonic earthquakes preceding the eruption, and the dominance of sustained long-period tremor are attributed to the ease of ascent of the hot low-viscosity andesite, followed by a shallow phreatomagmatic mode of eruption. Phreatomagmatic eruptions are probably more common at emergent tropical island volcanoes, where shallow fresh-water lenses occur at near-sea-level vents. These relations suggest that phreatomagmatic explosions contributed to the formation of many of the near-sea-level craters and possibly even to the small calderas at the other Mariana islands.

Genesis Solar Wind Collector Cleaning Assessment: Update on 60336 Sample Case Study

NASA Technical Reports Server (NTRS)

Goreva, Y. S.; Allums, K. K.; Gonzalez, C. P.; Jurewicz, A. J.; Burnett, D. S.; Allton, J. H.; Kuhlman, K. R.; Woolum, D.

2015-01-01

To maximize the scientific return of Genesis Solar Wind return mission it is necessary to characterize and remove a crash-derived particle and thin film surface contamination. A small subset of Genesis mission collector fragments are being subjected to extensive study via various techniques. Here we present an update on the sample 60336, a Czochralski silicon (Si-CZ) based wafer from the bulk array (B/C). This sample has undergone multiple cleaning steps (see the table below): UPW spin wash, aggressive chemical cleanings (including aqua regia, hot xylene and RCA1), as well as optical and chemical (EDS, ToF-SIMS) imaging. Contamination appeared on the surface of 60336 after the initial 2007 UPW cleaning. Aqua regia and hot xylene treatment (8/13/2013) did little to remove contaminants. The sample was UPW cleaned for the third time and imaged (9/16/13). The UPW removed the dark stains that were visible on the sample. However, some features, like "the Flounder" (a large, 100 micron feature in Fig. 1b) appeared largely intact, resisting all previous cleaning efforts. These features were likely from mobilized adhesive, derived from the Post-It notes used to stabilize samples for transport from Utah after the hard landing. To remove this contamination, an RCA step 1 organic cleaning (RCA1) was employed. Although we are still uncertain on the nature of the Flounder and why it is resistant to UPW and aqua regia/hot xylene treatment, we have found RCA1 to be suitable for its removal. It is likely that the glue from sticky pads used during collector recovery may have been a source for resistant organic contamination [9]; however [8] shows that UPW reaction with crash-derived organic contamination does not make particle removal more difficult.

The genesis solar-wind sample return mission

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

Wiens, Roger C

2009-01-01

heterogeneity, each theory predicting a different solar isotopic composition and each invoking a different early solar-system process to produce the heterogeneity. Other volatiles such as C, N, and H may also have experienced similar effects, but with only two isotopes it is often impossible to distinguish with these elements between mass-dependent fractionation and other effects such as mixing or mass-independent fractionation. Table 1 provides a summary of the major measurement objectives of the Genesis mission. Determining the solar oxygen isotopic composition is at the top of the list. Volatile element and isotope ratios constitute six of the top seven priorities. A number of disciplines stand to gain from information from the Genesis mission, as will be discussed later. Based on the Apollo solar-wind foil experiment, the Genesis mission was designed to capture solar wind over orders of magnitude longer duration and in a potentially much cleaner environment than the lunar surface.« less

Petrologic evolution of CM chondrites: The difficulty of discriminating between nebular and parent-body effects. [Abstract only

NASA Technical Reports Server (NTRS)

Kerridge, J. F.; Mcsween, H. Y., Jr.; Bunch, T. E.

1994-01-01

We wish to draw attention to a major controversy that has arisen in the area of CM-chondrite petrology. The problem is important because its resolution will have profound implications for ideas concerning nebular dynamics, gas-solid interactions in the nebula, and accretionary processes in the nebula, among other issues. On the one hand, cogent arguments have been presented that 'accretionary dust mantles,' were formed in the solar nebula prior to accretion of the CM parent asteroid(s). On the other hand, no-less-powerful arguments have been advanced that a significant fraction of the CM lithology is secondary, produced by aqueous alteration in the near-surface regions of an asteroid-sized object. Because most, if not all, CM chondrites are breccias, these two views could coexist harmoniously, were it not for the fact that some of the coarse-grained lithologies surrounded by 'accretion dust mantles' are themselves of apparently secondary origin. Such an observation must clearly force a reassessment of one or both of the present schools of thought. Our objective here is to stimulate such a reassessment. Four possible resolutions of this conflict may be postulated. First, perhaps nature found a way of permitting such secondary alteration to take place in the nebula. Second, maybe dust mantles could form in a regolith, rather than a nebular, environment. Third, it is possible that dust mantles around secondary lithologies are different from those around primary lithologies. Finally, perhaps formation of CM chondrites involved a more complex sequence of events than visualized so far, so that some apparently 'primary' processes postdated certain 'secondary' processes.

Plan for Subdividing Genesis Mission Diamond-on-Silicon 60000 Solar Wind Collector

NASA Technical Reports Server (NTRS)

Burkett, Patti J.; Allton, J. A.; Clemett, S. J.; Gonzales, C. P.; Lauer, H. V., Jr.; Nakamura-Messenger, K.; Rodriquez, M. C.; See, T. H.; Sutter, B.

2013-01-01

NASA's Genesis solar wind sample return mission experienced an off nominal landing resulting in broken, albeit useful collectors. Sample 60000 from the collector is comprised of diamond-like-carbon film on a float zone (FZ) silicon wafer substrate Diamond-on-Silicon (DOS), and is highly prized for its higher concentration of solar wind (SW) atoms. A team of scientist at the Johnson Space Center was charged with determining the best, nondestructive and noncontaminating method to subdivide the specimen that would result in a 1 sq. cm subsample for allocation and analysis. Previous work included imaging of the SW side of 60000, identifying the crystallographic orientation of adjacent fragments, and devising an initial cutting plan.

Cleaning Genesis Solar Wind Collectors with Ultrapure Water: Residual Contaminant Particle Analysis

NASA Technical Reports Server (NTRS)

Allton, J. H.; Wentworth, S. J.; Rodriquez, M. C.; Calaway, M. J.

2008-01-01

Additional experience has been gained in removing contaminant particles from the surface of Genesis solar wind collectors fragments by using megasonically activated ultrapure water (UPW)[1]. The curatorial facility has cleaned six of the eight array collector material types to date: silicon (Si), sapphire (SAP), silicon-on-sapphire (SOS), diamond-like carbon-on-silicon (DOS), gold-on-sapphire (AuOS), and germanium (Ge). Here we make estimates of cleaning effectiveness using image analysis of particle size distributions and an SEM/EDS reconnaissance of particle chemistry on the surface of UPW-cleaned silicon fragments (Fig. 1). Other particle removal techniques are reported by [2] and initial assessment of molecular film removal is reported by [3].

Post-traumatic complex regional pain syndrome: clinical features and epidemiology

PubMed Central

Ratti, Chiara; Nordio, Andrea; Resmini, Giuseppina; Murena, Luigi

2015-01-01

Summary Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that occurs after a tissue injury (fractures, sprain, surgery) of the upper or lower extremities. A clear pathophysiological mechanism has not been established yet and different patterns are considered to play a role in the genesis of the disease. The diagnosis is made by different diagnosis criteria and a gold standard has not been established yet. Incidence of CRPS is unclear and large prospective studies on the incidence and prevalence of CRPS are scarce. The aim of this review is to give an overview on the prevalent data regarding this chronic syndrome. PMID:27134626

A New Approach to Teaching Petrology: Active Learning in a Studio Classroom

NASA Astrophysics Data System (ADS)

Perkins, D.

2003-12-01

During the past 15 years it has become clear that the traditional lecture and lab approach to college science teaching leaves much to be desired. The traditional approach is instructor oriented and based on passive learning. In contrast, current studies show that most students learn best when actively engaged in the learning process. Inquiry based learning and open ended projects have been shown to especially enhance learning by promoting higher order thinking. Recognizing the need for change, however, does not mean the changes are simple. The task of overhauling a course, replacing traditional approaches with more student oriented activities, requires a great deal of time and effort. It also involves much uncertainty and risk. At UND we have been experimenting with alternative pedagogies for a number of years. Change has been incremental, but this year we made wholesale changes in our petrology class. We converted it from the standard three lecture and one lab format to two 3-hour studio sessions per week. The distinction between lab and lecture is gone. In fact, there really are no lectures. The instructor talks for no more than 15 or 20 minutes at a time. Students spend most of their time doing, not listening. We emphasize collaborative active learning projects, some quite short and others lengthy and involved, and use a wide variety of activities. To assess the class, we have an outside consultant and we carry out weekly assessments to measure (1) how students are reacting to the various pedagogical approaches, and (2) how much student learning is actually occurring. This allows us to make adjustments and fine tune as necessary. We could not have made such changes a few years ago, simply because of the amount of work involved to create and test the necessary classroom materials. Today, however, there are many resources available to the reform minded teacher, and the resource base continues to grow. We borrowed heavily from other instructors at other

Genesis of avian influenza H9N2 in Bangladesh.

PubMed

Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2014-12-01

Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011-2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans.

Genesis of avian influenza H9N2 in Bangladesh

PubMed Central

Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2014-01-01

Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011–2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans. PMID:26038507

The Genesis Mission: Solar Wind Conditions, and Implications for the FIP Fractionation of the Solar Wind.

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

Reisenfeld, D. B.; Wiens, R. C.; Barraclough, B. L.

2005-01-01

The NASA Genesis mission collected solar wind on ultrapure materials between November 30, 2001 and April 1, 2004. The samples were returned to Earth September 8, 2004. Despite the hard landing that resulted from a failure of the avionics to deploy the parachute, many samples were returned in a condition that will permit analyses. Sample analyses of these samples should give a far better understanding of the solar elemental and isotopic composition (Burnett et al. 2003). Further, the photospheric composition is thought to be representative of the solar nebula, so that the Genesis mission will provide a new baseline formore » the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. Sample analysis is currently underway. The Genesis samples must be placed in the context of the solar and solar wind conditions under which they were collected. Solar wind is fractionated from the photosphere by the forces that accelerate the ions off of the Sun. This fractionation appears to be ordered by the first ionization potential (FIP) of the elements, with the tendency for low-FIP elements to be over-abundant in the solar wind relative to the photosphere, and high-FIP elements to be under-abundant (e.g. Geiss, 1982; von Steiger et al., 2000). In addition, the extent of elemental fractionation differs across different solarwind regimes. Therefore, Genesis collected solar wind samples sorted into three regimes: 'fast wind' or 'coronal hole' (CH), 'slow wind' or 'interstream' (IS), and 'coronal mass ejection' (CME). To carry this out, plasma ion and electron spectrometers (Barraclough et al., 2003) continuously monitored the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons, and those parameters were in turn used in a rule-based algorithm that assigned the most probable solar wind regime (Neugebauer et al., 2003). At any given time, only one of

Petrology and provenance of Upper Cretaceous Sandstone, southern San Rafael Mountains, Santa Barbara County, California

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

Toyne, C.D.

1987-05-01

Petrologic analysis of 24 medium to coarse-grained sandstone samples, collected from a 2950-m submarine fan complex of late Campanian-early Maestrichtian age exposed within Mono Creek Canyon, reveal commonly calcite cemented, poorly sorted, subangular biotic arkoses. Framework averages 86.0%. Matrix - primarily detrital quartz, feldspar, and lithic fragments finer than 0.03 mm and mechanically and chemically altered phyllosilicates and labile aphanites - averages 8.9%. Calcite cement averages 4.2%. Porosity averages 0.9%. Gazzi-Dickinson point counts of 400 framework grains per slide yield modal averages of Q/sub 37.7/ F/sub 49.8/ L/sub 12.5/; Qm/sub 27.4/ F/sub 49.8/ Lt/sub 22.8/; Qm/sub 35.6/ P/sub 43.7/ K/submore » 20.7/; and Qp/sub 49.4/ Lv/sub 22.1/ Ls/sub 28.5/. P/F averages 0.68, Lv/L averages 0.45, Qp/Q averages 0.27, and detrital phyllosilicate, predominantly biotite, averages 5.7% of total framework. Neither primary nor secondary parameters vary systematically with stratigraphic position. Miscellaneous constituents average 1.3% of framework and include epidote, garnet, amphibole, pyroxene, zircon, and tourmaline as well as carbonaceous blebs, opaque minerals, and unidentifiable lithic fragments. Separate analysis of 100 medium sized quartz grains per slide indicates a mean population of 63.0% non-undulatory monocrystalline quartz, 9.1% undulatory monocrystalline quartz, 10.1% polycrystalline quartz of 2 to 3 crystals, and 17.9% polycrystalline quartz composed of more than 3 crystals. Modal data, plotted upon provenance discrimination diagrams, indicate a plutonic provenance transitional between a dissected magmatic arc and uplifted basement terrane. Paleocurrent data, neglecting possible clockwise rotation, indicate sediment transport from the north.« less

Feasibility of Iodine and Bromine analysis in Genesis AloS collectors

NASA Astrophysics Data System (ADS)

Pravdivtseva, O.; Meshik, A.; Hohenberg, C. M.; Burnett, D. S.

2011-12-01

Comparison of solar, meteoritic and terrestrial elemental abundances provides understanding of the formation and evolution of the solar system. Yet, the majority of the solar abundances are based on meteoritic values [1-6]. As a continuation of our noble gas measurements of the Solar Wind (SW) [7] we attempted to evaluate the possibility of SW-iodine and SW-bromine analyses in the Genesis Solar Wind Aluminum on Sapphire collectors (AloS) using the conversions: 127I(n,γβ)128Xe, 79Br(n,γβ)80Kr and 81Br(n,γβ)82Kr. To estimate the extent of terrestrial halogen contamination in Genesis collectors, several flown fragments of AloS were submerged in methanol (for 1 hour and for 48 hours), rinsed, dried, sealed under vacuum in fused quartz ampoules and irradiated at the Missouri University Research Reactor receiving fluence ˜ 2E+19 thermal neutrons/cm2. Single step laser extraction using 1064 nm laser ablation of 0.7 cm2 area demonstrated clear signature of solar wind as indicated by 129Xe/132Xe = 1.045 ± 0.005, while 128Xe/132Xe = 1.01 ± 0.03 had a 12-fold excess compared to the solar value. Longer washing apparently reduces iodine contamination 4 times, implying that it is surface correlated. Krypton analysis showed 17% excess in 82Kr and 3-fold excess in 80Kr in agreement with their production ratio. A longer 48-hour washing reduced Br contamination 50 times. In order to better separate SW halogens from ubiquitous terrestrial contamination we employed a depth-profiling of AloS using 266 nm laser ablation. Laser beam power was increased in 12 consecutive steps using a combination of controlled defocusing and attenuation by a polarizing beamsplitter. Depth profile analysis revealed that terrestrial halogen contamination is present at the surface and at the interface between Al and sapphire substrate and is more pronounced for iodine, as indicated by 128Xe/132Xe ratio that is higher than atmospheric and solar wind values in all 12 rasters. While washing procedure

COMBINED DELAY AND GRAPH EMBEDDING OF EPILEPTIC DISCHARGES IN EEG REVEALS COMPLEX AND RECURRENT NONLINEAR DYNAMICS.

PubMed

Erem, B; Hyde, D E; Peters, J M; Duffy, F H; Brooks, D H; Warfield, S K

2015-04-01

The dynamical structure of the brain's electrical signals contains valuable information about its physiology. Here we combine techniques for nonlinear dynamical analysis and manifold identification to reveal complex and recurrent dynamics in interictal epileptiform discharges (IEDs). Our results suggest that recurrent IEDs exhibit some consistent dynamics, which may only last briefly, and so individual IED dynamics may need to be considered in order to understand their genesis. This could potentially serve to constrain the dynamics of the inverse source localization problem.

How the Science versus Religion Debate Has Missed the Point of Genesis 1 and 2: Jacques Ellul (1912-1994)

ERIC Educational Resources Information Center

Vanderburg, Willem H.

2010-01-01

From a social and historical perspective, the conflict between science and religion regarding the opening chapters of Genesis in the Jewish and Christian Bibles may have more to do with uncritically reading these texts through our "cultural glasses" than with what these texts actually say. Within the context of his work, Jacques Ellul read these…

The Relation Between Dry Vortex Merger and Tropical Cyclone Genesis over the Atlantic Ocean

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

Chen, Shu-Hua; Liu, Yi-Chin

2014-10-27

A strong, convective African tropical disturbance has a greater chance to develop into a Tropical 23 Depression (TD) if it merges with a shallow, dry vortex (D-vortex) from the north of the African 24 easterly jet (AEJ) after leaving the western coast. Using 11-year reanalysis data we found that the 25 western tip of a vortex strip at northwestern Africa can serve as dry vortices for the D-vortex 26 merger if it shifts southward. Another source of D-vortices is the westward propagating lows 27 along the southern edge of the Saharan air. The D-vortex merger process occurred for 63.5% ofmore » 28 tropical cyclones (TCs) or developing systems over the main development region of the Atlantic 29 Ocean, while it occurred for 54% of non-developing systems. TC genesis could be largely 30 controlled by the large-scale environment, but the differences in characteristics of vortices 31 associated with the D-vortex merger between developing and non-developing systems could 32 potentially help determine their destinies; in general, developing systems were dominated by a 33 more intense and moist south vortex, while non-developing systems were dominated by a north 34 vortex which was more intense, drier, and larger in size. Analysis also shows that 74% of intense 35 developing systems were involved with the D-vortex merger process. More attention needs to be 36 paid to the D-vortex merger and the characteristics of those vortices as they can play significant 37 roles or have a strong indication in Atlantic TC genesis.« less

Petrologic testament to changes in shallow magma storage and transport during 30+ years of recharge and eruption at Kīlauea Volcano, Hawai‘i: Chapter 8

USGS Publications Warehouse

Thornber, Carl R.; Orr, Tim R.; Heliker, Christina; Hoblitt, Richard P.; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

2015-01-01

Petrologic monitoring of Kīlauea Volcano from January 1983 to October 2013 has yielded an extensive record of glass, phenocryst, melt inclusion, and bulk-lava chemistry from well-quenched lava. When correlated with 30+ years of geophysical and geologic monitoring, petrologic details testify to physical maturation of summit-to-rift magma plumbing associated with sporadic intrusion and prolonged magmatic overpressurization. Changes through time in bulk-lava major- and trace-element compositions, along with glass thermometry, record shifts in the dynamic balance of fractionation, mixing, and assimilation processes inherent to magma storage and transport during near-continuous recharge and eruption. Phenocryst composition, morphology, and texture, along with the sulfur content of melt inclusions, constrain coupled changes in eruption behavior and geochemistry to processes occurring in the shallow magmatic system. For the first 17 years of eruption, magma was steadily tapped from a summit reservoir at 1–4 km depth and circulating between 1180 and 1200°C. Furthermore, magma cooled another 30°C while flowing through the 18 km long rift conduit, before erupting olivine-spinel-phyric lava at temperatures of 1150–1170°C in a pattern linked with edifice deformation, vent formation, eruptive vigor, and presumably the flux of magma into and out of the summit reservoir. During 2000–2001, a fundamental change in steady state eruption petrology to that of relatively low-temperature, low-MgO, olivine(-spinel)-clinopyroxene-plagioclase-phryic lava points to a physical transformation of the shallow volcano plumbing uprift of the vent. Preeruptive comagmatic mixing between hotter and cooler magma is documented by resorption, overgrowth, and compositional zonation in a mixed population of phenocrysts grown at higher and lower temperatures. Large variations of sulfur (50 to >1000 ppm) in melt inclusions within individual phenocrysts and among phenocrysts in most samples

An experimental and petrologic investigation of the source regions of lunar magmatism in the context of the primordial differentiation of the moon

NASA Astrophysics Data System (ADS)

Elardo, Stephen M.

The primordial differentiation of the Moon via a global magma ocean has become the paradigm under which all lunar data are interpreted. The success of this model in explaining multiple geochemical, petrologic, and isotopic characteristics lunar geology has led to magma oceans becoming the preferred model for the differentiation of Earth, Mars, Mercury, Vesta, and other large terrestrial bodies. The goal of this work is to combine petrologic analyses of lunar samples with high pressure, high temperature petrologic experiments to place new and detailed constraints the petrogenetic processes that operated during different stages of lunar magmatism, the processes that have acted upon these magmas to obscure their relationship to their mantle source regions, and how those source regions fit into the context of the lunar magma ocean model. This work focuses on two important phases of lunar magmatism: the ancient crust-building plutonic lithologies of the Mg-suite dating to ~4.3 Ga, and the most recent known mare basaltic magmas dating to ~3 Ga. These samples provide insight into the petrogenesis of magmas and interior thermal state when the Moon was a hot, juvenile planet, and also during the last gasps of magmatism from a cooling planet. Chapter 1, focusing on Mg-suite troctolite 76535, presents data on chromite symplectites, olivine-hosted melt inclusions, intercumulus mineral assemblages, and cumulus mineral chemistry to argue that the 76535 was altered by metasomatism by a migrating basaltic melt. This process could effectively raise radioisotope systems above their mineral-specific blocking temperatures and help explain some of the Mg-suite-FAN age overlap. Chapter 2 focuses on lunar meteorites NWA 4734, 032, and LAP 02205, which are 3 of the 5 youngest igneous samples from the Moon. Using geochemical and isotopic data combined with partial melting models, it is shown that these basalts do not have a link to the KREEP reservoir, and a model is presented for low

Evidence for a Single Ureilite Parent Asteroid from a Petrologic Study of Polymict Ureilites

NASA Technical Reports Server (NTRS)

Downes, Hilary; Mittlefehldt, David W.

2006-01-01

Ureilites are ultramafic achondrites composed of olivine and pyroxene, with minor elemental C, mostly as graphite [1]. The silicate composition indicates loss of a basaltic component through igneous processing, yet the suite is very heterogeneous in O isotopic composition inherited from nebular processes [2]. Because of this, it has not yet been established whether ureilites were derived from a single parent asteroid or from multiple parents. Most researchers tacitly assume a single parent asteroid, but the wide variation in mineral and oxygen isotope compositions could be readily explained by an origin in multiple parent asteroids that had experienced a similar evolution. Numerous ureilite meteorites have been found in Antarctica, among them several that are clearly paired (Fig. 1) and two that are strongly brecciated (EET 83309, EET 87720). We have begun a detailed petrologic study of these latter two samples in order to characterize the range of materials in them. One goal is to attempt to determine whether ureilites were derived from a single parent asteroid.

Soil-vegetation feedbacks driving early ecosystems genesis

NASA Astrophysics Data System (ADS)

Gwenzi, Willis; Hinz, Christoph; McGrath, Gavan; Veneklaas, Erik

2010-05-01

During the early phase of terrestrial ecosystems genesis feedbacks between soil and vegetation may become a key driver determining whether and how the systems will converge to a stable state. This is particular true for water-limited ecosystems for which water availability determines biomass. Based on a review of how vegetation growth affects soil hydraulic properties, we propose a simple conceptual model that captures the feedbacks between soil water storage in soil and soil hydraulic behaviour and vegetation biomass. The feedbacks that we considered are (i) vegetation biomass and soil water storage, (ii) root growth and infiltration capacity, (iii) vegetation biomass and bare soil evaporation, and (iv) root growth and soil water drainage. In water-limited environments, these feedbacks are responsible for highly organized vegetation patterns in space and may also lead to oscillating behaviour of soil water storage and vegetation biomass in time. Biomass overshooting as a result of initially high soil water content is predicted, which is consistent with observations made in forested catchments after clearing or during re-vegetation of mine tailings. We furthermore study how the oscillation of rainfall and evaporative demand affects the biomass fluctuations in time. We can show that such systems may converge to either an equilibrium point or a limit cycle. Climate oscillation can cause period doubling and for large periods it may control the biomass dynamics.

