Proton probe analysis of an irghizite and a high-magnesium Java tektite     

D.M. Van Patter  C.P. Swann  Billy P. Glass 《Geochimica et cosmochimica acta》1981,45(2):229-234

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Major element compositions of Luna 20 glass particles     

Billy P. Glass 《Geochimica et cosmochimica acta》1973,37(4):841-846

Major element analyses of nineteen Luna 20 glass particles indicate that most of the Luna 20 glasses have Al₂O₃ contents greater than 21 wt.% and compositions similar to Apollo 10 and Luna 20 rocks and soils. Three of the glass particles have low Al₂O₃ (< 13 wt.%) and high FeO (> 18 wt.%) contents and were probably derived from one of the adjacent maria. The low glass content of the Luna 20 soil indicates that it is relatively young or less mature than most mare soils that have been studied.  相似文献   

October 2003     

Katherine Stone  Orville Magoon  Billy Edge  Lesley Ewing 《Environmental Geology》2003,44(7):876-875

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Nd and Sr isotopic compositions of tektite material from Barbados and their relationship to North American tektites     

Henry H. Ngo  Gerald J. Wasserburg  Billy P. Glass 《Geochimica et cosmochimica acta》1985,49(6):1479-1485

Isotopic analyses of Nd and Sr on individual microtektites and a bulk microtektite sample from Barbados show them to have a very well defined isotopic composition. These data plot on an ε_Srε_Nd diagram precisely within the narrow field determined by North American tektites (ε_Sr ≈ 111; ε_Nd ≈ ?6.2). They yield an Nd model age of 0.6 AE. These results show that the microtektites from the Oceanic beds of late Eocene age are derived from the same target as the North American tektites and should be associated with the same event. Samples of the deep sea sediments in which the Barbados microtektites occur are found to have isotopic signatures which appear to reflect ambient sea water and detrital sediments. They cannot be the source of Sr or Nd in the tektites. Following the arguments of Shaw and Wasserburg (1982) we conclude that the target area which produced the North American tektite field was composed of sediments (Eocambrian or younger) derived from very late Precambrian crust. Glass beads from Lake Wanapitei Crater are isotopically different from all other tektites (ε_Sr ≈ 960; ε_Nd ≈ ?31.4) and cannot be related to the North American tektites.  相似文献   

The kpc-scale radio source population     

P. Augusto  J. I. Gonzalez-Serrano  A. C. Edge  N. A. B. Gizani  P. N. Wilkinson  I. Perez-Fournon 《New Astronomy Reviews》1999,43(8-10)

We are conducting a multi-wavelength (radio, optical, and X-ray) observational campaign to classify, morphologically and physically, a sample of 55 flat-spectrum radio sources dominated by structure on kpc-scales. This sample contains 22 compact-/medium-sized symmetric object candidates, a class of objects thought to be in the early stages of the evolution of radio galaxies. The vast majority of the remaining objects have core-plus-one-sided-jet structures, half of which show sharply bent jets, probably due to strong interactions with the interstellar medium of the host galaxies. Once the observational campaign is completed, we will constrain evolutionary theories of radio galaxies at their intermediate stages and possibly understand the physics of the hypothesised narrow-line region in active galactic nuclei, given our advantageous statistical position.  相似文献   

Coesite in a Muong Nong‐type tektite from Muong Phin,Laos: Description,formation, and survival     

Billy P. Glass  Luigi Folco  Matteo Masotta  Fabrizio Campanale 《Meteoritics & planetary science》2020,55(2):253-273

We examined 16 white opaque inclusions exposed on two polished slices of a Muong Nong‐type Australasian tektite from Muong Phin, Laos. The inclusions usually consist of a core, surrounded by a froth layer, and a quartz neoblast layer. The cores are composed primarily of a mixture of silica glass, coesite, and quartz in varying proportions. A thin (up to ~4 μm) layer of SiO₂‐poor glass enriched in FeO, MgO, CaO, Al₂O₃, and TiO₂ is observed as a bright halo in backscattered electron images around the quartz neoblasts and in places contains μm‐sized crystals, which may be Fe,Mg‐rich spinel. The distribution and textural relationships between the coesite‐bearing inclusions and the tektite matrix point to an in situ formation of the coesite due to an impact, rather than to infall, from a nearby impact, into tektite melt produced by the aerial burst of a bolide. The quartz neoblasts probably formed by crystallization of silica melt squeezed out of the inclusion core during the development of the froth layer. The bright halo may be the result of silica diffusing from the adjacent tektite melt into the growing quartz neoblasts. We propose that the survival of coesite was possible due to the froth layer that acted as a heat sink during bubble expansion and then as a thermal insulator.  相似文献   

A preliminary investigation of the fish food web in the Gironde estuary,France, using dietary and stable isotope analyses     

S. Pasquaud  P. Elie  C. Jeantet  I. Billy  P. Martinez  M. Girardin 《Estuarine, Coastal and Shelf Science》2008

Carbon and Nitrogen stable isotopes and stomach contents analyses were used to investigate an estuarine fish food web and identify the contribution of these two methods to the knowledge and understanding of the food web's structure and its functioning. The nine most abundant fish species during the warm period in the Gironde estuary (southwest France, Europe) are examined. Observation of the stomach contents reflects a variety of feeding modes between fish species that consume a diverse assortment of prey, with limited dietary overlap. Nevertheless, when regarding the whole fish community, few prey species dominate the stomach contents. Nitrogen isotope ratios indicate a high intraspecific variability inducing an interspecific covering of the signatures. However, a tendency to δ¹⁵N enrichment according to the trophic position of the species studied was observed. Fish assemblages show a trend towards enrichment of their carbon isotopic signatures from the upper estuary (−20.8 ± 1.8‰) towards the lower estuary (−18.3 ± 1.6‰). But whatever the capture zone considered, most of the individual δ¹³C values for each fish analysed are comprised between −22 and −16‰. Only few specimens, belonging to migratory amphihaline species, have significantly lighter values.  相似文献   

The 2dF-SDSS LRG and QSO Survey: evolution of the clustering of luminous red galaxies since z= 0.6     

David A. Wake  Ravi K. Sheth  Robert C. Nichol  Carlton M. Baugh  Joss Bland-Hawthorn  Matthew Colless  Warrick J. Couch  Scott M. Croom  Roberto De Propris  Michael J. Drinkwater  Alastair C. Edge  Jon Loveday  Tsz Yan Lam  Kevin A. Pimbblet  Isaac G. Roseboom  Nicholas P. Ross  Donald P. Schneider  Tom Shanks  Robert G. Sharp 《Monthly notices of the Royal Astronomical Society》2008,387(3):1045-1062

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The 2dF-SDSS LRG and QSO Survey: the LRG 2-point correlation function and redshift-space distortions     

Nicholas P. Ross  J. da Ângela  T. Shanks  David A. Wake  Russell D. Cannon  A. C. Edge  R. C. Nichol  P. J. Outram  Matthew Colless  Warrick J. Couch  Scott M. Croom  Roberto De Propris  Michael J. Drinkwater  Daniel J. Eisenstein  Jon Loveday  Kevin A. Pimbblet  Isaac G. Roseboom  Donald P. Schneider  Robert G. Sharp  P. M. Weilbacher 《Monthly notices of the Royal Astronomical Society》2007,381(2):573-588

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The detection of dust in the central galaxies of distant cooling-flow clusters     

A. C. Edge  R. J. Ivison  Ian Smail  A. W. Blain  J.-P. Kneib 《Monthly notices of the Royal Astronomical Society》1999,306(3):599-606

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