Incorporating Problem-Based Learning Into A Petrology Course Through A Research Project In The Local Northern Sierra Nevada

NASA Astrophysics Data System (ADS)

Aird, H. M.

2016-12-01

A research project into the local petrology was integrated into the Spring 2016 Petrology and Optical Mineralogy course at California State University, Chico. This is a required majors course, typically taken during spring of the junior year, with an enrollment of 10-20 students. Since the labs for this course have a strong focus on petrography, a research project was introduced to give students experience in using a multi-faceted approach to investigate a problem. In many cases, this is their first taste of research. During the first week of the Spring 2016 class, students were introduced to the research question: In the broader context of Californian tectonic history, are the Bucks Lake and Grizzly plutons of the northern Sierra Nevada petrogenetically related? With faculty guidance over the course of the semester, students carried out fieldwork and sampling, lithologic description, selection of the best samples for further analysis, thin section production, petrographic description, and analysis and interpretation of published geochemical data. Research activities were strategically scheduled within the course framework such that students were academically prepared to carry out each task. Each student was responsible for generating all the data for one sample, and data were then collated as a class, so students wrote their individual final reports using all the data collected by the class. Careful scaffolding of writing assignments throughout the semester guided students through the preparation of an academic-style scientific report, while allowing for repeated feedback on their writing style and content. In mid-May, the class presented a group poster at the College of Natural Sciences annual poster symposium, and were awarded `Best Student Class Project' by the judges. Anecdotal student feedback indicated they highly valued the research experience and some were inspired to pursue individual undergraduate research projects under faculty supervision.

VARIATIONS IN SOLAR WIND FRACTIONATION AS SEEN BY ACE/SWICS AND THE IMPLICATIONS FOR GENESIS MISSION RESULTS

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

Pilleri, P.; Wiens, R. C.; Reisenfeld, D. B.

We use Advanced Composition Explorer (ACE)/Solar Wind Ion Composition Spectrometer (SWICS) elemental composition data to compare the variations in solar wind (SW) fractionation as measured by SWICS during the last solar maximum (1999–2001), the solar minimum (2006–2009), and the period in which the Genesis spacecraft was collecting SW (late 2001—early 2004). We differentiate our analysis in terms of SW regimes (i.e., originating from interstream or coronal hole flows, or coronal mass ejecta). Abundances are normalized to the low-first ionization potential (low-FIP) ion magnesium to uncover correlations that are not apparent when normalizing to high-FIP ions. We find that relative tomore » magnesium, the other low-FIP elements are measurably fractionated, but the degree of fractionation does not vary significantly over the solar cycle. For the high-FIP ions, variation in fractionation over the solar cycle is significant: greatest for Ne/Mg and C/Mg, less so for O/Mg, and the least for He/Mg. When abundance ratios are examined as a function of SW speed, we find a strong correlation, with the remarkable observation that the degree of fractionation follows a mass-dependent trend. We discuss the implications for correcting the Genesis sample return results to photospheric abundances.« less

Why do magmas stall? Insights from petrologic and geodetic data

NASA Astrophysics Data System (ADS)

Zimmer, M. M.; Plank, T.; Freymueller, J.; Hauri, E. H.; Larsen, J. F.; Nye, C. J.

2007-12-01

Magmas stall at various depths in the crust due to their internal properties (magma viscosity, buoyancy) and external crustal controls (local stress regime, wallrock strength). Annen et al. (JPet 2006) propose a petrological model in which buoyant magma ascends through the crust until the depth of water saturation, after which it crystallizes catastrophically and stalls due to the large increase in magma viscosity. Magmas may erupt from this storage region, or viscous death may result in pluton formation. In order to test this model, and constrain magma storage depths, we combine petrological and geodetic data for several active volcanoes along the Aleutian-Alaska arc. We analyzed glassy, primarily olivine-hosted melt inclusions by SIMS in tephra samples for their pre-eruptive volatile contents, which can be related to the depth of entrapment via pressure-dependent H2O-CO2 solubility models (e.g., VolatileCalc). Melt inclusions are not in equilibrium with pure water vapor (all will contain S and C species), but >50% of the inclusion population are in equilibrium with a vapor containing >85% H2O. Geodetic data (InSAR, GPS) record surface deformation related to volcano inflation/deflation, and can be inverted to solve for the depths of volume change (magma storage) in the crust. In the Aleutians, we find that the maximum melt inclusion trapping depths and geodetic depths correlate, suggesting both techniques record crustal magma storage and crystallization. Melt inclusions from the 1997 Okmok eruption are trapped at ≤3 km; deformation during the eruption and subsequent inflation occurred at 3±0.5 km (Miyagi et al., EPSL 2004; Lu & Masterlark, JGR 2005). At Akutan, melt inclusions and GPS data indicate magma storage at ~5-7 km. Inclusions from flank cones of Makushin yield depths of 7 km, similar to inflation observed beneath the main edifice (6.8 km, Lu et al., JGR 2002). Pleistocene inclusions from Augustine volcano indicate magma storage at 10-18 km, in accord

The mineralogy, petrology, and composition of anomalous eucrite Emmaville

NASA Astrophysics Data System (ADS)

Barrett, T. J.; Mittlefehldt, D. W.; Greenwood, R. C.; Charlier, B. L. A.; Hammond, S. J.; Ross, D. K.; Anand, M.; Franchi, I. A.; Abernethy, F. A. J.; Grady, M. M.

2017-04-01

The Emmaville eucrite is a relatively poorly studied basaltic achondrite with an anomalous oxygen isotope signature. In this study, we report comprehensive mineralogical, petrographic, and geochemical data from Emmaville in order to understand its petrogenesis and relationship with the basaltic eucrites. Emmaville is an unusually fine-grained, hornfelsic-textured metabasalt with pervasive impact melt veins and mineral compositions similar to those of typical basaltic eucrites. The major and trace element bulk composition of Emmaville is also typical of a basaltic eucrite. Three separated individual lithologies were also analyzed for O isotopes; a dark gray fraction (E1), a shocked lithology (E2), and a lighter gray portion (E3). Fractions E1 and E2 shared similar O isotope compositions to the bulk sample (E-B), whereas the lighter gray portion (E3) is slightly elevated in Δ17O and significantly elevated in δ18O compared to bulk. No evidence for any exogenous material is observed in the thin sections, coupled with the striking compositional similarity to typical basaltic eucrites, appears to preclude a simple impact-mixing hypothesis. The O-isotopes of Emmaville are similar to those of Bunburra Rockhole, A-881394, and EET 92023, and thus distinct from the majority of the HEDs, despite having similarities in petrology, mineral, and bulk compositions. It would, therefore, seem plausible that all four of these samples are derived from a single HED-like parent body that is isotopically distinct from that of the HEDs (Vesta) but similar in composition.

Visualizing Complex Environments in the Geo- and BioSciences

NASA Astrophysics Data System (ADS)

Prabhu, A.; Fox, P. A.; Zhong, H.; Eleish, A.; Ma, X.; Zednik, S.; Morrison, S. M.; Moore, E. K.; Muscente, D.; Meyer, M.; Hazen, R. M.

2017-12-01

Earth's living and non-living components have co-evolved for 4 billion years through numerous positive and negative feedbacks. Earth and life scientists have amassed vast amounts of data in diverse fields related to planetary evolution through deep time-mineralogy and petrology, paleobiology and paleontology, paleotectonics and paleomagnetism, geochemistry and geochrononology, genomics and proteomics, and more. Integrating the data from these complimentary disciplines is very useful in gaining an understanding of the evolution of our planet's environment. The integrated data however, represent many extremely complex environments. In order to gain insights and make discoveries using this data, it is important for us to model and visualize these complex environments. As part of work in understanding the "Co-Evolution of Geo and Biospheres using Data Driven Methodologies," we have developed several visualizations to help represent the information stored in the datasets from complimentary disciplines. These visualizations include 2D and 3D force directed Networks, Chord Diagrams, 3D Klee Diagrams. Evolving Network Diagrams, Skyline Diagrams and Tree Diagrams. Combining these visualizations with the results of machine learning and data analysis methods leads to a powerful way to discover patterns and relationships about the Earth's past and today's changing environment.

The contribution of the young Cretaceous Caribbean Oceanic Plateau to the genesis of late Cretaceous arc magmatism in the Cordillera Occidental of Ecuador

NASA Astrophysics Data System (ADS)

Allibon, J.; Monjoie, P.; Lapierre, H.; Jaillard, E.; Bussy, F.; Bosch, D.; Senebier, F.

2008-12-01

The eastern part of the Cordillera Occidental of Ecuador comprises thick buoyant oceanic plateaus associated with island-arc tholeiites and subduction-related calc-alkaline series, accreted to the Ecuadorian Continental Margin from Late Cretaceous to Eocene times. One of these plateau sequences, the Guaranda Oceanic Plateau is considered as remnant of the Caribbean-Colombian Oceanic Province (CCOP) accreted to the Ecuadorian Margin in the Maastrichtien. Samples studied in this paper were taken from four cross-sections through two arc-sequences in the northern part of the Cordillera Occidental of Ecuador, dated as (Río Cala) or ascribed to (Macuchi) the Late Cretaceous and one arc-like sequence in the Chogòn-Colonche Cordillera (Las Orquídeas). These three island-arcs can clearly be identified and rest conformably on the CCOP. In all four localities, basalts with abundant large clinopyroxene phenocrysts can be found, mimicking a picritic or ankaramitic facies. This mineralogical particularity, although not uncommon in island arc lavas, hints at a contribution of the CCOP in the genesis of these island arc rocks. The complete petrological and geochemical study of these rocks reveals that some have a primitive island-arc nature (MgO values range from 6 to 11 wt.%). Studied samples display marked Nb, Ta and Ti negative anomalies relative to the adjacent elements in the spidergrams characteristic of subduction-related magmatism. These rocks are LREE-enriched and their clinopyroxenes show a tholeiitic affinity (FeO T-TiO 2 enrichment and CaO depletion from core to rim within a single crystal). The four sampled cross-sections through the island-arc sequences display homogeneous initial Nd, and Pb isotope ratios that suggest a unique mantellic source for these rocks resulting from the mixing of three components: an East-Pacific MORB end-member, an enriched pelagic sediment component, and a HIMU component carried by the CCOP. Indeed, the ankaramite and Mg

Genesis & the Human Ribcage: An Opportunity to Correct a Misconception & Introduce an Evolution Lesson into the Anatomy Class

ERIC Educational Resources Information Center

Senter, Phil

2013-01-01

Many anatomy students begin the course with a misconception that human males and females do not have the same number of ribs. At the root of that misconception is Genesis 2:21-22, in which God removes a rib from Adam to make Eve. Removal of a body part is a surgical procedure, and one does not pass on the results of surgery to one's offspring. The…

Genesis and shape of natural solution cavities within salt deposits

NASA Astrophysics Data System (ADS)

Gechter, Daniel; Huggenberger, Peter; Ackerer, Philippe; Waber, H. Niklaus

2008-11-01

Since the genesis and shape of natural deep-seated cavities within a salt body are insufficiently understood, the current study tries to shed some light on this topic. To this end, freshwater was pumped slowly through a horizontal borehole in rock salt cores. Owing to fast halite dissolution kinetics, high solubility, and slow inflow rate, halite dissolution took place only in the inflow of the rock salt cylinder. The shape of the created cavities is an approximately symmetrical half cone with a horizontal base facing upward. A conceptual model is presented that is inspired by the experimental results and based on theoretical hydraulic-geochemical considerations, as well as on field observations. It proposes that triangular prism or conically shaped cavities develop within salt under confined conditions, where aggressive water flows upward along a fracture/conduit from an insoluble aquifer into the soluble stratum. Such cavity enlargements may cause land subsidence and structure collapse.

Early Petrologic Processes on the Ureilite Parent Body

NASA Technical Reports Server (NTRS)

Singletary, S. J.; Grove, T. L.

2003-01-01

We present a petrographic and petrologic analysis of 21 olivine-pigeonite ureilites, along with new experimental results on melt compositions predicted to be in equilibrium with ureilite compositions. We conclude that these ureilites are the residues of a partial melting/smelting event. Textural evidence preserved in olivine and pigeonite record the extent of primary smelting. In pigeonite cores, we observe fine trains of iron metal inclusions that formed by the reduction of olivine to pigeonite and metal during primary smelting. Olivine cores lack metal inclusions but the outer grain boundaries are variably reduced by a late-stage reduction event. The modal proportion of pigeonite and percentage of olivine affected by late stage reduction are inversely related and provide an estimation of the degree of primary smelting during ureilite petrogenesis. In our sample suite, this correlation holds for 16 of the 21 samples examined. Olivine-pigeonite-liquid phase equilibrium constraints are used to obtain temperature estimates for the ureilite samples examined. Inferred smelting temperatures range from approximately 1150 C to just over 1300 C and span the range of estimates published for ureilites containing two or more pyroxenes. Temperature is also positively correlated with modal percent pigeonite. Smelting temperature is inversely correlated with smelting depth--the hottest olivine-pigeonite ureilites coming from the shallowest depth in the ureilite parent body. The highest temperature samples also have oxygen isotopic signatures that fall toward the refractory inclusion-rich end of the carbonaceous chondrite-anhydrous mineral (CCAM) slope 1 mixing line. These temperature-depth variations in the ureilite parent body could have been created by a heterogeneous distribution of heat producing elements, which would indicate that isotopic heterogeneities existed in the material from which the ureilite parent body was assembled.

Petrologic evidence for collisional heating of chondritic asteroids

NASA Technical Reports Server (NTRS)

Rubin, Alan E.

1995-01-01

The identification of the mechanism(s) responsible for heating asteroids is among the major problems in planetary science. Because of difficulties with models of electromagnetic induction and the decay of short-lived radionuclides, it is worthwhile to evaluate the evidence for collisional heating. New evidence for localized impact heating comes from the high proportion of relict type-6 material among impact-melt-bearing ordinary chondrites (OC). This relict material was probably metamorphosed by residual heat within large craters. Olivine aggregates composed of faceted crystals with 120 deg triple junctions occur within the melted regions of the Chico and Rose City OC melt rocks; the olivine aggregates formed from shocked, mosaicized olivine grains that underwent contact metamorphism. Large-scale collisional heating is supoorted by the correlation in OC between petrologic type and shock stage; no other heating mechanism can readily account for this correlation. The occurrence of impact-melt-rock clasts in OC that have been metamorphosed along with their whole rocks indicates that some impact events preceded or accompanied thermal metamorphism. Such impacts events, occurring during or shortly after accretion, are probably responsible for substantially melting approximately 0.5% of OC. These events must have heated a larger percentage of OC to subsolidus temperatures sufficient to have caused significant metamorphism. If collisional heating is viable, then OC parent asteroids must have been large; large OC asteroids in the main belt may include those of the S(IV) spectral subtype. Collisional heating is inconsistent with layered ('onion-shell') structures in OC asteroids (wherein the degree of metamorphism increases with depth), but the evidence for such structures is weak. It seems likely that collisional heating played an important role in metamorphosing chondritic asteroids.

Petrology and thermal history of type IA chondrules in the Semarkona (LL3.0) chondrite

NASA Technical Reports Server (NTRS)

Jones, R. H.; Scott, E. R. D.

1989-01-01

Detailed petrologic studies have been made of 15 type IA, Fe-poor, porphyritic olivine chondrules in Semarkona (LL3.0). Major and minor element concentrations in olivines, pyroxenes, and mesostases, and bulk composition so the chondrules are measured along with zoning profiles in the olivine and pyroxene crystals. The mineral compositions and textures are best interpreted in terms of closed system crystallization in which the olivines and pyroxenes crystallized in situ from a melt corresponding to the bulk composition of the chondrule. Relict olivine grains are not found in the chondrules. Crystallization probably occurred at a cooling rate of the order of 1000 C/hr. Precursor materials of the chondrules were composed of two components, one refractory Ca-, Al-, and Ti-rich, and one less refractory Si-, Fe-, Cr-, and Mn-rich. The evidence is consistent with Semarkona being one of the least metamorphosed ordinary chondrites.

The complex emplacement dynamics and tsunami genesis of the 1888 Ritter Island sector collapse from 3D seismic data

NASA Astrophysics Data System (ADS)

Urlaub, M.; Karstens, J.; Berndt, C.; Watt, S. F.; Micallef, A.; Klaucke, I.; Klaeschen, D.; Brune, S.; Kühn, M.

2017-12-01

On March 13 1888, a large sector of the subaerial and submarine edifice of Ritter Island (Papua New Guinea) collapsed and slid into the Bismarck Sea, triggering a tsunami with run-up heights of more than 25 m on the neighboring islands. The tsunami traveled for more than 600 km and caused destruction in several settlements. German colonists described in detail the timing of the arriving waves. During research cruise SO252 onboard RV Sonne, we collected a comprehensive set of multibeam and sediment echosounder data, seafloor video footage, rock samples, 2D seismic profiles, and a 60 km2 high-resolution Pcable 3D seismic cube. This dataset, combined with the historic eyewitness accounts, allows detailed reconstruction of the large-scale volcanic sector collapse and the associated tsunami genesis. The 3D seismic cube reveals a change of emplacement dynamics during the collapse of the volcanic edifice. The initial failure occurred along a deep slide plane extending from the volcanic cone up to 300 m deep into the seafloor sediments adjacent to the volcanic edifice. Movement of large, intact sediment blocks and shortening characterize this deep-rooted mass-movement. In contrast to the well-preserved mobilization structures in the deep part of the volcanic edifice related to the initial phase of mass movement, there are hardly any deposits of the upper part of the volcanic cone comprising of well-stratified volcaniclastic layers. The 2 km3 cone was mobilized in the final stage of the sector collapse and its highly energetic slide mass eroded deeply into the previously emplaced slide deposits. The fast moving mass was channelized between two volcanic ridges, transported into the basin west of Sakar Island, and then deposited more than 30 km away from its source. We interpret the separation into two phases as the result of decoupling of the sliding mass of the cone from the deeper volcanic edifice. This process may be explained by gravitational acceleration of the sliding

Geometric Triangular Chiral Hexagon Crystal-Like Complexes Organization in Pathological Tissues Biological Collision Order

PubMed Central

Díaz, Jairo A.; Jaramillo, Natalia A.; Murillo, Mauricio F.

2007-01-01

The present study describes and documents self-assembly of geometric triangular chiral hexagon crystal like complex organizations (GTCHC) in human pathological tissues.The authors have found this architectural geometric expression at macroscopic and microscopic levels mainly in cancer processes. This study is based essentially on macroscopic and histopathologic analyses of 3000 surgical specimens: 2600 inflammatory lesions and 400 malignant tumours. Geometric complexes identified photographically at macroscopic level were located in the gross surgical specimen, and these areas were carefully dissected. Samples were taken to carry out histologic analysis. Based on the hypothesis of a collision genesis mechanism and because it is difficult to carry out an appropriate methodological observation in biological systems, the authors designed a model base on other dynamic systems to obtain indirect information in which a strong white flash wave light discharge, generated by an electronic device, hits over the lines of electrical conductance structured in helicoidal pattern. In their experimental model, the authors were able to reproduce and to predict polarity, chirality, helicoid geometry, triangular and hexagonal clusters through electromagnetic sequential collisions. They determined that similar events among constituents of extracelular matrix which drive and produce piezoelectric activity are responsible for the genesis of GTCHC complexes in pathological tissues. This research suggests that molecular crystals represented by triangular chiral hexagons derived from a collision-attraction event against collagen type I fibrils emerge at microscopic and macroscopic scales presenting a lateral assembly of each side of hypertrophy helicoid fibers, that represent energy flow in cooperative hierarchically chiral electromagnetic interaction in pathological tissues and arises as a geometry of the equilibrium in perturbed biological systems. Further interdisciplinary studies must

Cleaning at the Edge of Science: NASA's Genesis Mission

NASA Technical Reports Server (NTRS)

Stansbery, Eileen K.; Biesinger, Paul H.

2000-01-01

As part of NASA's continuing exploration of the origins of our solar system, the California Institute of Technology, Jet Propulsion Laboratory, Lockheed Martin Astronautics, Los Alamos National Laboratory, and the Johnson Space Center are working together to develop the Genesis mission to return solar matter for analysis in terrestrial laboratories. These samples will be used to define a baseline for the chemical and isotopic composition of the solar nebula. Deviations from the baseline resulted as the solar system evolved; thus, providing a tracer for materials incorporated into meteorites, comets and planetary bodies. These differences represent "fossil residues" that provide invaluable insight into how the solar nebula evolved to form the planets. We cannot collect a sample of the Sun as we would for a planet; fortunately, solar material comes to us in the form of the solar wind. Ultrapure materials will be exposed at the Earth-Sun L1, outside the Earth's magnetic influence, where solar wind nuclei will be captured for 2 years before returning to Earth in January 2001. The key challenge to obtaining a good sample of solar wind, uncontaminated by terrestrial atoms, is a clean collection surface in a clean sample canister and clean facilities with which to handle the samples for allocation and future reference. The Johnson Space Center QSQ is responsible for contamination control for the mission, for ensuring the cleanliness of collection surfaces and providing a clean environment for their subsequent handling. The level of cleanliness required is high; at the time of analysis (after sample return), the surface contamination by C, N, O must each be less than 10(exp 15) atoms per centimeter squared and for elements other than C, N, O, the number of atoms per centimeter squared of each surface contaminant shall not exceed the estimated solar wind fluence of the species (varies by element between U at approx. 10 (exp 4) atoms per centimeter squared to Fe, Si, Mg, and

Genesis of Interplanetary Intermittent Turbulence: a Case Study of Rope-Rope Magnetic Reconnection

NASA Technical Reports Server (NTRS)

Chian, Abraham C.- L.; Feng, Heng Q.; Hu, Qiang; Loew, Murray H.; Miranda, Rodrigo A.; Munoz, Pablo R.; Sibeck, David G.; Wu, De J.

2016-01-01

In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope-rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event. The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.

Exploring Chondrule and CAI Rims Using Micro- and Nano-Scale Petrological and Compositional Analysis

NASA Astrophysics Data System (ADS)

Cartwright, J. A.; Perez-Huerta, A.; Leitner, J.; Vollmer, C.

2017-12-01

As the major components within chondrites, chondrules (mm-sized droplets of quenched silicate melt) and calcium-aluminum-rich inclusions (CAI, refractory) represent the most abundant and the earliest materials that solidified from the solar nebula. However, the exact formation mechanisms of these clasts, and whether these processes are related, remains unconstrained, despite extensive petrological and compositional study. By taking advantage of recent advances in nano-scale tomographical techniques, we have undertaken a combined micro- and nano-scale study of CAI and chondrule rim morphologies, to investigate their formation mechanisms. The target lithologies for this research are Wark-Lovering rims (WLR), and fine-grained rims (FGR) around CAIs and chondrules respectively, present within many chondrites. The FGRs, which are up to 100 µm thick, are of particular interest as recent studies have identified presolar grains within them. These grains predate the formation of our Solar System, suggesting FGR formation under nebular conditions. By contrast, WLRs are 10-20 µm thick, made of different compositional layers, and likely formed by flash-heating shortly after CAI formation, thus recording nebular conditions. A detailed multi-scale study of these respective rims will enable us to better understand their formation histories and determine the potential for commonality between these two phases, despite reports of an observed formation age difference of up to 2-3 Myr. We are using a combination of complimentary techniques on our selected target areas: 1) Micro-scale characterization using standard microscopic and compositional techniques (SEM-EBSD, EMPA); 2) Nano-scale characterization of structures using transmission electron microscopy (TEM) and elemental, isotopic and tomographic analysis with NanoSIMS and atom probe tomography (APT). Preliminary nano-scale APT analysis of FGR morphologies within the Allende carbonaceous chondrite has successfully discerned

Petrology of blueschist from the Western Himalaya (Ladakh, NW India): Exploring the complex behavior of a lawsonite-bearing system in a paleo-accretionary setting

NASA Astrophysics Data System (ADS)

Groppo, Chiara; Rolfo, Franco; Sachan, Himanshu K.; Rai, Santosh K.

2016-05-01

Although the Himalaya is the archetype of collisional orogens, formed as a consequence of the closure of the Neo-Tethyan ocean separating India from Asia, high-pressure metamorphic rocks are rare. Beside few eclogites, corresponding to the metamorphosed continental Indian crust dragged below Asia or underthrusted beneath southern Tibet, blueschists occur seldom along the Yarlung-Tsangpo Suture zone, i.e. the suture marking the India-Asia collision. These blueschists, mostly interpreted as related to paleo-accretionary prisms formed in response to the subduction of the Neo-Tethyan ocean below the Asian plate, are crucial for constraining the evolution of the India-Asia convergence zone during the closure of the Neo-Tethyan Ocean. In the Western Himalaya, the best occurrence of blueschist is that of the Sapi-Shergol Ophiolitic Mélange in Ladakh. This unit is dominated by volcanoclastic sequences rich in mafic material with subordinate interbedding of metasediments, characterized by very fresh lawsonite blueschist-facies assemblages. In this paper, the lawsonite blueschist-facies metasediments have been petrologically investigated with the aims of (i) constraining the P-T evolution of the Sapi-Shergol Ophiolitic Mélange, (ii) evaluating the influence of Fe2O3 and of H2O on the stability of the high-pressure mineral assemblages, (iii) understanding the processes controlling lawsonite formation and preservation, and (iv) interpreting the P-T evolution of the Sapi-Shergol blueschists in the framework of India-Asia collision. Our results indicate that (i) the Sapi-Shergol blueschists experienced a cold subduction history along a low thermal gradient, up to peak conditions of ca. 470 °C, 19 kbar; furthermore, in order to preserve lawsonite in the studied lithologies, exhumation must have been coupled with significant cooling, i.e. the resulting P-T path is characterized by a clockwise hairpin loop along low thermal gradients (< 8-9 °C/km); (ii) the presence of ferric

Origins of cratonic mantle discontinuities: A view from petrology, geochemistry and thermodynamic models

NASA Astrophysics Data System (ADS)

Aulbach, Sonja; Massuyeau, Malcolm; Gaillard, Fabrice

2017-01-01

Geophysically detectible mid-lithospheric discontinuities (MLD) and lithosphere-asthenosphere boundaries (LAB) beneath cratons have received much attention over recent years, but a consensus on their origin has not yet emerged. Cratonic lithosphere composition and origin is peculiar due to its ultra-depletion during plume or accretionary tectonics, cool present-day geothermal gradients, compositional and rheological stratification and multiple metasomatic overprints. Bearing this in mind, we integrate current knowledge on the physical properties, chemical composition, mineralogy and fabric of cratonic mantle with experimental and thermodynamic constraints on the formation and migration of melts, both below and within cratonic lithosphere, in order to find petrologically viable explanations for cratonic mantle discontinuities. LABs characterised by strong seismic velocity gradients and increased conductivity require the presence of melts, which can form beneath intact cratonic roots reaching to 200-250 km depth only in exceptionally warm and/or volatile-rich mantle, thus explaining the paucity of seismical LAB observations beneath cratons. When present, pervasive interaction of these - typically carbonated - melts with the deep lithosphere leads to densification and thermochemical erosion, which generates topography at the LAB and results in intermittent seismic LAB signals or conflicting seismic, petrologic and thermal LAB depths. In rare cases (e.g. Tanzanian craton), the tops of live melt percolation fronts may appear as MLDs and, after complete lithosphere rejuvenation, may be sites of future, shallower LABs (e.g. North China craton). Since intact cratons are presently tectonomagmatically quiescent, and since MLDs produce both positive and negative velocity gradients, in some cases with anisotropy, most MLDs may be best explained by accumulations (metasomes) of seismically slow minerals (pyroxenes, phlogopite, amphibole, carbonates) deposited during past

Extraction of Solar Wind Nitrogen and Noble Gases From the Genesis Gold Foil Collector

NASA Astrophysics Data System (ADS)

Schlutter, D. J.; Pepin, R. O.

2005-12-01

The Genesis gold foil is a bulk solar wind collector, integrating fluences from all three of the wind regimes. Pyrolytic extraction of small foil samples at Minnesota yielded He fluences, corrected for backscatter, in good agreement with measurements by on-board spacecraft instruments, and He/Ne elemental ratios close to those implanted in collector foils deployed on the lunar surface during the Apollo missions. Isotopic distributions of He, Ne and Ar are under study. Pyrolysis to temperatures above the gold melting point generates nitrogen blanks large enough to obscure the solar-wind nitrogen component. An alternative technique for nitrogen and noble gas extraction, by room-temperature amalgamation of the gold foil surface, will be discussed. Ne and Ar releases in preliminary tests of this technique on small foil samples were close to 100% of the amounts expected from the high-temperature pyrolysis yields, indicating that amalgamation quantitatively liberates gases from several hundred angstroms deep in the gold, beyond the implantation depth of most of the solar wind. Present work is focused on two problems currently interfering with accurate nitrogen measurements at the required picogram to sub-picogram levels: a higher than expected blank likely due to tiny air bubbles rolled into the gold sheet during fabrication, and the presence of a refractory hydrocarbon film on Genesis collector surfaces (the "brown stain") that, if left in place on the foil, shields the underlying gold from mercury attack. We have found, however, that the film is efficiently removed within tens of seconds by oxygen plasma ashing. Potential nitrogen contaminants introduced during the crash of the sample return canister are inert in amalgamation, and so are not hazards to the measurements.

Petrology and geochemistry of Antarctic micrometeorites

NASA Astrophysics Data System (ADS)

Kurat, Gero; Koeberl, Christian; Presper, Thomas; Brandstätter, Franz; Maurette, Michel

1994-09-01

The petrology and geochemistry of twentythree chondritic dust particles with masses of 1-47 μg (sizes 100-400 μm) were recovered from blue ice near Cap Prudhomme, Antarctica, and studied by INAA, ASEM, EMPA, and optical microscopy. Sample selection criteria were irregular shape and (for a subsample) black color, with the aim of studying as many unmelted micrometeorites (MMs) as possible. Of thirteen unmelted MMs, six were phyllosilicate-dominated MMs, and seven were coarsegrained crystalline MMs consisting mainly of olivine and pyroxene. The remaining ten particles were largely melted and consisted of a foamy melt with variable amounts of relic phases (scoriaceous MMs). Thus, of the black particles selected, an astonishing portion, 40% (by number), consisted of largely unmelted MMs. Although unmelted, most phyllosilicate MMs have been thermally metamorphosed to a degree that most of the phyllosilicates were destroyed, but not melted. The original preterrestrial mineralogy is occasionally preserved and consists of serpentine-like phyllosilicates with variable amounts of cronstedtite, tochilinite-like oxides, olivine, and pyroxene. The crystalline MMs consist of olivine, low-Ca pyroxene, tochilinite-like oxides, and occasional Ni-poor metal. Relics in scoriaceous MMs consist of the same phases. Mineral compositions and the coexistence of phyllosilicates with anhydrous phases are typical of CM and CR-type carbonaceous chondrites. However, the olivine/pyroxene ratio (~ 1) and the lack of carbonates, sulfates, and of very Fe-poor, refractory element-rich olivines and pyroxenes sets the MMs apart from CM and CR chondrites. The bulk chemistry of the phyllosilicate MMs is similar to that of CM chondrites. However, several elements are either depleted (Ca, Ni, S, less commonly Na, Mg, and Mn) or enriched (K, Fe, As, Br, Rb, Sb, and Au) in MMs as compared to CM chondrites. Similar depletions and enrichments are also found in the scoriaceous MMs. We suggest that the

Beneficiation of Stillwater Complex Rock for the Production of Lunar Simulants

NASA Technical Reports Server (NTRS)

Rickman, D. L.; Young, C.; Stoeser, D.; Edmunson, J.

2014-01-01

The availability of pure, high calcium plagioclase would be a significant asset in any attempt to manufacture high-quality lunar simulants. A suitable plagioclase product can be obtained from materials obtained from the Stillwater Complex of Montana. The access, geology, petrology, and mineralogy of the relevant rocks and the mill tailings are described here. This study demonstrates successful plagioclase recovery from mill tailings produced by the Stillwater Mine Company. Hydrogen peroxide was used to remove carboxymethyl cellulose from the tailing. The characteristics of the plagioclase products are shown and locked grains are identified as a limit to achievable purity. Based on the experimental results, flowsheets were developed showing how these resources could be processed and made into 'separates' of (1) high calcium plagioclase and (2) orthopyroxene/clinopyroxene with the thought that they would be combined later to make simulant.

The depositional environment and petrology of the White Rim Sandstone Member of the Permian Cutler Formation, Canyonlands National Park, Utah

USGS Publications Warehouse

Steele-Mallory, B. A.

1982-01-01

The White Rim Sandstone Member of the Cutler Formation of Permian age in Canyonlands National Park, Utah, was deposited in coastal eolian and associated interdune environments. This conclusion is based on stratigraphic relationships primary sedimentary structures, and petrologic features. The White Rim consists of two major genetic units. The first represents a coastal dune field and the second represents related interdune ponds. Distinctive sedimentary structures of the coastal dune unit include large- to medium-scale, unidirectional, tabular-planar cross-bedding; high-index ripples oriented parallel to dip direction of the foresets; coarse-grained lag layers; avalanche or slump marks; and raindrop impressions. Cross-bedding measurements suggest the dunes were deposited as transverse ridges by a dominantly northwest to southeast wind. Distinctive sedimentary structures of the interdune pond unit include wavy, horizontally laminated bedding, adhesion ripples, and desiccation polygons. These features may have been produced by alternate wetting and drying of sediment during water-table fluctuations. Evidence of bioturbation is also present in this unit. Petrologic characteristics of the White Rim helped to define the depositional environment as coastal. A crinoid fragment was identified at one location; both units are enriched in heavy minerals, and small amounts of well rounded, reworked glauconite were found in the White Rim throughout the study area. Earlier work indicates that the White Rim sandstone is late Wolfcampian to early Leonardian in age. During this time, the Canyonlands area was located in a depositional area alternately dominated by marine and nonmarine environments. Results of this study suggest the White Rim represents a coastal dune field that was deposited by predominantly on-shore winds during a period of marine transgression.

Containerless high-pressure petrology experiments in the microgravity environment of the Space Station

NASA Technical Reports Server (NTRS)

Boynton, W. V.; DRAKE; HILDEBRAND; JONES; LEWIS; TREIMAN; WARK

1987-01-01

The genesis of igneous rocks on terrestrial planets can only be understood through experiments at pressures corresponding to those in planetary mantles (10 to 50 kbar). Such experiments typically require a piston-cylinder apparatus, and an apparatus that has the advantage of controllable pressure and temperature, adequate sample volume, rapid sample quench, and minimal danger of catastrophic failure. It is proposed to perform high-pressure and high-temperature piston-cylinder experiments aboard the Space Station. The microgravity environment in the Space Station will minimize settling due to density contrasts and may, thus, allow experiments of moderate duration to be performed without a platinoid capsule and without the sample having to touch the container walls. The ideal pressure medium would have the same temperatures. It is emphasized, however, that this proposed experimental capability requires technological advances and innovations not currently available.

Sex hormones and the genesis of autoimmunity.

PubMed

Ackerman, Lindsay S

2006-03-01

The sexually dimorphic prevalence of autoimmune disease remains one of the most intriguing clinical observations among this group of disorders. While sex hormones have long been recognized for their roles in reproductive functions, within the past 2 decades scientists have found that sex hormones are integral signaling modulators of the mammalian immune system. Sex hormones have definitive roles in lymphocyte maturation, activation, and synthesis of antibodies and cytokines. Sex hormone expression is altered among patients with autoimmune disease, and this variation of expression contributes to immune dysregulation. English-language literature from the last 10 years was reviewed to examine the relationship between sex hormones and the function of the mammalian immune system. Approximately 50 publications were included in this review, and the majority were controlled trials with investigator blinding that compared both male and female diseased and normal subjects. The review provided basic knowledge regarding the broad impact of sex hormones on the immune system and how abnormal sex hormone expression contributes to the development and maintenance of autoimmune phenomena, with a focus on systemic lupus erythematosus, as models of "lupus-prone" mice are readily available. Sex hormones affect the function of the mammalian immune system, and sex hormone expression is different in patients with systemic lupus erythematosus than in healthy subjects. Sex hormones play a role in the genesis of autoimmunity. Future research may provide a therapeutic approach that is capable of altering disease pathogenesis, rather than targeting disease sequelae.

Translating Periosteum's Regenerative Power: Insights From Quantitative Analysis of Tissue Genesis With a Periosteum Substitute Implant

PubMed Central

Moore, Shannon R.; Heu, Céline; Yu, Nicole Y.C.; Whan, Renee M.; Knothe, Ulf R.; Milz, Stefan

2016-01-01

An abundance of surgical studies during the past 2 centuries provide empirical evidence of periosteum's regenerative power for reconstructing tissues as diverse as trachea and bone. This study aimed to develop quantitative, efficacy-based measures, thereby providing translational guidelines for the use of periosteum to harness the body's own healing potential and generate target tissues. The current study quantitatively and qualitatively demonstrated tissue generation modulated by a periosteum substitute membrane that replicates the structural constituents of native periosteum (elastin, collagen, progenitor cells) and its barrier, extracellular, and cellular properties. It shows the potentiation of the periosteum's regenerative capacity through the progenitor cells that inhabit the tissue, biological factors intrinsic to the extracellular matrix of periosteum, and mechanobiological factors related to implant design and implementation. In contrast to the direct intramembranous bone generated in defects surrounded by patent periosteum in situ, tissue generation in bone defects bounded by the periosteum substitute implant occurred primarily via endochondral mechanisms whereby cartilage was first generated and then converted to bone. In addition, in defects treated with the periosteum substitute, tissue generation was highest along the major centroidal axis, which is most resistant to prevailing bending loads. Taken together, these data indicate the possibility of designing modular periosteum substitute implants that can be tuned for vectorial and spatiotemporal delivery of biological agents and facilitation of target tissue genesis for diverse surgical scenarios and regenerative medicine approaches. It also underscores the potential to develop physical therapy protocols to maximize tissue genesis via the implant's mechanoactive properties. Significance In the past 2 centuries, the periosteum, a niche for stem cells and super-smart biological material, has been used

Translating Periosteum's Regenerative Power: Insights From Quantitative Analysis of Tissue Genesis With a Periosteum Substitute Implant.

PubMed

Moore, Shannon R; Heu, Céline; Yu, Nicole Y C; Whan, Renee M; Knothe, Ulf R; Milz, Stefan; Knothe Tate, Melissa L

2016-12-01

: An abundance of surgical studies during the past 2 centuries provide empirical evidence of periosteum's regenerative power for reconstructing tissues as diverse as trachea and bone. This study aimed to develop quantitative, efficacy-based measures, thereby providing translational guidelines for the use of periosteum to harness the body's own healing potential and generate target tissues. The current study quantitatively and qualitatively demonstrated tissue generation modulated by a periosteum substitute membrane that replicates the structural constituents of native periosteum (elastin, collagen, progenitor cells) and its barrier, extracellular, and cellular properties. It shows the potentiation of the periosteum's regenerative capacity through the progenitor cells that inhabit the tissue, biological factors intrinsic to the extracellular matrix of periosteum, and mechanobiological factors related to implant design and implementation. In contrast to the direct intramembranous bone generated in defects surrounded by patent periosteum in situ, tissue generation in bone defects bounded by the periosteum substitute implant occurred primarily via endochondral mechanisms whereby cartilage was first generated and then converted to bone. In addition, in defects treated with the periosteum substitute, tissue generation was highest along the major centroidal axis, which is most resistant to prevailing bending loads. Taken together, these data indicate the possibility of designing modular periosteum substitute implants that can be tuned for vectorial and spatiotemporal delivery of biological agents and facilitation of target tissue genesis for diverse surgical scenarios and regenerative medicine approaches. It also underscores the potential to develop physical therapy protocols to maximize tissue genesis via the implant's mechanoactive properties. In the past 2 centuries, the periosteum, a niche for stem cells and super-smart biological material, has been used empirically

Antipsychotics promote GABAergic interneuron genesis in the adult rat brain: Role of heat-shock protein production.

PubMed

Kaneta, Hiroo; Ukai, Wataru; Tsujino, Hanako; Furuse, Kengo; Kigawa, Yoshiyasu; Tayama, Masaya; Ishii, Takao; Hashimoto, Eri; Kawanishi, Chiaki

2017-09-01

Current antipsychotics reduce positive symptoms and reverse negative symptoms in conjunction with cognitive behavioral issues with the goal of restoring impaired occupational and social functioning. However, limited information is available on their influence on gliogenesis or their neurogenic properties in adult schizophrenia brains, particularly on GABAergic interneuron production. In the present study, we used young adult subventricular zone (SVZ)-derived progenitor cells expressing proteoglycan NG2 cultures to examine the oligodendrocyte and GABAergic interneuron genesis effects of several kinds of antipsychotics on changes in differentiation function induced by exposure to the NMDA receptor antagonist MK-801. We herein demonstrated that antipsychotics promoted or restored changes in the oligodendrocyte/GABAergic interneuron differentiation functions of NG2(+) cells induced by the exposure to MK-801, which was considered to be one of the drug-induced schizophrenia model. We also demonstrated that antipsychotics restored heat-shock protein (HSP) production in NG2(+) cells with differentiation impairment. The antipsychotics olanzapine, aripiprazole, and blonanserin, but not haloperidol increased HSP90 levels, which were reduced by the exposure to MK-801. Our results showed that antipsychotics, particularly those recently synthesized, exerted similar GABAergic interneuron genesis effects on NG2(+) neuronal/glial progenitor cells in the adult rat brain by increasing cellular HSP production, and also suggest that HSP90 may play a crucial role in the pathophysiology of schizophrenia and is a key target for next drug development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerothermodynamic Environment Definition for the Genesis Sample Return Capsule

NASA Technical Reports Server (NTRS)

Cheatwood, F. McNeil; Merski, N. Ronald, Jr.; Riley, Christopher J.; Mitcheltree, Robert A.

2001-01-01

NASA's Genesis sample return mission will be the first to return material from beyond the Earth-Moon system. NASA Langley Research Center supported this mission with aerothermodynamic analyses of the sample return capsule. This paper provides an overview of that effort. The capsule is attached through its forebody to the spacecraft bus. When the attachment is severed prior to Earth entry, forebody cavities remain. The presence of these cavities could dramatically increase the heating environment in their vicinity and downstream. A combination of computational fluid dynamics calculations and wind tunnel phosphor thermography tests were employed to address this issue. These results quantify the heating environment in and around the cavities, and were a factor in the decision to switch forebody heat shield materials. A transition map is developed which predicts that the flow aft of the penetrations will still be laminar at the peak heating point of the trajectory. As the vehicle continues along the trajectory to the peak dynamic pressure point, fully turbulent flow aft of the penetrations could occur. The integrated heat load calculations show that a heat shield sized to the stagnation point levels will be adequate for the predicted environment aft of the penetrations.

Can tract element distributions reclaim tectonomagmatic facies of basalts in greenstone assemblages?

NASA Technical Reports Server (NTRS)

Butler, J. C.

1986-01-01

During the past two decades many words have been written both for and against the hypothesis that the tectonic setting of a suite of igneous rocks is retained by the chemical variability within the suite. For example, it is argued that diagrams can be constructed from modern/recent basalt subcompositions within the system Ti-Zr-Y-Nb-Sr such that tectonomagmatic settings can be reclaimed. If one accepts this conclusion, it is tempting to inquire as to how far this hypothesis can be extended into other petrological realms. If chemical variations of metabasalts retain information relating to their genesis (tectonic setting), for example, this would be most helpful in reconstructing the history of basalts from greenstone belts. A discussion follows.

ToF-SIMS Investigation of the Effectiveness of Acid-Cleaning procedures for Genesis Solar Wind Collectors

NASA Technical Reports Server (NTRS)

Goreva, Y. S.; Humanyun, M.; Burnett, D. S.; Jurewicz, A. J.; Gonzalez, C. P.

2014-01-01

ToF-SIMS images of Genesis sample surfaces contain an incredible amount of important information, but they also show that the crash-derived surface contamination has many components, presenting a challenge to cleaning. Within the variability, we have shown that there are some samples which appear to be clean to begin with, e.g. 60471, and some are more contaminated. Samples 60493 and 60500 are a part of a focused study of the effectiveness of aqua regia and/or sulfuric acid cleaning of small flight Si implanted with Li-6 using ToF-SIMS.

Houses and Sheds in Australia: An Exploration of the Genesis and Growth of Neighbourhood Houses and Men's Sheds in Community Settings

ERIC Educational Resources Information Center

Golding, Barry; Kimberley, Helen; Foley, Annette; Brown, Mike

2008-01-01

This article reviews research into the genesis and spread of both neighbourhood houses and learning centres in Victoria and community-based men's sheds in Australia to identify some similarities and differences. Our article asks questions about the gendered communities of practice that underpin houses for women on the one hand, and sheds for men…

GENESIS OF INTERPLANETARY INTERMITTENT TURBULENCE: A CASE STUDY OF ROPE–ROPE MAGNETIC RECONNECTION

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

Chian, Abraham C.-L.; Loew, Murray H.; Feng, Heng Q.

In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad–Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope–rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event.more » The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.« less

Divergent responses of tropical cyclone genesis factors to strong volcanic eruptions at different latitudes

NASA Astrophysics Data System (ADS)

Yan, Qing; Zhang, Zhongshi; Wang, Huijun

2018-03-01

To understand the behaviors of tropical cyclones (TCs), it is very important to explore how TCs respond to anthropogenic greenhouse gases and natural forcings. Volcanic eruptions are a major natural forcing mechanism because they inject sulphate aerosols into the stratosphere, which modulate the global climate by absorbing and scattering solar radiation. The number of Atlantic hurricanes is thought to be reduced following strong tropical eruptions, but whether the response of TCs varies with the locations of the volcanoes and the different ocean basins remains unknown. Here, we use the Community Earth System Model-Last Millennium Ensemble to investigate the response of the large-scale environmental factors that spawn TCs to strong volcanic eruptions at different latitudes. A composite analysis indicates that tropical and northern hemisphere volcanic eruptions lead to significantly unfavorable conditions for TC genesis over the whole Pacific basin and the North Atlantic during the 3 years post-eruption, relative to the preceding 3 years. Southern hemisphere volcanic eruptions result in obviously unfavorable conditions for TC formation over the southwestern Pacific, but more favorable conditions over the North Atlantic. The mean response over the Indian Ocean is generally muted and insignificant. It should be noted that volcanic eruptions impact on environmental conditions through both the direct effect (i.e. on radiative forcing) and the indirect effect (i.e. on El Niño-Southern Oscillation), which is not differentiated in this study. In addition, the spread of the TC genesis response is considerably large for each category of eruptions over each ocean basin, which is also seen in the observational/proxy-based records. This large spread is attributed to the differences in stratospheric aerosol distributions, initial states and eruption intensities, and makes the short-term forecast of TC activity following the next large eruption challenging.

Genesis and Evolution of the Skyrme Model from 1954 TO the Present

NASA Astrophysics Data System (ADS)

Sanyuk, Valery I.

Not widely known facts on the genesis of the Skyrme model are presented in a historical survey, based on Skyrme's earliest papers and on his own published remembrance. We consider the evolution of Skyrme's model description of nuclear matter from the "Mesonic Fluid" model up to its final version, known as the baryon model. We pay special tribute to some well-known ideas in contemporary particle physics which one can find in Skyrme's earlier papers, such as: Nuclear Democracy, the Solitonic Mechanism, the Nonlinear Realization of Chiral Symmetry, Topological Charges, Fermi-Bose Transmutations, etc. It is curious to note in the final version of the Skyrme model gleams of Kelvin's "Vortex Atoms" theory. In conclusion we make a brief analysis of the validity of Skyrme's conjectures in view of recent results and pinpoint some questions which still remain.

Genesis of Hurricane Sandy (2012) Simulated with a Global Mesoscale Model

NASA Technical Reports Server (NTRS)

Shen, Bo-Wen; DeMaria, Mark; Li, J.-L. F.; Cheung, S.

2013-01-01

In this study, we investigate the formation predictability of Hurricane Sandy (2012) with a global mesoscale model. We first present five track and intensity forecasts of Sandy initialized at 00Z 22-26 October 2012, realistically producing its movement with a northwestward turn prior to its landfall. We then show that three experiments initialized at 00Z 16-18 October captured the genesis of Sandy with a lead time of up to 6 days and simulated reasonable evolution of Sandy's track and intensity in the next 2 day period of 18Z 21-23 October. Results suggest that the extended lead time of formation prediction is achieved by realistic simulations of multiscale processes, including (1) the interaction between an easterly wave and a low-level westerly wind belt (WWB) and (2) the appearance of the upper-level trough at 200 hPa to Sandy's northwest. The low-level WWB and upper-level trough are likely associated with a Madden-Julian Oscillation.

Decarbonation in an intracratonic setting: Insight from petrological-thermomechanical modeling

NASA Astrophysics Data System (ADS)

Gonzalez, Christopher M.; Gorczyk, Weronika

2017-08-01

Cratons form the stable core roots of the continental crust. Despite long-term stability, cratons have failed in the past. Cratonic destruction (e.g., North Atlantic Craton) due to chemical rejuvenation at the base of the lithosphere remains poorly constrained numerically. We use 2-D petrological-thermomechanical models to assess cratonic rifting characteristics and mantle CO2 degassing in the presence of a carbonated subcontinental lithospheric mantle (SCLM). We test two tectonothermal SCLM compositions: Archon (depleted) and Tecton (fertilized) using 2 CO2 wt % in the bulk composition to represent a metasomatized SCLM. We parameterize cratonic breakup via extensional duration (7-12 Ma; full breakup), tectonothermal age, TMoho (300-600°C), and crustal rheology. The two compositions with metasomatized SCLMs share similar rifting features and decarbonation trends during initial extension. However, we show long-term (>67 Ma) stability differences due to lithospheric density contrasts between SCLM compositions. The Tecton model shows convective removal and thinning of the metasomatized SCLM during failed rifting. The Archon composition remained stable, highlighting the primary role for SCLM density even when metasomatized at its base. In the short-term, three failed rifting characteristics emerge: failed rifting without decarbonation, failed rifting with decarbonation, and semifailed rifting with dry asthenospheric melting and decarbonation. Decarbonation trends were greatest in the failed rifts, reaching peak fluxes of 94 × 104 kg m-3. Increased TMoho did not alter the effects of rifting or decarbonation. Lastly, we show mantle regions where decarbonation, mantle melting in the presence of carbonate, and preservation of carbonated mantle occur during rifting.

Irreversible and reversible components in the genesis of hypertension by sodium chloride (salt).

PubMed

Tekol, Yalcin

2008-01-01

Despite the abundant studies and overwhelming evidences demonstrating the essential role of salt (sodium chloride) for developing "essential" hypertension (EH), the controversies about salt-hypertension (HT) relations are still continuing. One of important mistakes in this topic is assuming that the HT-producing effect of salt is reversible. The present paper explains the complex nature of salt-HT relations. The deduction was made basing on the studies which investigate the relations between salt and HT. Animal experiments show that HT-producing effect of salt contains irreversible and reversible components. The existence of irreversible component manifests itself in this way: the blood pressure (BP) does not recede to the natural values despite removing of salt exposure. The proportion of BP decreasing after salt exposure termination belongs to the reversible component. Available evidences indicate that the irreversible component is developed in utero, during suckling and, generally, in prepubertal period secondary to salt exposure, however, if the salt exposure extends over more than one period, the HT may be intensified. The consequences of salt exposure during early life of human beings have not been investigated as detailed as in experimental animals, however, there are some clinical trials and epidemiological observations indicating that, similar to experimental animals, irreversible and reversible components are also developed in man during the genesis of HT. By the introduction of irreversible and reversible components notion, some obscured items on salt-HT relations can be clarified. For example, some intervention studies could not find dramatic relations between salt and HT, because these interventions modify only the reversible component, but irreversible component remains unchanged. As a result, salt exposure is detrimental for each period of life. For eradication of HT, it is prerequisite to prevent all individuals (especially pregnant or lactating

Mesozoic units in SE Rhodope (Bulgaria): new structural and petrologic data and geodynamic implications for the Early Jurassic to Mid-Cretaceous evolution of the Vardar ocean basin

NASA Astrophysics Data System (ADS)

Bonev, N.; Stampfli, G.

2003-04-01

In the southeastern Rhodope, both in southern Bulgaria and northern Greece, Mesozoic low-grade to non-metamorphic units, together with similar units in the eastern Vardar zone, were designated as the Circum-Rhodope Belt (CRB) that fringes the Rhodope high-grade metamorphic complex. In the Bulgarian southeastern Rhodope, Mesozoic units show a complicated tectono-stratigraphy underlaid by amphibolite-facies basement units. The basement sequence includes a lower orthogneiss unit with eclogite and meta-ophiolite lenses overlain by an upper marble-schist unit, presumably along a SSW-directed detachment fault as indicated by shear sense indicators. The Mesozoic sequence starts with greenschist units at the base, overlaying the basement along the tectonic contact. Mineral assemblages such as actinolite-chlorite-white mica ± garnet in schists and phyllites indicate medium greenschist facies metamorphism. Kinematic indicators in the same unit demonstrate a top-to-the NNW and NNE shear deformation coeval with metamorphism, subparallel to NW-SE to NE-SW trending mineral elongation lineation and axis of NW vergent small-scale folds. The greenschist unit is overlain by tectonic or depositional contact of melange-like unit that consists of diabases with Lower Jurassic radiolarian chert interlayers, Upper Permian siliciclastics and Middle-Upper Triassic limestones found as blocks in olistostromic member, embedded in Jurassic-Lower Cretaceous turbiditic matrix. The uppermost sedimentary-volcanogenic unit is represented by andesito-basalt lavas and gabbro-diorites, interbedded with terrigeneous-marl and tufaceous sediments that yield Upper Cretaceous (Campanian) fossils, related to the Late Cretaceous back-arc magmatic activity to the north in Sredna Gora zone. Petrologic and geochemical data indicates sub-alkaline and tholeiitic character of the greenschists and ophiolitic basaltic lavas, and the latter are classified as low-K and very low-Ti basalts with some boninitic affinity

Petrology and Geochemistry of Mercury

NASA Astrophysics Data System (ADS)

Weider, Shoshana Z.

2018-04-01

concentrations of the volatile elements Na, S, K, and Cl. Furthermore, the total surface Fe abundance is now known to be <2 wt%, and the planet's low reflectance is thought to be primarily caused by the presence of C (in graphite) at a level of >1 wt%. Such data are key to constraining models for Mercury's formation and early evolution. Large-scale spatial variations in the MESSENGER geochemical datasets have also led to the designation of several geochemical "terrains" across Mercury's surface, which do not always align to otherwise mapped geological regions. Based on the MESSENGER geochemical results, several recent petrological experiments and calculations have been, and continue to be, performed to study Mercury's surface mineralogy. The results show that there are substantial differences in the precise mineral compositions and abundances among the different terrains, but Mercury's surface appears to be dominated by Mg-rich olivines and pyroxenes, as well as plagioclase and sulphide phases. Depending on the classification scheme used, Mercury's ultramafic surface rocks can thus be described as similar in nature to terrestrial boninites, andesites, norites, or gabbros.

Petrologic Constraints on Magma Plumbing Systems Beneath Hawaiian Volcanoes

NASA Astrophysics Data System (ADS)

Li, Y.; Peterman, K. J.; Scott, J. L.; Barton, M.

2016-12-01

We have calculated the pressures of partial crystalliztion of basaltic magmas from Hawaii using a petrological method. A total of 1576 major oxide analyses of glasses from four volcanoes (Kilauea and the Puna Ridge, Loihi, Mauna Loa, and Mauna Kea, on the Big Island) were compiled and used as input data. Glasses represent quenched liquid compositions and are ideal for calculation of pressures of partial crystallization. The results were filtered to exclude samples that yielded unrealistic high errors associated with the calculated pressure or negative value of pressure, and to exclude samples with non-basaltic compositions. Calculated pressures were converted to depths of partial crystallization. The majority (68.2%) of pressures for the shield-stage subaerial volcanoes Kilauea, Mauna Loa, and Mauna Kea, fall in the range 0-140 MPa, corresponding to depths of 0-5 km. Glasses from the Puna Ridge yield pressures ranging from 18 to 126 MPa and are virtually identical to pressures determined from glasses from Kilauea (0 to 129 MPa). These results are consistent with the presence of magma reservoirs at depths of 0-5 km beneath the large shield volcanoes. The inferred depth of the magma reservoir beneath the summit of Kilauea (average = 1.8 km, maximum = 5 km) agrees extremely well with depths ( 2-6 km) estimated from seismic studies. The results for Kilauea and Mauna Kea indicate that significant partial crystallization also occurs beneath the summit reservoirs at depths up to 11 km. These results are consistent with seismic evidence for the presence of a magma reservoir at 8-11 km beneath Kilauea at the base of the volcanic pile. The results for Loihi indicate crystallization at higher average pressures (100-400 MPa) and depths (3-14 km) than the large shield volcanoes, suggesting that the plumbing system is not yet fully developed, and that the Hawaiian volcanic plumbing systems evolve over time.

Adventures in Parallel Processing: Entry, Descent and Landing Simulation for the Genesis and Stardust Missions

NASA Technical Reports Server (NTRS)

Lyons, Daniel T.; Desai, Prasun N.

2005-01-01

This paper will describe the Entry, Descent and Landing simulation tradeoffs and techniques that were used to provide the Monte Carlo data required to approve entry during a critical period just before entry of the Genesis Sample Return Capsule. The same techniques will be used again when Stardust returns on January 15, 2006. Only one hour was available for the simulation which propagated 2000 dispersed entry states to the ground. Creative simulation tradeoffs combined with parallel processing were needed to provide the landing footprint statistics that were an essential part of the Go/NoGo decision that authorized release of the Sample Return Capsule a few hours before entry.

Volcanologic and petrologic evolution of Antuco-Sierra Velluda, Southern Andes, Chile

NASA Astrophysics Data System (ADS)

Martínez, Paola; Singer, Brad S.; Roa, Hugo Moreno; Jicha, Brian R.

2018-01-01

The Andean Southern Volcanic Zone comprises > 30 active arc front volcanoes that grew over periods of hundreds of thousands of years. Quantifying the rates at which these volcanoes grow is key to appreciating geological hazards, clarifying petrologic evolution, and exploring possible relationships between volcanism, ice loading, and climate. The integration of precise geochronology and geologic mapping, together with new lava compositions and volume estimates, reveal the evolution of the Antuco-Sierra Velluda volcanic complex at 37.2°S. Thirty-one new 40Ar/39Ar age determinations illuminate a punctuated eruptive history that spans at least 430 kyr. Sierra Velluda comprises 130 km3 and began to grow prior to 426.8 ka. A lacuna in the volcanic record between 343.5 and 150.4 ka coincides with glaciations associated with marine isotope stages (MIS) 10 and 8, although shallow intrusions were emplaced at 207.0 and 190.0 ka. Antuco began to grow rapidly on the northeast flank of Sierra Velluda, erupting > 60 km3 of lava during three phases: (1) an early phase that began at 150.4 ka, (2) a post-MIS 2 phase between 16.3 and 6.2 ka, and (3) a post-sector collapse phase after 6.2 ka. Volcanism has been continuous during the last 100 kyr, with an average rate of cone growth during this period of 0.46 km3/kyr that has accelerated by about 50% during the past 6 kyr. Whereas Sierra Velluda erupted basaltic andesitic to andesitic (53.5 to 58.7 wt% SiO2) lavas, during the last expansion of glaciers between 130 and 17 ka, Early Antuco erupted a wider spectrum of lavas, ranging from basaltic andesite to dacite (52.0 to 64.5 wt% SiO2). Notably, eruptions following the last glacial termination at 17 ka produced basalts and basaltic andesites (50.9-53.7% SiO2), and following the 6.2 ka cone collapse they have been exclusively olivine basalt (50.9-53.0% SiO2) with > 5 wt% MgO. Thermodynamic and trace element modeling suggests that lavas from Sierra Velluda and Early Antuco reflect

Tectonic control on the genesis of magmas in the New Hebrides arc (Vanuatu)

NASA Astrophysics Data System (ADS)

Beier, Christoph; Brandl, Philipp A.; Lima, Selma M.; Haase, Karsten M.

2018-07-01

We present here new bathymetric, petrological and geochemical whole rock, glass and mineral data from the submarine Epi volcano in the New Hebrides (Vanuatu) island arc. The structure has previously been interpreted to be part of a larger caldera structure but new bathymetric data reveal that the volcanic cones are aligned along shear zones controlled by the local tectonic stress field parallel to the recent direction of subduction. We aim to test if there is an interaction between local tectonics and magmatism and to what extent the compositions of island arc volcanoes may be influenced by their tectonic setting. Primitive submarine Epi lavas and those from the neighbouring Lopevi and Ambrym islands originate from a depleted mantle wedge modified by addition of subduction zone components. Incompatible element ratios sensitive to fluid input (e.g., Th/Nb, Ce/Yb) in the lavas are positively correlated with those more sensitive to mantle wedge depletion (e.g., Nb/Yb, Zr/Nb) amongst the arc volcanoes suggesting that fluids or melts from the subducting sediments have a stronger impact on the more depleted compositions of the mantle wedge. The whole rock, glass and mineral major and trace element compositions and the occurrence of exclusively normally zoned clinopyroxene and plagioclase crystals combined with the absence of inversely zoned crystals and water-bearing phases in both mafic and evolved lavas suggest that the erupted melt was relatively dry compared to other subduction zone melts and has experienced little disequilibrium modification by melt mixing or assimilation. Our data also imply that differentiation of amphibole is not required to explain the incompatible element patterns but may rather result from extensive clinopyroxene fractionation in agreement with petrographic observations. Thermobarometric calculations indicate that the melts fractionated continuously during ascent, contrasting with fractionation during stagnation in an established crustal magma

Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics.

PubMed

Leichtle, Ulf G; Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I; Wülker, Nikolaus; Lorenz, Andrea

2017-01-01

In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt ( p < 0.05 for 35°-80° flexion) and translation of the patella ( p < 0.045 for 20°-65° and 75°-90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA.

Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics

PubMed Central

Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I.; Wülker, Nikolaus

2017-01-01

In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p < 0.05 for 35°–80° flexion) and translation of the patella (p < 0.045 for 20°–65° and 75°–90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA. PMID:28255225

MoonDB: Restoration and Synthesis of Lunar Petrological and Geochemical Data

NASA Technical Reports Server (NTRS)

Lehnert, Kerstin A.; Cai, Yue; Mana, Sara; Todd, Nancy S.; Zeigler, Ryan A.; Evans, Cindy A.

2016-01-01

About 2,200 samples were collected from the Moon during the Apollo missions, forming a unique and irreplaceable legacy of the Apollo program. These samples, obtained at tremendous cost and great risk, are the only samples that have ever been returned by astronauts from the surface of another planetary body. These lunar samples have been curated at NASA Johnson Space Center and made available to the global research community. Over more than 45 years, a vast body of petrological, geochemical, and geochronological studies of these samples have been amassed, which helped to expand our understanding of the history and evolution of the Moon, the Earth itself, and the history of our entire solar system. Unfortunately, data from these studies are dispersed in the literature, often only available in analog format in older publications, and/or lacking sample metadata and analytical metadata (e.g., information about analytical procedure and data quality), which greatly limits their usage for new scientific endeavors. Even worse is that much lunar data have never been published, simply because no forum existed at the time (e.g., electronic supplements). Thousands of valuable analyses remain inaccessible, often preserved only in personal records, and are in danger of being lost forever, when investigators retire or pass away. Making these data and metadata publicly accessible in a digital format would dramatically help guide current and future research and eliminate duplicated analyses of precious lunar samples.

Magmatic differentiation processes at Merapi Volcano: inclusion petrology and oxygen isotopes

NASA Astrophysics Data System (ADS)

Troll, Valentin R.; Deegan, Frances M.; Jolis, Ester M.; Harris, Chris; Chadwick, Jane P.; Gertisser, Ralf; Schwarzkopf, Lothar M.; Borisova, Anastassia Y.; Bindeman, Ilya N.; Sumarti, Sri; Preece, Katie

2013-07-01

Indonesian volcano Merapi is one of the most hazardous volcanoes on the planet and is characterised by periods of active dome growth and intermittent explosive events. Merapi currently degasses continuously through high temperature fumaroles and erupts basaltic-andesite dome lavas and associated block-and-ash-flows that carry a large range of magmatic, coarsely crystalline plutonic, and meta-sedimentary inclusions. These inclusions are useful in order to evaluate magmatic processes that act within Merapi's plumbing system, and to help an assessment of which phenomena could trigger explosive eruptions. With the aid of petrological, textural, and oxygen isotope analysis we record a range of processes during crustal magma storage and transport, including mafic recharge, magma mixing, crystal fractionation, and country rock assimilation. Notably, abundant calc-silicate inclusions (true xenoliths) and elevated δ18O values in feldspar phenocrysts from 1994, 1998, 2006, and 2010 Merapi lavas suggest addition of limestone and calc-silicate materials to the Merapi magmas. Together with high δ13C values in fumarole gas, crustal additions to mantle and slab-derived magma and volatile sources are likely a steady state process at Merapi. This late crustal input could well represent an eruption trigger due to sudden over-pressurisation of the shallowest parts of the magma storage system independently of magmatic recharge and crystal fractionation. Limited seismic precursors may be associated with this type of eruption trigger, offering a potential explanation for the sometimes erratic behaviour of Merapi during volcanic crises.

On gravity's role in the genesis of rest masses of classical fields

NASA Astrophysics Data System (ADS)

Szabados, László B.

2018-03-01

It is shown that in the Einstein-conformally coupled Higgs-Maxwell system with Friedman-Robertson-Walker symmetries the energy density of the Higgs field has stable local minimum only if the mean curvature of the t=const hypersurfaces is less than a finite critical value χ _c, while for greater mean curvature the energy density is not bounded from below. Therefore, there are extreme gravitational situations in which even quasi-locally defined instantaneous vacuum states of the Higgs sector cannot exist, and hence one cannot at all define the rest mass of all the classical fields. On hypersurfaces with mean curvature less than χ _c the energy density has the `wine bottle' (rather than the familiar `Mexican hat') shape, and the gauge field can get rest mass via the Brout-Englert-Higgs mechanism. The spacelike hypersurface with the critical mean curvature represents the moment of `genesis' of rest masses.

A petrologic, thermodynamic and experimental study of brachinites: Partial melt residues of an R chondrite-like precursor

NASA Astrophysics Data System (ADS)

Gardner-Vandy, Kathryn G.; Lauretta, Dante S.; McCoy, Timothy J.

2013-12-01

The primitive achondrites provide a window into the initial melting of asteroids in the early solar system. The brachinites are olivine-dominated meteorites with a recrystallized texture that we and others interpret as evidence of partial melting and melt removal on the brachinite parent body. We present a petrologic, thermodynamic and experimental study of the brachinites to evaluate the conditions under which they formed and test our hypothesis that the precursor material to the brachinites was FeO-rich compared to the precursors of other primitive achondrites. Petrologic analysis of six brachinites (Brachina, Allan Hills (ALH) 84025, Hughes 026, Elephant Moraine (EET) 99402, Northwest Africa (NWA) 3151, and NWA 4969) and one brachinite-like achondrite (NWA 5400) shows that they are meteorites with recrystallized texture that are enriched in olivine (⩾80 vol.%) and depleted in other minerals with respect to a chondritic mineralogy. Silicates in the brachinites are FeO-rich (Fa32-36). Brachinite-like achondrite Northwest Africa 5400 is similar in mineralogy and texture to the brachinites but with a slightly lower FeO-content (Fa30). Thermodynamic calculations yield equilibration temperatures above the Fe,Ni-FeS cotectic temperature (∼950 °C) for all meteorites studied here and temperatures above the silicate eutectic (∼1050 °C) for all but two. Brachina formed at an fO2 of ∼IW, and the other brachinites and NWA 5400 formed at ∼IW - 1. All the meteorites show great evidence of formation by partial melting having approximately chondritic to depleted chondritic mineralogies, equilibrated mineral compositions, and recrystallized textures, and having reached temperatures above that required for melt generation. In an attempt to simulate the formation of the brachinite meteorites, we performed one-atmosphere, gas-mixing partial melting experiments of R4 chondrite LaPaz Ice Field 03639. Experiments at 1250 °C and an oxygen fugacity of IW - 1 produce residual

Zircon reveals protracted magma storage and recycling beneath Mount St. Helens

USGS Publications Warehouse

Claiborne, L.L.; Miller, C.F.; Flanagan, D.M.; Clynne, M.A.; Wooden, J.L.

2010-01-01

Current data and models for Mount St. Helens volcano (Washington, United States) suggest relatively rapid transport from magma genesis to eruption, with no evidence for protracted storage or recycling of magmas. However, we show here that complex zircon age populations extending back hundreds of thousands of years from eruption age indicate that magmas regularly stall in the crust, cool and crystallize beneath the volcano, and are then rejuvenated and incorporated by hotter, young magmas on their way to the surface. Estimated dissolution times suggest that entrained zircon generally resided in rejuvenating magmas for no more than about a century. Zircon elemental compositions reflect the increasing influence of mafic input into the system through time, recording growth from hotter, less evolved magmas tens of thousands of years prior to the appearance of mafic magmas at the surface, or changes in whole-rock geochemistry and petrology, and providing a new, time-correlated record of this evolution independent of the eruption history. Zircon data thus reveal the history of the hidden, long-lived intrusive portion of the Mount St. Helens system, where melt and crystals are stored for as long as hundreds of thousands of years and interact with fresh influxes of magmas that traverse the intrusive reservoir before erupting. ?? 2010 Geological Society of America.

Using experimental petrology to constrain genesis of wet, silicic magmas in the Tonga-Kermadec island arc

NASA Astrophysics Data System (ADS)

Brens, R.; Rushmer, T. A.; Turner, S.; Adam, J.

2012-12-01

The Tongan arc system is comprised of a pair of island chains, where the western chain is the active volcanic arc. A range of rock suites, from basaltic andesites (53-56% SiO2) to dacites (64-66% SiO2), has been recovered from Late, Tofua and Fonualei in the Tonga-Kermadec primitive island arc system. For which the question arises: What is the mechanism that allows for silicic magmas to develop in a primitive island arc system? Caufield et al. (2012) suggest that fractional crystallization of a multi magma chamber process, with varying depth, is responsible for the silicic magma generation in this arc. Models such as this one have been proposed and experimentally tested in other systems (Novarupta, Alaska) to explain the origin of these silicic rocks. Our Tongan suite of rocks has had a full geochemical analysis for majors, traces and isotopes. The lavas from Tofua and Late are Fe-rich and have low concentrations of K, Rb, Ba, Zr, REE, Pb and U. However, experimental studies are needed to complement the extensive geochemical analysis done on the Tongan arc. Former geochemical work done on the igneous rocks from both of these volcanic suites from this arc suggests that the source of these rocks extend from 1.5-5.5 km in depth (Caulfield et al., 2012). Here, we present an experimental study of the phase equilibria on a natural andesitic sample (Late 1, from Ewart et al., 1975) from the island of Late. Experiments were run using the temperature constraints between 900 to 1220oC, pressure from 5 to 25 kbars and H2O addition of mostly 5wt% (but some results were obtained at 2wt% in the rocks). In the presence of 5 wt% water, phase equilibria of these experiments show the garnet stability field at >10 kb for 900 oC and increases with increasing temperature, while plagioclase enters at lower pressures when garnet exits. Experimental results currently suggests, at lower temperatures (900-950oC), a fractional crystallization relationship due to shallow level pressures of these rocks and further reinforcing Brophy's (2009) model of crystal fractionation of basalt to dacite in the presence of water, as an important process for which silica-rich magmas are produced within a primitive oceanic island arc.

Petrologic Evolution of Lavas Erupted between 13N and 14N, Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Bendana, S.; Wanless, V. D.; Kurz, M. D.; Soule, S. A.; Mittelstaedt, E. L.; Fornari, D. J.; Lytle, M. L.

2017-12-01

Along many slow spreading ridge segments, the morphology of the axis varies from a symmetric central rift valley where magmatism accommodates a relatively higher proportion of plate spreading to a deeper, asymmetric axial valley where faulting and ductile deformation dominate and oceanic core complexes are common. This transition in morphology correlates with changes in lithospheric thickness, which may influence the total extents of melting and erupted lava compositions. To explore how magmatic processes vary along a slow spreading mid-ocean ridge, we sampled the Mid-Atlantic Ridge (MAR) from 13° 46'N to 14° 06'N on the R/V Atlantis using AUV Sentry and HOV Alvin. Three sections of the ridge were investigated in detail: (1) the asymmetrically spreading (magma-poor) section of the MAR at 13° 48'N, (2) the symmetrically spreading (magma-rich) center of the segment, near 14° 04'N, and (3) the transition between the two sections. To determine how crystallization depths and melting systematics vary from a magma-rich to magma-poor segment, we analyzed all the lavas for major element concentrations by electron microprobe and a subset of lavas for trace element contents using solution ICP-MS. Preliminary geochemical results from the magma-poor region indicate the eruption of a range of slightly to moderately enriched basaltic compositions. Out of 134 samples, fifteen samples collected in the magma-poor region are "popping rocks", containing a high abundance of vesicles and elevated volatile and noble gas contents. All "popping rocks" collected are relatively homogeneous in composition (e.g. [La]N 39-42, [Sm]N 22-24; K2O/TiO2 0.32-0.35) compared to the other lavas erupted in the magma-poor region (e.g. [La]N 13-47, [Sm]N 11-24; K2O/TiO2 0.17-0.5). This suggests that the non-popping rocks formed from variable extents of melting or heterogeneous mantle sources. We will combine bathymetry with results of analyses of lavas from the magma-rich segment and petrologic models

Geochemistry, geomorphology, and soil petrology of the Mars-like soils from Pampas de la Joya hyper-arid desert

NASA Astrophysics Data System (ADS)

Valdivia-Silva, Julio E.; Ortega-Gutierrez, Fernando; Bonaccorsi, Rosalba

2016-07-01

Mars-like environments on Earth are used as a model to guide the investigation of possible habitable Martian environments. In this work we evaluate and analyze the geology, geomorphology and soil petrology of the Pampas de La Joya Desert in southern Peru, in order to understand the processes that transformed the region into a Mars-like environment. Using a multidisciplinary approach, we analyze the different soils that compose the floor of the desert, as well as describe and interpret the post-Oligocene landscape emphasizing some Mars-like features with respect to its acting geologic processes, the habitability potential under very low levels of nutrients and water, and its suitability to sustain microorganisms or their remains. Importantly, this work is part of a bigger project that use Mars-like soils, looking for new crops capable to grow in extreme environments.

Petrology and Geochemistry of an Upper Crustal Mafic Complex- Hidden Lakes, Sierra Nevada Batholith, California

NASA Astrophysics Data System (ADS)

Lewis, M.; Bucholz, C. E.; Jagoutz, O. E.; Eddy, M. P.

2017-12-01

Magmatic differentiation in arc settings is likely a polybaric process, with crystallization of primitive basalts occurring primarily in the lower crust and more evolved melts in the upper crust. The general lack of mafic-ultramafic cumulates in the silicic paleo-arc upper crust supports this model. However, the Sierra Nevada Batholith preserves numerous mafic intrusions up to 25 km2, suggesting that significant volumes of mafic magma may differentiate at shallow crustal levels. Previous studies on several such intrusions report ages contemporaneous with Cretaceous batholith emplacement (Coleman et al., 1995), but only a few have investigated their chemistry and relationship to arc magmatism (Frost, 1987; Frost & Mahood, 1987; Sisson et al., 1996). We present field observations, petrography, mineral chemistry, and bulk rock compositional data for the Hidden Lakes Mafic Complex (HLMC), located in the Central Sierra Nevada Batholith. Preliminary CA-ID-TIMS U-Pb zircon ages constrain crystallization between 90 and 95 Ma, slightly older than the surrounding Cretaceous felsic plutons (89-90 Ma) and younger than adjacent Jurassic granodiorites (172 Ma). This 2.2 km2 complex consists of biotite+amphibole gabbros through qtz-monzonites, in gradational contact, and contains local pods of biotite- and amphibole-bearing olivine-orthopyroxenites and gabbronorites. Mineral compositions and field relations suggest that these lithologies were derived from a common crystallization sequence. The most primitive olivine-pyroxenite contains olivine and orthopyroxene in equilibrium with a melt with Mg# 54. Subsequent crystallization over a temperature range of 1025 to 700°C produced more evolved lithologies up to qtz-monzonites. Al-in-hornblende calculations for HLMC qtz-monzonites indicate a crystallization depth of 9-10 km, well into the upper crust. The early crystallization of amphibole requires a parental basalt with >6 wt% H2O, which may have enabled it to ascend into the upper

Status of Reconstruction of Fragmented Diamond-on-Silicon Collector From Genesis Spacecraft Solar Wind Concentrator

NASA Technical Reports Server (NTRS)

Rodriquez, Melissa C.; Calaway, M. C.; McNamara, K. M.; Hittle, J. D.

2009-01-01

In addition to passive solar wind collector surfaces, the Genesis Discovery Mission science canister had on board an electrostatic concave mirror for concentrating the solar wind ions, known as the concentrator . The 30-mm-radius collector focal point (the target) was comprised of 4 quadrants: two of single crystal SiC, one of polycrystalline 13C diamond and one of diamond-like-carbon (DLC) on a silicon substrate. [DLC-on-silicon is also sometimes referenced as Diamond-on-silicon, DOS.] Three of target quadrants survived the hard landing intact, but the DLC-on-silicon quadrant fractured into numerous pieces (Fig. 1). This abstract reports the status of identifying the DLC target fragments and reconstructing their original orientation.

Mineralogy, petrology, and trace element geochemistry of the Johnstown meteorite - A brecciated orthopyroxenite with siderophile and REE-rich components

NASA Technical Reports Server (NTRS)

Floran, R. J.; Prinz, M.; Hlava, P. F.; Keil, K.; Spettel, B.; Waenke, H.

1981-01-01

The compositional and petrologic characteristics of the Johnstown meteorite show it to contain uncontaminated and unbrecciated orthopyroxenite clasts of cumulative origin that (1) must have undergone subsolidus recrystalization, (2) are parental to the brecciated matrix, and (3) show no evidence of a xenolithic, meteoritic contribution to the matrix except for contamination by the projectile which crushed it on impact. The trapped liquid was not introduced in the impact process. The variability of such trace elements as the light rare earth elements, and the presence of plagioclase and olivine in only one of the thin sections studied, demonstrates the heterogeneity of coarse-grained diogenites on a millimeter scale and the difficulty of obtaining representative samples of such meteorites. The data presented indicate that this meteorite is a monominct breccia.

(U-Th-Sm)/He thermochronological age distribution in a slowly cooled plutonic complex (Ploumanac'h intrusion, France): insights into helium diffusion processes.

NASA Astrophysics Data System (ADS)

Recanati, A. C.; Gautheron, C.; Barbarand, J.; Tassan-Got, L.; Missenard, Y.; Pinna-Jamme, R.

2015-12-01

(U-Th-Sm)/He thermochronology is widely used to determine the thermal histories of mountain ranges and sedimentary basins. Apatite crystals retain helium at low temperatures, thus giving an insight into upper crustal evolution (e.g. exhumation, subsidence, erosion). Advanced models predict He production and diffusion rates in apatite crystals, thereby allowing determination of helium dates by integration over time/temperature paths (e.g. Gautheron et al., 2009). However, scattered dates and discordance between predicted and measured dates suggest that other parameters than time or temperature may also influence helium contents in apatite. The present study determines the variables that affect He diffusion in apatite over long timescales. We report the (U-Th-Sm)/He date distribution within a slowly cooled intrusion, along with AFT data, as well as extensive petrological and chemical characterization. The Ploumanac'h site (Brittany, France) was chosen because it includes small-scale spatial variations in petrology and chemistry (complex is composed of four different lithologies that underwent the same thermal history. A first cooling event occurred 250 Myrs ago, followed by a long stay in the He partial retention zone, and a final Late Cretaceous exhumation. Results evidence scattered (U-Th-Sm)/He dates, ranging from 80±8 to 250±25 Myrs, whereas AFT ages range from 120 to 160 ±10 Myrs. The old and scattered (U-Th-Sm)/He ages cannot be explained with current models. We investigate the influence of monograin chemistry, crystal defect, and sample petrology on (U-Th-Sm)/He dates. Data confirm that He can be stored at defect sites, but also support a decrease in He retentivity for high equivalent damage fraction (>6-9106 tracks/cm2). GAUTHERON C., TASSAN-GOT L., BARBARAND J., PAGEL M., 2009. Effect of alpha-damage annealing on apatite (U-Th)/He thermochronology. Chem. Geol. 266, 166-179.

Sex differences in cell genesis, hippocampal volume and behavioral outcomes in a rat model of neonatal HI

PubMed Central

Waddell, Jaylyn; Hanscom, Marie; Edwards, N. Shalon; McKenna, Mary C.; McCarthy, Margaret M.

2015-01-01

Hypoxia ischemia (HI) of the brain in near-term and term infants is a leading cause of infant mortality and lifelong disability but current therapeutic approaches remain limited. Males consistently display greater vulnerability to the deleterious consequences of HI in both humans and animal models. Neurogenesis increases after neonatal HI and offers a potential therapeutic target for recovery. The steroid hormone estradiol has been extensively explored as a neuroprotectant in adult models of stroke but with mixed results. Less consideration has been afforded to this naturally occurring agent in the developing brain, which has unique challenges from the adult. Using a model of term HI in the rat we have explored the impact of this insult on cell genesis in the hippocampus of males and females and the ability of estradiol treatment immediately after insult to restore function. Both short-term (3 days) and long-term (7 days) post-injury were assessed and revealed that only females had markedly increased cell genesis on the short-term but both sexes were increased long-term. A battery of behavioral tests revealed motor impairment in males and compromised episodic memory while both sexes were modestly impaired in spatial memory. Juvenile social play was also depressed in both sexes after HI. Estradiol therapy improved behavioral performance in both sexes but did not reverse a deficit in hippocampal volume ipsilateral to the insult. Thus the effects of estradiol do not appear to be via cell death or proliferation but rather involve other components of neural functioning. PMID:26376217

Sex differences in cell genesis, hippocampal volume and behavioral outcomes in a rat model of neonatal HI.

PubMed

Waddell, Jaylyn; Hanscom, Marie; Shalon Edwards, N; McKenna, Mary C; McCarthy, Margaret M

2016-01-01

Hypoxia-ischemia (HI) of the brain in near-term and term infants is a leading cause of infant mortality and lifelong disability but current therapeutic approaches remain limited. Males consistently display greater vulnerability to the deleterious consequences of HI in both humans and animal models. Neurogenesis increases after neonatal HI and offers a potential therapeutic target for recovery. The steroid hormone estradiol has been extensively explored as a neuroprotectant in adult models of stroke but with mixed results. Less consideration has been afforded to this naturally occurring agent in the developing brain, which has unique challenges from the adult. Using a model of term HI in the rat we have explored the impact of this insult on cell genesis in the hippocampus of males and females and the ability of estradiol treatment immediately after insult to restore function. Both short-term (3 days) and long-term (7 days) post-injury were assessed and revealed that only females had markedly increased cell genesis on the short-term but both sexes were increased long-term. A battery of behavioral tests revealed motor impairment in males and compromised episodic memory while both sexes were modestly impaired in spatial memory. Juvenile social play was also depressed in both sexes after HI. Estradiol therapy improved behavioral performance in both sexes but did not reverse a deficit in hippocampal volume ipsilateral to the insult. Thus the effects of estradiol do not appear to be via cell death or proliferation but rather involve other components of neural functioning. Published by Elsevier Inc.

Evidence for crustal recycling during the Archean: The parental magmas of the stillwater complex

NASA Technical Reports Server (NTRS)

Mccallum, I. S.

1988-01-01

The petrology and geochemistry of the Stillwater Complex, an Archean (2.7 Ga) layered mafic intrusion in the Beartooth Mountains of Montana is discussed. Efforts to reconstruct the compositions of possible parental magmas and thereby place some constraints on the composition and history of their mantle source regions was studied. A high-Mg andesite or boninite magma best matches the crystallization sequences and mineral compositions of Stillwater cumulates, and represents either a primary magma composition or a secondary magma formed, for example, by assimilation of crustal material by a very Mg-rich melt such as komatiite. Isotopic data do not support the extensive amounts of assimilation required by the komatiite parent hypothesis, and it is argued that the Stillwater magma was generated from a mantle source that had been enriched by recycling and homogenization of older crustal material over a large area.

Programmatically Optimized SEM Image Acquisition for Measurement of Contamination on Molybdenum Coated Foils from the NASA Genesis Mission

NASA Astrophysics Data System (ADS)

Gil, A.

2016-12-01

The NASA Genesis Mission flew high-purity collector materials on a satellite from 2001-2004 to collect a sample of the solar wind. Upon return to Earth, a spacecraft malfunction caused the onboard sample materials to be severely contaminated during the crash landing in the Utah desert. As part of an ongoing effort to decontaminate the collector materials, they are being scanned with a scanning electron microscope (SEM) to determine the amount of dirt and spacecraft debris contaminating the collectors. This effort is underway currently, but we have identified an opportunity to improve the quality of the SEM data collected. At present, many small images are acquired and stitched together to form larger images of Genesis collector pieces, which are then analyzed. The collectors are physically distorted, however, and the imaging method presently used doesn't allow imaging parameters to be adjusted between images to correct for this distortion. In order to improve the quality of the collected imaging, we are developing a program to acquire a focus map of each sample prior to image collection. The program then uses this data to adjust the position of the sample in the SEM to image all sections in focus and at a constant focal length. This is accomplished using the Python programming language, and the programmatic interface built into our Tescan VEGA Scanning Electron Microscope. Our approach, progress to date, and challenges are discussed.

Genesis of mud volcano fluids in the Gulf of Cadiz - A novel model approach

NASA Astrophysics Data System (ADS)

Schmidt, Christopher; Burwicz, Ewa; Hensen, Christian; Martínez-Loriente, Sara; Wallmann, Klaus; Gràcia, Eulàlia

2017-04-01

Mud volcanism and fluid seepage are common phenomena on the continental margin in the Gulf of Cadiz, North East Atlantic Ocean. Over the past 2 decades more than 50 mud volcanoes have been discovered and investigated interdisciplinarily. Mud volcano fluids emanating at these sites are sourced at great depths and migration is often mediated by strike slip faults in a seismically active region. The geochemical signals of the mud volcano fluids are affected by widespread various processes such as clay mineral dehydration, but also the recrystallization of ancient carbonate rocks and the alteration of oceanic crust have been suggested (Hensen et al., 2015). We developed a novel fully-coupled, basin-scale, reaction-transport model with an adaptive numerical mesh to simulate the fluid genesis in this region. An advantage of this model is the coupling of a realistic geophysical and geochemical approach, considering a growing sediment column over time together with instant compaction of sediments as well as diffusion and advection of dissolved pore water species and chemical reactions. In this proof of concept study, we looked at various scenarios to identify the processes of fluid genesis for 4 mud volcanoes, representing combinations in different subsurface settings. We can reproduce the fluid signatures (chloride, strontium, 87Sr/86Sr) of all mud volcanoes. Furthermore, we can give additional evidence that alteration of oceanic crust by fluid flow is a likely process affecting the fluid composition. Hensen, C., Scholz, F., Nuzzo, M., Valadares, V., Gràcia, E., Terrinha, P., Liebetrau, V., Kaul, N., Silva, S., Martínez-Loriente, S., Bartolome, R., Piñero, E., Magalhães, V. H., Schmidt, M., Weise, S. M., Cunha, M., Hilario, A., Perea, H., Rovelli, L., and Lackschewitz, K., 2015, Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea: Geology, v. 43, no. 4, p. 339-342.

Estimation of Water Within the Lithospheric Mantle of Central Tibet from Petrological-Geophysical Investigations

NASA Astrophysics Data System (ADS)

Vozar, J.; Fullea, J.; Jones, A. G.

2013-12-01

Investigations of the lithosphere and sub-lithospheric upper mantle by integrated petrological-geophysical modeling of magnetotelluric (MT) and seismic surface-wave data, which are differently sensitive to temperature and composition, allows us to reduce the uncertainties associated with modeling these two data sets independently, as commonly undertaken. We use selected INDEPTH MT data, which have appropriate dimensionality and large penetration depths, across central Tibet for 1D modeling. Our deep resistivity models from the data can be classified into two different and distinct groups: (i) the Lhasa Terrane and (ii) the Qiangtang Terrane. For the Lhasa Terrane group, the models show the existence of upper mantle conductive layer localized at depths of 200 km, whereas for the Qiangtang Terrane, this conductive layer is shallower at depths of 120 km. We perform the integrated geophysical-petrological modeling of the MT and surface-wave data using the software package LitMod. The program facilitates definition of realistic temperature and pressure distributions within the upper mantle for given thermal structure and oxide chemistry in the CFMAS system. This allows us to define a bulk geoelectric and seismic model of the upper mantle based on laboratory and xenolith data for the most relevant mantle minerals, and to compute synthetic geophysical observables. Our results suggest an 80-120 km-thick, dry lithosphere in the central part of the Qiangtang Terrane. In contrast, in the central Lhasa Terrane the predicted MT responses are too resistive for a dry lithosphere regardless its thickness; according to seismic and topography data the expected lithospheric thickness is about 200 km. The presence of small amounts of water significantly decreases the electrical resistivity of mantle rocks and is required to fit the MT responses. We test the hypothesis of small amounts of water (ppm scale) in the nominally anhydrous minerals of the lithospheric mantle. Such a small

Petrology of enstatite chondrites and anomalous enstatite achondrites

NASA Astrophysics Data System (ADS)

van Niekerk, Deon

2012-01-01

. The broad importance of these studies lies in documenting the petrology of extraterrestrial materials that reveal the geological history of the young solar system prior to the existence of planets. Furthermore, they serve to identify which mineral assemblages record nebular processes and which record processes on asteroids, so that future studies may select the correct material to address particular questions.

The Big Bang, Genesis, and Knocking on Heaven's Door

NASA Astrophysics Data System (ADS)

Gentry, Robert

2012-03-01

Michael Shermer recently upped the ante in the big bang-Genesis controversy by citing Lisa Randall's provocative claim (Science 334, 762 (2011)) that ``it is inconceivable that God could continue to intervene without introducing a material trace of his actions.'' So does Randall's and Shermer's agreement that no such evidence exists disprove God's existence? Not in my view because my 1970s Science, Nature and ARNS publications, and my article in the 1982 AAAS Western Division's Symposium Proceedings, Evolution Confronts Creation, all contain validation of God's existence via discovery of His Fingerprints of Creation and falsification of the big bang and geological evolution. These results came to wide public/scientific attention in my testimony at the 1981 Arkansas creation/evolution trial. There ACLU witness G Brent Dalrymple from the USGS -- and 2005 Medal of Science recipient from President Bush -- admitted I had discovered a tiny mystery (primordial polonium radiohalos) in granite rocks that indicated their almost instant creation. As a follow-up in 1992 and 1995 he sent out SOS letters to the entire AGU membership that the polonium halo evidence for fiat creation still existed and that someone needed to urgently find a naturalistic explanation for them. Is the physics community guilty of a Watergate-type cover-up of this discovery of God's existence and falsification of the big bang? For the answer see www.halos.tv.

Impact of global warming on tropical cyclone genesis in coupled and forced simulations: role of SST spatial anomalies

NASA Astrophysics Data System (ADS)

Royer, Jean-François; Chauvin, Fabrice; Daloz, Anne-Sophie

2010-05-01

The response of tropical cyclones (TC) activity to global warming has not yet reached a clear consensus in the Fourth Assessment Report (AR4) published by the Intergovernmental Panel on Climate Change (IPCC, 2007) or in the recent scientific literature. Observed series are neither long nor reliable enough for a statistically significant detection and attribution of past TC trends, and coupled climate models give widely divergent results for the future evolution of TC activity in the different ocean basins. The potential importance of the spatial structure of the future SST warming has been pointed out by Chauvin et al. (2006) in simulations performed at CNRM with the ARPEGE-Climat GCM. The current presentation describes a new set of simulations that have been performed with the ARPEGE-Climat model to try to understand the possible role of SST patterns in the TC cyclogenesis response in 15 CMIP3 coupled simulations analysed by Royer et al (2009). The new simulations have been performed with the atmospheric component of the ARPEGE-Climat GCM forced in 10 year simulations by the SST patterns from each of 15 CMIP3 simulations with different climate model at the end of the 21st century according to scenario A2. The TC analysis is based on the computation of a Convective Yearly Genesis Parameter (CYGP) and the Genesis Potential Index (GPI). The computed genesis indices for each of the ARPEGE-Climat forced simulations is compared with the indices computed directly from the initial coupled simulation. The influence of SST patterns can then be more easily assessed since all the ARPEGE-Climat simulations are performed with the same atmospheric model, whereas the original simulations used models with different parameterization and resolutions. The analysis shows that CYGP or GPI anomalies obtained with ARPEGE are as variable between each other as those obtained originally by the different IPCC models. The variety of SST patterns used to force ARPEGE explains a large part of

Geochemistry and petrology of basaltic rocks from the Marshall Islands

USGS Publications Warehouse

Davis, Alice S.; Schwab, William C.; Haggerty, Janet A.

1986-01-01

A variety of volcanic rock was recovered from the flanks of seamounts, guyots, atolls, and islands in the Ratak chain of the Marshall Islands on the U.S. Geological Survey cruise L9-84-CP. The main objective of this cruise was to study the distribution and composition of ferromanganese oxide crusts. Preliminary results of managanese crust composition are reported by Schwab et al. (1985) and detailed studies are in preparation (Schwab et al., 1986). A total of seven seafloor edifices were studied using 12 khz, 3.5 khz and air gun seismic reflection, chain dredge and box corer. Bathymetry and ship track lines are presented by Schwab and Bailey (1985). Of the seven edifices surveyed two support atolls (Majuro and Taongi) and one is a tiny island (Jemo). Dredge locations and water depths are given in Table 1 and dredge locations are shown in Figure 1. Due to equipment failures depths of dredge hauls were limited to shallow depth for all except the first two sites occupied. Recovery consisted mostly of young, poorly-consolidated limestone of fore-reef slope deposit and minor volcanogenic breccia and loose talus. The breccia and pieces of talus are thickly encrusted with ferromanganese oxide, whereas the young limestone is only coated by a thin layer. Four of the seven sites surveyed yielded volcanic rock. The volcanic rock, volumetrically a minor part of each dredge haul, consists mostly of lapilli and cobble-size clasts in a calcareous matrix or as loose talus. Most clasts show evidence of reworking, being sub- to well rounded, sometimes with a thin ferromanganese crust of their own. This paper reports preliminary findings on the petrology and geochemistry of volcanic rock recovered.

Petrologic constraints on the decompression history of magma prior to Vulcanian explosions at the Soufrière Hills volcano, Montserrat

NASA Astrophysics Data System (ADS)

Clarke, A. B.; Stephens, S.; Teasdale, R.; Sparks, R. S. J.; Diller, K.

2007-04-01

A series of 88 Vulcanian explosions occurred at the Soufrière Hills volcano, Montserrat, between August and October, 1997. Conduit conditions conducive to creating these and other Vulcanian explosions were explored via analysis of eruptive products and one-dimensional numerical modeling of magma ascent through a cylindrical conduit. The number densities and textures of plagioclase microlites were documented for twenty-three samples from the events. The natural samples all show very high number densities of microlites, and > 50% by number of microlites have areas < 20 μm 2. Pre-explosion conduit conditions and decompression history have been inferred from these data by comparison with experimental decompressions of similar groundmass compositions. Our comparisons suggest quench pressures < 30 MPa (origin depths < 2 km) and multiple rapid decompressions of > 13.75 MPa each during ascent from chamber to surface. Values are consistent with field studies of the same events and statistical analysis of explosion time-series data. The microlite volume number density trend with depth reveals an apparent transition from growth-dominated crystallization to nucleation-dominated crystallization at pressures of ˜ 7 MPa and lower. A concurrent sharp increase in bulk density marks the onset of significant open-system degassing, apparently due to a large increase in system permeability above ˜ 70% vesicularity. This open-system degassing results in a dense plug which eventually seals the conduit and forms conditions favorable to Vulcanian explosions. The corresponding inferred depth of overpressure at 250-700 m, near the base of the dense plug, is consistent with depth to center of pressure estimated from deformation measurements. Here we also illustrate that one-dimensional models representing ascent of a degassing, crystal-rich magma are broadly consistent with conduit profiles constructed via our petrologic analysis. The comparison between models and petrologic data suggests

Paleoproterozoic multistage metamorphic events in Jining metapelitic rocks from the Khondalite Belt in the North China Craton: Evidence from petrology, phase equilibria modelling and U-Pb geochronology

NASA Astrophysics Data System (ADS)

Cai, Jia; Liu, Fulai; Liu, Pinghua

2017-05-01

Metapelitic rocks of the Jining Complex (sillimanite-cordierite-garnet (Sil-Crd-Grt) gneisses, sillimanite-garnet (Sil-Grt) gneisses and quartzofeldspathic rocks) are exposed in the eastern segment of the Khondalite Belt (KB) in the North China Craton (NCC). The Sil-Crd-Grt gneisses have preserved polyphase mineral assemblages and microstructural evidence of anatexis, resulting from biotite dehydration melting. Petrological observations revealed that the Sil-Crd-Grt gneisses contain three metamorphic assemblages: a peak assemblage of garnet porphyroblast and matrix biotite + sillimanite + K-feldspar + plagioclase + quartz + ilmenite + magnetite, a post-peak near-isothermal decompressional assemblage of garnet + cordierite + biotite + sillimanite + K-feldspar + plagioclase + quartz + ilmenite + magnetite, and a decompressional cooling assemblage of garnet + biotite + cordierite + K-feldspar + plagioclase + quartz + ilmenite + magnetite. A clockwise P-T path was defined involving the inferred peak stage followed by post-peak near-isothermal decompression and decompressional cooling stages, with P-T conditions of 790-825 °C and 9-10 kbar, 810-890 °C and 6.0-6.5 kbar, and 780-810 °C and 4.0-5.5 kbar, respectively. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) U-Pb analyses of the Sil-Crd-Grt gneisses and Sil-Grt gneisses for the detrital and metamorphic zircons yielded a protolith age of ∼2.0 Ga and the late Paleoproterozoic metamorphic age of 1895-1885 Ma. The results reveal that the metapelitic rocks of the Jining Complex underwent continent-continent subduction or collision in the peak metamorphic stage, followed by a post-collisional exhumation event in the post-peak decompressional stage, and a subsequent decompressional cooling stage between the Yinshan and Ordos blocks to form the Paleoproterozoic KB.

Complex zoning behavior in pyroxene in FeO-rich chondrules in the Semarkona ordinary chondrite

NASA Technical Reports Server (NTRS)

Jones, Rhian H.; Papike, J. J.

1993-01-01

A detailed understanding of the properties of silicate minerals in chondrules is essential to the interpretation of chondrule formation conditions. This study is further work in a series of petrologic studies of chondrules in the least equilibrated LL chondrite, Semarkona (LL3.0). The objectives of this work are as follows: (1) to understand chondrule formation conditions and nebular processes; and (2) to use the data as a basis for understanding the effects of metamorphism in more equilibrated chondrites. FeO-rich pyroxene in the chondrules described shows complex zoning behavior. Low-Ca clinopyroxene, orthopyroxene, pigeonite, and augite are all observed, in various associations with one another. Coexisting olivine phenocrysts are also FeO-rich and strongly zoned. Compositional and zoning properties are similar to those observed in boninites and are interpreted as resulting from rapid cooling of individual chondrules.

Geological and petrological considerations relevant to the disposal of radioactive wastes by hydraulic fracturing: an example at the US Department of Energy's Oak Ridge National Laboratory

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

Haase, C.S.

1983-01-01

At Oak Ridge National Laboratory the Pumpkin Valley Shale is used as a host formation for hydraulic fracturing waste disposal. Determination of the relationships between the distribution of different lithologies and porosity-permeability trends within this host formation allows these properties, important to hydraulic fracturing operations, to be related to measurable and mappable geological and petrological parameters. It also permits extrapolation of such patterns to little-studied portions of the Pumpkin Valley Shale. Such knowledge better allows for the satisfactory operation and assessment of the hydraulic fracturing at Oak Ridge National Laboratory.

Petrology and Raman Spectroscopy of Shocked Phases in the Gujba CB Chondrite and the Shock History of the CB Parent Body

NASA Technical Reports Server (NTRS)

Weisberg, M. K.; Kimura, M.

2004-01-01

The CB chondrites are metal-rich chondritic meteorites having characteristics that sharply distinguish them from other chondrites [1], including (1) high metal abundances (60-80 vol.% metal), (2) most chondrules have cryptocrystalline or barred textures, (3) moderately volatile lithophile elements are highly depleted and (4) nitrogen is enriched in the heavy isotope. Similarities in mineral composition, as well as oxygen and nitrogen isotopic compositions of the CB to CR and CH chondrites are consistent with derivation of these chondrite groups from a common nebular reservoir, hence their grouping in the CR clan [1, 2, 3, 4]. CB chondrites have been divided into CBa (Gujba, Bencubbin, Weatherford) and CBb (Hammadah al Hamra 237 and QUE 94411) subgroups based on petrologic characteristics.

Columnar travertines: bio-influenced genesis, Porcelana Geysers, Northern Patagonia, Chile

NASA Astrophysics Data System (ADS)

Ruiz, B. S.; Morata, D.; Díez, B.; Daniele, L.

2017-12-01

Porcelana Geysers are located on the slopes of Barranco Colorado volcano, southern Chile, and is characterized by having a lateral hydrothermal fluid transport and an important CO2 content, having high gas exsolution rates on the surface at temperatures above 80°C. But it does not seem to be enough to explain the genesis of columnar travertines more than 3 meters high, considering that precipitation rates counteracts erosive rates due to rainy climate of the zone and the high slope gradient (>10 mm/h). The presence of extremophilic microbial diversity could explain this exceptional travertine morphology, particularly Phyla Cyanobacteria, Bacteroidetes and Order Thermales, which is evidenced by the vast visible presence of extracellular polymeric substances (EPS), reducing conditions in hot springs waters, microscopic and macroscopic textures and isotopic compositions of travertines, which are lower than the values that thermogenic travertines usually present (δ13C values from -4.85‰ to -3.37‰). These biotic processes would increase total dissolved gas pressure and [CO2]AQ values (over 0.05 mmol/L), and hence making the hydrostatic and bubbling pressure lower in the geysers vent fluids, which increases the amount of bubbles and their size and precipitation total rate of calcium carbonate (about 0.003 mm/h)

Field occurrences and petrology of eclogites from the Dabie Mountains, Anhui, central China

NASA Astrophysics Data System (ADS)

Wang, X.; Jing, Y.; Liou, J. G.; Pan, G.; Liang, W.; Xia, M.; Maruyama, S.

1990-11-01

Four distinct types of eclogites are recognized according to their field occurrences and mineral parageneses in a gneiss terrane of the Dabie Mountains, a collision zone between the Sino-Korean and Yangtze cratons in central China. Some eclogites contain coesite and its quartz pseudomorphs enclosed in garnet and omphacite. Type I eclogites occur as layers in serpentinites and contain garnet, clinopyroxene, orthopyroxene, phengite, rutile, and coesite pseudomorph. Type II eclogites occur as lenticular bodies inside serpentinites and contain garnet, clinopyroxene, quartz, rutile, and edenitic hornblende. Type III eclogites occur as blocks of 2 cm to 20 m in size in a matrix of hornblende gneiss and biotite gneiss, and Type IV eclogites occur as thin layers interbedded with amphibolites. P- T estimates for these different eclogites indicate that they were formed under different physical conditions. All the eclogites were affected by later regional metamorphism for which the P- T conditions are estimated. This paper provides an introduction to the abundant eclogites from central China which have not been reported previously in Western literature. Specifically, the mode of field occurrence, petrography, mineral chemistry and formation conditions of the four types of eclogites are described. The paper is thus designed to establish a petrological framework for future detailed studies of the eclogites and their country rocks in an ancient zone of collision.

Petrologic and chemical changes in ductile shear zones as a function of depth in the continental crust

NASA Astrophysics Data System (ADS)

Yang, Xin-Yue

Petrologic and geochemical changes in ductile shear zones are important for understanding deformational and geochemical processes of the continental crust. This study examines three shear zones that formed under conditions varying from lower greenschist facies to upper amphibolite facies in order to document the petrologic and geochemical changes of deformed rocks at various metamorphic grades. The studied shear zones include two greenschist facies shear zones in the southern Appalachians and an upper amphibolite facies shear zone in southern Ontario. The mylonitic gneisses and mylonites in the Roses Mill shear zone of central Virginia are derived from a ferrodiorite protolith and characterized by a lower greenschist facies mineral assemblage. Both pressure solution and recrystallization were operative deformation mechanisms during mylonitization in this shear zone. Strain-driven dissolution and solution transfer played an important role in the mobilization of felsic components (Si, Al, K, Na, and Ca). During mylonitization, 17% to 32% bulk rock volume losses of mylonites are mainly attributed to removal of these mobile felsic components by a fluid phase. Mafic components (Fe, Mg, Ti, Mn and P) and trace elements, REE, Y, V and Sc, were immobile. At Rosman, North Carolina, the Brevard shear zone (BSZ) shows a deformational transition from the coarse-grained Henderson augen gneiss (HAG) to proto-mylonite, mylonite and ultra-mylonite. The mylonites contain a retrograde mineral assemblage as a product of fluid-assisted chemical breakdown of K-feldspar and biotite at higher greenschist facies conditions. Recrystallization and intra-crystalline plastic deformation are major deformation mechanisms in the BSZ. Fluid-assisted mylonitization in the BSZ led to 6% to 23% bulk volume losses in mylonites. During mylonitization, both major felsic and mafic elements and trace elements, Rb, Sr, Zr, V, Sc, and LREE were mobile; however, the HREEs were likely immobile. A shear zone

Subduction metamorphism in the Himalayan ultrahigh-pressure Tso Morari massif: An integrated geodynamic and petrological modelling approach

NASA Astrophysics Data System (ADS)

Palin, Richard M.; Reuber, Georg S.; White, Richard W.; Kaus, Boris J. P.; Weller, Owen M.

2017-06-01

The Tso Morari massif is one of only two regions where ultrahigh-pressure (UHP) metamorphism of subducted crust has been documented in the Himalayan Range. The tectonic evolution of the massif is enigmatic, as reported pressure estimates for peak metamorphism vary from ∼2.4 GPa to ∼4.8 GPa. This uncertainty is problematic for constructing large-scale numerical models of the early stages of India-Asia collision. To address this, we provide new constraints on the tectonothermal evolution of the massif via a combined geodynamic and petrological forward-modelling approach. A prograde-to-peak pressure-temperature-time (P-T-t) path has been derived from thermomechanical simulations tailored for Eocene subduction in the northwestern Himalaya. Phase equilibrium modelling performed along this P-T path has described the petrological evolution of felsic and mafic components of the massif crust, and shows that differences in their fluid contents would have controlled the degree of metamorphic phase transformation in each during subduction. Our model predicts that peak P-T conditions of ∼2.6-2.8 GPa and ∼600-620 ∘C, representative of 90-100 km depth (assuming lithostatic pressure), could have been reached just ∼3 Myr after the onset of subduction of continental crust. This P-T path and subduction duration correlate well with constraints reported for similar UHP eclogite in the Kaghan Valley, Pakistan Himalaya, suggesting that the northwest Himalaya contains dismembered remnants of what may have been a ∼400-km-long UHP terrane comparable in size to the Western Gneiss Region, Norway, and the Dabie-Sulu belt, China. A maximum overpressure of ∼0.5 GPa was calculated in our simulations for a homogeneous crust, although small-scale mechanical heterogeneities may produce overpressures that are larger in magnitude. Nonetheless, the extremely high pressures for peak metamorphism reported by some workers (up to 4.8 GPa) are unreliable owing to conventional thermobarometry

Petrological evidence for non-linear increase of magmatic intrusion rates before eruption at open vent mafic volcanoe

NASA Astrophysics Data System (ADS)

Ruth, D. C. S.; Costa Rodriguez, F.

2015-12-01

The most active volcanoes on earth erupt in a yearly to decadal time scales, typically erupt mafic magmas and are open-vent systems with prominent degassing plumes (e.g. Mayon, Arenal, Llaima, Etna). Here we investigate the plumbing systems, dynamics, and processes that drive eruptions at these systems. These are key questions for improving hazard evaluation, and better understanding the unrest associated with these types of volcanoes. The petrology and geochemistry from six historical eruptions (1947-2006) of Mayon volcano (Philippines) shows that all lavas are basaltic andesite with phenocrysts of plagioclase + orthopyroxene (Opx) + clinopyroxene. Opx crystals show a variety of compositions and zoning patterns (reverse, normal or complex) with Mg# (= 100 *Mg/[Mg+Fe]) varying from 67 to 81. The simplest interpretation is that the low Mg# parts of the crystals resided on an upper crustal and crystal rich reservoir that was intruded by more primitive magmas from which the high Mg# parts of the crystals grew. Modelling Mg-Fe diffusion in Opx shows that times since magma injection and eruption range from a few days up to 3.5 years in all of the investigated eruptions. The longest diffusion times are shorter than the repose times between the eruptions, which implies that crystal recycling between eruptive events is negligible. This is a surprising result that shows that for each eruption a different part of the evolved crystal-rich plumbing system is activated. This can be due to random intrusion location or an irreversibility of the plumbing system that prevents multiple eruptions from the same crystal-rich part. Moreover, we find that the number of intrusions markedly increases before each eruption in a non-linear manner. Such an increased rate of intrusions with time might reflect non-linear rheological properties of the crystal-rich system, of the enclosing rocks, or the non-linear evolution of crystal-melt reaction-dissolution fronts during magma intrusions.

Petrology and mineral chemistry of peraluminous Marziyan granites, Sanandaj-Sirjan metamorphic belt (NW Iran)

NASA Astrophysics Data System (ADS)

Darvishi, Esmaiel; Khalili, Mahmoud; Beavers, Roy; Sayari, Mohammad

2015-10-01

The Marziyan granites are located in the north of Azna and crop out in the Sanandaj-Sirjan metamorphic belt. These rocks contain minerals such as quartz, K-feldspars, plagioclase, biotite, muscovite, garnet, tourmaline and minor sillimanite. The mineral chemistry of biotite indicates Fe-rich (siderophyllite), low TiO2, high Al2O3, and low MgO nature, suggesting considerable Al concentration in the source magma. These biotites crystallized from peraluminous S-type granite magma belonging to the ilmenite series. The white mica is rich in alumina and has muscovite composition. The peraluminous nature of these rocks is manifested by their remarkably high SiO2, Al2O3 and high molar A/CNK (> 1.1) ratio. The latter feature is reflected by the presence of garnet and muscovite. All field observations, petrography, mineral chemistry and petrology evidence indicate a peraluminous, S-type nature of the Marziyan granitic rocks that formed by partial melting of metapelite rocks in the mid to upper crust possibly under vapour-absent conditions. These rocks display geochemical characteristics that span the medium to high-K and calc-alkaline nature and profound chemical features typical of syn-collisional magmatism during collision of the Afro-Arabian continental plate and the Central Iranian microplate.

Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

USGS Publications Warehouse

Belkin, H.E.; Tewalt, S.J.; Hower, J.C.; Stucker, J.D.; O'Keefe, J.M.K.

2009-01-01

Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1??wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential.

The genomic complexity of primary human prostate cancer

PubMed Central

Berger, Michael F.; Lawrence, Michael S.; Demichelis, Francesca; Drier, Yotam; Cibulskis, Kristian; Sivachenko, Andrey Y.; Sboner, Andrea; Esgueva, Raquel; Pflueger, Dorothee; Sougnez, Carrie; Onofrio, Robert; Carter, Scott L.; Park, Kyung; Habegger, Lukas; Ambrogio, Lauren; Fennell, Timothy; Parkin, Melissa; Saksena, Gordon; Voet, Douglas; Ramos, Alex H.; Pugh, Trevor J.; Wilkinson, Jane; Fisher, Sheila; Winckler, Wendy; Mahan, Scott; Ardlie, Kristin; Baldwin, Jennifer; Simons, Jonathan W.; Kitabayashi, Naoki; MacDonald, Theresa Y.; Kantoff, Philip W.; Chin, Lynda; Gabriel, Stacey B.; Gerstein, Mark B.; Golub, Todd R.; Meyerson, Matthew; Tewari, Ashutosh; Lander, Eric S.; Getz, Gad; Rubin, Mark A.; Garraway, Levi A.

2010-01-01

Prostate cancer is the second most common cause of male cancer deaths in the United States. Here we present the complete sequence of seven primary prostate cancers and their paired normal counterparts. Several tumors contained complex chains of balanced rearrangements that occurred within or adjacent to known cancer genes. Rearrangement breakpoints were enriched near open chromatin, androgen receptor and ERG DNA binding sites in the setting of the ETS gene fusion TMPRSS2-ERG, but inversely correlated with these regions in tumors lacking ETS fusions. This observation suggests a link between chromatin or transcriptional regulation and the genesis of genomic aberrations. Three tumors contained rearrangements that disrupted CADM2, and four harbored events disrupting either PTEN (unbalanced events), a prostate tumor suppressor, or MAGI2 (balanced events), a PTEN interacting protein not previously implicated in prostate tumorigenesis. Thus, genomic rearrangements may arise from transcriptional or chromatin aberrancies to engage prostate tumorigenic mechanisms. PMID:21307934

Risk Modeling of Interdependent Complex Systems of Systems: Theory and Practice.

PubMed

Haimes, Yacov Y

2018-01-01

The emergence of the complexity characterizing our systems of systems (SoS) requires a reevaluation of the way we model, assess, manage, communicate, and analyze the risk thereto. Current models for risk analysis of emergent complex SoS are insufficient because too often they rely on the same risk functions and models used for single systems. These models commonly fail to incorporate the complexity derived from the networks of interdependencies and interconnectedness (I-I) characterizing SoS. There is a need to reevaluate currently practiced risk analysis to respond to this reality by examining, and thus comprehending, what makes emergent SoS complex. The key to evaluating the risk to SoS lies in understanding the genesis of characterizing I-I of systems manifested through shared states and other essential entities within and among the systems that constitute SoS. The term "essential entities" includes shared decisions, resources, functions, policies, decisionmakers, stakeholders, organizational setups, and others. This undertaking can be accomplished by building on state-space theory, which is fundamental to systems engineering and process control. This article presents a theoretical and analytical framework for modeling the risk to SoS with two case studies performed with the MITRE Corporation and demonstrates the pivotal contributions made by shared states and other essential entities to modeling and analysis of the risk to complex SoS. A third case study highlights the multifarious representations of SoS, which require harmonizing the risk analysis process currently applied to single systems when applied to complex SoS. © 2017 Society for Risk Analysis.

Using Zebrafish to Study Podocyte Genesis During Kidney Development and Regeneration

PubMed Central

Kroeger, Paul T.; Wingert, Rebecca A.

2014-01-01

SUMMARY During development, vertebrates form a progression of up to three different kidneys that are comprised of functional units termed nephrons. Nephron composition is highly conserved across species, and an increasing appreciation of the similarities between zebrafish and mammalian nephron cell types has positioned the zebrafish as a relevant genetic system for nephrogenesis studies. A key component of the nephron blood filter is a specialized epithelial cell known as the podocyte. Podocyte research is of the utmost importance as a vast majority of renal diseases initiate with the dysfunction or loss of podocytes, resulting in a condition known as proteinuria that causes nephron degeneration and eventually leads to kidney failure. Understanding how podocytes develop during organogenesis may elucidate new ways to promote nephron health by stimulating podocyte replacement in kidney disease patients. In this review, we discuss how the zebrafish model can be used to study kidney development, and how zebrafish research has provided new insights into podocyte lineage specification and differentiation. Further, we discuss the recent discovery of podocyte regeneration in adult zebrafish, and explore how continued basic research using zebrafish can provide important knowledge about podocyte genesis in embryonic and adult environments. PMID:24920186

Characteristics and genesis of Rare Earth Element (REE) in western Indonesia

NASA Astrophysics Data System (ADS)

Handoko, A. D.; Sanjaya, E.

2018-02-01

Rare Earth Element (REE) has unique properties that have been used in many hightech applications. The demand of REE increased recently in the world due to its special properties. Although REE concentration in the crust is higher than gold, economically viable deposits are still rare. Reduction of REE exports by China cause increased prices of REE. Due to this condition, exploration of potential REE mines emerged. Indonesia also participates in this phenomenon, and explore the possibility of REE mines in its area. This review will discuss the characteristics and genesis of REE and its occurrence in western Indonesia; focused in Sumatera, Tin Island, and Kalimantan. The review is done based on literature research from several resources about characteristics of rare earth element in general and in the given area. The research shows that the potential REE mines can be found in several different locations in Indonesia, such as Tin Island, Sumatera, and Kalimantan. Most of them are composed of monazite, zircon, and xenotime as rare earth minerals. Monazite iss known for its elevated number of radioactive elements, so study about radioactive content and more environment friendly ore processing becomes compulsory.

Genesis of Pre-Hurricane Felix (2007). Part 2; Warm Core Formation, Precipitation Evolution, and Predictability

NASA Technical Reports Server (NTRS)

Wang, zhuo; Montgomery M. T.; Dunkerton, T. J.

2010-01-01

This is the second of a two-part study examining the simulated formation of Atlantic Hurricane Felix (2007) in a cloud-representing framework. Here several open issues are addressed concerning the formation of the storm's warm core, the evolution and respective contribution of stratiform versus convective precipitation within the parent wave's pouch, and the sensitivity of the development pathway reported in Part I to different model physics options and initial conditions. All but one of the experiments include ice microphysics as represented by one of several parameterizations, and the partition of convective versus stratiform precipitation is accomplished using a standard numerical technique based on the high-resolution control experiment. The transition to a warm-core tropical cyclone from an initially cold-core, lower tropospheric wave disturbance is analyzed first. As part of this transformation process, it is shown that deep moist convection is sustained near the pouch center. Both convective and stratiform precipitation rates increase with time. While stratiform precipitation occupies a larger area even at the tropical storm stage, deep moist convection makes a comparable contribution to the total rain rate at the pregenesis stage, and a larger contribution than stratiform processes at the storm stage. The convergence profile averaged near the pouch center is found to become dominantly convective with increasing deep moist convective activity there. Low-level convergence forced by interior diabatic heating plays a key role in forming and intensifying the near-surface closed circulation, while the midlevel convergence associated with stratiform precipitation helps to increase the midlevel circulation and thereby contributes to the formation and upward extension of a tropospheric-deep cyclonic vortex. Sensitivity tests with different model physics options and initial conditions demonstrate a similar pregenesis evolution. These tests suggest that the genesis

Dispersion and waves in bounded plasmas with subwavelength inhomogeneities: Genesis of MEFIB

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

Bhattacharjee, Sudeep

Bounded plasma exhibit many interesting behavior that are not found in plasmas of 'infinite' extent such as space and astrophysical plasmas. Our studies have revealed that the dispersion properties of waves in a bounded magnetoplasma deviates considerably from the predictions of the Clemmow-Mullaly-Allis (CMA) model, giving rise to new regimes of wave propagation and absorption. The anisotropy of the medium dictated by the length scales of plasma nonuniformity and magnetostatic field inhomogeneity lead to rotation of the polarization axis an effect similar to the Cotton-Mouton effect in a magneto-optic medium but with distinct differences due to wave induced resonances. Thismore » article highlights some of these interesting effects observed experimentally and corroborated with Monte Carlo simulations. One of the principal outcomes of this research is the genesis of a novel multielement focused ion beam (MEFIB) system that utilizes compact bounded plasmas in a minimum – B field to provide intense focused ion beams of a variety of elements for new research in nanoscience and technology.« less

Relationships Among Intrinsic Properties of Ordinary Chondrites: Oxidation State, Bulk Chemistry, Oxygen-isotopic Composition, Petrologic Type, and Chondrule Size

NASA Technical Reports Server (NTRS)

Rubin, Alan E.

2006-01-01

The properties of ordinary chondrites (OC) reflect both nebular and asteroidal processes. OC are modeled here as having acquired nebular water, probably contained within phyllosilicates, during agglomeration. This component had high Ai70 and acted like an oxidizing agent during thermal metamorphism. The nebular origin of this component is consistent with negative correlations in H, L, and LL chondrites between oxidation state (represented by olivine Fa) and bulk concentration ratios of elements involved in the metal-silicate fractionation (e.g., NdSi, Ir/Si, Ir/Mn, Ir/Cr, Ir/Mg, Ni/Mg, As/Mg, Ga/Mg). LL chondrites acquired the greatest abundance of phyllosilicates with high (delta)O-17 among OC (and thus became the most oxidized group and the one with the heaviest O isotopes); H chondrites acquired the lowest abundance, becoming the most reduced OC group with the lightest O isotopes. Chondrule precursors may have grown larger and more ferroan with time in each OC agglomeration zone. Nebular turbulence may have controlled the sizes of chondrule precursors. H-chondrite chondrules (which are the smallest among OC) formed from the smallest precursors. In each OC region, low-FeO chondrules formed before high-FeO chondrules during repeated episodes of chondrule formation. During thermal metamorphism, phyllosilicates were dehydrated; the liberated water oxidized metallic Fe-Ni. This caused correlated changes with petrologic type including decreases in the modal abundance of metal, increases in olivine Fa and low-Ca pyroxene Fs, increases in the olivine/pyroxene ratio, and increases in the kamacite Co and Ni contents. As water (with its heavy 0 isotopes) was lost during metamorphism, inverse correlations between bulk (delta)O-18 and bulk (delta)O-17 with petrologic type were produced. The H5 chondrites that were ejected from their parent body approx.7.5 Ma ago during a major impact event probably had been within a few kilometers of each other since they accreted approx.4

Tectonic overpressure may reconcile the structural and petrological records of the Adula nappe (Central Alps)

NASA Astrophysics Data System (ADS)

Pleuger, Jan; Podladchikov, Yuri

2014-05-01

The Penninic Alps are the result of progressive underthrusting of oceanic and continental domains below the Adriatic microplate. Situated in the internal part of the Alpine orogen, they expose basement and thinned cover nappes which have been metamorphosed to variable degree, among them several units which were subjected to ultrahigh-pressure metamorphism. Due to the more or less strong nappe-internal deformation of these units, cross sections through the Penninic Alps cannot be restored kinematically by area or line balancing techniques. Instead, such restorations attempt to consistently reconcile geochronological and structural data and petrological pressure-temperature estimates. Pressure data are usually converted into depth assuming that they were lithostatic which puts the ultrahigh-pressure units to subcrustal depths. Tectonic exhumation of a unit from such a depth by whatever mechanism requires a large-scale normal fault with several tens of kilometres of displacement in the hanging wall of the unit. However, for all Penninic ultrahigh-pressure units (Dora Maira unit, Zermatt-Saas zone, Monviso unit, Adula-Cima Lunga nappe), the oldest mappable post-peak-pressure structures are related to top-to-the-foreland shearing, i.e. thrusting. There are two potential solutions to this dilemma. The first one is that either the exhumation was indeed accommodated by a large-scale normal fault which became completely overprinted during later deformational stages. The other one is that peak pressures were not lithostatic. To our knowledge, the first solution is applied to all kinematic models of the Alps so far. In order to explore the feasibility of the second solution, we performed a purely structural restoration of the NFP20-East cross section without lithostatic pressure-to-depth-conversions. This cross-section comprises the ultrahigh-pressure Adula nappe (up to ca. 30 kbar) and relies on quantitative strain data from the overlying units. The result shows that, in

Beyond the hypothesis: Theory's role in the genesis, opposition, and pursuit of the Higgs boson

NASA Astrophysics Data System (ADS)

Wells, James D.

2018-05-01

The centrally recognized theoretical achievement that enabled the Higgs boson discovery in 2012 was the hypothesis of its existence, made by Peter Higgs in 1964. Nevertheless, there is a significant body of comparably important theoretical work prior to and after the Higgs boson hypothesis. In this article we present an additional perspective of how crucial theory work was to the genesis of the Higgs boson hypothesis, especially emphasizing its roots in Landau's theory of phase transitions and subsequent theoretical work on superconductivity. A detailed description is then given of the opposition to the Higgs boson hypothesis by many researchers, giving evidence to its speculative nature. And finally, it is discussed the importance of theory work in the decades after the hypothesis in order to make possible the experimental discovery of the Higgs boson.

Les granitoïdes néoprotérozoïques de Khzama, Anti-Atlas central, Maroc: marqueurs de l'évolution d'un magmatisme d'arc à un magmatisme alcalineNeoproterozoic granitoids from Khzama, central Anti-Atlas, Morocco: evolution markers from arc magmatism to alkaline magmatism

NASA Astrophysics Data System (ADS)

El-Khanchaoui, T.; Lahmam, M.; El-Boukhari, A.; El-Beraaouz, H.

2001-05-01

Petrological study and zircon typology provide important information that is related to the classification and genesis of Neoproterozoic granitoids in the Khzama area (northeast Siroua). The Pan-African granitoids show a transition from island-arc magmatism to alkaline magmatism. A space and time zonation of magmatism from the north to the south is evident. Early Pan-African granitoids were generated from various magma sources through different petrogenetic mechanisms. The first association corresponds to the low-K calc-alkaline plutons of Ait Nebdas, the second one correponds to high-K calc-alkaline post-collisional granites (Tamassirte-Tiferatine and Ifouachguel). Finally, shoshonitic magmatism (Irhiri) ends the magmatic evolution of the region. Thus, the late Pan-African granitic plutonism began with calc-alkaline associations and ended with K-alkaline magmatism in a transtensional setting, heralding the onset of the Moroccan Palæozoic cycle.

Petrology and stratigraphy of Paleogene nonmarine sandstones, Cascade Range, Washington

USGS Publications Warehouse

Frizzell, Virgil A.

1979-01-01

The Cascade Range of Washington north of 47? latitude is composed of probable Paleozoic and Mesozoic metamorphic rocks and Mesozoic and Tertiary plutonic rocks. Several Paleogene nonmarine arkosic sandstone units fringe and in part occur within the complex crystalline core. The early to middle Eocene Chuckanut Formation is present on the west side of the crystalline core in the western foothills of the Cascades. The early to middle Eocene Swauk Formation partially encircles the Mt. Stuart massif of the central Cascades. In the western foothills of the Cascades, between the main body of Chuckanut Formation near Bellingham and the main outcrop area of the Swauk Formation south of Mt. Stuart, many smaller bodies of arkosic sandstone have variously been referred to either the Swauk or Chuckanut Formations. The early Eocene Manastash Formation occurs locally in an area south of the Yakima River. The middle to late Eocene Chumstick Formation is mostly confined to the Chiwaukum graben within the crystalline core and is separated from the Swauk Formation on the southwest by the Leavenworth Fault. The Oligocene Wenatchee Formation unconformably over lies the Chumstick Formation near Wenatchee. The middle to late Eocene Roslyn Formation crops out north of the Yakima River and is underlain by the Teanaway Basalt which separates the Roslyn from the older Swauk Formation. The middle Eocene to early Oligocene Naches Formation forms a north-trending body that crosses the Yakima River and is in fault contact with both the Swauk and Manastash Formations. The middle to late Eocene Puget Group underlies the Quaternary deposits of the Puget Lowland southeast of Seattle on the western flank of the Cascades. The various formations are all composed predominantly of fine- to medium-grained sandstones with lesser amounts of interbedded shale, conglomerate and coal. Compositionally, the units are predominantly either feldspathic or litho-feldspathic subquartzose sandstones. Volcanic rocks

Brine/Rock Interaction in Deep Oceanic Layered Gabbros: Petrological Evidence from Cl-Rich Amphibole, High-Temperature Hydrothermal Veins, and Experiments

NASA Astrophysics Data System (ADS)

Currin Sala, A. M.; Koepke, J.; Almeev, R. R.; Teagle, D. A. H.; Zihlmann, B.; Wolff, P. E.

2017-12-01

Evidence of high temperature brine/rock interaction is found in hydrothermal veins and dykelets that cross-cut layered olivine gabbros in the deep palaeocrust of the Sumail Ophiolite, Sultanate of Oman. Here we present petrological and geochemical data from these samples, and an experimental attempt to simulate brine/gabbro interaction using externally heated cold seal pressure vessels. The studied natural veins and dykelets contain pargasite, hornblende, actinolite, and Cl-rich pargasite with up to 5 wt% Cl, showing a range of formation conditions from magmatic to metamorphic (hydrothermal) and thus a complex history of brine/rock interaction. In addition, the isotopic study of the radiogenic 87/86Sr and stable 18O in different amphibole types provide an estimate for the extent of seawater influence as alteration agent in the veins of the studied samples. Experiments performed at 750 °C and 200 MPa with different starting materials (chlorine-free amphibole, olivine gabbro powder) and 20 wt% NaCl aqueous brine, illustrate the process by which gabbro-hosted amphibole-rich veins evolve at subsolidus temperatures in the presence of a seawater-derived fluid. Our results demonstrate a decrease in olivine, plagioclase and magnetite content in favour of hastingsite, pargasite and magnesiohornblende, a decrease of IVAl and Ti in the starting amphibole, and an increase in Cl in amphibole, up to 0.2 Cl wt%. Our experiments show the change of magmatic pargasite towards more magnesium and silica-rich end members with results comparable to mildly chlorine-rich pargasites and hornblendes found in the natural samples studied. However, the experimental setup also presents limitations in the attainment of very high-chlorine amphibole (up to 5 wt%). Our analytical and experimental results provide further evidence for the existence of a hydrothermal cooling system in the deep oceanic crust.

Hurricane genesis: on the breaking African easterly waves and critical layers

NASA Astrophysics Data System (ADS)

Asaadi, Ali; Brunet, Gilbert; Yau, Peter

2015-04-01

This study bring new understanding on the decades-old hurricane genesis problem that starts with westward travelling African easterly waves that can evolve into coherent cyclonic vortices depending on their strength and other nonlinear wave breaking processes. In general, observations indicate that only a small fraction of the African easterly waves that occur in a single hurricane season contribute to tropical cyclogenesis. However, this small fraction includes a large portion of named storms. In addition, a recent study by Dunkerton et al. (2009) has shown that named storms in the Atlantic and eastern Pacific basins are almost all associated with a cyclonic Kelvin "cat's eye" of a tropical easterly wave typical of critical layers, located equatorward of the easterly jet axis. To better understand the dynamics involved in hurricane genesis, the flow characteristics and the physical and dynamical mechanisms by which easterly waves form cat's eyes are investigated with the help of atmospheric reanalyzes and numerical simulations. We perform a climatological study of developing easterly waves covering the 1998-2001 hurricane seasons using ERA-Interim 6-hourly reanalysis data. Composite analyses for all named storms show a monotonic potential vorticity (PV) profile with weak meridional PV gradient and a cyclonic (i.e., south of the easterly jet axis) critical line for time periods of several days preceding the cat's eye formation. In addition, the developing PV anomaly composite shows a statistically significant companion wave-packet of non-developing easterly waves. A barotropic shallow water model is used to study the initial value and forced problems of disturbances on a parabolic jet and realistic profiles associated with weak basic state meridional PV gradients, leading to Kelvin cat's eye formation around the jet axis. The results highlight the synergy of the dynamical mechanisms, including wave breaking and PV redistribution within the nonlinear critical layer

The role of amphibole in Merapi arc magma petrogenesis: insights from petrology and geochemistry of lava hosted xenoliths and xenocrysts

NASA Astrophysics Data System (ADS)

Chadwick, J. P.; Troll, V. R.; Schulz, B.; Dallai, L.; Freda, C.; Schwarzkopf, L. M.; Annersten, H.; Skogby, H.

2010-05-01

Recently, increasing attention has been paid to the role of amphibole in the differentiation of arc magmas. The geochemical composition of these magmas suggests that deep to mid crustal fractionation of amphibole has occurred. However, this phase is typically an infrequent modal phenocryst phase in subduction zone eruptive deposits(1). Nevertheless, erupted material only represents a portion of the magmatism produced in subduction zone settings, with many opportunities for melts to stall on route to the surface. This discrepancy between whole rock geochemistry and petrological interpretation of arc magmas has lead many scientists to postulate that, at mid to deep crustal levels, there may be significant volumes of amphibole bearing lithologies. Amphibole instability at shallow levels can also contribute to its scarcity in eruptive deposits. This argument is strengthened by field and petrological evidence, including the widespread occurrence of amphibole-rich intrusive rocks in exhumed orogenicbelts formed during subduction zone activity, e.g. the Adamello batholith (2),as well as the presence of amphibole-rich xenoliths and xenocrysts preserved in arc lavas worldwide, e.g. in Indonesia, Antilles, and Central America. Thus, amphibole appears to play an integral role in subduction zone magmatism and identifying and constraining this role is central to understanding arc magma petrogenisis. Amphibole-rich melts or bodies in the deep to mid crust could be a significant hydrous reservoir for intra-crustal melts and fluids (1). In this preliminary study, we have carried out petrological and geochemical analyses of recent basaltic andesite and amphibole bearing crystalline igneous inclusions and xenocrysts from Merapi volcano in Java, Indonesia. The basaltic andesite geochemistry is consistent with amphibole fractionation and the crystalline inclusions are cogenetic to the Merapi magmatic system. These inclusions are likely to represent fractionation residues reflecting

Constraints on the depth of generation and emplacement of a magmatic epidote-bearing quartz diorite pluton in the Coast Plutonic Complex, British Columbia

USGS Publications Warehouse

Chang, J.M.; Andronicos, C.L.

2009-01-01

Petrology and P-T estimates indicate that a magmatic epidote-bearing quartz diorite pluton from Mt. Gamsby, Coast Plutonic Complex, British Columbia, was sourced at pressures below ???1.4 GPa and cooled nearly isobarically at ???0.9 GPa. The P-T path indicates that the magma was within the stability field of magmatic epidote early and remained there upon final crystallization. The pluton formed and crystallized at depths greater than ???30 km. REE data indicate that garnet was absent in the melting region and did not fractionate during crystallization. This suggests that the crust was less than or equal to ???55 km thick at 188 Ma during the early phases of magmatism in the Coast Plutonic Complex. Late Cretaceous contractional deformation and early Tertiary extension exhumed the rocks to upper crustal levels. Textures of magmatic epidote and other magmatic phases, combined with REE data, can be important for constraining the P-T path followed by magmas. ?? 2009 Blackwell Publishing Ltd.

Heterogenous Oxygen Isotopic Composition of a Complex Wark-Lovering Rim and the Margin of a Refractory Inclusion from Leoville

NASA Technical Reports Server (NTRS)

Simon, J. I.; Matzel, J. E. P.; Simon, S. B.; Weber, P. K.; Grossman, L.; Ross, D. K.; Hutcheon, I. D.

2014-01-01

Wark-Lovering (WL) rims [1] surrounding many refractory inclusions represent marker events in the early evolution of the Solar System in which many inclusions were exposed to changes in pressure [2], temperature [3], and isotopic reservoirs [4-7]. The effects of these events can be complex, not only producing mineralogical variability of WL rims [2], but also leading to mineralogical [8-10] and isotopic [7, 11, 12] changes within inclusion interiors. Extreme oxygen isotopic heterogeneity measured in CAIs has been explained by mixing between distinct oxygen gas reservoirs in the nebula [13]. Some WL rims contain relatively simple mineral layering and/or are isotopically homogeneous [14, 15]. As part of a larger effort to document and understand the modifications observed in some CAIs, an inclusion (L6) with a complex WL rim from Leoville, a member of the reduced CV3 subgroup was studied. Initial study of the textures and mineral chemistry was presented by [16]. Here we present NanoSIMS oxygen isotopic measurements to complement these petrologic observations.

A petrological view of early Earth geodynamics

NASA Astrophysics Data System (ADS)

Herzberg, C.

2003-04-01

Xenoliths of low T Archean cratonic mantle consist mostly of harzburgite and lherzolite with geochemical depletions that are characterisitc of igneous residues. Many authors have identified the complementary magmas as komatiites. This model is re-examined in light of work presented in Herzberg & O'Hara (2002) and found to be problematic. Munro-type alumina-undepleted komatiites from Alexo, Pyke Hill, and other locations often contain olivine phenocrysts with maximum Mg# \\cong 94. Residues of fractional melting would consist of pure dunite having Mg# = 97-98, but these are not observed. Residues of equilibrium melting would also be pure dunite with Mg# = 94, but these are also not observed. Olivines with Mg# = 94 are found in rare harzburgites, indicating that residues of alumina-undepleted komatiite have either been overprinted by subsequent magmatism or they have been geodynamically eroded. Alumina-undepleted komatiites can be successfully modeled with a primary magma containing 30% MgO produced by 0.5 mass fractions of equilibrium melting of depleted peridotite. A hot plume interpretation is consistent with both the petrology and helium isotopic compositions of alumina-undepleted komatiites. But what about cratonic mantle? The FeO and MgO contents of residues of fertile mantle peridotite formed by both equilibrium and fractional melting can be predicted and applied to xenoliths of cratonic mantle in most cases. Application to xenoliths from the Kaapvaal and Slave cratons is not possible owing to a second stage of Opx enrichment, but results can be applied to most xenoliths from Siberia, Tanzania, Somerset Island, and east Greenland as they contain less than 45% SiO_2. These xenoliths are very similar to residues produced by fractional melting. Pressures of initial melting were mostly 3 to 5 GPa, but can be as high 7 GPa. Pressures of final melting were highly variable and can be as low as 1 GPa. Potential temperatures (T_P) were typically 1450 to 1600oC and

Accounting for mudflow genesis in preliminary assessment of the maximum volume of solid mudflow sediments in the North Caucasus

NASA Astrophysics Data System (ADS)

Zalikhanov, M. Ch.; Kondratieva, N. V.; Adzhiev, A. Kh.; Razumov, V. V.

2016-09-01

The area of investigation was subject to multifactor analysis of the relationship between the maximum amount of mudflow solid sediments ( W) and parameters such as the mudflow basin area ( S), average channel slope (α), and mudflow channel length ( L). They were used to obtain analytical expressions in order to approximate the W( S, L, α) relation based on the mudflow genesis and source height. Statistical data on mudflow manifestations in different basins in the North Caucasus covering more than fifty years were used to obtain the analytical expressions in order to assess the maximum volume of mudflow solid sediments.

Role of otolith endorgans in the genesis of vestibular-visual conflict sickness (pitch) in the squirrel monkey (First report)

NASA Technical Reports Server (NTRS)

Igarashi, Makoto; Himi, Tetsuo; Kulecz, Walter B.; Kobayashi, Kazutoyo

1987-01-01

The effects of ablation of the macula utriculi and macula sacculi on vestibular-visual conflict emesis in squirrel monkeys are investigated. An optokinetic drum and a turntable were used for the direction conflict experiment. A significant difference between the preoperative condition and postunilateral and postbilateral utriculo-sacculectomy conditions is observed. It is detected that after unilateral sacculectomy the conflict sickness decreases and no emesis occurs; however, 4.5 months after sacculectomy, the animals regain their conflict sickness. The data reveal that macular afferents are important in the genesis of sensory conflict emesis and two submodalities may be needed to cause conflict sickness onset.

CM chondrites exhibit the complete petrologic range from type 2 to 1. [Abstract only

NASA Technical Reports Server (NTRS)

Zolensky, M. E.; Browning, L. B.

1994-01-01

Recognition and characterization of the different CM lithologies as components in all meteorites could reveal details of the nature and chronology of alteration and brecciation events on hydrous asteroids. The CM chondrites are of particular interest, as they are the most common carbonaceous chondrites and are found as clasts within other types of meteorites, which suggests that the CM parent asteroids are (or were) widespread in the sections of the asteroid belt providing samples to Earth. Some CM2s, including EET 90047, ALH 83100, and Y 82042, are more 'extensively' altered, and are distinguished by a high proportion of Mg-rich phyllosilicates and Ca-Mg carbonates, frequently in rounded aggregates, and near absence of olivine or pyroxene. 'Completely' altered CMs, called CM1s, essentially lack olivine or pyroxene; these include EET 83334, ALH 88045, and the CM1 clasts in Kaidun. Cold Bokkeveld and EET 84034, both highly brecciated CMs, consist of both extensively and completely altered lithologies. We describe how these lithologies further cosntrain physicochemical conditions on hydrous asteroids. We conclude that CM chondrites exhibit the petrologic range 2 through 1, and that progressive alteration on the parent hydrous asteroid(s) was accompanied by significant increases in temperature (to a peak of approximately 450 C), fO2, water-rock ratio, and (locally) degree of chemical leaching, all well beyond the conditions recorded by CM2s.

Geological and petrologic evolution of seamounts near the EPR based on submersible and camera study

NASA Astrophysics Data System (ADS)

Batiza, Rodey; Smith, Terri L.; Niu, Yaoling

1989-09-01

Observations from 17 ALVIN dives and 14 ANGUS runs plus laboratory study of basalt samples collected with ALVIN help to constrain the morphologic, volcanic and petrologic evolution of four seamounts near the East Pacific Rise (EPR). Comparison among the four volcanoes provides evidence for a general pattern of near-EPR seamount evolution and shows the importance of sedimentation, mass wasting, hydrothermal activity and other geologic processes that occur on submerged oceanic volcanoes. Seamount 5, closest to the EPR (1.0 Ma) is the youngest seamount and may still be active. Its summit is covered by fresh lavas, recent faults and hydrothermal deposits. Seamount D is on crust 1.55 Ma and is inactive; like seamount 5, it has a breached caldera and is composed exclusively of N-MORB. Seamounts 5 and D represent the last stages of growth of typical N-MORB-only seamounts near the EPR axis. Seamounts 6 and 7 have bumpy, flattish summits composed of transitional and alkalic lavas. These lavas probably represent caldera fillings and caps overlying an edifice composed of N-MORB. Evolution from N-MORB-only cratered edifices to the alkalic stage does not occur on all near-EPR seamounts and may be favored by location on structures with relative-motion-parallel orientation.

On the Grand Challenges in Physical Petrology: the Multiphase Crossroads

NASA Astrophysics Data System (ADS)

Bergantz, G. W.

2014-12-01

Rapid progress in experimental, micro-analytical and textural analysis at the crystal scale has produced an unprecedented record of magmatic processes. However an obstacle to further progress is the lack of understanding of how mass, energy and momentum flux associated with crystal-rich, open-system events produces identifiable outcomes. Hence developing a physically-based understanding of magmatic systems linking micro-scale petrological observations with a physical template operating at the macro-scale presents a so-called "Grand Challenge." The essence of this challenge is that magmatic systems have characteristic length and feedback scales between those accessible by classical continuum and discrete methods. It has become increasingly obvious that the old-school continuum methods have limited resolution and power of explanation for multiphase (real) magma dynamics. This is, in part, because in crystal-rich systems the deformation is non-affine, and so the concept of constitutive behavior is less applicable and likely not even relevant, especially if one is interested in the emergent character of micro-scale processes. One expression of this is the cottage industry of proposing viscosity laws for magmas, which serves as "blunt force" de facto corrections for what is intrinsically multiphase behavior. Even in more fluid-rich systems many of these laws are not suitable for use in the very transport theories they aim to support. The alternative approach is the discrete method, where multiphase interactions are explicitly resolved. This is a daunting prospect given the numbers of crystals in magmas. But perhaps all crystals don't need to be modeled. I will demonstrate how discrete methods can recover critical state behavior, resolve crystal migration, the onset of visco-elastic behavior such as melt-present shear bands which sets the large-scale mixing volumes, some of the general morpho-dynamics that underlies purported rheological models, and transient controls on

Coupled petrological-geodynamical modeling of a compositionally heterogeneous mantle plume

NASA Astrophysics Data System (ADS)

Rummel, Lisa; Kaus, Boris J. P.; White, Richard W.; Mertz, Dieter F.; Yang, Jianfeng; Baumann, Tobias S.

2018-01-01

Self-consistent geodynamic modeling that includes melting is challenging as the chemistry of the source rocks continuously changes as a result of melt extraction. Here, we describe a new method to study the interaction between physical and chemical processes in an uprising heterogeneous mantle plume by combining a geodynamic code with a thermodynamic modeling approach for magma generation and evolution. We pre-computed hundreds of phase diagrams, each of them for a different chemical system. After melt is extracted, the phase diagram with the closest bulk rock chemistry to the depleted source rock is updated locally. The petrological evolution of rocks is tracked via evolving chemical compositions of source rocks and extracted melts using twelve oxide compositional parameters. As a result, a wide variety of newly generated magmatic rocks can in principle be produced from mantle rocks with different degrees of depletion. The results show that a variable geothermal gradient, the amount of extracted melt and plume excess temperature affect the magma production and chemistry by influencing decompression melting and the depletion of rocks. Decompression melting is facilitated by a shallower lithosphere-asthenosphere boundary and an increase in the amount of extracted magma is induced by a lower critical melt fraction for melt extraction and/or higher plume temperatures. Increasing critical melt fractions activates the extraction of melts triggered by decompression at a later stage and slows down the depletion process from the metasomatized mantle. Melt compositional trends are used to determine melting related processes by focusing on K2O/Na2O ratio as indicator for the rock type that has been molten. Thus, a step-like-profile in K2O/Na2O might be explained by a transition between melting metasomatized and pyrolitic mantle components reproducible through numerical modeling of a heterogeneous asthenospheric mantle source. A potential application of the developed method

Formation of cratonic lithosphere: An integrated thermal and petrological model

NASA Astrophysics Data System (ADS)

Herzberg, Claude; Rudnick, Roberta

2012-09-01

The formation of cratonic mantle peridotite of Archean age is examined within the time frame of Earth's thermal history, and how it was expressed by temporal variations in magma and residue petrology. Peridotite residues that occupy the lithospheric mantle are rare owing to the effects of melt-rock reaction, metasomatism, and refertilization. Where they are identified, they are very similar to the predicted harzburgite residues of primary magmas of the dominant basalts in greenstone belts, which formed in a non-arc setting (referred to here as "non-arc basalts"). The compositions of these basalts indicate high temperatures of formation that are well-described by the thermal history model of Korenaga. In this model, peridotite residues of extensive ambient mantle melting had the highest Mg-numbers, lowest FeO contents, and lowest densities at ~ 2.5-3.5 Ga. These results are in good agreement with Re-Os ages of kimberlite-hosted cratonic mantle xenoliths and enclosed sulfides, and provide support for the hypothesis of Jordan that low densities of cratonic mantle are a measure of their high preservation potential. Cratonization of the Earth reached its zenith at ~ 2.5-3.5 Ga when ambient mantle was hot and extensive melting produced oceanic crust 30-45 km thick. However, there is a mass imbalance exhibited by the craton-wide distribution of harzburgite residues and the paucity of their complementary magmas that had compositions like the non-arc basalts. We suggest that the problem of the missing basaltic oceanic crust can be resolved by its hydration, cooling and partial transformation to eclogite, which caused foundering of the entire lithosphere. Some of the oceanic crust partially melted during foundering to produce continental crust composed of tonalite-trondhjemite-granodiorite (TTG). The remaining lithosphere gravitationally separated into 1) residual eclogite that continued its descent, and 2) buoyant harzburgite diapirs that rose to underplate cratonic nuclei

Analysis of Solar Wind Samples Returned by Genesis Using Laser Post Ionization Secondary Neutral Mass Spectrometry

NASA Astrophysics Data System (ADS)

Veryovkin, I. V.; Calaway, W. F.; Tripa, C. E.; Pellin, M. J.; Burnett, D. S.

2005-12-01

A new secondary neutral mass spectrometry (SNMS) instrument implementing laser post ionization (LPI) of ion sputtered and laser desorbed neutral species has been developed and constructed for the specific purpose of quantitative analysis of metallic elements at ultra trace levels in solar wind collector samples returned to Earth by the Genesis Discovery mission. The first LPI SNMS measurements are focusing on determining Al, Ca, Cr, and Mg in these samples. These measurements provide the first concentration and isotopic abundances determinations for several key metallic elements and also elucidate possible fractionation effects between the photosphere and the solar wind compositions. It is now documented that Genesis samples suffered surface contamination both during flight and during the breach of the Sample Return Capsule when it crashed. Since accurate quantitative analysis is compromised by sample contamination, several features have been built into the new LPI SNMS instrument to mitigate this difficulty. A normally-incident, low-energy (<500 eV) ion beam combined with a keV energy ion beam and a desorbing laser beam (both microfocused) enables dual beam analyses. The low-energy ion beam can be used to remove surface contaminant by sputtering with minimum ion beam mixing. This low-energy beam also will be used to perform ion beam milling, while either the microfocused ion or laser beam probes the solar wind elemental compositions as a function of sample depth. Because of the high depth resolution of dual beam analyses, such depth profiles clearly distinguish between surface contaminants and solar wind implanted atoms. In addition, in-situ optical and electron beam imaging for observing and avoiding particulates and scratches on solar wind sample surfaces is incorporated in the new LPI SNMS instrument to further reduce quantification problems. The current status of instrument tests and analyses will be presented. This work is supported by the U. S. Department of

Microprocessors as a tool in determining correlation between sferics and tornado genesis: an update

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

Witte, D.R.

1980-09-01

Sferics - atmospheric electromagnetic radiation - can be directly correlated, it is believed, to the genesis of tornadoes and other severe weather. Sferics are generated by lightning and other atmospheric disturbances that are not yet entirely understood. The recording and analysis of the patterns in which sferics events occur, it is hoped, will lead to accurate real-time prediction of tornadoes and other severe weather. Collection of the tremendous amount of sferics data generated by one storm system becomes cumbersome when correlation between at least two stations is necessary for triangulation. Microprocessor-based computing systems have made the task of data collectionmore » and manipulation inexpensive and manageable. The original paper on this subject delivered at MAECON '78 dealt with hardware interfacing. Presented were hardware and software tradeoffs, as well as design and construction techniques to yield a cost effective system. This updated paper presents an overview of where the data comes from, how it is collected, and some current manipulation and interpretation techniques used.« less

Genesis of Bénard-Marangoni Patterns in Thin Liquid Films Drying into Air

NASA Astrophysics Data System (ADS)

Colinet, P.; Chauvet, F.; Dehaeck, S.

Inspired by many years of motivating collaboration between the first author and Prof. Manuel G. Velarde, in the field of surface-tension-driven instabilities, pattern formation, and transition to turbulence, this paper presents recent experimental results obtained in collaboration with the second and third authors at the TIPs laboratory in Brussels. Namely, the evolution of Bénard-like patterns is explored for pure liquid layers evaporating into air, from chaotic regimes down to more stable structures with predominant hexagonal symmetry. Drying liquid layers indeed appear as a particularly simple example of system where, due to the decreasing liquid depth, the preferred wavelength of the pattern is continuously decreased in time, hence requiring perpetual creation of new convective cells. Such pattern "genesis" appears to lead to disordered structures with interesting characteristics, whose preliminary experimental investigation is carried out here. This paper is dedicated to Prof. Manuel G. Velarde, at the occasion of his 70th birthday, as a mark of deep gratitude for all positive scientific and cultural influences he had and he still has on many young scientists.

The Genesis of Atlantic Lows Experiment: The Planetary-Boundary-Layer Subprogram of GALE.

NASA Astrophysics Data System (ADS)

Raman, Sethu; Riordan, Allen J.

1988-02-01

The Genesis of Atlantic Lows Experiment (GALE), focused an intensive data-gathering effort along the mid-Atlantic coast of the United States from 15 January through 15 March 1986. Here, the general objectives and experimental layout are described with special emphasis on the planetary-boundary-layer (PBL) component of GALE.Instrumentation is described for buoys, ships, research aircraft, and towers. The networks of the cross-chain long range aid to navigation (LORAN) atmospheric sounding system (CLASS) and the portable automated mesonet (PAM II) are described and their impact on the operation of GALE is outlined. Special use of dual-Doppler radar to obtain detailed wind measurements in the PBL is discussed.Preliminary analyses for a selected observational period are given. Detailed observations of the offshore coastal front reveal direct mesoscale circulations imbedded in the frontal zone. Later in the period, during an intense cold-air outbreak, sensible-heat and latent-heat fluxes over the coastal ocean each attain values of about 500 W · m2. Coordinated aircraft operations are outlined for this case and a few early findings are given.

Genesis of Microstructures in Friction Stir Welding of Ti-6Al-4V

NASA Astrophysics Data System (ADS)

Tchein, Gnofam Jacques; Jacquin, Dimitri; Coupard, Dominique; Lacoste, Eric; Girot Mata, Franck

2018-06-01

This paper is focused on the genesis of microstructures in friction stir welding (FSW) of the Ti-6Al-4V alloy. Several titanium joints, initially prepared with four different preheat treatments, were processed by FSW. Detailed microstructural analyses were performed in order to investigate change in the microstructure during the process. In this work, the FSW processing allows a controlled and stable microstructure to be produced in the stirring zone, regardless of the initial heat treatment or the welding conditions. The welded material undergoes a severe thermomechanical treatment which can be divided into two steps. First, the friction in the shoulder and the plastic strain give rise to the necessary conditions to allow a continuous dynamic recrystallization of the β phase. This operation produces a fine and equiaxed β grain structure. Second, once the pin has moved away, the temperature decreases, and the material undergoes a heat treatment equivalent to air quenching. The material thus exhibits a β → β + α transformation with germination of a fine intergranular Widmanstätten phase within the ex-fully-recrystallized- β grains.

Composition and petrology of HED polymict breccias: The regolith of (4) Vesta

NASA Astrophysics Data System (ADS)

Mittlefehldt, David W.; Herrin, Jason S.; Quinn, Julie E.; Mertzman, Stanley A.; Cartwright, Julia A.; Mertzman, Karen R.; Peng, Zhan X.

2013-11-01

We have done petrologic and compositional studies on a suite of polymict eucrites and howardites to better understand regolith processes on their parent asteroid, which we accept is (4) Vesta. Taking into account noble gas results from companion studies, we interpret five howardites to represent breccias assembled from the true regolith: Elephant Moraine (EET) 87513, Grosvenor Mountains (GRO) 95535, GRO 95602, Lewis Cliff (LEW) 85313, and Meteorite Hills (MET) 00423. We suggest that EET 87503 is paired with EET 87513, and thus is also regolithic. Pecora Escarpment (PCA) 02066 is dominated by melt-matrix clasts, which may have been formed from true regolith by impact melting. These meteorites display a range in eucrite:diogenite mixing ratio from 55:45 to 76:24. There is no correlation between degree of regolith character and Ni content. The Ni contents of howardite, eucrite, and diogenites (HEDs) are mostly controlled by the distribution of coarse chondritic clasts and metal grains, which in some cases resulted from individual, low-velocity accretion events, rather than extensive regolith gardening. Trace element compositions indicate that the mafic component of HED polymict breccias is mostly basalt similar to main-group eucrites; Stannern-trend basaltic debris is less common. Pyroxene compositions show that some trace element-rich howardites contain abundant debris from evolved basalts, and that cumulate gabbro debris is present in some breccias. The scale of heterogeneity varies considerably; regolithic howardite EET 87513 is more homogeneous than fragmental howardite Queen Alexandra Range (QUE) 97001. Individual samples of a given howardite can have different compositions even at roughly 5 g masses, indicating that obtaining representative meteorite compositions requires multiple or large samples.

Geological and petrological considerations relevant to the disposal of radioactive wastes by hydraulic fracturing: an example at the US Department of Energy's Oak Ridge National Laboratory. [Pumpkin Valley shales

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

Haase, C.S.

1982-01-01

At Oak Ridge National Laboratory the Pumpkin Valley Shale is used as a host formation for hydraulic-fracturing waste disposal. Determination of the relationships between the distribution of different lithologies and porosity-permeability trends within this host formation allows these properties, important to hydraulic-fracturing operations, to be related to measurable and mappable geological and petrological parameters. It also permits extrapolation of such patterns to little-studied portions of the Pumpkin Valley Shale. Such knowledge better allows for the satisfactory operation and assessment of the hydraulic fracturing at Oak Ridge National Laboratory.

Origin of dolomitic rocks in the lower Permian Fengcheng formation, Junggar Basin, China: evidence from petrology and geochemistry

NASA Astrophysics Data System (ADS)

Zhu, Shifa; Qin, Yi; Liu, Xin; Wei, Chengjie; Zhu, Xiaomin; Zhang, Wei

2017-04-01

Although dolomitization of calcite minerals and carbonatization of volcanic rocks have been studied widely, the extensive dolomitic rocks that originated from altered volcanic and volcaniclastic rocks have not been reported. The dolomitic rocks of the Fengcheng Formation in the Junggar Basin of China appear to be formed under unusual geologic conditions. The petrological and geochemical characteristics indicate that the dolomitizing host rock is devitrified volcanic tuff. After low-temperature alteration and calcitization, these tuffaceous rocks are replaced by Mg-rich brine to form massive dolomitic tuffs. We propose that the briny (with -2 ‰ 6 ‰ of δ13CPDB and -5 ‰ 4 ‰ of δ18OPDB) and Mg-rich marine formation water (with 0.7060 0.7087 of 87Sr/86Sr ratio), the thick and intermediate-mafic volcanic ashes, and the tectonically compressional movement may have favored the formation of the unusual dolomitic rocks. We conclude that the proposed origin of the dolomitic rocks can be extrapolated to other similar terranes with volcaniclastic rocks, seabed tuffaceous sediment, and fracture filling of sill.

Maternal perceptions of their child's weight status: the GENESIS study.

PubMed

Manios, Yannis; Kondaki, Katerina; Kourlaba, Georgia; Vasilopoulou, Emilia; Grammatikaki, Evangelia

2009-08-01

The objective of the present work was to quantify mothers' misclassification of pre-school children's weight status and to determine factors associated with the maternal misperception. A representative sample of 2287 children aged 2-5 years was examined (GENESIS study). Mothers' perceptions of their child's weight status and the children's and mothers' anthropometric and other characteristics (sociodemographic and lifestyle) were recorded. Almost 38 % of mothers underestimated their child's weight status. The frequency of underestimation was much higher among 'at risk of being overweight' and 'overweight' children (88.3 % and 54.5 %, respectively) compared with 'underweight/normal-weight' children (18.0 %, P < 0.001). Multiple logistic regression modelling revealed that the likelihood of mothers' underestimation of their child's weight status was significantly higher in boys, in children engaging in physical activity for less than 3 h/week and in children whose mothers had low education status, compared with their counterparts. Moreover, the higher the BMI-for-age Z-score, the greater the odds that the mother would underestimate her child's weight status. The current study demonstrated that more than one-third of mothers misclassify their children's weight status as being lower than the actual. Given that mother's weight perception might be an important determinant of child's body weight development, clinicians and health professionals should help mothers correctly classify their children's weight status, which could potentially help in the early prevention of overweight and obesity.

Polychronous (Early Cretaceous to Palaeogene) emplacement of the Mundwara alkaline complex, Rajasthan, India: 40Ar/39Ar geochronology, petrochemistry and geodynamics

NASA Astrophysics Data System (ADS)

Pande, Kanchan; Cucciniello, Ciro; Sheth, Hetu; Vijayan, Anjali; Sharma, Kamal Kant; Purohit, Ritesh; Jagadeesan, K. C.; Shinde, Sapna

2017-07-01

The Mundwara alkaline plutonic complex (Rajasthan, north-western India) is considered a part of the Late Cretaceous-Palaeogene Deccan Traps flood basalt province, based on geochronological data (mainly 40Ar/39Ar, on whole rocks, biotite and hornblende). We have studied the petrology and mineral chemistry of some Mundwara mafic rocks containing mica and amphibole. Geothermobarometry indicates emplacement of the complex at middle to upper crustal levels. We have obtained new 40Ar/39Ar ages of 80-84 Ma on biotite separates from mafic rocks and 102-110 Ma on whole-rock nepheline syenites. There is no evidence for excess 40Ar. The combined results show that some of the constituent intrusions of the Mundwara complex are of Deccan age, but others are older and unrelated to the Deccan Traps. The Mundwara alkaline complex is thus polychronous and similar to many alkaline complexes around the world that show recurrent magmatism, sometimes over hundreds of millions of years. The primary biotite and amphibole in Mundwara mafic rocks indicate hydrous parental magmas, derived from hydrated mantle peridotite at relatively low temperatures, thus ruling out a mantle plume. This hydration and metasomatism of the Rajasthan lithospheric mantle may have occurred during Jurassic subduction under Gondwanaland, or Precambrian subduction events. Low-degree decompression melting of this old, enriched lithospheric mantle, due to periodic diffuse lithospheric extension, gradually built the Mundwara complex from the Early Cretaceous to Palaeogene time.

New Petrology, Mineral Chemistry and Stable MG Isotope Compositions of an Allende CAI: EK-459-7-2

NASA Technical Reports Server (NTRS)

Jeffcoat, C. R.; Kerekgyarto, A. G.; Lapen, T. J.; Righter, M.; Simon, J. I.; Ross, D. K.

2016-01-01

Calcium-aluminum-rich inclusions (CAIs) are the key to understanding physical and chemical conditions in the nascent solar nebula. These inclusions have the oldest radiometric ages of solar system materials and are composed of phases that are predicted to condense early from a gas of solar composition. Thus, their chemistry and textures record conditions and processes in the earliest stages of development of the solar nebula. Type B inclusions are typically larger and more coarse grained than other types with substantial evidence that many of them were at least partially molten. Type B inclusions are further subdivided into Type B1 (possess thick melilite mantle) and Type B2 (lack melilite mantle). Despite being extensively studied, the origin of the melilite mantles of Type B1 inclusions remains uncertain. We present petrologic and chemical data for a Type B inclusion, EK-459-7-2, that bears features found in both Type B1 and B2 inclusions and likely represents an intermediate between the two types. Detailed studies of more of these intermediate objects may help to constrain models for Type B1 rim formation.